freebsd-dev/sys/boot/ficl/softwords/ifbrack.fr

\ ** ficl/softwords/ifbrack.fr
\ ** ANS conditional compile directives [if] [else] [then]
\ ** Requires ficl 2.0 or greater...

\ $FreeBSD$

hide

: ?[if]   ( c-addr u -- c-addr u flag )
    2dup 2dup
    s" [if]" compare 0= >r
    s" [IF]" compare 0= r> 
    or
;

: ?[else]   ( c-addr u -- c-addr u flag )
    2dup 2dup
    s" [else]" compare 0= >r
    s" [ELSE]" compare 0= r> 
    or
;

: ?[then]   ( c-addr u -- c-addr u flag )
    2dup 2dup
    s" [then]" compare 0= >r
    s" [THEN]" compare 0= r> 
    or
;

set-current

: [else]  ( -- )
    1                                     \ ( level )
    begin
      begin
        parse-word dup  while             \ ( level addr len )
        ?[if] if                          \ ( level addr len )
            2drop 1+                      \ ( level )
        else                              \ ( level addr len )
            ?[else] if                    \ ( level addr len )
                 2drop 1- dup if 1+ endif
            else
                ?[then] if 2drop 1- else 2drop endif 
            endif
        endif ?dup 0=  if exit endif      \ level
      repeat  2drop                       \ level
    refill 0= until                       \ level
    drop
;  immediate

: [if]  ( flag -- )
0= if postpone [else] then ;  immediate

: [then]  ( -- )  ;  immediate

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