Annotation of gforth/kernel/input.fs, revision 1.2
1.1 pazsan 1: \ Input handling (object oriented) 22oct00py
2:
3: \ Copyright (C) 2000 Free Software Foundation, Inc.
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
19: \ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
20:
21: \ input handling structure:
22:
23: | : input-method ( m "name" -- m' ) Create dup , cell+
24: DOES> ( ... -- ... ) @ current-input @ @ + perform ;
25: | : input-var ( v size "name" -- v' ) Create over , +
26: DOES> ( -- addr ) @ current-input @ + ;
27:
28: 0
29: input-method source ( -- 0 | -1 | fileid ) \ core-ext,file source-i-d
30: \G Return 0 (the input source is the user input device), -1 (the
31: \G input source is a string being processed by @code{evaluate}) or
32: \G a @i{fileid} (the input source is the file specified by
33: \G @i{fileid}).
34: input-method refill ( -- flag ) \ core-ext,block-ext,file-ext
35: \G Attempt to fill the input buffer from the input source. When
36: \G the input source is the user input device, attempt to receive
37: \G input into the terminal input device. If successful, make the
38: \G result the input buffer, set @code{>IN} to 0 and return true;
39: \G otherwise return false. When the input source is a block, add 1
40: \G to the value of @code{BLK} to make the next block the input
41: \G source and current input buffer, and set @code{>IN} to 0;
42: \G return true if the new value of @code{BLK} is a valid block
43: \G number, false otherwise. When the input source is a text file,
44: \G attempt to read the next line from the file. If successful,
45: \G make the result the current input buffer, set @code{>IN} to 0
46: \G and return true; otherwise, return false. A successful result
47: \G includes receipt of a line containing 0 characters.
48: input-method source-id ( -- 0 | -1 | fileid ) \ core-ext,file source-i-d
49: \G Return 0 (the input source is the user input device), -1 (the
50: \G input source is a string being processed by @code{evaluate}) or
51: \G a @i{fileid} (the input source is the file specified by
52: \G @i{fileid}).
53: | input-method (save-input) ( -- x1 .. xn n ) \ gforth
54: | input-method (restore-input) ( x1 .. xn n -- ) \ gforth
55: drop
56:
57: cell \ the first cell points to the method table
58: cell input-var >in \ core to-in
59: \G @code{input-var} variable -- @i{a-addr} is the address of a
60: \G cell containing the char offset from the start of the input
61: \G buffer to the start of the parse area.
62: cell input-var #tib \ core-ext number-t-i-b
63: \G @code{input-var} variable -- @i{a-addr} is the address of a
64: \G cell containing the number of characters in the terminal input
65: \G buffer. OBSOLESCENT: @code{source} superceeds the function of
66: \G this word.
67: cell input-var max#tib \ gforth max-number-t-i-b
68: \G @code{input-var} variable -- This cell contains the maximum
69: \G size of the current tib.
70: cell input-var old-input \ gforth
71: \G @code{input-var} variable -- This cell contains the pointer to
72: \G the previous input buffer
73: cell input-var loadline \ gforth
74: \G @code{input-var} variable -- This cell contains the line that's
75: \G currently loaded from
76: has? file [IF]
77: cell input-var loadfile \ gforth
78: \G @code{input-var} variable -- This cell contains the file the
79: \G input buffer is associated with (0 if none)
80: cell input-var blk \ block
81: \G @code{input-var} variable -- This cell contains the current
82: \G block number
83: cell input-var #fill-bytes \ gforth
84: \G @code{input-var} variable -- number of bytes read via
85: \G (read-line) by the last refill
86: cell input-var loadfilename# \ gforth
87: \G @code{input-var} variable -- This cell contains the index into
88: \G the file name array and allows to identify the loaded file.
89: [THEN]
90: 0 input-var tib
91:
92: Constant tib+
93:
94: \ terminal input implementation
95:
96: :noname 1 <> -12 and throw >in ! ;
97: \ restore-input
98: :noname >in @ 1 ; \ save-input
1.2 ! pazsan 99: ' false \ source-id
1.1 pazsan 100: :noname tib max#tib @ accept #tib !
101: >in off true 1 loadline +! ; \ refill
102: :noname tib #tib @ ; \ source
103:
104: | Create terminal-input A, A, A, A, A,
1.2 ! pazsan 105: :noname tib @ #tib @ ; \ source
1.1 pazsan 106: | Create evaluate-input
1.2 ! pazsan 107: A, \ source
! 108: ' false A, \ refill
! 109: ' true A, \ source-id
! 110: terminal-input 3 cells + @ A, \ terminal::restore-input
! 111: terminal-input 4 cells + @ A, \ terminal::save-input
1.1 pazsan 112:
113: \ file input implementation
114:
115: has? file [IF]
116: :noname 4 <> -12 and throw
117: loadfile @ reposition-file throw
118: refill 0= -36 and throw \ should never throw
119: loadline ! >in ! ; \ restore-input
120: :noname >in @ sourceline#
121: loadfile @ file-position throw #fill-bytes @ 0 d-
122: 4 ; \ save-input
123: :noname loadfile @ ; \ source-id
124: :noname tib max#tib @ loadfile @ (read-line) throw #fill-bytes !
125: swap #tib ! >in off 1 loadline +! ;
126: \ refill
127: terminal-input @ \ source -> terminal-input::source
128:
129: | Create file-input A, A, A, A, A,
130: [THEN]
131:
132: \ push-file, pop-file
133:
134: : new-tib ( method n -- ) \ gforth
135: \G Create a new entry of the tib stack, size @i{n}, method table
136: \G @i{method}.
137: dup >r tib+ + dup allocate throw tuck swap 0 fill
138: current-input @ swap current-input ! old-input ! r> max#tib !
139: current-input @ ! ;
140: has? file [IF]
141: : push-file ( -- ) \ gforth
142: \G Create a new file input buffer
143: file-input def#tib new-tib ;
144: [THEN]
145: : pop-file ( throw-code -- throw-code ) \ gforth
146: \G pop and free the current top input buffer
147: dup IF
148: source >in @ sourceline#
149: [ has? file [IF] ] sourcefilename [ [THEN] ]
150: >error
151: THEN
152: current-input @ old-input @ current-input ! free throw ;
153:
154: \ save-input, restore-input
155:
156: : save-input ( -- x1 .. xn n ) \ core-ext
157: \G The @i{n} entries @i{xn - x1} describe the current state of the
158: \G input source specification, in some platform-dependent way that can
159: \G be used by @code{restore-input}.
160: (save-input) current-input @ swap 1+ ;
161: : restore-input ( x1 .. xn n -- flag ) \ core-ext
162: \G Attempt to restore the input source specification to the state
163: \G described by the @i{n} entries @i{xn - x1}. @i{flag} is true if
164: \G the restore fails. In Gforth with the new input code, it fails
165: \G only with a flag that can be used to throw again; it is also
166: \G possible to save and restore between different active input
167: \G streams. Note that closing the input streams must happen in the
168: \G reverse order as they have been opened, but in between
169: \G everything is allowed.
170: current-input @ >r swap current-input ! 1- dup >r
171: ['] (restore-input) catch
172: dup IF r> 0 ?DO nip LOOP r> current-input ! EXIT THEN
173: rdrop rdrop ;
174:
175: \ create terminal input block
176:
177: : create-input ( -- )
178: \G create a new terminal input
179: terminal-input def#tib new-tib ;
180: ( loadfilename# off ) \ "*the terminal*"
181:
182: : evaluate ( addr u -- ) \ core,block
183: \G Save the current input source specification. Store @code{-1} in
184: \G @code{source-id} and @code{0} in @code{blk}. Set @code{>IN} to
185: \G @code{0} and make the string @i{c-addr u} the input source
186: \G and input buffer. Interpret. When the parse area is empty,
187: \G restore the input source specification.
1.2 ! pazsan 188: evaluate-input cell new-tib
1.1 pazsan 189: [ has? file [IF] ]
190: 1 loadfilename# ! \ "*evaluated string*"
191: [ [THEN] ]
1.2 ! pazsan 192: -1 loadline ! #tib ! tib !
1.1 pazsan 193: ['] interpret catch pop-file throw ;
194:
195: \ clear tibstack
196:
197: : clear-tibstack ( -- ) \ gforth
198: \G clears the tibstack; if there is none, create the bottom entry:
199: \G the terminal input buffer.
200: current-input @ 0= IF create-input THEN
201: BEGIN old-input @ WHILE 0 pop-file drop REPEAT ;
202:
203: : query ( -- ) \ core-ext
204: \G Make the user input device the input source. Receive input into
205: \G the Terminal Input Buffer. Set @code{>IN} to zero. OBSOLESCENT:
206: \G superceeded by @code{accept}.
207: clear-tibstack refill drop ;
208:
209: \ load a file
210:
211: has? file [IF]
212: : read-loop ( i*x -- j*x ) \ gforth
213: \G refill and interpret a file until EOF
214: BEGIN refill WHILE interpret REPEAT ;
215:
216: : include-file2 ( i*x wfileid loadfilename# -- j*x )
217: push-file \ dup 2* cells included-files 2@ drop + 2@ type
218: loadfilename# ! loadfile !
219: ['] read-loop catch
220: loadfile @ close-file swap 2dup or
221: pop-file drop throw throw ;
222:
223: : include-file ( i*x wfileid -- j*x )
224: \G Interpret (process using the text interpreter) the contents of
225: \G the file @var{wfileid}.
226: 3 include-file2 ;
227: [THEN]
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