Annotation of gforth/kernel/cbr.fs, revision 1.10
1.1 jwilke 1: \ Structural Conditionals, based on branches 12dec92py
2:
1.10 ! anton 3: \ Copyright (C) 1995,1996,1997,1999,2001,2003,2006 Free Software Foundation, Inc.
1.1 jwilke 4:
5: \ This file is part of Gforth.
6:
7: \ Gforth is free software; you can redistribute it and/or
8: \ modify it under the terms of the GNU General Public License
9: \ as published by the Free Software Foundation; either version 2
10: \ of the License, or (at your option) any later version.
11:
12: \ This program is distributed in the hope that it will be useful,
13: \ but WITHOUT ANY WARRANTY; without even the implied warranty of
14: \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15: \ GNU General Public License for more details.
16:
17: \ You should have received a copy of the GNU General Public License
18: \ along with this program; if not, write to the Free Software
1.3 anton 19: \ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
1.1 jwilke 20:
21: : ?struc ( flag -- ) abort" unstructured " ;
22: : sys? ( sys -- ) dup 0= ?struc ;
1.8 pazsan 23: : >mark ( -- sys ) here cell allot ;
24: : >resolve ( sys -- ) here swap
25: [ has? flash [IF] ] flash! [ [ELSE] ] ! [ [THEN] ] ;
1.7 pazsan 26: : <resolve ( sys -- ) , ;
1.1 jwilke 27:
28: : BUT sys? swap ; immediate restrict
29: : YET sys? dup ; immediate restrict
30:
31: \ Structural Conditionals 12dec92py
32:
1.4 jwilke 33: : AHEAD postpone branch >mark ; immediate restrict
34: : IF postpone ?branch >mark ; immediate restrict
1.8 pazsan 35: : THEN sys? ( dup @ ?struc ) >resolve ; immediate restrict
1.4 jwilke 36: : ELSE sys? postpone AHEAD swap postpone THEN ;
1.1 jwilke 37: immediate restrict
38:
39: ' THEN Alias ENDIF immediate restrict
40:
41: : BEGIN here ; immediate restrict
1.4 jwilke 42: : WHILE sys? postpone IF swap ; immediate restrict
43: : AGAIN sys? postpone branch <resolve ; immediate restrict
44: : UNTIL sys? postpone ?branch <resolve ; immediate restrict
45: : REPEAT over 0= ?struc postpone AGAIN postpone THEN ;
1.1 jwilke 46: immediate restrict
47:
1.9 pazsan 48: 0 CONSTANT case ( compilation -- case-sys ; run-time -- ) \ core-ext
49: immediate
50:
51: : of ( compilation -- of-sys ; run-time x1 x2 -- |x1 ) \ core-ext
52: \ !! the implementation does not match the stack effect
53: 1+ >r
54: postpone over postpone = postpone if postpone drop
55: r> ; immediate
56:
57: : endof ( compilation case-sys1 of-sys -- case-sys2 ; run-time -- ) \ core-ext end-of
58: >r postpone else r> ; immediate
59:
60: : endcase ( compilation case-sys -- ; run-time x -- ) \ core-ext end-case
61: postpone drop
62: 0 ?do postpone then loop ; immediate
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