From 16b174dd46e4698103de916e69e465984cb05a67 Mon Sep 17 00:00:00 2001
From: Mark Dodwell <mark@mkdynamic.co.uk>
Date: Wed, 4 Jul 2012 02:14:00 -0700
Subject: [PATCH] Add Kernel#Symbol conversion method like String(), Array()
 etc.

---
 include/ruby/intern.h    |  1 +
 object.c                 | 24 ++++++++++++++++++++++++
 test/ruby/test_object.rb | 10 ++++++++++
 3 files changed, 35 insertions(+)

diff --git a/include/ruby/intern.h b/include/ruby/intern.h
index e5167c6..327c0d1 100644
--- a/include/ruby/intern.h
+++ b/include/ruby/intern.h
@@ -557,6 +557,7 @@ VALUE rb_Float(VALUE);
 VALUE rb_String(VALUE);
 VALUE rb_Array(VALUE);
 VALUE rb_Hash(VALUE);
+VALUE rb_Symbol(VALUE);
 double rb_cstr_to_dbl(const char*, int);
 double rb_str_to_dbl(VALUE, int);
 /* parse.y */
diff --git a/object.c b/object.c
index f890d49..695fdbe 100644
--- a/object.c
+++ b/object.c
@@ -2662,6 +2662,29 @@ rb_f_hash(VALUE obj, VALUE arg)
 }
 
 /*
+ *  call-seq:
+ *     Symbol(arg)   -> Symbol
+ *
+ *  Converts <i>arg</i> to a <code>Symbol</code> by calling its
+ *  <code>to_sym</code> method.
+ *
+ *     Symbol("string")    #=> :string
+ *     Symbol(123456)      #=> :"123456"
+ */
+
+static VALUE
+rb_f_symbol(VALUE obj, VALUE arg)
+{
+    return rb_Symbol(arg);
+}
+
+VALUE
+rb_Symbol(VALUE val)
+{
+    return rb_convert_type(val, T_SYMBOL, "Symbol", "to_sym");
+}
+
+/*
  *  Document-class: Class
  *
  *  Classes in Ruby are first-class objects---each is an instance of
@@ -2920,6 +2943,7 @@ Init_Object(void)
     rb_define_global_function("String", rb_f_string, 1);
     rb_define_global_function("Array", rb_f_array, 1);
     rb_define_global_function("Hash", rb_f_hash, 1);
+    rb_define_global_function("Symbol", rb_f_symbol, 1);
 
     rb_cNilClass = rb_define_class("NilClass", rb_cObject);
     rb_define_method(rb_cNilClass, "to_i", nil_to_i, 0);
diff --git a/test/ruby/test_object.rb b/test/ruby/test_object.rb
index 70dcd04..6c65236 100644
--- a/test/ruby/test_object.rb
+++ b/test/ruby/test_object.rb
@@ -210,6 +210,16 @@ class TestObject < Test::Unit::TestCase
     assert_raise(TypeError) { Hash(o) }
   end
 
+  def test_convert_symbol
+    o = Object.new
+    def o.to_sym; "foo"; end
+    assert_raise(TypeError) { Symbol(o) }
+    def o.to_sym; :foo; end
+    assert_equal(:foo, Symbol(o))
+    def o.respond_to?(*) false; end
+    assert_raise(TypeError) { Symbol(o) }
+  end
+
   def test_to_integer
     o = Object.new
     def o.to_i; nil; end
-- 
1.7.11.1