sequences: make sum-lengths generic.

2014-06-02 08:40:38 -07:00 · 2014-06-02 08:40:38 -07:00 · 0a93877d4b
parent 6e834cd0de
commit 0a93877d4b
1 changed files with 6 additions and 1 deletions
--- a/core/sequences/sequences.factor
+++ b/core/sequences/sequences.factor
@ -819,9 +819,14 @@ PRIVATE>
        [ 0 swap copy-unsafe ] keep reverse!
    ] keep like ;

-: sum-lengths ( seq -- n )
+GENERIC: sum-lengths ( seq -- n )
+
+M: object sum-lengths
    0 [ length + ] reduce ;

+M: repetition sum-lengths
+    [ len>> ] [ elt>> length ] bi * ;
+
 : concat-as ( seq exemplar -- newseq )
    swap [ { } ] [
        [ sum-lengths over new-resizable ] keep