1 ! Copyright (C) 2004, 2006 Slava Pestov.
2 ! See http://factorcode.org/license.txt for BSD license.
3 IN: math.ratios.private
4 USING: kernel kernel.private math math.functions
7 : fraction> ( a b -- a/b )
8 dup 1 number= [ drop ] [ <ratio> ] if ; inline
14 dup 0 < [ [ neg ] 2apply ] when
15 2dup gcd nip tuck /i >r /i r> fraction>
18 : 2>fraction ( a/b c/d -- a c b d )
19 [ >fraction ] 2apply swapd ; inline
21 : scale ( a/b c/d -- a*d b*c )
22 2>fraction >r * swap r> * swap ; inline
24 : ratio+d ( a/b c/d -- b*d )
25 denominator swap denominator * ; inline
28 2>fraction number= [ number= ] [ 2drop f ] if ;
30 M: ratio >fixnum >fraction /i >fixnum ;
31 M: ratio >bignum >fraction /i >bignum ;
32 M: ratio >float >fraction /f ;
35 M: ratio <= scale <= ;
37 M: ratio >= scale >= ;
39 M: ratio + 2dup scale + -rot ratio+d / ;
40 M: ratio - 2dup scale - -rot ratio+d / ;
41 M: ratio * 2>fraction * >r * r> / ;
43 M: ratio /i scale /i ;
44 M: ratio mod 2dup >r >r /i r> r> rot * - ;