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Use math.primes.erato instead of a list of first prime numbers

db4
Samuel Tardieu 2008-12-26 20:58:46 +01:00
parent 93b20967b5
commit f86b5baf8d
3 changed files with 24 additions and 27 deletions
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2
extra/math/primes/primes-docs.factor
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@ -4,7 +4,7 @@ IN: math.primes
{ next-prime prime? } related-words { next-prime prime? } related-words
HELP: next-prime HELP: next-prime
{ $values { "n" "a positive integer" } { "p" "a prime number" } } { $values { "n" "an integer not smaller than 2" } { "p" "a prime number" } }
{ $description "Return the next prime number greater than " { $snippet "n" } "." } ; { $description "Return the next prime number greater than " { $snippet "n" } "." } ;
HELP: prime? HELP: prime?

4
extra/math/primes/primes-tests.factor
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@ -8,3 +8,7 @@ USING: arrays math.primes tools.test lists.lazy ;
{ { 999983 1000003 } } [ 2 999982 lprimes-from ltake list>array ] unit-test { { 999983 1000003 } } [ 2 999982 lprimes-from ltake list>array ] unit-test
{ { 2 3 5 7 } } [ 10 primes-upto >array ] unit-test { { 2 3 5 7 } } [ 10 primes-upto >array ] unit-test
{ { 999983 1000003 } } [ 999982 1000010 primes-between >array ] unit-test { { 999983 1000003 } } [ 999982 1000010 primes-between >array ] unit-test
{ { 4999963 4999999 5000011 5000077 5000081 } }
[ 4999962 5000082 primes-between >array ]
unit-test

45
extra/math/primes/primes.factor
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@ -1,46 +1,39 @@
! Copyright (C) 2007 Samuel Tardieu. ! Copyright (C) 2007 Samuel Tardieu.
! See http://factorcode.org/license.txt for BSD license. ! See http://factorcode.org/license.txt for BSD license.
USING: binary-search combinators kernel lists.lazy math math.functions USING: binary-search combinators kernel lists.lazy math math.functions
math.miller-rabin math.primes.list sequences ; math.miller-rabin math.primes.erato math.ranges sequences ;
IN: math.primes IN: math.primes
<PRIVATE <PRIVATE
: find-prime-miller-rabin ( n -- p ) : look-in-bitmap ( n -- ? ) >index 4999999 sieve nth ;
[ dup miller-rabin ] [ 2 + ] [ ] until ; foldable
: really-prime? ( n -- ? )
dup 5000000 < [ look-in-bitmap ] [ miller-rabin ] if ; foldable
PRIVATE> PRIVATE>
: next-prime ( n -- p )
dup 999983 < [
primes-under-million [ natural-search drop 1+ ] keep nth
] [
next-odd find-prime-miller-rabin
] if ; foldable
: prime? ( n -- ? ) : prime? ( n -- ? )
dup 1000000 < [ {
dup primes-under-million natural-search nip = { [ dup 2 < ] [ drop f ] }
] [ { [ dup even? ] [ 2 = ] }
miller-rabin [ really-prime? ]
] if ; foldable } cond ; foldable
: lprimes ( -- list ) : next-prime ( n -- p )
0 primes-under-million seq>list next-odd [ dup really-prime? ] [ 2 + ] [ ] until ; foldable
1000003 [ 2 + find-prime-miller-rabin ] lfrom-by
lappend ; : lprimes ( -- list ) 2 [ next-prime ] lfrom-by ;
: lprimes-from ( n -- list ) : lprimes-from ( n -- list )
dup 3 < [ drop lprimes ] [ 1- next-prime [ next-prime ] lfrom-by ] if ; dup 3 < [ drop lprimes ] [ 1- next-prime [ next-prime ] lfrom-by ] if ;
: primes-upto ( n -- seq ) : primes-upto ( n -- seq )
{ dup 2 < [
{ [ dup 2 < ] [ drop { } ] } drop V{ }
{ [ dup 1000003 < ] [ ] [
primes-under-million [ natural-search drop 1+ 0 swap ] keep <slice> 3 swap 2 <range> [ prime? ] filter 2 prefix
] } ] if ; foldable
[ lprimes swap [ <= ] curry lwhile list>array ]
} cond ; foldable
: primes-between ( low high -- seq ) : primes-between ( low high -- seq )
primes-upto [ 1- next-prime ] dip primes-upto [ 1- next-prime ] dip