Cleanup member function environment::evaluate

Signed-off-by: yamacir-kit <[email protected]>

README.md

@@ -90,7 +90,7 @@ 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_0.5.195_amd64.deb
+sudo apt install build/meevax_0.5.196_amd64.deb
 ```
 
 or
@@ -122,9 +122,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.195.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.196.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.195_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.196_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage

VERSION

@@ -1 +1 @@
-0.5.195
+0.5.196

src/kernel/environment.cpp

@@ -73,24 +73,37 @@ inline namespace kernel
 
        in the REPL.
     */
-    if (s or e or c)
+    struct dump
     {
-      d = cons(std::exchange(s, nullptr),
-               std::exchange(e, nullptr),
-               std::exchange(c, nullptr), d);
-    }
+      environment & registers;
 
-    let const result = execute(optimize(compile(expression)));
+      let s, e, c, d;
 
-    if (d)
-    {
-      s = head(d, 0);
-      e = head(d, 1);
-      c = head(d, 2);
-      d = tail(d, 3);
-    }
+      explicit dump(environment & registers)
+        : registers { registers }
+        , s { std::exchange(registers.s, nullptr) }
+        , e { std::exchange(registers.e, nullptr) }
+        , c { std::exchange(registers.c, nullptr) }
+        , d { std::exchange(registers.d, nullptr) }
+      {}
+
+      ~dump()
+      {
+        std::invoke(*this);
+      }
+
+      auto operator ()() -> void
+      {
+        registers.s = s;
+        registers.e = e;
+        registers.c = c;
+        registers.d = d;
+      }
+    };
+
+    auto undump = dump(*this);
 
-    return result;
+    return execute(optimize(compile(expression)));
   }
   catch (object const& x)
   {

src/kernel/number.cpp

@@ -18,6 +18,7 @@
 #include <regex>
 #include <string_view>
 
+#include <meevax/kernel/error.hpp>
 #include <meevax/kernel/ghost.hpp>
 #include <meevax/kernel/number.hpp>
 #include <meevax/kernel/string.hpp>
@@ -314,7 +315,7 @@ inline namespace kernel
     }
     else
     {
-      throw std::domain_error("not an number");
+      throw error(make<string>("not an number"));
     }
   }
 
@@ -332,7 +333,7 @@ inline namespace kernel
     }
     else
     {
-      throw std::domain_error("not an number");
+      throw error(make<string>("not an number"));
     }
   }