assocs.extras: adding a "zip-as" that is faster than "zip >hashtable".

[factor.git] / extra / assocs / extras / extras.factor

diff --git a/extra/assocs/extras/extras.factor b/extra/assocs/extras/extras.factor
index 18b84780421a86e47be588e634c266ab87aa10e3..d788ff6ce5bfdd7920db463bc17b584e3177d959 100644 (file)
--- a/extra/assocs/extras/extras.factor
+++ b/extra/assocs/extras/extras.factor
@@ -1,7 +1,7 @@
 ! Copyright (C) 2012 John Benediktsson
 ! See http://factorcode.org/license.txt for BSD license
 
-USING: assocs kernel sequences ;
+USING: arrays assocs assocs.private kernel sequences ;
 
 IN: assocs.extras
 
@@ -13,3 +13,11 @@ IN: assocs.extras
 
 : deep-at ( assoc seq -- value/f )
     [ swap at ] each ;
+
+: zip-as ( keys values exemplar -- assocs )
+    dup sequence? [
+        [ 2array ] swap 2map-as
+    ] [
+        [ dup length ] dip new-assoc
+        [ [ set-at ] with-assoc 2each ] keep
+    ] if ;