sequences: implement sum on repetitions.

2014-02-09 08:05:26 -08:00 · 2014-02-09 08:05:26 -08:00 · ab4a058b2c
parent d9961f5f4a
commit ab4a058b2c
1 changed files with 1 additions and 0 deletions
--- a/core/sequences/sequences.factor
+++ b/core/sequences/sequences.factor
@ -1017,6 +1017,7 @@ PRIVATE>
 GENERIC: sum ( seq -- n )
 M: object sum 0 [ + ] binary-reduce ; inline
 M: iota-tuple sum length dup 1 - * 2/ ; inline
+M: repetition sum [ elt>> ] [ len>> ] bi * ; inline

 : product ( seq -- n ) 1 [ * ] binary-reduce ;