41 lines
1 KiB
Forth
41 lines
1 KiB
Forth
\ *****************************************************************************
|
|
\ * Copyright (c) 2004, 2008 IBM Corporation
|
|
\ * All rights reserved.
|
|
\ * This program and the accompanying materials
|
|
\ * are made available under the terms of the BSD License
|
|
\ * which accompanies this distribution, and is available at
|
|
\ * http://www.opensource.org/licenses/bsd-license.php
|
|
\ *
|
|
\ * Contributors:
|
|
\ * IBM Corporation - initial implementation
|
|
\ ****************************************************************************/
|
|
|
|
: ([IF])
|
|
BEGIN
|
|
BEGIN parse-word dup 0= WHILE
|
|
2drop refill
|
|
REPEAT
|
|
|
|
2dup s" [IF]" str= IF 1 throw THEN
|
|
2dup s" [ELSE]" str= IF 2 throw THEN
|
|
2dup s" [THEN]" str= IF 3 throw THEN
|
|
s" \" str= IF linefeed parse 2drop THEN
|
|
AGAIN
|
|
;
|
|
|
|
: [IF] ( flag -- )
|
|
IF exit THEN
|
|
1 BEGIN
|
|
['] ([IF]) catch
|
|
CASE
|
|
1 OF 1+ ENDOF
|
|
2 OF dup 1 = if 1- then ENDOF
|
|
3 OF 1- ENDOF
|
|
ENDCASE
|
|
dup 0 <=
|
|
UNTIL drop
|
|
; immediate
|
|
|
|
: [ELSE] 0 [COMPILE] [IF] ; immediate
|
|
: [THEN] ; immediate
|
|
|