* enumerator.c (ary2sv): add dup argument.

(enumerator_next): call ary2sv with dup=0.
  (enumerator_peek): call ary2sv with dup=1 to return duplicated array.
  (enumerator_peek_values_m): new function to return duplicated array.
  (Init_Enumerator): use enumerator_peek_values_m as
  Enumerator#peek_value.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@24619 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,12 @@
+Sat Aug 22 00:48:08 2009  Tanaka Akira  <akr@fsij.org>
+
+	* enumerator.c (ary2sv): add dup argument.
+	  (enumerator_next): call ary2sv with dup=0.
+	  (enumerator_peek): call ary2sv with dup=1 to return duplicated array.
+	  (enumerator_peek_values_m): new function to return duplicated array.
+	  (Init_Enumerator): use enumerator_peek_values_m as
+	  Enumerator#peek_value.
+
 Sat Aug 22 00:03:19 2009  Yusuke Endoh  <mame@tsg.ne.jp>
 
 	* thread.c (rb_check_deadlock): decrease number of sleepers before

enumerator.c

@@ -680,7 +680,7 @@ enumerator_next_values(VALUE obj)
 }
 
 static VALUE
-ary2sv(VALUE args)
+ary2sv(VALUE args, int dup)
 {
     if (TYPE(args) != T_ARRAY)
         return args;
@@ -693,6 +693,8 @@ ary2sv(VALUE args)
         return RARRAY_PTR(args)[0];
 
       default:
+        if (dup)
+            return rb_ary_dup(args);
         return args;
     }
 }
@@ -715,7 +717,18 @@ static VALUE
 enumerator_next(VALUE obj)
 {
     VALUE vs = enumerator_next_values(obj);
-    return ary2sv(vs);
+    return ary2sv(vs, 0);
+}
+
+static VALUE
+enumerator_peek_values(VALUE obj)
+{
+    struct enumerator *e = enumerator_ptr(obj);
+
+    if (e->lookahead == Qundef) {
+        e->lookahead = get_next_values(obj, e);
+    }
+    return e->lookahead;
 }
 
 /*
@@ -744,14 +757,9 @@ enumerator_next(VALUE obj)
  */
 
 static VALUE
-enumerator_peek_values(VALUE obj)
+enumerator_peek_values_m(VALUE obj)
 {
-    struct enumerator *e = enumerator_ptr(obj);
-
-    if (e->lookahead == Qundef) {
-        e->lookahead = get_next_values(obj, e);
-    }
-    return e->lookahead;
+    return rb_ary_dup(enumerator_peek_values(obj));
 }
 
 /*
@@ -768,7 +776,7 @@ static VALUE
 enumerator_peek(VALUE obj)
 {
     VALUE vs = enumerator_peek_values(obj);
-    return ary2sv(vs);
+    return ary2sv(vs, 1);
 }
 
 /*
@@ -1153,7 +1161,7 @@ Init_Enumerator(void)
     rb_define_method(rb_cEnumerator, "with_index", enumerator_with_index, -1);
     rb_define_method(rb_cEnumerator, "with_object", enumerator_with_object, 1);
     rb_define_method(rb_cEnumerator, "next_values", enumerator_next_values, 0);
-    rb_define_method(rb_cEnumerator, "peek_values", enumerator_peek_values, 0);
+    rb_define_method(rb_cEnumerator, "peek_values", enumerator_peek_values_m, 0);
     rb_define_method(rb_cEnumerator, "next", enumerator_next, 0);
     rb_define_method(rb_cEnumerator, "peek", enumerator_peek, 0);
     rb_define_method(rb_cEnumerator, "feed", enumerator_feed, 1);

test/ruby/test_enumerator.rb

@@ -141,6 +141,28 @@ class TestEnumerator < Test::Unit::TestCase
     assert_raise(StopIteration) { e.peek }
   end
 
+  def test_peek_modify
+    o = Object.new
+    def o.each
+      yield 1,2
+    end
+    e = o.to_enum
+    a = e.peek
+    a << 3
+    assert_equal([1,2], e.peek)
+  end
+
+  def test_peek_values_modify
+    o = Object.new
+    def o.each
+      yield 1,2
+    end
+    e = o.to_enum
+    a = e.peek_values
+    a << 3
+    assert_equal([1,2], e.peek)
+  end
+
   def test_next_after_stopiteration
     a = [1]
     e = a.each