Adding a randomize word to sequences-lib.

extra/sequences/lib/lib-docs.factor

@@ -18,3 +18,8 @@ HELP: each-withn
 "passed to the quotation given to each-withn for each element in the sequence."
 } 
 { $see-also map-withn } ;
+
+HELP: randomize
+{ $values { "seq" sequence } { "seq'" sequence } }
+{ $description "Shuffle the elements in the sequence randomly, returning the new sequence." } ;
+

extra/sequences/lib/lib.factor

@@ -160,3 +160,16 @@ PRIVATE>
 
 : ?nth* ( n seq -- elt/f ? )
     2dup bounds-check? [ nth-unsafe t ] [ 2drop f f ] if ; flushable
+
+! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+USE: math.ranges
+USE: random 
+: randomize ( seq -- seq' )
+    dup length 1-
+    [ dup 1 > ] [
+        [ [0,b) random ] keep dup 
+        [ rot [ exchange ] keep ] dip 1-
+    ] [ drop ] while ;
+    
+