From a15465a9c29624413402ea00fdc5acd954b92b60 Mon Sep 17 00:00:00 2001
From: Doug Coleman <doug.coleman@gmail.com>
Date: Thu, 7 Apr 2016 13:22:18 -0700
Subject: [PATCH] sequences.extras: Allow from to be f in ?<slice>

---
 extra/sequences/extras/extras.factor | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

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
-- 
2.34.1