( requires core, str )
( string being sent to parse routines are always null
terminated )
: (parsec) ( a -- n f )
( apostrophe is ASCII 39 )
DUP C@ 39 = NOT IF 0 EXIT THEN ( a 0 )
DUP 2 + C@ 39 = NOT IF 0 EXIT THEN ( a 0 )
( surrounded by apos, good, return )
1 + C@ 1 ( n 1 )
;
( returns negative value on error )
: hexdig ( c -- n )
( '0' is ASCII 48 )
48 -
DUP 0 < IF EXIT THEN ( bad )
DUP 10 < IF EXIT THEN ( good )
( 'a' is ASCII 97. 59 = 97 - 48 )
49 -
DUP 0 < IF EXIT THEN ( bad )
DUP 6 < IF 10 + EXIT THEN ( good )
( bad )
255 -
;
: (parseh) ( a -- n f )
( '0': ASCII 0x30 'x': 0x78 0x7830: 30768 )
DUP @ 30768 = NOT IF 0 EXIT THEN ( a 0 )
( We have "0x" prefix )
2 +
( validate slen )
DUP SLEN ( a l )
DUP 0 = IF DROP 0 EXIT THEN ( a 0 )
4 > IF DROP 0 EXIT THEN ( a 0 )
0 ( a r )
BEGIN
OVER C@
DUP 0 = IF DROP SWAP DROP 1 EXIT THEN ( r, 1 )
hexdig ( a r n )
DUP 0 < IF DROP DROP 1 EXIT THEN ( a 0 )
SWAP 16 * + ( a r*16+n )
SWAP 1 + SWAP ( a+1 r )
AGAIN
;
( returns negative value on error )
: bindig ( c -- n )
( '0' is ASCII 48 )
48 -
DUP 0 < IF EXIT THEN ( bad )
DUP 2 < IF EXIT THEN ( good )
( bad )
255 -
;
: (parseb) ( a -- n f )
( '0': ASCII 0x30 'b': 0x62 0x6230: 25136 )
DUP @ 25136 = NOT IF 0 EXIT THEN ( a 0 )
( We have "0b" prefix )
2 +
( validate slen )
DUP SLEN ( a l )
DUP 0 = IF DROP 0 EXIT THEN ( a 0 )
16 > IF DROP 0 EXIT THEN ( a 0 )
0 ( a r )
BEGIN
OVER C@
DUP 0 = IF DROP SWAP DROP 1 EXIT THEN ( r, 1 )
bindig ( a r n )
DUP 0 < IF DROP DROP 1 EXIT THEN ( a 0 )
SWAP 2 * + ( a r*2+n )
SWAP 1 + SWAP ( a+1 r )
AGAIN
;
: (parse) ( a -- n )
(parsec) IF EXIT THEN
(parseh) IF EXIT THEN
(parseb) IF EXIT THEN
(parsed) IF EXIT THEN
( nothing works )
ABORT" unknown word! "
;
