factor/extra/math/primes/primes.factor

50 lines
1.3 KiB
Factor

! Copyright (C) 2007 Samuel Tardieu.
! See http://factorcode.org/license.txt for BSD license.
USING: combinators kernel lazy-lists math math.functions math.miller-rabin
math.primes.list math.ranges sequences sorting ;
IN: math.primes
<PRIVATE
: find-prime-miller-rabin ( n -- p )
dup miller-rabin [ 2 + find-prime-miller-rabin ] unless ; foldable
PRIVATE>
: next-prime ( n -- p )
dup 999983 < [
primes-under-million [ [ <=> ] binsearch 1+ ] keep nth
] [
next-odd find-prime-miller-rabin
] if ; foldable
: prime? ( n -- ? )
dup 1000000 < [
dup primes-under-million [ <=> ] binsearch* =
] [
miller-rabin
] if ; foldable
: lprimes ( -- list )
0 primes-under-million seq>list
1000003 [ 2 + find-prime-miller-rabin ] lfrom-by
lappend ;
: lprimes-from ( n -- list )
dup 3 < [ drop lprimes ] [ 1- next-prime [ next-prime ] lfrom-by ] if ;
: primes-upto ( n -- seq )
{
{ [ dup 2 < ] [ drop { } ] }
{ [ dup 1000003 < ]
[ primes-under-million [ [ <=> ] binsearch 1+ 0 swap ] keep <slice> ] }
{ [ t ]
[ primes-under-million 1000003 lprimes-from
rot [ <= ] curry lwhile list>array append ] }
} cond ; foldable
: primes-between ( low high -- seq )
primes-upto
>r 1- next-prime r>
[ [ <=> ] binsearch ] keep [ length ] keep <slice> ; foldable