* enumerator.c (enum_each_with_object): Add

  Enumerable#each_with_object and Enumerator#with_object.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8@20627 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 87 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 9eb2302b46..88e9e4236b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Dec 11 19:08:38 2008  Akinori MUSHA  <knu@iDaemons.org>
+
+	* enumerator.c (enum_each_with_object): Add
+	  Enumerable#each_with_object and Enumerator#with_object.
+
 Wed Dec 10 21:35:12 2008  Kouhei Sutou  <kou@cozmixng.org>
 
 	* lib/rss/maker.rb (RSS::Maker.[]): add.
diff --git a/NEWS b/NEWS
index cd721ed5c6..64623b3f4d 100644
--- a/NEWS
+++ b/NEWS
@@ -26,6 +26,14 @@ with all sufficient information, see the ChangeLog file.
 
     New method with which replaces #choice.
 
+  * Enumerable#each_with_object
+
+    New method.
+
+  * Enumerator#with_object
+
+    New method.
+
   * Hash#default_proc=
 
     New method.
diff --git a/enumerator.c b/enumerator.c
index 896863a78a..71362c168c 100644
--- a/enumerator.c
+++ b/enumerator.c
@@ -208,6 +208,39 @@ enum_each_cons(obj, n)
     return Qnil;
 }
 
+static VALUE
+each_with_object_i(val, memo)
+    VALUE val, memo;
+{
+    return rb_yield_values(2, val, memo);
+}
+
+/*
+ *  call-seq:
+ *    each_with_object(obj) {|(*args), memo_obj| ... }
+ *    each_with_object(obj)
+ *
+ *  Iterates the given block for each element with an arbitrary
+ *  object given, and returns the initially given object.
+
+ *  If no block is given, returns an enumerator.
+ *
+ *  e.g.:
+ *      evens = (1..10).each_with_object([]) {|i, a| a << i*2 }
+ *      # => [2, 4, 6, 8, 10, 12, 14, 16, 18, 20]
+ *
+ */
+static VALUE
+enum_each_with_object(obj, memo)
+    VALUE obj, memo;
+{
+    RETURN_ENUMERATOR(obj, 1, &memo);
+
+    rb_block_call(obj, SYM2ID(sym_each), 0, 0, each_with_object_i, memo);
+
+    return memo;
+}
+
 static VALUE enumerator_allocate _((VALUE));
 static VALUE
 enumerator_allocate(klass)
@@ -380,6 +413,44 @@ enumerator_with_index(obj)
 			 enumerator_with_index_i, (VALUE)&memo);
 }
 
+static VALUE
+enumerator_with_object_i(val, memo)
+    VALUE val, memo;
+{
+    return rb_yield_values(2, val, memo);
+}
+
+/*
+ *  call-seq:
+ *    e.with_object(obj) {|(*args), memo_obj| ... }
+ *    e.with_object(obj)
+ *
+ *  Iterates the given block for each element with an arbitrary
+ *  object given, and returns the initially given object.
+ *
+ *  If no block is given, returns an enumerator.
+ *
+ */
+static VALUE
+enumerator_with_object(obj, memo)
+    VALUE obj, memo;
+{
+    struct enumerator *e;
+    int argc = 0;
+    VALUE *argv = 0;
+
+    RETURN_ENUMERATOR(obj, 1, &memo);
+    e = enumerator_ptr(obj);
+    if (e->args) {
+	argc = RARRAY_LEN(e->args);
+	argv = RARRAY_PTR(e->args);
+    }
+    rb_block_call(e->obj, e->meth, argc, argv,
+		  enumerator_with_object_i, memo);
+
+    return memo;
+}
+
 /*
  * call-seq:
  *   e.next   => object
@@ -429,6 +500,7 @@ Init_Enumerator()
     rb_define_method(rb_mEnumerable, "enum_slice", enum_each_slice, 1);
     rb_define_method(rb_mEnumerable, "each_cons", enum_each_cons, 1);
     rb_define_method(rb_mEnumerable, "enum_cons", enum_each_cons, 1);
+    rb_define_method(rb_mEnumerable, "each_with_object", enum_each_with_object, 1);
 
     rb_cEnumerator = rb_define_class("Enumerator", rb_cObject);
     rb_include_module(rb_cEnumerator, rb_mEnumerable);
@@ -438,7 +510,9 @@ Init_Enumerator()
     rb_define_method(rb_cEnumerator, "initialize_copy", enumerator_init_copy, 1);
     rb_define_method(rb_cEnumerator, "each", enumerator_each, 0);
     rb_define_method(rb_cEnumerator, "each_with_index", enumerator_with_index, 0);
+    rb_define_method(rb_cEnumerator, "each_with_object", enumerator_with_object, 1);
     rb_define_method(rb_cEnumerator, "with_index", enumerator_with_index, 0);
+    rb_define_method(rb_cEnumerator, "with_object", enumerator_with_object, 1);
     rb_define_method(rb_cEnumerator, "next", enumerator_next, 0);
     rb_define_method(rb_cEnumerator, "rewind", enumerator_rewind, 0);