historical/m0-applesillicon.git/xnu-qemu-arm64-5.1.0/roms/openbios/forth/lib/split.fs
2024-01-16 11:20:27 -06:00

49 lines
1.1 KiB
Forth

\ implements split-before, split-after and left-split
\ as described in 4.3 (Path resolution)
\ delimeter returned in R-string
: split-before ( addr len delim -- addr-R len-R addr-L len-L )
0 rot dup >r 0 ?do
( str char cnt R: len <sys> )
2 pick over + c@ 2 pick = if leave then
1+
loop
nip
2dup + r> 2 pick -
2swap
;
\ delimeter returned in L-string
: split-after ( addr len delim -- addr-R len-R addr-L len-L )
over 1- rot dup >r 0 ?do
( str char cnt R: len <sys> )
2 pick over + c@ 2 pick = if leave then
1-
loop
nip
dup 0 >= if 1+ else drop r@ then
2dup + r> 2 pick -
2swap
;
\ delimiter not returned
: left-split ( addr len delim -- addr-R len-R addr-L len-L )
0 rot dup >r 0 ?do
( str char cnt R: len <sys> )
2 pick i + c@ 2 pick = if leave then
1+
loop
nip
2dup + 1+ r> 2 pick -
dup if 1- then
2swap
;
\ delimiter not returned [THIS FUNCTION IS NOT NEEDED]
: right-split ( addr len delim -- addr-R len-R addr-L len-L )
dup >r
split-after
dup if 2dup + 1-
c@ r@ = if 1- then then
r> drop
;