sequences.extras: adding index-selector.

2013-05-20 17:43:26 -07:00 · 2013-05-20 17:43:26 -07:00 · 2a846cfff9
parent 3ac3c69ab4
commit 2a846cfff9
1 changed files with 3 additions and 0 deletions
--- a/extra/sequences/extras/extras.factor
+++ b/extra/sequences/extras/extras.factor
@ -95,6 +95,9 @@ PRIVATE>
 : index-selector-for ( quot exemplar -- selector accum )
    [ length ] keep (index-selector-for) ; inline

+: index-selector ( quot -- selector accum )
+    V{ } index-selector-for ; inline
+
 : filter-index-as ( ... seq quot: ( ... elt i -- ... ? ) exemplar -- ... seq' )
    pick length over [ (index-selector-for) [ each-index ] dip ] 2curry dip like ; inline