assocs.extras: adding if-assoc-empty.

2012-10-04 04:08:44 -07:00 · 2012-10-04 04:08:44 -07:00 · 19ac40f0d9
parent fc5f9451e8
commit 19ac40f0d9
1 changed files with 2 additions and 1 deletions
--- a/extra/assocs/extras/extras.factor
+++ b/extra/assocs/extras/extras.factor
@ -37,4 +37,5 @@ IN: assocs.extras

 : sum-values ( assoc -- n ) 0 [ + ] reduce-values ; inline

-
+: if-assoc-empty ( ..a assoc quot1: ( ..a -- ..b ) quot2: ( ..a assoc -- ..b ) -- ..b )
+    [ dup assoc-empty? ] [ [ drop ] prepose ] [ ] tri* if ; inline