From 6a22bacaf085046b6b706eb6931e8c3a77e4daa7 Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Sun, 8 Oct 2023 23:14:25 +0900
Subject: [PATCH 01/31] Add new benchmark script `fib.ss`

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md           |  6 +++---
 VERSION             |  2 +-
 benchmark/fib.ss    | 15 +++++++++++++++
 script/benchmark.sh | 15 ++++++++-------
 4 files changed, 27 insertions(+), 11 deletions(-)
 create mode 100644 benchmark/fib.ss

diff --git a/README.md b/README.md
index 9fab71bc0..0da0df626 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.32_amd64.deb
+sudo apt install build/meevax_0.5.33_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.32.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.33.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.32_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.33_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index 32a910026..62b3483cd 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.32
+0.5.33
diff --git a/benchmark/fib.ss b/benchmark/fib.ss
new file mode 100644
index 000000000..87dcdb05f
--- /dev/null
+++ b/benchmark/fib.ss
@@ -0,0 +1,15 @@
+(import (scheme base)
+        (scheme write)
+        (scheme process-context))
+
+(define (fib n)
+  (if (< n 2)
+      n
+      (+ (fib (- n 1))
+         (fib (- n 2)))))
+
+; (fib 20) = 6765
+; (fib 30) = 832040
+; (fib 40) = 102334155
+
+(exit (= (fib 30) 832040))
diff --git a/script/benchmark.sh b/script/benchmark.sh
index 6d3e81e6e..4201d0d2c 100755
--- a/script/benchmark.sh
+++ b/script/benchmark.sh
@@ -5,6 +5,7 @@ root="$(git rev-parse --show-toplevel)"
 scripts()
 {
   echo ack
+  echo fib
   echo tarai
 }
 
@@ -20,19 +21,19 @@ quotient()
 
 tsv()
 {
-  printf "script\tMeevax\tGauche\tChibi\n"
+  printf "script\tMeevax\tChibi-Scheme\tGauche\n"
 
   for each in $(scripts)
   do
-    time_m=$(real meevax       "$root/benchmark/$each.ss")
-    time_g=$(real gosh         "$root/benchmark/$each.ss")
-    time_c=$(real chibi-scheme "$root/benchmark/$each.ss")
+    t0=$(real meevax       "$root/benchmark/$each.ss")
+    t1=$(real chibi-scheme "$root/benchmark/$each.ss")
+    t2=$(real gosh         "$root/benchmark/$each.ss")
 
     printf "%s\t%s\t%s\t%s\n" \
       "$each" \
-      "$time_m" \
-      "$time_g ($(quotient "$time_m" "$time_g"))" \
-      "$time_c ($(quotient "$time_m" "$time_c"))"
+      "$t0" \
+      "$t1 (x$(quotient "$t0" "$t1"))" \
+      "$t2 (x$(quotient "$t0" "$t2"))"
   done
 }
 

From ad6a8431975d4cbac1f6a0b63ea40fd7157d7cf9 Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Tue, 10 Oct 2023 12:58:46 +0900
Subject: [PATCH 02/31] Cleanup struct `optimizer`

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md                                     |  6 +-
 VERSION                                       |  2 +-
 include/meevax/kernel/dynamic_environment.hpp |  4 +-
 include/meevax/kernel/instruction.hpp         | 38 ++++++++++-
 include/meevax/kernel/optimizer.hpp           | 64 +++++++++----------
 src/kernel/instruction.cpp                    | 39 -----------
 6 files changed, 72 insertions(+), 81 deletions(-)

diff --git a/README.md b/README.md
index 0da0df626..473b4dda2 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.33_amd64.deb
+sudo apt install build/meevax_0.5.34_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.33.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.34.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.33_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.34_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index 62b3483cd..c0490e56c 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.33
+0.5.34
diff --git a/include/meevax/kernel/dynamic_environment.hpp b/include/meevax/kernel/dynamic_environment.hpp
index aaf2f4b85..62a6db453 100644
--- a/include/meevax/kernel/dynamic_environment.hpp
+++ b/include/meevax/kernel/dynamic_environment.hpp
@@ -220,9 +220,9 @@ inline namespace kernel
 
         case instruction::load_continuation: /* --------------------------------
           *
-          *  s e (%load-continuation c1 . c2) d => ((<continuation>) . s) e c2 d
+          *  s e (%load-continuation c' . c) d => ((<continuation>) . s) e c d
           *
-          *  where <continuation> = (s e c1 . d)
+          *  where <continuation> = (s e c' . d)
           *
           * ----------------------------------------------------------------- */
           s = cons(list(make<continuation>(s, e, cadr(c), d)), s);
diff --git a/include/meevax/kernel/instruction.hpp b/include/meevax/kernel/instruction.hpp
index 4aaa0751b..0a9f68c72 100644
--- a/include/meevax/kernel/instruction.hpp
+++ b/include/meevax/kernel/instruction.hpp
@@ -52,7 +52,43 @@ inline namespace kernel
 
   auto operator <<(std::ostream &, instruction const&) -> std::ostream &;
 
-  auto instruction_length(instruction const&) -> std::size_t;
+  constexpr auto size(instruction const& datum)
+  {
+    switch (datum)
+    {
+      case instruction::call:
+      case instruction::cons:
+      case instruction::drop:
+      case instruction::dummy:
+      case instruction::join:
+      case instruction::letrec:
+      case instruction::return_:
+      case instruction::stop:
+      case instruction::tail_call:
+      case instruction::tail_letrec:
+        return 1;
+
+      case instruction::current:
+      case instruction::install:
+      case instruction::load_absolute:
+      case instruction::load_closure:
+      case instruction::load_constant:
+      case instruction::load_continuation:
+      case instruction::load_relative:
+      case instruction::load_variadic:
+      case instruction::store_absolute:
+      case instruction::store_relative:
+      case instruction::store_variadic:
+        return 2;
+
+      case instruction::select:
+      case instruction::tail_select:
+        return 3;
+
+      default:
+        return 0;
+    }
+  }
 } // namespace kernel
 } // namespace meevax
 
diff --git a/include/meevax/kernel/optimizer.hpp b/include/meevax/kernel/optimizer.hpp
index 14facd586..fb5fa0068 100644
--- a/include/meevax/kernel/optimizer.hpp
+++ b/include/meevax/kernel/optimizer.hpp
@@ -29,11 +29,11 @@ inline namespace kernel
 
     static auto merge_constants(object const& c) -> object
     {
-      if (not c.is<pair>())
+      if (not c.is<pair>() or not c[0].is<instruction>())
       {
         return c;
       }
-      else switch (c[0].as<instruction>())
+      else switch (auto n = size(c[0].as<instruction>()); c[0].as<instruction>())
       {
       case instruction::load_constant: /* --------------------------------------
       *
@@ -42,70 +42,64 @@ inline namespace kernel
       *   cons
       *   ...)
       *
-      *  => (load-constant (x . y)
+      *  => (load-constant (y . x)
       *      ...)
       *
       * --------------------------------------------------------------------- */
-        if (5 <= length(c) and
-            c[0].is<instruction>() and
-            c[0].as<instruction>() == instruction::load_constant and
-            c[2].is<instruction>() and
-            c[2].as<instruction>() == instruction::load_constant and
-            c[4].is<instruction>() and
-            c[4].as<instruction>() == instruction::cons)
+        if (tail(c, 2).is<pair>() and c[2].is<instruction>() and c[2].as<instruction>() == instruction::load_constant and
+            tail(c, 4).is<pair>() and c[4].is<instruction>() and c[4].as<instruction>() == instruction::cons)
         {
           return merge_constants(cons(c[0],
                                       cons(c[3], c[1]),
                                       merge_constants(tail(c, 5))));
         }
-        else if (let const& continuation = merge_constants(cddr(c)); continuation == cddr(c))
+        else if (let const& c2 = merge_constants(tail(c, 2)); c2 == tail(c, 2))
         {
           return c;
         }
         else
         {
-          return cons(car(c), cadr(c), continuation);
+          return cons(c[0], c[1], c2);
+        }
+
+      default:
+        if (let const& cn = merge_constants(tail(c, n)); cn == tail(c, n))
+        {
+          return c;
+        }
+        else
+        {
+          return append(take(c, n), cn);
         }
 
       case instruction::load_closure:
       case instruction::load_continuation:
-        if (let const& subcontrol   = merge_constants(cadr(c)),
-                       continuation = merge_constants(cddr(c));
-            subcontrol == cadr(c) and continuation == cddr(c))
+        if (let const& c1 = merge_constants(head(c, 1)),
+                       c2 = merge_constants(tail(c, 2));
+            c1 == head(c, 1) and
+            c2 == tail(c, 2))
         {
           return c;
         }
         else
         {
-          return cons(c[0], subcontrol, continuation);
+          return cons(c[0], c1, c2);
         }
 
       case instruction::select:
       case instruction::tail_select:
-        if (let const& consequent   = merge_constants(cadr(c)),
-                       alternate    = merge_constants(caddr(c)),
-                       continuation = merge_constants(cdddr(c));
-            consequent == cadr(c) and alternate == caddr(c) and continuation == cdddr(c))
+        if (let const& c1 = merge_constants(head(c, 1)),
+                       c2 = merge_constants(head(c, 2)),
+                       c3 = merge_constants(tail(c, 3));
+            c1 == head(c, 1) and
+            c2 == head(c, 2) and
+            c3 == tail(c, 3))
         {
           return c;
         }
         else
         {
-          return cons(c[0], consequent, alternate, continuation);
-        }
-
-      default:
-        {
-          auto length = instruction_length(c[0].as<instruction>());
-
-          if (let const& continuation = merge_constants(tail(c, length)); continuation == tail(c, length))
-          {
-            return c;
-          }
-          else
-          {
-            return append(take(c, length), continuation);
-          }
+          return cons(c[0], c1, c2, c3);
         }
       }
     }
diff --git a/src/kernel/instruction.cpp b/src/kernel/instruction.cpp
index 09469e96f..f2cb1ada6 100644
--- a/src/kernel/instruction.cpp
+++ b/src/kernel/instruction.cpp
@@ -55,44 +55,5 @@ inline namespace kernel
         return os;
     }
   }
-
-  auto instruction_length(instruction const& datum) -> std::size_t
-  {
-    switch (datum)
-    {
-      case instruction::call:
-      case instruction::cons:
-      case instruction::drop:
-      case instruction::dummy:
-      case instruction::join:
-      case instruction::letrec:
-      case instruction::return_:
-      case instruction::stop:
-      case instruction::tail_call:
-      case instruction::tail_letrec:
-        return 1;
-
-      case instruction::current:
-      case instruction::install:
-      case instruction::load_absolute:
-      case instruction::load_closure:
-      case instruction::load_constant:
-      case instruction::load_continuation:
-      case instruction::load_relative:
-      case instruction::load_variadic:
-      case instruction::store_absolute:
-      case instruction::store_relative:
-      case instruction::store_variadic:
-        return 2;
-
-      case instruction::select:
-      case instruction::tail_select:
-        return 3;
-
-      default:
-        assert(false);
-        return 0;
-    }
-  }
 } // namespace kernel
 } // namespace meevax

From 0010edad7817e3a1092db9a75dd1e8e246a2e19d Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Thu, 12 Oct 2023 01:20:23 +0900
Subject: [PATCH 03/31] Update SRFI 39 to use built-in procedures as much as
 possible

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md                             |  6 +--
 VERSION                               |  2 +-
 basis/srfi-39.ss                      | 73 +++++++++++++++++----------
 include/meevax/memory/pointer_set.hpp | 32 ++++--------
 include/meevax/utility/debug.hpp      |  4 +-
 src/memory/collector.cpp              |  4 +-
 6 files changed, 64 insertions(+), 57 deletions(-)

diff --git a/README.md b/README.md
index 473b4dda2..76435467a 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.34_amd64.deb
+sudo apt install build/meevax_0.5.35_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.34.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.35.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.34_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.35_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index c0490e56c..0defa4dc0 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.34
+0.5.35
diff --git a/basis/srfi-39.ss b/basis/srfi-39.ss
index 00e047a61..85abb1c21 100644
--- a/basis/srfi-39.ss
+++ b/basis/srfi-39.ss
@@ -22,8 +22,13 @@
 
 (define-library (srfi 39)
   (import (only (meevax core) current install)
+          (only (meevax continuation) dynamic-wind)
+          (only (meevax core) define define-syntax if lambda letrec quote)
+          (only (meevax list) null? list append assq)
           (only (meevax macro-transformer) er-macro-transformer)
-          (scheme r5rs))
+          (only (meevax pair) cons car cdr cadr cddr set-car! set-cdr!)
+          (only (scheme r5rs) map)
+          )
 
   (export make-parameter parameterize)
 
@@ -33,36 +38,48 @@
          (define (install-dynamic-bindings! bindings)
            (install 1 bindings))
 
-         (define (make-parameter init . converter)
-           (let* ((convert (if (null? converter)
-                               (lambda (x) x)
-                               (car converter)))
-                  (default (cons #f (convert init))))
-             (letrec ((parameter
-                        (lambda value
-                          (let ((cell (or (assq parameter (current-dynamic-bindings)) default)))
-                            (cond ((null? value)
-                                   (cdr cell))
-                                  ((null? (cdr value))
-                                   (set-cdr! cell (convert (car value))))
-                                  (else ; Apply converter to value
-                                    (convert (car value))))))))
-               (set-car! default parameter)
-               parameter)))
+         (define (make-parameter init . convert)
+           ((lambda (convert)
+              ((lambda (default)
+                 (letrec ((parameter
+                            (lambda value
+                              ((lambda (cell)
+                                 (if (null? value)
+                                     (cdr cell)
+                                     (if (null? (cdr value))
+                                         (set-cdr! cell (convert (car value)))
+                                         (convert (car value)))))
+                               ((lambda (current-dynamic-binding)
+                                  (if current-dynamic-binding
+                                      current-dynamic-binding
+                                      default))
+                                (assq parameter (current-dynamic-bindings)))))))
+                   (set-car! default parameter)
+                   parameter))
+               (cons #f (convert init))))
+            (if (null? convert)
+                (lambda (x) x)
+                (car convert))))
 
          (define (dynamic-bind parameters values body)
-           (let* ((outer (current-dynamic-bindings))
-                  (inner (map (lambda (parameter value)
-                                (cons parameter (parameter value 'apply-converter-to-value)))
-                              parameters
-                              values)))
-             (dynamic-wind (lambda () (install-dynamic-bindings! (append inner outer)))
-                           body
-                           (lambda () (install-dynamic-bindings! outer)))))
+           ((lambda (outer inner)
+              (dynamic-wind (lambda () (install-dynamic-bindings! (append inner outer)))
+                            body
+                            (lambda () (install-dynamic-bindings! outer))))
+            (current-dynamic-bindings)
+            (map (lambda (parameter value)
+                   (cons parameter (parameter value 'convert)))
+                 parameters
+                 values)))
 
          (define-syntax parameterize
            (er-macro-transformer
              (lambda (form rename compare)
-               `(,(rename 'dynamic-bind) (,(rename 'list) ,@(map car (cadr form)))
-                                         (,(rename 'list) ,@(map cadr (cadr form)))
-                                         (,(rename 'lambda) () ,@(cddr form))))))))
+               (list (rename 'dynamic-bind)
+                     (cons (rename 'list)
+                           (map car (cadr form)))
+                     (cons (rename 'list)
+                           (map cadr (cadr form)))
+                     (cons (rename 'lambda)
+                           (cons '()
+                                 (cddr form)))))))))
diff --git a/include/meevax/memory/pointer_set.hpp b/include/meevax/memory/pointer_set.hpp
index 9a0f9d615..26468e057 100644
--- a/include/meevax/memory/pointer_set.hpp
+++ b/include/meevax/memory/pointer_set.hpp
@@ -75,27 +75,15 @@ inline namespace memory
       }
     };
 
-    struct chunk
+    struct chunk : public std::array<bool, Capacity>
     {
       std::size_t offset;
 
-      bool data[Capacity];
-
       explicit constexpr chunk(compact_pointer const p)
-        : offset { p.offset() }
-        , data { false }
-      {
-        data[p.index()] = true;
-      }
-
-      constexpr auto operator [](std::size_t index) const noexcept -> decltype(auto)
+        : std::array<bool, Capacity> { false }
+        , offset { p.offset() }
       {
-        return data[index];
-      }
-
-      constexpr auto operator [](std::size_t index) noexcept -> decltype(auto)
-      {
-        return data[index];
+        (*this)[p.index()] = true;
       }
 
       constexpr auto operator <(compact_pointer p) noexcept
@@ -121,13 +109,15 @@ inline namespace memory
 
       std::vector<chunk> const& chunks;
 
-      std::size_t i, j;
+      std::size_t i;
+
+      std::size_t j;
 
       explicit iterator(std::vector<chunk> const& chunks,
-                        std::size_t i,
+                        typename std::vector<chunk>::const_iterator iter,
                         std::size_t j) noexcept
         : chunks { chunks }
-        , i      { i }
+        , i      { static_cast<std::size_t>(std::distance(chunks.begin(), iter)) }
         , j      { j }
       {
         if (not (i < chunks.size() and j < Capacity and chunks[i][j]))
@@ -260,7 +250,7 @@ inline namespace memory
 
     auto begin() const noexcept
     {
-      return iterator(chunks, 0, 0);
+      return iterator(chunks, chunks.begin(), 0);
     }
 
     auto end() const noexcept
@@ -272,7 +262,7 @@ inline namespace memory
     {
       if (auto iter = lower_bound_chunk(p); iter != chunks.end())
       {
-        return iterator(chunks, std::distance(chunks.begin(), iter), p.index());
+        return iterator(chunks, iter, p.index());
       }
       else
       {
diff --git a/include/meevax/utility/debug.hpp b/include/meevax/utility/debug.hpp
index 623b23cd8..5ebdf551a 100644
--- a/include/meevax/utility/debug.hpp
+++ b/include/meevax/utility/debug.hpp
@@ -21,9 +21,9 @@
 #include <iostream>
 
 #define LINE() \
-  std::cout << "; \x1b[33m" __FILE__ "\x1b[31m:\x1b[36m" << __LINE__ << "\x1b[0m" << std::endl
+  std::cerr << "; \x1b[33m" __FILE__ "\x1b[31m:\x1b[36m" << __LINE__ << "\x1b[0m" << std::endl
 
 #define PRINT(...) \
-  std::cout << "; " #__VA_ARGS__ " = " << std::boolalpha << (__VA_ARGS__) << std::endl
+  std::cerr << "; " #__VA_ARGS__ " = " << std::boolalpha << (__VA_ARGS__) << std::endl
 
 #endif // INCLUDED_MEEVAX_UTILITY_DEBUG_HPP
diff --git a/src/memory/collector.cpp b/src/memory/collector.cpp
index 42ac7ec10..2416d0637 100644
--- a/src/memory/collector.cpp
+++ b/src/memory/collector.cpp
@@ -66,7 +66,7 @@ inline namespace memory
   {
     marker::clear();
 
-    auto is_root_object = [begin = std::begin(headers)](registration * given)
+    auto is_root_object = [begin = headers.begin()](registration * given)
     {
       /*
          If the given registration is a non-root object, then an object
@@ -106,7 +106,7 @@ inline namespace memory
       const auto lower_address = reinterpret_cast<registration *>(header->lower_address());
       const auto upper_address = reinterpret_cast<registration *>(header->upper_address());
 
-      for (auto iter = registry.lower_bound(lower_address); iter != std::end(registry) and *iter < upper_address; ++iter)
+      for (auto iter = registry.lower_bound(lower_address); iter != registry.end() and *iter < upper_address; ++iter)
       {
         mark((*iter)->header);
       }

From 00ea63e594916ed9726c9a7703d15fc49b7f034b Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Thu, 12 Oct 2023 01:25:58 +0900
Subject: [PATCH 04/31] Update procedure `xcons` to built-in

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md           |  6 +++---
 VERSION             |  2 +-
 basis/srfi-1.ss     | 17 +++++------------
 src/kernel/boot.cpp |  5 +++++
 4 files changed, 14 insertions(+), 16 deletions(-)

diff --git a/README.md b/README.md
index 76435467a..6872ab730 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.35_amd64.deb
+sudo apt install build/meevax_0.5.36_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.35.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.36.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.35_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.36_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index 0defa4dc0..cf59382c9 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.35
+0.5.36
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index d5d71bc1a..2834599c6 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -7,7 +7,10 @@
 |#
 
 (define-library (srfi 1)
-  (import (scheme base)
+  (import (only (meevax pair)
+                xcons
+                )
+          (scheme base)
           (scheme cxr)
           (srfi 8))
 
@@ -32,17 +35,7 @@
           lset-xor lset-xor! lset-diff+intersection lset-diff+intersection!
           set-car! set-cdr!)
 
-  (begin (define (xcons x y)
-           (cons y x))
-
-         (define (tree-copy x)
-           (letrec ((tree-copy (lambda (x)
-                                 (if (not (pair? x)) x
-                                     (cons (tree-copy (car x))
-                                           (tree-copy (cdr x)))))))
-             (tree-copy x)))
-
-         (define (list-tabulate len proc)
+  (begin (define (list-tabulate len proc)
            (do ((i (- len 1) (- i 1))
                 (ans '() (cons (proc i) ans)))
              ((< i 0) ans)))
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index 9c1f08869..1474e32ce 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -889,6 +889,11 @@ inline namespace kernel
         return cons(xs[0], xs[1]);
       });
 
+      library.define<procedure>("xcons", [](let const& xs)
+      {
+        return cons(xs[1], xs[0]);
+      });
+
       library.define<procedure>("car", [](let const& xs) -> auto const& { return car(xs[0]); });
       library.define<procedure>("cdr", [](let const& xs) -> auto const& { return cdr(xs[0]); });
 

From 02990bef5332b070756bb00c042584ad60c09506 Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Thu, 12 Oct 2023 01:52:22 +0900
Subject: [PATCH 05/31] Update procedure `last` and `last-pair` to built-in

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md                             |  6 +++---
 VERSION                               |  2 +-
 basis/srfi-1.ss                       | 11 ++++-------
 include/meevax/kernel/list.hpp        |  6 ++++++
 include/meevax/memory/pointer_set.hpp |  1 +
 src/kernel/boot.cpp                   | 10 ++++++++++
 6 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/README.md b/README.md
index 6872ab730..4abc13190 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.36_amd64.deb
+sudo apt install build/meevax_0.5.37_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.36.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.37.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.36_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.37_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index cf59382c9..6466a623e 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.36
+0.5.37
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index 2834599c6..71b023353 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -10,6 +10,10 @@
   (import (only (meevax pair)
                 xcons
                 )
+          (only (meevax list)
+                last
+                last-pair
+                )
           (scheme base)
           (scheme cxr)
           (srfi 8))
@@ -207,13 +211,6 @@
                  (set-cdr! prev '())
                  (values x suffix))))
 
-         (define (last x) (car (last-pair x)))
-
-         (define (last-pair lis)
-           (let rec ((lis lis))
-             (let ((tail (cdr lis)))
-               (if (pair? tail) (rec tail) lis))))
-
          (define (length+ x) ; Returns #f if X is circular.
            (let rec ((x x) (lag x) (len 0))
              (if (pair? x)
diff --git a/include/meevax/kernel/list.hpp b/include/meevax/kernel/list.hpp
index 3b8b6c0cd..e519645bc 100644
--- a/include/meevax/kernel/list.hpp
+++ b/include/meevax/kernel/list.hpp
@@ -121,6 +121,12 @@ inline namespace kernel
 
   auto last(object const&) -> object const&;
 
+  template <typename T>
+  auto last_pair(T&& x) -> decltype(x)
+  {
+    return cdr(x).template is<pair>() ? last_pair(cdr(x)) : x;
+  }
+
   auto take(object const&, std::size_t) -> object;
 
   auto length(object const&) -> std::size_t;
diff --git a/include/meevax/memory/pointer_set.hpp b/include/meevax/memory/pointer_set.hpp
index 26468e057..ee88d719f 100644
--- a/include/meevax/memory/pointer_set.hpp
+++ b/include/meevax/memory/pointer_set.hpp
@@ -18,6 +18,7 @@
 #define INCLUDED_MEEVAX_MEMORY_POINTER_SET_HPP
 
 #include <algorithm>
+#include <array>
 #include <cassert>
 #include <cstdint>
 #include <iterator>
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index 1474e32ce..3dc4c5bf3 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -561,6 +561,16 @@ inline namespace kernel
         return make_list(xs[0].as<exact_integer>(), 1 < length(xs) ? xs[1] : f);
       });
 
+      library.define<procedure>("last", [](let const& xs) -> auto const&
+      {
+        return last(xs[0]);
+      });
+
+      library.define<procedure>("last-pair", [](let const& xs) -> auto const&
+      {
+        return last_pair(xs[0]);
+      });
+
       library.define<procedure>("length", [](let const& xs)
       {
         return make<exact_integer>(length(xs[0]));

From 74ea30ff8c7a394f4b0f4963e2071086ea5704f5 Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Thu, 12 Oct 2023 20:37:33 +0900
Subject: [PATCH 06/31] Update procedure `circular-list?` and `circular-list`
 to built-in

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md                      |  6 ++---
 VERSION                        |  2 +-
 basis/srfi-1.ss                | 25 ++++++-------------
 include/meevax/kernel/list.hpp | 45 ++++++++++++++++++++++------------
 src/kernel/boot.cpp            | 23 ++++++++++++++++-
 src/kernel/list.cpp            | 26 ++++++++++++++++++--
 src/kernel/pair.cpp            | 15 +-----------
 test/collector.cpp             | 12 ---------
 test/srfi-1.ss                 | 36 +++++++++++++++++++++++++++
 9 files changed, 124 insertions(+), 66 deletions(-)
 create mode 100644 test/srfi-1.ss

diff --git a/README.md b/README.md
index 4abc13190..953e5273f 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.37_amd64.deb
+sudo apt install build/meevax_0.5.38_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.37.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.38.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.37_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.38_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index 6466a623e..db9b6e49f 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.37
+0.5.38
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index 71b023353..d06a3e175 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -9,13 +9,20 @@
 (define-library (srfi 1)
   (import (only (meevax pair)
                 xcons
+                caaar caadr cadar caddr
+                cdaar cdadr cddar cdddr
+                caaaar caaadr caadar caaddr
+                cadaar cadadr caddar cadddr
+                cdaaar cdaadr cdadar cdaddr
+                cddaar cddadr cdddar cddddr
                 )
           (only (meevax list)
+                circular-list
+                circular-list?
                 last
                 last-pair
                 )
           (scheme base)
-          (scheme cxr)
           (srfi 8))
 
   (export cons list xcons cons* make-list list-tabulate list-copy circular-list
@@ -52,11 +59,6 @@
                                 (cdr xs)))
                  x)))
 
-         (define (circular-list val1 . vals)
-           (let ((ans (cons val1 vals)))
-             (set-cdr! (last-pair ans) ans)
-             ans))
-
          (define (iota count . maybe-start+step)
            (if (< count 0) (error "Negative step count" iota count))
            (let-optionals maybe-start+step ((start 0) (step 1))
@@ -79,17 +81,6 @@
                        (not (null? x))))
                  (not (null? x)))))
 
-         (define (circular-list? x)
-           (let rec ((x x)
-                     (y x))
-             (and (pair? x)
-                  (let ((x (cdr x)))
-                    (and (pair? x)
-                         (let ((x (cdr x))
-                               (y (cdr y)))
-                           (or (eq? x y)
-                               (rec x y))))))))
-
          (define (not-pair? x) (not (pair? x)))
 
          (define (null-list? x)
diff --git a/include/meevax/kernel/list.hpp b/include/meevax/kernel/list.hpp
index e519645bc..a68cafc1d 100644
--- a/include/meevax/kernel/list.hpp
+++ b/include/meevax/kernel/list.hpp
@@ -105,26 +105,46 @@ inline namespace kernel
 
   auto make_list(std::size_t, object const& = unit) -> object;
 
-  auto is_list(object const&) -> bool;
+  template <typename T>
+  auto last_pair(T&& x) -> decltype(x)
+  {
+    return cdr(x).template is<pair>() ? last_pair(cdr(std::forward<decltype(x)>(x))) : std::forward<decltype(x)>(x);
+  }
 
   template <typename T>
-  auto tail(T&& x, std::size_t size) -> decltype(x)
+  auto last(T&& x) -> decltype(x)
   {
-    return 0 < size ? tail(cdr(std::forward<decltype(x)>(x)), --size) : x;
+    return car(last_pair(std::forward<decltype(x)>(x)));
+  }
+
+  template <typename T>
+  auto circulate(T&& x)
+  {
+    cdr(last_pair(x)) = x;
   }
 
   template <typename... Ts>
-  auto head(Ts&&... xs) -> decltype(auto)
+  auto circular_list(Ts&&... xs)
   {
-    return car(tail(std::forward<decltype(xs)>(xs)...));
+    let x = list(std::forward<decltype(xs)>(xs)...);
+    circulate(x);
+    return x;
   }
 
-  auto last(object const&) -> object const&;
+  auto is_list(object const&) -> bool;
+
+  auto is_circular_list(object const&) -> bool;
 
   template <typename T>
-  auto last_pair(T&& x) -> decltype(x)
+  auto tail(T&& x, std::size_t size) -> decltype(x)
   {
-    return cdr(x).template is<pair>() ? last_pair(cdr(x)) : x;
+    return 0 < size ? tail(cdr(std::forward<decltype(x)>(x)), --size) : std::forward<decltype(x)>(x);
+  }
+
+  template <typename... Ts>
+  auto head(Ts&&... xs) -> decltype(auto)
+  {
+    return car(tail(std::forward<decltype(xs)>(xs)...));
   }
 
   auto take(object const&, std::size_t) -> object;
@@ -138,14 +158,7 @@ inline namespace kernel
   template <typename F>
   auto map(F f, object const& xs) -> object
   {
-    if (xs.is<pair>())
-    {
-      return cons(f(car(xs)), map(f, cdr(xs)));
-    }
-    else
-    {
-      return unit;
-    }
+    return xs.is<pair>() ? cons(f(car(xs)), map(f, cdr(xs))) : unit;
   }
 
   auto memq(object const&, object const&) -> object const&;
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index 3dc4c5bf3..6165b24eb 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -558,7 +558,28 @@ inline namespace kernel
 
       library.define<procedure>("make-list", [](let const& xs)
       {
-        return make_list(xs[0].as<exact_integer>(), 1 < length(xs) ? xs[1] : f);
+        switch (length(xs))
+        {
+        case 1:
+          return make_list(xs[0].as<exact_integer>());
+
+        case 2:
+          return make_list(xs[0].as<exact_integer>(), xs[1]);
+
+        default:
+          throw error(make<string>("procedure make-list takes one or two arugments, but got"), xs);
+        }
+      });
+
+      library.define<procedure>("circular-list?", [](let const& xs)
+      {
+        return is_circular_list(xs[0]);
+      });
+
+      library.define<procedure>("circular-list", [](let & xs)
+      {
+        circulate(xs);
+        return xs;
       });
 
       library.define<procedure>("last", [](let const& xs) -> auto const&
diff --git a/src/kernel/list.cpp b/src/kernel/list.cpp
index 174c8cc08..5733f866b 100644
--- a/src/kernel/list.cpp
+++ b/src/kernel/list.cpp
@@ -53,9 +53,31 @@ inline namespace kernel
     return is_list(xs, xs);
   }
 
-  auto last(object const& xs) -> object const&
+  auto is_circular_list(object const& x0, object const& y0) -> bool
   {
-    return cdr(xs).is<pair>() ? last(cdr(xs)) : car(xs);
+    if (x0.is<pair>())
+    {
+      if (let const& x1 = cdr(x0); x1.is<pair>())
+      {
+        let const& x2 = cdr(x1),
+                   y1 = cdr(y0);
+
+        return eq(x2, y1) or is_circular_list(x2, y1);
+      }
+      else
+      {
+        return false;
+      }
+    }
+    else
+    {
+      return false;
+    }
+  }
+
+  auto is_circular_list(object const& xs) -> bool
+  {
+    return is_circular_list(xs, xs);
   }
 
   auto take(object const& x, std::size_t size) -> object
diff --git a/src/kernel/pair.cpp b/src/kernel/pair.cpp
index 79227c57b..7ca61c493 100644
--- a/src/kernel/pair.cpp
+++ b/src/kernel/pair.cpp
@@ -48,20 +48,7 @@ inline namespace kernel
 
   auto operator <<(std::ostream & os, pair const& datum) -> std::ostream &
   {
-    auto is_circular_list = [&]()
-    {
-      for (auto rest = datum.second.get(); rest; rest = rest->second.get())
-      {
-        if (rest == &datum)
-        {
-          return true;
-        }
-      }
-
-      return false;
-    };
-
-    if (is_circular_list())
+    if (is_circular_list(cdr(datum)))
     {
       auto n = reinterpret_cast<std::uintptr_t>(&datum);
 
diff --git a/test/collector.cpp b/test/collector.cpp
index 928ee9314..18c1dfca2 100644
--- a/test/collector.cpp
+++ b/test/collector.cpp
@@ -139,18 +139,6 @@ auto main() -> int
 
       assert(gc.count() == gc_count + 3);
 
-      auto circular_list = [](auto&&... xs)
-      {
-        let x = list(std::forward<decltype(xs)>(xs)...);
-
-        if (auto const length = std::distance(std::cbegin(x), std::cend(x)); 0 < length)
-        {
-          cdr(std::next(std::begin(x), length - 1)) = x;
-        }
-
-        return x;
-      };
-
       return circular_list(a, b, c);
     };
 
diff --git a/test/srfi-1.ss b/test/srfi-1.ss
new file mode 100644
index 000000000..541cb5253
--- /dev/null
+++ b/test/srfi-1.ss
@@ -0,0 +1,36 @@
+(import (scheme base)
+        (scheme process-context)
+        (only (srfi 1)
+              xcons
+              circular-list
+              circular-list?
+              last
+              last-pair
+              )
+        (srfi 78))
+
+(check (cons 'a 'b) => '(a . b))
+
+(check (list 1 2 3) => '(1 2 3))
+
+(check (xcons 'a 'b) => '(b . a))
+
+(check (circular-list 1) => '#1=(1 . #1#))
+(check (circular-list 1 2) => '#1=(1 2 . #1#))
+(check (circular-list 1 2 3) => '#1=(1 2 3 . #1#))
+
+(check (circular-list? '(1 2 3)) => #f)
+(check (circular-list? '#1=(1 2 3 . #1#)) => #t)
+
+(check (last '(a)) => 'a)
+(check (last '(a b)) => 'b)
+(check (last '(a b c)) => 'c)
+
+(check (last-pair '(a)) => '(a))
+(check (last-pair '(a b)) => '(b))
+(check (last-pair '(a b c)) => '(c))
+(check (last-pair '(a b c . d)) => '(c . d))
+
+(check-report)
+
+(exit (check-passed? 15))

From df6d4987df4d66ad4866ab50c93db1f7cc8ea9d5 Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Thu, 12 Oct 2023 23:33:56 +0900
Subject: [PATCH 07/31] Update procedures `first`, `second`... `tenth` to
 built-in

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md           |  6 +++---
 VERSION             |  2 +-
 basis/srfi-1.ss     | 27 +-----------------------
 src/kernel/boot.cpp | 50 +++++++++++++++++++++++++++++++++++++++++++++
 test/srfi-1.ss      | 14 ++++++++++++-
 5 files changed, 68 insertions(+), 31 deletions(-)

diff --git a/README.md b/README.md
index 953e5273f..20dc08d49 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.38_amd64.deb
+sudo apt install build/meevax_0.5.39_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.38.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.39.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.38_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.39_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index db9b6e49f..c8e4e1e11 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.38
+0.5.39
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index d06a3e175..1d530aa3f 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -19,6 +19,7 @@
           (only (meevax list)
                 circular-list
                 circular-list?
+                first second third fourth fifth sixth seventh eighth ninth tenth
                 last
                 last-pair
                 )
@@ -108,32 +109,6 @@
                                       (lp2 (cdr pair-a)
                                            (cdr pair-b)))))))))))
 
-         (define first car)
-
-         (define second cadr)
-
-         (define third caddr)
-
-         (define fourth cadddr)
-
-         (define (fifth x)
-           (car (cddddr x)))
-
-         (define (sixth x)
-           (cadr (cddddr x)))
-
-         (define (seventh x)
-           (caddr (cddddr x)))
-
-         (define (eighth x)
-           (cadddr (cddddr x)))
-
-         (define (ninth x)
-           (car (cddddr (cddddr x))))
-
-         (define (tenth x)
-           (cadr (cddddr (cddddr x))))
-
          (define (car+cdr pair)
            (values (car pair)
                    (cdr pair)))
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index 6165b24eb..12137bc09 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -617,6 +617,56 @@ inline namespace kernel
         return xs[0][xs[1].as<exact_integer>()];
       });
 
+      library.define<procedure>("first", [](let const& xs) -> decltype(auto)
+      {
+        return xs[0][0];
+      });
+
+      library.define<procedure>("second", [](let const& xs) -> decltype(auto)
+      {
+        return xs[0][1];
+      });
+
+      library.define<procedure>("third", [](let const& xs) -> decltype(auto)
+      {
+        return xs[0][2];
+      });
+
+      library.define<procedure>("fourth", [](let const& xs) -> decltype(auto)
+      {
+        return xs[0][3];
+      });
+
+      library.define<procedure>("fifth", [](let const& xs) -> decltype(auto)
+      {
+        return xs[0][4];
+      });
+
+      library.define<procedure>("sixth", [](let const& xs) -> decltype(auto)
+      {
+        return xs[0][5];
+      });
+
+      library.define<procedure>("seventh", [](let const& xs) -> decltype(auto)
+      {
+        return xs[0][6];
+      });
+
+      library.define<procedure>("eighth", [](let const& xs) -> decltype(auto)
+      {
+        return xs[0][7];
+      });
+
+      library.define<procedure>("ninth", [](let const& xs) -> decltype(auto)
+      {
+        return xs[0][8];
+      });
+
+      library.define<procedure>("tenth", [](let const& xs) -> decltype(auto)
+      {
+        return xs[0][9];
+      });
+
       library.define<procedure>("memq", [](let const& xs) -> auto const&
       {
         return memq(xs[0], xs[1]);
diff --git a/test/srfi-1.ss b/test/srfi-1.ss
index 541cb5253..e9f360fab 100644
--- a/test/srfi-1.ss
+++ b/test/srfi-1.ss
@@ -4,6 +4,7 @@
               xcons
               circular-list
               circular-list?
+              first second third fourth fifth sixth seventh eighth ninth tenth
               last
               last-pair
               )
@@ -22,6 +23,17 @@
 (check (circular-list? '(1 2 3)) => #f)
 (check (circular-list? '#1=(1 2 3 . #1#)) => #t)
 
+(check (first   '(a b c d e f g h i j)) => 'a)
+(check (second  '(a b c d e f g h i j)) => 'b)
+(check (third   '(a b c d e f g h i j)) => 'c)
+(check (fourth  '(a b c d e f g h i j)) => 'd)
+(check (fifth   '(a b c d e f g h i j)) => 'e)
+(check (sixth   '(a b c d e f g h i j)) => 'f)
+(check (seventh '(a b c d e f g h i j)) => 'g)
+(check (eighth  '(a b c d e f g h i j)) => 'h)
+(check (ninth   '(a b c d e f g h i j)) => 'i)
+(check (tenth   '(a b c d e f g h i j)) => 'j)
+
 (check (last '(a)) => 'a)
 (check (last '(a b)) => 'b)
 (check (last '(a b c)) => 'c)
@@ -33,4 +45,4 @@
 
 (check-report)
 
-(exit (check-passed? 15))
+(exit (check-passed? 25))

From 13abe47e4e1cbccfdf0d358707a925da9c945ec1 Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Sat, 14 Oct 2023 00:40:37 +0900
Subject: [PATCH 08/31] Update procedure `dotted-list?` to built-in

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md                      |  6 +++---
 VERSION                        |  2 +-
 basis/srfi-1.ss                | 12 +-----------
 include/meevax/kernel/list.hpp |  2 ++
 src/kernel/boot.cpp            |  5 +++++
 src/kernel/list.cpp            | 27 +++++++++++++++++++++++++++
 test/srfi-1.ss                 |  7 ++++++-
 7 files changed, 45 insertions(+), 16 deletions(-)

diff --git a/README.md b/README.md
index 20dc08d49..4737d0f59 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.39_amd64.deb
+sudo apt install build/meevax_0.5.40_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.39.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.40.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.39_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.40_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index c8e4e1e11..f60ca0ff3 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.39
+0.5.40
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index 1d530aa3f..c5e7a964a 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -19,6 +19,7 @@
           (only (meevax list)
                 circular-list
                 circular-list?
+                dotted-list?
                 first second third fourth fifth sixth seventh eighth ninth tenth
                 last
                 last-pair
@@ -71,17 +72,6 @@
 
          (define proper-list? list?)
 
-         (define (dotted-list? x)
-           (let rec ((x x) (lag x))
-             (if (pair? x)
-                 (let ((x (cdr x)))
-                   (if (pair? x)
-                       (let ((x   (cdr x))
-                             (lag (cdr lag)))
-                         (and (not (eq? x lag)) (rec x lag)))
-                       (not (null? x))))
-                 (not (null? x)))))
-
          (define (not-pair? x) (not (pair? x)))
 
          (define (null-list? x)
diff --git a/include/meevax/kernel/list.hpp b/include/meevax/kernel/list.hpp
index a68cafc1d..c7d4ac3cf 100644
--- a/include/meevax/kernel/list.hpp
+++ b/include/meevax/kernel/list.hpp
@@ -135,6 +135,8 @@ inline namespace kernel
 
   auto is_circular_list(object const&) -> bool;
 
+  auto is_dotted_list(object const&) -> bool;
+
   template <typename T>
   auto tail(T&& x, std::size_t size) -> decltype(x)
   {
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index 12137bc09..cac060529 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -582,6 +582,11 @@ inline namespace kernel
         return xs;
       });
 
+      library.define<procedure>("dotted-list?", [](let const& xs)
+      {
+        return is_dotted_list(xs[0]);
+      });
+
       library.define<procedure>("last", [](let const& xs) -> auto const&
       {
         return last(xs[0]);
diff --git a/src/kernel/list.cpp b/src/kernel/list.cpp
index 5733f866b..a2e799795 100644
--- a/src/kernel/list.cpp
+++ b/src/kernel/list.cpp
@@ -80,6 +80,33 @@ inline namespace kernel
     return is_circular_list(xs, xs);
   }
 
+  auto is_dotted_list(object const& x0, object const& y0) -> bool
+  {
+    if (x0.is<pair>())
+    {
+      if (let const& x1 = cdr(x0); x1.is<pair>())
+      {
+        let const& x2 = cdr(x1),
+                   y1 = cdr(y0);
+
+        return not eq(x2, y1) and is_dotted_list(x2, y1);
+      }
+      else
+      {
+        return not x1.is<null>();
+      }
+    }
+    else
+    {
+      return not x0.is<null>();
+    }
+  }
+
+  auto is_dotted_list(object const& xs) -> bool
+  {
+    return is_dotted_list(xs, xs);
+  }
+
   auto take(object const& x, std::size_t size) -> object
   {
     return 0 < size ? cons(car(x), take(cdr(x), --size)) : unit;
diff --git a/test/srfi-1.ss b/test/srfi-1.ss
index e9f360fab..aaf21c317 100644
--- a/test/srfi-1.ss
+++ b/test/srfi-1.ss
@@ -4,6 +4,7 @@
               xcons
               circular-list
               circular-list?
+              dotted-list?
               first second third fourth fifth sixth seventh eighth ninth tenth
               last
               last-pair
@@ -23,6 +24,10 @@
 (check (circular-list? '(1 2 3)) => #f)
 (check (circular-list? '#1=(1 2 3 . #1#)) => #t)
 
+(check (dotted-list? '(1 . 2)) => #t)
+(check (dotted-list? '(1 2 . 3)) => #t)
+(check (dotted-list? '(1 2 3)) => #f)
+
 (check (first   '(a b c d e f g h i j)) => 'a)
 (check (second  '(a b c d e f g h i j)) => 'b)
 (check (third   '(a b c d e f g h i j)) => 'c)
@@ -45,4 +50,4 @@
 
 (check-report)
 
-(exit (check-passed? 25))
+(exit (check-passed? 28))

From 80f4bb14e4d7e8f833595d22daccc1de54178bd4 Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Sat, 14 Oct 2023 00:45:04 +0900
Subject: [PATCH 09/31] Update procedure `not-pair?` to built-in

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md           | 6 +++---
 VERSION             | 2 +-
 basis/srfi-1.ss     | 3 +--
 src/kernel/boot.cpp | 5 +++++
 test/srfi-1.ss      | 8 +++++++-
 5 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/README.md b/README.md
index 4737d0f59..c7926a1d2 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.40_amd64.deb
+sudo apt install build/meevax_0.5.41_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.40.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.41.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.40_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.41_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index f60ca0ff3..6a2954dab 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.40
+0.5.41
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index c5e7a964a..c70251d0a 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -8,6 +8,7 @@
 
 (define-library (srfi 1)
   (import (only (meevax pair)
+                not-pair?
                 xcons
                 caaar caadr cadar caddr
                 cdaar cdadr cddar cdddr
@@ -72,8 +73,6 @@
 
          (define proper-list? list?)
 
-         (define (not-pair? x) (not (pair? x)))
-
          (define (null-list? x)
            (cond ((pair? x) #f)
                  ((null? x) #t)
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index cac060529..9ccdbe193 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -970,6 +970,11 @@ inline namespace kernel
         return xs[0].is<pair>();
       });
 
+      library.define<procedure>("not-pair?", [](let const& xs)
+      {
+        return not xs[0].is<pair>();
+      });
+
       library.define<procedure>("cons", [](let const& xs)
       {
         return cons(xs[0], xs[1]);
diff --git a/test/srfi-1.ss b/test/srfi-1.ss
index aaf21c317..b282018c1 100644
--- a/test/srfi-1.ss
+++ b/test/srfi-1.ss
@@ -5,6 +5,7 @@
               circular-list
               circular-list?
               dotted-list?
+              not-pair?
               first second third fourth fifth sixth seventh eighth ninth tenth
               last
               last-pair
@@ -28,6 +29,11 @@
 (check (dotted-list? '(1 2 . 3)) => #t)
 (check (dotted-list? '(1 2 3)) => #f)
 
+(check (not-pair? 42) => #t)
+(check (not-pair? '(a . b)) => #f)
+(check (not-pair? '(a b . c)) => #f)
+(check (not-pair? '(a b c)) => #f)
+
 (check (first   '(a b c d e f g h i j)) => 'a)
 (check (second  '(a b c d e f g h i j)) => 'b)
 (check (third   '(a b c d e f g h i j)) => 'c)
@@ -50,4 +56,4 @@
 
 (check-report)
 
-(exit (check-passed? 28))
+(exit (check-passed? 32))

From 66dce30f440c5e2ddfd8013cfbb3384a04ac50de Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Sat, 14 Oct 2023 01:29:56 +0900
Subject: [PATCH 10/31] Update procedure `take` to built-in

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md           |  6 +++---
 VERSION             |  2 +-
 basis/srfi-1.ss     | 50 ++++++++++++++++++++++++---------------------
 src/kernel/boot.cpp |  5 +++++
 test/srfi-1.ss      | 32 ++++++++++++++++++++---------
 5 files changed, 58 insertions(+), 37 deletions(-)

diff --git a/README.md b/README.md
index c7926a1d2..5cce767ef 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.41_amd64.deb
+sudo apt install build/meevax_0.5.42_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.41.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.42.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.41_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.42_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index 6a2954dab..46c41a019 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.41
+0.5.42
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index c70251d0a..dcce70094 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -8,24 +8,43 @@
 
 (define-library (srfi 1)
   (import (only (meevax pair)
-                not-pair?
+                cons
                 xcons
-                caaar caadr cadar caddr
-                cdaar cdadr cddar cdddr
-                caaaar caaadr caadar caaddr
-                cadaar cadadr caddar cadddr
-                cdaaar cdaadr cdadar cdaddr
-                cddaar cddadr cdddar cddddr
+                pair?
+                not-pair?
+                car cdr caar cadr cdar cddr caaar caadr cadar caddr cdaar cdadr cddar cdddr caaaar caaadr caadar caaddr cadaar cadadr caddar cadddr cdaaar cdaadr cdadar cdaddr cddaar cddadr cdddar cddddr
                 )
           (only (meevax list)
+                list
+                ; const*
+                make-list
+                ; list-tabulate
+                ; list-copy
                 circular-list
+                ; iota
+                ; null?
+                ; proper-list?
                 circular-list?
                 dotted-list?
+                ; null-list?
+                ; list=
+                list-ref
                 first second third fourth fifth sixth seventh eighth ninth tenth
+                ; car+cdr
+                take
+
                 last
                 last-pair
                 )
-          (scheme base)
+          (except (scheme base)
+                  cons
+                  list
+                  make-list
+                  pair?
+                  null?
+                  car cdr caar cadr cdar cddr
+                  list-ref
+                  )
           (srfi 8))
 
   (export cons list xcons cons* make-list list-tabulate list-copy circular-list
@@ -102,13 +121,6 @@
            (values (car pair)
                    (cdr pair)))
 
-         (define (take x k)
-           (let rec ((x x)
-                     (k k))
-             (if (zero? k) '()
-                 (cons (car x)
-                       (rec (cdr x) (- k 1))))))
-
          (define (take! x k)
            (if (zero? k)
                (begin (set-cdr! (drop x (- k 1)) '()) x)))
@@ -118,14 +130,6 @@
              (if (zero? k) x
                  (rec (cdr x) (- k 1)))))
 
-         (define (drop! lis k)
-           (if (negative? k)
-               (let ((nelts (+ k (length lis))))
-                 (if (zero? nelts) '()
-                     (begin (set-cdr! (list-tail lis (- nelts 1)) '())
-                            lis)))
-               (list-tail lis k)))
-
          (define (take-right x k)
            (let lp ((lag x)
                     (lead (drop x k)))
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index 9ccdbe193..403099b0f 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -672,6 +672,11 @@ inline namespace kernel
         return xs[0][9];
       });
 
+      library.define<procedure>("take", [](let const& xs)
+      {
+        return take(xs[0], xs[1].as<exact_integer>());
+      });
+
       library.define<procedure>("memq", [](let const& xs) -> auto const&
       {
         return memq(xs[0], xs[1]);
diff --git a/test/srfi-1.ss b/test/srfi-1.ss
index b282018c1..b84099ae1 100644
--- a/test/srfi-1.ss
+++ b/test/srfi-1.ss
@@ -7,27 +7,29 @@
               dotted-list?
               not-pair?
               first second third fourth fifth sixth seventh eighth ninth tenth
+              take
               last
               last-pair
+              length+
               )
         (srfi 78))
 
 (check (cons 'a 'b) => '(a . b))
 
-(check (list 1 2 3) => '(1 2 3))
+(check (list 'a 'b 'c) => '(a b c))
 
 (check (xcons 'a 'b) => '(b . a))
 
-(check (circular-list 1) => '#1=(1 . #1#))
-(check (circular-list 1 2) => '#1=(1 2 . #1#))
-(check (circular-list 1 2 3) => '#1=(1 2 3 . #1#))
+(check (circular-list 'a) => '#1=(a . #1#))
+(check (circular-list 'a 'b) => '#1=(a b . #1#))
+(check (circular-list 'a 'b 'c) => '#1=(a b c . #1#))
 
-(check (circular-list? '(1 2 3)) => #f)
-(check (circular-list? '#1=(1 2 3 . #1#)) => #t)
+(check (circular-list? '(a b c)) => #f)
+(check (circular-list? '#1=(a b c . #1#)) => #t)
 
-(check (dotted-list? '(1 . 2)) => #t)
-(check (dotted-list? '(1 2 . 3)) => #t)
-(check (dotted-list? '(1 2 3)) => #f)
+(check (dotted-list? '(a . b)) => #t)
+(check (dotted-list? '(a b . c)) => #t)
+(check (dotted-list? '(a b c)) => #f)
 
 (check (not-pair? 42) => #t)
 (check (not-pair? '(a . b)) => #f)
@@ -45,6 +47,12 @@
 (check (ninth   '(a b c d e f g h i j)) => 'i)
 (check (tenth   '(a b c d e f g h i j)) => 'j)
 
+(check (take '(a b c d e) 1) => '(a))
+(check (take '(a b c d e) 2) => '(a b))
+(check (take '(a b c d e) 3) => '(a b c))
+(check (take '(a b c d e) 4) => '(a b c d))
+(check (take '(a b c d e) 5) => '(a b c d e))
+
 (check (last '(a)) => 'a)
 (check (last '(a b)) => 'b)
 (check (last '(a b c)) => 'c)
@@ -54,6 +62,10 @@
 (check (last-pair '(a b c)) => '(c))
 (check (last-pair '(a b c . d)) => '(c . d))
 
+(check (length+ '(a b c)) => 3)
+(check (length+ '(a b . c)) => 2)
+(check (length+ '#1=(a b c . #1#)) => #f)
+
 (check-report)
 
-(exit (check-passed? 32))
+(exit (check-passed? 40))

From 442c020ff459d7286decd823a0ab2163d148a60a Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Sat, 14 Oct 2023 17:48:58 +0900
Subject: [PATCH 11/31] Update procedure `cons*` to built-int

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md           |  6 +++---
 VERSION             |  2 +-
 basis/srfi-1.ss     | 12 ++----------
 src/kernel/boot.cpp | 25 +++++++++++++++++++++++++
 test/srfi-1.ss      |  9 +++++++--
 5 files changed, 38 insertions(+), 16 deletions(-)

diff --git a/README.md b/README.md
index 5cce767ef..41dfa3692 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.42_amd64.deb
+sudo apt install build/meevax_0.5.43_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.42.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.43.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.42_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.43_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index 46c41a019..43a6fbdb0 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.42
+0.5.43
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index dcce70094..77629d822 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -16,7 +16,7 @@
                 )
           (only (meevax list)
                 list
-                ; const*
+                cons*
                 make-list
                 ; list-tabulate
                 ; list-copy
@@ -71,15 +71,7 @@
   (begin (define (list-tabulate len proc)
            (do ((i (- len 1) (- i 1))
                 (ans '() (cons (proc i) ans)))
-             ((< i 0) ans)))
-
-         (define (cons* x . xs)
-           (let cons* ((x x)
-                       (xs xs))
-             (if (pair? xs)
-                 (cons x (cons* (car xs)
-                                (cdr xs)))
-                 x)))
+               ((< i 0) ans)))
 
          (define (iota count . maybe-start+step)
            (if (< count 0) (error "Negative step count" iota count))
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index 403099b0f..303702147 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -556,6 +556,31 @@ inline namespace kernel
         return xs;
       });
 
+      library.define<procedure>("cons*", [](let & xs)
+      {
+        if (xs.is<null>())
+        {
+          throw error(make<string>("procedure cons* takes at least one arugments, but got"), xs);
+        }
+        else if (cdr(xs).is<null>())
+        {
+          return xs[0];
+        }
+        else
+        {
+          auto node = xs.get();
+
+          while (not cddr(*node).is<null>())
+          {
+            node = cdr(*node).get();
+          }
+
+          cdr(*node) = cadr(*node);
+
+          return xs;
+        }
+      });
+
       library.define<procedure>("make-list", [](let const& xs)
       {
         switch (length(xs))
diff --git a/test/srfi-1.ss b/test/srfi-1.ss
index b84099ae1..d56ff5ea9 100644
--- a/test/srfi-1.ss
+++ b/test/srfi-1.ss
@@ -2,6 +2,7 @@
         (scheme process-context)
         (only (srfi 1)
               xcons
+              cons*
               circular-list
               circular-list?
               dotted-list?
@@ -20,6 +21,10 @@
 
 (check (xcons 'a 'b) => '(b . a))
 
+(check (cons* 'a) => 'a)
+(check (cons* 'a 'b) => '(a . b))
+(check (cons* 'a 'b 'c) => '(a b . c))
+
 (check (circular-list 'a) => '#1=(a . #1#))
 (check (circular-list 'a 'b) => '#1=(a b . #1#))
 (check (circular-list 'a 'b 'c) => '#1=(a b c . #1#))
@@ -31,7 +36,7 @@
 (check (dotted-list? '(a b . c)) => #t)
 (check (dotted-list? '(a b c)) => #f)
 
-(check (not-pair? 42) => #t)
+(check (not-pair? 'a) => #t)
 (check (not-pair? '(a . b)) => #f)
 (check (not-pair? '(a b . c)) => #f)
 (check (not-pair? '(a b c)) => #f)
@@ -68,4 +73,4 @@
 
 (check-report)
 
-(exit (check-passed? 40))
+(exit (check-passed? 43))

From 4c6da13a5d7156a80e904e3260fed9d2ff5d3914 Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Sat, 14 Oct 2023 18:30:59 +0900
Subject: [PATCH 12/31] Update procedure `iota` to built-in

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md                      |  6 +++---
 VERSION                        |  2 +-
 basis/srfi-1.ss                | 13 ++-----------
 include/meevax/kernel/list.hpp |  3 +++
 src/kernel/boot.cpp            | 18 ++++++++++++++++++
 src/kernel/list.cpp            |  5 +++++
 test/srfi-1.ss                 |  7 ++++++-
 7 files changed, 38 insertions(+), 16 deletions(-)

diff --git a/README.md b/README.md
index 41dfa3692..3bbe36b4e 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.43_amd64.deb
+sudo apt install build/meevax_0.5.44_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.43.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.44.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.43_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.44_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index 43a6fbdb0..b9689d467 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.43
+0.5.44
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index 77629d822..2e2dd4343 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -21,8 +21,8 @@
                 ; list-tabulate
                 ; list-copy
                 circular-list
-                ; iota
-                ; null?
+                iota
+                null?
                 ; proper-list?
                 circular-list?
                 dotted-list?
@@ -73,15 +73,6 @@
                 (ans '() (cons (proc i) ans)))
                ((< i 0) ans)))
 
-         (define (iota count . maybe-start+step)
-           (if (< count 0) (error "Negative step count" iota count))
-           (let-optionals maybe-start+step ((start 0) (step 1))
-             (let loop ((n 0) (r '()))
-               (if (= n count)
-                   (reverse r)
-                   (loop (+ 1 n)
-                         (cons (+ start (* n step)) r))))))
-
          (define proper-list? list?)
 
          (define (null-list? x)
diff --git a/include/meevax/kernel/list.hpp b/include/meevax/kernel/list.hpp
index c7d4ac3cf..0ba7e3bb0 100644
--- a/include/meevax/kernel/list.hpp
+++ b/include/meevax/kernel/list.hpp
@@ -18,6 +18,7 @@
 #define INCLUDED_MEEVAX_KERNEL_LIST_HPP
 
 #include <meevax/kernel/comparator.hpp>
+#include <meevax/kernel/number.hpp>
 
 namespace meevax
 {
@@ -105,6 +106,8 @@ inline namespace kernel
 
   auto make_list(std::size_t, object const& = unit) -> object;
 
+  auto iota(std::size_t, object const& = e0, object const& = e1) -> object;
+
   template <typename T>
   auto last_pair(T&& x) -> decltype(x)
   {
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index 303702147..4e62701d0 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -596,6 +596,24 @@ inline namespace kernel
         }
       });
 
+      library.define<procedure>("iota", [](let const& xs)
+      {
+        switch (length(xs))
+        {
+        case 1:
+          return iota(xs[0].as<exact_integer>());
+
+        case 2:
+          return iota(xs[0].as<exact_integer>(), xs[1]);
+
+        case 3:
+          return iota(xs[0].as<exact_integer>(), xs[1], xs[2]);
+
+        default:
+          throw error(make<string>("procedure iota takes one to three arugments, but got"), xs);
+        }
+      });
+
       library.define<procedure>("circular-list?", [](let const& xs)
       {
         return is_circular_list(xs[0]);
diff --git a/src/kernel/list.cpp b/src/kernel/list.cpp
index a2e799795..83ce248a2 100644
--- a/src/kernel/list.cpp
+++ b/src/kernel/list.cpp
@@ -26,6 +26,11 @@ inline namespace kernel
     return 0 < size ? cons(x, make_list(--size, x)) : unit;
   }
 
+  auto iota(std::size_t count, object const& start, object const& step) -> object
+  {
+    return 0 < count ? cons(start, iota(count - 1, start + step, step)) : unit;
+  }
+
   auto is_list(object const& x0, object const& y0) -> bool
   {
     if (x0.is<pair>())
diff --git a/test/srfi-1.ss b/test/srfi-1.ss
index d56ff5ea9..f31f4c499 100644
--- a/test/srfi-1.ss
+++ b/test/srfi-1.ss
@@ -4,9 +4,11 @@
               xcons
               cons*
               circular-list
+              iota
               circular-list?
               dotted-list?
               not-pair?
+              list=
               first second third fourth fifth sixth seventh eighth ninth tenth
               take
               last
@@ -29,6 +31,9 @@
 (check (circular-list 'a 'b) => '#1=(a b . #1#))
 (check (circular-list 'a 'b 'c) => '#1=(a b c . #1#))
 
+(check (iota 5) => '(0 1 2 3 4))
+(check (iota 5 0 -0.1) (=> (lambda (x y) (list= = x y))) '(0 -0.1 -0.2 -0.3 -0.4))
+
 (check (circular-list? '(a b c)) => #f)
 (check (circular-list? '#1=(a b c . #1#)) => #t)
 
@@ -73,4 +78,4 @@
 
 (check-report)
 
-(exit (check-passed? 43))
+(exit (check-passed? 45))

From 973f4898f69aa493bff5ece38742e0894ff1f67b Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Sat, 14 Oct 2023 18:48:15 +0900
Subject: [PATCH 13/31] Update procedure `null-list?` to built-in

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md           |  6 +++---
 VERSION             |  2 +-
 basis/srfi-1.ss     | 11 ++---------
 src/kernel/boot.cpp | 12 ++++++++++++
 test/srfi-1.ss      |  7 ++++++-
 5 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/README.md b/README.md
index 3bbe36b4e..4dd623065 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.44_amd64.deb
+sudo apt install build/meevax_0.5.45_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.44.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.45.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.44_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.45_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index b9689d467..9c271903a 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.44
+0.5.45
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index 2e2dd4343..c2a841680 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -15,9 +15,7 @@
                 car cdr caar cadr cdar cddr caaar caadr cadar caddr cdaar cdadr cddar cdddr caaaar caaadr caadar caaddr cadaar cadadr caddar cadddr cdaaar cdaadr cdadar cdaddr cddaar cddadr cdddar cddddr
                 )
           (only (meevax list)
-                list
-                cons*
-                make-list
+                list cons* make-list
                 ; list-tabulate
                 ; list-copy
                 circular-list
@@ -26,7 +24,7 @@
                 ; proper-list?
                 circular-list?
                 dotted-list?
-                ; null-list?
+                null-list?
                 ; list=
                 list-ref
                 first second third fourth fifth sixth seventh eighth ninth tenth
@@ -75,11 +73,6 @@
 
          (define proper-list? list?)
 
-         (define (null-list? x)
-           (cond ((pair? x) #f)
-                 ((null? x) #t)
-                 (else (error "argument out of domain" (list 'null-list? x)))))
-
          (define (list= = . lists)
            (or (null? lists) ; special case
                (let lp1 ((list-a (car lists))
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index 4e62701d0..1d6dc3469 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -630,6 +630,18 @@ inline namespace kernel
         return is_dotted_list(xs[0]);
       });
 
+      library.define<procedure>("null-list?", [](let const& xs)
+      {
+        if (is_list(xs[0]) or is_circular_list(xs[0]))
+        {
+          return xs[0].is<null>();
+        }
+        else
+        {
+          throw error(make<string>("procedure null-list? takes a proper-list or a circular-list, but got"), xs);
+        }
+      });
+
       library.define<procedure>("last", [](let const& xs) -> auto const&
       {
         return last(xs[0]);
diff --git a/test/srfi-1.ss b/test/srfi-1.ss
index f31f4c499..df6e0a747 100644
--- a/test/srfi-1.ss
+++ b/test/srfi-1.ss
@@ -8,6 +8,7 @@
               circular-list?
               dotted-list?
               not-pair?
+              null-list?
               list=
               first second third fourth fifth sixth seventh eighth ninth tenth
               take
@@ -46,6 +47,10 @@
 (check (not-pair? '(a b . c)) => #f)
 (check (not-pair? '(a b c)) => #f)
 
+(check (null-list? '()) => #t)
+(check (null-list? '(a b c)) => #f)
+(check (null-list? '#1=(a b c . #1#)) => #f)
+
 (check (first   '(a b c d e f g h i j)) => 'a)
 (check (second  '(a b c d e f g h i j)) => 'b)
 (check (third   '(a b c d e f g h i j)) => 'c)
@@ -78,4 +83,4 @@
 
 (check-report)
 
-(exit (check-passed? 45))
+(exit (check-passed? 48))

From 7514b065e3cb920f1e9b6cdd516ab35aa6021ef8 Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Sat, 14 Oct 2023 19:23:05 +0900
Subject: [PATCH 14/31] Update procedure `list-copy` to built-in

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md                      |  6 +++---
 VERSION                        |  2 +-
 basis/r7rs.ss                  |  9 +--------
 basis/srfi-1.ss                | 24 +++++++++---------------
 include/meevax/kernel/list.hpp |  2 ++
 src/kernel/boot.cpp            |  5 +++++
 src/kernel/list.cpp            |  5 +++++
 test/srfi-1.ss                 |  6 +++++-
 8 files changed, 31 insertions(+), 28 deletions(-)

diff --git a/README.md b/README.md
index 4dd623065..a5feb23dd 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.45_amd64.deb
+sudo apt install build/meevax_0.5.46_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.45.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.46.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.45_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.46_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index 9c271903a..bb49383f1 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.45
+0.5.46
diff --git a/basis/r7rs.ss b/basis/r7rs.ss
index 1738f4a7e..c9fd20029 100644
--- a/basis/r7rs.ss
+++ b/basis/r7rs.ss
@@ -2,7 +2,7 @@
   (import (only (meevax core) include include-case-insensitive)
           (only (meevax error) error-object? read-error? file-error?)
           (only (meevax macro-transformer) er-macro-transformer)
-          (only (meevax list) make-list)
+          (only (meevax list) make-list list-copy)
           (only (meevax number) exact-integer? exact-integer-square-root)
           (only (meevax port) binary-port? eof-object flush get-output-u8vector open-input-u8vector open-output-u8vector open? port? standard-error-port standard-input-port standard-output-port textual-port?)
           (prefix (meevax read) %)
@@ -191,13 +191,6 @@
          (define (list-set! xs k x)
            (set-car! (list-tail xs k) x))
 
-         (define (list-copy x)
-           (let list-copy ((x x))
-             (if (pair? x)
-                 (cons (car x)
-                       (list-copy (cdr x)))
-                 x)))
-
          (define symbol=? eqv?)
 
          (define bytevector? u8vector?)
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index c2a841680..91533ccb0 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -15,12 +15,7 @@
                 car cdr caar cadr cdar cddr caaar caadr cadar caddr cdaar cdadr cddar cdddr caaaar caaadr caadar caaddr cadaar cadadr caddar cadddr cdaaar cdaadr cdadar cdaddr cddaar cddadr cdddar cddddr
                 )
           (only (meevax list)
-                list cons* make-list
-                ; list-tabulate
-                ; list-copy
-                circular-list
-                iota
-                null?
+                list cons* make-list list-copy circular-list iota null?
                 ; proper-list?
                 circular-list?
                 dotted-list?
@@ -35,11 +30,7 @@
                 last-pair
                 )
           (except (scheme base)
-                  cons
-                  list
-                  make-list
-                  pair?
-                  null?
+                  cons list make-list list-copy pair? null?
                   car cdr caar cadr cdar cddr
                   list-ref
                   )
@@ -66,10 +57,13 @@
           lset-xor lset-xor! lset-diff+intersection lset-diff+intersection!
           set-car! set-cdr!)
 
-  (begin (define (list-tabulate len proc)
-           (do ((i (- len 1) (- i 1))
-                (ans '() (cons (proc i) ans)))
-               ((< i 0) ans)))
+  (begin (define (list-tabulate k f)
+           (letrec ((list-tabulate (lambda (i)
+                                     (if (< i k)
+                                         (cons (f i)
+                                               (list-tabulate (+ i 1)))
+                                         '()))))
+             (list-tabulate 0)))
 
          (define proper-list? list?)
 
diff --git a/include/meevax/kernel/list.hpp b/include/meevax/kernel/list.hpp
index 0ba7e3bb0..cd2a54efb 100644
--- a/include/meevax/kernel/list.hpp
+++ b/include/meevax/kernel/list.hpp
@@ -140,6 +140,8 @@ inline namespace kernel
 
   auto is_dotted_list(object const&) -> bool;
 
+  auto list_copy(object const&) -> object;
+
   template <typename T>
   auto tail(T&& x, std::size_t size) -> decltype(x)
   {
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index 1d6dc3469..74699e243 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -667,6 +667,11 @@ inline namespace kernel
         return reverse(xs[0]);
       });
 
+      library.define<procedure>("list-copy", [](let const& xs)
+      {
+        return list_copy(xs[0]);
+      });
+
       library.define<procedure>("list-tail", [](let const& xs) -> auto const&
       {
         return tail(xs[0], xs[1].as<exact_integer>());
diff --git a/src/kernel/list.cpp b/src/kernel/list.cpp
index 83ce248a2..a16c35980 100644
--- a/src/kernel/list.cpp
+++ b/src/kernel/list.cpp
@@ -112,6 +112,11 @@ inline namespace kernel
     return is_dotted_list(xs, xs);
   }
 
+  auto list_copy(object const& xs) -> object
+  {
+    return xs.is<pair>() ? cons(car(xs), list_copy(cdr(xs))) : xs;
+  }
+
   auto take(object const& x, std::size_t size) -> object
   {
     return 0 < size ? cons(car(x), take(cdr(x), --size)) : unit;
diff --git a/test/srfi-1.ss b/test/srfi-1.ss
index df6e0a747..ff84c5a7c 100644
--- a/test/srfi-1.ss
+++ b/test/srfi-1.ss
@@ -3,6 +3,7 @@
         (only (srfi 1)
               xcons
               cons*
+              list-tabulate
               circular-list
               iota
               circular-list?
@@ -28,6 +29,9 @@
 (check (cons* 'a 'b) => '(a . b))
 (check (cons* 'a 'b 'c) => '(a b . c))
 
+(check (list-tabulate 4 (lambda (x) x)) => '(0 1 2 3))
+(check (list-tabulate 4 number->string) => '("0" "1" "2" "3"))
+
 (check (circular-list 'a) => '#1=(a . #1#))
 (check (circular-list 'a 'b) => '#1=(a b . #1#))
 (check (circular-list 'a 'b 'c) => '#1=(a b c . #1#))
@@ -83,4 +87,4 @@
 
 (check-report)
 
-(exit (check-passed? 48))
+(exit (check-passed? 50))

From 1eccc2ca8122982e5cbd1c3b902ea40f2f602bab Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Sun, 15 Oct 2023 10:57:15 +0900
Subject: [PATCH 15/31] Update procedure `drop` to built-in

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md                      |  6 ++--
 VERSION                        |  2 +-
 basis/srfi-1.ss                | 14 ++++-----
 include/meevax/kernel/list.hpp | 24 +++++++++++----
 src/kernel/boot.cpp            | 55 ++++++++++++++++++----------------
 src/kernel/list.cpp            | 29 +++++++++++++++---
 test/srfi-1.ss                 | 11 ++++++-
 7 files changed, 93 insertions(+), 48 deletions(-)

diff --git a/README.md b/README.md
index a5feb23dd..5ed9841c0 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.46_amd64.deb
+sudo apt install build/meevax_0.5.47_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.46.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.47.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.46_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.47_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index bb49383f1..2bc68242c 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.46
+0.5.47
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index 91533ccb0..997fe9d27 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -8,15 +8,15 @@
 
 (define-library (srfi 1)
   (import (only (meevax pair)
-                cons
+                cons cons*
                 xcons
                 pair?
                 not-pair?
                 car cdr caar cadr cdar cddr caaar caadr cadar caddr cdaar cdadr cddar cdddr caaaar caaadr caadar caaddr cadaar cadadr caddar cadddr cdaaar cdaadr cdadar cdaddr cddaar cddadr cdddar cddddr
                 )
           (only (meevax list)
-                list cons* make-list list-copy circular-list iota null?
-                ; proper-list?
+                list make-list list-copy circular-list iota null?
+                list?
                 circular-list?
                 dotted-list?
                 null-list?
@@ -25,12 +25,13 @@
                 first second third fourth fifth sixth seventh eighth ninth tenth
                 ; car+cdr
                 take
+                drop
 
                 last
                 last-pair
                 )
           (except (scheme base)
-                  cons list make-list list-copy pair? null?
+                  cons list make-list list-copy pair? null? list?
                   car cdr caar cadr cdar cddr
                   list-ref
                   )
@@ -95,11 +96,6 @@
            (if (zero? k)
                (begin (set-cdr! (drop x (- k 1)) '()) x)))
 
-         (define (drop x k)
-           (let rec ((x x) (k k))
-             (if (zero? k) x
-                 (rec (cdr x) (- k 1)))))
-
          (define (take-right x k)
            (let lp ((lag x)
                     (lead (drop x k)))
diff --git a/include/meevax/kernel/list.hpp b/include/meevax/kernel/list.hpp
index cd2a54efb..222d484b1 100644
--- a/include/meevax/kernel/list.hpp
+++ b/include/meevax/kernel/list.hpp
@@ -91,17 +91,18 @@ inline namespace kernel
 
   inline auto cons = [](auto&&... xs) constexpr
   {
-    return (xs | ...);
+    return (std::forward<decltype(xs)>(xs) | ...);
   };
 
   inline auto list = [](auto&&... xs) constexpr
   {
-    return (xs | ... | unit);
+    return (std::forward<decltype(xs)>(xs) | ... | unit);
   };
 
-  inline auto xcons = [](auto&& d, auto&& a) constexpr
+  inline auto xcons = [](auto&& x, auto&& y) constexpr
   {
-    return cons(std::forward<decltype(a)>(a), std::forward<decltype(d)>(d));
+    return cons(std::forward<decltype(y)>(y),
+                std::forward<decltype(x)>(x));
   };
 
   auto make_list(std::size_t, object const& = unit) -> object;
@@ -123,7 +124,7 @@ inline namespace kernel
   template <typename T>
   auto circulate(T&& x)
   {
-    cdr(last_pair(x)) = x;
+    cdr(last_pair(std::forward<decltype(x)>(x))) = x;
   }
 
   template <typename... Ts>
@@ -156,6 +157,19 @@ inline namespace kernel
 
   auto take(object const&, std::size_t) -> object;
 
+  template <typename T>
+  auto drop(T&& x, std::size_t k) -> decltype(x)
+  {
+    if (0 < k)
+    {
+      return drop(cdr(std::forward<decltype(x)>(x)), k - 1);
+    }
+    else
+    {
+      return std::forward<decltype(x)>(x);
+    }
+  }
+
   auto length(object const&) -> std::size_t;
 
   auto append(object const&, object const&) -> object;
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index 74699e243..2f860c970 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -556,31 +556,6 @@ inline namespace kernel
         return xs;
       });
 
-      library.define<procedure>("cons*", [](let & xs)
-      {
-        if (xs.is<null>())
-        {
-          throw error(make<string>("procedure cons* takes at least one arugments, but got"), xs);
-        }
-        else if (cdr(xs).is<null>())
-        {
-          return xs[0];
-        }
-        else
-        {
-          auto node = xs.get();
-
-          while (not cddr(*node).is<null>())
-          {
-            node = cdr(*node).get();
-          }
-
-          cdr(*node) = cadr(*node);
-
-          return xs;
-        }
-      });
-
       library.define<procedure>("make-list", [](let const& xs)
       {
         switch (length(xs))
@@ -737,6 +712,11 @@ inline namespace kernel
         return take(xs[0], xs[1].as<exact_integer>());
       });
 
+      library.define<procedure>("drop", [](let const& xs)
+      {
+        return drop(xs[0], xs[1].as<exact_integer>());
+      });
+
       library.define<procedure>("memq", [](let const& xs) -> auto const&
       {
         return memq(xs[0], xs[1]);
@@ -1045,6 +1025,31 @@ inline namespace kernel
         return cons(xs[0], xs[1]);
       });
 
+      library.define<procedure>("cons*", [](let & xs)
+      {
+        if (xs.is<null>())
+        {
+          throw error(make<string>("procedure cons* takes at least one arugments, but got"), xs);
+        }
+        else if (cdr(xs).is<null>())
+        {
+          return xs[0];
+        }
+        else
+        {
+          auto node = xs.get();
+
+          while (not cddr(*node).is<null>())
+          {
+            node = cdr(*node).get();
+          }
+
+          cdr(*node) = cadr(*node);
+
+          return xs;
+        }
+      });
+
       library.define<procedure>("xcons", [](let const& xs)
       {
         return cons(xs[1], xs[0]);
diff --git a/src/kernel/list.cpp b/src/kernel/list.cpp
index a16c35980..e1598d6c6 100644
--- a/src/kernel/list.cpp
+++ b/src/kernel/list.cpp
@@ -23,12 +23,26 @@ inline namespace kernel
 {
   auto make_list(std::size_t size, object const& x) -> object
   {
-    return 0 < size ? cons(x, make_list(--size, x)) : unit;
+    if (0 < size)
+    {
+      return cons(x, make_list(--size, x));
+    }
+    else
+    {
+      return unit;
+    }
   }
 
   auto iota(std::size_t count, object const& start, object const& step) -> object
   {
-    return 0 < count ? cons(start, iota(count - 1, start + step, step)) : unit;
+    if (0 < count)
+    {
+      return cons(start, iota(count - 1, start + step, step));
+    }
+    else
+    {
+      return unit;
+    }
   }
 
   auto is_list(object const& x0, object const& y0) -> bool
@@ -117,9 +131,16 @@ inline namespace kernel
     return xs.is<pair>() ? cons(car(xs), list_copy(cdr(xs))) : xs;
   }
 
-  auto take(object const& x, std::size_t size) -> object
+  auto take(object const& x, std::size_t k) -> object
   {
-    return 0 < size ? cons(car(x), take(cdr(x), --size)) : unit;
+    if (0 < k)
+    {
+      return cons(car(x), take(cdr(x), k - 1));
+    }
+    else
+    {
+      return unit;
+    }
   }
 
   auto length(object const& xs) -> std::size_t
diff --git a/test/srfi-1.ss b/test/srfi-1.ss
index ff84c5a7c..09a54bc26 100644
--- a/test/srfi-1.ss
+++ b/test/srfi-1.ss
@@ -13,6 +13,7 @@
               list=
               first second third fourth fifth sixth seventh eighth ninth tenth
               take
+              drop
               last
               last-pair
               length+
@@ -66,12 +67,20 @@
 (check (ninth   '(a b c d e f g h i j)) => 'i)
 (check (tenth   '(a b c d e f g h i j)) => 'j)
 
+(check (take '(a b c d e) 0) => '())
 (check (take '(a b c d e) 1) => '(a))
 (check (take '(a b c d e) 2) => '(a b))
 (check (take '(a b c d e) 3) => '(a b c))
 (check (take '(a b c d e) 4) => '(a b c d))
 (check (take '(a b c d e) 5) => '(a b c d e))
 
+(check (drop '(a b c d e) 0) => '(a b c d e))
+(check (drop '(a b c d e) 1) => '(b c d e))
+(check (drop '(a b c d e) 2) => '(c d e))
+(check (drop '(a b c d e) 3) => '(d e))
+(check (drop '(a b c d e) 4) => '(e))
+(check (drop '(a b c d e) 5) => '())
+
 (check (last '(a)) => 'a)
 (check (last '(a b)) => 'b)
 (check (last '(a b c)) => 'c)
@@ -87,4 +96,4 @@
 
 (check-report)
 
-(exit (check-passed? 50))
+(exit (check-passed? 57))

From f863adc1595c590c555c58fb210bebbfe28c4b57 Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Sun, 15 Oct 2023 12:49:41 +0900
Subject: [PATCH 16/31] Update procedure `take!` to built-in

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md                               |  6 ++---
 VERSION                                 |  2 +-
 basis/srfi-1.ss                         |  7 +-----
 include/meevax/kernel/heterogeneous.hpp | 30 ++++++++++++++++++++++---
 include/meevax/kernel/list.hpp          |  2 ++
 include/meevax/kernel/pair.hpp          |  8 ++++---
 include/meevax/kernel/vector.hpp        |  2 ++
 src/kernel/boot.cpp                     |  7 +++++-
 src/kernel/list.cpp                     | 22 +++++++++++++++++-
 src/kernel/pair.cpp                     |  5 +++++
 src/kernel/vector.cpp                   |  5 +++++
 test/srfi-1.ss                          | 11 +++++++--
 12 files changed, 87 insertions(+), 20 deletions(-)

diff --git a/README.md b/README.md
index 5ed9841c0..798c4d0af 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.47_amd64.deb
+sudo apt install build/meevax_0.5.48_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.47.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.48.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.47_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.48_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index 2bc68242c..0ab079f88 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.47
+0.5.48
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index 997fe9d27..fea0e844c 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -20,11 +20,10 @@
                 circular-list?
                 dotted-list?
                 null-list?
-                ; list=
                 list-ref
                 first second third fourth fifth sixth seventh eighth ninth tenth
                 ; car+cdr
-                take
+                take take!
                 drop
 
                 last
@@ -92,10 +91,6 @@
            (values (car pair)
                    (cdr pair)))
 
-         (define (take! x k)
-           (if (zero? k)
-               (begin (set-cdr! (drop x (- k 1)) '()) x)))
-
          (define (take-right x k)
            (let lp ((lag x)
                     (lead (drop x k)))
diff --git a/include/meevax/kernel/heterogeneous.hpp b/include/meevax/kernel/heterogeneous.hpp
index 939e83903..04b22723b 100644
--- a/include/meevax/kernel/heterogeneous.hpp
+++ b/include/meevax/kernel/heterogeneous.hpp
@@ -51,7 +51,7 @@ inline namespace kernel
 
       auto compare([[maybe_unused]] Top const* top) const -> bool override
       {
-        if constexpr (is_equality_comparable_v<Bound>)
+        if constexpr (is_equality_comparable_v<Bound const&>)
         {
           if (auto const* bound = dynamic_cast<Bound const*>(top); bound)
           {
@@ -75,7 +75,7 @@ inline namespace kernel
 
       auto write(std::ostream & os) const -> std::ostream & override
       {
-        if constexpr (is_output_streamable_v<Bound>)
+        if constexpr (is_output_streamable_v<Bound const&>)
         {
           return os << static_cast<Bound const&>(*this);
         }
@@ -87,7 +87,7 @@ inline namespace kernel
 
       auto operator []([[maybe_unused]] std::size_t k) const -> heterogeneous const& override
       {
-        if constexpr (is_array_subscriptable_v<Bound>)
+        if constexpr (is_array_subscriptable_v<Bound const&>)
         {
           return static_cast<Bound const&>(*this)[k];
         }
@@ -96,6 +96,18 @@ inline namespace kernel
           throw std::runtime_error(lexical_cast<std::string>("no viable array subscript operator for ", demangle(type())));
         }
       }
+
+      auto operator []([[maybe_unused]] std::size_t k) -> heterogeneous & override
+      {
+        if constexpr (is_array_subscriptable_v<Bound &>)
+        {
+          return static_cast<Bound &>(*this)[k];
+        }
+        else
+        {
+          throw std::runtime_error(lexical_cast<std::string>("no viable array subscript operator for ", demangle(type())));
+        }
+      }
     };
 
   public:
@@ -236,6 +248,18 @@ inline namespace kernel
       }
     }
 
+    inline auto operator [](std::size_t k) -> heterogeneous &
+    {
+      if (dereferenceable() and *this)
+      {
+        return get()->operator [](k);
+      }
+      else
+      {
+        throw std::runtime_error(lexical_cast<std::string>("no viable array subscript operator for ", demangle(type())));
+      }
+    }
+
     friend auto operator <<(std::ostream & os, heterogeneous const& datum) -> std::ostream &
     {
       return datum.write(os);
diff --git a/include/meevax/kernel/list.hpp b/include/meevax/kernel/list.hpp
index 222d484b1..2b114a64e 100644
--- a/include/meevax/kernel/list.hpp
+++ b/include/meevax/kernel/list.hpp
@@ -157,6 +157,8 @@ inline namespace kernel
 
   auto take(object const&, std::size_t) -> object;
 
+  auto take(object &, std::size_t) -> object;
+
   template <typename T>
   auto drop(T&& x, std::size_t k) -> decltype(x)
   {
diff --git a/include/meevax/kernel/pair.hpp b/include/meevax/kernel/pair.hpp
index 6157bf986..d810de6de 100644
--- a/include/meevax/kernel/pair.hpp
+++ b/include/meevax/kernel/pair.hpp
@@ -52,14 +52,14 @@ inline namespace kernel
 
   struct pair : public std::pair<object, object>
   {
-    template <auto ReadOnly>
+    template <auto Const>
     struct forward_iterator
     {
       using iterator_category = std::forward_iterator_tag;
 
       using value_type = object;
 
-      using reference = std::add_lvalue_reference_t<std::conditional_t<ReadOnly, std::add_const_t<value_type>, value_type>>;
+      using reference = std::add_lvalue_reference_t<std::conditional_t<Const, std::add_const_t<value_type>, value_type>>;
 
       using pointer = std::add_pointer_t<reference>;
 
@@ -67,7 +67,7 @@ inline namespace kernel
 
       using size_type = std::size_t;
 
-      using node_type = std::conditional_t<ReadOnly, pair const*, pair *>;
+      using node_type = std::conditional_t<Const, pair const*, pair *>;
 
       node_type current = nullptr;
 
@@ -141,6 +141,8 @@ inline namespace kernel
 
     virtual auto operator [](std::size_t) const -> object const&;
 
+    virtual auto operator [](std::size_t) -> object &;
+
     constexpr auto begin() noexcept
     {
       return iterator(this);
diff --git a/include/meevax/kernel/vector.hpp b/include/meevax/kernel/vector.hpp
index fb8a7215f..c257161ad 100644
--- a/include/meevax/kernel/vector.hpp
+++ b/include/meevax/kernel/vector.hpp
@@ -39,6 +39,8 @@ inline namespace kernel
     {}
 
     auto operator [](std::size_t) const -> object const&;
+
+    auto operator [](std::size_t) -> object &;
   };
 
   auto operator ==(heterogeneous_vector const&, heterogeneous_vector const&) -> bool;
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index 2f860c970..c60254f2f 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -712,6 +712,11 @@ inline namespace kernel
         return take(xs[0], xs[1].as<exact_integer>());
       });
 
+      library.define<procedure>("take!", [](let & xs)
+      {
+        return take(xs[0], xs[1].as<exact_integer>());
+      });
+
       library.define<procedure>("drop", [](let const& xs)
       {
         return drop(xs[0], xs[1].as<exact_integer>());
@@ -1764,7 +1769,7 @@ inline namespace kernel
 
       library.define<procedure>("vector-set!", [](let & xs)
       {
-        xs[0].as<vector>().vector[xs[1].as<exact_integer>()] = xs[2];
+        xs[0][xs[1].as<exact_integer>()] = xs[2];
       });
 
       library.define<procedure>("vector->list", [](let const& xs)
diff --git a/src/kernel/list.cpp b/src/kernel/list.cpp
index e1598d6c6..35330ae99 100644
--- a/src/kernel/list.cpp
+++ b/src/kernel/list.cpp
@@ -128,7 +128,14 @@ inline namespace kernel
 
   auto list_copy(object const& xs) -> object
   {
-    return xs.is<pair>() ? cons(car(xs), list_copy(cdr(xs))) : xs;
+    if (xs.is<pair>())
+    {
+      return cons(car(xs), list_copy(cdr(xs)));
+    }
+    else
+    {
+      return xs;
+    }
   }
 
   auto take(object const& x, std::size_t k) -> object
@@ -143,6 +150,19 @@ inline namespace kernel
     }
   }
 
+  auto take(object & x, std::size_t k) -> object
+  {
+    if (0 < k)
+    {
+      cdr(drop(x, k - 1)) = unit;
+      return x;
+    }
+    else
+    {
+      return unit;
+    }
+  }
+
   auto length(object const& xs) -> std::size_t
   {
     return std::distance(xs.begin(), xs.end());
diff --git a/src/kernel/pair.cpp b/src/kernel/pair.cpp
index 7ca61c493..3dfc20da4 100644
--- a/src/kernel/pair.cpp
+++ b/src/kernel/pair.cpp
@@ -46,6 +46,11 @@ inline namespace kernel
     return 0 < k ? second[--k] : first;
   }
 
+  auto pair::operator [](std::size_t k) -> object &
+  {
+    return 0 < k ? second[--k] : first;
+  }
+
   auto operator <<(std::ostream & os, pair const& datum) -> std::ostream &
   {
     if (is_circular_list(cdr(datum)))
diff --git a/src/kernel/vector.cpp b/src/kernel/vector.cpp
index 0eb1b7597..ada6da730 100644
--- a/src/kernel/vector.cpp
+++ b/src/kernel/vector.cpp
@@ -39,6 +39,11 @@ inline namespace kernel
     return vector[index];
   }
 
+  auto heterogeneous_vector::operator [](std::size_t index) -> object &
+  {
+    return vector[index];
+  }
+
   auto operator ==(heterogeneous_vector const& v, heterogeneous_vector const& u) -> bool
   {
     return std::equal(std::begin(v.vector), std::end(v.vector),
diff --git a/test/srfi-1.ss b/test/srfi-1.ss
index 09a54bc26..e00179938 100644
--- a/test/srfi-1.ss
+++ b/test/srfi-1.ss
@@ -12,7 +12,7 @@
               null-list?
               list=
               first second third fourth fifth sixth seventh eighth ninth tenth
-              take
+              take take!
               drop
               last
               last-pair
@@ -81,6 +81,13 @@
 (check (drop '(a b c d e) 4) => '(e))
 (check (drop '(a b c d e) 5) => '())
 
+(let ((x '(a b c d e))) (check (take! x 0) => '()) (check x => '(a b c d e)))
+(let ((x '(a b c d e))) (check (take! x 1) => '(a)) (check x => '(a)))
+(let ((x '(a b c d e))) (check (take! x 2) => '(a b)) (check x => '(a b)))
+(let ((x '(a b c d e))) (check (take! x 3) => '(a b c)) (check x => '(a b c)))
+(let ((x '(a b c d e))) (check (take! x 4) => '(a b c d)) (check x => '(a b c d)))
+(let ((x '(a b c d e))) (check (take! x 5) => '(a b c d e)) (check x => '(a b c d e)))
+
 (check (last '(a)) => 'a)
 (check (last '(a b)) => 'b)
 (check (last '(a b c)) => 'c)
@@ -96,4 +103,4 @@
 
 (check-report)
 
-(exit (check-passed? 57))
+(exit (check-passed? 69))

From 437aabddf643e69ba40e53ef3e8622b1bb8a556d Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Sun, 15 Oct 2023 13:51:37 +0900
Subject: [PATCH 17/31] Update procedures `take-right` and `drop-right` to
 built-in

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md                      |  6 ++--
 VERSION                        |  2 +-
 basis/srfi-1.ss                | 17 ++--------
 include/meevax/kernel/list.hpp | 19 ++++-------
 src/kernel/boot.cpp            | 10 ++++++
 src/kernel/list.cpp            | 58 ++++++++++++++++++++++++++++++++++
 test/srfi-1.ss                 | 26 ++++++++++++++-
 7 files changed, 106 insertions(+), 32 deletions(-)

diff --git a/README.md b/README.md
index 798c4d0af..e651639bc 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.48_amd64.deb
+sudo apt install build/meevax_0.5.49_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.48.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.49.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.48_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.49_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index 0ab079f88..b19530f3d 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.48
+0.5.49
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index fea0e844c..efac2028e 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -25,6 +25,8 @@
                 ; car+cdr
                 take take!
                 drop
+                take-right
+                drop-right
 
                 last
                 last-pair
@@ -91,21 +93,6 @@
            (values (car pair)
                    (cdr pair)))
 
-         (define (take-right x k)
-           (let lp ((lag x)
-                    (lead (drop x k)))
-             (if (pair? lead)
-                 (lp (cdr lag)
-                     (cdr lead))
-                 lag)))
-
-         (define (drop-right x k)
-           (let rec ((lag x) (lead (drop x k)))
-             (if (pair? lead)
-                 (cons (car lag)
-                       (rec (cdr lag) (cdr lead)))
-                 '())))
-
          (define (drop-right! x k)
            (let ((lead (drop x k)))
              (if (pair? lead)
diff --git a/include/meevax/kernel/list.hpp b/include/meevax/kernel/list.hpp
index 2b114a64e..423d27b9f 100644
--- a/include/meevax/kernel/list.hpp
+++ b/include/meevax/kernel/list.hpp
@@ -159,18 +159,13 @@ inline namespace kernel
 
   auto take(object &, std::size_t) -> object;
 
-  template <typename T>
-  auto drop(T&& x, std::size_t k) -> decltype(x)
-  {
-    if (0 < k)
-    {
-      return drop(cdr(std::forward<decltype(x)>(x)), k - 1);
-    }
-    else
-    {
-      return std::forward<decltype(x)>(x);
-    }
-  }
+  auto take_right(object const&, std::size_t) -> object const&;
+
+  auto drop(object const&, std::size_t) -> object const&;
+
+  auto drop(object &, std::size_t) -> object &;
+
+  auto drop_right(object const&, std::size_t) -> object;
 
   auto length(object const&) -> std::size_t;
 
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index c60254f2f..fdd0bb08f 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -717,11 +717,21 @@ inline namespace kernel
         return take(xs[0], xs[1].as<exact_integer>());
       });
 
+      library.define<procedure>("take-right", [](let const& xs)
+      {
+        return take_right(xs[0], xs[1].as<exact_integer>());
+      });
+
       library.define<procedure>("drop", [](let const& xs)
       {
         return drop(xs[0], xs[1].as<exact_integer>());
       });
 
+      library.define<procedure>("drop-right", [](let const& xs)
+      {
+        return drop_right(xs[0], xs[1].as<exact_integer>());
+      });
+
       library.define<procedure>("memq", [](let const& xs) -> auto const&
       {
         return memq(xs[0], xs[1]);
diff --git a/src/kernel/list.cpp b/src/kernel/list.cpp
index 35330ae99..33d10a056 100644
--- a/src/kernel/list.cpp
+++ b/src/kernel/list.cpp
@@ -163,6 +163,64 @@ inline namespace kernel
     }
   }
 
+  auto take_right(object const& x, object const& y) -> object const&
+  {
+    if (y.is<pair>())
+    {
+      return take_right(cdr(x), cdr(y));
+    }
+    else
+    {
+      return x;
+    }
+  }
+
+  auto take_right(object const& x, std::size_t k) -> object const&
+  {
+    return take_right(x, drop(x, k));
+  }
+
+  auto drop(object const& x, std::size_t k) -> object const&
+  {
+    if (0 < k)
+    {
+      return drop(cdr(x), k - 1);
+    }
+    else
+    {
+      return x;
+    }
+  }
+
+  auto drop(object & x, std::size_t k) -> object &
+  {
+    if (0 < k)
+    {
+      return drop(cdr(x), k - 1);
+    }
+    else
+    {
+      return x;
+    }
+  }
+
+  auto drop_right(object const& x, object const& y) -> object
+  {
+    if (y.is<pair>())
+    {
+      return cons(car(x), drop_right(cdr(x), cdr(y)));
+    }
+    else
+    {
+      return unit;
+    }
+  }
+
+  auto drop_right(object const& x, std::size_t k) -> object
+  {
+    return drop_right(x, drop(x, k));
+  }
+
   auto length(object const& xs) -> std::size_t
   {
     return std::distance(xs.begin(), xs.end());
diff --git a/test/srfi-1.ss b/test/srfi-1.ss
index e00179938..1c6b82a70 100644
--- a/test/srfi-1.ss
+++ b/test/srfi-1.ss
@@ -14,6 +14,8 @@
               first second third fourth fifth sixth seventh eighth ninth tenth
               take take!
               drop
+              take-right
+              drop-right
               last
               last-pair
               length+
@@ -81,6 +83,28 @@
 (check (drop '(a b c d e) 4) => '(e))
 (check (drop '(a b c d e) 5) => '())
 
+(check (take-right '(a b c d e) 0) => '())
+(check (take-right '(a b c d e) 1) => '(e))
+(check (take-right '(a b c d e) 2) => '(d e))
+(check (take-right '(a b c d e) 3) => '(c d e))
+(check (take-right '(a b c d e) 4) => '(b c d e))
+(check (take-right '(a b c d e) 5) => '(a b c d e))
+(check (take-right '(a b c . x) 0) => 'x)
+(check (take-right '(a b c . x) 1) => '(c . x))
+(check (take-right '(a b c . x) 2) => '(b c . x))
+(check (take-right '(a b c . x) 3) => '(a b c . x))
+
+(check (drop-right '(a b c d e) 0) => '(a b c d e))
+(check (drop-right '(a b c d e) 1) => '(a b c d))
+(check (drop-right '(a b c d e) 2) => '(a b c))
+(check (drop-right '(a b c d e) 3) => '(a b))
+(check (drop-right '(a b c d e) 4) => '(a))
+(check (drop-right '(a b c d e) 5) => '())
+(check (drop-right '(a b c . x) 0) => '(a b c))
+(check (drop-right '(a b c . x) 1) => '(a b))
+(check (drop-right '(a b c . x) 2) => '(a))
+(check (drop-right '(a b c . x) 3) => '())
+
 (let ((x '(a b c d e))) (check (take! x 0) => '()) (check x => '(a b c d e)))
 (let ((x '(a b c d e))) (check (take! x 1) => '(a)) (check x => '(a)))
 (let ((x '(a b c d e))) (check (take! x 2) => '(a b)) (check x => '(a b)))
@@ -103,4 +127,4 @@
 
 (check-report)
 
-(exit (check-passed? 69))
+(exit (check-passed? 89))

From 9173c06b05d155ac866fd46d2a87cfdf8df4e01d Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Sun, 15 Oct 2023 14:28:39 +0900
Subject: [PATCH 18/31] Update procedure `drop-right!` to built-in

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md                      |  6 +++---
 VERSION                        |  2 +-
 basis/srfi-1.ss                | 26 ++++----------------------
 include/meevax/kernel/list.hpp |  2 ++
 src/kernel/boot.cpp            |  5 +++++
 src/kernel/list.cpp            | 25 +++++++++++++++++++++++++
 test/srfi-1.ss                 | 25 ++++++++++++++++++-------
 7 files changed, 58 insertions(+), 33 deletions(-)

diff --git a/README.md b/README.md
index e651639bc..8e2a132f2 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.49_amd64.deb
+sudo apt install build/meevax_0.5.50_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.49.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.50.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.49_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.50_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index b19530f3d..1e7ed0369 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.49
+0.5.50
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index efac2028e..3228ceb40 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -16,17 +16,10 @@
                 )
           (only (meevax list)
                 list make-list list-copy circular-list iota null?
-                list?
-                circular-list?
-                dotted-list?
-                null-list?
-                list-ref
-                first second third fourth fifth sixth seventh eighth ninth tenth
-                ; car+cdr
-                take take!
-                drop
-                take-right
-                drop-right
+                list? circular-list? dotted-list? null-list?
+                list-ref first second third fourth fifth sixth seventh eighth ninth tenth
+                take take! take-right
+                drop drop-right drop-right!
 
                 last
                 last-pair
@@ -93,17 +86,6 @@
            (values (car pair)
                    (cdr pair)))
 
-         (define (drop-right! x k)
-           (let ((lead (drop x k)))
-             (if (pair? lead)
-                 (let rec ((lag x)
-                           (lead (cdr lead)))
-                   (if (pair? lead)
-                       (rec (cdr lag)
-                            (cdr lead))
-                       (begin (set-cdr! lag '()) x)))
-                 '())))
-
          (define (split-at x k)
            (let recur ((lis x) (k k))
              (if (zero? k) (values '() lis)
diff --git a/include/meevax/kernel/list.hpp b/include/meevax/kernel/list.hpp
index 423d27b9f..a8dcec320 100644
--- a/include/meevax/kernel/list.hpp
+++ b/include/meevax/kernel/list.hpp
@@ -167,6 +167,8 @@ inline namespace kernel
 
   auto drop_right(object const&, std::size_t) -> object;
 
+  auto drop_right(object &, std::size_t) -> object;
+
   auto length(object const&) -> std::size_t;
 
   auto append(object const&, object const&) -> object;
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index fdd0bb08f..0cb76fb9f 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -732,6 +732,11 @@ inline namespace kernel
         return drop_right(xs[0], xs[1].as<exact_integer>());
       });
 
+      library.define<procedure>("drop-right!", [](let & xs)
+      {
+        return drop_right(xs[0], xs[1].as<exact_integer>());
+      });
+
       library.define<procedure>("memq", [](let const& xs) -> auto const&
       {
         return memq(xs[0], xs[1]);
diff --git a/src/kernel/list.cpp b/src/kernel/list.cpp
index 33d10a056..cb72c33ad 100644
--- a/src/kernel/list.cpp
+++ b/src/kernel/list.cpp
@@ -221,6 +221,31 @@ inline namespace kernel
     return drop_right(x, drop(x, k));
   }
 
+  auto drop_right(object & x, object const& y) -> void
+  {
+    if (y.is<pair>())
+    {
+      drop_right(cdr(x), cdr(y));
+    }
+    else
+    {
+      cdr(x) = unit;
+    }
+  }
+
+  auto drop_right(object & x, std::size_t k) -> object
+  {
+    if (let const y = drop(x, k); y.is<pair>())
+    {
+      drop_right(x, cdr(y));
+      return x;
+    }
+    else
+    {
+      return unit;
+    }
+  }
+
   auto length(object const& xs) -> std::size_t
   {
     return std::distance(xs.begin(), xs.end());
diff --git a/test/srfi-1.ss b/test/srfi-1.ss
index 1c6b82a70..9413a46c6 100644
--- a/test/srfi-1.ss
+++ b/test/srfi-1.ss
@@ -15,7 +15,7 @@
               take take!
               drop
               take-right
-              drop-right
+              drop-right drop-right!
               last
               last-pair
               length+
@@ -105,13 +105,24 @@
 (check (drop-right '(a b c . x) 2) => '(a))
 (check (drop-right '(a b c . x) 3) => '())
 
-(let ((x '(a b c d e))) (check (take! x 0) => '()) (check x => '(a b c d e)))
-(let ((x '(a b c d e))) (check (take! x 1) => '(a)) (check x => '(a)))
-(let ((x '(a b c d e))) (check (take! x 2) => '(a b)) (check x => '(a b)))
-(let ((x '(a b c d e))) (check (take! x 3) => '(a b c)) (check x => '(a b c)))
-(let ((x '(a b c d e))) (check (take! x 4) => '(a b c d)) (check x => '(a b c d)))
+(let ((x '(a b c d e))) (check (take! x 0) => '())          (check x => '(a b c d e)))
+(let ((x '(a b c d e))) (check (take! x 1) => '(a))         (check x => '(a)))
+(let ((x '(a b c d e))) (check (take! x 2) => '(a b))       (check x => '(a b)))
+(let ((x '(a b c d e))) (check (take! x 3) => '(a b c))     (check x => '(a b c)))
+(let ((x '(a b c d e))) (check (take! x 4) => '(a b c d))   (check x => '(a b c d)))
 (let ((x '(a b c d e))) (check (take! x 5) => '(a b c d e)) (check x => '(a b c d e)))
 
+(let ((x '(a b c d e))) (check (drop-right! x 0) => '(a b c d e)) (check x => '(a b c d e)))
+(let ((x '(a b c d e))) (check (drop-right! x 1) => '(a b c d))   (check x => '(a b c d)))
+(let ((x '(a b c d e))) (check (drop-right! x 2) => '(a b c))     (check x => '(a b c)))
+(let ((x '(a b c d e))) (check (drop-right! x 3) => '(a b))       (check x => '(a b)))
+(let ((x '(a b c d e))) (check (drop-right! x 4) => '(a))         (check x => '(a)))
+(let ((x '(a b c d e))) (check (drop-right! x 5) => '())          (check x => '(a b c d e)))
+(let ((x '(a b c . z))) (check (drop-right! x 0) => '(a b c))     (check x => '(a b c)))
+(let ((x '(a b c . z))) (check (drop-right! x 1) => '(a b))       (check x => '(a b)))
+(let ((x '(a b c . z))) (check (drop-right! x 2) => '(a))         (check x => '(a)))
+(let ((x '(a b c . z))) (check (drop-right! x 3) => '())          (check x => '(a b c . z)))
+
 (check (last '(a)) => 'a)
 (check (last '(a b)) => 'b)
 (check (last '(a b c)) => 'c)
@@ -127,4 +138,4 @@
 
 (check-report)
 
-(exit (check-passed? 89))
+(exit (check-passed? 109))

From 2d1294c1bb0be7a871bc1de9632fb611c2f3e9bd Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Sun, 15 Oct 2023 17:38:03 +0900
Subject: [PATCH 19/31] Update procedure `length+` to built-in

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md                      |  6 +++---
 VERSION                        |  2 +-
 basis/srfi-1.ss                | 22 +++++-----------------
 include/meevax/kernel/pair.hpp |  2 +-
 src/kernel/boot.cpp            |  5 +++++
 src/kernel/list.cpp            |  4 ++--
 test/srfi-1.ss                 |  5 ++++-
 7 files changed, 21 insertions(+), 25 deletions(-)

diff --git a/README.md b/README.md
index 8e2a132f2..0df4abf18 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.50_amd64.deb
+sudo apt install build/meevax_0.5.51_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.50.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.51.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.50_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.51_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index 1e7ed0369..c9ac536f4 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.50
+0.5.51
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index 3228ceb40..13f20eb5d 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -20,14 +20,14 @@
                 list-ref first second third fourth fifth sixth seventh eighth ninth tenth
                 take take! take-right
                 drop drop-right drop-right!
-
-                last
-                last-pair
+                last last-pair
+                length length+
                 )
           (except (scheme base)
                   cons list make-list list-copy pair? null? list?
                   car cdr caar cadr cdar cddr
                   list-ref
+                  length
                   )
           (srfi 8))
 
@@ -88,7 +88,8 @@
 
          (define (split-at x k)
            (let recur ((lis x) (k k))
-             (if (zero? k) (values '() lis)
+             (if (zero? k)
+                 (values '() lis)
                  (receive (prefix suffix) (recur (cdr lis) (- k 1))
                           (values (cons (car lis) prefix) suffix)))))
 
@@ -100,19 +101,6 @@
                  (set-cdr! prev '())
                  (values x suffix))))
 
-         (define (length+ x) ; Returns #f if X is circular.
-           (let rec ((x x) (lag x) (len 0))
-             (if (pair? x)
-                 (let ((x (cdr x))
-                       (len (+ len 1)))
-                   (if (pair? x)
-                       (let ((x   (cdr x))
-                             (lag (cdr lag))
-                             (len (+ len 1)))
-                         (and (not (eq? x lag)) (rec x lag len)))
-                       len))
-                 len)))
-
          (define (append! . lists)
            (let lp ((lists lists) (prev '())) ; First, scan through lists looking for a non-empty one.
              (if (not (pair? lists)) prev
diff --git a/include/meevax/kernel/pair.hpp b/include/meevax/kernel/pair.hpp
index d810de6de..614470329 100644
--- a/include/meevax/kernel/pair.hpp
+++ b/include/meevax/kernel/pair.hpp
@@ -92,7 +92,7 @@ inline namespace kernel
 
       auto operator ++() -> decltype(auto)
       {
-        if (current = current->second.get(); current == initial)
+        if (current = current->second.get(); current == initial or (current and current->type() != typeid(pair)))
         {
           current = nullptr;
         }
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index 0cb76fb9f..51bdd09fb 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -632,6 +632,11 @@ inline namespace kernel
         return make<exact_integer>(length(xs[0]));
       });
 
+      library.define<procedure>("length+", [](let const& xs)
+      {
+        return is_circular_list(xs[0]) ? f : make<exact_integer>(length(xs[0]));
+      });
+
       library.define<procedure>("append", [](let const& xs)
       {
         return std::accumulate(std::begin(xs), std::end(xs), unit, append);
diff --git a/src/kernel/list.cpp b/src/kernel/list.cpp
index cb72c33ad..a815c03d8 100644
--- a/src/kernel/list.cpp
+++ b/src/kernel/list.cpp
@@ -246,9 +246,9 @@ inline namespace kernel
     }
   }
 
-  auto length(object const& xs) -> std::size_t
+  auto length(object const& x) -> std::size_t
   {
-    return std::distance(xs.begin(), xs.end());
+    return std::distance(x.begin(), x.end());
   }
 
   auto append(object const& x, object const& y) -> object
diff --git a/test/srfi-1.ss b/test/srfi-1.ss
index 9413a46c6..ba444339f 100644
--- a/test/srfi-1.ss
+++ b/test/srfi-1.ss
@@ -132,10 +132,13 @@
 (check (last-pair '(a b c)) => '(c))
 (check (last-pair '(a b c . d)) => '(c . d))
 
+(check (length '(a b c)) => 3)
+(check (length '(a b . c)) => 2)
+
 (check (length+ '(a b c)) => 3)
 (check (length+ '(a b . c)) => 2)
 (check (length+ '#1=(a b c . #1#)) => #f)
 
 (check-report)
 
-(exit (check-passed? 109))
+(exit (check-passed? 111))

From b06ec444a955a1c30efe9ec688348337b60977e4 Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Sun, 15 Oct 2023 18:14:08 +0900
Subject: [PATCH 20/31] Update procedure `append!` to built-in

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md                      |  6 ++---
 VERSION                        |  2 +-
 basis/srfi-1.ss                | 18 ++------------
 include/meevax/kernel/list.hpp |  2 ++
 src/kernel/boot.cpp            |  7 +++++-
 src/kernel/list.cpp            | 17 +++++++++++++
 test/srfi-1.ss                 | 44 +++++++++++++++++++++++++++++++++-
 7 files changed, 74 insertions(+), 22 deletions(-)

diff --git a/README.md b/README.md
index 0df4abf18..38fdd1bfc 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.51_amd64.deb
+sudo apt install build/meevax_0.5.52_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.51.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.52.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.51_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.52_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index c9ac536f4..04d79fca4 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.51
+0.5.52
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index 13f20eb5d..2d8a1b1fb 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -22,12 +22,14 @@
                 drop drop-right drop-right!
                 last last-pair
                 length length+
+                append append!
                 )
           (except (scheme base)
                   cons list make-list list-copy pair? null? list?
                   car cdr caar cadr cdar cddr
                   list-ref
                   length
+                  append
                   )
           (srfi 8))
 
@@ -101,22 +103,6 @@
                  (set-cdr! prev '())
                  (values x suffix))))
 
-         (define (append! . lists)
-           (let lp ((lists lists) (prev '())) ; First, scan through lists looking for a non-empty one.
-             (if (not (pair? lists)) prev
-                 (let ((first (car lists))
-                       (rest (cdr lists)))
-                   (if (not (pair? first)) (lp rest first)
-                       (let lp2 ((tail-cons (last-pair first)) ; Now, do the splicing.
-                                 (rest rest))
-                         (if (pair? rest)
-                             (let ((next (car rest))
-                                   (rest (cdr rest)))
-                               (set-cdr! tail-cons next)
-                               (lp2 (if (pair? next) (last-pair next) tail-cons)
-                                    rest))
-                             first)))))))
-
          (define (concatenate xs)
            (reduce-right append '() xs))
 
diff --git a/include/meevax/kernel/list.hpp b/include/meevax/kernel/list.hpp
index a8dcec320..3d6c3a19b 100644
--- a/include/meevax/kernel/list.hpp
+++ b/include/meevax/kernel/list.hpp
@@ -173,6 +173,8 @@ inline namespace kernel
 
   auto append(object const&, object const&) -> object;
 
+  auto append(object &, object const&) -> object &;
+
   auto reverse(object const&, object const& = unit) -> object;
 
   template <typename F>
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index 51bdd09fb..6242e7bb8 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -639,7 +639,12 @@ inline namespace kernel
 
       library.define<procedure>("append", [](let const& xs)
       {
-        return std::accumulate(std::begin(xs), std::end(xs), unit, append);
+        return std::accumulate(xs.begin(), xs.end(), unit, [](auto&&... xs) { return append(std::forward<decltype(xs)>(xs)...); });
+      });
+
+      library.define<procedure>("append!", [](let & xs)
+      {
+        return std::accumulate(xs.begin(), xs.end(), unit, [](auto&&... xs) { return append(std::forward<decltype(xs)>(xs)...); });
       });
 
       library.define<procedure>("reverse", [](let const& xs)
diff --git a/src/kernel/list.cpp b/src/kernel/list.cpp
index a815c03d8..c8d60b5a2 100644
--- a/src/kernel/list.cpp
+++ b/src/kernel/list.cpp
@@ -263,6 +263,23 @@ inline namespace kernel
     }
   }
 
+  auto append(object & x, object const& y) -> object &
+  {
+    if (x.is<null>())
+    {
+      return x = y;
+    }
+    else if (y.is<null>())
+    {
+      return x;
+    }
+    else
+    {
+      cdr(last_pair(x)) = y;
+      return x;
+    }
+  }
+
   auto reverse(object const& xs, object const& a) -> object
   {
     if (xs.is<pair>())
diff --git a/test/srfi-1.ss b/test/srfi-1.ss
index ba444339f..d690d75a0 100644
--- a/test/srfi-1.ss
+++ b/test/srfi-1.ss
@@ -19,6 +19,7 @@
               last
               last-pair
               length+
+              append!
               )
         (srfi 78))
 
@@ -139,6 +140,47 @@
 (check (length+ '(a b . c)) => 2)
 (check (length+ '#1=(a b c . #1#)) => #f)
 
+(check (append '(a) '(b)) => '(a b))
+(check (append '(a) '(b c d)) => '(a b c d))
+(check (append '(a (b)) '((c))) => '(a (b) (c)))
+(check (append '(a b) '(c . d)) => '(a b c . d))
+(check (append '() 'a) => 'a)
+(check (append '(a b)) => '(a b))
+(check (append) => '())
+
+(let ((x '(a))
+      (y '(b)))
+  (check (append! x y) => '(a b))
+  (check x => '(a b))
+  (check y => '(b)))
+
+(let ((x '(a))
+      (y '(b c d)))
+  (check (append! x y) => '(a b c d))
+  (check x => '(a b c d))
+  (check y => '(b c d)))
+
+(let ((x '(a (b)))
+      (y '((c))))
+  (check (append! x y) => '(a (b) (c)))
+  (check x => '(a (b) (c)))
+  (check y => '((c))))
+
+(let ((x '(a b))
+      (y '(c . d)))
+  (check (append! x y) => '(a b c . d))
+  (check x => '(a b c . d))
+  (check y => '(c . d)))
+
+(let ((x '())
+      (y 'a))
+  (check (append! x y) => 'a)
+  (check x => '())
+  (check y => 'a))
+
+(check (append! '(a b)) => '(a b))
+(check (append!) => '())
+
 (check-report)
 
-(exit (check-passed? 111))
+(exit (check-passed? 135))

From f1fc74955831d58fe2a44f8e27d4d90d9741610f Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Sun, 15 Oct 2023 18:31:54 +0900
Subject: [PATCH 21/31] Update procedures `concatenate` and `concatenate!` to
 built-in

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md           |  6 +++---
 VERSION             |  2 +-
 basis/srfi-1.ss     |  9 +++-----
 src/kernel/boot.cpp | 10 +++++++++
 test/srfi-1.ss      | 50 ++++++++++++++++++++++++++++++---------------
 5 files changed, 51 insertions(+), 26 deletions(-)

diff --git a/README.md b/README.md
index 38fdd1bfc..6d2417ab6 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.52_amd64.deb
+sudo apt install build/meevax_0.5.53_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.52.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.53.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.52_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.53_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index 04d79fca4..e113daf9f 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.52
+0.5.53
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index 2d8a1b1fb..34cb732d4 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -23,6 +23,8 @@
                 last last-pair
                 length length+
                 append append!
+                reverse
+                concatenate concatenate!
                 )
           (except (scheme base)
                   cons list make-list list-copy pair? null? list?
@@ -30,6 +32,7 @@
                   list-ref
                   length
                   append
+                  reverse
                   )
           (srfi 8))
 
@@ -103,12 +106,6 @@
                  (set-cdr! prev '())
                  (values x suffix))))
 
-         (define (concatenate xs)
-           (reduce-right append '() xs))
-
-         (define (concatenate! xs)
-           (reduce-right append! '() xs))
-
          (define (reverse! lis)
            (let lp ((lis lis) (ans '()))
              (if (null-list? lis) ans
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index 6242e7bb8..e198507e9 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -652,6 +652,16 @@ inline namespace kernel
         return reverse(xs[0]);
       });
 
+      library.define<procedure>("concatenate", [](let const& xs)
+      {
+        return std::accumulate(xs[0].begin(), xs[0].end(), unit, [](auto&&... xs) { return append(std::forward<decltype(xs)>(xs)...); });
+      });
+
+      library.define<procedure>("concatenate!", [](let & xs)
+      {
+        return std::accumulate(xs[0].begin(), xs[0].end(), unit, [](auto&&... xs) { return append(std::forward<decltype(xs)>(xs)...); });
+      });
+
       library.define<procedure>("list-copy", [](let const& xs)
       {
         return list_copy(xs[0]);
diff --git a/test/srfi-1.ss b/test/srfi-1.ss
index d690d75a0..2b12de0fb 100644
--- a/test/srfi-1.ss
+++ b/test/srfi-1.ss
@@ -1,25 +1,15 @@
 (import (scheme base)
         (scheme process-context)
         (only (srfi 1)
-              xcons
-              cons*
-              list-tabulate
-              circular-list
-              iota
-              circular-list?
-              dotted-list?
-              not-pair?
-              null-list?
+              xcons cons* list-tabulate circular-list iota
+              circular-list? dotted-list? not-pair? null-list?
               list=
               first second third fourth fifth sixth seventh eighth ninth tenth
-              take take!
-              drop
-              take-right
-              drop-right drop-right!
-              last
-              last-pair
+              take take! drop take-right drop-right drop-right!
+              last last-pair
               length+
               append!
+              concatenate concatenate!
               )
         (srfi 78))
 
@@ -181,6 +171,34 @@
 (check (append! '(a b)) => '(a b))
 (check (append!) => '())
 
+(check (concatenate '((1 2 3) (4 5 6) (7 8 9))) => '(1 2 3 4 5 6 7 8 9))
+(check (concatenate '((1 2 3) (4 5 6) (7 . ...))) => '(1 2 3 4 5 6 7 . ...))
+(check (concatenate '((1 2 3) (4 5 6) ...)) => '(1 2 3 4 5 6 . ...))
+
+(let ((x '((1 2 3)
+           (4 5 6)
+           (7 8 9))))
+  (check (concatenate! x) => '(1 2 3 4 5 6 7 8 9))
+  (check x => '((1 2 3 4 5 6 7 8 9)
+                (4 5 6 7 8 9)
+                (7 8 9))))
+
+(let ((x '((1 2 3)
+           (4 5 6)
+           (7 . ...))))
+  (check (concatenate x) => '(1 2 3 4 5 6 7 . ...))
+  (check x => '((1 2 3 4 5 6 7 . ...)
+                (4 5 6 7 . ...)
+                (7 . ...))))
+
+(let ((x '((1 2 3)
+           (4 5 6)
+           ...)))
+  (check (concatenate x) => '(1 2 3 4 5 6 . ...))
+  (check x => '((1 2 3 4 5 6 . ...)
+                (4 5 6 . ...)
+                ...)))
+
 (check-report)
 
-(exit (check-passed? 135))
+(exit (check-passed? 144))

From 218b23206e259f5f0b31d6f3500190a942417aa6 Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Sun, 15 Oct 2023 19:45:41 +0900
Subject: [PATCH 22/31] Update procedure `reverse!` to built-in

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md                      |   6 +-
 VERSION                        |   2 +-
 basis/srfi-1.ss                |   9 +--
 include/meevax/kernel/list.hpp |   4 +-
 src/kernel/boot.cpp            |  13 +++-
 src/kernel/list.cpp            |  26 +++++++
 test/srfi-1.ss                 | 138 ++++++++++++---------------------
 7 files changed, 91 insertions(+), 107 deletions(-)

diff --git a/README.md b/README.md
index 6d2417ab6..5af8ab3ca 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.53_amd64.deb
+sudo apt install build/meevax_0.5.54_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.53.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.54.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.53_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.54_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index e113daf9f..5f782db3c 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.53
+0.5.54
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index 34cb732d4..c34fec2d2 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -23,7 +23,7 @@
                 last last-pair
                 length length+
                 append append!
-                reverse
+                reverse reverse!
                 concatenate concatenate!
                 )
           (except (scheme base)
@@ -106,13 +106,6 @@
                  (set-cdr! prev '())
                  (values x suffix))))
 
-         (define (reverse! lis)
-           (let lp ((lis lis) (ans '()))
-             (if (null-list? lis) ans
-                 (let ((tail (cdr lis)))
-                   (set-cdr! lis ans)
-                   (lp tail lis)))))
-
          (define (append-reverse rev-head tail)
            (let lp ((rev-head rev-head) (tail tail))
              (if (null-list? rev-head) tail
diff --git a/include/meevax/kernel/list.hpp b/include/meevax/kernel/list.hpp
index 3d6c3a19b..98c995c59 100644
--- a/include/meevax/kernel/list.hpp
+++ b/include/meevax/kernel/list.hpp
@@ -175,7 +175,9 @@ inline namespace kernel
 
   auto append(object &, object const&) -> object &;
 
-  auto reverse(object const&, object const& = unit) -> object;
+  auto reverse(object const&) -> object;
+
+  auto reverse(object &) -> object;
 
   template <typename F>
   auto map(F f, object const& xs) -> object
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index e198507e9..29fe385ac 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -639,12 +639,12 @@ inline namespace kernel
 
       library.define<procedure>("append", [](let const& xs)
       {
-        return std::accumulate(xs.begin(), xs.end(), unit, [](auto&&... xs) { return append(std::forward<decltype(xs)>(xs)...); });
+        return std::accumulate(xs.begin(), xs.end(), unit, [](let const& x, let const& y) { return append(x, y); });
       });
 
       library.define<procedure>("append!", [](let & xs)
       {
-        return std::accumulate(xs.begin(), xs.end(), unit, [](auto&&... xs) { return append(std::forward<decltype(xs)>(xs)...); });
+        return std::accumulate(xs.begin(), xs.end(), unit, [](let & x, let const& y) { return append(x, y); });
       });
 
       library.define<procedure>("reverse", [](let const& xs)
@@ -652,14 +652,19 @@ inline namespace kernel
         return reverse(xs[0]);
       });
 
+      library.define<procedure>("reverse!", [](let & xs)
+      {
+        return reverse(xs[0]);
+      });
+
       library.define<procedure>("concatenate", [](let const& xs)
       {
-        return std::accumulate(xs[0].begin(), xs[0].end(), unit, [](auto&&... xs) { return append(std::forward<decltype(xs)>(xs)...); });
+        return std::accumulate(xs[0].begin(), xs[0].end(), unit, [](let const& x, let const& y) { return append(x, y); });
       });
 
       library.define<procedure>("concatenate!", [](let & xs)
       {
-        return std::accumulate(xs[0].begin(), xs[0].end(), unit, [](auto&&... xs) { return append(std::forward<decltype(xs)>(xs)...); });
+        return std::accumulate(xs[0].begin(), xs[0].end(), unit, [](let & x, let const& y) { return append(x, y); });
       });
 
       library.define<procedure>("list-copy", [](let const& xs)
diff --git a/src/kernel/list.cpp b/src/kernel/list.cpp
index c8d60b5a2..ba0379958 100644
--- a/src/kernel/list.cpp
+++ b/src/kernel/list.cpp
@@ -292,6 +292,32 @@ inline namespace kernel
     }
   }
 
+  auto reverse(object const& xs) -> object
+  {
+    return reverse(xs, unit);
+  }
+
+  auto reverse(object & xs, object const& a) -> object
+  {
+    if (xs.is<null>())
+    {
+      return a;
+    }
+    else
+    {
+      let tail = cdr(xs);
+
+      cdr(xs) = a;
+
+      return reverse(tail, xs);
+    }
+  }
+
+  auto reverse(object & xs) -> object
+  {
+    return reverse(xs, unit);
+  }
+
   auto memq(object const& x, object const& xs) -> object const&
   {
     if (xs.is<pair>())
diff --git a/test/srfi-1.ss b/test/srfi-1.ss
index 2b12de0fb..273ae515c 100644
--- a/test/srfi-1.ss
+++ b/test/srfi-1.ss
@@ -9,6 +9,7 @@
               last last-pair
               length+
               append!
+              reverse!
               concatenate concatenate!
               )
         (srfi 78))
@@ -60,12 +61,18 @@
 (check (ninth   '(a b c d e f g h i j)) => 'i)
 (check (tenth   '(a b c d e f g h i j)) => 'j)
 
-(check (take '(a b c d e) 0) => '())
-(check (take '(a b c d e) 1) => '(a))
-(check (take '(a b c d e) 2) => '(a b))
-(check (take '(a b c d e) 3) => '(a b c))
-(check (take '(a b c d e) 4) => '(a b c d))
-(check (take '(a b c d e) 5) => '(a b c d e))
+(let ((x '(a b c d e))) (check (take  x 0) => '())          (check x => '(a b c d e)))
+(let ((x '(a b c d e))) (check (take! x 0) => '())          (check x => '(a b c d e)))
+(let ((x '(a b c d e))) (check (take  x 1) => '(a))         (check x => '(a b c d e)))
+(let ((x '(a b c d e))) (check (take! x 1) => '(a))         (check x => '(a)))
+(let ((x '(a b c d e))) (check (take  x 2) => '(a b))       (check x => '(a b c d e)))
+(let ((x '(a b c d e))) (check (take! x 2) => '(a b))       (check x => '(a b)))
+(let ((x '(a b c d e))) (check (take  x 3) => '(a b c))     (check x => '(a b c d e)))
+(let ((x '(a b c d e))) (check (take! x 3) => '(a b c))     (check x => '(a b c)))
+(let ((x '(a b c d e))) (check (take  x 4) => '(a b c d))   (check x => '(a b c d e)))
+(let ((x '(a b c d e))) (check (take! x 4) => '(a b c d))   (check x => '(a b c d)))
+(let ((x '(a b c d e))) (check (take  x 5) => '(a b c d e)) (check x => '(a b c d e)))
+(let ((x '(a b c d e))) (check (take! x 5) => '(a b c d e)) (check x => '(a b c d e)))
 
 (check (drop '(a b c d e) 0) => '(a b c d e))
 (check (drop '(a b c d e) 1) => '(b c d e))
@@ -85,33 +92,25 @@
 (check (take-right '(a b c . x) 2) => '(b c . x))
 (check (take-right '(a b c . x) 3) => '(a b c . x))
 
-(check (drop-right '(a b c d e) 0) => '(a b c d e))
-(check (drop-right '(a b c d e) 1) => '(a b c d))
-(check (drop-right '(a b c d e) 2) => '(a b c))
-(check (drop-right '(a b c d e) 3) => '(a b))
-(check (drop-right '(a b c d e) 4) => '(a))
-(check (drop-right '(a b c d e) 5) => '())
-(check (drop-right '(a b c . x) 0) => '(a b c))
-(check (drop-right '(a b c . x) 1) => '(a b))
-(check (drop-right '(a b c . x) 2) => '(a))
-(check (drop-right '(a b c . x) 3) => '())
-
-(let ((x '(a b c d e))) (check (take! x 0) => '())          (check x => '(a b c d e)))
-(let ((x '(a b c d e))) (check (take! x 1) => '(a))         (check x => '(a)))
-(let ((x '(a b c d e))) (check (take! x 2) => '(a b))       (check x => '(a b)))
-(let ((x '(a b c d e))) (check (take! x 3) => '(a b c))     (check x => '(a b c)))
-(let ((x '(a b c d e))) (check (take! x 4) => '(a b c d))   (check x => '(a b c d)))
-(let ((x '(a b c d e))) (check (take! x 5) => '(a b c d e)) (check x => '(a b c d e)))
-
+(let ((x '(a b c d e))) (check (drop-right  x 0) => '(a b c d e)) (check x => '(a b c d e)))
 (let ((x '(a b c d e))) (check (drop-right! x 0) => '(a b c d e)) (check x => '(a b c d e)))
+(let ((x '(a b c d e))) (check (drop-right  x 1) => '(a b c d))   (check x => '(a b c d e)))
 (let ((x '(a b c d e))) (check (drop-right! x 1) => '(a b c d))   (check x => '(a b c d)))
+(let ((x '(a b c d e))) (check (drop-right  x 2) => '(a b c))     (check x => '(a b c d e)))
 (let ((x '(a b c d e))) (check (drop-right! x 2) => '(a b c))     (check x => '(a b c)))
+(let ((x '(a b c d e))) (check (drop-right  x 3) => '(a b))       (check x => '(a b c d e)))
 (let ((x '(a b c d e))) (check (drop-right! x 3) => '(a b))       (check x => '(a b)))
+(let ((x '(a b c d e))) (check (drop-right  x 4) => '(a))         (check x => '(a b c d e)))
 (let ((x '(a b c d e))) (check (drop-right! x 4) => '(a))         (check x => '(a)))
+(let ((x '(a b c d e))) (check (drop-right  x 5) => '())          (check x => '(a b c d e)))
 (let ((x '(a b c d e))) (check (drop-right! x 5) => '())          (check x => '(a b c d e)))
+(let ((x '(a b c . z))) (check (drop-right  x 0) => '(a b c))     (check x => '(a b c . z)))
 (let ((x '(a b c . z))) (check (drop-right! x 0) => '(a b c))     (check x => '(a b c)))
+(let ((x '(a b c . z))) (check (drop-right  x 1) => '(a b))       (check x => '(a b c . z)))
 (let ((x '(a b c . z))) (check (drop-right! x 1) => '(a b))       (check x => '(a b)))
+(let ((x '(a b c . z))) (check (drop-right  x 2) => '(a))         (check x => '(a b c . z)))
 (let ((x '(a b c . z))) (check (drop-right! x 2) => '(a))         (check x => '(a)))
+(let ((x '(a b c . z))) (check (drop-right  x 3) => '())          (check x => '(a b c . z)))
 (let ((x '(a b c . z))) (check (drop-right! x 3) => '())          (check x => '(a b c . z)))
 
 (check (last '(a)) => 'a)
@@ -130,75 +129,34 @@
 (check (length+ '(a b . c)) => 2)
 (check (length+ '#1=(a b c . #1#)) => #f)
 
-(check (append '(a) '(b)) => '(a b))
-(check (append '(a) '(b c d)) => '(a b c d))
-(check (append '(a (b)) '((c))) => '(a (b) (c)))
-(check (append '(a b) '(c . d)) => '(a b c . d))
-(check (append '() 'a) => 'a)
-(check (append '(a b)) => '(a b))
-(check (append) => '())
-
-(let ((x '(a))
-      (y '(b)))
-  (check (append! x y) => '(a b))
-  (check x => '(a b))
-  (check y => '(b)))
-
-(let ((x '(a))
-      (y '(b c d)))
-  (check (append! x y) => '(a b c d))
-  (check x => '(a b c d))
-  (check y => '(b c d)))
-
-(let ((x '(a (b)))
-      (y '((c))))
-  (check (append! x y) => '(a (b) (c)))
-  (check x => '(a (b) (c)))
-  (check y => '((c))))
-
-(let ((x '(a b))
-      (y '(c . d)))
-  (check (append! x y) => '(a b c . d))
-  (check x => '(a b c . d))
-  (check y => '(c . d)))
-
-(let ((x '())
-      (y 'a))
-  (check (append! x y) => 'a)
-  (check x => '())
-  (check y => 'a))
-
+(let ((x '(a))     (y '(b)))     (check (append  x y) => '(a b))       (check x => '(a))         (check y => '(b)))
+(let ((x '(a))     (y '(b)))     (check (append! x y) => '(a b))       (check x => '(a b))       (check y => '(b)))
+(let ((x '(a))     (y '(b c d))) (check (append  x y) => '(a b c d))   (check x => '(a))         (check y => '(b c d)))
+(let ((x '(a))     (y '(b c d))) (check (append! x y) => '(a b c d))   (check x => '(a b c d))   (check y => '(b c d)))
+(let ((x '(a (b))) (y '((c))))   (check (append  x y) => '(a (b) (c))) (check x => '(a (b)))     (check y => '((c))))
+(let ((x '(a (b))) (y '((c))))   (check (append! x y) => '(a (b) (c))) (check x => '(a (b) (c))) (check y => '((c))))
+(let ((x '(a b))   (y '(c . d))) (check (append  x y) => '(a b c . d)) (check x => '(a b))       (check y => '(c . d)))
+(let ((x '(a b))   (y '(c . d))) (check (append! x y) => '(a b c . d)) (check x => '(a b c . d)) (check y => '(c . d)))
+(let ((x '())      (y 'a))       (check (append  x y) => 'a)           (check x => '())          (check y => 'a))
+(let ((x '())      (y 'a))       (check (append! x y) => 'a)           (check x => '())          (check y => 'a))
+
+(check (append  '(a b)) => '(a b))
 (check (append! '(a b)) => '(a b))
+(check (append)  => '())
 (check (append!) => '())
 
-(check (concatenate '((1 2 3) (4 5 6) (7 8 9))) => '(1 2 3 4 5 6 7 8 9))
-(check (concatenate '((1 2 3) (4 5 6) (7 . ...))) => '(1 2 3 4 5 6 7 . ...))
-(check (concatenate '((1 2 3) (4 5 6) ...)) => '(1 2 3 4 5 6 . ...))
-
-(let ((x '((1 2 3)
-           (4 5 6)
-           (7 8 9))))
-  (check (concatenate! x) => '(1 2 3 4 5 6 7 8 9))
-  (check x => '((1 2 3 4 5 6 7 8 9)
-                (4 5 6 7 8 9)
-                (7 8 9))))
-
-(let ((x '((1 2 3)
-           (4 5 6)
-           (7 . ...))))
-  (check (concatenate x) => '(1 2 3 4 5 6 7 . ...))
-  (check x => '((1 2 3 4 5 6 7 . ...)
-                (4 5 6 7 . ...)
-                (7 . ...))))
-
-(let ((x '((1 2 3)
-           (4 5 6)
-           ...)))
-  (check (concatenate x) => '(1 2 3 4 5 6 . ...))
-  (check x => '((1 2 3 4 5 6 . ...)
-                (4 5 6 . ...)
-                ...)))
+(let ((x '(a b c)))             (check (reverse  x) => '(c b a))             (check x => '(a b c)))
+(let ((x '(a b c)))             (check (reverse! x) => '(c b a))             (check x => '(a)))
+(let ((x '(a (b c) d (e (f))))) (check (reverse  x) => '((e (f)) d (b c) a)) (check x => '(a (b c) d (e (f)))))
+(let ((x '(a (b c) d (e (f))))) (check (reverse! x) => '((e (f)) d (b c) a)) (check x => '(a)))
+
+(let ((x '((1 2 3) (4 5 6) (7 8 9))))   (check (concatenate  x) => '(1 2 3 4 5 6 7 8 9))   (check x => '((1 2 3) (4 5 6) (7 8 9))))
+(let ((x '((1 2 3) (4 5 6) (7 8 9))))   (check (concatenate! x) => '(1 2 3 4 5 6 7 8 9))   (check x => '((1 2 3 4 5 6 7 8 9) (4 5 6 7 8 9) (7 8 9))))
+(let ((x '((1 2 3) (4 5 6) (7 . ...)))) (check (concatenate  x) => '(1 2 3 4 5 6 7 . ...)) (check x => '((1 2 3) (4 5 6) (7 . ...))))
+(let ((x '((1 2 3) (4 5 6) (7 . ...)))) (check (concatenate! x) => '(1 2 3 4 5 6 7 . ...)) (check x => '((1 2 3 4 5 6 7 . ...) (4 5 6 7 . ...) (7 . ...))))
+(let ((x '((1 2 3) (4 5 6) ...)))       (check (concatenate  x) => '(1 2 3 4 5 6 . ...))   (check x => '((1 2 3) (4 5 6) ...)))
+(let ((x '((1 2 3) (4 5 6) ...)))       (check (concatenate! x) => '(1 2 3 4 5 6 . ...))   (check x => '((1 2 3 4 5 6 . ...) (4 5 6 . ...) ...)))
 
 (check-report)
 
-(exit (check-passed? 144))
+(exit (check-passed? 181))

From 8fdd2e3852d70aed2cea5b2d3ff6081765b21d8e Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Mon, 16 Oct 2023 23:17:25 +0900
Subject: [PATCH 23/31] Update procedures `alist-cons` and `alist-copy` to
 built-in

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md                                     |   6 +-
 VERSION                                       |   2 +-
 basis/srfi-1.ss                               | 124 +++++++++++-------
 include/meevax/kernel/list.hpp                |   4 +
 .../meevax/kernel/syntactic_environment.hpp   |   2 +-
 src/kernel/boot.cpp                           |  16 ++-
 src/kernel/list.cpp                           |  14 ++
 test/srfi-1.ss                                |  11 +-
 8 files changed, 123 insertions(+), 56 deletions(-)

diff --git a/README.md b/README.md
index 5af8ab3ca..c948c6034 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.54_amd64.deb
+sudo apt install build/meevax_0.5.55_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.54.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.55.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.54_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.55_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index 5f782db3c..abfc20ea6 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.54
+0.5.55
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index c34fec2d2..479a32876 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -7,33 +7,61 @@
 |#
 
 (define-library (srfi 1)
-  (import (only (meevax pair)
-                cons cons*
-                xcons
-                pair?
-                not-pair?
-                car cdr caar cadr cdar cddr caaar caadr cadar caddr cdaar cdadr cddar cdddr caaaar caaadr caadar caaddr cadaar cadadr caddar cadddr cdaaar cdaadr cdadar cdaddr cddaar cddadr cdddar cddddr
-                )
+  (import (only (meevax boolean) not)
+          (only (meevax core) begin call-with-current-continuation! define if lambda letrec quote set!)
           (only (meevax list)
-                list make-list list-copy circular-list iota null?
-                list? circular-list? dotted-list? null-list?
-                list-ref first second third fourth fifth sixth seventh eighth ninth tenth
-                take take! take-right
-                drop drop-right drop-right!
-                last last-pair
-                length length+
-                append append!
-                reverse reverse!
-                concatenate concatenate!
-                )
-          (except (scheme base)
-                  cons list make-list list-copy pair? null? list?
-                  car cdr caar cadr cdar cddr
-                  list-ref
-                  length
-                  append
-                  reverse
-                  )
+            alist-cons
+            alist-copy
+            append
+            append!
+            assq
+            assv
+            circular-list
+            circular-list?
+            concatenate
+            concatenate!
+            dotted-list?
+            drop
+            drop-right
+            drop-right!
+            eighth
+            fifth
+            first
+            fourth
+            iota
+            last
+            last-pair
+            length
+            length+
+            list
+            list?
+            list-copy
+            list-ref
+            make-list
+            memq
+            memv
+            ninth
+            null?
+            null-list?
+            reverse
+            reverse!
+            second
+            seventh
+            sixth
+            take
+            take!
+            take-right
+            tenth
+            third
+            )
+          (only (meevax pair)
+            caaaar caaadr caaar caadar caaddr caadr caar cadaar cadadr cadar
+            caddar cadddr caddr cadr car cdaaar cdaadr cdaar cdadar cdaddr
+            cdadr cdar cddaar cddadr cddar cdddar cddddr cdddr cddr cdr cons
+            cons* not-pair? pair? set-car! set-cdr! xcons)
+          (only (scheme r5rs)
+            cond and or let let* eqv? eq? equal? = < zero? + - member assoc
+            apply map values call-with-values)
           (srfi 8))
 
   (export cons list xcons cons* make-list list-tabulate list-copy circular-list
@@ -92,19 +120,25 @@
                    (cdr pair)))
 
          (define (split-at x k)
-           (let recur ((lis x) (k k))
-             (if (zero? k)
-                 (values '() lis)
-                 (receive (prefix suffix) (recur (cdr lis) (- k 1))
-                          (values (cons (car lis) prefix) suffix)))))
+           (if (zero? k)
+               (values '() x)
+               (call-with-values (lambda ()
+                                   (split-at (cdr x)
+                                             (- k 1)))
+                                 (lambda (prefix suffix)
+                                   (values (cons (car x)
+                                                 prefix)
+                                           suffix)))))
 
          (define (split-at! x k)
            (if (zero? k)
                (values '() x)
-               (let* ((prev (drop x (- k 1)))
-                      (suffix (cdr prev)))
-                 (set-cdr! prev '())
-                 (values x suffix))))
+               ((lambda (prefix-last)
+                  ((lambda (suffix)
+                     (set-cdr! prefix-last '())
+                     (values x suffix))
+                   (cdr prefix-last)))
+                (drop x (- k 1)))))
 
          (define (append-reverse rev-head tail)
            (let lp ((rev-head rev-head) (tail tail))
@@ -209,7 +243,8 @@
                        (lp tail (f lis ans)))))))
 
          (define (reduce f ridentity lis)
-           (if (null-list? lis) ridentity
+           (if (null-list? lis)
+               ridentity
                (fold f (car lis) (cdr lis))))
 
          (define (fold-right f knil x . xs)
@@ -359,7 +394,9 @@
                                 (values in (if (pair? in) (cons elt out) lis))))))))
 
          (define (remove satisfy? x)
-           (filter (lambda (y) (not (satisfy? y))) x))
+           (filter (lambda (y)
+                     (not (satisfy? y)))
+                   x))
 
          ; Things are much simpler if you are willing to push N stack frames & do N
          ; set-cdr! writes, where N is the length of the answer.
@@ -512,7 +549,9 @@
                        (values '() lis))))))
 
          (define (break break? x)
-           (span (lambda (x) (not (break? x))) x))
+           (span (lambda (x)
+                   (not (break? x)))
+                 x))
 
          (define (span! pred lis)
            (if (or (null-list? lis) (not (pred (car lis)))) (values '() lis)
@@ -553,15 +592,6 @@
                           (new-tail (recur (delete! x tail elt=))))
                      (if (eq? tail new-tail) lis (cons x new-tail)))))))
 
-         (define (alist-cons key datum alist)
-           (cons (cons key datum) alist))
-
-         (define (alist-copy alist)
-           (map (lambda (each)
-                  (cons (car each)
-                        (cdr each)))
-                alist))
-
          (define (alist-delete key alist . maybe-=)
            (let ((= (if (pair? maybe-=) (car maybe-=) equal?)))
              (filter (lambda (elt) (not (= key (car elt)))) alist)))
diff --git a/include/meevax/kernel/list.hpp b/include/meevax/kernel/list.hpp
index 98c995c59..7331c49f2 100644
--- a/include/meevax/kernel/list.hpp
+++ b/include/meevax/kernel/list.hpp
@@ -193,6 +193,10 @@ inline namespace kernel
 
   auto assv(object const&, object const&) -> object const&;
 
+  auto alist_cons(object const&, object const&, object const&) -> object;
+
+  auto alist_copy(object const&) -> object;
+
   template <typename F>
   auto filter(F test, object const& xs) -> object
   {
diff --git a/include/meevax/kernel/syntactic_environment.hpp b/include/meevax/kernel/syntactic_environment.hpp
index 9bb728b36..f77338d19 100644
--- a/include/meevax/kernel/syntactic_environment.hpp
+++ b/include/meevax/kernel/syntactic_environment.hpp
@@ -1016,7 +1016,7 @@ inline namespace kernel
                                   free_variables);
                 });
 
-                xs = cons(cons(free_variable, inject), xs);
+                xs = alist_cons(free_variable, inject, xs);
               }
 
               return xs;
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index 29fe385ac..48c7cca44 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -781,6 +781,16 @@ inline namespace kernel
       {
         return assv(xs[0], xs[1]);
       });
+
+      library.define<procedure>("alist-cons", [](let const& xs)
+      {
+        return alist_cons(xs[0], xs[1], xs[2]);
+      });
+
+      library.define<procedure>("alist-copy", [](let const& xs)
+      {
+        return alist_copy(xs[0]);
+      });
     });
 
     define<library>("(meevax number)", [](library & library)
@@ -1747,9 +1757,9 @@ inline namespace kernel
         {
           if (auto const position = std::string_view(*iter).find_first_of("="); position != std::string::npos)
           {
-            alist = cons(cons(make<string>(std::string(*iter, position)),
-                              make<string>(std::string(*iter + position + 1))),
-                         alist);
+            alist = alist_cons(make<string>(std::string(*iter, position)),
+                               make<string>(std::string(*iter + position + 1)),
+                               alist);
           }
         }
 
diff --git a/src/kernel/list.cpp b/src/kernel/list.cpp
index ba0379958..d112f4596 100644
--- a/src/kernel/list.cpp
+++ b/src/kernel/list.cpp
@@ -394,6 +394,20 @@ inline namespace kernel
     }
   }
 
+  auto alist_cons(object const& key, object const& datum, object const& alist) -> object
+  {
+    return cons(cons(key, datum), alist);
+  }
+
+  auto alist_copy(object const& alist) -> object
+  {
+    return map([](auto&& x)
+               {
+                 return cons(car(x), cdr(x));
+               },
+               alist);
+  }
+
   auto longest_common_tail(let const& a, let const& b) -> object const&
   {
     if (a.is<null>() or b.is<null>() or eq(a, b))
diff --git a/test/srfi-1.ss b/test/srfi-1.ss
index 273ae515c..1404aedfd 100644
--- a/test/srfi-1.ss
+++ b/test/srfi-1.ss
@@ -6,11 +6,13 @@
               list=
               first second third fourth fifth sixth seventh eighth ninth tenth
               take take! drop take-right drop-right drop-right!
+              split-at split-at!
               last last-pair
               length+
               append!
               reverse!
               concatenate concatenate!
+              alist-cons alist-copy
               )
         (srfi 78))
 
@@ -113,6 +115,9 @@
 (let ((x '(a b c . z))) (check (drop-right  x 3) => '())          (check x => '(a b c . z)))
 (let ((x '(a b c . z))) (check (drop-right! x 3) => '())          (check x => '(a b c . z)))
 
+(let ((x '(a b c d e f g h))) (check (call-with-values (lambda () (split-at  x 3)) (lambda (x xs) (list x xs))) => '((a b c) (d e f g h))) (check x => '(a b c d e f g h)))
+(let ((x '(a b c d e f g h))) (check (call-with-values (lambda () (split-at! x 3)) (lambda (x xs) (list x xs))) => '((a b c) (d e f g h))) (check x => '(a b c)))
+
 (check (last '(a)) => 'a)
 (check (last '(a b)) => 'b)
 (check (last '(a b c)) => 'c)
@@ -157,6 +162,10 @@
 (let ((x '((1 2 3) (4 5 6) ...)))       (check (concatenate  x) => '(1 2 3 4 5 6 . ...))   (check x => '((1 2 3) (4 5 6) ...)))
 (let ((x '((1 2 3) (4 5 6) ...)))       (check (concatenate! x) => '(1 2 3 4 5 6 . ...))   (check x => '((1 2 3 4 5 6 . ...) (4 5 6 . ...) ...)))
 
+(check (alist-cons 'a 1 '((b . 2) (c . 3))) => '((a . 1) (b . 2) (c . 3)))
+
+(check (alist-copy '((a . 1) (b . 2) (c . 3))) => '((a . 1) (b . 2) (c . 3)))
+
 (check-report)
 
-(exit (check-passed? 181))
+(exit (check-passed? 187))

From 0ff6e21c95baf36aa6bbbbb453aeb014c4020e79 Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Mon, 16 Oct 2023 23:30:50 +0900
Subject: [PATCH 24/31] Update procedures `append-reverse` and
 `append-reverse!` to built-in

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md                      |  6 +++---
 VERSION                        |  2 +-
 basis/srfi-1.ss                | 14 ++------------
 include/meevax/kernel/list.hpp |  4 ++++
 src/kernel/boot.cpp            | 10 ++++++++++
 src/kernel/list.cpp            | 28 ++++++++++++++++++++++++++++
 test/srfi-1.ss                 |  6 +++++-
 7 files changed, 53 insertions(+), 17 deletions(-)

diff --git a/README.md b/README.md
index c948c6034..908425525 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.55_amd64.deb
+sudo apt install build/meevax_0.5.56_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.55.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.56.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.55_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.56_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index abfc20ea6..1450d0419 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.55
+0.5.56
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index 479a32876..7c28e2711 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -14,6 +14,8 @@
             alist-copy
             append
             append!
+            append-reverse
+            append-reverse!
             assq
             assv
             circular-list
@@ -140,18 +142,6 @@
                    (cdr prefix-last)))
                 (drop x (- k 1)))))
 
-         (define (append-reverse rev-head tail)
-           (let lp ((rev-head rev-head) (tail tail))
-             (if (null-list? rev-head) tail
-                 (lp (cdr rev-head) (cons (car rev-head) tail)))))
-
-         (define (append-reverse! rev-head tail)
-           (let lp ((rev-head rev-head) (tail tail))
-             (if (null-list? rev-head) tail
-                 (let ((next-rev (cdr rev-head)))
-                   (set-cdr! rev-head tail)
-                   (lp next-rev rev-head)))))
-
          (define (zip list1 . more-lists)
            (apply map list list1 more-lists))
 
diff --git a/include/meevax/kernel/list.hpp b/include/meevax/kernel/list.hpp
index 7331c49f2..887e59413 100644
--- a/include/meevax/kernel/list.hpp
+++ b/include/meevax/kernel/list.hpp
@@ -175,6 +175,10 @@ inline namespace kernel
 
   auto append(object &, object const&) -> object &;
 
+  auto append_reverse(object const&, object const&) -> object;
+
+  auto append_reverse(object &, object const&) -> object;
+
   auto reverse(object const&) -> object;
 
   auto reverse(object &) -> object;
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index 48c7cca44..b1b7386b7 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -647,6 +647,16 @@ inline namespace kernel
         return std::accumulate(xs.begin(), xs.end(), unit, [](let & x, let const& y) { return append(x, y); });
       });
 
+      library.define<procedure>("append-reverse", [](let const& xs)
+      {
+        return append_reverse(xs[0], xs[1]);
+      });
+
+      library.define<procedure>("append-reverse!", [](let & xs)
+      {
+        return append_reverse(xs[0], xs[1]);
+      });
+
       library.define<procedure>("reverse", [](let const& xs)
       {
         return reverse(xs[0]);
diff --git a/src/kernel/list.cpp b/src/kernel/list.cpp
index d112f4596..2789fc490 100644
--- a/src/kernel/list.cpp
+++ b/src/kernel/list.cpp
@@ -280,6 +280,34 @@ inline namespace kernel
     }
   }
 
+  auto append_reverse(object const& x, object const& y) -> object
+  {
+    if (x.is<null>())
+    {
+      return y;
+    }
+    else
+    {
+      return append_reverse(cdr(x), cons(car(x), y));
+    }
+  }
+
+  auto append_reverse(object & x, object const& y) -> object
+  {
+    if (x.is<null>())
+    {
+      return y;
+    }
+    else
+    {
+      let const cdr_x = cdr(x);
+
+      cdr(x) = y;
+
+      return append_reverse(cdr_x, x);
+    }
+  }
+
   auto reverse(object const& xs, object const& a) -> object
   {
     if (xs.is<pair>())
diff --git a/test/srfi-1.ss b/test/srfi-1.ss
index 1404aedfd..32ec9812b 100644
--- a/test/srfi-1.ss
+++ b/test/srfi-1.ss
@@ -12,6 +12,7 @@
               append!
               reverse!
               concatenate concatenate!
+              append-reverse append-reverse!
               alist-cons alist-copy
               )
         (srfi 78))
@@ -162,10 +163,13 @@
 (let ((x '((1 2 3) (4 5 6) ...)))       (check (concatenate  x) => '(1 2 3 4 5 6 . ...))   (check x => '((1 2 3) (4 5 6) ...)))
 (let ((x '((1 2 3) (4 5 6) ...)))       (check (concatenate! x) => '(1 2 3 4 5 6 . ...))   (check x => '((1 2 3 4 5 6 . ...) (4 5 6 . ...) ...)))
 
+(let ((x '(3 2 1)) (y '(4 5 6))) (check (append-reverse  x y) => '(1 2 3 4 5 6)) (check x => '(3 2 1))   (check y => '(4 5 6)))
+(let ((x '(3 2 1)) (y '(4 5 6))) (check (append-reverse! x y) => '(1 2 3 4 5 6)) (check x => '(3 4 5 6)) (check y => '(4 5 6)))
+
 (check (alist-cons 'a 1 '((b . 2) (c . 3))) => '((a . 1) (b . 2) (c . 3)))
 
 (check (alist-copy '((a . 1) (b . 2) (c . 3))) => '((a . 1) (b . 2) (c . 3)))
 
 (check-report)
 
-(exit (check-passed? 187))
+(exit (check-passed? 193))

From c194efca623c1b0e8b8c496b16a0021bd6297d1a Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Sun, 22 Oct 2023 01:11:35 +0900
Subject: [PATCH 25/31] Cleanup

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md       |    6 +-
 VERSION         |    2 +-
 basis/]         |    0
 basis/srfi-1.ss | 1528 +++++++++++++++++++++++++----------------------
 test/srfi-1.ss  |  294 ++++++++-
 5 files changed, 1097 insertions(+), 733 deletions(-)
 create mode 100644 basis/]

diff --git a/README.md b/README.md
index 908425525..ae923f820 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.56_amd64.deb
+sudo apt install build/meevax_0.5.57_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.56.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.57.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.56_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.57_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index 1450d0419..7da0228ab 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.56
+0.5.57
diff --git a/basis/] b/basis/]
new file mode 100644
index 000000000..e69de29bb
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index 7c28e2711..d013e8222 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -10,112 +10,122 @@
   (import (only (meevax boolean) not)
           (only (meevax core) begin call-with-current-continuation! define if lambda letrec quote set!)
           (only (meevax list)
-            alist-cons
-            alist-copy
-            append
-            append!
-            append-reverse
-            append-reverse!
-            assq
-            assv
-            circular-list
-            circular-list?
-            concatenate
-            concatenate!
-            dotted-list?
-            drop
-            drop-right
-            drop-right!
-            eighth
-            fifth
-            first
-            fourth
-            iota
-            last
-            last-pair
-            length
-            length+
-            list
-            list?
-            list-copy
-            list-ref
-            make-list
-            memq
-            memv
-            ninth
-            null?
-            null-list?
-            reverse
-            reverse!
-            second
-            seventh
-            sixth
-            take
-            take!
-            take-right
-            tenth
-            third
-            )
+            alist-cons alist-copy append append! append-reverse append-reverse!
+            assq assv circular-list circular-list? concatenate concatenate!
+            dotted-list? drop drop-right drop-right! eighth fifth first fourth
+            iota last last-pair length length+ list list? list-copy list-ref
+            make-list memq memv ninth null? null-list? reverse reverse! second
+            seventh sixth take take! take-right tenth third)
           (only (meevax pair)
-            caaaar caaadr caaar caadar caaddr caadr caar cadaar cadadr cadar
-            caddar cadddr caddr cadr car cdaaar cdaadr cdaar cdadar cdaddr
-            cdadr cdar cddaar cddadr cddar cdddar cddddr cdddr cddr cdr cons
-            cons* not-pair? pair? set-car! set-cdr! xcons)
+            car cdr caar cadr cdar cddr caaar caadr cadar caddr cdaar cdadr
+            cddar cdddr caaaar caaadr caadar caaddr cadaar cadadr caddar cadddr
+            cdaaar cdaadr cdadar cdaddr cddaar cddadr cdddar cddddr cons cons*
+            not-pair? pair? set-car! set-cdr! xcons)
           (only (scheme r5rs)
             cond and or let let* eqv? eq? equal? = < zero? + - member assoc
             apply map values call-with-values)
-          (srfi 8))
-
-  (export cons list xcons cons* make-list list-tabulate list-copy circular-list
-          iota pair? null? proper-list? circular-list? dotted-list? not-pair?
-          null-list? list= car cdr caar cadr cdar cddr caaar caadr cadar caddr
-          cdaar cdadr cddar cdddr caaaar caaadr caadar caaddr cadaar cadadr
-          caddar cadddr cdaaar cdaadr cdadar cdaddr cddaar cddadr cdddar cddddr
-          list-ref first second third fourth fifth sixth seventh eighth ninth
-          tenth car+cdr take drop take-right drop-right take! drop-right!
-          split-at split-at! last last-pair length length+ append concatenate
-          reverse append! concatenate! reverse! append-reverse append-reverse!
-          zip unzip1 unzip2 unzip3 unzip4 unzip5 count map for-each fold unfold
-          pair-fold reduce fold-right unfold-right pair-fold-right reduce-right
-          append-map append-map! map! pair-for-each filter-map map-in-order
-          filter partition remove filter! partition! remove! member memq memv
-          find find-tail any every list-index take-while drop-while take-while!
-          span break span! break! delete delete-duplicates delete!
-          delete-duplicates! assoc assq assv alist-cons alist-copy alist-delete
-          alist-delete! lset<= lset= lset-adjoin lset-union lset-union!
-          lset-intersection lset-intersection! lset-difference lset-difference!
-          lset-xor lset-xor! lset-diff+intersection lset-diff+intersection!
+          (only (srfi 8) receive)
+          (only (srfi 23) error))
+
+  (export ; Constructors
+          cons list xcons cons* make-list list-tabulate list-copy circular-list
+          iota
+
+          ; Predicates
+          pair? null? proper-list? circular-list? dotted-list? not-pair?
+          null-list? list=
+
+          ; Selectors
+          car cdr caar cadr cdar cddr caaar caadr cadar caddr cdaar cdadr cddar
+          cdddr caaaar caaadr caadar caaddr cadaar cadadr caddar cadddr cdaaar
+          cdaadr cdadar cdaddr cddaar cddadr cdddar cddddr
+          list-ref
+          first second third fourth fifth sixth seventh eighth ninth tenth
+          car+cdr
+          take take! take-right
+          drop drop-right drop-right!
+          split-at split-at!
+          last last-pair
+
+          ; Miscellaneous: length, append, concatenate, reverse, zip & count
+          length length+
+          append append!
+          concatenate concatenate!
+          reverse reverse!
+          append-reverse append-reverse!
+          zip unzip1 unzip2 unzip3 unzip4 unzip5
+          count
+
+          ; Fold, unfold & map
+          map map! filter-map map-in-order
+          fold fold-right
+          unfold unfold-right
+          pair-fold pair-fold-right
+          reduce reduce-right
+          append-map append-map!
+          for-each pair-for-each
+
+          ; Filtering & partitioning
+          filter filter!
+          partition partition!
+          remove remove!
+
+          ; Searching
+          memq memv member
+          find find-tail
+          any every list-index
+          take-while take-while!
+          drop-while
+          span span!
+          break break!
+
+          ; Deleting
+          delete delete!
+          delete-duplicates delete-duplicates!
+
+          ; Association lists
+          assq assv assoc alist-cons alist-copy alist-delete alist-delete!
+
+          ; Set operations on lists
+          lset<= lset=
+          lset-adjoin
+          lset-union lset-union!
+          lset-intersection lset-intersection!
+          lset-difference lset-difference!
+          lset-xor lset-xor!
+          lset-diff+intersection lset-diff+intersection!
+
+          ; Primitive side-effects
           set-car! set-cdr!)
 
   (begin (define (list-tabulate k f)
-           (letrec ((list-tabulate (lambda (i)
-                                     (if (< i k)
-                                         (cons (f i)
-                                               (list-tabulate (+ i 1)))
-                                         '()))))
-             (list-tabulate 0)))
+           (let recur ((i 0))
+             (if (< i k)
+                 (cons (f i)
+                       (recur (+ i 1)))
+                 '())))
 
          (define proper-list? list?)
 
-         (define (list= = . lists)
-           (or (null? lists) ; special case
-               (let lp1 ((list-a (car lists))
-                         (others (cdr lists)))
-                 (or (null? others)
-                     (let ((list-b (car others))
-                           (others (cdr others)))
-                       (if (eq? list-a list-b) ; EQ? => LIST=
-                           (lp1 list-b others)
-                           (let lp2 ((pair-a list-a)
-                                     (pair-b list-b))
-                             (if (null-list? pair-a)
-                                 (and (null-list? pair-b)
-                                      (lp1 list-b others))
-                                 (and (not (null-list? pair-b))
-                                      (= (car pair-a)
-                                         (car pair-b))
-                                      (lp2 (cdr pair-a)
-                                           (cdr pair-b)))))))))))
+         (define (list= x=? . xss)
+           (or (null? xss)
+               (let outer ((xs (car xss))
+                           (xss (cdr xss)))
+                 (or (null? xss)
+                     (let ((ys (car xss))
+                           (xss (cdr xss)))
+                       (if (eq? xs ys)
+                           (outer ys xss)
+                           (let inner ((a xs)
+                                       (b ys))
+                             (if (null-list? a)
+                                 (and (null-list? b)
+                                      (outer ys xss))
+                                 (and (not (null-list? b))
+                                      (x=? (car a)
+                                           (car b))
+                                      (inner (cdr a)
+                                             (cdr b)))))))))))
 
          (define (car+cdr pair)
            (values (car pair)
@@ -135,658 +145,760 @@
          (define (split-at! x k)
            (if (zero? k)
                (values '() x)
-               ((lambda (prefix-last)
-                  ((lambda (suffix)
-                     (set-cdr! prefix-last '())
-                     (values x suffix))
-                   (cdr prefix-last)))
-                (drop x (- k 1)))))
-
-         (define (zip list1 . more-lists)
-           (apply map list list1 more-lists))
-
-         (define (unzip1 lis)
-           (map car lis))
-
-         (define (unzip2 lis)
-           (let recur ((lis lis))
-             (if (null-list? lis) (values lis lis) ; Use NOT-PAIR? to handle
-                 (let ((elt (car lis)))      ; dotted lists.
-                   (receive (a b) (recur (cdr lis))
-                            (values (cons (car  elt) a)
-                                    (cons (cadr elt) b)))))))
-
-         (define (unzip3 lis)
-           (let recur ((lis lis))
-             (if (null-list? lis) (values lis lis lis)
-                 (let ((elt (car lis)))
-                   (receive (a b c) (recur (cdr lis))
-                            (values (cons (car   elt) a)
-                                    (cons (cadr  elt) b)
-                                    (cons (caddr elt) c)))))))
-
-         (define (unzip4 lis)
-           (let recur ((lis lis))
-             (if (null-list? lis) (values lis lis lis lis)
-                 (let ((elt (car lis)))
-                   (receive (a b c d) (recur (cdr lis))
-                            (values (cons (car    elt) a)
-                                    (cons (cadr   elt) b)
-                                    (cons (caddr  elt) c)
-                                    (cons (cadddr elt) d)))))))
-
-         (define (unzip5 lis)
-           (let recur ((lis lis))
-             (if (null-list? lis) (values lis lis lis lis lis)
-                 (let ((elt (car lis)))
-                   (receive (a b c d e) (recur (cdr lis))
-                            (values (cons (car     elt) a)
-                                    (cons (cadr    elt) b)
-                                    (cons (caddr   elt) c)
-                                    (cons (cadddr  elt) d)
-                                    (cons (car (cddddr  elt)) e)))))))
-
-         (define (count pred list1 . lists)
-           (if (pair? lists)
-               (let lp ((list1 list1) (lists lists) (i 0))
-                 (if (null-list? list1) i
-                     (receive (as ds) (%cars+cdrs lists)
-                              (if (null? as) i
-                                  (lp (cdr list1) ds
-                                      (if (apply pred (car list1) as) (+ i 1) i))))))
-               (let lp ((lis list1) (i 0))
-                 (if (null-list? lis) i
-                     (lp (cdr lis) (if (pred (car lis)) (+ i 1) i))))))
-
-         (define (fold kons knil lis1 . lists)
-           (if (pair? lists)
-               (let lp ((lists (cons lis1 lists)) (ans knil))
-                 (receive (cars+ans cdrs) (%cars+cdrs+ lists ans)
-                          (if (null? cars+ans) ans ; Done.
-                              (lp cdrs (apply kons cars+ans)))))
-               (let lp ((lis lis1) (ans knil))
-                 (if (null-list? lis) ans
-                     (lp (cdr lis) (kons (car lis) ans))))))
-
-         (define (unfold p f g seed . maybe-tail-gen)
-           (if (pair? maybe-tail-gen)
-               (let ((tail-gen (car maybe-tail-gen)))
-                 (if (pair? (cdr maybe-tail-gen))
-                     (apply error "Too many arguments" unfold p f g seed maybe-tail-gen)
-                     (let recur ((seed seed))
-                       (if (p seed) (tail-gen seed)
-                           (cons (f seed) (recur (g seed)))))))
+               (let* ((prefix-last (drop x (- k 1)))
+                      (suffix (cdr prefix-last)))
+                 (set-cdr! prefix-last '())
+                 (values x suffix))))
+
+         (define (zip x . xs)
+           (apply map list x xs))
+
+         (define (unzip1 xs)
+           (map car xs))
+
+         (define (unzip2 xs)
+           (let unzip2 ((xs xs))
+             (if (null-list? xs)
+                 (values xs xs)
+                 (let ((x (car xs)))
+                   (receive (a b) (unzip2 (cdr xs))
+                            (values (cons (car x) a)
+                                    (cons (cadr x) b)))))))
+
+         (define (unzip3 xs)
+           (let unzip3 ((xs xs))
+             (if (null-list? xs)
+                 (values xs xs xs)
+                 (let ((x (car xs)))
+                   (receive (a b c) (unzip3 (cdr xs))
+                            (values (cons (car x) a)
+                                    (cons (cadr x) b)
+                                    (cons (caddr x) c)))))))
+
+         (define (unzip4 xs)
+           (let unzip4 ((xs xs))
+             (if (null-list? xs)
+                 (values xs xs xs xs)
+                 (let ((x (car xs)))
+                   (receive (a b c d) (unzip4 (cdr xs))
+                            (values (cons (car x) a)
+                                    (cons (cadr x) b)
+                                    (cons (caddr x) c)
+                                    (cons (cadddr x) d)))))))
+
+         (define (unzip5 xs)
+           (let unzip5 ((xs xs))
+             (if (null-list? xs)
+                 (values xs xs xs xs xs)
+                 (let ((x (car xs)))
+                   (receive (a b c d e) (unzip5 (cdr xs))
+                            (values (cons (car x) a)
+                                    (cons (cadr x) b)
+                                    (cons (caddr x) c)
+                                    (cons (cadddr x) d)
+                                    (cons (car (cddddr x)) e)))))))
+
+         (define (count satisfy? x . xs)
+           (if (pair? xs)
+               (let recur ((x x)
+                           (xs xs)
+                           (i 0))
+                 (if (null-list? x)
+                     i
+                     (receive (as ds) (%cars+cdrs xs)
+                       (if (null? as) i
+                           (recur (cdr x)
+                                  ds
+                                  (if (apply satisfy? (car x) as)
+                                      (+ i 1)
+                                      i))))))
+               (let recur ((x x)
+                           (i 0))
+                 (if (null-list? x)
+                     i
+                     (recur (cdr x)
+                            (if (satisfy? (car x))
+                                (+ i 1)
+                                i))))))
+
+         (define (fold f z x . xs)
+           (if (pair? xs)
+               (let recur ((xs (cons x xs))
+                           (ans z))
+                 (receive (cars+ans cdrs) (%cars+cdrs+ xs ans)
+                   (if (null? cars+ans)
+                       ans
+                       (recur cdrs (apply f cars+ans)))))
+               (let recur ((x x)
+                           (ans z))
+                 (if (null-list? x)
+                     ans
+                     (recur (cdr x)
+                           (f (car x) ans))))))
+
+         (define (unfold p f g seed . generate)
+           (if (pair? generate)
+               (let ((generate (car generate)))
+                 (let recur ((seed seed))
+                   (if (p seed)
+                       (generate seed)
+                       (cons (f seed)
+                             (recur (g seed))))))
                (let recur ((seed seed))
-                 (if (p seed) '()
-                     (cons (f seed) (recur (g seed)))))))
-
-         (define (pair-fold f zero lis1 . lists)
-           (if (pair? lists)
-               (let lp ((lists (cons lis1 lists)) (ans zero))
-                 (let ((tails (%cdrs lists)))
-                   (if (null? tails) ans
-                       (lp tails (apply f (append! lists (list ans)))))))
-
-               (let lp ((lis lis1) (ans zero))
-                 (if (null-list? lis) ans
-                     (let ((tail (cdr lis)))
-                       (lp tail (f lis ans)))))))
-
-         (define (reduce f ridentity lis)
-           (if (null-list? lis)
+                 (if (p seed)
+                     '()
+                     (cons (f seed)
+                           (recur (g seed)))))))
+
+         (define (pair-fold f z x . xs)
+           (if (pair? xs)
+               (let recur ((xs (cons x xs))
+                           (ans z))
+                 (let ((tails (%cdrs xs)))
+                   (if (null? tails)
+                       ans
+                       (recur tails (apply f (append! xs (list ans)))))))
+               (let recur ((x x)
+                           (ans z))
+                 (if (null-list? x)
+                     ans
+                     (let ((tail (cdr x)))
+                       (recur tail (f x ans)))))))
+
+         (define (reduce f ridentity x)
+           (if (null-list? x)
                ridentity
-               (fold f (car lis) (cdr lis))))
+               (fold f (car x) (cdr x))))
 
-         (define (fold-right f knil x . xs)
+         (define (fold-right f z x . xs)
+           (if (pair? xs)
+               (let recur ((xs (cons x xs)))
+                 (let ((cdrs (%cdrs xs)))
+                   (if (null? cdrs)
+                       z
+                       (apply f (%cars+ xs (recur cdrs))))))
+               (let recur ((xs x))
+                 (if (null-list? xs)
+                     z
+                     (let ((x (car xs)))
+                       (f x (recur (cdr xs))))))))
+
+         (define (unfold-right p f g seed . tail)
+           (let recur ((seed seed)
+                       (ans (if (pair? tail)
+                                (car tail)
+                                '())))
+             (if (p seed)
+                 ans
+                 (recur (g seed)
+                        (cons (f seed) ans)))))
+
+         (define (pair-fold-right f z x . xs)
            (if (pair? xs)
-               (letrec ((recur (lambda (lists)
-                                 ((lambda (cdrs)
-                                    (if (null? cdrs) knil
-                                        (apply f (%cars+ lists (recur cdrs)))))
-                                  (%cdrs lists)))))
-                 (recur (cons x xs)))
-               (letrec ((recur (lambda (x)
-                                 (if (null-list? x) knil
-                                     ((lambda (head)
-                                        (f head (recur (cdr x))))
-                                      (car x))))))
-                 (recur x))))
-
-         (define (unfold-right p f g seed . maybe-tail)
-           (let lp ((seed seed)
-                    (ans (if (pair? maybe-tail) (car maybe-tail) '())))
-             (if (p seed) ans
-                 (lp (g seed)
-                     (cons (f seed) ans)))))
-
-         (define (pair-fold-right f zero lis1 . lists)
-           (if (pair? lists)
-               (let recur ((lists (cons lis1 lists)))
-                 (let ((cdrs (%cdrs lists)))
-                   (if (null? cdrs) zero
-                       (apply f (append! lists (list (recur cdrs)))))))
-               (let recur ((lis lis1))
-                 (if (null-list? lis) zero (f lis (recur (cdr lis)))))))
-
-         (define (reduce-right f ridentity lis)
-           (if (null-list? lis) ridentity
-               (let recur ((head (car lis)) (lis (cdr lis)))
-                 (if (pair? lis)
-                     (f head (recur (car lis) (cdr lis)))
-                     head))))
-
-         (define (append-map f lis1 . lists)
-           (really-append-map append-map append f lis1 lists))
-
-         (define (append-map! f lis1 . lists)
-           (really-append-map append-map! append! f lis1 lists))
-
-         (define (really-append-map who appender f lis0 lists)
-           (if (pair? lists)
-               (receive (cars cdrs) (%cars+cdrs (cons lis1 lists))
-                        (if (null? cars) '()
-                            (let recur ((cars cars) (cdrs cdrs))
-                              (let ((vals (apply f cars)))
-                                (receive (cars2 cdrs2) (%cars+cdrs cdrs)
-                                         (if (null? cars2) vals
-                                             (appender vals (recur cars2 cdrs2))))))))
-               (if (null-list? lis1) '()
-                   (let recur ((elt (car lis1)) (rest (cdr lis1)))
-                     (let ((vals (f elt)))
-                       (if (null-list? rest) vals
-                           (appender vals (recur (car rest) (cdr rest)))))))))
-
-         (define (map! f lis1 . lists)
-           (if (pair? lists)
-               (let lp ((lis1 lis1) (lists lists))
-                 (if (not (null-list? lis1))
-                     (receive (heads tails) (%cars+cdrs/no-test lists)
-                              (set-car! lis1 (apply f (car lis1) heads))
-                              (lp (cdr lis1) tails))))
-               (pair-for-each (lambda (pair) (set-car! pair (f (car pair)))) lis1))
-           lis1)
-
-         (define (pair-for-each proc lis1 . lists)
-           (if (pair? lists)
-               (let lp ((lists (cons lis1 lists)))
-                 (let ((tails (%cdrs lists)))
+               (let recur ((xs (cons x xs)))
+                 (let ((cdrs (%cdrs xs)))
+                   (if (null? cdrs)
+                       z
+                       (apply f (append! xs (list (recur cdrs)))))))
+               (let recur ((x x))
+                 (if (null-list? x)
+                     z
+                     (f x (recur (cdr x)))))))
+
+         (define (reduce-right f ridentity xs)
+           (if (null-list? xs)
+               ridentity
+               (let reduce-right ((x (car xs))
+                                  (xs (cdr xs)))
+                 (if (pair? xs)
+                     (f x (reduce-right (car xs)
+                                        (cdr xs)))
+                     x))))
+
+         (define (append-map f x . xs)
+           (%append-map append-map append f x xs))
+
+         (define (append-map! f x . xs)
+           (%append-map append-map! append! f x xs))
+
+         (define (%append-map who appender f x xs)
+           (if (pair? xs)
+               (receive (cars cdrs) (%cars+cdrs (cons x xs))
+                 (if (null? cars)
+                     '()
+                     (let recur ((cars cars)
+                                 (cdrs cdrs))
+                       (let ((vals (apply f cars)))
+                         (receive (cars2 cdrs2) (%cars+cdrs cdrs)
+                           (if (null? cars2)
+                               vals
+                               (appender vals (recur cars2 cdrs2))))))))
+               (if (null-list? x)
+                   '()
+                   (let recur ((x (car x))
+                               (xs (cdr x)))
+                     (let ((vals (f x)))
+                       (if (null-list? xs)
+                           vals
+                           (appender vals
+                                     (recur (car xs)
+                                            (cdr xs)))))))))
+
+         (define (map! f x . xs)
+           (if (pair? xs)
+               (let recur ((x x)
+                           (xs xs))
+                 (if (not (null-list? x))
+                     (receive (heads tails) (%cars+cdrs/no-test xs)
+                       (set-car! x (apply f (car x) heads))
+                       (recur (cdr x)
+                              tails))))
+               (pair-for-each (lambda (pair)
+                                (set-car! pair (f (car pair))))
+                              x))
+           x)
+
+         (define (pair-for-each f x . xs)
+           (if (pair? xs)
+               (let recur ((xs (cons x xs)))
+                 (let ((tails (%cdrs xs)))
                    (if (pair? tails)
-                       (begin (apply proc lists)
-                              (lp tails)))))
-               (let lp ((lis lis1))
-                 (if (not (null-list? lis))
-                     (let ((tail (cdr lis)))
-                       (proc lis)
-                       (lp tail))))))
-
-         (define (filter-map f lis1 . lists)
-           (if (pair? lists)
-               (let recur ((lists (cons lis1 lists)))
-                 (receive (cars cdrs) (%cars+cdrs lists)
-                          (if (pair? cars)
-                              (cond ((apply f cars) => (lambda (x) (cons x (recur cdrs))))
-                                    (else (recur cdrs))) ; Tail call in this arm.
-                              '())))
-               (let recur ((lis lis1))
-                 (if (null-list? lis) lis
-                     (let ((tail (recur (cdr lis))))
-                       (cond ((f (car lis)) => (lambda (x) (cons x tail)))
+                       (begin (apply f xs)
+                              (recur tails)))))
+               (let recur ((x x))
+                 (if (not (null-list? x))
+                     (let ((tail (cdr x)))
+                       (f x)
+                       (recur tail))))))
+
+         (define (filter-map f x . xs)
+           (if (pair? xs)
+               (let recur ((xs (cons x xs)))
+                 (receive (cars cdrs) (%cars+cdrs xs)
+                   (if (pair? cars)
+                       (cond ((apply f cars) => (lambda (x) (cons x (recur cdrs))))
+                             (else (recur cdrs)))
+                       '())))
+               (let recur ((x x))
+                 (if (null-list? x) x
+                     (let ((tail (recur (cdr x))))
+                       (cond ((f (car x)) => (lambda (x) (cons x tail)))
                              (else tail)))))))
 
-         (define (map-in-order f lis1 . lists)
-           (if (pair? lists)
-               (let recur ((lists (cons lis1 lists)))
-                 (receive (cars cdrs) (%cars+cdrs lists)
-                          (if (pair? cars)
-                              (let ((x (apply f cars)))
-                                (cons x (recur cdrs)))
-                              '())))
-               (let recur ((lis lis1))
-                 (if (null-list? lis) lis
-                     (let ((tail (cdr lis))
-                           (x (f (car lis))))
+         (define (map-in-order f x . xs)
+           (if (pair? xs)
+               (let recur ((xs (cons x xs)))
+                 (receive (cars cdrs) (%cars+cdrs xs)
+                   (if (pair? cars)
+                       (let ((x (apply f cars)))
+                         (cons x (recur cdrs)))
+                       '())))
+               (let recur ((x x))
+                 (if (null-list? x) x
+                     (let ((tail (cdr x))
+                           (x (f (car x))))
                        (cons x (recur tail)))))))
 
-         (define (filter pred lis)
-           (let recur ((lis lis))
-             (if (null-list? lis) lis
-                 (let ((head (car lis))
-                       (tail (cdr lis)))
-                   (if (pred head)
+         (define (filter satisfy? x)
+           (let recur ((x x))
+             (if (null-list? x)
+                 x
+                 (let ((head (car x))
+                       (tail (cdr x)))
+                   (if (satisfy? head)
                        (let ((new-tail (recur tail)))
-                         (if (eq? tail new-tail) lis
+                         (if (eq? tail new-tail)
+                             x
                              (cons head new-tail)))
                        (recur tail))))))
 
-         ; (define (filter pred lis) ; Another version that shares longest tail.
-         ;   (receive (ans no-del?)
-         ;     (let recur ((l l))
-         ;       (if (null-list? l) (values l #t)
-         ;           (let ((x  (car l))
-         ;                 (tl (cdr l)))
-         ;             (if (pred x)
-         ;                 (receive (ans no-del?) (recur tl)
-         ;                   (if no-del?
-         ;                       (values l #t)
-         ;                       (values (cons x ans) #f)))
-         ;                 (receive (ans no-del?) (recur tl) ; Delete X.
-         ;                   (values ans #f))))))
-         ;     ans))
-
-         (define (partition pred lis)
-           (let recur ((lis lis))
-             (if (null-list? lis) (values lis lis) ; Use NOT-PAIR? to handle dotted lists.
-                 (let ((elt (car lis))
-                       (tail (cdr lis)))
-                   (receive (in out) (recur tail)
-                            (if (pred elt)
-                                (values (if (pair? out) (cons elt in) lis) out)
-                                (values in (if (pair? in) (cons elt out) lis))))))))
-
-         (define (remove satisfy? x)
-           (filter (lambda (y)
-                     (not (satisfy? y)))
-                   x))
-
-         ; Things are much simpler if you are willing to push N stack frames & do N
-         ; set-cdr! writes, where N is the length of the answer.
-         (define (filter! pred lis)
-           (let recur ((lis lis))
-             (if (pair? lis)
-                 (cond ((pred (car lis))
-                        (set-cdr! lis (recur (cdr lis)))
-                        lis)
-                       (else (recur (cdr lis))))
-                 lis)))
-
-         ; (define (filter! pred lis)
-         ;   (let lp ((ans lis))
-         ;     (cond ((null-list? ans) ans)
-         ;           ((not (pred (car ans))) (lp (cdr ans)))
-         ;           (else (letrec ((scan-in (lambda (prev lis)
-         ;                                     (if (pair? lis)
-         ;                                         (if (pred (car lis))
-         ;                                             (scan-in lis (cdr lis))
-         ;                                             (scan-out prev (cdr lis))))))
-         ;                          (scan-out (lambda (prev lis)
-         ;                                      (let lp ((lis lis))
-         ;                                        (if (pair? lis)
-         ;                                            (if (pred (car lis))
-         ;                                                (begin (set-cdr! prev lis)
-         ;                                                       (scan-in lis (cdr lis)))
-         ;                                                (lp (cdr lis)))
-         ;                                            (set-cdr! prev lis))))))
-         ;                   (scan-in ans (cdr ans))
-         ;                   ans)))))
-
-         (define (partition! pred lis)
-           (if (null-list? lis)
-               (values lis lis)
-               (letrec ((scan-in (lambda (in-prev out-prev lis)
-                                   (let lp ((in-prev in-prev) (lis lis))
-                                     (if (pair? lis)
-                                         (if (pred (car lis))
-                                             (lp lis (cdr lis))
-                                             (begin (set-cdr! out-prev lis)
-                                                    (scan-out in-prev lis (cdr lis))))
-                                         (set-cdr! out-prev lis)))))
-                        (scan-out (lambda (in-prev out-prev lis)
-                                    (let lp ((out-prev out-prev) (lis lis))
-                                      (if (pair? lis)
-                                          (if (pred (car lis))
-                                              (begin (set-cdr! in-prev lis)
-                                                     (scan-in lis out-prev (cdr lis)))
-                                              (lp lis (cdr lis)))
-                                          (set-cdr! in-prev lis))))))
-                 (if (pred (car lis))
-                     (let lp ((prev-l lis) (l (cdr lis)))
-                       (cond ((not (pair? l)) (values lis l))
-                             ((pred (car l)) (lp l (cdr l)))
+         (define (filter! satisfy? xs)
+           (let recur ((xs xs))
+             (if (pair? xs)
+                 (cond ((satisfy? (car xs))
+                        (set-cdr! xs (recur (cdr xs)))
+                        xs)
+                       (else (recur (cdr xs))))
+                 xs)))
+
+         (define (partition satisfy? xs)
+           (let recur ((xs xs))
+             (if (null-list? xs)
+                 (values xs xs)
+                 (let ((x (car xs)))
+                   (receive (a b) (recur (cdr xs))
+                     (if (satisfy? x)
+                         (values (if (pair? b)
+                                     (cons x a)
+                                     xs)
+                                 b)
+                         (values a
+                                 (if (pair? a)
+                                     (cons x b)
+                                     xs))))))))
+
+         (define (partition! satisfy? xs)
+           (if (null-list? xs)
+               (values xs xs)
+               (letrec ((scan-in (lambda (in-prev out-prev xs)
+                                   (let recur ((in-prev in-prev)
+                                               (xs xs))
+                                     (if (pair? xs)
+                                         (if (satisfy? (car xs))
+                                             (recur xs (cdr xs))
+                                             (begin (set-cdr! out-prev xs)
+                                                    (scan-out in-prev xs (cdr xs))))
+                                         (set-cdr! out-prev xs)))))
+                        (scan-out (lambda (in-prev out-prev xs)
+                                    (let recur ((out-prev out-prev)
+                                                (xs xs))
+                                      (if (pair? xs)
+                                          (if (satisfy? (car xs))
+                                              (begin (set-cdr! in-prev xs)
+                                                     (scan-in xs out-prev (cdr xs)))
+                                              (recur xs (cdr xs)))
+                                          (set-cdr! in-prev xs))))))
+                 (if (satisfy? (car xs))
+                     (let recur ((prev-l xs)
+                                 (l (cdr xs)))
+                       (cond ((not (pair? l))
+                              (values xs l))
+                             ((satisfy? (car l))
+                              (recur l (cdr l)))
                              (else (scan-out prev-l l (cdr l))
-                                   (values lis l))))
-                     (let lp ((prev-l lis) (l (cdr lis)))
-                       (cond ((not (pair? l)) (values l lis))
-                             ((pred (car l))
+                                   (values xs l))))
+                     (let recur ((prev-l xs)
+                                 (l (cdr xs)))
+                       (cond ((not (pair? l))
+                              (values l xs))
+                             ((satisfy? (car l))
                               (scan-in l prev-l (cdr l))
-                              (values l lis))
-                             (else (lp l (cdr l)))))))))
+                              (values l xs))
+                             (else (recur l (cdr l)))))))))
+
+         (define (remove satisfy? xs)
+           (filter (lambda (x)
+                     (not (satisfy? x)))
+                   xs))
 
-         (define (remove! satisfy? x)
-           (filter! (lambda (y) (not (satisfy? y))) x))
+         (define (remove! satisfy? xs)
+           (filter! (lambda (x)
+                      (not (satisfy? x)))
+                    xs))
 
-         (define (find pred list)
-           (cond ((find-tail pred list) => car)
+         (define (find satisfy? xs)
+           (cond ((find-tail satisfy? xs) => car)
                  (else #f)))
 
-         (define (find-tail pred list)
-           (let lp ((list list))
-             (and (not (null-list? list))
-                  (if (pred (car list)) list
-                      (lp (cdr list))))))
-
-         (define (any pred lis1 . lists)
-           (if (pair? lists)
-               (receive (heads tails) (%cars+cdrs (cons lis1 lists))
-                        (and (pair? heads)
-                             (let lp ((heads heads) (tails tails))
-                               (receive (next-heads next-tails) (%cars+cdrs tails)
-                                        (if (pair? next-heads)
-                                            (or (apply pred heads) (lp next-heads next-tails))
-                                            (apply pred heads))))))
-               (and (not (null-list? lis1))
-                    (let lp ((head (car lis1)) (tail (cdr lis1)))
+         (define (find-tail satisfy? xs)
+           (let recur ((xs xs))
+             (and (not (null-list? xs))
+                  (if (satisfy? (car xs))
+                      xs
+                      (recur (cdr xs))))))
+
+         (define (any satisfy? x . xs)
+           (if (pair? xs)
+               (receive (cars cdrs) (%cars+cdrs (cons x xs))
+                 (and (pair? cars)
+                      (let recur ((cars cars)
+                                  (cdrs cdrs))
+                        (receive (next-cars next-cdrs) (%cars+cdrs cdrs)
+                          (if (pair? next-cars)
+                              (or (apply satisfy? cars)
+                                  (recur next-cars
+                                         next-cdrs))
+                              (apply satisfy? cars))))))
+               (and (not (null-list? x))
+                    (let recur ((head (car x))
+                                (tail (cdr x)))
                       (if (null-list? tail)
-                          (pred head)
-                          (or (pred head) (lp (car tail) (cdr tail))))))))
-
-         (define (every pred lis1 . lists)
-           (if (pair? lists)
-               (receive (heads tails) (%cars+cdrs (cons lis1 lists))
-                        (or (not (pair? heads))
-                            (let lp ((heads heads) (tails tails))
-                              (receive (next-heads next-tails) (%cars+cdrs tails)
-                                       (if (pair? next-heads)
-                                           (and (apply pred heads) (lp next-heads next-tails))
-                                           (apply pred heads))))))
-               (or (null-list? lis1)
-                   (let lp ((head (car lis1))  (tail (cdr lis1)))
+                          (satisfy? head)
+                          (or (satisfy? head)
+                              (recur (car tail)
+                                     (cdr tail))))))))
+
+         (define (every satisfy? x . xs)
+           (if (pair? xs)
+               (receive (heads tails) (%cars+cdrs (cons x xs))
+                 (or (not (pair? heads))
+                     (let recur ((heads heads)
+                                 (tails tails))
+                       (receive (next-heads next-tails) (%cars+cdrs tails)
+                         (if (pair? next-heads)
+                             (and (apply satisfy? heads)
+                                  (recur next-heads next-tails))
+                             (apply satisfy? heads))))))
+               (or (null-list? x)
+                   (let recur ((head (car x))
+                               (tail (cdr x)))
                      (if (null-list? tail)
-                         (pred head)
-                         (and (pred head) (lp (car tail) (cdr tail))))))))
-
-         (define (list-index pred lis1 . lists)
-           (if (pair? lists)
-               (let lp ((lists (cons lis1 lists)) (n 0))
-                 (receive (heads tails) (%cars+cdrs lists)
-                          (and (pair? heads)
-                               (if (apply pred heads) n
-                                   (lp tails (+ n 1))))))
-               (let lp ((lis lis1) (n 0))
-                 (and (not (null-list? lis))
-                      (if (pred (car lis)) n (lp (cdr lis) (+ n 1)))))))
-
-         (define (take-while pred lis)
-           (let recur ((lis lis))
-             (if (null-list? lis) '()
-                 (let ((x (car lis)))
-                   (if (pred x)
-                       (cons x (recur (cdr lis)))
-                       '())))))
+                         (satisfy? head)
+                         (and (satisfy? head)
+                              (recur (car tail)
+                                     (cdr tail))))))))
 
-         (define (drop-while pred lis)
-           (let lp ((lis lis))
-             (if (null-list? lis) '()
-                 (if (pred (car lis))
-                     (lp (cdr lis))
-                     lis))))
+         (define (list-index satisfy? x . xs)
+           (if (pair? xs)
+               (let recur ((xs (cons x xs))
+                           (n 0))
+                 (receive (heads tails) (%cars+cdrs xs)
+                   (and (pair? heads)
+                        (if (apply satisfy? heads)
+                            n
+                            (recur tails (+ n 1))))))
+               (let recur ((xs x)
+                           (n 0))
+                 (and (not (null-list? xs))
+                      (if (satisfy? (car xs))
+                          n
+                          (recur (cdr xs)
+                                 (+ n 1)))))))
+
+         (define (take-while satisfy? xs)
+           (let recur ((xs xs))
+             (if (null-list? xs)
+                 '()
+                 (let ((x (car xs)))
+                   (if (satisfy? x)
+                       (cons x (recur (cdr xs)))
+                       '())))))
 
-         (define (take-while! pred lis)
-           (if (or (null-list? lis) (not (pred (car lis)))) '()
-               (begin (let lp ((prev lis) (rest (cdr lis)))
+         (define (take-while! satisfy? xs)
+           (if (or (null-list? xs)
+                   (not (satisfy? (car xs))))
+               '()
+               (begin (let recur ((prev xs)
+                                  (rest (cdr xs)))
                         (if (pair? rest)
                             (let ((x (car rest)))
-                              (if (pred x) (lp rest (cdr rest))
+                              (if (satisfy? x)
+                                  (recur rest (cdr rest))
                                   (set-cdr! prev '())))))
-                      lis)))
-
-         (define (span pred lis)
-           (let recur ((lis lis))
-             (if (null-list? lis) (values '() '())
-                 (let ((x (car lis)))
-                   (if (pred x)
-                       (receive (prefix suffix) (recur (cdr lis))
-                                (values (cons x prefix) suffix))
-                       (values '() lis))))))
+                      xs)))
+
+         (define (drop-while satisfy? xs)
+           (let recur ((xs xs))
+             (if (null-list? xs)
+                 '()
+                 (if (satisfy? (car xs))
+                     (recur (cdr xs))
+                     xs))))
+
+         (define (span satisfy? xs)
+           (let recur ((xs xs))
+             (if (null-list? xs)
+                 (values '() '())
+                 (let ((x (car xs)))
+                   (if (satisfy? x)
+                       (receive (a b) (recur (cdr xs))
+                         (values (cons x a) b))
+                       (values '() xs))))))
+
+         (define (span! satisfy? xs)
+           (if (or (null-list? xs)
+                   (not (satisfy? (car xs))))
+               (values '() xs)
+               (let ((suffix (let recur ((prev xs)
+                                         (rest (cdr xs)))
+                               (if (null-list? rest)
+                                   rest
+                                   (let ((x (car rest)))
+                                     (if (satisfy? x)
+                                         (recur rest (cdr rest))
+                                         (begin (set-cdr! prev '())
+                                                rest)))))))
+                 (values xs suffix))))
 
          (define (break break? x)
            (span (lambda (x)
                    (not (break? x)))
                  x))
 
-         (define (span! pred lis)
-           (if (or (null-list? lis) (not (pred (car lis)))) (values '() lis)
-               (let ((suffix (let lp ((prev lis) (rest (cdr lis)))
-                               (if (null-list? rest) rest
-                                   (let ((x (car rest)))
-                                     (if (pred x) (lp rest (cdr rest))
-                                         (begin (set-cdr! prev '())
-                                                rest)))))))
-                 (values lis suffix))))
-
          (define (break! break? x)
-           (span! (lambda (x) (not (break? x))) x))
-
-         (define (delete x lis . maybe-=)
-           (let ((= (if (pair? maybe-=) (car maybe-=) equal?)))
-             (filter (lambda (y) (not (= x y))) lis)))
-
-         (define (delete-duplicates lis . maybe-=)
-           (let ((elt= (if (pair? maybe-=) (car maybe-=) equal?)))
-             (let recur ((lis lis))
-               (if (null-list? lis) lis
-                   (let* ((x (car lis))
-                          (tail (cdr lis))
-                          (new-tail (recur (delete x tail elt=))))
-                     (if (eq? tail new-tail) lis (cons x new-tail)))))))
-
-         (define (delete! x lis . maybe-=)
-           (let ((= (if (pair? maybe-=) (car maybe-=) equal?)))
-             (filter! (lambda (y) (not (= x y))) lis)))
-
-         (define (delete-duplicates! lis maybe-=)
-           (let ((elt= (if (pair? maybe-=) (car maybe-=) equal?)))
-             (let recur ((lis lis))
-               (if (null-list? lis) lis
-                   (let* ((x (car lis))
-                          (tail (cdr lis))
-                          (new-tail (recur (delete! x tail elt=))))
-                     (if (eq? tail new-tail) lis (cons x new-tail)))))))
-
-         (define (alist-delete key alist . maybe-=)
-           (let ((= (if (pair? maybe-=) (car maybe-=) equal?)))
-             (filter (lambda (elt) (not (= key (car elt)))) alist)))
-
-         (define (alist-delete! key alist . maybe-=)
-           (let ((= (if (pair? maybe-=) (car maybe-=) equal?)))
-             (filter! (lambda (elt) (not (= key (car elt)))) alist)))
-
-         (define (lset<= = . lists)
-           (or (not (pair? lists)) ; 0-ary case
-               (let lp ((s1 (car lists)) (rest (cdr lists)))
-                 (or (not (pair? rest))
-                     (let ((s2 (car rest))  (rest (cdr rest)))
-                       (and (or (eq? s2 s1) ; Fast path
-                                (%lset2<= = s1 s2)) ; Real test
-                            (lp s2 rest)))))))
-
-         (define (lset= = . lists)
-           (or (not (pair? lists)) ; 0-ary case
-               (let lp ((s1 (car lists)) (rest (cdr lists)))
-                 (or (not (pair? rest))
-                     (let ((s2   (car rest))
-                           (rest (cdr rest)))
-                       (and (or (eq? s1 s2) ; Fast path
-                                (and (%lset2<= = s1 s2) (%lset2<= = s2 s1))) ; Real test
-                            (lp s2 rest)))))))
-
-         (define (lset-adjoin = lis . elts)
-           (fold (lambda (elt ans) (if (member elt ans =) ans (cons elt ans)))
-                 lis elts))
-
-         (define (lset-union = . lists)
-           (reduce (lambda (lis ans) ; Compute ANS + LIS.
-                     (cond ((null? lis) ans) ; Don't copy any lists
-                           ((null? ans) lis) ; if we don't have to.
-                           ((eq? lis ans) ans)
-                           (else
-                             (fold (lambda (elt ans) (if (any (lambda (x) (= x elt)) ans)
-                                                         ans
-                                                         (cons elt ans)))
-                                   ans lis))))
-                   '() lists))
-
-         (define (lset-union! = . lists)
-           (reduce (lambda (lis ans) ; Splice new elts of LIS onto the front of ANS.
-                     (cond ((null? lis) ans) ; Don't copy any lists
-                           ((null? ans) lis) ; if we don't have to.
-                           ((eq? lis ans) ans)
-                           (else
-                             (pair-fold (lambda (pair ans)
-                                          (let ((elt (car pair)))
-                                            (if (any (lambda (x) (= x elt)) ans)
-                                                ans
-                                                (begin (set-cdr! pair ans) pair))))
-                                        ans lis))))
-                   '() lists))
-
-         (define (lset-intersection = lis1 . lists)
-           (let ((lists (delete lis1 lists eq?))) ; Throw out any LIS1 vals.
-             (cond ((any null-list? lists) '()) ; Short cut
-                   ((null? lists) lis1) ; Short cut
+           (span! (lambda (x)
+                    (not (break? x)))
+                  x))
+
+         (define (delete x xs . x=?)
+           (let ((x=? (if (pair? x=?)
+                          (car x=?)
+                          equal?)))
+             (filter (lambda (y)
+                       (not (x=? x y)))
+                     xs)))
+
+         (define (delete! x xs . x=?)
+           (let ((x=? (if (pair? x=?)
+                          (car x=?)
+                          equal?)))
+             (filter! (lambda (y)
+                        (not (x=? x y)))
+                      xs)))
+
+         (define (delete-duplicates xs . x=?)
+           (let ((x=? (if (pair? x=?)
+                          (car x=?)
+                          equal?)))
+             (let recur ((x:xs xs))
+               (if (null-list? x:xs)
+                   '()
+                   (let* ((x (car x:xs))
+                          (xs (cdr x:xs))
+                          (ys (recur (delete x xs x=?))))
+                     (if (eq? xs ys)
+                         x:xs
+                         (cons x ys)))))))
+
+         (define (delete-duplicates! xs . x=?)
+           (let ((x=? (if (pair? x=?)
+                          (car x=?)
+                          equal?)))
+             (let recur ((x:xs xs))
+               (if (null-list? x:xs)
+                   '()
+                   (let* ((x (car x:xs))
+                          (xs (cdr x:xs))
+                          (ys (recur (delete! x xs x=?))))
+                     (if (eq? xs ys)
+                         x:xs
+                         (cons x ys)))))))
+
+         (define (alist-delete key alist . key=?)
+           (let ((key=? (if (pair? key=?)
+                            (car key=?)
+                            equal?)))
+             (filter (lambda (x)
+                       (not (key=? key (car x))))
+                     alist)))
+
+         (define (alist-delete! key alist . key=?)
+           (let ((key=? (if (pair? key=?)
+                        (car key=?)
+                        equal?)))
+             (filter! (lambda (x)
+                        (not (key=? key (car x))))
+                      alist)))
+
+         (define (lset<= x=? . xss)
+           (or (not (pair? xss))
+               (let recur ((xs (car xss))
+                           (xss (cdr xss)))
+                 (or (not (pair? xss))
+                     (let ((ys (car xss))
+                           (xss (cdr xss)))
+                       (and (or (eq? xs ys)
+                                (%lset2<= x=? xs ys))
+                            (recur ys xss)))))))
+
+         (define (lset= x=? . xss)
+           (or (not (pair? xss))
+               (let recur ((xs (car xss))
+                           (xss (cdr xss)))
+                 (or (not (pair? xss))
+                     (let ((ys (car xss))
+                           (xss (cdr xss)))
+                       (and (or (eq? xs ys)
+                                (and (%lset2<= x=? xs ys)
+                                     (%lset2<= x=? ys xs)))
+                            (recur ys xss)))))))
+
+         (define (lset-adjoin x=? xs . ys)
+           (fold (lambda (y xs)
+                   (if (member y xs x=?)
+                       xs
+                       (cons y xs)))
+                 xs
+                 ys))
+
+         (define (lset-union x=? . xss)
+           (reduce (lambda (xs ys)
+                     (cond ((null? xs) ys)
+                           ((null? ys) xs)
+                           ((eq? xs ys) ys)
+                           (else (fold (lambda (x ys)
+                                         (if (any (lambda (y)
+                                                    (x=? x y))
+                                                  ys)
+                                             ys
+                                             (cons x ys)))
+                                       ys
+                                       xs))))
+                   '()
+                   xss))
+
+         (define (lset-union! x=? . xss)
+           (reduce (lambda (xs ys)
+                     (cond ((null? xs) ys)
+                           ((null? ys) xs)
+                           ((eq? xs ys) ys)
+                           (else (pair-fold (lambda (x:xs ys)
+                                              (let ((x (car x:xs)))
+                                                (if (any (lambda (y)
+                                                           (x=? x y))
+                                                         ys)
+                                                    ys
+                                                    (begin (set-cdr! x:xs ys)
+                                                           x:xs))))
+                                            ys
+                                            xs))))
+                   '()
+                   xss))
+
+         (define (lset-intersection x=? xs . xss)
+           (let ((xss (delete xs xss eq?)))
+             (cond ((any null-list? xss) '())
+                   ((null? xss) xs)
                    (else (filter (lambda (x)
-                                   (every (lambda (lis) (member x lis =)) lists))
-                                 lis1)))))
-
-         (define (lset-intersection! = lis1 . lists)
-           (let ((lists (delete lis1 lists eq?))) ; Throw out any LIS1 vals.
-             (cond ((any null-list? lists) '()) ; Short cut
-                   ((null? lists)          lis1) ; Short cut
+                                   (every (lambda (xs)
+                                            (member x xs x=?))
+                                          xss))
+                                 xs)))))
+
+         (define (lset-intersection! x=? xs . xss)
+           (let ((xss (delete xs xss eq?)))
+             (cond ((any null-list? xss) '())
+                   ((null? xss) xs)
                    (else (filter! (lambda (x)
-                                    (every (lambda (lis) (member x lis =)) lists))
-                                  lis1)))))
-
-         (define (lset-difference = lis1 . lists)
-           (let ((lists (filter pair? lists))) ; Throw out empty lists.
-             (cond ((null? lists)     lis1) ; Short cut
-                   ((memq lis1 lists) '()) ; Short cut
+                                    (every (lambda (xs)
+                                             (member x xs x=?))
+                                           xss))
+                                  xs)))))
+
+         (define (lset-difference x=? xs . xss)
+           (let ((xss (filter pair? xss)))
+             (cond ((null? xss) xs)
+                   ((memq xs xss) '())
                    (else (filter (lambda (x)
-                                   (every (lambda (lis) (not (member x lis =)))
-                                          lists))
-                                 lis1)))))
-
-         (define (lset-difference! = lis1 . lists)
-           (let ((lists (filter pair? lists))) ; Throw out empty lists.
-             (cond ((null? lists)     lis1) ; Short cut
-                   ((memq lis1 lists) '()) ; Short cut
+                                   (every (lambda (xs)
+                                            (not (member x xs x=?)))
+                                          xss))
+                                 xs)))))
+
+         (define (lset-difference! x=? xs . xss)
+           (let ((xss (filter pair? xss)))
+             (cond ((null? xss) xs)
+                   ((memq xs xss) '())
                    (else (filter! (lambda (x)
-                                    (every (lambda (lis) (not (member x lis =)))
-                                           lists))
-                                  lis1)))))
-
-         (define (lset-xor = . lists)
-           (reduce (lambda (b a) ; Compute A xor B:
-                     ;; Note that this code relies on the constant-time
-                     ;; short-cuts provided by LSET-DIFF+INTERSECTION,
-                     ;; LSET-DIFFERENCE & APPEND to provide constant-time short
-                     ;; cuts for the cases A = (), B = (), and A eq? B. It takes
-                     ;; a careful case analysis to see it, but it's carefully
-                     ;; built in.
-
-                     ;; Compute a-b and a^b, then compute b-(a^b) and
-                     ;; cons it onto the front of a-b.
-                     (receive (a-b a-int-b) (lset-diff+intersection = a b)
-                              (cond ((null? a-b) (lset-difference = b a))
-                                    ((null? a-int-b) (append b a))
-                                    (else (fold (lambda (xb ans)
-                                                  (if (member xb a-int-b =) ans (cons xb ans)))
-                                                a-b
-                                                b)))))
-                   '() lists))
-
-         (define (lset-xor! = . lists)
-           (reduce (lambda (b a) ; Compute A xor B:
-                     ;; Note that this code relies on the constant-time
-                     ;; short-cuts provided by LSET-DIFF+INTERSECTION,
-                     ;; LSET-DIFFERENCE & APPEND to provide constant-time short
-                     ;; cuts for the cases A = (), B = (), and A eq? B. It takes
-                     ;; a careful case analysis to see it, but it's carefully
-                     ;; built in.
-
-                     ;; Compute a-b and a^b, then compute b-(a^b) and
-                     ;; cons it onto the front of a-b.
-                     (receive (a-b a-int-b) (lset-diff+intersection! = a b)
-                              (cond ((null? a-b) (lset-difference! = b a))
-                                    ((null? a-int-b) (append! b a))
-                                    (else (pair-fold (lambda (b-pair ans)
-                                                       (if (member (car b-pair) a-int-b =) ans
-                                                           (begin (set-cdr! b-pair ans) b-pair)))
-                                                     a-b
-                                                     b)))))
-                   '() lists))
-
-         (define (lset-diff+intersection = lis1 . lists)
-           (cond ((every null-list? lists) (values lis1 '())) ; Short cut
-                 ((memq lis1 lists) (values '() lis1)) ; Short cut
-                 (else (partition (lambda (elt)
-                                    (not (any (lambda (lis) (member elt lis =))
-                                              lists)))
-                                  lis1))))
-
-         (define (lset-diff+intersection! = lis1 . lists)
-           (cond ((every null-list? lists) (values lis1 '())) ; Short cut
-                 ((memq lis1 lists) (values '() lis1)) ; Short cut
-                 (else (partition! (lambda (elt)
-                                     (not (any (lambda (lis) (member elt lis =))
-                                               lists)))
-                                   lis1))))
-         )
-
-  (begin ; Return (map cdr lists).
-         ; However, if any element of LISTS is empty, just abort and return '().
-         (define (%cdrs xs)
+                                    (every (lambda (xs)
+                                             (not (member x xs x=?)))
+                                           xss))
+                                  xs)))))
+
+         (define (lset-xor x=? . xss)
+           (reduce (lambda (b a)
+                     (receive (a-b a^b) (lset-diff+intersection x=? a b)
+                       (cond ((null? a-b) (lset-difference x=? b a))
+                             ((null? a^b) (append b a))
+                             (else (fold (lambda (x xs)
+                                           (if (member x a^b x=?)
+                                               xs
+                                               (cons x xs)))
+                                         a-b
+                                         b)))))
+                   '()
+                   xss))
+
+         (define (lset-xor! x=? . xss)
+           (reduce (lambda (b a)
+                     (receive (a-b a^b) (lset-diff+intersection! x=? a b)
+                       (cond ((null? a-b) (lset-difference! x=? b a))
+                             ((null? a^b) (append! b a))
+                             (else (pair-fold (lambda (x:xs ys)
+                                                (if (member (car x:xs) a^b x=?)
+                                                    ys
+                                                    (begin (set-cdr! x:xs ys)
+                                                           x:xs)))
+                                              a-b
+                                              b)))))
+                   '()
+                   xss))
+
+         (define (lset-diff+intersection x=? xs . xss)
+           (cond ((every null-list? xss)
+                  (values xs '()))
+                 ((memq xs xss)
+                  (values '() xs))
+                 (else (partition (lambda (x)
+                                    (not (any (lambda (xs)
+                                                (member x xs x=?))
+                                              xss)))
+                                  xs))))
+
+         (define (lset-diff+intersection! x=? xs . xss)
+           (cond ((every null-list? xss)
+                  (values xs '()))
+                 ((memq xs xss)
+                  (values '() xs))
+                 (else (partition! (lambda (x)
+                                     (not (any (lambda (xs)
+                                                 (member x xs x=?))
+                                               xss)))
+                                   xs)))))
+
+  (begin (define (%cdrs xss)
            (call-with-current-continuation!
              (lambda (abort)
-               (letrec ((recur (lambda (xs)
-                                 (if (pair? xs)
-                                     ((lambda (x)
-                                        (if (null-list? x)
-                                            (abort '())
-                                            (cons (cdr x)
-                                                  (recur (cdr xs)))))
-                                      (car xs))
-                                     '()))))
-                 (recur xs)))))
-
-         (define (%cars+ lists last-elt) ; (append! (map car lists) (list last-elt))
-           (letrec ((recur (lambda (lists)
-                             (if (pair? lists)
-                                 (cons (caar lists)
-                                       (recur (cdr lists)))
-                                 (list last-elt)))))
-             (recur lists)))
-
-         (define (%cars+cdrs lists)
+               (let recur ((xss xss))
+                 (if (pair? xss)
+                     (let ((xs (car xss)))
+                       (if (null-list? xs)
+                           (abort '())
+                           (cons (cdr xs)
+                                 (recur (cdr xss)))))
+                     '())))))
+
+         (define (%cars+ xss cars)
+           (let recur ((xss xss))
+             (if (pair? xss)
+                 (cons (caar xss)
+                       (recur (cdr xss)))
+                 (list cars))))
+
+         (define (%cars+cdrs xss)
            (call-with-current-continuation!
              (lambda (abort)
-               (let recur ((lists lists))
-                 (if (pair? lists)
-                     (receive (list other-lists) (car+cdr lists)
-                              (if (null-list? list) (abort '() '()) ; LIST is empty -- bail out
-                                  (receive (a d) (car+cdr list)
-                                           (receive (cars cdrs) (recur other-lists)
-                                                    (values (cons a cars) (cons d cdrs))))))
-                     (values '() '()))))))
-
-         (define (%cars+cdrs+ lists cars-final)
+               (let recur ((xss xss))
+                 (if (pair? xss)
+                     (receive (xs xss) (car+cdr xss)
+                       (if (null-list? xs)
+                           (abort '()
+                                  '())
+                           (receive (a d) (car+cdr xs)
+                             (receive (cars cdrs) (recur xss)
+                               (values (cons a cars)
+                                       (cons d cdrs))))))
+                     (values '()
+                             '()))))))
+
+         (define (%cars+cdrs+ xss cars)
            (call-with-current-continuation!
              (lambda (abort)
-               (let recur ((lists lists))
-                 (if (pair? lists)
-                     (receive (list other-lists) (car+cdr lists)
-                              (if (null-list? list) (abort '() '()) ; LIST is empty -- bail out
-                                  (receive (a d) (car+cdr list)
-                                           (receive (cars cdrs) (recur other-lists)
-                                                    (values (cons a cars) (cons d cdrs))))))
-                     (values (list cars-final) '()))))))
-
-         (define (%cars+cdrs/no-test lists)
-           (let recur ((lists lists))
-             (if (pair? lists)
-                 (receive (list other-lists) (car+cdr lists)
-                          (receive (a d) (car+cdr list)
-                                   (receive (cars cdrs) (recur other-lists)
-                                            (values (cons a cars) (cons d cdrs)))))
-                 (values '() '()))))
-
-         (define (%lset2<= = lis1 lis2)
-           (every (lambda (x) (member x lis2 =)) lis1))))
+               (let recur ((xss xss))
+                 (if (pair? xss)
+                     (receive (xs xss) (car+cdr xss)
+                       (if (null-list? xs)
+                           (abort '()
+                                  '())
+                           (receive (a d) (car+cdr xs)
+                             (receive (cars cdrs) (recur xss)
+                               (values (cons a cars)
+                                       (cons d cdrs))))))
+                     (values (list cars)
+                             '()))))))
+
+         (define (%cars+cdrs/no-test xss)
+           (let recur ((xss xss))
+             (if (pair? xss)
+                 (receive (xs xss) (car+cdr xss)
+                   (receive (a d) (car+cdr xs)
+                     (receive (cars cdrs) (recur xss)
+                       (values (cons a cars)
+                               (cons d cdrs)))))
+                 (values '()
+                         '()))))
+
+         (define (%lset2<= x=? xs ys)
+           (every (lambda (x)
+                    (member x ys x=?))
+                  xs))))
diff --git a/test/srfi-1.ss b/test/srfi-1.ss
index 32ec9812b..4d1a3290b 100644
--- a/test/srfi-1.ss
+++ b/test/srfi-1.ss
@@ -1,20 +1,13 @@
 (import (scheme base)
+        (scheme cxr)
         (scheme process-context)
-        (only (srfi 1)
-              xcons cons* list-tabulate circular-list iota
-              circular-list? dotted-list? not-pair? null-list?
-              list=
-              first second third fourth fifth sixth seventh eighth ninth tenth
-              take take! drop take-right drop-right drop-right!
-              split-at split-at!
-              last last-pair
-              length+
-              append!
-              reverse!
-              concatenate concatenate!
-              append-reverse append-reverse!
-              alist-cons alist-copy
-              )
+        (scheme write)
+        (except (srfi 1)
+          cons list make-list list-copy pair? null? car cdr caar cadr cdar cddr
+          caaar caadr cadar caddr cdaar cdadr cddar cdddr caaaar caaadr caadar
+          caaddr cadaar cadadr caddar cadddr cdaaar cdaadr cdadar cdaddr cddaar
+          cddadr cdddar cddddr list-ref length append reverse map for-each memq
+          memv member assq assv assoc set-car! set-cdr!)
         (srfi 78))
 
 (check (cons 'a 'b) => '(a . b))
@@ -27,9 +20,13 @@
 (check (cons* 'a 'b) => '(a . b))
 (check (cons* 'a 'b 'c) => '(a b . c))
 
+(check (make-list 2 'a) => '(a a))
+
 (check (list-tabulate 4 (lambda (x) x)) => '(0 1 2 3))
 (check (list-tabulate 4 number->string) => '("0" "1" "2" "3"))
 
+(check (list-copy '(a b c)) => '(a b c))
+
 (check (circular-list 'a) => '#1=(a . #1#))
 (check (circular-list 'a 'b) => '#1=(a b . #1#))
 (check (circular-list 'a 'b 'c) => '#1=(a b c . #1#))
@@ -37,6 +34,25 @@
 (check (iota 5) => '(0 1 2 3 4))
 (check (iota 5 0 -0.1) (=> (lambda (x y) (list= = x y))) '(0 -0.1 -0.2 -0.3 -0.4))
 
+(check (pair? 'a) => #f)
+(check (pair? '(a . b)) => #t)
+(check (pair? '(a b . c)) => #t)
+(check (pair? '(a b c)) => #t)
+
+(check (null? '()) => #t)
+(check (null? '(a)) => #f)
+(check (null? '(a . b)) => #f)
+(check (null? '(a b . c)) => #f)
+(check (null? 'a) => #f)
+(check (null? 1) => #f)
+
+(check (proper-list? '()) => #t)
+(check (proper-list? '(a . b)) => #f)
+(check (proper-list? '(a b . c)) => #f)
+(check (proper-list? '(a b c)) => #t)
+(check (proper-list? 'a) => #f)
+(check (proper-list? 1) => #f)
+
 (check (circular-list? '(a b c)) => #f)
 (check (circular-list? '#1=(a b c . #1#)) => #t)
 
@@ -53,6 +69,50 @@
 (check (null-list? '(a b c)) => #f)
 (check (null-list? '#1=(a b c . #1#)) => #f)
 
+(check (list= eq? '(a b c) '(a b c)) => #t)
+(check (list= eq? '(a b c) '(a B c)) => #f)
+(check (list= eqv? '(1 2 3) '(1.0 2.0 3.0)) => #f)
+(check (list= =    '(1 2 3) '(1.0 2.0 3.0)) => #t)
+(check (list= eqv?   '((a b) (c d) (e f)) '((a b) (c d) (e f))) => #f)
+(check (list= equal? '((a b) (c d) (e f)) '((a b) (c d) (e f))) => #t)
+
+(check (car    '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => '(((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda))
+(check (cdr    '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => '(((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd))
+(check (caar   '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => '((aaaa . daaa) adaa . ddaa))
+(check (cadr   '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => '((aaad . daad) adad . ddad))
+(check (cdar   '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => '((aada . dada) adda . ddda))
+(check (cddr   '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => '((aadd . dadd) addd . dddd))
+(check (caaar  '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => '(aaaa . daaa))
+(check (caadr  '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => '(aaad . daad))
+(check (cadar  '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => '(aada . dada))
+(check (caddr  '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => '(aadd . dadd))
+(check (cdaar  '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => '(adaa . ddaa))
+(check (cdadr  '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => '(adad . ddad))
+(check (cddar  '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => '(adda . ddda))
+(check (cdddr  '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => '(addd . dddd))
+(check (caaaar '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => 'aaaa)
+(check (caaadr '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => 'aaad)
+(check (caadar '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => 'aada)
+(check (caaddr '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => 'aadd)
+(check (cadaar '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => 'adaa)
+(check (cadadr '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => 'adad)
+(check (caddar '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => 'adda)
+(check (cadddr '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => 'addd)
+(check (cdaaar '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => 'daaa)
+(check (cdaadr '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => 'daad)
+(check (cdadar '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => 'dada)
+(check (cdaddr '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => 'dadd)
+(check (cddaar '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => 'ddaa)
+(check (cddadr '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => 'ddad)
+(check (cdddar '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => 'ddda)
+(check (cddddr '((((aaaa . daaa) adaa . ddaa) (aada . dada) adda . ddda) ((aaad . daad) adad . ddad) (aadd . dadd) addd . dddd)) => 'dddd)
+
+(let ((x '(1 2 3 4 5 6 7 8 9 10)))
+  (let recurse ((i 0))
+    (if (< i (length x))
+        (begin (check (list-ref x i) => (+ i 1))
+               (recurse (+ i 1))))))
+
 (check (first   '(a b c d e f g h i j)) => 'a)
 (check (second  '(a b c d e f g h i j)) => 'b)
 (check (third   '(a b c d e f g h i j)) => 'c)
@@ -64,6 +124,12 @@
 (check (ninth   '(a b c d e f g h i j)) => 'i)
 (check (tenth   '(a b c d e f g h i j)) => 'j)
 
+(call-with-values (lambda ()
+                    (car+cdr '(a . b)))
+                  (lambda (x y)
+                    (check x => 'a)
+                    (check y => 'b)))
+
 (let ((x '(a b c d e))) (check (take  x 0) => '())          (check x => '(a b c d e)))
 (let ((x '(a b c d e))) (check (take! x 0) => '())          (check x => '(a b c d e)))
 (let ((x '(a b c d e))) (check (take  x 1) => '(a))         (check x => '(a b c d e)))
@@ -151,11 +217,6 @@
 (check (append)  => '())
 (check (append!) => '())
 
-(let ((x '(a b c)))             (check (reverse  x) => '(c b a))             (check x => '(a b c)))
-(let ((x '(a b c)))             (check (reverse! x) => '(c b a))             (check x => '(a)))
-(let ((x '(a (b c) d (e (f))))) (check (reverse  x) => '((e (f)) d (b c) a)) (check x => '(a (b c) d (e (f)))))
-(let ((x '(a (b c) d (e (f))))) (check (reverse! x) => '((e (f)) d (b c) a)) (check x => '(a)))
-
 (let ((x '((1 2 3) (4 5 6) (7 8 9))))   (check (concatenate  x) => '(1 2 3 4 5 6 7 8 9))   (check x => '((1 2 3) (4 5 6) (7 8 9))))
 (let ((x '((1 2 3) (4 5 6) (7 8 9))))   (check (concatenate! x) => '(1 2 3 4 5 6 7 8 9))   (check x => '((1 2 3 4 5 6 7 8 9) (4 5 6 7 8 9) (7 8 9))))
 (let ((x '((1 2 3) (4 5 6) (7 . ...)))) (check (concatenate  x) => '(1 2 3 4 5 6 7 . ...)) (check x => '((1 2 3) (4 5 6) (7 . ...))))
@@ -163,13 +224,204 @@
 (let ((x '((1 2 3) (4 5 6) ...)))       (check (concatenate  x) => '(1 2 3 4 5 6 . ...))   (check x => '((1 2 3) (4 5 6) ...)))
 (let ((x '((1 2 3) (4 5 6) ...)))       (check (concatenate! x) => '(1 2 3 4 5 6 . ...))   (check x => '((1 2 3 4 5 6 . ...) (4 5 6 . ...) ...)))
 
+(let ((x '(a b c)))             (check (reverse  x) => '(c b a))             (check x => '(a b c)))
+(let ((x '(a b c)))             (check (reverse! x) => '(c b a))             (check x => '(a)))
+(let ((x '(a (b c) d (e (f))))) (check (reverse  x) => '((e (f)) d (b c) a)) (check x => '(a (b c) d (e (f)))))
+(let ((x '(a (b c) d (e (f))))) (check (reverse! x) => '((e (f)) d (b c) a)) (check x => '(a)))
+
 (let ((x '(3 2 1)) (y '(4 5 6))) (check (append-reverse  x y) => '(1 2 3 4 5 6)) (check x => '(3 2 1))   (check y => '(4 5 6)))
 (let ((x '(3 2 1)) (y '(4 5 6))) (check (append-reverse! x y) => '(1 2 3 4 5 6)) (check x => '(3 4 5 6)) (check y => '(4 5 6)))
 
+(check (zip '(one two three) '(1 2 3) '(odd even odd even odd even odd even)) => '((one 1 odd) (two 2 even) (three 3 odd)))
+(check (zip '(1 2 3)) => '((1) (2) (3)))
+(check (zip '(3 1 4 1) (circular-list #f #t)) => '((3 #f) (1 #t) (4 #f) (1 #t)))
+
+(call-with-values (lambda () (unzip1 '((1 one ONE a A) (2 two TWO b B) (3 three THREE c C) (4 four FOUR d D) (5 five FIVE e E)))) (lambda xs (check xs => '((1 2 3 4 5)))))
+(call-with-values (lambda () (unzip2 '((1 one ONE a A) (2 two TWO b B) (3 three THREE c C) (4 four FOUR d D) (5 five FIVE e E)))) (lambda xs (check xs => '((1 2 3 4 5) (one two three four five)))))
+(call-with-values (lambda () (unzip3 '((1 one ONE a A) (2 two TWO b B) (3 three THREE c C) (4 four FOUR d D) (5 five FIVE e E)))) (lambda xs (check xs => '((1 2 3 4 5) (one two three four five) (ONE TWO THREE FOUR FIVE)))))
+(call-with-values (lambda () (unzip4 '((1 one ONE a A) (2 two TWO b B) (3 three THREE c C) (4 four FOUR d D) (5 five FIVE e E)))) (lambda xs (check xs => '((1 2 3 4 5) (one two three four five) (ONE TWO THREE FOUR FIVE) (a b c d e)))))
+(call-with-values (lambda () (unzip5 '((1 one ONE a A) (2 two TWO b B) (3 three THREE c C) (4 four FOUR d D) (5 five FIVE e E)))) (lambda xs (check xs => '((1 2 3 4 5) (one two three four five) (ONE TWO THREE FOUR FIVE) (a b c d e) (A B C D E)))))
+
+(check (count even? '(3 1 4 1 5 9 2 5 6)) => 3)
+(check (count < '(1 2 4 8) '(2 4 6 8 10 12 14 16)) => 3)
+(check (count < '(3 1 4 1) (circular-list 1 10)) => 2)
+
+(check (fold + 0 '(1 2 3 4 5 6 7 8 9 10)) => 55)
+(check (fold cons '() '(a b c)) => '(c b a))
+(check (fold cons* '() '(a b c) '(1 2 3 4 5)) => '(c 3 b 2 a 1))
+(check (fold (lambda (x k) (if (symbol? x) (+ k 1) k)) 0 '(1 a 2 b 3 c)) => 3)
+(check (fold (lambda (s k) (max k (string-length s))) 0 '("one" "two" "three")) => 5)
+
+(check (fold-right cons '() '(a b c)) => '(a b c))
+(check (fold-right cons* '() '(a b c) '(1 2 3 4 5)) => '(a 1 b 2 c 3))
+(check (fold-right (lambda (x xs) (if (even? x) (cons x xs) xs)) '() '(1 2 3 4 5)) => '(2 4))
+
+(check (pair-fold (lambda (x xs) (set-cdr! x xs) x) '() '(a b c)) => '(c b a))
+
+(check (pair-fold-right cons '() '(a b c)) => '((a b c) (b c) (c)))
+
+(check (reduce max 42 '(1 2 3 4 5 6 7 8 9 10)) => 10)
+(check (reduce max 42 '(1)) => 1)
+(check (reduce max 42 '()) => 42)
+
+(check (reduce-right append '() '((a b c) (d e f) (g h i))) => '(a b c d e f g h i))
+(check (reduce-right append '(x y z) '((a b c) (d e f) (g h i))) => '(a b c d e f g h i))
+(check (reduce-right append '(x y z) '((a b c))) => '(a b c))
+(check (reduce-right append '(x y z) '()) => '(x y z))
+
+(check (unfold (lambda (x) (< 10 x)) square (lambda (x) (+ x 1)) 1) => '(1 4 9 16 25 36 49 64 81 100))
+(check (unfold null-list? car cdr '(a b c)) => '(a b c))
+(check (unfold not-pair? car cdr '(a b c) values) => '(a b c))
+(check (unfold not-pair? car cdr '(a b c . d) values) => '(a b c . d))
+(check (unfold null-list? car cdr '(a b c) (lambda (x) '(d e f))) => '(a b c d e f))
+
+(check (unfold-right zero? square (lambda (x) (- x 1)) 10) => '(1 4 9 16 25 36 49 64 81 100))
+(check (unfold-right null-list? car cdr '(a b c)) => '(c b a))
+(check (unfold-right null-list? car cdr '(c b a) '(d e f)) => '(a b c d e f))
+
+(check (map cadr '((a b) (d e) (g h))) => '(b e h))
+(check (map! cadr '((a b) (d e) (g h))) => '(b e h))
+(check (map-in-order cadr '((a b) (d e) (g h))) => '(b e h))
+(check (map (lambda (n) (expt n n)) '(1 2 3 4 5)) => '(1 4 27 256 3125))
+(check (map! (lambda (n) (expt n n)) '(1 2 3 4 5)) => '(1 4 27 256 3125))
+(check (map-in-order (lambda (n) (expt n n)) '(1 2 3 4 5)) => '(1 4 27 256 3125))
+(check (map + '(1 2 3) '(4 5 6)) => '(5 7 9))
+(check (map! + '(1 2 3) '(4 5 6)) => '(5 7 9))
+(check (map-in-order + '(1 2 3) '(4 5 6)) => '(5 7 9))
+(check (map + '(3 1 4 1) (circular-list 1 0)) => '(4 1 5 1))
+(check (map! + '(3 1 4 1) (circular-list 1 0)) => '(4 1 5 1))
+(check (map-in-order + '(3 1 4 1) (circular-list 1 0)) => '(4 1 5 1))
+(check (let ((count 0)) (map (lambda (ignored) (set! count (+ count 1)) count) '(a b))) => '(1 2))
+(check (let ((count 0)) (map! (lambda (ignored) (set! count (+ count 1)) count) '(a b))) => '(1 2))
+(check (let ((count 0)) (map-in-order (lambda (ignored) (set! count (+ count 1)) count) '(a b))) => '(1 2))
+
+(check (let ((v (make-vector 5))) (for-each (lambda (i) (vector-set! v i (* i i))) '(0 1 2 3 4)) v)  => #(0 1 4 9 16))
+
+(check (append-map! (lambda (x) (list x (- x))) '(1 3 8)) => '(1 -1 3 -3 8 -8))
+
+(check (filter-map (lambda (x) (and (number? x) (* x x))) '(a 1 b 3 c 7)) => '(1 9 49))
+
+(check (parameterize ((current-output-port (open-output-string "")))
+         (pair-for-each (lambda (pair)
+                          (display pair))
+                        '(a b c))
+         (get-output-string (current-output-port)))
+  => "(a b c)(b c)(c)")
+
+(check (filter even? '(0 7 8 8 43 -4)) => '(0 8 8 -4))
+(check (filter! even? '(0 7 8 8 43 -4)) => '(0 8 8 -4))
+
+(call-with-values (lambda () (partition symbol? '(one 2 3 four five 6))) (lambda (x y) (check x => '(one four five)) (check y => '(2 3 6))))
+(call-with-values (lambda () (partition! symbol? '(one 2 3 four five 6))) (lambda (x y) (check x => '(one four five)) (check y => '(2 3 6))))
+
+(check (remove even? '(0 7 8 8 43 -4)) => '(7 43))
+(check (remove! even? '(0 7 8 8 43 -4)) => '(7 43))
+
+(check (find even? '(3 1 4 1 5 9)) => 4)
+
+(check (find-tail even? '(3 1 37 -8 -5 0 0)) => '(-8 -5 0 0))
+(check (find-tail even? '(3 1 37 -5)) => #f)
+
+(check (take-while  even? '(2 18 3 10 22 9)) => '(2 18))
+(check (take-while! even? '(2 18 3 10 22 9)) => '(2 18))
+(check (drop-while  even? '(2 18 3 10 22 9)) => '(3 10 22 9))
+
+(call-with-values (lambda () (span even? '(2 18 3 10 22 9))) (lambda (x y) (check x => '(2 18)) (check y => '(3 10 22 9))))
+(call-with-values (lambda () (span! even? '(2 18 3 10 22 9))) (lambda (x y) (check x => '(2 18)) (check y => '(3 10 22 9))))
+
+(call-with-values (lambda () (break even? '(3 1 4 1 5 9))) (lambda (x y) (check x => '(3 1)) (check y => '(4 1 5 9))))
+(call-with-values (lambda () (break! even? '(3 1 4 1 5 9))) (lambda (x y) (check x => '(3 1)) (check y => '(4 1 5 9))))
+
+(check (any integer? '(a 3 b 2.7)) => #t)
+(check (any integer? '(a 3.1 b 2.7)) => #f)
+(check (any < '(3 1 4 1 5) '(2 7 1 8 2)) => #t)
+
+(check (every integer? '(1 2 3)) => #t)
+(check (every integer? '(1 2 3.14)) => #f)
+(check (every integer? '(1 2 3) '(4 5 6 7)) => #t)
+(check (every integer? '(1 2 3) '(4 5 6 7.0)) => #t)
+(check (every integer? '(1 2 3) (circular-list 4)) => #t)
+
+(check (list-index even? '(3 1 4 1 5 9)) => 2)
+(check (list-index < '(3 1 4 1 5 9 2 5 6) '(2 7 1 8 2)) => 1)
+(check (list-index = '(3 1 4 1 5 9 2 5 6) '(2 7 1 8 2)) => #f)
+
+(check (memq 'a '(a b c)) => '(a b c))
+(check (memq 'b '(a b c)) => '(b c))
+(check (memq 'a '(b c d)) => #f)
+(check (memq (list 'a) '(b (a) c)) => #f)
+(check (member (list 'a) '(b (a) c)) => '((a) c))
+(check (memq 101 '(100 101 102)) => #f)
+(check (memv 101 '(100 101 102)) => '(101 102))
+
+(check (delete 2 '(1 2 3)) => '(1 3))
+(check (delete! 2 '(1 2 3)) => '(1 3))
+
+(check (delete-duplicates '(a b a c a b c z)) => '(a b c z))
+(check (delete-duplicates! '(a b a c a b c z)) => '(a b c z))
+(check (delete-duplicates '((a . 3) (b . 7) (a . 9) (c . 1)) (lambda (x y) (eq? (car x) (car y)))) => '((a . 3) (b . 7) (c . 1)))
+(check (delete-duplicates! '((a . 3) (b . 7) (a . 9) (c . 1)) (lambda (x y) (eq? (car x) (car y)))) => '((a . 3) (b . 7) (c . 1)))
+
+(check (assq 'a '((a 1) (b 2) (c 3))) => '(a 1))
+(check (assq 'b '((a 1) (b 2) (c 3))) => '(b 2))
+(check (assq 'd '((a 1) (b 2) (c 3))) => #f)
+(check (assq (list 'a) '(((a)) ((b)) ((c)))) => #f)
+(check (assoc (list 'a) '(((a)) ((b)) ((c)))) => '((a)))
+(check (assq 5 '((2 3) (5 7) (11 13))) => #f)
+(check (assv 5 '((2 3) (5 7) (11 13))) => '(5 7))
+
 (check (alist-cons 'a 1 '((b . 2) (c . 3))) => '((a . 1) (b . 2) (c . 3)))
 
 (check (alist-copy '((a . 1) (b . 2) (c . 3))) => '((a . 1) (b . 2) (c . 3)))
 
+(check (alist-delete 'a '((a 1) (b 2) (c 3))) => '((b 2) (c 3)))
+(check (alist-delete! 'a '((a 1) (b 2) (c 3))) => '((b 2) (c 3)))
+(check (alist-delete 'b '((a 1) (b 2) (c 3))) => '((a 1) (c 3)))
+(check (alist-delete! 'b '((a 1) (b 2) (c 3))) => '((a 1) (c 3)))
+(check (alist-delete 'c '((a 1) (b 2) (c 3))) => '((a 1) (b 2)))
+(check (alist-delete! 'c '((a 1) (b 2) (c 3))) => '((a 1) (b 2)))
+
+(check (lset= eq? '(b e a) '(a e b) '(e e b a)) => #t)
+(check (lset= eq? '(a)) => #t)
+(check (lset= eq?) => #t)
+
+(check (lset<= eq? '(a) '(a b a) '(a b c c)) => #t)
+(check (lset<= eq? '(a)) => #t)
+(check (lset<= eq?) => #t)
+
+(check (lset-adjoin eq? '(a b c d c e) 'a 'e 'i 'o 'u) => '(u o i a b c d c e))
+
+(check (lset-union eq? '(a b c d e) '(a e i o u)) => '(u o i a b c d e))
+(check (lset-union! eq? '(a b c d e) '(a e i o u)) => '(u o i a b c d e))
+(check (lset-union eq? '(a a c) '(x a x)) => '(x a a c))
+(check (lset-union! eq? '(a a c) '(x a x)) => '(x a a c))
+(check (lset-union eq?) => '())
+(check (lset-union! eq?) => '())
+(check (lset-union eq? '(a b c)) => '(a b c))
+(check (lset-union! eq? '(a b c)) => '(a b c))
+
+(check (lset-intersection eq? '(a b c d e) '(a e i o u)) => '(a e))
+(check (lset-intersection! eq? '(a b c d e) '(a e i o u)) => '(a e))
+(check (lset-intersection eq? '(a x y a) '(x a x z)) => '(a x a))
+(check (lset-intersection! eq? '(a x y a) '(x a x z)) => '(a x a))
+(check (lset-intersection eq? '(a b c)) => '(a b c))
+(check (lset-intersection! eq? '(a b c)) => '(a b c))
+
+(check (lset-difference eq? '(a b c d e) '(a e i o u)) => '(b c d))
+(check (lset-difference! eq? '(a b c d e) '(a e i o u)) => '(b c d))
+(check (lset-difference eq? '(a b c)) => '(a b c))
+(check (lset-difference! eq? '(a b c)) => '(a b c))
+
+(check (lset-xor eq? '(a b c d e) '(a e i o u)) => '(u o i b c d))
+(check (lset-xor! eq? '(a b c d e) '(a e i o u)) => '(u o i b c d))
+(check (lset-xor eq?) => '())
+(check (lset-xor! eq?) => '())
+(check (lset-xor eq? '(a b c d e)) => '(a b c d e))
+(check (lset-xor! eq? '(a b c d e)) => '(a b c d e))
+
+(call-with-values (lambda () (lset-diff+intersection eq? '(a b c d e) '(a e i o u))) (lambda (x y) (check x => '(b c d)) (check y => '(a e))))
+(call-with-values (lambda () (lset-diff+intersection! eq? '(a b c d e) '(a e i o u))) (lambda (x y) (check x => '(b c d)) (check y => '(a e))))
+
 (check-report)
 
-(exit (check-passed? 193))
+(exit (check-passed? 408))

From 5699ce064e51bc6fc7330a46ce26d4162946ca19 Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Sun, 22 Oct 2023 01:56:18 +0900
Subject: [PATCH 26/31] Update `environment` to allow import of the same
 identifier if are same identity

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md                  |  6 +++---
 VERSION                    |  2 +-
 basis/srfi-1.ss            | 18 ++++++++----------
 src/kernel/environment.cpp | 13 ++++++-------
 test/srfi-1.ss             |  7 +------
 5 files changed, 19 insertions(+), 27 deletions(-)

diff --git a/README.md b/README.md
index ae923f820..0da68346b 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.57_amd64.deb
+sudo apt install build/meevax_0.5.58_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.57.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.58.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.57_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.58_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index 7da0228ab..b267c2d62 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.57
+0.5.58
diff --git a/basis/srfi-1.ss b/basis/srfi-1.ss
index d013e8222..c7e791bf9 100644
--- a/basis/srfi-1.ss
+++ b/basis/srfi-1.ss
@@ -23,7 +23,7 @@
             not-pair? pair? set-car! set-cdr! xcons)
           (only (scheme r5rs)
             cond and or let let* eqv? eq? equal? = < zero? + - member assoc
-            apply map values call-with-values)
+            apply map for-each values)
           (only (srfi 8) receive)
           (only (srfi 23) error))
 
@@ -131,16 +131,14 @@
            (values (car pair)
                    (cdr pair)))
 
-         (define (split-at x k)
+         (define (split-at xs k)
            (if (zero? k)
-               (values '() x)
-               (call-with-values (lambda ()
-                                   (split-at (cdr x)
-                                             (- k 1)))
-                                 (lambda (prefix suffix)
-                                   (values (cons (car x)
-                                                 prefix)
-                                           suffix)))))
+               (values '() xs)
+               (receive (a b) (split-at (cdr xs)
+                                        (- k 1))
+                 (values (cons (car xs)
+                               a)
+                         b))))
 
          (define (split-at! x k)
            (if (zero? k)
diff --git a/src/kernel/environment.cpp b/src/kernel/environment.cpp
index 83c4f00d4..b33dcf7d4 100644
--- a/src/kernel/environment.cpp
+++ b/src/kernel/environment.cpp
@@ -218,18 +218,17 @@ inline namespace kernel
 
   auto environment::import(object const& import_set) -> void
   {
-    for (let const& identity : resolve(import_set))
+    for (let const& immigrant : resolve(import_set))
     {
-      assert(identity.is<absolute>());
+      assert(immigrant.is<absolute>());
 
-      if (not is_truthy(std::as_const(*this).identify(car(identity), unit, unit)) or interactive)
+      if (let const& inhabitant = std::as_const(*this).identify(car(immigrant), unit, unit); inhabitant == f or interactive)
       {
-        define(car(identity),
-               cdr(identity));
+        second = cons(immigrant, second);
       }
-      else
+      else if (immigrant != inhabitant)
       {
-        throw error(make<string>("in a program or library declaration, it is an error to import the same identifier more than once with different bindings"), identity);
+        throw error(make<string>("in a program or library declaration, it is an error to import the same identifier more than once with different bindings"), immigrant);
       }
     }
   }
diff --git a/test/srfi-1.ss b/test/srfi-1.ss
index 4d1a3290b..5fe09ed9f 100644
--- a/test/srfi-1.ss
+++ b/test/srfi-1.ss
@@ -2,12 +2,7 @@
         (scheme cxr)
         (scheme process-context)
         (scheme write)
-        (except (srfi 1)
-          cons list make-list list-copy pair? null? car cdr caar cadr cdar cddr
-          caaar caadr cadar caddr cdaar cdadr cddar cdddr caaaar caaadr caadar
-          caaddr cadaar cadadr caddar cadddr cdaaar cdaadr cdadar cdaddr cddaar
-          cddadr cdddar cddddr list-ref length append reverse map for-each memq
-          memv member assq assv assoc set-car! set-cdr!)
+        (srfi 1)
         (srfi 78))
 
 (check (cons 'a 'b) => '(a . b))

From 737fbf168018c1e8b2c5622bff3268401a5af25c Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Sun, 22 Oct 2023 02:12:40 +0900
Subject: [PATCH 27/31] Support R7RS-large library `(scheme list)`

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md           | 56 ++++++++++++++++++++++-----------------------
 VERSION             |  2 +-
 basis/r7rs.ss       | 23 +++++++++++++++++++
 configure/README.md | 50 ++++++++++++++++++++--------------------
 src/main.cpp        |  2 ++
 5 files changed, 79 insertions(+), 54 deletions(-)

diff --git a/README.md b/README.md
index 0da68346b..03b8cfa01 100644
--- a/README.md
+++ b/README.md
@@ -46,34 +46,34 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 |:--------:|--------------|
 | R4RS     | [`(scheme r4rs)`](./basis/r4rs.ss)
 | R5RS     | [`(scheme r5rs)`](./basis/r5rs.ss)
-| R7RS     | [`(scheme base)`](./basis/r7rs.ss) [`(scheme box)`](./basis/r7rs.ss) [`(scheme case-lambda)`](./basis/r7rs.ss) [`(scheme char)`](./basis/r7rs.ss) [`(scheme complex)`](./basis/r7rs.ss) [`(scheme cxr)`](./basis/r7rs.ss) [`(scheme eval)`](./basis/r7rs.ss) [`(scheme file)`](./basis/r7rs.ss) [`(scheme inexact)`](./basis/r7rs.ss) [`(scheme lazy)`](./basis/r7rs.ss) [`(scheme load)`](./basis/r7rs.ss) [`(scheme process-context)`](./basis/r7rs.ss) [`(scheme read)`](./basis/r7rs.ss) [`(scheme repl)`](./basis/r7rs.ss) [`(scheme time)`](./basis/r7rs.ss) [`(scheme write)`](./basis/r7rs.ss)
+| R7RS     | [`(scheme base)`](./basis/r7rs.ss) [`(scheme box)`](./basis/r7rs.ss) [`(scheme case-lambda)`](./basis/r7rs.ss) [`(scheme char)`](./basis/r7rs.ss) [`(scheme complex)`](./basis/r7rs.ss) [`(scheme cxr)`](./basis/r7rs.ss) [`(scheme eval)`](./basis/r7rs.ss) [`(scheme file)`](./basis/r7rs.ss) [`(scheme inexact)`](./basis/r7rs.ss) [`(scheme lazy)`](./basis/r7rs.ss) [`(scheme list)`](./basis/r7rs.ss) [`(scheme load)`](./basis/r7rs.ss) [`(scheme process-context)`](./basis/r7rs.ss) [`(scheme read)`](./basis/r7rs.ss) [`(scheme repl)`](./basis/r7rs.ss) [`(scheme time)`](./basis/r7rs.ss) [`(scheme write)`](./basis/r7rs.ss)
 
 ### SRFIs
 
-| Number                                                  | Title                                                  | Library name                        | Note                              |
-|--------------------------------------------------------:|--------------------------------------------------------|-------------------------------------|-----------------------------------|
-| [  0](https://srfi.schemers.org/srfi-0/srfi-0.html)     | Feature-based conditional expansion construct          | [`(srfi 0)`](./basis/srfi-0.ss)     | R7RS 4.2.1                        |
-| [  1](https://srfi.schemers.org/srfi-1/srfi-1.html)     | List Library                                           | [`(srfi 1)`](./basis/srfi-1.ss)     |                                   |
-| [  4](https://srfi.schemers.org/srfi-4/srfi-4.html)     | Homogeneous numeric vector datatypes                   | [`(srfi 4)`](./basis/srfi-4.ss)     | R7RS 6.9                          |
-| [  6](https://srfi.schemers.org/srfi-6/srfi-6.html)     | Basic String Ports                                     | [`(srfi 6)`](./basis/srfi-6.ss)     | R7RS 6.13                         |
-| [  8](https://srfi.schemers.org/srfi-8/srfi-8.html)     | receive: Binding to multiple values                    | [`(srfi 8)`](./basis/srfi-8.ss)     |                                   |
-| [  9](https://srfi.schemers.org/srfi-9/srfi-9.html)     | Defining Record Types                                  | [`(srfi 9)`](./basis/srfi-9.ss)     | R7RS 5.5                          |
-| [ 10](https://srfi.schemers.org/srfi-10/srfi-10.html)   | #, external form                                       |                                     |                                   |
-| [ 11](https://srfi.schemers.org/srfi-11/srfi-11.html)   | Syntax for receiving multiple values                   | [`(srfi 11)`](./basis/srfi-11.ss)   | R7RS 4.2.2                        |
-| [ 16](https://srfi.schemers.org/srfi-16/srfi-16.html)   | Syntax for procedures of variable arity                | [`(srfi 16)`](./basis/srfi-16.ss)   | R7RS 4.2.9                        |
-| [ 23](https://srfi.schemers.org/srfi-23/srfi-23.html)   | Error reporting mechanism                              | [`(srfi 23)`](./basis/srfi-23.ss)   | R7RS 6.11                         |
-| [ 30](https://srfi.schemers.org/srfi-30/srfi-30.html)   | Nested Multi-line Comments                             |                                     | R7RS 2.2                          |
-| [ 31](https://srfi.schemers.org/srfi-31/srfi-31.html)   | A special form rec for recursive evaluation            | [`(srfi 31)`](./basis/srfi-31.ss)   |                                   |
-| [ 34](https://srfi.schemers.org/srfi-34/srfi-34.html)   | Exception Handling for Programs                        | [`(srfi 34)`](./basis/srfi-34.ss)   | R7RS 6.11                         |
-| [ 38](https://srfi.schemers.org/srfi-38/srfi-38.html)   | External Representation for Data With Shared Structure | [`(srfi 38)`](./basis/srfi-38.ss)   | R7RS 6.13.3                       |
-| [ 39](https://srfi.schemers.org/srfi-39/srfi-39.html)   | Parameter objects                                      | [`(srfi 39)`](./basis/srfi-39.ss)   | R7RS 4.2.6                        |
-| [ 45](https://srfi.schemers.org/srfi-45/srfi-45.html)   | Primitives for Expressing Iterative Lazy Algorithms    | [`(srfi 45)`](./basis/srfi-45.ss)   | R7RS 4.2.5                        |
-| [ 62](https://srfi.schemers.org/srfi-62/srfi-62.html)   | S-expression comments                                  |                                     | R7RS 2.2                          |
-| [ 78](https://srfi.schemers.org/srfi-78/srfi-78.html)   | Lightweight testing                                    | [`(srfi 78)`](./basis/srfi-78.ss)   | Except `check-ec`                 |
-| [ 87](https://srfi.schemers.org/srfi-87/srfi-87.html)   | => in case clauses                                     |                                     | R7RS 4.2.1                        |
-| [ 98](https://srfi.schemers.org/srfi-98/srfi-98.html)   | An interface to access environment variables           | [`(srfi 98)`](./basis/srfi-98.ss)   | R7RS 6.14                         |
-| [111](https://srfi.schemers.org/srfi-111/srfi-111.html) | Boxes                                                  | [`(srfi 111)`](./basis/srfi-111.ss) | [`(scheme box)`](./basis/r7rs.ss) |
-| [149](https://srfi.schemers.org/srfi-149/srfi-149.html) | Basic syntax-rules template extensions                 | [`(srfi 149)`](./basis/srfi-149.ss) | R7RS 4.3.2                        |
+| Number                                                  | Title                                                  | Library name                        | Note                               |
+|--------------------------------------------------------:|--------------------------------------------------------|-------------------------------------|------------------------------------|
+| [  0](https://srfi.schemers.org/srfi-0/srfi-0.html)     | Feature-based conditional expansion construct          | [`(srfi 0)`](./basis/srfi-0.ss)     | R7RS 4.2.1                         |
+| [  1](https://srfi.schemers.org/srfi-1/srfi-1.html)     | List Library                                           | [`(srfi 1)`](./basis/srfi-1.ss)     | [`(scheme list)`](./basis/r7rs.ss) |
+| [  4](https://srfi.schemers.org/srfi-4/srfi-4.html)     | Homogeneous numeric vector datatypes                   | [`(srfi 4)`](./basis/srfi-4.ss)     | R7RS 6.9                           |
+| [  6](https://srfi.schemers.org/srfi-6/srfi-6.html)     | Basic String Ports                                     | [`(srfi 6)`](./basis/srfi-6.ss)     | R7RS 6.13                          |
+| [  8](https://srfi.schemers.org/srfi-8/srfi-8.html)     | receive: Binding to multiple values                    | [`(srfi 8)`](./basis/srfi-8.ss)     |                                    |
+| [  9](https://srfi.schemers.org/srfi-9/srfi-9.html)     | Defining Record Types                                  | [`(srfi 9)`](./basis/srfi-9.ss)     | R7RS 5.5                           |
+| [ 10](https://srfi.schemers.org/srfi-10/srfi-10.html)   | #, external form                                       |                                     |                                    |
+| [ 11](https://srfi.schemers.org/srfi-11/srfi-11.html)   | Syntax for receiving multiple values                   | [`(srfi 11)`](./basis/srfi-11.ss)   | R7RS 4.2.2                         |
+| [ 16](https://srfi.schemers.org/srfi-16/srfi-16.html)   | Syntax for procedures of variable arity                | [`(srfi 16)`](./basis/srfi-16.ss)   | R7RS 4.2.9                         |
+| [ 23](https://srfi.schemers.org/srfi-23/srfi-23.html)   | Error reporting mechanism                              | [`(srfi 23)`](./basis/srfi-23.ss)   | R7RS 6.11                          |
+| [ 30](https://srfi.schemers.org/srfi-30/srfi-30.html)   | Nested Multi-line Comments                             |                                     | R7RS 2.2                           |
+| [ 31](https://srfi.schemers.org/srfi-31/srfi-31.html)   | A special form rec for recursive evaluation            | [`(srfi 31)`](./basis/srfi-31.ss)   |                                    |
+| [ 34](https://srfi.schemers.org/srfi-34/srfi-34.html)   | Exception Handling for Programs                        | [`(srfi 34)`](./basis/srfi-34.ss)   | R7RS 6.11                          |
+| [ 38](https://srfi.schemers.org/srfi-38/srfi-38.html)   | External Representation for Data With Shared Structure | [`(srfi 38)`](./basis/srfi-38.ss)   | R7RS 6.13.3                        |
+| [ 39](https://srfi.schemers.org/srfi-39/srfi-39.html)   | Parameter objects                                      | [`(srfi 39)`](./basis/srfi-39.ss)   | R7RS 4.2.6                         |
+| [ 45](https://srfi.schemers.org/srfi-45/srfi-45.html)   | Primitives for Expressing Iterative Lazy Algorithms    | [`(srfi 45)`](./basis/srfi-45.ss)   | R7RS 4.2.5                         |
+| [ 62](https://srfi.schemers.org/srfi-62/srfi-62.html)   | S-expression comments                                  |                                     | R7RS 2.2                           |
+| [ 78](https://srfi.schemers.org/srfi-78/srfi-78.html)   | Lightweight testing                                    | [`(srfi 78)`](./basis/srfi-78.ss)   | Except `check-ec`                  |
+| [ 87](https://srfi.schemers.org/srfi-87/srfi-87.html)   | => in case clauses                                     |                                     | R7RS 4.2.1                         |
+| [ 98](https://srfi.schemers.org/srfi-98/srfi-98.html)   | An interface to access environment variables           | [`(srfi 98)`](./basis/srfi-98.ss)   | R7RS 6.14                          |
+| [111](https://srfi.schemers.org/srfi-111/srfi-111.html) | Boxes                                                  | [`(srfi 111)`](./basis/srfi-111.ss) | [`(scheme box)`](./basis/r7rs.ss)  |
+| [149](https://srfi.schemers.org/srfi-149/srfi-149.html) | Basic syntax-rules template extensions                 | [`(srfi 149)`](./basis/srfi-149.ss) | R7RS 4.3.2                         |
 
 ## Installation
 
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.58_amd64.deb
+sudo apt install build/meevax_0.5.59_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.58.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.59.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.58_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.59_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index b267c2d62..9904b4381 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.58
+0.5.59
diff --git a/basis/r7rs.ss b/basis/r7rs.ss
index c9fd20029..22353c49b 100644
--- a/basis/r7rs.ss
+++ b/basis/r7rs.ss
@@ -465,6 +465,29 @@
   (import (srfi 45))
   (export delay (rename lazy delay-force) force promise? (rename eager make-promise)))
 
+(define-library (scheme list)
+  (import (srfi 1))
+  (export cons list xcons cons* make-list list-tabulate list-copy circular-list
+          iota pair? null? proper-list? circular-list? dotted-list? not-pair?
+          null-list? list= car cdr caar cadr cdar cddr caaar caadr cadar caddr
+          cdaar cdadr cddar cdddr caaaar caaadr caadar caaddr cadaar cadadr
+          caddar cadddr cdaaar cdaadr cdadar cdaddr cddaar cddadr cdddar cddddr
+          list-ref first second third fourth fifth sixth seventh eighth ninth
+          tenth car+cdr take take! take-right drop drop-right drop-right!
+          split-at split-at! last last-pair length length+ append append!
+          concatenate concatenate! reverse reverse! append-reverse
+          append-reverse! zip unzip1 unzip2 unzip3 unzip4 unzip5 count map map!
+          filter-map map-in-order fold fold-right unfold unfold-right pair-fold
+          pair-fold-right reduce reduce-right append-map append-map! for-each
+          pair-for-each filter filter! partition partition! remove remove! memq
+          memv member find find-tail any every list-index take-while
+          take-while! drop-while span span! break break! delete delete!
+          delete-duplicates delete-duplicates! assq assv assoc alist-cons
+          alist-copy alist-delete alist-delete! lset<= lset= lset-adjoin
+          lset-union lset-union! lset-intersection lset-intersection!
+          lset-difference lset-difference! lset-xor lset-xor!
+          lset-diff+intersection lset-diff+intersection! set-car! set-cdr!))
+
 (define-library (scheme load)
   (import (only (scheme r5rs) load))
   (export load))
diff --git a/configure/README.md b/configure/README.md
index 245acfa70..fae35493a 100644
--- a/configure/README.md
+++ b/configure/README.md
@@ -46,34 +46,34 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 |:--------:|--------------|
 | R4RS     | [`(scheme r4rs)`](./basis/r4rs.ss)
 | R5RS     | [`(scheme r5rs)`](./basis/r5rs.ss)
-| R7RS     | [`(scheme base)`](./basis/r7rs.ss) [`(scheme box)`](./basis/r7rs.ss) [`(scheme case-lambda)`](./basis/r7rs.ss) [`(scheme char)`](./basis/r7rs.ss) [`(scheme complex)`](./basis/r7rs.ss) [`(scheme cxr)`](./basis/r7rs.ss) [`(scheme eval)`](./basis/r7rs.ss) [`(scheme file)`](./basis/r7rs.ss) [`(scheme inexact)`](./basis/r7rs.ss) [`(scheme lazy)`](./basis/r7rs.ss) [`(scheme load)`](./basis/r7rs.ss) [`(scheme process-context)`](./basis/r7rs.ss) [`(scheme read)`](./basis/r7rs.ss) [`(scheme repl)`](./basis/r7rs.ss) [`(scheme time)`](./basis/r7rs.ss) [`(scheme write)`](./basis/r7rs.ss)
+| R7RS     | [`(scheme base)`](./basis/r7rs.ss) [`(scheme box)`](./basis/r7rs.ss) [`(scheme case-lambda)`](./basis/r7rs.ss) [`(scheme char)`](./basis/r7rs.ss) [`(scheme complex)`](./basis/r7rs.ss) [`(scheme cxr)`](./basis/r7rs.ss) [`(scheme eval)`](./basis/r7rs.ss) [`(scheme file)`](./basis/r7rs.ss) [`(scheme inexact)`](./basis/r7rs.ss) [`(scheme lazy)`](./basis/r7rs.ss) [`(scheme list)`](./basis/r7rs.ss) [`(scheme load)`](./basis/r7rs.ss) [`(scheme process-context)`](./basis/r7rs.ss) [`(scheme read)`](./basis/r7rs.ss) [`(scheme repl)`](./basis/r7rs.ss) [`(scheme time)`](./basis/r7rs.ss) [`(scheme write)`](./basis/r7rs.ss)
 
 ### SRFIs
 
-| Number                                                  | Title                                                  | Library name                        | Note                              |
-|--------------------------------------------------------:|--------------------------------------------------------|-------------------------------------|-----------------------------------|
-| [  0](https://srfi.schemers.org/srfi-0/srfi-0.html)     | Feature-based conditional expansion construct          | [`(srfi 0)`](./basis/srfi-0.ss)     | R7RS 4.2.1                        |
-| [  1](https://srfi.schemers.org/srfi-1/srfi-1.html)     | List Library                                           | [`(srfi 1)`](./basis/srfi-1.ss)     |                                   |
-| [  4](https://srfi.schemers.org/srfi-4/srfi-4.html)     | Homogeneous numeric vector datatypes                   | [`(srfi 4)`](./basis/srfi-4.ss)     | R7RS 6.9                          |
-| [  6](https://srfi.schemers.org/srfi-6/srfi-6.html)     | Basic String Ports                                     | [`(srfi 6)`](./basis/srfi-6.ss)     | R7RS 6.13                         |
-| [  8](https://srfi.schemers.org/srfi-8/srfi-8.html)     | receive: Binding to multiple values                    | [`(srfi 8)`](./basis/srfi-8.ss)     |                                   |
-| [  9](https://srfi.schemers.org/srfi-9/srfi-9.html)     | Defining Record Types                                  | [`(srfi 9)`](./basis/srfi-9.ss)     | R7RS 5.5                          |
-| [ 10](https://srfi.schemers.org/srfi-10/srfi-10.html)   | #, external form                                       |                                     |                                   |
-| [ 11](https://srfi.schemers.org/srfi-11/srfi-11.html)   | Syntax for receiving multiple values                   | [`(srfi 11)`](./basis/srfi-11.ss)   | R7RS 4.2.2                        |
-| [ 16](https://srfi.schemers.org/srfi-16/srfi-16.html)   | Syntax for procedures of variable arity                | [`(srfi 16)`](./basis/srfi-16.ss)   | R7RS 4.2.9                        |
-| [ 23](https://srfi.schemers.org/srfi-23/srfi-23.html)   | Error reporting mechanism                              | [`(srfi 23)`](./basis/srfi-23.ss)   | R7RS 6.11                         |
-| [ 30](https://srfi.schemers.org/srfi-30/srfi-30.html)   | Nested Multi-line Comments                             |                                     | R7RS 2.2                          |
-| [ 31](https://srfi.schemers.org/srfi-31/srfi-31.html)   | A special form rec for recursive evaluation            | [`(srfi 31)`](./basis/srfi-31.ss)   |                                   |
-| [ 34](https://srfi.schemers.org/srfi-34/srfi-34.html)   | Exception Handling for Programs                        | [`(srfi 34)`](./basis/srfi-34.ss)   | R7RS 6.11                         |
-| [ 38](https://srfi.schemers.org/srfi-38/srfi-38.html)   | External Representation for Data With Shared Structure | [`(srfi 38)`](./basis/srfi-38.ss)   | R7RS 6.13.3                       |
-| [ 39](https://srfi.schemers.org/srfi-39/srfi-39.html)   | Parameter objects                                      | [`(srfi 39)`](./basis/srfi-39.ss)   | R7RS 4.2.6                        |
-| [ 45](https://srfi.schemers.org/srfi-45/srfi-45.html)   | Primitives for Expressing Iterative Lazy Algorithms    | [`(srfi 45)`](./basis/srfi-45.ss)   | R7RS 4.2.5                        |
-| [ 62](https://srfi.schemers.org/srfi-62/srfi-62.html)   | S-expression comments                                  |                                     | R7RS 2.2                          |
-| [ 78](https://srfi.schemers.org/srfi-78/srfi-78.html)   | Lightweight testing                                    | [`(srfi 78)`](./basis/srfi-78.ss)   | Except `check-ec`                 |
-| [ 87](https://srfi.schemers.org/srfi-87/srfi-87.html)   | => in case clauses                                     |                                     | R7RS 4.2.1                        |
-| [ 98](https://srfi.schemers.org/srfi-98/srfi-98.html)   | An interface to access environment variables           | [`(srfi 98)`](./basis/srfi-98.ss)   | R7RS 6.14                         |
-| [111](https://srfi.schemers.org/srfi-111/srfi-111.html) | Boxes                                                  | [`(srfi 111)`](./basis/srfi-111.ss) | [`(scheme box)`](./basis/r7rs.ss) |
-| [149](https://srfi.schemers.org/srfi-149/srfi-149.html) | Basic syntax-rules template extensions                 | [`(srfi 149)`](./basis/srfi-149.ss) | R7RS 4.3.2                        |
+| Number                                                  | Title                                                  | Library name                        | Note                               |
+|--------------------------------------------------------:|--------------------------------------------------------|-------------------------------------|------------------------------------|
+| [  0](https://srfi.schemers.org/srfi-0/srfi-0.html)     | Feature-based conditional expansion construct          | [`(srfi 0)`](./basis/srfi-0.ss)     | R7RS 4.2.1                         |
+| [  1](https://srfi.schemers.org/srfi-1/srfi-1.html)     | List Library                                           | [`(srfi 1)`](./basis/srfi-1.ss)     | [`(scheme list)`](./basis/r7rs.ss) |
+| [  4](https://srfi.schemers.org/srfi-4/srfi-4.html)     | Homogeneous numeric vector datatypes                   | [`(srfi 4)`](./basis/srfi-4.ss)     | R7RS 6.9                           |
+| [  6](https://srfi.schemers.org/srfi-6/srfi-6.html)     | Basic String Ports                                     | [`(srfi 6)`](./basis/srfi-6.ss)     | R7RS 6.13                          |
+| [  8](https://srfi.schemers.org/srfi-8/srfi-8.html)     | receive: Binding to multiple values                    | [`(srfi 8)`](./basis/srfi-8.ss)     |                                    |
+| [  9](https://srfi.schemers.org/srfi-9/srfi-9.html)     | Defining Record Types                                  | [`(srfi 9)`](./basis/srfi-9.ss)     | R7RS 5.5                           |
+| [ 10](https://srfi.schemers.org/srfi-10/srfi-10.html)   | #, external form                                       |                                     |                                    |
+| [ 11](https://srfi.schemers.org/srfi-11/srfi-11.html)   | Syntax for receiving multiple values                   | [`(srfi 11)`](./basis/srfi-11.ss)   | R7RS 4.2.2                         |
+| [ 16](https://srfi.schemers.org/srfi-16/srfi-16.html)   | Syntax for procedures of variable arity                | [`(srfi 16)`](./basis/srfi-16.ss)   | R7RS 4.2.9                         |
+| [ 23](https://srfi.schemers.org/srfi-23/srfi-23.html)   | Error reporting mechanism                              | [`(srfi 23)`](./basis/srfi-23.ss)   | R7RS 6.11                          |
+| [ 30](https://srfi.schemers.org/srfi-30/srfi-30.html)   | Nested Multi-line Comments                             |                                     | R7RS 2.2                           |
+| [ 31](https://srfi.schemers.org/srfi-31/srfi-31.html)   | A special form rec for recursive evaluation            | [`(srfi 31)`](./basis/srfi-31.ss)   |                                    |
+| [ 34](https://srfi.schemers.org/srfi-34/srfi-34.html)   | Exception Handling for Programs                        | [`(srfi 34)`](./basis/srfi-34.ss)   | R7RS 6.11                          |
+| [ 38](https://srfi.schemers.org/srfi-38/srfi-38.html)   | External Representation for Data With Shared Structure | [`(srfi 38)`](./basis/srfi-38.ss)   | R7RS 6.13.3                        |
+| [ 39](https://srfi.schemers.org/srfi-39/srfi-39.html)   | Parameter objects                                      | [`(srfi 39)`](./basis/srfi-39.ss)   | R7RS 4.2.6                         |
+| [ 45](https://srfi.schemers.org/srfi-45/srfi-45.html)   | Primitives for Expressing Iterative Lazy Algorithms    | [`(srfi 45)`](./basis/srfi-45.ss)   | R7RS 4.2.5                         |
+| [ 62](https://srfi.schemers.org/srfi-62/srfi-62.html)   | S-expression comments                                  |                                     | R7RS 2.2                           |
+| [ 78](https://srfi.schemers.org/srfi-78/srfi-78.html)   | Lightweight testing                                    | [`(srfi 78)`](./basis/srfi-78.ss)   | Except `check-ec`                  |
+| [ 87](https://srfi.schemers.org/srfi-87/srfi-87.html)   | => in case clauses                                     |                                     | R7RS 4.2.1                         |
+| [ 98](https://srfi.schemers.org/srfi-98/srfi-98.html)   | An interface to access environment variables           | [`(srfi 98)`](./basis/srfi-98.ss)   | R7RS 6.14                          |
+| [111](https://srfi.schemers.org/srfi-111/srfi-111.html) | Boxes                                                  | [`(srfi 111)`](./basis/srfi-111.ss) | [`(scheme box)`](./basis/r7rs.ss)  |
+| [149](https://srfi.schemers.org/srfi-149/srfi-149.html) | Basic syntax-rules template extensions                 | [`(srfi 149)`](./basis/srfi-149.ss) | R7RS 4.3.2                         |
 
 ## Installation
 
diff --git a/src/main.cpp b/src/main.cpp
index b4e9aaab3..33a6a6424 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -29,6 +29,7 @@ auto main(int const argc, char const* const* const argv) -> int
     if (e.configure(argc, argv); e.interactive)
     {
       e.import("(scheme base)"_r);
+      e.import("(scheme box)"_r);
       e.import("(scheme case-lambda)"_r);
       e.import("(scheme char)"_r);
       e.import("(scheme complex)"_r);
@@ -37,6 +38,7 @@ auto main(int const argc, char const* const* const argv) -> int
       e.import("(scheme file)"_r);
       e.import("(scheme inexact)"_r);
       e.import("(scheme lazy)"_r);
+      e.import("(scheme list)"_r);
       e.import("(scheme load)"_r);
       e.import("(scheme process-context)"_r);
       e.import("(scheme read)"_r);

From 8742f5090629be6675521a449c829ffdf2d59d9d Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Sun, 22 Oct 2023 19:39:11 +0900
Subject: [PATCH 28/31] Remove CMake target `format`

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 CMakeLists.txt        | 115 +++++++++++++++++++++---------------------
 README.md             |   6 +--
 VERSION               |   2 +-
 basis/]               |   0
 configure/basis.cmake |   4 +-
 configure/basis.hpp   |  44 ++++++++--------
 6 files changed, 84 insertions(+), 87 deletions(-)
 delete mode 100644 basis/]

diff --git a/CMakeLists.txt b/CMakeLists.txt
index f59e8223f..a9b46b3c8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5,10 +5,11 @@ execute_process(
   COMMAND tr -d "\n"
   OUTPUT_VARIABLE CURRENT_VERSION)
 
-project(meevax DESCRIPTION "A programmable programming language"
-               HOMEPAGE_URL "https://github.com/yamacir-kit/meevax"
-               LANGUAGES CXX
-               VERSION ${CURRENT_VERSION})
+project(meevax
+  DESCRIPTION "A programmable programming language"
+  HOMEPAGE_URL "https://github.com/yamacir-kit/meevax"
+  LANGUAGES CXX
+  VERSION ${CURRENT_VERSION})
 
 include(GNUInstallDirs)
 
@@ -20,9 +21,9 @@ string(JOIN " " AGGRESSIVE_OPTIMIZATION_OPTIONS
   )
 
 set(CMAKE_CXX_EXTENSIONS OFF)
-set(CMAKE_CXX_FLAGS_DEBUG          "-Og -gdwarf-4") # NOTE: The `-gdwarf-4` option is set due to the following issues with Clang 14 and Valgrind versions below 3.20: https://bugzilla.mozilla.org/show_bug.cgi?id=1758782
-set(CMAKE_CXX_FLAGS_MINSIZEREL     "-Os           -DNDEBUG")
-set(CMAKE_CXX_FLAGS_RELEASE        "-O2           -DNDEBUG ${AGGRESSIVE_OPTIMIZATION_OPTIONS}")
+set(CMAKE_CXX_FLAGS_DEBUG "-Og -gdwarf-4") # NOTE: The `-gdwarf-4` option is set due to the following issues with Clang 14 and Valgrind versions below 3.20: https://bugzilla.mozilla.org/show_bug.cgi?id=1758782
+set(CMAKE_CXX_FLAGS_MINSIZEREL "-Os -DNDEBUG")
+set(CMAKE_CXX_FLAGS_RELEASE "-O2 -DNDEBUG ${AGGRESSIVE_OPTIMIZATION_OPTIONS}")
 set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-O2 -gdwarf-4 -DNDEBUG")
 set(CMAKE_CXX_FLAGS "-Wall -Wextra -Wpedantic -pipe")
 set(CMAKE_CXX_STANDARD 17)
@@ -73,30 +74,23 @@ file(GLOB_RECURSE ${PROJECT_NAME}_KERNEL_SOURCES ${CMAKE_CURRENT_SOURCE_DIR}/src
 
 target_sources(kernel PRIVATE ${${PROJECT_NAME}_KERNEL_SOURCES})
 
-target_include_directories(kernel PUBLIC
-  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
-  $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>)
+target_include_directories(kernel
+  PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+  PUBLIC $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>)
 
-target_link_libraries(kernel PRIVATE ${CMAKE_DL_LIBS}
-                             PUBLIC gmp)
+target_link_libraries(kernel
+  PRIVATE ${CMAKE_DL_LIBS}
+  PUBLIC gmp)
 
-set_target_properties(kernel PROPERTIES OUTPUT_NAME ${PROJECT_NAME} # Rename libkernel => libmeevax
-                                        VERSION     ${PROJECT_VERSION}
-                                        SOVERSION   ${PROJECT_VERSION_MAJOR}
-                                        LINK_FLAGS_RELEASE -s)
-
-# ---- Target format -----------------------------------------------------------
-
-add_executable(format)
-
-target_sources(format PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/src/format.cpp)
-
-target_link_libraries(format PRIVATE kernel)
+set_target_properties(kernel PROPERTIES
+  OUTPUT_NAME ${PROJECT_NAME} # Rename libkernel => libmeevax
+  VERSION     ${PROJECT_VERSION}
+  SOVERSION   ${PROJECT_VERSION_MAJOR}
+  LINK_FLAGS_RELEASE -s)
 
 # ---- Target basis ------------------------------------------------------------
 
 add_custom_target(basis
-  DEPENDS format
   COMMAND ${CMAKE_COMMAND} -P ${CMAKE_CURRENT_SOURCE_DIR}/configure/basis.cmake)
 
 # ---- Target shell ------------------------------------------------------------
@@ -109,8 +103,9 @@ target_sources(shell PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/src/main.cpp)
 
 target_link_libraries(shell PRIVATE kernel)
 
-set_target_properties(shell PROPERTIES OUTPUT_NAME ${PROJECT_NAME} # Rename shell => meevax
-                                       LINK_FLAGS_RELEASE -s)
+set_target_properties(shell PROPERTIES
+  OUTPUT_NAME ${PROJECT_NAME} # Rename shell => meevax
+  LINK_FLAGS_RELEASE -s)
 
 # ---- CMake Package -----------------------------------------------------------
 
@@ -122,29 +117,30 @@ write_basic_package_version_file(
 
 # ---- Target install ----------------------------------------------------------
 
-# /usr/lib/libmeevax
-install(TARGETS kernel
-        EXPORT ${PROJECT_NAME}-config
-        ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
-        LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})
+install( # /usr/lib/libmeevax
+  TARGETS kernel
+  EXPORT ${PROJECT_NAME}-config
+  ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})
 
-# /usr/bin/meevax
-install(TARGETS shell
-        RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+install( # /usr/bin/meevax
+  TARGETS shell
+  RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
 
-# /usr/include/meevax
-install(DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/include/
-        DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+install( # /usr/include/meevax
+  DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/include/
+  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
 
-# /usr/share/meevax/meevax-config.cmake
-install(EXPORT ${PROJECT_NAME}-config
-        EXPORT_LINK_INTERFACE_LIBRARIES
-        DESTINATION ${CMAKE_INSTALL_DATADIR}/${PROJECT_NAME}
-        NAMESPACE Meevax::)
+install( # /usr/share/meevax/meevax-config.cmake
+  EXPORT ${PROJECT_NAME}-config
+  EXPORT_LINK_INTERFACE_LIBRARIES
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/${PROJECT_NAME}
+  NAMESPACE Meevax::)
 
 # /usr/share/meevax/meevax-config-version.cmake
-install(FILES ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}-config-version.cmake
-        DESTINATION ${CMAKE_INSTALL_DATADIR}/${PROJECT_NAME})
+install(
+  FILES ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}-config-version.cmake
+  DESTINATION ${CMAKE_INSTALL_DATADIR}/${PROJECT_NAME})
 
 # ---- Target package ----------------------------------------------------------
 
@@ -164,20 +160,22 @@ enable_testing()
 
 find_program(${PROJECT_NAME}_MEMORY_CHECK_COMMAND valgrind)
 
-set(${PROJECT_NAME}_MEMORY_CHECK_COMMAND_OPTIONS --error-exitcode=1 # = EXIT_FAILURE)
-                                                 --leak-check=full
-                                                 --quiet
-                                                 --show-leak-kinds=all)
+set(${PROJECT_NAME}_MEMORY_CHECK_OPTIONS
+  --error-exitcode=1 # = EXIT_FAILURE)
+  --leak-check=full
+  --quiet
+  --show-leak-kinds=all)
 
 file(GLOB ${PROJECT_NAME}_TEST_SS ${CMAKE_CURRENT_SOURCE_DIR}/test/*.ss)
 
 foreach(EACH IN LISTS ${PROJECT_NAME}_TEST_SS)
   get_filename_component(FILENAME ${EACH} NAME_WE)
-  add_test(NAME ${FILENAME}
-           COMMAND ${${PROJECT_NAME}_MEMORY_CHECK_COMMAND}
-                   ${${PROJECT_NAME}_MEMORY_CHECK_COMMAND_OPTIONS}
-                   ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/meevax
-                   ${EACH})
+  add_test(
+    NAME ${FILENAME}
+    COMMAND ${${PROJECT_NAME}_MEMORY_CHECK_COMMAND}
+            ${${PROJECT_NAME}_MEMORY_CHECK_OPTIONS}
+            ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/meevax
+            ${EACH})
 endforeach()
 
 file(GLOB ${PROJECT_NAME}_TEST_CPP ${CMAKE_CURRENT_SOURCE_DIR}/test/*.cpp)
@@ -187,10 +185,11 @@ foreach(EACH IN LISTS ${PROJECT_NAME}_TEST_CPP)
   add_executable(assert-${FILENAME} ${EACH})
   add_dependencies(assert-${FILENAME} basis)
   target_link_libraries(assert-${FILENAME} PRIVATE kernel)
-  add_test(NAME assert-${FILENAME}
-           COMMAND ${${PROJECT_NAME}_MEMORY_CHECK_COMMAND}
-                   ${${PROJECT_NAME}_MEMORY_CHECK_COMMAND_OPTIONS}
-                   ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/assert-${FILENAME})
+  add_test(
+    NAME assert-${FILENAME}
+    COMMAND ${${PROJECT_NAME}_MEMORY_CHECK_COMMAND}
+            ${${PROJECT_NAME}_MEMORY_CHECK_OPTIONS}
+            ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/assert-${FILENAME})
 endforeach()
 
 # ---- Additional Targets ------------------------------------------------------
diff --git a/README.md b/README.md
index 03b8cfa01..adf253ff1 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.59_amd64.deb
+sudo apt install build/meevax_0.5.60_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.59.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.60.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.59_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.60_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index 9904b4381..dd78e5f59 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.59
+0.5.60
diff --git a/basis/] b/basis/]
deleted file mode 100644
index e69de29bb..000000000
diff --git a/configure/basis.cmake b/configure/basis.cmake
index e22306c1d..32884bc9c 100644
--- a/configure/basis.cmake
+++ b/configure/basis.cmake
@@ -7,9 +7,7 @@ file(GLOB ${PROJECT_NAME}_BASIS_SOURCES ${TOPLEVEL}/basis/*.ss)
 
 foreach(EACH IN LISTS ${PROJECT_NAME}_BASIS_SOURCES)
   get_filename_component(FILENAME ${EACH} NAME)
-  execute_process(
-    COMMAND ${TOPLEVEL}/build/bin/format ${EACH}
-    OUTPUT_VARIABLE CONFIGURED_${FILENAME})
+  file(READ ${EACH} ${FILENAME})
 endforeach()
 
 configure_file(
diff --git a/configure/basis.hpp b/configure/basis.hpp
index 423db2e71..eac3bb9ee 100644
--- a/configure/basis.hpp
+++ b/configure/basis.hpp
@@ -32,28 +32,28 @@ inline namespace kernel
   constexpr auto basis()
   {
     return make_array(
-      R"##(${CONFIGURED_meevax.ss})##",
-      R"##(${CONFIGURED_r4rs.ss})##",
-      R"##(${CONFIGURED_r5rs.ss})##",
-      R"##(${CONFIGURED_r7rs.ss})##",
-      R"##(${CONFIGURED_srfi-0.ss})##",
-      R"##(${CONFIGURED_srfi-1.ss})##",
-      R"##(${CONFIGURED_srfi-4.ss})##",
-      R"##(${CONFIGURED_srfi-6.ss})##",
-      R"##(${CONFIGURED_srfi-8.ss})##",
-      R"##(${CONFIGURED_srfi-9.ss})##",
-      R"##(${CONFIGURED_srfi-11.ss})##",
-      R"##(${CONFIGURED_srfi-16.ss})##",
-      R"##(${CONFIGURED_srfi-23.ss})##",
-      R"##(${CONFIGURED_srfi-31.ss})##",
-      R"##(${CONFIGURED_srfi-34.ss})##",
-      R"##(${CONFIGURED_srfi-38.ss})##",
-      R"##(${CONFIGURED_srfi-39.ss})##",
-      R"##(${CONFIGURED_srfi-45.ss})##",
-      R"##(${CONFIGURED_srfi-78.ss})##",
-      R"##(${CONFIGURED_srfi-98.ss})##",
-      R"##(${CONFIGURED_srfi-111.ss})##",
-      R"##(${CONFIGURED_srfi-149.ss})##");
+      R"##(${meevax.ss})##",
+      R"##(${r4rs.ss})##",
+      R"##(${r5rs.ss})##",
+      R"##(${r7rs.ss})##",
+      R"##(${srfi-0.ss})##",
+      R"##(${srfi-1.ss})##",
+      R"##(${srfi-4.ss})##",
+      R"##(${srfi-6.ss})##",
+      R"##(${srfi-8.ss})##",
+      R"##(${srfi-9.ss})##",
+      R"##(${srfi-11.ss})##",
+      R"##(${srfi-16.ss})##",
+      R"##(${srfi-23.ss})##",
+      R"##(${srfi-31.ss})##",
+      R"##(${srfi-34.ss})##",
+      R"##(${srfi-38.ss})##",
+      R"##(${srfi-39.ss})##",
+      R"##(${srfi-45.ss})##",
+      R"##(${srfi-78.ss})##",
+      R"##(${srfi-98.ss})##",
+      R"##(${srfi-111.ss})##",
+      R"##(${srfi-149.ss})##");
   }
 } // namespace kernel
 } // namespace meevax

From a1244ab76cf38d473b7888adff3c2a4d115d05f5 Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Tue, 24 Oct 2023 22:04:27 +0900
Subject: [PATCH 29/31] Remove free function `is_truthy`

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 CMakeLists.txt                                  |  2 --
 README.md                                       |  6 +++---
 VERSION                                         |  2 +-
 include/meevax/kernel/boolean.hpp               |  3 +--
 include/meevax/kernel/dynamic_environment.hpp   |  2 +-
 include/meevax/kernel/syntactic_environment.hpp | 14 +++++++-------
 src/kernel/boolean.cpp                          |  6 +-----
 src/kernel/boot.cpp                             |  4 ++--
 src/kernel/environment.cpp                      |  6 +++---
 src/kernel/implementation_dependent.cpp         |  2 +-
 10 files changed, 20 insertions(+), 27 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index a9b46b3c8..6008cbafa 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -68,8 +68,6 @@ configure_file(${CMAKE_CURRENT_SOURCE_DIR}/configure/version.cpp ${CMAKE_CURRENT
 
 add_library(kernel SHARED)
 
-add_library(${PROJECT_NAME}::kernel ALIAS kernel)
-
 file(GLOB_RECURSE ${PROJECT_NAME}_KERNEL_SOURCES ${CMAKE_CURRENT_SOURCE_DIR}/src/*/*.cpp)
 
 target_sources(kernel PRIVATE ${${PROJECT_NAME}_KERNEL_SOURCES})
diff --git a/README.md b/README.md
index adf253ff1..0895557dc 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.60_amd64.deb
+sudo apt install build/meevax_0.5.61_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.60.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.61.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.60_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.61_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index dd78e5f59..57bba1228 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.60
+0.5.61
diff --git a/include/meevax/kernel/boolean.hpp b/include/meevax/kernel/boolean.hpp
index f73009d42..8a0065fc6 100644
--- a/include/meevax/kernel/boolean.hpp
+++ b/include/meevax/kernel/boolean.hpp
@@ -24,9 +24,8 @@ namespace meevax
 inline namespace kernel
 {
   let extern const t;
-  let extern const f;
 
-  auto is_truthy(object const&) -> bool;
+  let extern const f;
 } // namespace kernel
 } // namespace meevax
 
diff --git a/include/meevax/kernel/dynamic_environment.hpp b/include/meevax/kernel/dynamic_environment.hpp
index 62a6db453..9f50c4db6 100644
--- a/include/meevax/kernel/dynamic_environment.hpp
+++ b/include/meevax/kernel/dynamic_environment.hpp
@@ -256,7 +256,7 @@ inline namespace kernel
           *  where c' = (if <boolean> c1 c2)
           *
           * ----------------------------------------------------------------- */
-          c = is_truthy(car(s)) ? cadr(c) : caddr(c);
+          c = car(s) != f ? cadr(c) : caddr(c);
           s = cdr(s);
           goto fetch;
 
diff --git a/include/meevax/kernel/syntactic_environment.hpp b/include/meevax/kernel/syntactic_environment.hpp
index f77338d19..61417f644 100644
--- a/include/meevax/kernel/syntactic_environment.hpp
+++ b/include/meevax/kernel/syntactic_environment.hpp
@@ -190,17 +190,17 @@ inline namespace kernel
       *  call to one of their arguments. Exceptions are noted in the individual
       *  descriptions.
       *
-      *  Note: In contrast to other dialects of Lisp, the order of evaluation
+      *  NOTE: In contrast to other dialects of Lisp, the order of evaluation
       *  is unspecified, and the operator expression and the operand
       *  expressions are always evaluated with the same evaluation rules.
       *
-      *  Note: Although the order of evaluation is otherwise unspecified, the
+      *  NOTE: Although the order of evaluation is otherwise unspecified, the
       *  effect of any concurrent evaluation of the operator and operand
       *  expressions is constrained to be consistent with some sequential order
       *  of evaluation. The order of evaluation may be chosen differently for
       *  each procedure call.
       *
-      *  Note: In many dialects of Lisp, the empty list, (), is a legitimate
+      *  NOTE: In many dialects of Lisp, the empty list, (), is a legitimate
       *  expression evaluating to itself. In Scheme, it is an error.
       *
       * ------------------------------------------------------------------ */
@@ -519,7 +519,7 @@ inline namespace kernel
       *  difference between the two is that include-ci reads each file as if it
       *  began with the #!fold-case directive, while include does not.
       *
-      *  Note: Implementations are encouraged to search for files in the
+      *  NOTE: Implementations are encouraged to search for files in the
       *  directory which contains the including file, and to provide a way for
       *  users to specify other directories to search.
       *
@@ -997,7 +997,7 @@ inline namespace kernel
         }
         else if (expression.is<syntactic_closure>())
         {
-          if (let const& identity = std::as_const(*this).identify(expression, bound_variables, free_variables); is_truthy(identity)) // The syntactic-closure is an alias
+          if (let const& identity = std::as_const(*this).identify(expression, bound_variables, free_variables); identity != f) // The syntactic-closure is an alias
           {
             return syntax::reference(*this, expression, bound_variables, free_variables, continuation, tail);
           }
@@ -1115,7 +1115,7 @@ inline namespace kernel
       {
         return f;
       }
-      else if (let const& x = assq(variable, free_variables); is_truthy(x))
+      else if (let const& x = assq(variable, free_variables); x != f)
       {
         return cdr(x).as<injector>()(bound_variables);
       }
@@ -1169,7 +1169,7 @@ inline namespace kernel
       {
         return f;
       }
-      else if (let const& identity = std::as_const(*this).identify(variable, bound_variables, free_variables); is_truthy(identity))
+      else if (let const& identity = std::as_const(*this).identify(variable, bound_variables, free_variables); identity != f)
       {
         return identity;
       }
diff --git a/src/kernel/boolean.cpp b/src/kernel/boolean.cpp
index 210edafa4..b5493203d 100644
--- a/src/kernel/boolean.cpp
+++ b/src/kernel/boolean.cpp
@@ -22,11 +22,7 @@ namespace meevax
 inline namespace kernel
 {
   let const t = make<bool>(true);
-  let const f = make<bool>(false);
 
-  auto is_truthy(object const& x) -> bool
-  {
-    return not eq(x, f);
-  }
+  let const f = make<bool>(false);
 } // namespace kernel
 } // namespace meevax
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index b1b7386b7..0dd39c821 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -48,7 +48,7 @@ inline namespace kernel
 
       library.define<procedure>("not", [](let const& xs)
       {
-        return not is_truthy(xs[0]);
+        return xs[0] == f;
       });
     });
 
@@ -283,7 +283,7 @@ inline namespace kernel
         }
         else if (let const& status = car(xs); status.is<bool>())
         {
-          throw is_truthy(status) ? EXIT_SUCCESS : EXIT_FAILURE;
+          throw status != f ? EXIT_SUCCESS : EXIT_FAILURE;
         }
         else
         {
diff --git a/src/kernel/environment.cpp b/src/kernel/environment.cpp
index b33dcf7d4..725d1df09 100644
--- a/src/kernel/environment.cpp
+++ b/src/kernel/environment.cpp
@@ -119,7 +119,7 @@ inline namespace kernel
           return filter([&](let const& identity)
                         {
                           assert(identity.is<absolute>());
-                          return is_truthy(memq(car(identity), identities));
+                          return memq(car(identity), identities) != f;
                         },
                         resolve(import_set));
         };
@@ -141,7 +141,7 @@ inline namespace kernel
           return filter([&](let const& identity)
                         {
                           assert(identity.is<absolute>());
-                          return not is_truthy(memq(car(identity), identities));
+                          return memq(car(identity), identities) == f;
                         },
                         resolve(import_set));
         };
@@ -189,7 +189,7 @@ inline namespace kernel
                        assert(identity.is<absolute>());
                        assert(car(identity).is_also<identifier>());
 
-                       if (let const& renaming = assq(car(identity), renamings); is_truthy(renaming))
+                       if (let const& renaming = assq(car(identity), renamings); renaming != f)
                        {
                          assert(cadr(renaming).is<symbol>());
                          return make<absolute>(cadr(renaming), cdr(identity));
diff --git a/src/kernel/implementation_dependent.cpp b/src/kernel/implementation_dependent.cpp
index b48ee114b..421e54113 100644
--- a/src/kernel/implementation_dependent.cpp
+++ b/src/kernel/implementation_dependent.cpp
@@ -48,7 +48,7 @@ inline namespace kernel
     }
     else
     {
-      return eq(requirement, make_symbol("else")) or is_truthy(memq(requirement, features()));
+      return requirement == make_symbol("else") or memq(requirement, features()) != f;
     }
   }
 

From d6450dbd38a7c93446c47efd503ed282b8f7a9a1 Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Tue, 24 Oct 2023 22:43:19 +0900
Subject: [PATCH 30/31] Lipsticks

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md                                      |  6 +++---
 VERSION                                        |  2 +-
 ]end(                                          |  0
 include/meevax/kernel/configurator.hpp         |  8 ++++----
 .../kernel/input_homogeneous_vector_port.hpp   |  4 ++--
 include/meevax/memory/collector.hpp            |  2 +-
 include/meevax/utility/hexdump.hpp             |  4 ++--
 src/kernel/boot.cpp                            | 18 +++++++++---------
 src/kernel/environment.cpp                     |  2 +-
 src/kernel/implementation_dependent.cpp        |  8 +++++---
 src/kernel/number.cpp                          |  2 +-
 src/kernel/string.cpp                          |  4 ++--
 src/kernel/symbol.cpp                          |  2 +-
 src/kernel/textual_input_port.cpp              |  4 ++--
 src/kernel/vector.cpp                          |  6 +++---
 test/list.cpp                                  | 10 ++++------
 16 files changed, 41 insertions(+), 41 deletions(-)
 create mode 100644 ]end(

diff --git a/README.md b/README.md
index 0895557dc..5c2e7dc26 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.61_amd64.deb
+sudo apt install build/meevax_0.5.62_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.61.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.62.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.61_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.62_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index 57bba1228..1efaf43fe 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.61
+0.5.62
diff --git a/]end( b/]end(
new file mode 100644
index 000000000..e69de29bb
diff --git a/include/meevax/kernel/configurator.hpp b/include/meevax/kernel/configurator.hpp
index 6cf2a7b09..ccddd4d83 100644
--- a/include/meevax/kernel/configurator.hpp
+++ b/include/meevax/kernel/configurator.hpp
@@ -126,11 +126,11 @@ inline namespace kernel
 
       auto search = [&](auto&& name) -> auto const&
       {
-        if (auto iter = std::find_if(std::begin(options), std::end(options), [&](auto&& option)
+        if (auto iter = std::find_if(options.begin(), options.end(), [&](auto&& option)
                         {
                           return std::regex_match(name, option.pattern);
                         });
-            iter != std::end(options))
+            iter != options.end())
         {
           return *iter;
         }
@@ -142,7 +142,7 @@ inline namespace kernel
 
       std::vector<object> expressions {};
 
-      for (auto iter = std::next(std::begin(args)); iter != std::end(args); ++iter)
+      for (auto iter = std::next(args.begin()); iter != args.end(); ++iter)
       {
         static std::regex const pattern { R"(--(\w[-\w]+)(?:=(.*))?|-([\w]+))" };
 
@@ -150,7 +150,7 @@ inline namespace kernel
         {
           auto read = [&]()
           {
-            if (std::next(iter) != std::cend(args))
+            if (std::next(iter) != args.end())
             {
               return input_string_port(*++iter).read();
             }
diff --git a/include/meevax/kernel/input_homogeneous_vector_port.hpp b/include/meevax/kernel/input_homogeneous_vector_port.hpp
index 00e83c2b8..e448a3eb9 100644
--- a/include/meevax/kernel/input_homogeneous_vector_port.hpp
+++ b/include/meevax/kernel/input_homogeneous_vector_port.hpp
@@ -61,8 +61,8 @@ inline namespace kernel
       }
       else
       {
-        let const v =  make<homogeneous_vector<T>>(std::begin(deque), std::next(std::begin(deque), size));
-        deque.erase(std::begin(deque), std::next(std::begin(deque), size));
+        let const v =  make<homogeneous_vector<T>>(deque.begin(), std::next(deque.begin(), size));
+        deque.erase(deque.begin(), std::next(deque.begin(), size));
         return v;
       }
     }
diff --git a/include/meevax/memory/collector.hpp b/include/meevax/memory/collector.hpp
index d9a7d2fc9..e8e9dec6e 100644
--- a/include/meevax/memory/collector.hpp
+++ b/include/meevax/memory/collector.hpp
@@ -85,7 +85,7 @@ inline namespace memory
         {
           return cache;
         }
-        else if (auto iter = headers.lower_bound(reinterpret_cast<memory::header *>(data)); iter != std::begin(headers) and (*--iter)->contains(data))
+        else if (auto iter = headers.lower_bound(reinterpret_cast<memory::header *>(data)); iter != headers.begin() and (*--iter)->contains(data))
         {
           return *iter;
         }
diff --git a/include/meevax/utility/hexdump.hpp b/include/meevax/utility/hexdump.hpp
index bc80f344a..da7a1227e 100644
--- a/include/meevax/utility/hexdump.hpp
+++ b/include/meevax/utility/hexdump.hpp
@@ -40,8 +40,8 @@ inline namespace utility
     // TODO UPDATE WITH STD::ENDIAN (C++20)
     auto operator()(std::ostream & os) const -> std::ostream &
     {
-      for (auto iter = std::rbegin(data); iter != std::rend(data); ++iter) // little endian
-      // for (auto iter = std::begin(data); iter != std::end(data); ++iter) // big endian
+      for (auto iter = data.rbegin(); iter != data.rend(); ++iter) // little endian
+      // for (auto iter = data.begin(); iter != data.end(); ++iter) // big endian
       {
         os << std::setw(2) << std::setfill('0') << std::hex << static_cast<unsigned int>(*iter) << " ";
       }
diff --git a/src/kernel/boot.cpp b/src/kernel/boot.cpp
index 0dd39c821..605ff0ba1 100644
--- a/src/kernel/boot.cpp
+++ b/src/kernel/boot.cpp
@@ -847,27 +847,27 @@ inline namespace kernel
 
       library.define<procedure>("=", [](let const& xs)
       {
-        return std::adjacent_find(std::begin(xs), std::end(xs), not_equals) == std::end(xs);
+        return std::adjacent_find(xs.begin(), xs.end(), not_equals) == xs.end();
       });
 
       library.define<procedure>("<", [](let const& xs)
       {
-        return std::adjacent_find(std::begin(xs), std::end(xs), greater_than_or_equals) == std::end(xs);
+        return std::adjacent_find(xs.begin(), xs.end(), greater_than_or_equals) == xs.end();
       });
 
       library.define<procedure>("<=", [](let const& xs)
       {
-        return std::adjacent_find(std::begin(xs), std::end(xs), greater_than) == std::end(xs);
+        return std::adjacent_find(xs.begin(), xs.end(), greater_than) == xs.end();
       });
 
       library.define<procedure>(">", [](let const& xs)
       {
-        return std::adjacent_find(std::begin(xs), std::end(xs), less_than_or_equals) == std::end(xs);
+        return std::adjacent_find(xs.begin(), xs.end(), less_than_or_equals) == xs.end();
       });
 
       library.define<procedure>(">=", [](let const& xs)
       {
-        return std::adjacent_find(std::begin(xs), std::end(xs), less_than) == std::end(xs);
+        return std::adjacent_find(xs.begin(), xs.end(), less_than) == xs.end();
       });
 
       library.define<procedure>("zero?", [](let const& xs)
@@ -907,19 +907,19 @@ inline namespace kernel
 
       library.define<procedure>("+", [](let const& xs)
       {
-        return std::accumulate(std::begin(xs), std::end(xs), e0, std::plus());
+        return std::accumulate(xs.begin(), xs.end(), e0, std::plus());
       });
 
       library.define<procedure>("*", [](let const& xs)
       {
-        return std::accumulate(std::begin(xs), std::end(xs), e1, std::multiplies());
+        return std::accumulate(xs.begin(), xs.end(), e1, std::multiplies());
       });
 
       library.define<procedure>("-", [](let const& xs)
       {
         if (cdr(xs).is<pair>())
         {
-          return std::accumulate(std::next(std::begin(xs)), std::end(xs), xs[0], std::minus());
+          return std::accumulate(std::next(xs.begin()), xs.end(), xs[0], std::minus());
         }
         else
         {
@@ -931,7 +931,7 @@ inline namespace kernel
       {
         if (cdr(xs).is<pair>())
         {
-          return std::accumulate(std::next(std::begin(xs)), std::end(xs), xs[0], std::divides());
+          return std::accumulate(std::next(xs.begin()), xs.end(), xs[0], std::divides());
         }
         else
         {
diff --git a/src/kernel/environment.cpp b/src/kernel/environment.cpp
index 725d1df09..c5a8d8fce 100644
--- a/src/kernel/environment.cpp
+++ b/src/kernel/environment.cpp
@@ -206,7 +206,7 @@ inline namespace kernel
       return rename(cadr(form))
                    (cddr(form));
     }
-    else if (auto iter = libraries().find(lexical_cast<std::string>(form)); iter != std::end(libraries()))
+    else if (auto iter = libraries().find(lexical_cast<std::string>(form)); iter != libraries().end())
     {
       return std::get<1>(*iter).resolve();
     }
diff --git a/src/kernel/implementation_dependent.cpp b/src/kernel/implementation_dependent.cpp
index 421e54113..acaa6eedb 100644
--- a/src/kernel/implementation_dependent.cpp
+++ b/src/kernel/implementation_dependent.cpp
@@ -27,15 +27,17 @@ inline namespace kernel
     {
       if (car(requirement).as<symbol>() == "library")
       {
-        return libraries().find(lexical_cast<std::string>(cadr(requirement))) != std::end(libraries());
+        return libraries().find(lexical_cast<std::string>(cadr(requirement))) != libraries().end();
       }
       else if (car(requirement).as<symbol>() == "and")
       {
-        return std::all_of(std::begin(cdr(requirement)), std::end(cdr(requirement)), test);
+        return std::all_of(cdr(requirement).begin(),
+                           cdr(requirement).end(), test);
       }
       else if (car(requirement).as<symbol>() == "or")
       {
-        return std::any_of(std::begin(cdr(requirement)), std::end(cdr(requirement)), test);
+        return std::any_of(cdr(requirement).begin(),
+                           cdr(requirement).end(), test);
       }
       else if (car(requirement).as<symbol>() == "not")
       {
diff --git a/src/kernel/number.cpp b/src/kernel/number.cpp
index 0b227bbb5..eee4e2efd 100644
--- a/src/kernel/number.cpp
+++ b/src/kernel/number.cpp
@@ -463,7 +463,7 @@ inline namespace kernel
 
       auto static const pattern = std::regex(R"(([+-]?(?:\d+\.?|\d*\.\d+))([DEFLSdefls][+-]?\d+)?)");
 
-      if (auto iter = constants.find(literal); iter != std::end(constants))
+      if (auto iter = constants.find(literal); iter != constants.end())
       {
         return make(iter->second);
       }
diff --git a/src/kernel/string.cpp b/src/kernel/string.cpp
index faac4c640..8a6cc8f87 100644
--- a/src/kernel/string.cpp
+++ b/src/kernel/string.cpp
@@ -52,8 +52,8 @@ inline namespace kernel
 
   auto operator ==(string const& s1, string const& s2) -> bool
   {
-    return std::equal(std::begin(s1.vector), std::end(s1.vector),
-                      std::begin(s2.vector), std::end(s2.vector));
+    return std::equal(s1.vector.begin(), s1.vector.end(),
+                      s2.vector.begin(), s2.vector.end());
   }
 
   auto operator <<(std::ostream & os, string const& datum) -> std::ostream &
diff --git a/src/kernel/symbol.cpp b/src/kernel/symbol.cpp
index e0c44eceb..0426dad78 100644
--- a/src/kernel/symbol.cpp
+++ b/src/kernel/symbol.cpp
@@ -59,7 +59,7 @@ inline namespace kernel
 
   auto make_symbol(std::string const& name) -> object const&
   {
-    if (auto const iter = symbols().find(name); iter != std::end(symbols()))
+    if (auto const iter = symbols().find(name); iter != symbols().end())
     {
       return iter->second;
     }
diff --git a/src/kernel/textual_input_port.cpp b/src/kernel/textual_input_port.cpp
index 9fba2fba0..7b3de16ed 100644
--- a/src/kernel/textual_input_port.cpp
+++ b/src/kernel/textual_input_port.cpp
@@ -264,7 +264,7 @@ inline namespace kernel
           case '#':
             ignore(1);
 
-            if (auto iter = datum_labels.find(label); iter != std::end(datum_labels))
+            if (auto iter = datum_labels.find(label); iter != datum_labels.end())
             {
               return iter->second;
             }
@@ -497,7 +497,7 @@ inline namespace kernel
 
       auto name = static_cast<std::string>(character(c)) + take_token();
 
-      if (auto iter = names.find(name); iter != std::end(names))
+      if (auto iter = names.find(name); iter != names.end())
       {
         return character(iter->second);
       }
diff --git a/src/kernel/vector.cpp b/src/kernel/vector.cpp
index ada6da730..4beeb73e6 100644
--- a/src/kernel/vector.cpp
+++ b/src/kernel/vector.cpp
@@ -27,7 +27,7 @@ inline namespace kernel
 {
   heterogeneous_vector::heterogeneous_vector(object const& x)
   {
-    std::copy(std::begin(x), std::end(x), std::back_inserter(vector));
+    std::copy(x.begin(), x.end(), std::back_inserter(vector));
   }
 
   heterogeneous_vector::heterogeneous_vector(std::size_t size, object const& x)
@@ -46,8 +46,8 @@ inline namespace kernel
 
   auto operator ==(heterogeneous_vector const& v, heterogeneous_vector const& u) -> bool
   {
-    return std::equal(std::begin(v.vector), std::end(v.vector),
-                      std::begin(u.vector), std::end(u.vector), equal);
+    return std::equal(v.vector.begin(), v.vector.end(),
+                      u.vector.begin(), u.vector.end(), equal);
   }
 
   auto operator <<(std::ostream & output, heterogeneous_vector const& datum) -> std::ostream &
diff --git a/test/list.cpp b/test/list.cpp
index 3a0f928d6..c67f8911a 100644
--- a/test/list.cpp
+++ b/test/list.cpp
@@ -33,7 +33,7 @@ auto main() -> int
   {
     let x = list(a, b, c);
 
-    for (auto iter = std::begin(x); iter != std::end(x); ++iter)
+    for (auto iter = x.begin(); iter != x.end(); ++iter)
     {
       assert((*iter).template is<symbol>());
     }
@@ -42,18 +42,16 @@ auto main() -> int
   {
     let x = list(a, b, c);
 
-    for (auto iter = std::begin(x); iter != std::end(x); ++iter)
+    for (auto iter = x.begin(); iter != x.end(); ++iter)
     {
       assert(iter->template is<symbol>());
     }
   }
 
   {
-    let x = list(a, b);
-    cddr(x) = x;
+    let x = circular_list(a, b);
 
-    let y = list(a, b, a, b);
-    cddddr(y) = y;
+    let y = circular_list(a, b, a, b);
 
     assert(equal(x, y));
   }

From 10f0155370962520cc4a5c6d3d66e32759bf0ddf Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Tue, 24 Oct 2023 22:47:14 +0900
Subject: [PATCH 31/31] Remove unused header file `unsigned_integer_set.hpp`

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md                                     |   6 +-
 VERSION                                       |   2 +-
 .../meevax/memory/unsigned_integer_set.hpp    | 200 ------------------
 3 files changed, 4 insertions(+), 204 deletions(-)
 delete mode 100644 include/meevax/memory/unsigned_integer_set.hpp

diff --git a/README.md b/README.md
index 5c2e7dc26..dcf19d464 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.62_amd64.deb
+sudo apt install build/meevax_0.5.63_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.62.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.63.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.62_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.63_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index 1efaf43fe..08c80f334 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.62
+0.5.63
diff --git a/include/meevax/memory/unsigned_integer_set.hpp b/include/meevax/memory/unsigned_integer_set.hpp
deleted file mode 100644
index 79c516e09..000000000
--- a/include/meevax/memory/unsigned_integer_set.hpp
+++ /dev/null
@@ -1,200 +0,0 @@
-/*
-   Copyright 2018-2023 Tatsuya Yamasaki.
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
-
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
-*/
-
-#ifndef INCLUDED_MEEVAX_MEMORY_UNSIGNED_INTEGER_SET_HPP
-#define INCLUDED_MEEVAX_MEMORY_UNSIGNED_INTEGER_SET_HPP
-
-#include <algorithm>
-#include <cstdint>
-#include <iterator>
-#include <limits>
-#include <vector>
-
-namespace meevax
-{
-inline namespace memory
-{
-  template <typename N>
-  constexpr auto log2(N n) -> std::size_t
-  {
-    return n <= 2 ? 1 : log2(n / 2) + 1;
-  }
-
-  class unsigned_integer_set
-  {
-    std::size_t size;
-
-    std::vector<std::uint64_t> data;
-
-    static constexpr auto digits = std::numeric_limits<std::uint64_t>::digits;
-
-    constexpr auto index_of(std::size_t value)
-    {
-      return value / digits;
-    };
-
-    constexpr auto mark_of(std::size_t value)
-    {
-      return static_cast<std::uint64_t>(1) << (value - digits * index_of(value));
-    };
-
-  public:
-    struct iterator
-    {
-      using iterator_category = std::forward_iterator_tag;
-
-      using value_type = std::uint64_t;
-
-      using difference_type = std::ptrdiff_t;
-
-      std::uint64_t const* data;
-
-      std::size_t size;
-
-      std::size_t index;
-
-      std::size_t bit;
-
-      explicit iterator(std::vector<std::uint64_t> const& bitset)
-        : data { bitset.data() }
-        , size { bitset.size() }
-        , index { 0 }
-        , bit { 0 }
-      {
-        if (not valid())
-        {
-          operator ++();
-        }
-      }
-
-      explicit iterator()
-        : data { nullptr }
-        , size { 0 }
-        , index { std::numeric_limits<std::size_t>::max() }
-        , bit { 0 }
-      {}
-
-      auto valid() const -> bool
-      {
-        return (data[index] >> bit) & 1;
-      }
-
-      auto operator *() const
-      {
-        return index * digits + bit;
-      }
-
-      auto operator ++() -> iterator &
-      {
-        do
-        {
-          if (digits <= ++bit)
-          {
-            bit = 0;
-
-            if (size <= ++index)
-            {
-              index = std::numeric_limits<std::size_t>::max();
-              return *this;
-            }
-          }
-        }
-        while (not valid());
-
-        return *this;
-      }
-
-      auto operator ++(int) -> auto
-      {
-        auto copy = *this;
-        operator ++();
-        return copy;
-      }
-
-      auto operator ==(iterator const& rhs)
-      {
-        return index == rhs.index and bit == rhs.bit;
-      }
-
-      auto operator !=(iterator const& rhs)
-      {
-        return not operator ==(rhs);
-      }
-    };
-
-    explicit unsigned_integer_set()
-      : size { 0 }
-      , data {}
-    {}
-
-    auto resize(std::size_t given_size)
-    {
-      size = given_size;
-      data.resize(size / digits + 1);
-    }
-
-    auto insert(std::uint64_t value)
-    {
-      if (data.size() < index_of(value))
-      {
-        resize(value);
-      }
-
-      data[index_of(value)] |= mark_of(value);
-    }
-
-    auto erase(std::uint64_t value)
-    {
-      data[index_of(value)] &= ~mark_of(value);
-    }
-
-    auto erase(iterator iter)
-    {
-      erase(*iter);
-      return ++iter;
-    }
-
-    auto clear()
-    {
-      std::fill(std::begin(data), std::end(data), 0);
-    }
-
-    auto begin() const
-    {
-      return iterator(data);
-    }
-
-    auto end() const
-    {
-      return iterator();
-    }
-
-    template <typename... Ts>
-    auto lower_bound(Ts&&... xs)
-    {
-      return std::lower_bound(begin(), end(), std::forward<decltype(xs)>(xs)...);
-    }
-
-    template <typename... Ts>
-    auto upper_bound(Ts&&... xs)
-    {
-      return std::upper_bound(begin(), end(), std::forward<decltype(xs)>(xs)...);
-    }
-  };
-} // namespace memory
-} // namespace meevax
-
-#endif // INCLUDED_MEEVAX_MEMORY_UNSIGNED_INTEGER_SET_HPP