1 ! Copyright (C) 2007-2009 Samuel Tardieu.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: combinators kernel math math.functions math.miller-rabin
4 math.order math.primes.erato math.ranges sequences ;
9 : look-in-bitmap ( n -- ? ) >index 4999999 sieve nth ;
11 : really-prime? ( n -- ? )
12 dup 5000000 < [ look-in-bitmap ] [ miller-rabin ] if ; foldable
18 { [ dup 2 < ] [ drop f ] }
19 { [ dup even? ] [ 2 = ] }
23 : next-prime ( n -- p )
24 next-odd [ dup really-prime? ] [ 2 + ] until ; foldable
26 : primes-between ( low high -- seq )
27 [ dup 3 max dup even? [ 1 + ] when ] dip
28 2 <range> [ prime? ] filter
29 swap 3 < [ 2 prefix ] when ;
31 : primes-upto ( n -- seq ) 2 swap primes-between ;
33 : coprime? ( a b -- ? ) gcd nip 1 = ; foldable