sequences.extras: adding map-sift and map-harvest.

diff --git a/extra/sequences/extras/extras.factor b/extra/sequences/extras/extras.factor
index 6755e94254bf004542a76e4c155689c7854907d7..26cd3dad2c5d235ecb0255687c737339abfb6331 100644 (file)
--- a/extra/sequences/extras/extras.factor
+++ b/extra/sequences/extras/extras.factor
@@ -133,3 +133,9 @@ IN: sequences.extras
 
 : map-filter ( ... seq quot: ( ... elt -- ... newelt ) quot: ( ... newelt -- ... ? ) -- ... subseq )
     pick map-filter-as ; inline
+
+: map-sift ( ... seq quot: ( ... elt -- ... newelt ) -- ... newseq )
+    [ ] map-filter ; inline
+
+: map-harvest ( ... seq quot: ( ... elt -- ... newelt ) -- ... newseq )
+    [ empty? not ] map-filter ; inline