Annotation of gforth/kernel/toolsext.fs, revision 1.14
1.11 anton 1: \ Copyright (C) 1995,1998,2000 Free Software Foundation, Inc.
1.1 anton 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
1.12 anton 17: \ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
1.1 anton 18:
1.3 jwilke 19: Warnings off
1.1 anton 20:
21: Variable countif
22:
23: : dummy ; immediate
24: : >exec >r ; restrict ( :-)
1.10 anton 25: : scanIF f83find dup 0= IF drop ['] dummy >head-noprim THEN ;
1.1 anton 26:
1.2 jwilke 27: Create [struct]-search ' scanIF A, ' (reveal) A, ' drop A, ' drop A,
1.5 pazsan 28: Create [struct]-voc [struct]-search A,
29: NIL A, NIL A, NIL A,
1.1 anton 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:
1.8 crook 37: : [IF]
38: 1 countif +! ?if ; immediate
39: : [THEN]
40: -1 countif +! ?if ; immediate
41: : [ELSE]
42: postpone [THEN] postpone [IF] ;
1.1 anton 43: immediate
44: ' [IF] Alias [IFDEF] immediate
45: ' [IF] Alias [IFUNDEF] immediate
1.8 crook 46: ' [THEN] Alias [ENDIF] immediate
1.1 anton 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
1.13 pazsan 57: ' ( Alias ( immediate ( keep fontify happy)
1.1 anton 58: ' \ Alias \ immediate
59:
60: UNLOCK Tlast @ swap Tlast ! LOCK
61: \ last @ swap last !
1.5 pazsan 62: 1 cells - [struct]-voc cell+ !
1.1 anton 63:
64: \ Interpretative Structuren 30apr92py
65:
1.13 pazsan 66: : [defined] ( "<spaces>name" -- flag ) bl word find nip 0<> ; immediate
67: \G returns true if name is found in current search order
1.14 ! anton 68: ' [defined] alias defined immediate
1.13 pazsan 69: : [undefined] ( "<spaces>name" -- flag ) postpone [defined] 0= ; immediate
70: \G returns false if name is found in current search order
1.8 crook 71:
1.13 pazsan 72: : [IF] ( flag -- ) \ tools-ext bracket-if
1.8 crook 73: \G If flag is @code{TRUE} do nothing (and therefore
74: \G execute subsequent words as normal). If flag is @code{FALSE},
75: \G parse and discard words from the parse
76: \G area (refilling it if necessary using
77: \G @code{REFILL}) including nested instances of @code{[IF]}..
78: \G @code{[ELSE]}.. @code{[THEN]} and @code{[IF]}.. @code{[THEN]}
79: \G until the balancing @code{[ELSE]} or @code{[THEN]} has been
80: \G parsed and discarded. Immediate word.
81: 0= IF countif off
1.1 anton 82: lookup @ [ [struct]-voc 3 cells + ] ALiteral !
83: [struct]-voc lookup !
84: THEN ; immediate
1.8 crook 85:
86: : [IFDEF] ( "<spaces>name" -- ) \ gforth bracket-if-def
87: \G If name is found in the current search-order, behave like
1.9 crook 88: \G @code{[IF]} with a @code{TRUE} flag, otherwise behave like
1.8 crook 89: \G @code{[IF]} with a @code{FALSE} flag. Immediate word.
1.13 pazsan 90: postpone [defined] postpone [IF] ; immediate
1.8 crook 91:
92: : [IFUNDEF] ( "<spaces>name" -- ) \ gforth bracket-if-un-def
93: \G If name is not found in the current search-order, behave like
1.9 crook 94: \G @code{[IF]} with a @code{TRUE} flag, otherwise behave like
1.8 crook 95: \G @code{[IF]} with a @code{FALSE} flag. Immediate word.
1.13 pazsan 96: postpone [defined] 0= postpone [IF] ; immediate
1.8 crook 97:
1.13 pazsan 98: : [ELSE] ( -- ) \ tools-ext bracket-else
1.8 crook 99: \G Parse and discard words from the parse
100: \G area (refilling it if necessary using
101: \G @code{REFILL}) including nested instances of @code{[IF]}..
102: \G @code{[ELSE]}.. @code{[THEN]} and @code{[IF]}.. @code{[THEN]}
103: \G until the balancing @code{[THEN]} has been parsed and discarded.
104: \G @code{[ELSE]} only gets executed if the balancing @code{[IF]}
105: \G was @code{TRUE}; if it was @code{FALSE}, @code{[IF]} would
106: \G have parsed and discarded the @code{[ELSE]}, leaving the
107: \G subsequent words to be executed as normal.
108: \G Immediate word.
109: 0 postpone [IF] ; immediate
110:
111: : [THEN] ( -- ) \ tools-ext bracket-then
112: \G Do nothing; used as a marker for other words to parse
1.9 crook 113: \G and discard up to. Immediate word.
1.8 crook 114: ; immediate
115:
116: : [ENDIF] ( -- ) \ gforth bracket-end-if
1.9 crook 117: \G Do nothing; synonym for @code{[THEN]}
1.8 crook 118: ; immediate
1.1 anton 119:
120: \ Structs for interpreter 28nov92py
121:
122: User (i)
123:
1.8 crook 124: : [DO] ( n-limit n-index -- ) \ gforth bracket-do
125: >in @ -rot
1.1 anton 126: DO I (i) ! dup >r >in ! interpret r> swap +LOOP drop ;
127: immediate
1.8 crook 128:
129: : [?DO] ( n-limit n-index -- ) \ gforth bracket-question-do
130: 2dup = IF 2drop postpone [ELSE] ELSE postpone [DO] THEN ;
1.1 anton 131: immediate
1.8 crook 132:
133: : [+LOOP] ( n -- ) \ gforth bracket-question-plus-loop
134: rdrop rdrop ; immediate
135:
136: : [LOOP] ( -- ) \ gforth bracket-loop
137: 1 rdrop rdrop ; immediate
138:
139: : [FOR] ( n -- ) \ gforth bracket-for
140: 0 swap postpone [DO] ; immediate
141:
142: : [NEXT] ( n -- ) \ gforth bracket-next
143: -1 rdrop rdrop ; immediate
144:
1.4 pazsan 145: :noname (i) @ ;
146: :noname (i) @ postpone Literal ;
1.8 crook 147: interpret/compile: [I] ( -- n ) \ gforth bracket-i
148:
149: : [BEGIN] ( -- ) \ gforth bracket-begin
150: >in @ >r BEGIN r@ >in ! interpret UNTIL rdrop ; immediate
151:
152: ' [+LOOP] Alias [UNTIL] ( flag -- ) \ gforth bracket-until
1.1 anton 153: immediate
1.8 crook 154:
155: : [REPEAT] ( -- ) \ gforth bracket-repeat
156: false rdrop rdrop ; immediate
157:
158: ' [REPEAT] Alias [AGAIN] ( -- ) \ gforth bracket-again
159: immediate
160:
161: : [WHILE] ( flag -- ) \ gforth bracket-while
1.1 anton 162: 0= IF postpone [ELSE] true rdrop rdrop 1 countif +! THEN ;
163: immediate
164:
1.3 jwilke 165: Warnings on
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