1 ! Copyright (C) 2008 Doug Coleman.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: alien.c-types kernel math namespaces sequences
4 io.backend io.binary combinators system vocabs.loader
5 summary math.bitwise byte-vectors fry byte-arrays
6 math.ranges math.constants math.functions accessors ;
9 SYMBOL: system-random-generator
10 SYMBOL: secure-random-generator
11 SYMBOL: random-generator
13 GENERIC: seed-random ( tuple seed -- )
14 GENERIC: random-32* ( tuple -- r )
15 GENERIC: random-bytes* ( n tuple -- byte-array )
17 M: object random-bytes* ( n tuple -- byte-array )
18 [ [ <byte-vector> ] keep 4 /mod ] dip
19 [ pick '[ _ random-32* 4 >le _ push-all ] times ]
22 [ 2drop ] [ random-32* 4 >le swap head over push-all ] if
25 M: object random-32* ( tuple -- r ) 4 random-bytes* le> ;
27 ERROR: no-random-number-generator ;
29 M: no-random-number-generator summary
30 drop "Random number generator is not defined." ;
32 M: f random-bytes* ( n obj -- * ) no-random-number-generator ;
34 M: f random-32* ( obj -- * ) no-random-number-generator ;
36 : random-bytes ( n -- byte-array )
37 random-generator get random-bytes* ;
41 : random-integer ( n -- n' )
43 [ random-bytes >byte-array byte-array>bignum ]
44 [ 3 shift 2^ ] bi / * >integer ;
48 : random-bits ( numbits -- r ) 2^ random-integer ;
50 : random-bits* ( numbits -- n )
51 1 - [ random-bits ] keep set-bit ;
53 : random ( seq -- elt )
55 [ length random-integer ] keep nth
58 : randomize ( seq -- seq )
59 dup length [ dup 1 > ]
60 [ [ iota random ] [ 1 - ] bi [ pick exchange ] keep ]
63 : delete-random ( seq -- elt )
64 [ length random-integer ] keep [ nth ] 2keep delete-nth ;
66 : with-random ( tuple quot -- )
67 random-generator swap with-variable ; inline
69 : with-system-random ( quot -- )
70 system-random-generator get swap with-random ; inline
72 : with-secure-random ( quot -- )
73 secure-random-generator get swap with-random ; inline
75 : uniform-random-float ( min max -- n )
76 4 random-bytes underlying>> *uint >float
77 4 random-bytes underlying>> *uint >float
79 [ over - 2.0 -64 ^ * ] dip
82 : normal-random-float ( mean sigma -- n )
83 0.0 1.0 uniform-random-float
84 0.0 1.0 uniform-random-float
86 [ 1.0 swap - log -2.0 * sqrt ]
90 { [ os windows? ] [ "random.windows" require ] }
91 { [ os unix? ] [ "random.unix" require ] }
94 "random.mersenne-twister" require