Re: Reverse SCAN SPLIT

On 7/10/2024 7:52 pm, dxf wrote:

Earlier I mentioned scanning in reverse.  Here's an implementation.
 
[undefined] dxforth [if]
: \CHAR ( a u -- a2 u2 c )  1- 2dup + c@ ;
[then]
 
\ As for SCAN but scan from end
: SCAN< ( a u c -- a2 u2 | a 0 )
  >r over swap begin dup while \char r@ = until 1+ then
  rot drop rdrop ;

Cleaned-up version:

: SCAN< ( a u c -- a2 u2 | a 0 )
  >r begin dup while \char r@ = until 1+ then r> drop ;

\ As for SPLIT but scan from end. Latter string is topmost.
: SPLIT< ( a u c -- a2 u2 a3 u3 )
  >r 2dup r> scan< 2swap 2 pick /string ;