From faed90d814d6739cc55e6f0103fdc06fc1c5de0a Mon Sep 17 00:00:00 2001
From: marcandre <marcandre@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Tue, 6 Nov 2012 17:15:00 +0000
Subject: [PATCH] * range.c: Support for range.step.size   [Feature #6636]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@37517 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 range.c                      | 25 ++++++++++++++++++++++++-
 test/ruby/test_enumerator.rb |  6 ++++++
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/range.c b/range.c
index b449e97758..d83e1d2eb1 100644
--- a/range.c
+++ b/range.c
@@ -315,6 +315,29 @@ discrete_object_p(VALUE obj)
     return rb_respond_to(obj, id_succ);
 }
 
+static VALUE
+range_step_size(VALUE range, VALUE args)
+{
+    VALUE b = RANGE_BEG(range), e = RANGE_END(range);
+    VALUE step = INT2FIX(1);
+    if (args) {
+	step = RARRAY_PTR(args)[0];
+	if (!rb_obj_is_kind_of(step, rb_cNumeric)) {
+	    step = rb_to_int(step);
+	}
+    }
+    if (rb_funcall(step, '<', 1, INT2FIX(0))) {
+	rb_raise(rb_eArgError, "step can't be negative");
+    }
+    else if (!rb_funcall(step, '>', 1, INT2FIX(0))) {
+	rb_raise(rb_eArgError, "step can't be 0");
+    }
+
+    if (rb_obj_is_kind_of(b, rb_cNumeric) && rb_obj_is_kind_of(e, rb_cNumeric)) {
+	return num_interval_step_size(b, e, step, EXCL(range));
+    }
+    return Qnil;
+}
 
 /*
  *  call-seq:
@@ -355,7 +378,7 @@ range_step(int argc, VALUE *argv, VALUE range)
 {
     VALUE b, e, step, tmp;
 
-    RETURN_ENUMERATOR(range, argc, argv);
+    RETURN_SIZED_ENUMERATOR(range, argc, argv, range_step_size);
 
     b = RANGE_BEG(range);
     e = RANGE_END(range);
diff --git a/test/ruby/test_enumerator.rb b/test/ruby/test_enumerator.rb
index 8203aabc56..3ce471bb24 100644
--- a/test/ruby/test_enumerator.rb
+++ b/test/ruby/test_enumerator.rb
@@ -536,6 +536,12 @@ class TestEnumerator < Test::Unit::TestCase
     assert_equal 1, 42.step(Float::INFINITY, Float::INFINITY).size
     assert_equal 14, 0.1.step(4.2, 0.3).size
     assert_equal Float::INFINITY, 42.step(Float::INFINITY, 2).size
+
+    assert_equal 10, (1..10).step.size
+    assert_equal 4, (1..10).step(3).size
+    assert_equal 3, (1...10).step(3).size
+    assert_equal Float::INFINITY, (42..Float::INFINITY).step(2).size
+    assert_raise(ArgumentError){ (1..10).step(-2).size }
   end
 end