1: \ Copyright (C) 1995,1998,2000 Free Software Foundation, Inc.
2:
3: \ This file is part of Gforth.
4:
5: \ Gforth is free software; you can redistribute it and/or
6: \ modify it under the terms of the GNU General Public License
7: \ as published by the Free Software Foundation; either version 2
8: \ of the License, or (at your option) any later version.
9:
10: \ This program is distributed in the hope that it will be useful,
11: \ but WITHOUT ANY WARRANTY; without even the implied warranty of
12: \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13: \ GNU General Public License for more details.
14:
15: \ You should have received a copy of the GNU General Public License
16: \ along with this program; if not, write to the Free Software
17: \ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
18:
19: Warnings off
20:
21: Variable countif
22:
23: : dummy ; immediate
24: : >exec >r ; restrict ( :-)
25: : scanIF f83find dup 0= IF drop ['] dummy >head-noprim THEN ;
26:
27: Create [struct]-search ' scanIF A, ' (reveal) A, ' drop A, ' drop A,
28: Create [struct]-voc [struct]-search A,
29: NIL A, NIL A, NIL A,
30:
31: : ?if countif @ 0<
32: IF [ [struct]-voc 3 cells + ] ALiteral @ lookup ! THEN ;
33:
34: UNLOCK Tlast @ TNIL Tlast ! LOCK
35: \ last @ 0 last !
36:
37: : [IF]
38: 1 countif +! ?if ; immediate
39: : [THEN]
40: -1 countif +! ?if ; immediate
41: : [ELSE]
42: postpone [THEN] postpone [IF] ;
43: immediate
44: ' [IF] Alias [IFDEF] immediate
45: ' [IF] Alias [IFUNDEF] immediate
46: ' [THEN] Alias [ENDIF] immediate
47: ' [IF] Alias [BEGIN] immediate
48: ' [IF] Alias [WHILE] immediate
49: ' [THEN] Alias [UNTIL] immediate
50: ' [THEN] Alias [AGAIN] immediate
51: ' [IF] Alias [DO] immediate
52: ' [IF] Alias [?DO] immediate
53: ' [THEN] Alias [LOOP] immediate
54: ' [THEN] Alias [+LOOP] immediate
55: : [REPEAT] postpone [AGAIN] postpone [THEN] ;
56: immediate
57: ' ( Alias ( immediate
58: ' \ Alias \ immediate
59:
60: UNLOCK Tlast @ swap Tlast ! LOCK
61: \ last @ swap last !
62: 1 cells - [struct]-voc cell+ !
63:
64: \ Interpretative Structuren 30apr92py
65:
66: : defined bl word find nip 0<> ; immediate
67:
68: : [IF] ( flag | flag "<spaces>name ..." -- ) \ tools-ext bracket-if
69: \G If flag is @code{TRUE} do nothing (and therefore
70: \G execute subsequent words as normal). If flag is @code{FALSE},
71: \G parse and discard words from the parse
72: \G area (refilling it if necessary using
73: \G @code{REFILL}) including nested instances of @code{[IF]}..
74: \G @code{[ELSE]}.. @code{[THEN]} and @code{[IF]}.. @code{[THEN]}
75: \G until the balancing @code{[ELSE]} or @code{[THEN]} has been
76: \G parsed and discarded. Immediate word.
77: 0= IF countif off
78: lookup @ [ [struct]-voc 3 cells + ] ALiteral !
79: [struct]-voc lookup !
80: THEN ; immediate
81:
82: : [IFDEF] ( "<spaces>name" -- ) \ gforth bracket-if-def
83: \G If name is found in the current search-order, behave like
84: \G @code{[IF]} with a @code{TRUE} flag, otherwise behave like
85: \G @code{[IF]} with a @code{FALSE} flag. Immediate word.
86: postpone defined postpone [IF] ; immediate
87:
88: : [IFUNDEF] ( "<spaces>name" -- ) \ gforth bracket-if-un-def
89: \G If name is not found in the current search-order, behave like
90: \G @code{[IF]} with a @code{TRUE} flag, otherwise behave like
91: \G @code{[IF]} with a @code{FALSE} flag. Immediate word.
92: postpone defined 0= postpone [IF] ; immediate
93:
94: : [ELSE] ( "<spaces>name ..." -- ) \ tools-ext bracket-else
95: \G Parse and discard words from the parse
96: \G area (refilling it if necessary using
97: \G @code{REFILL}) including nested instances of @code{[IF]}..
98: \G @code{[ELSE]}.. @code{[THEN]} and @code{[IF]}.. @code{[THEN]}
99: \G until the balancing @code{[THEN]} has been parsed and discarded.
100: \G @code{[ELSE]} only gets executed if the balancing @code{[IF]}
101: \G was @code{TRUE}; if it was @code{FALSE}, @code{[IF]} would
102: \G have parsed and discarded the @code{[ELSE]}, leaving the
103: \G subsequent words to be executed as normal.
104: \G Immediate word.
105: 0 postpone [IF] ; immediate
106:
107: : [THEN] ( -- ) \ tools-ext bracket-then
108: \G Do nothing; used as a marker for other words to parse
109: \G and discard up to. Immediate word.
110: ; immediate
111:
112: : [ENDIF] ( -- ) \ gforth bracket-end-if
113: \G Do nothing; synonym for @code{[THEN]}
114: ; immediate
115:
116: \ Structs for interpreter 28nov92py
117:
118: User (i)
119:
120: : [DO] ( n-limit n-index -- ) \ gforth bracket-do
121: >in @ -rot
122: DO I (i) ! dup >r >in ! interpret r> swap +LOOP drop ;
123: immediate
124:
125: : [?DO] ( n-limit n-index -- ) \ gforth bracket-question-do
126: 2dup = IF 2drop postpone [ELSE] ELSE postpone [DO] THEN ;
127: immediate
128:
129: : [+LOOP] ( n -- ) \ gforth bracket-question-plus-loop
130: rdrop rdrop ; immediate
131:
132: : [LOOP] ( -- ) \ gforth bracket-loop
133: 1 rdrop rdrop ; immediate
134:
135: : [FOR] ( n -- ) \ gforth bracket-for
136: 0 swap postpone [DO] ; immediate
137:
138: : [NEXT] ( n -- ) \ gforth bracket-next
139: -1 rdrop rdrop ; immediate
140:
141: :noname (i) @ ;
142: :noname (i) @ postpone Literal ;
143: interpret/compile: [I] ( -- n ) \ gforth bracket-i
144:
145: : [BEGIN] ( -- ) \ gforth bracket-begin
146: >in @ >r BEGIN r@ >in ! interpret UNTIL rdrop ; immediate
147:
148: ' [+LOOP] Alias [UNTIL] ( flag -- ) \ gforth bracket-until
149: immediate
150:
151: : [REPEAT] ( -- ) \ gforth bracket-repeat
152: false rdrop rdrop ; immediate
153:
154: ' [REPEAT] Alias [AGAIN] ( -- ) \ gforth bracket-again
155: immediate
156:
157: : [WHILE] ( flag -- ) \ gforth bracket-while
158: 0= IF postpone [ELSE] true rdrop rdrop 1 countif +! THEN ;
159: immediate
160:
161: Warnings on
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