sequences: adding ?last for symmetry.

[factor.git] / core / sequences / sequences.factor

diff --git a/core/sequences/sequences.factor b/core/sequences/sequences.factor
index 0971982e53c20b5ed6ab8970789b9cf9776093e4..32cbce114f04dfbe4c3026f3934be7f7044fb382 100644 (file)
--- a/core/sequences/sequences.factor
+++ b/core/sequences/sequences.factor
@@ -177,6 +177,7 @@ PRIVATE>
 
 : ?first ( seq -- elt/f ) 0 swap ?nth ; inline
 : ?second ( seq -- elt/f ) 1 swap ?nth ; inline
+: ?last ( seq -- elt/f ) [ length 1 - ] [ ?nth ] bi ; inline
 
 MIXIN: virtual-sequence
 GENERIC: virtual-exemplar ( seq -- seq' )