! See http://factorcode.org/license.txt for BSD license.
USING: alien.c-types kernel math namespaces sequences
io.backend io.binary combinators system vocabs.loader
-summary math.bitwise byte-vectors fry byte-arrays ;
+summary math.bitwise byte-vectors fry byte-arrays
+math.ranges ;
IN: random
SYMBOL: system-random-generator
GENERIC: random-bytes* ( n tuple -- byte-array )
M: object random-bytes* ( n tuple -- byte-array )
- [ [ <byte-vector> ] keep 4 /mod ] dip tuck
+ [ [ <byte-vector> ] keep 4 /mod ] dip
[ pick '[ _ random-32* 4 >le _ push-all ] times ]
[
over zero?
[ 2drop ] [ random-32* 4 >le swap head over push-all ] if
- ] 2bi* ;
+ ] bi-curry bi* ;
M: object random-32* ( tuple -- r ) 4 random-bytes* le> ;
[ length random-integer ] keep nth
] if-empty ;
-: randomize ( seq -- seq' )
- dup length 1 (a,b] [ dup random pick exchange ] each ;
+: randomize ( seq -- seq )
+ dup length [ dup 1 > ]
+ [ [ random ] [ 1- ] bi [ pick exchange ] keep ]
+ while drop ;
: delete-random ( seq -- elt )
[ length random-integer ] keep [ nth ] 2keep delete-nth ;