cscan
Scan string at addr1/n1 for the first c, leaving addr1/n2, char at n2 is first non-c character
Stackeffects
( addr1 n1 c -- addr1 n2 )R( -- )
Definition
: cscan
swap dup >r 0 (?do)
PFA_CSCAN1:
over i + c@ over =
(?branch) PFA_CSCAN2
drop i unloop r> drop exit
PFA_CSCAN2:
(loop) PFA_CSCAN1 ; ( -- addr1 c)
PFA_CSCAN3:
drop r>
;