[gforth] / gforth / kernel / input.fs  

gforth: gforth/kernel/input.fs


1 : pazsan 1.1 \ Input handling (object oriented) 22oct00py
2 :    
3 : anton 1.8 \ Copyright (C) 2000,2003 Free Software Foundation, Inc.
4 : pazsan 1.1
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 : pazsan 1.4 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 : pazsan 1.1 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 \ 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 #tib \ core-ext number-t-i-b
61 :     \G @code{input-var} variable -- @i{a-addr} is the address of a
62 :     \G cell containing the number of characters in the terminal input
63 :     \G buffer. OBSOLESCENT: @code{source} superceeds the function of
64 :     \G this word.
65 :     cell input-var max#tib \ gforth max-number-t-i-b
66 :     \G @code{input-var} variable -- This cell contains the maximum
67 :     \G size of the current tib.
68 :     cell input-var old-input \ gforth
69 :     \G @code{input-var} variable -- This cell contains the pointer to
70 :     \G the previous input buffer
71 :     cell input-var loadline \ gforth
72 :     \G @code{input-var} variable -- This cell contains the line that's
73 :     \G currently loaded from
74 :     has? file [IF]
75 :     cell input-var loadfile \ gforth
76 :     \G @code{input-var} variable -- This cell contains the file the
77 :     \G input buffer is associated with (0 if none)
78 :     cell input-var blk \ block
79 :     \G @code{input-var} variable -- This cell contains the current
80 :     \G block number
81 :     cell input-var #fill-bytes \ gforth
82 :     \G @code{input-var} variable -- number of bytes read via
83 :     \G (read-line) by the last refill
84 : anton 1.5 2 cells input-var loadfilename \ gforth
85 :     \G @code{input-var} variable -- addr u describes name of currently
86 :     \G interpreted input (file name or somesuch)
87 : pazsan 1.1 [THEN]
88 :     0 input-var tib
89 :    
90 :     Constant tib+
91 :    
92 :     \ terminal input implementation
93 :    
94 : pazsan 1.4 :noname ( in 1 -- ) 1 <> -12 and throw >in ! ;
95 : pazsan 1.1 \ restore-input
96 : pazsan 1.4 :noname ( -- in 1 ) >in @ 1 ; \ save-input
97 : pazsan 1.2 ' false \ source-id
98 : pazsan 1.4 :noname ( -- flag ) [ has? file [IF] ]
99 : pazsan 1.3 stdin file-eof? IF false EXIT THEN [ [THEN] ]
100 :     tib max#tib @ accept #tib !
101 : pazsan 1.1 >in off true 1 loadline +! ; \ refill
102 : pazsan 1.4 :noname ( -- addr u ) tib #tib @ ; \ source
103 : pazsan 1.1
104 :     | Create terminal-input A, A, A, A, A,
105 : pazsan 1.4 :noname ( -- addr u ) tib @ #tib @ ; \ source
106 : pazsan 1.1 | Create evaluate-input
107 : pazsan 1.2 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
112 : pazsan 1.1
113 :     \ file input implementation
114 :    
115 :     has? file [IF]
116 : pazsan 1.3 : read-line ( c_addr u1 wfileid -- u2 flag wior ) (read-line) nip ;
117 :    
118 : pazsan 1.4 :noname ( in line# udpos 4 -- ) 4 <> -12 and throw
119 : pazsan 1.1 loadfile @ reposition-file throw
120 :     refill 0= -36 and throw \ should never throw
121 :     loadline ! >in ! ; \ restore-input
122 : pazsan 1.4 :noname ( -- in line# udpos 4 ) >in @ sourceline#
123 : pazsan 1.1 loadfile @ file-position throw #fill-bytes @ 0 d-
124 :     4 ; \ save-input
125 : pazsan 1.4 :noname ( -- file ) loadfile @ ; \ source-id
126 :     :noname ( -- flag )
127 :     #tib off #fill-bytes off >in off
128 : pazsan 1.3 BEGIN
129 :     tib max#tib @ #tib @ /string
130 :     loadfile @ (read-line) throw #fill-bytes +!
131 :     swap #tib +!
132 :     \ auto-expanding the tib
133 :     dup #tib @ #fill-bytes @ = and WHILE
134 :     drop max#tib @ 2* expand-tib
135 :     REPEAT
136 :     1 loadline +! ;
137 : pazsan 1.1 \ refill
138 :     terminal-input @ \ source -> terminal-input::source
139 :    
140 :     | Create file-input A, A, A, A, A,
141 :     [THEN]
142 :    
143 :     \ push-file, pop-file
144 :    
145 :     : new-tib ( method n -- ) \ gforth
146 :     \G Create a new entry of the tib stack, size @i{n}, method table
147 :     \G @i{method}.
148 :     dup >r tib+ + dup allocate throw tuck swap 0 fill
149 :     current-input @ swap current-input ! old-input ! r> max#tib !
150 :     current-input @ ! ;
151 : pazsan 1.3 : expand-tib ( n -- )
152 :     dup tib+ + current-input @ swap resize throw current-input !
153 :     max#tib ! tib max#tib @ #tib @ /string 0 fill ;
154 : pazsan 1.1 has? file [IF]
155 :     : push-file ( -- ) \ gforth
156 :     \G Create a new file input buffer
157 :     file-input def#tib new-tib ;
158 :     [THEN]
159 :     : pop-file ( throw-code -- throw-code ) \ gforth
160 :     \G pop and free the current top input buffer
161 :     dup IF
162 :     source >in @ sourceline#
163 :     [ has? file [IF] ] sourcefilename [ [THEN] ]
164 :     >error
165 :     THEN
166 :     current-input @ old-input @ current-input ! free throw ;
167 :    
168 :     \ save-input, restore-input
169 :    
170 :     : save-input ( -- x1 .. xn n ) \ core-ext
171 :     \G The @i{n} entries @i{xn - x1} describe the current state of the
172 :     \G input source specification, in some platform-dependent way that can
173 :     \G be used by @code{restore-input}.
174 :     (save-input) current-input @ swap 1+ ;
175 :     : restore-input ( x1 .. xn n -- flag ) \ core-ext
176 :     \G Attempt to restore the input source specification to the state
177 :     \G described by the @i{n} entries @i{xn - x1}. @i{flag} is true if
178 :     \G the restore fails. In Gforth with the new input code, it fails
179 :     \G only with a flag that can be used to throw again; it is also
180 :     \G possible to save and restore between different active input
181 :     \G streams. Note that closing the input streams must happen in the
182 :     \G reverse order as they have been opened, but in between
183 :     \G everything is allowed.
184 :     current-input @ >r swap current-input ! 1- dup >r
185 :     ['] (restore-input) catch
186 :     dup IF r> 0 ?DO nip LOOP r> current-input ! EXIT THEN
187 :     rdrop rdrop ;
188 :    
189 :     \ create terminal input block
190 :    
191 :     : create-input ( -- )
192 :     \G create a new terminal input
193 :     terminal-input def#tib new-tib ;
194 : anton 1.5 \ s" *the terminal*" loadfilename 2!
195 : pazsan 1.1
196 : anton 1.6 : execute-parsing ( ... addr u xt -- ... )
197 :     \G Make @i{addr u} the current input source, execute @i{xt @code{(
198 :     \G ... -- ... )}}, then restore the previous input source.
199 :     >r evaluate-input cell new-tib
200 : pazsan 1.1 [ has? file [IF] ]
201 : anton 1.5 s" *evaluated string*" loadfilename 2!
202 : pazsan 1.1 [ [THEN] ]
203 : pazsan 1.2 -1 loadline ! #tib ! tib !
204 : anton 1.6 r> catch pop-file throw ;
205 :    
206 :     : evaluate ( ... addr u -- ... ) \ core,block
207 :     \G Save the current input source specification. Store @code{-1} in
208 :     \G @code{source-id} and @code{0} in @code{blk}. Set @code{>IN} to
209 :     \G @code{0} and make the string @i{c-addr u} the input source and
210 :     \G input buffer. Interpret. When the parse area is empty, restore the
211 :     \G input source specification.
212 :     ['] interpret execute-parsing ;
213 : pazsan 1.1
214 :     \ clear tibstack
215 :    
216 :     : clear-tibstack ( -- ) \ gforth
217 :     \G clears the tibstack; if there is none, create the bottom entry:
218 :     \G the terminal input buffer.
219 :     current-input @ 0= IF create-input THEN
220 :     BEGIN old-input @ WHILE 0 pop-file drop REPEAT ;
221 :    
222 :     : query ( -- ) \ core-ext
223 :     \G Make the user input device the input source. Receive input into
224 :     \G the Terminal Input Buffer. Set @code{>IN} to zero. OBSOLESCENT:
225 :     \G superceeded by @code{accept}.
226 :     clear-tibstack refill drop ;
227 :    
228 :     \ load a file
229 :    
230 :     has? file [IF]
231 : anton 1.9 defer line-end-hook ( -- ) \ gforth
232 :     \G called at every end-of-line when text-interpreting from a file
233 :     \ alternatively we could use a wrapper for REFILL
234 :     ' noop is line-end-hook
235 :    
236 : pazsan 1.1 : read-loop ( i*x -- j*x ) \ gforth
237 :     \G refill and interpret a file until EOF
238 : anton 1.9 BEGIN refill WHILE interpret line-end-hook REPEAT ;
239 : pazsan 1.1
240 : anton 1.7 : execute-parsing-named-file ( i*x wfileid filename-addr filename-u xt -- j*x )
241 :     >r push-file \ dup 2* cells included-files 2@ drop + 2@ type
242 : anton 1.5 loadfilename 2! loadfile !
243 : anton 1.7 r> catch
244 : pazsan 1.1 loadfile @ close-file swap 2dup or
245 :     pop-file drop throw throw ;
246 :    
247 : anton 1.7 : execute-parsing-file ( i*x fileid xt -- j*x )
248 :     \G Make @i{fileid} the current input source, execute @i{xt @code{( i*x
249 :     \G -- j*x )}}, then restore the previous input source.
250 :     s" *a file*" rot execute-parsing-named-file ;
251 :    
252 : pazsan 1.1 : include-file ( i*x wfileid -- j*x )
253 :     \G Interpret (process using the text interpreter) the contents of
254 :     \G the file @var{wfileid}.
255 : anton 1.7 ['] read-loop execute-parsing-file ;
256 : pazsan 1.1 [THEN]

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