17 lines
532 B
Plaintext
17 lines
532 B
Plaintext
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( returns negative value on error )
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: _ ( c -- n )
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DUP '0' '9' =><= IF '0' - EXIT THEN
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DUP 'a' 'f' =><= IF 0x57 ( 'a' - 10 ) - EXIT THEN
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DROP -1 ( bad )
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;
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: _ph ( a -- n f, parse hex )
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( '0': ASCII 0x30 'x': 0x78 0x7830 )
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DUP 1+ @ 0x7830 = NOT IF 0 EXIT THEN ( a 0 )
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( We have "0x" prefix )
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DUP C@ ( a len )
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0 SWAP 1+ ( len+1 ) 3 DO ( a r )
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OVER I + C@ ( a r c ) _ ( a r n )
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DUP 0< IF 2DROP 0 UNLOOP EXIT THEN
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SWAP 4 LSHIFT + ( a r*16+n ) LOOP
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NIP 1 ;
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