openbios/forth/lib/split.fs

\ 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
;

\ split <param-text> into separate path and device strings
: split-path-device  ( str len -- pathstr len devstr len )
  ascii , left-split 2 pick 0= if
    \ No comma - so either <dev>:<id> or <dev>:<id><path>
    2dup ascii \ strchr 0= if
      \ No backslash so just <dev> or <dev>:<id>
      s" " 2swap	\ ( pathstr len devstr len )
    else
      \ Contains backslash, must be a <dev>:<id><path>
      ascii : left-split 	\ ( pathstr len devstr len )
    then

    \ Remove RHS split (unused)
    4 roll drop
    4 roll drop
  else
    \ Contains comma so split is already correct
  then
;