implement rb_obj_is_proc

CHANGELOG.md

@@ -52,6 +52,7 @@ Compatibility:
 * Fixed uninitialized variable warnings in core and lib (#1897).
 * Make `Thread#backtrace` support omit, length and range arguments.
 * Implemented `Range#%`.
+* Implemented `rb_obj_is_proc` (#1908, @kipply, @XrXr). 
 * Fixed the type of the `flags` field of `rb_data_type_t` (#1911).
 
 Changes:

spec/ruby/optional/capi/ext/proc_spec.c

@@ -23,6 +23,10 @@ VALUE proc_spec_rb_proc_call(VALUE self, VALUE prc, VALUE args) {
   return rb_proc_call(prc, args);
 }
 
+VALUE proc_spec_rb_obj_is_proc(VALUE self, VALUE prc) {
+  return rb_obj_is_proc(prc);
+}
+
 /* This helper is not strictly necessary but reflects the code in wxRuby that
  * originally exposed issues with this Proc.new behavior.
  */
@@ -61,6 +65,7 @@ void Init_proc_spec(void) {
   rb_define_method(cls, "rb_proc_arity", proc_spec_rb_proc_arity, 1);
   rb_define_method(cls, "rb_proc_call", proc_spec_rb_proc_call, 2);
   rb_define_method(cls, "rb_Proc_new", proc_spec_rb_Proc_new, 1);
+  rb_define_method(cls, "rb_obj_is_proc", proc_spec_rb_obj_is_proc, 1);
 }
 
 #ifdef __cplusplus

spec/ruby/optional/capi/proc_spec.rb

@@ -54,6 +54,25 @@
       @p.rb_proc_call(prc, [6, 7]).should == 42
     end
   end
+
+  describe "rb_obj_is_proc" do
+    it "returns true for Proc" do
+      prc = Proc.new {|a,b| a * b }
+      @p.rb_obj_is_proc(prc).should be_true
+    end
+
+    it "returns true for subclass of Proc" do
+      prc = Class.new(Proc).new {}
+      @p.rb_obj_is_proc(prc).should be_true
+    end
+
+    it "returns false for non Proc instances" do
+      @p.rb_obj_is_proc("aoeui").should be_false
+      @p.rb_obj_is_proc(123).should be_false
+      @p.rb_obj_is_proc(true).should be_false
+      @p.rb_obj_is_proc([]).should be_false
+    end
+  end
 end
 
 describe "C-API when calling Proc.new from a C function" do

src/main/c/cext/ruby.c

@@ -3885,7 +3885,7 @@ VALUE rb_require_safe(VALUE fname, int safe) {
 }
 
 VALUE rb_obj_is_proc(VALUE proc) {
-  rb_tr_error("rb_obj_is_proc not implemented");
+  return rb_obj_is_kind_of(proc, rb_cProc);
 }
 
 VALUE rb_proc_call_with_block(VALUE self, int argc, const VALUE *argv, VALUE pass_procval) {