Add C and Ruby Extension Example Mixed

doc/mrbgems/c_and_ruby_extension_example/Makefile

@@ -0,0 +1,12 @@
+include ../../Makefile4gem
+
+GEM := c_and_ruby_extension_example
+
+GEM_C_FILES := $(wildcard $(SRC_DIR)/*.c)
+GEM_OBJECTS := $(patsubst %.c, %.o, $(GEM_C_FILES))
+
+GEM_RB_FILES := $(wildcard $(MRB_DIR)/*.rb)
+
+gem-all : $(GEM_OBJECTS) gem-c-and-rb-files
+
+gem-clean : gem-clean-c-and-rb-files

doc/mrbgems/c_and_ruby_extension_example/README.md

@@ -0,0 +1,4 @@
+C and Ruby Extension Example
+=========
+
+This is an example gem which implements a C and Ruby extension.

doc/mrbgems/c_and_ruby_extension_example/mrblib/example.rb

@@ -0,0 +1,5 @@
+class RubyExtension
+  def CRubyExtension.ruby_method
+    puts "A Ruby Extension"
+  end
+end

doc/mrbgems/c_and_ruby_extension_example/src/example.c

@@ -0,0 +1,17 @@
+#include <mruby.h>
+#include <stdio.h>
+
+static struct RClass *_class_cextension;
+
+static mrb_value
+mrb_c_method(mrb_state *mrb, mrb_value self)
+{
+  puts("A C Extension");
+  return self;
+}
+
+void
+mrb_c_and_ruby_extension_example_gem_init(mrb_state* mrb) {
+  _class_cextension = mrb_define_module(mrb, "CRubyExtension");
+  mrb_define_class_method(mrb, _class_cextension, "c_method", mrb_c_method, ARGS_NONE());
+}

doc/mrbgems/c_and_ruby_extension_example/test/example.rb

@@ -0,0 +1,7 @@
+assert('C and Ruby Extension Example 1') do
+  CRubyExtension.respond_to? :c_method
+end
+
+assert('C and Ruby Extension Example 2') do
+  CRubyExtension.respond_to? :ruby_method
+end