root/src/lua-5.1.3/src/lbaselib.c

Revision 5c8778c4361d2ad3adc94ef98d804c6fa9e6ba7c, 16.5 kB (checked in by Theo Schlossnagle <jesus@omniti.com>, 10 years ago)

import lua... I'd like to write checkers in lua

  • Property mode set to 100644
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1 /*
2 ** $Id: lbaselib.c,v 1.191.1.4 2008/01/20 13:53:22 roberto Exp $
3 ** Basic library
4 ** See Copyright Notice in lua.h
5 */
6
7
8
9 #include <ctype.h>
10 #include <stdio.h>
11 #include <stdlib.h>
12 #include <string.h>
13
14 #define lbaselib_c
15 #define LUA_LIB
16
17 #include "lua.h"
18
19 #include "lauxlib.h"
20 #include "lualib.h"
21
22
23
24
25 /*
26 ** If your system does not support `stdout', you can just remove this function.
27 ** If you need, you can define your own `print' function, following this
28 ** model but changing `fputs' to put the strings at a proper place
29 ** (a console window or a log file, for instance).
30 */
31 static int luaB_print (lua_State *L) {
32   int n = lua_gettop(L);  /* number of arguments */
33   int i;
34   lua_getglobal(L, "tostring");
35   for (i=1; i<=n; i++) {
36     const char *s;
37     lua_pushvalue(L, -1);  /* function to be called */
38     lua_pushvalue(L, i);   /* value to print */
39     lua_call(L, 1, 1);
40     s = lua_tostring(L, -1);  /* get result */
41     if (s == NULL)
42       return luaL_error(L, LUA_QL("tostring") " must return a string to "
43                            LUA_QL("print"));
44     if (i>1) fputs("\t", stdout);
45     fputs(s, stdout);
46     lua_pop(L, 1);  /* pop result */
47   }
48   fputs("\n", stdout);
49   return 0;
50 }
51
52
53 static int luaB_tonumber (lua_State *L) {
54   int base = luaL_optint(L, 2, 10);
55   if (base == 10) {  /* standard conversion */
56     luaL_checkany(L, 1);
57     if (lua_isnumber(L, 1)) {
58       lua_pushnumber(L, lua_tonumber(L, 1));
59       return 1;
60     }
61   }
62   else {
63     const char *s1 = luaL_checkstring(L, 1);
64     char *s2;
65     unsigned long n;
66     luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range");
67     n = strtoul(s1, &s2, base);
68     if (s1 != s2) {  /* at least one valid digit? */
69       while (isspace((unsigned char)(*s2))) s2++;  /* skip trailing spaces */
70       if (*s2 == '\0') {  /* no invalid trailing characters? */
71         lua_pushnumber(L, (lua_Number)n);
72         return 1;
73       }
74     }
75   }
76   lua_pushnil(L);  /* else not a number */
77   return 1;
78 }
79
80
81 static int luaB_error (lua_State *L) {
82   int level = luaL_optint(L, 2, 1);
83   lua_settop(L, 1);
84   if (lua_isstring(L, 1) && level > 0) {  /* add extra information? */
85     luaL_where(L, level);
86     lua_pushvalue(L, 1);
87     lua_concat(L, 2);
88   }
89   return lua_error(L);
90 }
91
92
93 static int luaB_getmetatable (lua_State *L) {
94   luaL_checkany(L, 1);
95   if (!lua_getmetatable(L, 1)) {
96     lua_pushnil(L);
97     return 1;  /* no metatable */
98   }
99   luaL_getmetafield(L, 1, "__metatable");
100   return 1;  /* returns either __metatable field (if present) or metatable */
101 }
102
103
104 static int luaB_setmetatable (lua_State *L) {
105   int t = lua_type(L, 2);
106   luaL_checktype(L, 1, LUA_TTABLE);
107   luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,
108                     "nil or table expected");
109   if (luaL_getmetafield(L, 1, "__metatable"))
110     luaL_error(L, "cannot change a protected metatable");
111   lua_settop(L, 2);
112   lua_setmetatable(L, 1);
113   return 1;
114 }
115
116
117 static void getfunc (lua_State *L, int opt) {
118   if (lua_isfunction(L, 1)) lua_pushvalue(L, 1);
119   else {
120     lua_Debug ar;
121     int level = opt ? luaL_optint(L, 1, 1) : luaL_checkint(L, 1);
122     luaL_argcheck(L, level >= 0, 1, "level must be non-negative");
123     if (lua_getstack(L, level, &ar) == 0)
124       luaL_argerror(L, 1, "invalid level");
125     lua_getinfo(L, "f", &ar);
126     if (lua_isnil(L, -1))
127       luaL_error(L, "no function environment for tail call at level %d",
128                     level);
129   }
130 }
131
132
133 static int luaB_getfenv (lua_State *L) {
134   getfunc(L, 1);
135   if (lua_iscfunction(L, -1))  /* is a C function? */
136     lua_pushvalue(L, LUA_GLOBALSINDEX);  /* return the thread's global env. */
137   else
138     lua_getfenv(L, -1);
139   return 1;
140 }
141
142
143 static int luaB_setfenv (lua_State *L) {
144   luaL_checktype(L, 2, LUA_TTABLE);
145   getfunc(L, 0);
146   lua_pushvalue(L, 2);
147   if (lua_isnumber(L, 1) && lua_tonumber(L, 1) == 0) {
148     /* change environment of current thread */
149     lua_pushthread(L);
150     lua_insert(L, -2);
151     lua_setfenv(L, -2);
152     return 0;
153   }
154   else if (lua_iscfunction(L, -2) || lua_setfenv(L, -2) == 0)
155     luaL_error(L,
156           LUA_QL("setfenv") " cannot change environment of given object");
157   return 1;
158 }
159
160
161 static int luaB_rawequal (lua_State *L) {
162   luaL_checkany(L, 1);
163   luaL_checkany(L, 2);
164   lua_pushboolean(L, lua_rawequal(L, 1, 2));
165   return 1;
166 }
167
168
169 static int luaB_rawget (lua_State *L) {
170   luaL_checktype(L, 1, LUA_TTABLE);
171   luaL_checkany(L, 2);
172   lua_settop(L, 2);
173   lua_rawget(L, 1);
174   return 1;
175 }
176
177 static int luaB_rawset (lua_State *L) {
178   luaL_checktype(L, 1, LUA_TTABLE);
179   luaL_checkany(L, 2);
180   luaL_checkany(L, 3);
181   lua_settop(L, 3);
182   lua_rawset(L, 1);
183   return 1;
184 }
185
186
187 static int luaB_gcinfo (lua_State *L) {
188   lua_pushinteger(L, lua_getgccount(L));
189   return 1;
190 }
191
192
193 static int luaB_collectgarbage (lua_State *L) {
194   static const char *const opts[] = {"stop", "restart", "collect",
195     "count", "step", "setpause", "setstepmul", NULL};
196   static const int optsnum[] = {LUA_GCSTOP, LUA_GCRESTART, LUA_GCCOLLECT,
197     LUA_GCCOUNT, LUA_GCSTEP, LUA_GCSETPAUSE, LUA_GCSETSTEPMUL};
198   int o = luaL_checkoption(L, 1, "collect", opts);
199   int ex = luaL_optint(L, 2, 0);
200   int res = lua_gc(L, optsnum[o], ex);
201   switch (optsnum[o]) {
202     case LUA_GCCOUNT: {
203       int b = lua_gc(L, LUA_GCCOUNTB, 0);
204       lua_pushnumber(L, res + ((lua_Number)b/1024));
205       return 1;
206     }
207     case LUA_GCSTEP: {
208       lua_pushboolean(L, res);
209       return 1;
210     }
211     default: {
212       lua_pushnumber(L, res);
213       return 1;
214     }
215   }
216 }
217
218
219 static int luaB_type (lua_State *L) {
220   luaL_checkany(L, 1);
221   lua_pushstring(L, luaL_typename(L, 1));
222   return 1;
223 }
224
225
226 static int luaB_next (lua_State *L) {
227   luaL_checktype(L, 1, LUA_TTABLE);
228   lua_settop(L, 2);  /* create a 2nd argument if there isn't one */
229   if (lua_next(L, 1))
230     return 2;
231   else {
232     lua_pushnil(L);
233     return 1;
234   }
235 }
236
237
238 static int luaB_pairs (lua_State *L) {
239   luaL_checktype(L, 1, LUA_TTABLE);
240   lua_pushvalue(L, lua_upvalueindex(1));  /* return generator, */
241   lua_pushvalue(L, 1);  /* state, */
242   lua_pushnil(L);  /* and initial value */
243   return 3;
244 }
245
246
247 static int ipairsaux (lua_State *L) {
248   int i = luaL_checkint(L, 2);
249   luaL_checktype(L, 1, LUA_TTABLE);
250   i++;  /* next value */
251   lua_pushinteger(L, i);
252   lua_rawgeti(L, 1, i);
253   return (lua_isnil(L, -1)) ? 0 : 2;
254 }
255
256
257 static int luaB_ipairs (lua_State *L) {
258   luaL_checktype(L, 1, LUA_TTABLE);
259   lua_pushvalue(L, lua_upvalueindex(1));  /* return generator, */
260   lua_pushvalue(L, 1);  /* state, */
261   lua_pushinteger(L, 0);  /* and initial value */
262   return 3;
263 }
264
265
266 static int load_aux (lua_State *L, int status) {
267   if (status == 0)  /* OK? */
268     return 1;
269   else {
270     lua_pushnil(L);
271     lua_insert(L, -2);  /* put before error message */
272     return 2;  /* return nil plus error message */
273   }
274 }
275
276
277 static int luaB_loadstring (lua_State *L) {
278   size_t l;
279   const char *s = luaL_checklstring(L, 1, &l);
280   const char *chunkname = luaL_optstring(L, 2, s);
281   return load_aux(L, luaL_loadbuffer(L, s, l, chunkname));
282 }
283
284
285 static int luaB_loadfile (lua_State *L) {
286   const char *fname = luaL_optstring(L, 1, NULL);
287   return load_aux(L, luaL_loadfile(L, fname));
288 }
289
290
291 /*
292 ** Reader for generic `load' function: `lua_load' uses the
293 ** stack for internal stuff, so the reader cannot change the
294 ** stack top. Instead, it keeps its resulting string in a
295 ** reserved slot inside the stack.
296 */
297 static const char *generic_reader (lua_State *L, void *ud, size_t *size) {
298   (void)ud;  /* to avoid warnings */
299   luaL_checkstack(L, 2, "too many nested functions");
300   lua_pushvalue(L, 1);  /* get function */
301   lua_call(L, 0, 1);  /* call it */
302   if (lua_isnil(L, -1)) {
303     *size = 0;
304     return NULL;
305   }
306   else if (lua_isstring(L, -1)) {
307     lua_replace(L, 3);  /* save string in a reserved stack slot */
308     return lua_tolstring(L, 3, size);
309   }
310   else luaL_error(L, "reader function must return a string");
311   return NULL;  /* to avoid warnings */
312 }
313
314
315 static int luaB_load (lua_State *L) {
316   int status;
317   const char *cname = luaL_optstring(L, 2, "=(load)");
318   luaL_checktype(L, 1, LUA_TFUNCTION);
319   lua_settop(L, 3);  /* function, eventual name, plus one reserved slot */
320   status = lua_load(L, generic_reader, NULL, cname);
321   return load_aux(L, status);
322 }
323
324
325 static int luaB_dofile (lua_State *L) {
326   const char *fname = luaL_optstring(L, 1, NULL);
327   int n = lua_gettop(L);
328   if (luaL_loadfile(L, fname) != 0) lua_error(L);
329   lua_call(L, 0, LUA_MULTRET);
330   return lua_gettop(L) - n;
331 }
332
333
334 static int luaB_assert (lua_State *L) {
335   luaL_checkany(L, 1);
336   if (!lua_toboolean(L, 1))
337     return luaL_error(L, "%s", luaL_optstring(L, 2, "assertion failed!"));
338   return lua_gettop(L);
339 }
340
341
342 static int luaB_unpack (lua_State *L) {
343   int i, e, n;
344   luaL_checktype(L, 1, LUA_TTABLE);
345   i = luaL_optint(L, 2, 1);
346   e = luaL_opt(L, luaL_checkint, 3, luaL_getn(L, 1));
347   n = e - i + 1;  /* number of elements */
348   if (n <= 0) return 0;  /* empty range */
349   luaL_checkstack(L, n, "table too big to unpack");
350   for (; i<=e; i++)  /* push arg[i...e] */
351     lua_rawgeti(L, 1, i);
352   return n;
353 }
354
355
356 static int luaB_select (lua_State *L) {
357   int n = lua_gettop(L);
358   if (lua_type(L, 1) == LUA_TSTRING && *lua_tostring(L, 1) == '#') {
359     lua_pushinteger(L, n-1);
360     return 1;
361   }
362   else {
363     int i = luaL_checkint(L, 1);
364     if (i < 0) i = n + i;
365     else if (i > n) i = n;
366     luaL_argcheck(L, 1 <= i, 1, "index out of range");
367     return n - i;
368   }
369 }
370
371
372 static int luaB_pcall (lua_State *L) {
373   int status;
374   luaL_checkany(L, 1);
375   status = lua_pcall(L, lua_gettop(L) - 1, LUA_MULTRET, 0);
376   lua_pushboolean(L, (status == 0));
377   lua_insert(L, 1);
378   return lua_gettop(L);  /* return status + all results */
379 }
380
381
382 static int luaB_xpcall (lua_State *L) {
383   int status;
384   luaL_checkany(L, 2);
385   lua_settop(L, 2);
386   lua_insert(L, 1);  /* put error function under function to be called */
387   status = lua_pcall(L, 0, LUA_MULTRET, 1);
388   lua_pushboolean(L, (status == 0));
389   lua_replace(L, 1);
390   return lua_gettop(L);  /* return status + all results */
391 }
392
393
394 static int luaB_tostring (lua_State *L) {
395   luaL_checkany(L, 1);
396   if (luaL_callmeta(L, 1, "__tostring"))  /* is there a metafield? */
397     return 1;  /* use its value */
398   switch (lua_type(L, 1)) {
399     case LUA_TNUMBER:
400       lua_pushstring(L, lua_tostring(L, 1));
401       break;
402     case LUA_TSTRING:
403       lua_pushvalue(L, 1);
404       break;
405     case LUA_TBOOLEAN:
406       lua_pushstring(L, (lua_toboolean(L, 1) ? "true" : "false"));
407       break;
408     case LUA_TNIL:
409       lua_pushliteral(L, "nil");
410       break;
411     default:
412       lua_pushfstring(L, "%s: %p", luaL_typename(L, 1), lua_topointer(L, 1));
413       break;
414   }
415   return 1;
416 }
417
418
419 static int luaB_newproxy (lua_State *L) {
420   lua_settop(L, 1);
421   lua_newuserdata(L, 0);  /* create proxy */
422   if (lua_toboolean(L, 1) == 0)
423     return 1;  /* no metatable */
424   else if (lua_isboolean(L, 1)) {
425     lua_newtable(L);  /* create a new metatable `m' ... */
426     lua_pushvalue(L, -1);  /* ... and mark `m' as a valid metatable */
427     lua_pushboolean(L, 1);
428     lua_rawset(L, lua_upvalueindex(1));  /* weaktable[m] = true */
429   }
430   else {
431     int validproxy = 0;  /* to check if weaktable[metatable(u)] == true */
432     if (lua_getmetatable(L, 1)) {
433       lua_rawget(L, lua_upvalueindex(1));
434       validproxy = lua_toboolean(L, -1);
435       lua_pop(L, 1);  /* remove value */
436     }
437     luaL_argcheck(L, validproxy, 1, "boolean or proxy expected");
438     lua_getmetatable(L, 1);  /* metatable is valid; get it */
439   }
440   lua_setmetatable(L, 2);
441   return 1;
442 }
443
444
445 static const luaL_Reg base_funcs[] = {
446   {"assert", luaB_assert},
447   {"collectgarbage", luaB_collectgarbage},
448   {"dofile", luaB_dofile},
449   {"error", luaB_error},
450   {"gcinfo", luaB_gcinfo},
451   {"getfenv", luaB_getfenv},
452   {"getmetatable", luaB_getmetatable},
453   {"loadfile", luaB_loadfile},
454   {"load", luaB_load},
455   {"loadstring", luaB_loadstring},
456   {"next", luaB_next},
457   {"pcall", luaB_pcall},
458   {"print", luaB_print},
459   {"rawequal", luaB_rawequal},
460   {"rawget", luaB_rawget},
461   {"rawset", luaB_rawset},
462   {"select", luaB_select},
463   {"setfenv", luaB_setfenv},
464   {"setmetatable", luaB_setmetatable},
465   {"tonumber", luaB_tonumber},
466   {"tostring", luaB_tostring},
467   {"type", luaB_type},
468   {"unpack", luaB_unpack},
469   {"xpcall", luaB_xpcall},
470   {NULL, NULL}
471 };
472
473
474 /*
475 ** {======================================================
476 ** Coroutine library
477 ** =======================================================
478 */
479
480 #define CO_RUN  0       /* running */
481 #define CO_SUS  1       /* suspended */
482 #define CO_NOR  2       /* 'normal' (it resumed another coroutine) */
483 #define CO_DEAD 3
484
485 static const char *const statnames[] =
486     {"running", "suspended", "normal", "dead"};
487
488 static int costatus (lua_State *L, lua_State *co) {
489   if (L == co) return CO_RUN;
490   switch (lua_status(co)) {
491     case LUA_YIELD:
492       return CO_SUS;
493     case 0: {
494       lua_Debug ar;
495       if (lua_getstack(co, 0, &ar) > 0)  /* does it have frames? */
496         return CO_NOR;  /* it is running */
497       else if (lua_gettop(co) == 0)
498           return CO_DEAD;
499       else
500         return CO_SUS;  /* initial state */
501     }
502     default:  /* some error occured */
503       return CO_DEAD;
504   }
505 }
506
507
508 static int luaB_costatus (lua_State *L) {
509   lua_State *co = lua_tothread(L, 1);
510   luaL_argcheck(L, co, 1, "coroutine expected");
511   lua_pushstring(L, statnames[costatus(L, co)]);
512   return 1;
513 }
514
515
516 static int auxresume (lua_State *L, lua_State *co, int narg) {
517   int status = costatus(L, co);
518   if (!lua_checkstack(co, narg))
519     luaL_error(L, "too many arguments to resume");
520   if (status != CO_SUS) {
521     lua_pushfstring(L, "cannot resume %s coroutine", statnames[status]);
522     return -1;  /* error flag */
523   }
524   lua_xmove(L, co, narg);
525   lua_setlevel(L, co);
526   status = lua_resume(co, narg);
527   if (status == 0 || status == LUA_YIELD) {
528     int nres = lua_gettop(co);
529     if (!lua_checkstack(L, nres))
530       luaL_error(L, "too many results to resume");
531     lua_xmove(co, L, nres);  /* move yielded values */
532     return nres;
533   }
534   else {
535     lua_xmove(co, L, 1);  /* move error message */
536     return -1;  /* error flag */
537   }
538 }
539
540
541 static int luaB_coresume (lua_State *L) {
542   lua_State *co = lua_tothread(L, 1);
543   int r;
544   luaL_argcheck(L, co, 1, "coroutine expected");
545   r = auxresume(L, co, lua_gettop(L) - 1);
546   if (r < 0) {
547     lua_pushboolean(L, 0);
548     lua_insert(L, -2);
549     return 2;  /* return false + error message */
550   }
551   else {
552     lua_pushboolean(L, 1);
553     lua_insert(L, -(r + 1));
554     return r + 1;  /* return true + `resume' returns */
555   }
556 }
557
558
559 static int luaB_auxwrap (lua_State *L) {
560   lua_State *co = lua_tothread(L, lua_upvalueindex(1));
561   int r = auxresume(L, co, lua_gettop(L));
562   if (r < 0) {
563     if (lua_isstring(L, -1)) {  /* error object is a string? */
564       luaL_where(L, 1);  /* add extra info */
565       lua_insert(L, -2);
566       lua_concat(L, 2);
567     }
568     lua_error(L);  /* propagate error */
569   }
570   return r;
571 }
572
573
574 static int luaB_cocreate (lua_State *L) {
575   lua_State *NL = lua_newthread(L);
576   luaL_argcheck(L, lua_isfunction(L, 1) && !lua_iscfunction(L, 1), 1,
577     "Lua function expected");
578   lua_pushvalue(L, 1);  /* move function to top */
579   lua_xmove(L, NL, 1);  /* move function from L to NL */
580   return 1;
581 }
582
583
584 static int luaB_cowrap (lua_State *L) {
585   luaB_cocreate(L);
586   lua_pushcclosure(L, luaB_auxwrap, 1);
587   return 1;
588 }
589
590
591 static int luaB_yield (lua_State *L) {
592   return lua_yield(L, lua_gettop(L));
593 }
594
595
596 static int luaB_corunning (lua_State *L) {
597   if (lua_pushthread(L))
598     lua_pushnil(L);  /* main thread is not a coroutine */
599   return 1;
600 }
601
602
603 static const luaL_Reg co_funcs[] = {
604   {"create", luaB_cocreate},
605   {"resume", luaB_coresume},
606   {"running", luaB_corunning},
607   {"status", luaB_costatus},
608   {"wrap", luaB_cowrap},
609   {"yield", luaB_yield},
610   {NULL, NULL}
611 };
612
613 /* }====================================================== */
614
615
616 static void auxopen (lua_State *L, const char *name,
617                      lua_CFunction f, lua_CFunction u) {
618   lua_pushcfunction(L, u);
619   lua_pushcclosure(L, f, 1);
620   lua_setfield(L, -2, name);
621 }
622
623
624 static void base_open (lua_State *L) {
625   /* set global _G */
626   lua_pushvalue(L, LUA_GLOBALSINDEX);
627   lua_setglobal(L, "_G");
628   /* open lib into global table */
629   luaL_register(L, "_G", base_funcs);
630   lua_pushliteral(L, LUA_VERSION);
631   lua_setglobal(L, "_VERSION");  /* set global _VERSION */
632   /* `ipairs' and `pairs' need auxliliary functions as upvalues */
633   auxopen(L, "ipairs", luaB_ipairs, ipairsaux);
634   auxopen(L, "pairs", luaB_pairs, luaB_next);
635   /* `newproxy' needs a weaktable as upvalue */
636   lua_createtable(L, 0, 1);  /* new table `w' */
637   lua_pushvalue(L, -1);  /* `w' will be its own metatable */
638   lua_setmetatable(L, -2);
639   lua_pushliteral(L, "kv");
640   lua_setfield(L, -2, "__mode");  /* metatable(w).__mode = "kv" */
641   lua_pushcclosure(L, luaB_newproxy, 1);
642   lua_setglobal(L, "newproxy");  /* set global `newproxy' */
643 }
644
645
646 LUALIB_API int luaopen_base (lua_State *L) {
647   base_open(L);
648   luaL_register(L, LUA_COLIBNAME, co_funcs);
649   return 2;
650 }
651
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