1: \ Input handling (object oriented) 22oct00py
2:
3: \ Copyright (C) 2000,2003,2004,2005 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 ( -- addr u ) \ core-ext,file source
30: \G Return address @i{addr} and length @i{u} of the current input
31: \G buffer
32: input-method refill ( -- flag ) \ core-ext,block-ext,file-ext
33: \G Attempt to fill the input buffer from the input source. When
34: \G the input source is the user input device, attempt to receive
35: \G input into the terminal input device. If successful, make the
36: \G result the input buffer, set @code{>IN} to 0 and return true;
37: \G otherwise return false. When the input source is a block, add 1
38: \G to the value of @code{BLK} to make the next block the input
39: \G source and current input buffer, and set @code{>IN} to 0;
40: \G return true if the new value of @code{BLK} is a valid block
41: \G number, false otherwise. When the input source is a text file,
42: \G attempt to read the next line from the file. If successful,
43: \G make the result the current input buffer, set @code{>IN} to 0
44: \G and return true; otherwise, return false. A successful result
45: \G includes receipt of a line containing 0 characters.
46: input-method source-id ( -- 0 | -1 | fileid ) \ core-ext,file source-i-d
47: \G Return 0 (the input source is the user input device), -1 (the
48: \G input source is a string being processed by @code{evaluate}) or
49: \G a @i{fileid} (the input source is the file specified by
50: \G @i{fileid}).
51: | input-method (save-input) ( -- x1 .. xn n ) \ gforth
52: | input-method (restore-input) ( x1 .. xn n -- ) \ gforth
53: drop
54:
55: cell \ the first cell points to the method table
56: cell input-var >in ( -- addr ) \ core to-in
57: \G @code{input-var} variable -- @i{a-addr} is the address of a
58: \G cell containing the char offset from the start of the input
59: \G buffer to the start of the parse area.
60: cell input-var input-parse-start ( -- a-addr ) \ gforth
61: \G @code{input-var} variable -- @i{a-addr} is the address of a
62: \G cell containing a pointer to the start of the last parsed
63: \G string (but after skipped characters, if any); this is set
64: \G automatically by @code{parse}, @code{parse-name} and
65: \G @code{word}, but not if you set @code{>in} yourself.
66: cell input-var input-parse-end ( -- a-addr ) \ gforth
67: \G @code{input-var} variable -- @i{a-addr} is the address of a
68: \G cell containing a pointer to the end of the last parsed
69: \G string (but after skipped characters, if any); this is set
70: \G automatically by @code{parse}, @code{parse-name} and
71: \G @code{word}, but not if you set @code{>in} yourself.
72: cell input-var #tib ( -- addr ) \ core-ext number-t-i-b
73: \G @code{input-var} variable -- @i{a-addr} is the address of a
74: \G cell containing the number of characters in the terminal input
75: \G buffer. OBSOLESCENT: @code{source} superceeds the function of
76: \G this word.
77: cell input-var max#tib ( -- addr ) \ gforth max-number-t-i-b
78: \G @code{input-var} variable -- This cell contains the maximum
79: \G size of the current tib.
80: cell input-var old-input ( -- addr ) \ gforth
81: \G @code{input-var} variable -- This cell contains the pointer to
82: \G the previous input buffer
83: cell input-var loadline ( -- addr ) \ gforth
84: \G @code{input-var} variable -- This cell contains the line that's
85: \G currently loaded from
86: has? file [IF]
87: cell input-var loadfile ( -- addr ) \ gforth
88: \G @code{input-var} variable -- This cell contains the file the
89: \G input buffer is associated with (0 if none)
90: cell input-var blk ( -- addr ) \ block
91: \G @code{input-var} variable -- This cell contains the current
92: \G block number
93: cell input-var #fill-bytes ( -- addr ) \ gforth
94: \G @code{input-var} variable -- number of bytes read via
95: \G (read-line) by the last refill
96: 2 cells input-var loadfilename ( -- addr ) \ gforth
97: \G @code{input-var} variable -- addr u describes name of currently
98: \G interpreted input (file name or somesuch)
99: [THEN]
100: 0 input-var tib ( -- addr ) \ core
101:
102: Constant tib+
103:
104: \ helper words
105:
106: : input-start-line ( -- )
107: >in off input-parse-start off input-parse-end off ;
108:
109: : input-lexeme! ( c-addr u -- )
110: \ record that the current lexeme us c-addr u
111: >r source drop - dup input-parse-start ! r> + input-parse-end ! ;
112:
113: \ terminal input implementation
114:
115: :noname ( in 1 -- ) 1 <> -12 and throw >in ! ;
116: \ restore-input
117: :noname ( -- in 1 ) >in @ 1 ; \ save-input
118: ' false \ source-id
119: :noname ( -- flag ) [ has? file [IF] ]
120: stdin file-eof? IF false EXIT THEN [ [THEN] ]
121: tib max#tib @ accept #tib !
122: input-start-line true 1 loadline +! ; \ refill
123: :noname ( -- addr u ) tib #tib @ ; \ source
124:
125: | Create terminal-input A, A, A, A, A,
126: :noname ( -- addr u ) tib @ #tib @ ; \ source
127: | Create evaluate-input
128: A, \ source
129: ' false A, \ refill
130: ' true A, \ source-id
131: terminal-input 3 cells + @ A, \ terminal::restore-input
132: terminal-input 4 cells + @ A, \ terminal::save-input
133:
134: \ file input implementation
135:
136: has? file [IF]
137: : read-line ( c_addr u1 wfileid -- u2 flag wior ) \ file
138: (read-line) nip ;
139:
140: :noname ( in line# udpos 4 -- ) 4 <> -12 and throw
141: loadfile @ reposition-file throw
142: refill 0= -36 and throw \ should never throw
143: loadline ! >in ! ; \ restore-input
144: :noname ( -- in line# udpos 4 ) >in @ sourceline#
145: loadfile @ file-position throw #fill-bytes @ 0 d-
146: 4 ; \ save-input
147: :noname ( -- file ) loadfile @ ; \ source-id
148: :noname ( -- flag )
149: #tib off #fill-bytes off input-start-line
150: BEGIN
151: tib max#tib @ #tib @ /string
152: loadfile @ (read-line) throw #fill-bytes +!
153: swap #tib +!
154: \ auto-expanding the tib
155: dup #tib @ #fill-bytes @ = and WHILE
156: drop max#tib @ 2* expand-tib
157: REPEAT
158: 1 loadline +! ;
159: \ refill
160: terminal-input @ \ source -> terminal-input::source
161:
162: | Create file-input A, A, A, A, A,
163: [THEN]
164:
165: \ push-file, pop-file
166:
167: : new-tib ( method n -- ) \ gforth
168: \G Create a new entry of the tib stack, size @i{n}, method table
169: \G @i{method}.
170: dup >r tib+ + dup allocate throw tuck swap 0 fill
171: current-input @ swap current-input ! old-input ! r> max#tib !
172: current-input @ ! ;
173: : expand-tib ( n -- )
174: dup tib+ + current-input @ swap resize throw current-input !
175: max#tib ! tib max#tib @ #tib @ /string 0 fill ;
176: has? file [IF]
177: : push-file ( -- ) \ gforth
178: \G Create a new file input buffer
179: file-input def#tib new-tib ;
180: [THEN]
181: : pop-file ( throw-code -- throw-code ) \ gforth
182: \G pop and free the current top input buffer
183: dup IF
184: input-error-data >error
185: THEN
186: current-input @ old-input @ current-input ! free throw ;
187:
188: \ save-input, restore-input
189:
190: : save-input ( -- x1 .. xn n ) \ core-ext
191: \G The @i{n} entries @i{xn - x1} describe the current state of the
192: \G input source specification, in some platform-dependent way that can
193: \G be used by @code{restore-input}.
194: (save-input) current-input @ swap 1+ ;
195: : restore-input ( x1 .. xn n -- flag ) \ core-ext
196: \G Attempt to restore the input source specification to the state
197: \G described by the @i{n} entries @i{xn - x1}. @i{flag} is true if
198: \G the restore fails. In Gforth with the new input code, it fails
199: \G only with a flag that can be used to throw again; it is also
200: \G possible to save and restore between different active input
201: \G streams. Note that closing the input streams must happen in the
202: \G reverse order as they have been opened, but in between
203: \G everything is allowed.
204: current-input @ >r swap current-input ! 1- dup >r
205: ['] (restore-input) catch
206: dup IF r> 0 ?DO nip LOOP r> current-input ! EXIT THEN
207: rdrop rdrop ;
208:
209: \ create terminal input block
210:
211: : create-input ( -- )
212: \G create a new terminal input
213: terminal-input def#tib new-tib ;
214: \ s" *the terminal*" loadfilename 2!
215:
216: : execute-parsing-wrapper ( ... addr1 u1 xt addr2 u2 -- ... ) \ gforth-internal
217: \ addr1 u1 is the string to be processed, xt is the word for
218: \ processing it, addr2 u2 is the name of the input source
219: rot >r 2>r evaluate-input cell new-tib 2r>
220: [ has? file [IF] ]
221: loadfilename 2!
222: [ [ELSE] ]
223: 2drop
224: [ [THEN] ]
225: -1 loadline ! #tib ! tib !
226: r> catch pop-file throw ;
227:
228: : execute-parsing ( ... addr u xt -- ... ) \ gforth
229: \G Make @i{addr u} the current input source, execute @i{xt @code{(
230: \G ... -- ... )}}, then restore the previous input source.
231: s" *evaluated string*" execute-parsing-wrapper ;
232:
233: : evaluate ( ... addr u -- ... ) \ core,block
234: \G Save the current input source specification. Store @code{-1} in
235: \G @code{source-id} and @code{0} in @code{blk}. Set @code{>IN} to
236: \G @code{0} and make the string @i{c-addr u} the input source and
237: \G input buffer. Interpret. When the parse area is empty, restore the
238: \G input source specification.
239: ['] interpret execute-parsing ;
240:
241: \ clear tibstack
242:
243: : clear-tibstack ( -- ) \ gforth
244: \G clears the tibstack; if there is none, create the bottom entry:
245: \G the terminal input buffer.
246: current-input @ 0= IF create-input THEN
247: BEGIN old-input @ WHILE 0 pop-file drop REPEAT ;
248:
249: : query ( -- ) \ core-ext
250: \G Make the user input device the input source. Receive input into
251: \G the Terminal Input Buffer. Set @code{>IN} to zero. OBSOLESCENT:
252: \G superceeded by @code{accept}.
253: clear-tibstack refill 0= -39 and throw ;
254:
255: \ load a file
256:
257: has? file [IF]
258: defer line-end-hook ( -- ) \ gforth
259: \G called at every end-of-line when text-interpreting from a file
260: \ alternatively we could use a wrapper for REFILL
261: ' noop is line-end-hook
262:
263: : read-loop ( i*x -- j*x ) \ gforth
264: \G refill and interpret a file until EOF
265: BEGIN refill WHILE interpret line-end-hook REPEAT ;
266:
267: : execute-parsing-named-file ( i*x wfileid filename-addr filename-u xt -- j*x )
268: >r push-file \ dup 2* cells included-files 2@ drop + 2@ type
269: loadfilename 2! loadfile !
270: r> catch
271: loadfile @ close-file swap 2dup or
272: pop-file drop throw throw ;
273:
274: : execute-parsing-file ( i*x fileid xt -- j*x ) \ gforth
275: \G Make @i{fileid} the current input source, execute @i{xt @code{( i*x
276: \G -- j*x )}}, then restore the previous input source.
277: s" *a file*" rot execute-parsing-named-file ;
278:
279: : include-file ( i*x wfileid -- j*x ) \ file
280: \G Interpret (process using the text interpreter) the contents of
281: \G the file @var{wfileid}.
282: ['] read-loop execute-parsing-file ;
283: [THEN]
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