Merge pull request #573 from skandhas/pr-add-Module-module_eval

add "Module#module_eval" and "Module#class_eval" for mruby

src/class.c

@@ -848,6 +848,32 @@ mrb_mod_instance_methods(mrb_state *mrb, mrb_value mod)
   return class_instance_method_list(mrb, argc, argv, c, 0);
 }
 
+mrb_value mrb_yield_internal(mrb_state *mrb, mrb_value b, int argc, mrb_value *argv, mrb_value self, struct RClass *c);
+
+/* 15.2.2.4.35 */
+/*
+ *  call-seq:
+ *     mod.class_eval {| | block }  -> obj
+ *     mod.module_eval {| | block } -> obj
+ *
+ *  Evaluates block in the context of _mod_. This can
+ *  be used to add methods to a class. <code>module_eval</code> returns
+ *  the result of evaluating its argument.
+ */
+
+mrb_value
+mrb_mod_module_eval(mrb_state *mrb, mrb_value mod)
+{
+  mrb_value a, b;
+  struct RClass *c;
+
+  if (mrb_get_args(mrb, "|S&", &a, &b) == 1) {
+    mrb_raise(mrb, E_NOTIMP_ERROR, "module_eval/class_eval with string not implemented");
+  }
+  c = mrb_class_ptr(mod);
+  return mrb_yield_internal(mrb, b, 0, 0, mod, c);
+}
+
 mrb_value
 mrb_singleton_class(mrb_state *mrb, mrb_value v)
 {
@@ -1504,9 +1530,11 @@ mrb_init_class(mrb_state *mrb)
   mrb_define_method(mrb, mod, "include", mrb_mod_include, ARGS_ANY());               /* 15.2.2.4.27 */
   mrb_define_method(mrb, mod, "include?", mrb_mod_include_p, ARGS_REQ(1));           /* 15.2.2.4.28 */
   mrb_define_method(mrb, mod, "append_features", mrb_mod_append_features, ARGS_REQ(1)); /* 15.2.2.4.10 */
-  mrb_define_method(mrb, mod, "included", mrb_bob_init, ARGS_REQ(1));                /* 15.2.2.4.29 */
+  mrb_define_method(mrb, mod, "class_eval", mrb_mod_module_eval, ARGS_ANY());           /* 15.2.2.4.15 */
+  mrb_define_method(mrb, mod, "included", mrb_bob_init, ARGS_REQ(1));                     /* 15.2.2.4.29 */
   mrb_define_method(mrb, mod, "included_modules", mrb_mod_included_modules, ARGS_NONE()); /* 15.2.2.4.30 */
   mrb_define_method(mrb, mod, "instance_methods", mrb_mod_instance_methods, ARGS_ANY());  /* 15.2.2.4.33 */
+  mrb_define_method(mrb, mod, "module_eval", mrb_mod_module_eval, ARGS_ANY());            /* 15.2.2.4.35 */
 
   mrb_define_method(mrb, mod, "to_s", mrb_mod_to_s, ARGS_NONE());
   mrb_define_method(mrb, mod, "inspect", mrb_mod_to_s, ARGS_NONE());

test/t/module.rb

@@ -31,6 +31,22 @@ assert('Module#append_features', '15.2.2.4.10') do
   Test4AppendFeatures2.const_get(:Const4AppendFeatures2) == Test4AppendFeatures2
 end
 
+assert('Module#class_eval', '15.2.2.4.15') do
+  class Test4ClassEval
+    @a = 11
+    @b = 12
+  end
+  Test4ClassEval.class_eval do
+    def method1
+    end
+  end
+  r = Test4ClassEval.instance_methods
+  Test4ClassEval.class_eval{ @a } == 11 and
+  Test4ClassEval.class_eval{ @b } == 12 and
+  r.class == Array and r.include?(:method1)
+end
+
+
 assert('Module#class_variables', '15.2.2.4.19') do
   class Test4ClassVariables1
     @@var1 = 1
@@ -151,6 +167,14 @@ assert('Module#instance_methods', '15.2.2.4.33') do
    r.class == Array and r.include?(:method3) and r.include?(:method2)
 end
 
+assert('Module#module_eval', '15.2.2.4.35') do
+   module Test4ModuleEval
+     @a = 11
+     @b = 12
+   end
+   Test4ModuleEval.module_eval{ @a } == 11 and
+   Test4ModuleEval.module_eval{ @b } == 12
+end
 
 # Not ISO specified