assocs.extras: adding assoc-harvest and assoc-sift.

diff --git a/extra/assocs/extras/extras.factor b/extra/assocs/extras/extras.factor
new file mode 100644 (file)
index 0000000..8fd267c
--- /dev/null
+++ b/extra/assocs/extras/extras.factor
@@ -0,0 +1,13 @@
+! Copyright (C) 2012 John Benediktsson
+! See http://factorcode.org/license.txt for BSD license
+
+USING: assocs kernel sequences ;
+
+IN: assocs.extras
+
+: assoc-harvest ( assoc -- assoc' )
+    [ nip empty? not ] assoc-filter ; inline
+
+: assoc-sift ( assoc -- assoc' )
+    [ nip ] assoc-filter ; inline
+