* enum.c (enum_cycle): new method to cycle enumerable forever.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@12890 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,7 @@
+Tue Aug  7 01:15:24 2007  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* enum.c (enum_cycle): new method to cycle enumerable forever.
+
 Tue Aug  7 00:05:38 2007  Keiju Ishitsuka  <keiju@ruby-lang.org>
 
 	* irb/ruby-lex.rb: support for '\c'. [ruby-talk:263508]

array.c

@@ -2951,6 +2951,31 @@ rb_ary_choice(VALUE ary)
 }
 
 
+/*
+ *  call-seq:
+ *     ary.cycle {|obj| block }
+ *  
+ *  Calls <i>block</i> repeatedly forever.
+ *     
+ *     a = ["a", "b", "c"]
+ *     a.each {|x| puts x }  # print, a, b, c, a, b, c,.. forever.
+ *     
+ */
+
+static VALUE
+rb_ary_cycle(VALUE ary)
+{
+    long i;
+
+    RETURN_ENUMERATOR(ary, 0, 0);
+    for (;;) {
+	for (i=0; i<RARRAY_LEN(ary); i++) {
+	    rb_yield(RARRAY_PTR(ary)[i]);
+	}
+    }
+    return Qnil;
+}
+
 /* Arrays are ordered, integer-indexed collections of any object. 
  * Array indexing starts at 0, as in C or Java.  A negative index is 
  * assumed to be relative to the end of the array---that is, an index of -1 
@@ -3048,6 +3073,7 @@ Init_Array(void)
     rb_define_method(rb_cArray, "shuffle!", rb_ary_shuffle_bang, 0);
     rb_define_method(rb_cArray, "shuffle", rb_ary_shuffle, 0);
     rb_define_method(rb_cArray, "choice", rb_ary_choice, 0);
+    rb_define_method(rb_cArray, "cycle", rb_ary_cycle, 0);
 
     id_cmp = rb_intern("<=>");
 }

enum.c

@@ -1526,6 +1526,44 @@ enum_drop(int argc, VALUE *argv, VALUE obj)
     return args[0];
 }
 
+
+static VALUE
+cycle_i(VALUE i, VALUE ary)
+{
+    rb_ary_push(ary, i);
+    rb_yield(i);
+    return Qnil;
+}
+
+/*
+ *  call-seq:
+ *     enum.cycle {|obj| block }
+ *  
+ *  Calls <i>block</i> for each element of enumerable repeatedly
+ *  forever.  Enumerable#cycle saves elements in an internal array.
+ *     
+ *     a = ["a", "b", "c"]
+ *     a.each {|x| puts x }  # print, a, b, c, a, b, c,.. forever.
+ *     
+ */
+
+static VALUE
+enum_cycle(VALUE obj)
+{
+    VALUE ary;
+    long i;
+
+    RETURN_ENUMERATOR(obj, 0, 0);
+    ary = rb_ary_new();
+    rb_block_call(obj, id_each, 0, 0, cycle_i, ary);
+    for (;;) {
+	for (i=0; i<RARRAY_LEN(ary); i++) {
+	    rb_yield(RARRAY_PTR(ary)[i]);
+	}
+    }
+    return Qnil;
+}
+
 /*
  *  The <code>Enumerable</code> mixin provides collection classes with
  *  several traversal and searching methods, and with the ability to
@@ -1578,6 +1616,7 @@ Init_Enumerable(void)
     rb_define_method(rb_mEnumerable, "zip", enum_zip, -1);
     rb_define_method(rb_mEnumerable, "take", enum_take, -1);
     rb_define_method(rb_mEnumerable, "drop", enum_drop, -1);
+    rb_define_method(rb_mEnumerable, "cycle", enum_cycle, 0);
 
     id_eqq  = rb_intern("===");
     id_each = rb_intern("each");

version.h

@@ -1,7 +1,7 @@
 #define RUBY_VERSION "1.9.0"
-#define RUBY_RELEASE_DATE "2007-08-06"
+#define RUBY_RELEASE_DATE "2007-08-07"
 #define RUBY_VERSION_CODE 190
-#define RUBY_RELEASE_CODE 20070806
+#define RUBY_RELEASE_CODE 20070807
 #define RUBY_PATCHLEVEL 0
 
 #define RUBY_VERSION_MAJOR 1
@@ -9,7 +9,7 @@
 #define RUBY_VERSION_TEENY 0
 #define RUBY_RELEASE_YEAR 2007
 #define RUBY_RELEASE_MONTH 8
-#define RUBY_RELEASE_DAY 6
+#define RUBY_RELEASE_DAY 7
 
 #ifdef RUBY_EXTERN
 RUBY_EXTERN const char ruby_version[];