sequences.extras: Add map-infimum and map-supremum

Resolves #522

diff --git a/extra/sequences/extras/extras.factor b/extra/sequences/extras/extras.factor
index 09e7a9acada5ae7731cc2e8b2f4bcdfcf5b5b9a7..1704ca20558d05777c01094972982918fd0e059b 100644 (file)
--- a/extra/sequences/extras/extras.factor
+++ b/extra/sequences/extras/extras.factor
@@ -642,6 +642,12 @@ PRIVATE>
         [ ] [ 2dup and [ min ] [ dupd ? ] if ] map-reduce
     ] if-empty ;
 
+: map-infimum ( seq quot: ( ... elt -- ... elt' ) -- elt' )
+    [ min ] map-reduce ;
+
+: map-supremum ( seq quot: ( ... elt -- ... elt' ) -- elt' )
+    [ max ] map-reduce ;
+
 : change-last ( seq quot -- )
     [ index-of-last ] [ change-nth ] bi* ; inline