2020-10-28 18:06:58 -04:00
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: _pd ( a -- n f, parse decimal )
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( We read the first char outside of the loop because it *has*
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to be nonzero, which means _pdacc *has* to return 0. )
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C@+ OVER C@ 0 ( a len firstchar startat )
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( if we have '-', we only advance. more processing later. )
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SWAP '-' = IF 1+ THEN ( a len startat )
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( We loop until _pdacc is nonzero, which means either WS or
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non-digit. 1 means WS, which means parsing was a success.
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-1 means non-digit, which means we have a non-decimal. )
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0 ROT ROT ( len ) ( startat ) DO ( a r )
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OVER I + C@ ( a r c ) _pdacc ( a r f )
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IF DROP 1- 0 UNLOOP EXIT THEN LOOP ( a r )
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( if we had '-', we need to invert result. )
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SWAP C@ '-' = IF 0 -^ THEN 1 ( r 1 ) ;
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