forth/lib/split.fs

   1 \ implements split-before, split-after and left-split
   2 \ as described in 4.3 (Path resolution)
   3
   4 \ delimeter returned in R-string
   5 : split-before ( addr len delim -- addr-R len-R addr-L len-L )
   6   0 rot dup >r 0 ?do
   7     ( str char cnt R: len <sys> )
   8     2 pick over + c@ 2 pick = if leave then
   9     1+
  10   loop
  11   nip
  12   2dup + r> 2 pick -
  13   2swap
  14 ;
  15
  16 \ delimeter returned in L-string
  17 : split-after ( addr len delim -- addr-R len-R addr-L len-L )
  18   over 1- rot dup >r 0 ?do
  19     ( str char cnt R: len <sys> )
  20     2 pick over + c@ 2 pick = if leave then
  21     1-
  22         loop
  23   nip
  24         dup 0 >= if 1+ else drop r@ then
  25         2dup + r> 2 pick -
  26   2swap
  27 ;
  28
  29 \ delimiter not returned
  30 : left-split ( addr len delim -- addr-R len-R addr-L len-L )
  31   0 rot dup >r 0 ?do
  32     ( str char cnt R: len <sys> )
  33     2 pick i + c@ 2 pick = if leave then
  34     1+
  35   loop
  36   nip
  37   2dup + 1+ r> 2 pick -
  38   dup if 1- then
  39   2swap
  40 ;
  41
  42 \ delimiter not returned [THIS FUNCTION IS NOT NEEDED]
  43 : right-split ( addr len delim -- addr-R len-R addr-L len-L )
  44         dup >r
  45         split-after
  46         dup if 2dup + 1-
  47                 c@ r@ = if 1- then then
  48         r> drop
  49 ;
  50
  51 \ split <param-text> into separate path and device strings
  52 : split-path-device  ( str len -- pathstr len devstr len )
  53   ascii , left-split 2 pick 0= if
  54     \ No comma - so either <dev>:<id> or <dev>:<id><path>
  55     2dup ascii \ strchr 0= if
  56       \ No backslash so just <dev> or <dev>:<id>
  57       s" " 2swap        \ ( pathstr len devstr len )
  58     else
  59       \ Contains backslash, must be a <dev>:<id><path>
  60       ascii : left-split        \ ( pathstr len devstr len )
  61     then
  62
  63     \ Remove RHS split (unused)
  64     4 roll drop
  65     4 roll drop
  66   else
  67     \ Contains comma so split is already correct
  68   then
  69 ;
  70