1 /*
2 ** $Id: lbaselib.c,v 1.191.1.6 2008/02/14 16:46:22 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 */
luaB_print(lua_State * L)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 
luaB_tonumber(lua_State * L)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 
luaB_error(lua_State * L)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 
luaB_getmetatable(lua_State * L)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 
luaB_setmetatable(lua_State * L)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 
getfunc(lua_State * L,int opt)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 
luaB_getfenv(lua_State * L)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 
luaB_setfenv(lua_State * L)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 
luaB_rawequal(lua_State * L)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 
luaB_rawget(lua_State * L)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 
luaB_rawset(lua_State * L)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 
luaB_gcinfo(lua_State * L)187 static int luaB_gcinfo (lua_State *L) {
188   lua_pushinteger(L, lua_getgccount(L));
189   return 1;
190 }
191 
192 
luaB_collectgarbage(lua_State * L)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 
luaB_type(lua_State * L)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 
luaB_next(lua_State * L)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 
luaB_pairs(lua_State * L)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 
ipairsaux(lua_State * L)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 
luaB_ipairs(lua_State * L)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 
load_aux(lua_State * L,int status)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 
luaB_loadstring(lua_State * L)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 
luaB_loadfile(lua_State * L)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 */
generic_reader(lua_State * L,void * ud,size_t * size)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 
luaB_load(lua_State * L)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 
luaB_dofile(lua_State * L)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 
luaB_assert(lua_State * L)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 
luaB_unpack(lua_State * L)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   if (i > e) return 0;  /* empty range */
348   n = e - i + 1;  /* number of elements */
349   if (n <= 0 || !lua_checkstack(L, n))  /* n <= 0 means arith. overflow */
350     return luaL_error(L, "too many results to unpack");
351   lua_rawgeti(L, 1, i);  /* push arg[i] (avoiding overflow problems) */
352   while (i++ < e)  /* push arg[i + 1...e] */
353     lua_rawgeti(L, 1, i);
354   return n;
355 }
356 
357 
luaB_select(lua_State * L)358 static int luaB_select (lua_State *L) {
359   int n = lua_gettop(L);
360   if (lua_type(L, 1) == LUA_TSTRING && *lua_tostring(L, 1) == '#') {
361     lua_pushinteger(L, n-1);
362     return 1;
363   }
364   else {
365     int i = luaL_checkint(L, 1);
366     if (i < 0) i = n + i;
367     else if (i > n) i = n;
368     luaL_argcheck(L, 1 <= i, 1, "index out of range");
369     return n - i;
370   }
371 }
372 
373 
luaB_pcall(lua_State * L)374 static int luaB_pcall (lua_State *L) {
375   int status;
376   luaL_checkany(L, 1);
377   status = lua_pcall(L, lua_gettop(L) - 1, LUA_MULTRET, 0);
378   lua_pushboolean(L, (status == 0));
379   lua_insert(L, 1);
380   return lua_gettop(L);  /* return status + all results */
381 }
382 
383 
luaB_xpcall(lua_State * L)384 static int luaB_xpcall (lua_State *L) {
385   int status;
386   luaL_checkany(L, 2);
387   lua_settop(L, 2);
388   lua_insert(L, 1);  /* put error function under function to be called */
389   status = lua_pcall(L, 0, LUA_MULTRET, 1);
390   lua_pushboolean(L, (status == 0));
391   lua_replace(L, 1);
392   return lua_gettop(L);  /* return status + all results */
393 }
394 
395 
luaB_tostring(lua_State * L)396 static int luaB_tostring (lua_State *L) {
397   luaL_checkany(L, 1);
398   if (luaL_callmeta(L, 1, "__tostring"))  /* is there a metafield? */
399     return 1;  /* use its value */
400   switch (lua_type(L, 1)) {
401     case LUA_TNUMBER:
402       lua_pushstring(L, lua_tostring(L, 1));
403       break;
404     case LUA_TSTRING:
405       lua_pushvalue(L, 1);
406       break;
407     case LUA_TBOOLEAN:
408       lua_pushstring(L, (lua_toboolean(L, 1) ? "true" : "false"));
409       break;
410     case LUA_TNIL:
411       lua_pushliteral(L, "nil");
412       break;
413     /*
414      * SPRING - synced safety change
415      */
416     case LUA_TNONE:          { lua_pushliteral(L, "<none>");          break; }
417     case LUA_TTABLE:         { lua_pushliteral(L, "<table>");         break; }
418     case LUA_TUSERDATA:      { lua_pushliteral(L, "<userdata>");      break; }
419     case LUA_TLIGHTUSERDATA: { lua_pushliteral(L, "<lightuserdata>"); break; }
420     case LUA_TFUNCTION:      { lua_pushliteral(L, "<function>");      break; }
421     case LUA_TTHREAD:        { lua_pushliteral(L, "<thread>");        break; }
422     default:                 { lua_pushliteral(L, "<unknown_type>");  break; }
423 /*
424     default:
425       lua_pushfstring(L, "%s: %p", luaL_typename(L, 1), lua_topointer(L, 1));
426       break;
427 */
428   }
429   return 1;
430 }
431 
432 
luaB_newproxy(lua_State * L)433 static int luaB_newproxy (lua_State *L) {
434   lua_settop(L, 1);
435   lua_newuserdata(L, 0);  /* create proxy */
436   if (lua_toboolean(L, 1) == 0)
437     return 1;  /* no metatable */
438   else if (lua_isboolean(L, 1)) {
439     lua_newtable(L);  /* create a new metatable `m' ... */
440     lua_pushvalue(L, -1);  /* ... and mark `m' as a valid metatable */
441     lua_pushboolean(L, 1);
442     lua_rawset(L, lua_upvalueindex(1));  /* weaktable[m] = true */
443   }
444   else {
445     int validproxy = 0;  /* to check if weaktable[metatable(u)] == true */
446     if (lua_getmetatable(L, 1)) {
447       lua_rawget(L, lua_upvalueindex(1));
448       validproxy = lua_toboolean(L, -1);
449       lua_pop(L, 1);  /* remove value */
450     }
451     luaL_argcheck(L, validproxy, 1, "boolean or proxy expected");
452     lua_getmetatable(L, 1);  /* metatable is valid; get it */
453   }
454   lua_setmetatable(L, 2);
455   return 1;
456 }
457 
458 
459 static const luaL_Reg base_funcs[] = {
460   {"assert", luaB_assert},
461   {"collectgarbage", luaB_collectgarbage},
462   {"dofile", luaB_dofile},
463   {"error", luaB_error},
464   {"gcinfo", luaB_gcinfo},
465   {"getfenv", luaB_getfenv},
466   {"getmetatable", luaB_getmetatable},
467   {"loadfile", luaB_loadfile},
468   {"load", luaB_load},
469   {"loadstring", luaB_loadstring},
470   {"next", luaB_next},
471   {"pcall", luaB_pcall},
472   {"print", luaB_print},
473   {"rawequal", luaB_rawequal},
474   {"rawget", luaB_rawget},
475   {"rawset", luaB_rawset},
476   {"select", luaB_select},
477   {"setfenv", luaB_setfenv},
478   {"setmetatable", luaB_setmetatable},
479   {"tonumber", luaB_tonumber},
480   {"tostring", luaB_tostring},
481   {"type", luaB_type},
482   {"unpack", luaB_unpack},
483   {"xpcall", luaB_xpcall},
484   {NULL, NULL}
485 };
486 
487 
488 /*
489 ** {======================================================
490 ** Coroutine library
491 ** =======================================================
492 */
493 
494 #define CO_RUN	0	/* running */
495 #define CO_SUS	1	/* suspended */
496 #define CO_NOR	2	/* 'normal' (it resumed another coroutine) */
497 #define CO_DEAD	3
498 
499 static const char *const statnames[] =
500     {"running", "suspended", "normal", "dead"};
501 
costatus(lua_State * L,lua_State * co)502 static int costatus (lua_State *L, lua_State *co) {
503   if (L == co) return CO_RUN;
504   switch (lua_status(co)) {
505     case LUA_YIELD:
506       return CO_SUS;
507     case 0: {
508       lua_Debug ar;
509       if (lua_getstack(co, 0, &ar) > 0)  /* does it have frames? */
510         return CO_NOR;  /* it is running */
511       else if (lua_gettop(co) == 0)
512           return CO_DEAD;
513       else
514         return CO_SUS;  /* initial state */
515     }
516     default:  /* some error occured */
517       return CO_DEAD;
518   }
519 }
520 
521 
luaB_costatus(lua_State * L)522 static int luaB_costatus (lua_State *L) {
523   lua_State *co = lua_tothread(L, 1);
524   luaL_argcheck(L, co, 1, "coroutine expected");
525   lua_pushstring(L, statnames[costatus(L, co)]);
526   return 1;
527 }
528 
529 
auxresume(lua_State * L,lua_State * co,int narg)530 static int auxresume (lua_State *L, lua_State *co, int narg) {
531   int status = costatus(L, co);
532   if (!lua_checkstack(co, narg))
533     luaL_error(L, "too many arguments to resume");
534   if (status != CO_SUS) {
535     lua_pushfstring(L, "cannot resume %s coroutine", statnames[status]);
536     return -1;  /* error flag */
537   }
538   lua_xmove(L, co, narg);
539   lua_setlevel(L, co);
540   status = lua_resume(co, narg);
541   if (status == 0 || status == LUA_YIELD) {
542     int nres = lua_gettop(co);
543     if (!lua_checkstack(L, nres + 1))
544       luaL_error(L, "too many results to resume");
545     lua_xmove(co, L, nres);  /* move yielded values */
546     return nres;
547   }
548   else {
549     lua_xmove(co, L, 1);  /* move error message */
550     return -1;  /* error flag */
551   }
552 }
553 
554 
luaB_coresume(lua_State * L)555 static int luaB_coresume (lua_State *L) {
556   lua_State *co = lua_tothread(L, 1);
557   int r;
558   luaL_argcheck(L, co, 1, "coroutine expected");
559   r = auxresume(L, co, lua_gettop(L) - 1);
560   if (r < 0) {
561     lua_pushboolean(L, 0);
562     lua_insert(L, -2);
563     return 2;  /* return false + error message */
564   }
565   else {
566     lua_pushboolean(L, 1);
567     lua_insert(L, -(r + 1));
568     return r + 1;  /* return true + `resume' returns */
569   }
570 }
571 
572 
luaB_auxwrap(lua_State * L)573 static int luaB_auxwrap (lua_State *L) {
574   lua_State *co = lua_tothread(L, lua_upvalueindex(1));
575   int r = auxresume(L, co, lua_gettop(L));
576   if (r < 0) {
577     if (lua_isstring(L, -1)) {  /* error object is a string? */
578       luaL_where(L, 1);  /* add extra info */
579       lua_insert(L, -2);
580       lua_concat(L, 2);
581     }
582     lua_error(L);  /* propagate error */
583   }
584   return r;
585 }
586 
587 
luaB_cocreate(lua_State * L)588 static int luaB_cocreate (lua_State *L) {
589   lua_State *NL = lua_newthread(L);
590   luaL_argcheck(L, lua_isfunction(L, 1) && !lua_iscfunction(L, 1), 1,
591     "Lua function expected");
592   lua_pushvalue(L, 1);  /* move function to top */
593   lua_xmove(L, NL, 1);  /* move function from L to NL */
594   return 1;
595 }
596 
597 
luaB_cowrap(lua_State * L)598 static int luaB_cowrap (lua_State *L) {
599   luaB_cocreate(L);
600   lua_pushcclosure(L, luaB_auxwrap, 1);
601   return 1;
602 }
603 
604 
luaB_yield(lua_State * L)605 static int luaB_yield (lua_State *L) {
606   return lua_yield(L, lua_gettop(L));
607 }
608 
609 
luaB_corunning(lua_State * L)610 static int luaB_corunning (lua_State *L) {
611   if (lua_pushthread(L))
612     lua_pushnil(L);  /* main thread is not a coroutine */
613   return 1;
614 }
615 
616 
617 static const luaL_Reg co_funcs[] = {
618   {"create", luaB_cocreate},
619   {"resume", luaB_coresume},
620   {"running", luaB_corunning},
621   {"status", luaB_costatus},
622   {"wrap", luaB_cowrap},
623   {"yield", luaB_yield},
624   {NULL, NULL}
625 };
626 
627 /* }====================================================== */
628 
629 
auxopen(lua_State * L,const char * name,lua_CFunction f,lua_CFunction u)630 static void auxopen (lua_State *L, const char *name,
631                      lua_CFunction f, lua_CFunction u) {
632   lua_pushcfunction(L, u);
633   lua_pushcclosure(L, f, 1);
634   lua_setfield(L, -2, name);
635 }
636 
637 
base_open(lua_State * L)638 static void base_open (lua_State *L) {
639   /* set global _G */
640   lua_pushvalue(L, LUA_GLOBALSINDEX);
641   lua_setglobal(L, "_G");
642   /* open lib into global table */
643   luaL_register(L, "_G", base_funcs);
644   lua_pushliteral(L, LUA_VERSION);
645   lua_setglobal(L, "_VERSION");  /* set global _VERSION */
646   /* `ipairs' and `pairs' need auxiliary functions as upvalues */
647   auxopen(L, "ipairs", luaB_ipairs, ipairsaux);
648   auxopen(L, "pairs", luaB_pairs, luaB_next);
649   /* `newproxy' needs a weaktable as upvalue */
650   lua_createtable(L, 0, 1);  /* new table `w' */
651   lua_pushvalue(L, -1);  /* `w' will be its own metatable */
652   lua_setmetatable(L, -2);
653   lua_pushliteral(L, "kv");
654   lua_setfield(L, -2, "__mode");  /* metatable(w).__mode = "kv" */
655   lua_pushcclosure(L, luaB_newproxy, 1);
656   lua_setglobal(L, "newproxy");  /* set global `newproxy' */
657 }
658 
659 
luaopen_base(lua_State * L)660 LUALIB_API int luaopen_base (lua_State *L) {
661   base_open(L);
662   luaL_register(L, LUA_COLIBNAME, co_funcs);
663   return 2;
664 }
665 
666