sequences: define ?first and ?second.

[factor.git] / extra / sequences / modified / modified.factor

diff --git a/extra/sequences/modified/modified.factor b/extra/sequences/modified/modified.factor
index 73fcc651bda4ef2de50b06751743de0de069c421..944242bac807405ee9516cd328a9333323d20129 100644 (file)
--- a/extra/sequences/modified/modified.factor
+++ b/extra/sequences/modified/modified.factor
@@ -72,7 +72,7 @@ M: summed set-length ( n seq -- )
     seqs>> [ set-length ] with each ;
 
 M: summed virtual-exemplar ( summed -- seq )
-    seqs>> [ f ] [ first ] if-empty ;
+    seqs>> ?first ;
 
 : <2summed> ( seq seq -- summed-seq ) 2array <summed> ;
 : <3summed> ( seq seq seq -- summed-seq ) 3array <summed> ;