From a7fabc471358abc9487df35dfabd669eb63692ff Mon Sep 17 00:00:00 2001
From: yamacir-kit <httperror@404-notfound.jp>
Date: Wed, 25 Dec 2024 02:46:44 +0900
Subject: [PATCH] Cleanup member function `syntactic_environment::identify`

Signed-off-by: yamacir-kit <httperror@404-notfound.jp>
---
 README.md                                     |  4 +--
 VERSION                                       |  2 +-
 .../meevax/kernel/syntactic_environment.hpp   | 35 +++++++++----------
 3 files changed, 20 insertions(+), 21 deletions(-)

diff --git a/README.md b/README.md
index a28bbbfa0..28e9f39d9 100644
--- a/README.md
+++ b/README.md
@@ -98,9 +98,9 @@ Then, select one of the following targets and `make` it according to your purpos
 
 | Target      | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.309.so` and executable `meevax`.
+| `all`       | Build shared-library `libmeevax.0.5.310.so` and executable `meevax`.
 | `install`   | Copy files into `/usr/local` directly.
-| `package`   | Generate debian package `meevax_0.5.309_amd64.deb` (only Ubuntu). The generated package can be installed by `sudo apt install build/meevax_0.5.309_amd64.deb`.
+| `package`   | Generate debian package `meevax_0.5.310_amd64.deb` (only Ubuntu). The generated package can be installed by `sudo apt install build/meevax_0.5.310_amd64.deb`.
 | `test`      | Test executable `meevax`. This target requires Valgrind to be installed.
 | `uninstall` | Remove files copied to `/usr/local` directly by target `install`.
 
diff --git a/VERSION b/VERSION
index 828c6602a..51794f488 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.309
+0.5.310
diff --git a/include/meevax/kernel/syntactic_environment.hpp b/include/meevax/kernel/syntactic_environment.hpp
index a5cd19793..944a7e86b 100644
--- a/include/meevax/kernel/syntactic_environment.hpp
+++ b/include/meevax/kernel/syntactic_environment.hpp
@@ -933,37 +933,38 @@ namespace meevax::inline kernel
     {
       assert(variable.is_also<identifier>());
 
-      auto i = 0;
-
-      for (auto outer = bound_variables; outer.is<pair>(); ++i, outer = cdr(outer))
+      for (auto i = 0; let formals : bound_variables)
       {
-        auto j = 0;
-
-        for (auto inner = outer.is<pair>() ? car(outer) : unit; not inner.is<null>(); ++j, inner = inner.is<pair>() ? cdr(inner) : unit)
+        for (auto j = 0; not formals.is<null>(); formals = cdr(formals))
         {
-          if (inner.is<pair>())
+          if (formals.is<pair>())
           {
-            if (car(inner).is<absolute>() and eq(caar(inner), variable))
+            if (car(formals).is<absolute>() and eq(caar(formals), variable))
             {
-              return car(inner);
+              return car(formals);
             }
-            else if (eq(car(inner), variable))
+            else if (eq(car(formals), variable))
             {
               return make<relative>(make<std::int32_t>(i), make<std::int32_t>(j));
             }
           }
-          else if (inner.is_also<identifier>() and eq(inner, variable))
+          else if (formals.is_also<identifier>() and eq(formals, variable))
           {
             return make<variadic>(make<std::int32_t>(i), make<std::int32_t>(j));
           }
+
+          ++j;
         }
+
+        ++i;
       }
 
-      if (variable.is<syntactic_closure>()) // Resolve alias
+      if (variable.is<syntactic_closure>() and
+          variable.as<syntactic_closure>().form.template is_also<identifier>()) // if is an alias
       {
         return variable.as<syntactic_closure>()
                        .environment
-                       .template as<syntactic_environment>()
+                       .template as_const<syntactic_environment>()
                        .identify(variable.as<syntactic_closure>().form,
                                  unify(car(variable.as<syntactic_closure>().environment),
                                        bound_variables));
@@ -977,11 +978,9 @@ namespace meevax::inline kernel
     inline auto identify(object const& variable,
                          object const& bound_variables)
     {
-      if (not variable.is_also<identifier>())
-      {
-        return f;
-      }
-      else if (let const& identity = std::as_const(*this).identify(variable, bound_variables); identity != f)
+      assert(variable.is_also<identifier>());
+
+      if (let const& identity = std::as_const(*this).identify(variable, bound_variables); identity != f)
       {
         return identity;
       }