Added other methods for `Binding`

- Added to `mruby-binding-core`
  - `Binding#local_variable_defined?`
  - `Binding#local_variable_get`
  - `Binding#local_variable_set`
  - `Binding#local_variables`
  - `Binding#receiver`
  - `Binding#source_location`
  - `Binding#inspect`
- Added to `mruby-proc-binding`
  - `Proc#binding`

The reason for separating `Proc#binding` is that core-mrbgems has a method that returns a closure object to minimize possible problems with being able to manipulate internal variables.
By separating it as different mrbgem, each user can judge this problem and incorporate it arbitrarily.

4 files changed, 97 insertions, 0 deletions

diff --git a/mrbgems/mruby-proc-binding/mrbgem.rake b/mrbgems/mruby-proc-binding/mrbgem.rake
new file mode 100644
index 000000000..425aac847
--- /dev/null
+++ b/mrbgems/mruby-proc-binding/mrbgem.rake
@@ -0,0 +1,9 @@
+MRuby::Gem::Specification.new('mruby-proc-binding') do |spec|
+  spec.license = 'MIT'
+  spec.author  = 'mruby developers'
+  spec.summary = 'Proc#binding method'
+
+  spec.add_dependency('mruby-binding-core', :core => 'mruby-binding-core')
+  spec.add_test_dependency('mruby-binding', :core => 'mruby-binding')
+  spec.add_test_dependency('mruby-compiler', :core => 'mruby-compiler')
+end
diff --git a/mrbgems/mruby-proc-binding/src/proc-binding.c b/mrbgems/mruby-proc-binding/src/proc-binding.c
new file mode 100644
index 000000000..82d9d1d51
--- /dev/null
+++ b/mrbgems/mruby-proc-binding/src/proc-binding.c
@@ -0,0 +1,52 @@
+#include <mruby.h>
+#include <mruby/presym.h>
+#include <mruby/proc.h>
+#include <mruby/variable.h>
+
+void mrb_proc_merge_lvar(mrb_state *mrb, mrb_irep *irep, struct REnv *env, int num, const mrb_sym *lv, const mrb_value *stack);
+
+/* provided by mruby-proc-ext */
+mrb_value mrb_proc_source_location(mrb_state *mrb, struct RProc *p);
+
+/* provided by mruby-binding-core */
+mrb_value mrb_binding_alloc(mrb_state *mrb);
+struct RProc *mrb_binding_wrap_lvspace(mrb_state *mrb, const struct RProc *proc, struct REnv **envp);
+
+static mrb_value
+mrb_proc_binding(mrb_state *mrb, mrb_value procval)
+{
+  mrb_value binding = mrb_binding_alloc(mrb);
+  const struct RProc *proc = mrb_proc_ptr(procval);
+  struct REnv *env;
+
+  mrb_value receiver;
+  if (!proc || MRB_PROC_CFUNC_P(proc) || !proc->upper || MRB_PROC_CFUNC_P(proc->upper)) {
+    env = NULL;
+    proc = NULL;
+    receiver = mrb_nil_value();
+  }
+  else {
+    env = MRB_PROC_ENV(proc);
+    mrb_assert(env);
+    proc = proc->upper;
+    receiver = MRB_ENV_LEN(env) > 0 ? env->stack[0] : mrb_nil_value();
+  }
+
+  proc = mrb_binding_wrap_lvspace(mrb, proc, &env);
+  mrb_iv_set(mrb, binding, MRB_SYM(proc), mrb_obj_value((void *)proc));
+  mrb_iv_set(mrb, binding, MRB_SYM(recv), receiver);
+  mrb_iv_set(mrb, binding, MRB_SYM(env), mrb_obj_value(env));
+  mrb_iv_set(mrb, binding, MRB_SYM(source_location), mrb_proc_source_location(mrb, mrb_proc_ptr(procval)));
+  return binding;
+}
+
+void
+mrb_mruby_proc_binding_gem_init(mrb_state *mrb)
+{
+  mrb_define_method(mrb, mrb->proc_class, "binding", mrb_proc_binding, MRB_ARGS_NONE());
+}
+
+void
+mrb_mruby_proc_binding_gem_final(mrb_state *mrb)
+{
+}
diff --git a/mrbgems/mruby-proc-binding/test/proc-binding.c b/mrbgems/mruby-proc-binding/test/proc-binding.c
new file mode 100644
index 000000000..ec071b920
--- /dev/null
+++ b/mrbgems/mruby-proc-binding/test/proc-binding.c
@@ -0,0 +1,14 @@
+#include <mruby.h>
+#include <mruby/compile.h>
+
+static mrb_value
+proc_in_c(mrb_state *mrb, mrb_value self)
+{
+  return mrb_load_string(mrb, "proc { |a, b| a + b }");
+}
+
+void
+mrb_mruby_proc_binding_gem_test(mrb_state *mrb)
+{
+  mrb_define_method(mrb, mrb->object_class, "proc_in_c", proc_in_c, MRB_ARGS_NONE());
+}
diff --git a/mrbgems/mruby-proc-binding/test/proc-binding.rb b/mrbgems/mruby-proc-binding/test/proc-binding.rb
new file mode 100644
index 000000000..b28d8b1dd
--- /dev/null
+++ b/mrbgems/mruby-proc-binding/test/proc-binding.rb
@@ -0,0 +1,22 @@
+assert "Proc#binding" do
+  block = ->(i) {}
+  a, b, c = 1, 2, 3
+  bind = block.binding
+  assert_equal([:a, :b, :bind, :block, :c], bind.local_variables.sort)
+  assert_equal(1, bind.local_variable_get(:a))
+  assert_equal(5, bind.eval("b + c"))
+  bind.local_variable_set(:x, 9)
+  assert_equal(9, bind.local_variable_get(:x))
+end
+
+assert("Binding#source_location after Proc#binding") do
+  skip unless -> {}.source_location
+
+  block, source_location = -> {}, [__FILE__, __LINE__]
+  assert_equal source_location, block.binding.source_location
+end
+
+assert "Proc#binding and .eval from C" do
+  bind = proc_in_c.binding
+  assert_nothing_raised { bind.eval("self") }
+end