48 lines
1.2 KiB
Factor
48 lines
1.2 KiB
Factor
! Copyright (C) 2004, 2005 Slava Pestov.
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! See http://factor.sf.net/license.txt for BSD license.
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IN: parser
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USING: errors generic kernel math sequences strings ;
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! Number parsing
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: not-a-number "Not a number" throw ;
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GENERIC: digit> ( ch -- n )
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M: digit digit> CHAR: 0 - ;
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M: letter digit> CHAR: a - 10 + ;
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M: LETTER digit> CHAR: A - 10 + ;
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M: object digit> not-a-number ;
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: digit+ ( num digit base -- num )
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2dup < [ rot * + ] [ not-a-number ] ifte ;
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: (base>) ( base str -- num )
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dup empty? [
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not-a-number
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] [
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0 [ digit> pick digit+ ] reduce nip
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] ifte ;
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: base> ( str base -- num )
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#! Convert a string to an integer. Throw an error if
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#! conversion fails.
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swap "-" ?head [ (base>) neg ] [ (base>) ] ifte ;
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GENERIC: str>number ( str -- num )
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M: string str>number 10 base> ;
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PREDICATE: string potential-ratio CHAR: / swap member? ;
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M: potential-ratio str>number ( str -- num )
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dup CHAR: / swap index swap cut*
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swap 10 base> swap 10 base> / ;
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PREDICATE: string potential-float CHAR: . swap member? ;
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M: potential-float str>number ( str -- num )
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str>float ;
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: bin> 2 base> ;
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: oct> 8 base> ;
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: dec> 10 base> ;
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: hex> 16 base> ;
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