diff --git a/ChangeLog b/ChangeLog
index 2ae99763e7..a01cd93ae3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Fri Sep 21 02:11:22 2007  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* re.c (rb_reg_match_m): evaluate a block if match.  it would make
+	  condition statement much shorter, if no else clause is needed.
+
+	* string.c (rb_str_match_m): ditto.
+
 Fri Sep 21 02:02:34 2007  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* hash.c (hash_equal): should call rb_eql when argument eql is set.
diff --git a/re.c b/re.c
index 32c8942ef2..871ee60738 100644
--- a/re.c
+++ b/re.c
@@ -1797,6 +1797,19 @@ rb_reg_match2(VALUE re)
  *
  *     /(.)(.)(.)/.match("abc")[2]   #=> "b"
  *     /(.)(.)/.match("abc", 1)[2]   #=> "c"
+ *     
+ *  If a block is given, invoke the block with MatchData if match succeed, so
+ *  that you can write
+ *     
+ *     pat.match(str) {|m| ...}
+ *     
+ *  instead of
+ *      
+ *     if m = pat.match(str)
+ *       ...
+ *     end
+ *      
+ *  The retuen value is a value from block exection in this case.
  */
 
 static VALUE
@@ -1819,6 +1832,9 @@ rb_reg_match_m(int argc, VALUE *argv, VALUE re)
     }
     result = rb_backref_get();
     rb_match_busy(result);
+    if (!NIL_P(result) && rb_block_given_p()) {
+	return rb_yield(result);
+    }
     return result;
 }
 
diff --git a/string.c b/string.c
index 0a50f174fe..1cad0f8bf5 100644
--- a/string.c
+++ b/string.c
@@ -1547,17 +1547,34 @@ static VALUE get_pat(VALUE, int);
  *     'hello'.match('(.)\1')[0]   #=> "ll"
  *     'hello'.match(/(.)\1/)[0]   #=> "ll"
  *     'hello'.match('xx')         #=> nil
+ *     
+ *  If a block is given, invoke the block with MatchData if match succeed, so
+ *  that you can write
+ *     
+ *     str.match(pat) {|m| ...}
+ *     
+ *  instead of
+ *      
+ *     if m = str.match(pat)
+ *       ...
+ *     end
+ *      
+ *  The retuen value is a value from block exection in this case.
  */
 
 static VALUE
 rb_str_match_m(int argc, VALUE *argv, VALUE str)
 {
-    VALUE re;
+    VALUE re, result;
     if (argc < 1)
 	rb_raise(rb_eArgError, "wrong number of arguments (%d for 1)", argc);
     re = argv[0];
     argv[0] = str;
-    return rb_funcall2(get_pat(re, 0), rb_intern("match"), argc, argv);
+    result = rb_funcall2(get_pat(re, 0), rb_intern("match"), argc, argv);
+    if (!NIL_P(result) && rb_block_given_p()) {
+	return rb_yield(result);
+    }
+    return result;
 }
 
 static int