math.combinators: Add map-permutation

2012-04-18 14:43:08 -07:00 · 2012-04-18 14:43:08 -07:00 · 229d0e0549
parent 161cd8222c
commit 229d0e0549
1 changed files with 4 additions and 0 deletions
--- a/basis/math/combinatorics/combinatorics.factor
+++ b/basis/math/combinatorics/combinatorics.factor
@ -55,6 +55,10 @@ PRIVATE>
    [ [ length factorial iota ] keep ] dip
    '[ _ permutation @ ] each ; inline

+: map-permutation ( seq quot -- )
+    [ [ length factorial iota ] keep ] dip
+    '[ _ permutation @ ] map ; inline
+
 : reduce-permutations ( seq identity quot -- result )
    swapd each-permutation ; inline