src/lbaselib.c

   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