Add rb_enumeratorize_with_size_kw and related macros

Currently, there is not a way to create a sized enumerator in C
with a different set of arguments than provided by Ruby, and
correctly handle keyword arguments.  This function allows that.

The need for this is fairly uncommon, but it occurs at least in
Enumerator.produce, which takes arugments from Ruby but calls
rb_enumeratorize_with_size with a different set of arguments.

1 files changed, 8 insertions, 0 deletions

diff --git a/test/ruby/test_enumerator.rb b/test/ruby/test_enumerator.rb
index 1e306c33a2..65adb5a438 100644
--- a/test/ruby/test_enumerator.rb
+++ b/test/ruby/test_enumerator.rb
@@ -831,6 +831,14 @@ class TestEnumerator < Test::Unit::TestCase
     assert_equal [1, 2, 3], enum.take(3)
     assert_equal [1, 2], passed_args
 
+    # With initial keyword arguments
+    passed_args = []
+    enum = Enumerator.produce(a: 1, b: 1) { |obj| passed_args << obj; obj.shift if obj.respond_to?(:shift)}
+    assert_instance_of(Enumerator, enum)
+    assert_equal Float::INFINITY, enum.size
+    assert_equal [{b: 1}, [1], :a, nil], enum.take(4)
+    assert_equal [{b: 1}, [1], :a], passed_args
+
     # Raising StopIteration
     words = "The quick brown fox jumps over the lazy dog.".scan(/\w+/)
     enum = Enumerator.produce { words.shift or raise StopIteration }