* enumerator.c (lazy_flat_map_func): convert the block value to

  Array if it doesn't respond to each.  [ruby-core:43334]
  [Bug #6155]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@35092 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 59 insertions, 2 deletions

diff --git a/ChangeLog b/ChangeLog
index a95c72a73a..2101890a94 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,12 @@
+Mon Mar 19 17:18:51 2012  Shugo Maeda  <shugo@ruby-lang.org>
+
+	* enumerator.c (lazy_flat_map_func): convert the block value to
+	  Array if it doesn't respond to each.  [ruby-core:43334]
+	  [Bug #6155]
+
 Mon Mar 19 16:34:14 2012  Shugo Maeda  <shugo@ruby-lang.org>
 
-	* enum.c (zip_i):  variadic argument needs explicit cast on the
+	* enum.c (zip_i): variadic argument needs explicit cast on the
 	  platforms where VALUE is longer than int.
 
 Mon Mar 19 15:36:41 2012  Shugo Maeda  <shugo@ruby-lang.org>
diff --git a/enumerator.c b/enumerator.c
index 9484f495cc..865730912f 100644
--- a/enumerator.c
+++ b/enumerator.c
@@ -1300,6 +1300,32 @@ lazy_flat_map_i(VALUE i, VALUE yielder, int argc, VALUE *argv)
 }
 
 static VALUE
+lazy_flat_map_each(VALUE obj)
+{
+    NODE *memo = RNODE(obj);
+    rb_block_call(memo->u1.value, id_each, 0, 0, lazy_flat_map_i,
+		  memo->u2.value);
+    return Qnil;
+}
+
+static VALUE
+lazy_flat_map_to_ary(VALUE obj)
+{
+    NODE *memo = RNODE(obj);
+    VALUE ary = rb_check_array_type(memo->u1.value);
+    if (NIL_P(ary)) {
+	rb_funcall(memo->u2.value, id_yield, 1, memo->u1.value);
+    }
+    else {
+	long i;
+	for (i = 0; i < RARRAY_LEN(ary); i++) {
+	    rb_funcall(memo->u2.value, id_yield, 1, RARRAY_PTR(ary)[i]);
+	}
+    }
+    return Qnil;
+}
+
+static VALUE
 lazy_flat_map_func(VALUE val, VALUE m, int argc, VALUE *argv)
 {
     VALUE result = rb_yield_values2(argc - 1, &argv[1]);
@@ -1310,7 +1336,11 @@ lazy_flat_map_func(VALUE val, VALUE m, int argc, VALUE *argv)
 	}
     }
     else {
-	rb_block_call(result, id_each, 0, 0, lazy_flat_map_i, argv[0]);
+	NODE *memo;
+	memo = NEW_MEMO(result, argv[0], 0);
+	rb_rescue2(lazy_flat_map_each, (VALUE) memo,
+		   lazy_flat_map_to_ary, (VALUE) memo,
+		   rb_eNoMethodError, (VALUE)0);
     }
     return Qnil;
 }
diff --git a/test/ruby/test_lazy_enumerator.rb b/test/ruby/test_lazy_enumerator.rb
index 0f2fa2bc41..5260043d43 100644
--- a/test/ruby/test_lazy_enumerator.rb
+++ b/test/ruby/test_lazy_enumerator.rb
@@ -110,6 +110,27 @@ class TestLazyEnumerator < Test::Unit::TestCase
     assert_equal(1, a.current)
   end
 
+  def test_flat_map_to_ary
+    to_ary = Class.new {
+      def initialize(value)
+        @value = value
+      end
+
+      def to_ary
+        [:to_ary, @value]
+      end
+    }
+    assert_equal([:to_ary, 1, :to_ary, 2, :to_ary, 3],
+                 [1, 2, 3].flat_map {|x| to_ary.new(x)})
+    assert_equal([:to_ary, 1, :to_ary, 2, :to_ary, 3],
+                 [1, 2, 3].lazy.flat_map {|x| to_ary.new(x)}.force)
+  end
+
+  def test_flat_map_non_array
+    assert_equal(["1", "2", "3"], [1, 2, 3].flat_map {|x| x.to_s})
+    assert_equal(["1", "2", "3"], [1, 2, 3].lazy.flat_map {|x| x.to_s}.force)
+  end
+
   def test_reject
     a = Step.new(1..6)
     assert_equal(4, a.reject {|x| x < 4}.first)