factor/library/math/math.factor

92 lines
2.6 KiB
Factor

! Copyright (C) 2003, 2005 Slava Pestov.
! See http://factor.sf.net/license.txt for BSD license.
IN: math
USING: errors generic kernel math-internals ;
! Math operations
G: number= ( x y -- ? ) math-combination ; foldable
M: object number= 2drop f ;
G: < ( x y -- ? ) math-combination ; foldable
G: <= ( x y -- ? ) math-combination ; foldable
G: > ( x y -- ? ) math-combination ; foldable
G: >= ( x y -- ? ) math-combination ; foldable
G: + ( x y -- x+y ) math-combination ; foldable
G: - ( x y -- x-y ) math-combination ; foldable
G: * ( x y -- x*y ) math-combination ; foldable
G: / ( x y -- x/y ) math-combination ; foldable
G: /i ( x y -- x/y ) math-combination ; foldable
G: /f ( x y -- x/y ) math-combination ; foldable
G: mod ( x y -- x%y ) math-combination ; foldable
G: /mod ( x y -- x/y x%y ) math-combination ; foldable
G: bitand ( x y -- z ) math-combination ; foldable
G: bitor ( x y -- z ) math-combination ; foldable
G: bitxor ( x y -- z ) math-combination ; foldable
G: shift ( x n -- y ) math-combination ; foldable
GENERIC: bitnot ( n -- n ) foldable
GENERIC: truncate ( n -- n ) foldable
GENERIC: floor ( n -- n ) foldable
GENERIC: ceiling ( n -- n ) foldable
: max ( x y -- z ) [ > ] 2keep ? ; inline
: min ( x y -- z ) [ < ] 2keep ? ; inline
: between? ( x min max -- ? )
#! Push if min <= x <= max. Handles case where min > max
#! by swapping them.
2dup > [ swap ] when >r dupd max r> min = ; foldable
: sq dup * ; inline
: neg 0 swap - ; inline
: recip 1 swap / ; inline
: rem ( x y -- x%y )
#! Like modulus, but always gives a positive result.
[ mod ] keep over 0 < [ + ] [ drop ] ifte ; inline
: sgn ( n -- -1/0/1 )
#! Push the sign of a real number.
dup 0 = [ drop 0 ] [ 1 < -1 1 ? ] ifte ; foldable
GENERIC: abs ( z -- |z| )
: align ( offset width -- offset )
2dup mod dup 0 number= [ 2drop ] [ - + ] ifte ; inline
: (repeat) ( i n quot -- )
pick pick >=
[ 3drop ] [ [ swap >r call 1 + r> ] keep (repeat) ] ifte ;
inline
: repeat ( n quot -- | quot: n -- n )
#! The loop counter is kept on the stack, and ranges from
#! 0 to n-1.
0 -rot (repeat) ; inline
: times ( n quot -- | quot: -- )
swap [ >r dup slip r> ] repeat drop ; inline
: power-of-2? ( n -- ? )
dup 0 > [
dup dup neg bitand =
] [
drop f
] ifte ; foldable
: log2 ( n -- b )
#! Log base two for integers.
dup 0 <= [
"Input must be positive" throw
] [
dup 1 = [ drop 0 ] [ 2 /i log2 1 + ] ifte
] ifte ; foldable
GENERIC: string>number ( str -- num ) foldable
GENERIC: number>string ( str -- num ) foldable