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comparison interps/sceql/sceql-0.1.c @ 996:859f9b4339e6

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<Gregor> tar xf egobot.tar.xz
author HackBot
date Sun, 09 Dec 2012 19:30:08 +0000
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995:6883f5911eb7 996:859f9b4339e6
1 /*
2 The Sceql specification is not set in stone, so this
3 interpreter may change in the future. Version 0.1 of the specification
4 is implemented here.
5 */
6
7 #include <stdio.h>
8 #include <stdlib.h>
9 #include <limits.h>
10
11 #define NODESIZE 1000
12 #define LOOPDEPTH 1000
13
14 typedef unsigned char byte;
15
16 typedef struct byteqnode
17 {
18 byte qdata[NODESIZE];
19 int start; /* the first byte in use in qdata */
20 int end; /* the last byte in use in qdata */
21 struct byteqnode *next;
22 } byteqnode;
23
24 typedef struct
25 {
26 int len;
27 byteqnode *head, *tail;
28 } bytequeue;
29
30 void error(char *complaint)
31 {
32 fprintf(stderr, "%s\n", complaint);
33 exit(1);
34 }
35
36 /* create a queue with a zero byte in it */
37 bytequeue *queue_create(void)
38 {
39 bytequeue *myq;
40 myq = malloc(sizeof (bytequeue));
41 if (!myq)
42 error("Out of memory");
43 myq->len = 1;
44 myq->head = myq->tail = malloc(sizeof (byteqnode));
45 if (!myq->head)
46 error("Out of memory");
47 myq->tail->next = NULL;
48 myq->tail->start = myq->tail->end = 0;
49 myq->tail->qdata[0] = 0;
50 return myq;
51 }
52
53 /* add a byte onto the back of the queue */
54 void queue_enqueue(bytequeue *q, byte val)
55 {
56 byteqnode *node;
57 node = q->tail;
58 node->end++;
59 if (node->end == NODESIZE)
60 {
61 node = q->tail = node->next = malloc(sizeof (byteqnode));
62 if (!node)
63 error("Out of memory");
64 node->next = NULL;
65 node->start = node->end = 0;
66 }
67 node->qdata[node->end] = val;
68 q->len++;
69 }
70
71 byte queue_peek(bytequeue *q);
72
73 /* take a byte from the front of the queue */
74 byte queue_dequeue(bytequeue *q)
75 {
76 byte result;
77
78 result = queue_peek(q);
79
80 q->head->start++;
81 if (q->head->start == NODESIZE)
82 {
83 byteqnode *node = q->head->next;
84 free(q->head);
85 q->head = node;
86 /* q->head->start should already be 0 */
87 }
88 q->len--;
89 return result;
90 }
91
92 /* peek at a byte from the front of the queue */
93 byte queue_peek(bytequeue *q)
94 {
95 if (q->len == 0)
96 error("peeking at an empty queue");
97 return q->head->qdata[q->head->start];
98 }
99
100 /* shove a new byte at the front of the queue replacing what's there */
101 void queue_shove(bytequeue *q, byte b)
102 {
103 if (q->len == 0)
104 error("shoving into an empty queue");
105 q->head->qdata[q->head->start] = b;
106 }
107
108 void queue_delete(bytequeue *q)
109 {
110 byteqnode *node;
111 while (q->head)
112 {
113 node = q->head->next;
114 free(q->head);
115 q->head = node;
116 }
117 free(q);
118 }
119
120 #ifdef DEBUGGING
121 void queue_debug(bytequeue *q)
122 {
123 int i;
124 i = q->len;
125 if (i > 0)
126 {
127 byte b;
128 b = queue_dequeue(q);
129 printf("%d", b);
130 queue_enqueue(q, b);
131 }
132 for (i--; i > 0; i--)
133 {
134 byte b;
135 b = queue_dequeue(q);
136 printf(", %d", b);
137 queue_enqueue(q, b);
138 }
139 putchar('\n');
140 }
141 #endif
142
143 typedef enum
144 {
145 IN_NEXT = 0x01,
146 IN_DEC = 0x02,
147 IN_INPUT = 0x03,
148 IN_OUTPUT = 0x04,
149 IN_INC = 0x05,
150 IN_GROW = 0x06,
151 IN_BEGIN = 0x10,
152 IN_END = 0x11
153 #ifdef DEBUGGING
154 ,IN_DEBUG = 0xff
155 #endif
156 } sceql_intype;
157
158 typedef struct
159 {
160 sceql_intype in;
161 int r;
162 } sceql_instruction;
163
164 typedef struct
165 {
166 sceql_instruction *code;
167 int len;
168 } sceql_program;
169
170 sceql_intype sceql_getinstruction(FILE *f)
171 {
172 static sceql_intype uc2i[UCHAR_MAX + 1] = { IN_BEGIN };
173 int c;
174 sceql_intype i;
175 if (uc2i[0] == IN_BEGIN)
176 {
177 uc2i[0] = 0;
178 for (c = 1; c <= (int) UCHAR_MAX; c++)
179 {
180 i = 0;
181 if (c == '\\')
182 i = IN_BEGIN;
183 else if (c == '/')
184 i = IN_END;
185 else if (c == '=')
186 i = IN_NEXT;
187 else if (c == '-')
188 i = IN_DEC;
189 else if (c == '_')
190 i = IN_INC;
191 else if (c == '!')
192 i = IN_GROW;
193 else if (c == '&')
194 i = IN_INPUT;
195 else if (c == '*')
196 i = IN_OUTPUT;
197 #ifdef DEBUGGING
198 else if (c == '`')
199 i = IN_DEBUG;
200 #endif
201 uc2i[c] = i;
202 }
203 }
204 for (;;)
205 {
206 c = fgetc(f);
207 if (c < 0 || c > 255)
208 return 0;
209 if ((i = uc2i[c]))
210 break;
211 }
212 return i;
213 }
214
215 void sceql_load(sceql_program *p, FILE *f)
216 {
217 sceql_instruction *code;
218 sceql_intype in;
219 unsigned long filesize;
220 int last = 0, depth = 0, begin[LOOPDEPTH];
221
222 fseek(f, 0, SEEK_END);
223 filesize = ftell(f);
224 if (filesize > INT_MAX)
225 error("File too long");
226 fseek(f, 0, SEEK_SET);
227
228 code = p->code = malloc(filesize * sizeof (sceql_instruction));
229 if (!code)
230 error("Not enough memory");
231
232 if (!(in = sceql_getinstruction(f)))
233 error("Program contains no instructions");
234 if (in == IN_END)
235 error("Unbalanced slashes");
236 if (in == IN_BEGIN)
237 begin[depth++] = 0;
238 code[0].in = in;
239 code[0].r = 1;
240
241 while ((in = sceql_getinstruction(f)))
242 {
243 if (in == IN_BEGIN)
244 {
245 last++;
246 if (depth < LOOPDEPTH)
247 begin[depth] = last;
248 depth++;
249 }
250 else if (in == IN_END && depth <= LOOPDEPTH)
251 {
252 if (!depth)
253 error("Unbalanced slashes");
254 last++;
255 code[last].r = last - begin[--depth];
256 code[begin[depth]].r = code[last].r + 1;
257 }
258 else if (in == IN_END)
259 {
260 int mydepth = depth, start;
261 for (start = last++; start >= 0; start--)
262 {
263 if (code[start].in == IN_BEGIN)
264 {
265 if (mydepth == depth)
266 break;
267 mydepth--;
268 }
269 else if (code[start].in == IN_END)
270 mydepth++;
271 }
272 code[last].r = last - start;
273 code[start].r = code[last].r + 1;
274 depth--;
275 }
276 else
277 {
278 if (in == code[last].in)
279 {
280 code[last].r++;
281 continue;
282 }
283 code[++last].r = 1;
284 }
285 code[last].in = in;
286 }
287 fclose(f);
288 if (depth)
289 error("Unbalanced slashes");
290 p->len = last + 1;
291 }
292
293 void sceql_run(sceql_program *p)
294 {
295 bytequeue *q;
296 sceql_instruction *ip, *end;
297
298 ip = p->code;
299 end = ip + p->len;
300
301 q = queue_create();
302
303 do
304 {
305 register sceql_intype in;
306 register int r;
307
308 in = ip->in;
309 r = ip->r;
310
311 /* run the instruction "in": not just once, but "r" times */
312
313 if (in == IN_NEXT)
314 {
315 register byte b;
316 for (; r; r--)
317 {
318 b = queue_dequeue(q);
319 queue_enqueue(q, b);
320 }
321 }
322
323 /* it just so happens that we can increment or decrement
324 r times with a one-liner */
325 else if (in == IN_INC)
326 queue_shove(q, queue_peek(q) + r);
327 else if (in == IN_DEC)
328 queue_shove(q, queue_peek(q) - r);
329
330 else if (in == IN_GROW)
331 {
332 for (; r; r--)
333 queue_enqueue(q, 0);
334 }
335 else if (in == IN_OUTPUT)
336 {
337 register int c;
338 for (; r; r--)
339 {
340 c = queue_dequeue(q);
341 putchar(c);
342 queue_enqueue(q, c);
343 }
344 }
345 else if (in == IN_INPUT)
346 {
347 register int c;
348 for (; r; r--)
349 {
350 c = getchar();
351 if (c == EOF)
352 c = 0;
353 queue_enqueue(q, c);
354 }
355 }
356 else if (in == IN_BEGIN)
357 {
358 register byte b;
359 if (!(b = queue_peek(q)))
360 {
361 ip += r;
362 continue;
363 }
364 }
365 #ifdef DEBUGGING
366 else if (in == IN_DEBUG)
367 queue_debug(q);
368 #endif
369 else /* in == IN_END */
370 {
371 ip -= r;
372 continue;
373 }
374 ip++;
375 } while (ip < end);
376
377 queue_delete(q);
378 }
379
380 void sceql_freeup(sceql_program *p)
381 {
382 free(p->code);
383 }
384
385 void sceql_do(FILE *f)
386 {
387 sceql_program prog;
388 sceql_load(&prog, f);
389 sceql_run(&prog);
390 sceql_freeup(&prog);
391 }
392
393 int main(int argc, char *argv[])
394 {
395 FILE *codesrc = stdin;
396 if (argc != 2)
397 error("usage: sceql [sourcefile.sceql]");
398 if (!(codesrc = fopen(argv[1], "r")))
399 {
400 error("Unable to open file");
401 }
402 sceql_do(codesrc);
403 return 0;
404 }