! Copyright (C) 2008 Doug Coleman.
! See http://factorcode.org/license.txt for BSD license.
USING: accessors alien.data arrays assocs byte-arrays
-byte-vectors combinators combinators.short-circuit fry
-hashtables hashtables.private hash-sets hints io.backend
-io.binary kernel locals math math.bitwise math.constants
-math.functions math.order math.ranges namespaces sequences
-sequences.private sets summary system typed vocabs ;
+combinators combinators.short-circuit hash-sets hashtables
+hashtables.private kernel math math.bitwise math.constants
+math.functions math.order namespaces sequences sequences.private
+sets summary system vocabs ;
QUALIFIED-WITH: alien.c-types c
QUALIFIED-WITH: sets sets
IN: random
SYMBOL: secure-random-generator
SYMBOL: random-generator
-GENERIC# seed-random 1 ( tuple seed -- tuple' )
-GENERIC: random-32* ( tuple -- r )
-GENERIC: random-bytes* ( n tuple -- byte-array )
-
-M: object random-bytes* ( n tuple -- byte-array )
- [ [ <byte-vector> ] keep 4 /mod ] dip
- [ pick '[ _ random-32* c:int <ref> _ push-all ] times ]
- [
- over zero?
- [ 2drop ] [ random-32* c:int <ref> swap head append! ] if
- ] bi-curry bi* B{ } like ;
-
-HINTS: M\ object random-bytes* { fixnum object } ;
+GENERIC#: seed-random 1 ( obj seed -- obj )
+GENERIC: random-32* ( obj -- n )
+GENERIC: random-bytes* ( n obj -- byte-array )
+
+M: object random-bytes*
+ [ integer>fixnum-strict [ (byte-array) ] keep ] dip
+ [ over 4 >= ] [
+ [ 4 - ] dip
+ [ random-32* 2over c:int c:set-alien-value ] keep
+ ] while over zero? [ 2drop ] [
+ random-32* c:int <ref> swap head 0 pick copy-unsafe
+ ] if ;
-M: object random-32* ( tuple -- r )
+M: object random-32*
4 swap random-bytes* c:uint deref ;
ERROR: no-random-number-generator ;
M: no-random-number-generator summary
drop "Random number generator is not defined." ;
-M: f random-bytes* ( n obj -- * ) no-random-number-generator ;
+M: f random-bytes* no-random-number-generator ;
-M: f random-32* ( obj -- * ) no-random-number-generator ;
+M: f random-32* no-random-number-generator ;
-: random-32 ( -- n ) random-generator get random-32* ;
+: random-32 ( -- n )
+ random-generator get random-32* ;
-TYPED: random-bytes ( n: fixnum -- byte-array: byte-array )
- random-generator get random-bytes* ; inline
+: random-bytes ( n -- byte-array )
+ random-generator get random-bytes* ;
<PRIVATE
-: #bits ( n -- bits )
+:: (random-bits) ( numbits obj -- n )
+ numbits 32 > [
+ obj random-32* numbits 32 - [ dup 32 > ] [
+ [ 32 shift obj random-32* + ] [ 32 - ] bi*
+ ] while [
+ [ shift ] keep obj random-32* swap bits +
+ ] unless-zero
+ ] [
+ obj random-32* numbits bits
+ ] if ; inline
+
+PRIVATE>
+
+: random-bits ( numbits -- n )
+ random-generator get (random-bits) ;
+
+: random-bits* ( numbits -- n )
+ 1 - [ random-bits ] keep set-bit ;
+
+<PRIVATE
+
+: next-power-of-2-bits ( m -- numbits )
dup 2 <= [ drop 1 ] [ 1 - log2 1 + ] if ; inline
-:: (random-bits) ( n bits obj -- n' )
- obj random-32* 32 bits 32 - [ dup 0 > ] [
+:: random-integer-loop ( m obj -- n )
+ obj random-32* 32 m next-power-of-2-bits 32 - [ dup 0 > ] [
[ 32 shift obj random-32* + ] [ 32 + ] [ 32 - ] tri*
- ] while drop [ n * ] [ neg shift ] bi* ; inline
-
-: ((random-integer)) ( n obj -- n' )
- [ dup #bits ] dip (random-bits) ; inline
+ ] while drop [ m * ] [ neg shift ] bi* ; inline
-GENERIC# (random-integer) 1 ( n obj -- n )
-M: fixnum (random-integer) ( n obj -- n' ) ((random-integer)) ;
-M: bignum (random-integer) ( n obj -- n' ) ((random-integer)) ;
+GENERIC#: (random-integer) 1 ( m obj -- n )
+M: fixnum (random-integer) random-integer-loop ;
+M: bignum (random-integer) random-integer-loop ;
-: random-integer ( n -- n' )
+: random-integer ( m -- n )
random-generator get (random-integer) ;
PRIVATE>
-: random-bits ( numbits -- r )
- [ 2^ ] keep random-generator get (random-bits) ;
-
-: random-bits* ( numbits -- n )
- 1 - [ random-bits ] keep set-bit ;
-
GENERIC: random ( obj -- elt )
-M: integer random [ f ] [ random-integer ] if-zero ;
+M: integer random
+ [ f ] [ random-integer ] if-zero ;
M: sequence random
[ f ] [
M: sets:set random members random ;
-M: hash-set random table>> random first ;
+M: hash-set random
+ dup cardinality [ drop f ] [
+ [ 0 ] [ array>> ] [ random ] tri* 1 + [
+ [ 2dup array-nth tombstone? [ 1 + ] 2dip ] loop
+ ] times [ 1 - ] dip array-nth
+ ] if-zero ;
: randomize-n-last ( seq n -- seq )
[ dup length dup ] dip - 1 max '[ dup _ > ]
: sample ( seq n -- seq' )
2dup [ length ] dip < [ too-many-samples ] when
- [ [ length iota >array ] dip [ randomize-n-last ] keep tail-slice* ]
- [ drop ] 2bi nths ;
+ [ [ length <iota> >array ] dip [ randomize-n-last ] keep tail-slice* ]
+ [ drop ] 2bi nths-unsafe ;
: delete-random ( seq -- elt )
[ length random-integer ] keep
[ nth ] 2keep remove-nth! drop ;
-: with-random ( tuple quot -- )
+: with-random ( obj quot -- )
random-generator swap with-variable ; inline
: with-system-random ( quot -- )
: random-integers ( length n -- sequence )
random-generator get '[ _ _ (random-integer) ] replicate ;
+<PRIVATE
+
: (cos-random-float) ( -- n )
0. 2pi uniform-random-float cos ;
: (log-sqrt-random-float) ( -- n )
random-unit log -2. * sqrt ;
+PRIVATE>
+
: normal-random-float ( mean sigma -- n )
(cos-random-float) (log-sqrt-random-float) * * + ;
: pareto-random-float ( k alpha -- n )
[ random-unit ] dip recip ^ /f ;
+<PRIVATE
+
:: (gamma-random-float>1) ( alpha beta -- n )
! Uses R.C.H. Cheng, "The generation of Gamma
! variables with non-integral shape parameters",
] if x!
] do while x beta * ;
+PRIVATE>
+
: gamma-random-float ( alpha beta -- n )
{
{ [ over 1 > ] [ (gamma-random-float>1) ] }
rnd (random-unit) 0.5 > [ + ] [ - ] if
] if ;
+<PRIVATE
+
:: (triangular-random-float) ( low high mode -- n )
mode low - high low - / :> c!
random-unit :> u!
u c > [ 1. u - u! 1. c - c! swap ] when
[ - u c * sqrt * ] keep + ;
+PRIVATE>
+
: triangular-random-float ( low high -- n )
2dup + 2 /f (triangular-random-float) ;
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