sequences: change implementation of interleave

2009-06-14 18:22:31 -05:00 · 2009-06-14 18:22:31 -05:00 · 75276855ae
parent dd61b59937
commit 75276855ae
1 changed files with 5 additions and 3 deletions
--- a/core/sequences/sequences.factor
+++ b/core/sequences/sequences.factor
@ -508,9 +508,11 @@ PRIVATE>
    (each-index) each-integer ; inline

 : interleave ( seq between quot -- )
-    swap [ drop ] [ [ 2dip call ] 2curry ] 2bi
-    [ [ 0 = ] 2dip if ] 2curry
-    each-index ; inline
+    pick empty? [ 3drop ] [
+        [ [ drop first-unsafe ] dip call ]
+        [ [ rest-slice ] 2dip [ [ call ] bi@ ] 2curry each ]
+        3bi
+    ] if ; inline

 : map-index ( seq quot -- newseq )
    [ dup length iota ] dip 2map ; inline