From 3e8c3897abe511678b1c8455b5441f95151089c9 Mon Sep 17 00:00:00 2001
From: knu <knu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Tue, 26 Aug 2008 05:45:18 +0000
Subject: [PATCH] * enumerator.c: Activate Enumerator#with_object and add  
 Enumerable#each_with_object.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@18864 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog    |  5 +++++
 doc/NEWS     |  2 ++
 enumerator.c | 41 +++++++++++++++++++++++++++++++++++------
 3 files changed, 42 insertions(+), 6 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 4479dc7139..2602d73fed 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Aug 26 14:43:10 2008  Akinori MUSHA  <knu@iDaemons.org>
+
+	* enumerator.c: Activate Enumerator#with_object and add
+	  Enumerable#each_with_object.
+
 Tue Aug 26 14:38:32 2008  Akinori MUSHA  <knu@iDaemons.org>
 
 	* enumerator.c (enumerator_initialize),
diff --git a/doc/NEWS b/doc/NEWS
index ca5d511ebe..77ecf74178 100644
--- a/doc/NEWS
+++ b/doc/NEWS
@@ -111,6 +111,8 @@ Compatible
     * Enumerable and Enumerator
           o Enumerable#map,collect_all called without a block returns
             an enumerator.
+          o Enumerable#each_with_object [experimental]
+          o Enumerator#with_object [experimental]
           o Enumerator.new { ... } [experimental]
     * Regexp#match, String#match
           o Regexp#match, String#match
diff --git a/enumerator.c b/enumerator.c
index 240641d909..f7fbd7218c 100644
--- a/enumerator.c
+++ b/enumerator.c
@@ -216,6 +216,37 @@ enum_each_cons(VALUE obj, VALUE n)
     return Qnil;
 }
 
+static VALUE
+each_with_object_i(VALUE val, VALUE 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(VALUE obj, VALUE 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 klass)
 {
@@ -412,7 +443,7 @@ enumerator_with_object_i(VALUE val, VALUE memo)
  *    e.with_object(obj)
  *
  *  Iterates the given block for each element with an arbitrary
- *  object given, and returns memo object.
+ *  object given, and returns the initially given object.
  *
  *  If no block is given, returns an enumerator.
  *
@@ -424,7 +455,7 @@ enumerator_with_object(VALUE obj, VALUE memo)
     int argc = 0;
     VALUE *argv = 0;
 
-    RETURN_ENUMERATOR(obj, 0, 0);
+    RETURN_ENUMERATOR(obj, 1, &memo);
     e = enumerator_ptr(obj);
     if (e->args) {
 	argc = RARRAY_LEN(e->args);
@@ -734,6 +765,7 @@ Init_Enumerator(void)
 
     rb_define_method(rb_mEnumerable, "each_slice", enum_each_slice, 1);
     rb_define_method(rb_mEnumerable, "each_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);
@@ -743,12 +775,9 @@ Init_Enumerator(void)
     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);
-#if 0
     rb_define_method(rb_cEnumerator, "with_object", enumerator_with_object, 1);
-#else
-    (void)enumerator_with_object;
-#endif
     rb_define_method(rb_cEnumerator, "next", enumerator_next, 0);
     rb_define_method(rb_cEnumerator, "rewind", enumerator_rewind, 0);