From: Doug Coleman <doug.coleman@gmail.com>
Date: Thu, 7 Apr 2016 20:22:18 +0000 (-0700)
Subject: sequences.extras: Allow from to be f in ?<slice>
X-Git-Tag: unmaintained~1204
X-Git-Url: https://gitweb.factorcode.org/gitweb.cgi?p=factor.git;a=commitdiff_plain;h=a15465a9c29624413402ea00fdc5acd954b92b60

sequences.extras: Allow from to be f in ?<slice>
---

diff --git a/extra/sequences/extras/extras.factor b/extra/sequences/extras/extras.factor
index 1d9148dd27..b057f6e4c2 100644
--- a/extra/sequences/extras/extras.factor
+++ b/extra/sequences/extras/extras.factor
@@ -149,8 +149,10 @@ PRIVATE>
 : cut-slice* ( seq n -- before after )
     [ head-slice* ] [ tail-slice* ] 2bi ;
 
-: ?<slice> ( from to/f sequence -- slice )
-    over [ nip [ length ] [ ] bi ] unless <slice> ; inline
+: ?<slice> ( from/f to/f sequence -- slice )
+    [ [ 0 ] unless* ] 2dip
+    over [ nip [ length ] [ ] bi ] unless
+    <slice> ; inline
 
 : sequence>slice ( sequence -- slice )
     [ drop 0 ] [ length ] [ ] tri <slice> ; inline