assocs.extras: adding assoc-sift.

diff --git a/extra/assocs/extras/extras.factor b/extra/assocs/extras/extras.factor
index ffdf53845d54b79cedc2de7076253cc5841ce199..257288977af5125f22c5694de32b79684e5d7b2c 100644 (file)
--- a/extra/assocs/extras/extras.factor
+++ b/extra/assocs/extras/extras.factor
@@ -5,6 +5,9 @@ USING: arrays assocs assocs.private kernel math sequences ;
 
 IN: assocs.extras
 
+: assoc-sift ( assoc -- assoc' )
+    [ nip ] assoc-filter ; inline
+
 : assoc-harvest ( assoc -- assoc' )
     [ nip empty? not ] assoc-filter ; inline