rlm@1: /*
rlm@1: ** $Id: lbaselib.c,v 1.191.1.6 2008/02/14 16:46:22 roberto Exp $
rlm@1: ** Basic library
rlm@1: ** See Copyright Notice in lua.h
rlm@1: */
rlm@1: 
rlm@1: 
rlm@1: 
rlm@1: #include <ctype.h>
rlm@1: #include <stdio.h>
rlm@1: #include <stdlib.h>
rlm@1: #include <string.h>
rlm@1: 
rlm@1: #define lbaselib_c
rlm@1: #define LUA_LIB
rlm@1: 
rlm@1: #include "lua.h"
rlm@1: 
rlm@1: #include "lauxlib.h"
rlm@1: #include "lualib.h"
rlm@1: 
rlm@1: 
rlm@1: 
rlm@1: 
rlm@1: /*
rlm@1: ** If your system does not support `stdout', you can just remove this function.
rlm@1: ** If you need, you can define your own `print' function, following this
rlm@1: ** model but changing `fputs' to put the strings at a proper place
rlm@1: ** (a console window or a log file, for instance).
rlm@1: */
rlm@1: static int luaB_print (lua_State *L) {
rlm@1:   int n = lua_gettop(L);  /* number of arguments */
rlm@1:   int i;
rlm@1:   lua_getglobal(L, "tostring");
rlm@1:   for (i=1; i<=n; i++) {
rlm@1:     const char *s;
rlm@1:     lua_pushvalue(L, -1);  /* function to be called */
rlm@1:     lua_pushvalue(L, i);   /* value to print */
rlm@1:     lua_call(L, 1, 1);
rlm@1:     s = lua_tostring(L, -1);  /* get result */
rlm@1:     if (s == NULL)
rlm@1:       return luaL_error(L, LUA_QL("tostring") " must return a string to "
rlm@1:                            LUA_QL("print"));
rlm@1:     if (i>1) fputs("\t", stdout);
rlm@1:     fputs(s, stdout);
rlm@1:     lua_pop(L, 1);  /* pop result */
rlm@1:   }
rlm@1:   fputs("\n", stdout);
rlm@1:   return 0;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_tonumber (lua_State *L) {
rlm@1:   int base = luaL_optint(L, 2, 10);
rlm@1:   if (base == 10) {  /* standard conversion */
rlm@1:     luaL_checkany(L, 1);
rlm@1:     if (lua_isnumber(L, 1)) {
rlm@1:       lua_pushnumber(L, lua_tonumber(L, 1));
rlm@1:       return 1;
rlm@1:     }
rlm@1:   }
rlm@1:   else {
rlm@1:     const char *s1 = luaL_checkstring(L, 1);
rlm@1:     char *s2;
rlm@1:     unsigned long n;
rlm@1:     luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range");
rlm@1:     n = strtoul(s1, &s2, base);
rlm@1:     if (s1 != s2) {  /* at least one valid digit? */
rlm@1:       while (isspace((unsigned char)(*s2))) s2++;  /* skip trailing spaces */
rlm@1:       if (*s2 == '\0') {  /* no invalid trailing characters? */
rlm@1:         lua_pushnumber(L, (lua_Number)n);
rlm@1:         return 1;
rlm@1:       }
rlm@1:     }
rlm@1:   }
rlm@1:   lua_pushnil(L);  /* else not a number */
rlm@1:   return 1;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_error (lua_State *L) {
rlm@1:   int level = luaL_optint(L, 2, 1);
rlm@1:   lua_settop(L, 1);
rlm@1:   if (lua_isstring(L, 1) && level > 0) {  /* add extra information? */
rlm@1:     luaL_where(L, level);
rlm@1:     lua_pushvalue(L, 1);
rlm@1:     lua_concat(L, 2);
rlm@1:   }
rlm@1:   return lua_error(L);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_getmetatable (lua_State *L) {
rlm@1:   luaL_checkany(L, 1);
rlm@1:   if (!lua_getmetatable(L, 1)) {
rlm@1:     lua_pushnil(L);
rlm@1:     return 1;  /* no metatable */
rlm@1:   }
rlm@1:   luaL_getmetafield(L, 1, "__metatable");
rlm@1:   return 1;  /* returns either __metatable field (if present) or metatable */
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_setmetatable (lua_State *L) {
rlm@1:   int t = lua_type(L, 2);
rlm@1:   luaL_checktype(L, 1, LUA_TTABLE);
rlm@1:   luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,
rlm@1:                     "nil or table expected");
rlm@1:   if (luaL_getmetafield(L, 1, "__metatable"))
rlm@1:     luaL_error(L, "cannot change a protected metatable");
rlm@1:   lua_settop(L, 2);
rlm@1:   lua_setmetatable(L, 1);
rlm@1:   return 1;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static void getfunc (lua_State *L, int opt) {
rlm@1:   if (lua_isfunction(L, 1)) lua_pushvalue(L, 1);
rlm@1:   else {
rlm@1:     lua_Debug ar;
rlm@1:     int level = opt ? luaL_optint(L, 1, 1) : luaL_checkint(L, 1);
rlm@1:     luaL_argcheck(L, level >= 0, 1, "level must be non-negative");
rlm@1:     if (lua_getstack(L, level, &ar) == 0)
rlm@1:       luaL_argerror(L, 1, "invalid level");
rlm@1:     lua_getinfo(L, "f", &ar);
rlm@1:     if (lua_isnil(L, -1))
rlm@1:       luaL_error(L, "no function environment for tail call at level %d",
rlm@1:                     level);
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_getfenv (lua_State *L) {
rlm@1:   getfunc(L, 1);
rlm@1:   if (lua_iscfunction(L, -1))  /* is a C function? */
rlm@1:     lua_pushvalue(L, LUA_GLOBALSINDEX);  /* return the thread's global env. */
rlm@1:   else
rlm@1:     lua_getfenv(L, -1);
rlm@1:   return 1;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_setfenv (lua_State *L) {
rlm@1:   luaL_checktype(L, 2, LUA_TTABLE);
rlm@1:   getfunc(L, 0);
rlm@1:   lua_pushvalue(L, 2);
rlm@1:   if (lua_isnumber(L, 1) && lua_tonumber(L, 1) == 0) {
rlm@1:     /* change environment of current thread */
rlm@1:     lua_pushthread(L);
rlm@1:     lua_insert(L, -2);
rlm@1:     lua_setfenv(L, -2);
rlm@1:     return 0;
rlm@1:   }
rlm@1:   else if (lua_iscfunction(L, -2) || lua_setfenv(L, -2) == 0)
rlm@1:     luaL_error(L,
rlm@1:           LUA_QL("setfenv") " cannot change environment of given object");
rlm@1:   return 1;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_rawequal (lua_State *L) {
rlm@1:   luaL_checkany(L, 1);
rlm@1:   luaL_checkany(L, 2);
rlm@1:   lua_pushboolean(L, lua_rawequal(L, 1, 2));
rlm@1:   return 1;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_rawget (lua_State *L) {
rlm@1:   luaL_checktype(L, 1, LUA_TTABLE);
rlm@1:   luaL_checkany(L, 2);
rlm@1:   lua_settop(L, 2);
rlm@1:   lua_rawget(L, 1);
rlm@1:   return 1;
rlm@1: }
rlm@1: 
rlm@1: static int luaB_rawset (lua_State *L) {
rlm@1:   luaL_checktype(L, 1, LUA_TTABLE);
rlm@1:   luaL_checkany(L, 2);
rlm@1:   luaL_checkany(L, 3);
rlm@1:   lua_settop(L, 3);
rlm@1:   lua_rawset(L, 1);
rlm@1:   return 1;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_gcinfo (lua_State *L) {
rlm@1:   lua_pushinteger(L, lua_getgccount(L));
rlm@1:   return 1;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_collectgarbage (lua_State *L) {
rlm@1:   static const char *const opts[] = {"stop", "restart", "collect",
rlm@1:     "count", "step", "setpause", "setstepmul", NULL};
rlm@1:   static const int optsnum[] = {LUA_GCSTOP, LUA_GCRESTART, LUA_GCCOLLECT,
rlm@1:     LUA_GCCOUNT, LUA_GCSTEP, LUA_GCSETPAUSE, LUA_GCSETSTEPMUL};
rlm@1:   int o = luaL_checkoption(L, 1, "collect", opts);
rlm@1:   int ex = luaL_optint(L, 2, 0);
rlm@1:   int res = lua_gc(L, optsnum[o], ex);
rlm@1:   switch (optsnum[o]) {
rlm@1:     case LUA_GCCOUNT: {
rlm@1:       int b = lua_gc(L, LUA_GCCOUNTB, 0);
rlm@1:       lua_pushnumber(L, res + ((lua_Number)b/1024));
rlm@1:       return 1;
rlm@1:     }
rlm@1:     case LUA_GCSTEP: {
rlm@1:       lua_pushboolean(L, res);
rlm@1:       return 1;
rlm@1:     }
rlm@1:     default: {
rlm@1:       lua_pushnumber(L, res);
rlm@1:       return 1;
rlm@1:     }
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_type (lua_State *L) {
rlm@1:   luaL_checkany(L, 1);
rlm@1:   lua_pushstring(L, luaL_typename(L, 1));
rlm@1:   return 1;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_next (lua_State *L) {
rlm@1:   luaL_checktype(L, 1, LUA_TTABLE);
rlm@1:   lua_settop(L, 2);  /* create a 2nd argument if there isn't one */
rlm@1:   if (lua_next(L, 1))
rlm@1:     return 2;
rlm@1:   else {
rlm@1:     lua_pushnil(L);
rlm@1:     return 1;
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_pairs (lua_State *L) {
rlm@1:   luaL_checktype(L, 1, LUA_TTABLE);
rlm@1:   lua_pushvalue(L, lua_upvalueindex(1));  /* return generator, */
rlm@1:   lua_pushvalue(L, 1);  /* state, */
rlm@1:   lua_pushnil(L);  /* and initial value */
rlm@1:   return 3;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int ipairsaux (lua_State *L) {
rlm@1:   int i = luaL_checkint(L, 2);
rlm@1:   luaL_checktype(L, 1, LUA_TTABLE);
rlm@1:   i++;  /* next value */
rlm@1:   lua_pushinteger(L, i);
rlm@1:   lua_rawgeti(L, 1, i);
rlm@1:   return (lua_isnil(L, -1)) ? 0 : 2;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_ipairs (lua_State *L) {
rlm@1:   luaL_checktype(L, 1, LUA_TTABLE);
rlm@1:   lua_pushvalue(L, lua_upvalueindex(1));  /* return generator, */
rlm@1:   lua_pushvalue(L, 1);  /* state, */
rlm@1:   lua_pushinteger(L, 0);  /* and initial value */
rlm@1:   return 3;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int load_aux (lua_State *L, int status) {
rlm@1:   if (status == 0)  /* OK? */
rlm@1:     return 1;
rlm@1:   else {
rlm@1:     lua_pushnil(L);
rlm@1:     lua_insert(L, -2);  /* put before error message */
rlm@1:     return 2;  /* return nil plus error message */
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_loadstring (lua_State *L) {
rlm@1:   size_t l;
rlm@1:   const char *s = luaL_checklstring(L, 1, &l);
rlm@1:   const char *chunkname = luaL_optstring(L, 2, s);
rlm@1:   return load_aux(L, luaL_loadbuffer(L, s, l, chunkname));
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_loadfile (lua_State *L) {
rlm@1:   const char *fname = luaL_optstring(L, 1, NULL);
rlm@1:   return load_aux(L, luaL_loadfile(L, fname));
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: /*
rlm@1: ** Reader for generic `load' function: `lua_load' uses the
rlm@1: ** stack for internal stuff, so the reader cannot change the
rlm@1: ** stack top. Instead, it keeps its resulting string in a
rlm@1: ** reserved slot inside the stack.
rlm@1: */
rlm@1: static const char *generic_reader (lua_State *L, void *ud, size_t *size) {
rlm@1:   (void)ud;  /* to avoid warnings */
rlm@1:   luaL_checkstack(L, 2, "too many nested functions");
rlm@1:   lua_pushvalue(L, 1);  /* get function */
rlm@1:   lua_call(L, 0, 1);  /* call it */
rlm@1:   if (lua_isnil(L, -1)) {
rlm@1:     *size = 0;
rlm@1:     return NULL;
rlm@1:   }
rlm@1:   else if (lua_isstring(L, -1)) {
rlm@1:     lua_replace(L, 3);  /* save string in a reserved stack slot */
rlm@1:     return lua_tolstring(L, 3, size);
rlm@1:   }
rlm@1:   else luaL_error(L, "reader function must return a string");
rlm@1:   return NULL;  /* to avoid warnings */
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_load (lua_State *L) {
rlm@1:   int status;
rlm@1:   const char *cname = luaL_optstring(L, 2, "=(load)");
rlm@1:   luaL_checktype(L, 1, LUA_TFUNCTION);
rlm@1:   lua_settop(L, 3);  /* function, eventual name, plus one reserved slot */
rlm@1:   status = lua_load(L, generic_reader, NULL, cname);
rlm@1:   return load_aux(L, status);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_dofile (lua_State *L) {
rlm@1:   const char *fname = luaL_optstring(L, 1, NULL);
rlm@1:   int n = lua_gettop(L);
rlm@1:   if (luaL_loadfile(L, fname) != 0) lua_error(L);
rlm@1:   lua_call(L, 0, LUA_MULTRET);
rlm@1:   return lua_gettop(L) - n;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_assert (lua_State *L) {
rlm@1:   luaL_checkany(L, 1);
rlm@1:   if (!lua_toboolean(L, 1))
rlm@1:     return luaL_error(L, "%s", luaL_optstring(L, 2, "assertion failed!"));
rlm@1:   return lua_gettop(L);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_unpack (lua_State *L) {
rlm@1:   int i, e, n;
rlm@1:   luaL_checktype(L, 1, LUA_TTABLE);
rlm@1:   i = luaL_optint(L, 2, 1);
rlm@1:   e = luaL_opt(L, luaL_checkint, 3, luaL_getn(L, 1));
rlm@1:   if (i > e) return 0;  /* empty range */
rlm@1:   n = e - i + 1;  /* number of elements */
rlm@1:   if (n <= 0 || !lua_checkstack(L, n))  /* n <= 0 means arith. overflow */
rlm@1:     return luaL_error(L, "too many results to unpack");
rlm@1:   lua_rawgeti(L, 1, i);  /* push arg[i] (avoiding overflow problems) */
rlm@1:   while (i++ < e)  /* push arg[i + 1...e] */
rlm@1:     lua_rawgeti(L, 1, i);
rlm@1:   return n;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_select (lua_State *L) {
rlm@1:   int n = lua_gettop(L);
rlm@1:   if (lua_type(L, 1) == LUA_TSTRING && *lua_tostring(L, 1) == '#') {
rlm@1:     lua_pushinteger(L, n-1);
rlm@1:     return 1;
rlm@1:   }
rlm@1:   else {
rlm@1:     int i = luaL_checkint(L, 1);
rlm@1:     if (i < 0) i = n + i;
rlm@1:     else if (i > n) i = n;
rlm@1:     luaL_argcheck(L, 1 <= i, 1, "index out of range");
rlm@1:     return n - i;
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_pcall (lua_State *L) {
rlm@1:   int status;
rlm@1:   luaL_checkany(L, 1);
rlm@1:   status = lua_pcall(L, lua_gettop(L) - 1, LUA_MULTRET, 0);
rlm@1:   lua_pushboolean(L, (status == 0));
rlm@1:   lua_insert(L, 1);
rlm@1:   return lua_gettop(L);  /* return status + all results */
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_xpcall (lua_State *L) {
rlm@1:   int status;
rlm@1:   luaL_checkany(L, 2);
rlm@1:   lua_settop(L, 2);
rlm@1:   lua_insert(L, 1);  /* put error function under function to be called */
rlm@1:   status = lua_pcall(L, 0, LUA_MULTRET, 1);
rlm@1:   lua_pushboolean(L, (status == 0));
rlm@1:   lua_replace(L, 1);
rlm@1:   return lua_gettop(L);  /* return status + all results */
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_tostring (lua_State *L) {
rlm@1:   luaL_checkany(L, 1);
rlm@1:   if (luaL_callmeta(L, 1, "__tostring"))  /* is there a metafield? */
rlm@1:     return 1;  /* use its value */
rlm@1:   switch (lua_type(L, 1)) {
rlm@1:     case LUA_TNUMBER:
rlm@1:       lua_pushstring(L, lua_tostring(L, 1));
rlm@1:       break;
rlm@1:     case LUA_TSTRING:
rlm@1:       lua_pushvalue(L, 1);
rlm@1:       break;
rlm@1:     case LUA_TBOOLEAN:
rlm@1:       lua_pushstring(L, (lua_toboolean(L, 1) ? "true" : "false"));
rlm@1:       break;
rlm@1:     case LUA_TNIL:
rlm@1:       lua_pushliteral(L, "nil");
rlm@1:       break;
rlm@1:     default:
rlm@1:       lua_pushfstring(L, "%s: %p", luaL_typename(L, 1), lua_topointer(L, 1));
rlm@1:       break;
rlm@1:   }
rlm@1:   return 1;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_newproxy (lua_State *L) {
rlm@1:   lua_settop(L, 1);
rlm@1:   lua_newuserdata(L, 0);  /* create proxy */
rlm@1:   if (lua_toboolean(L, 1) == 0)
rlm@1:     return 1;  /* no metatable */
rlm@1:   else if (lua_isboolean(L, 1)) {
rlm@1:     lua_newtable(L);  /* create a new metatable `m' ... */
rlm@1:     lua_pushvalue(L, -1);  /* ... and mark `m' as a valid metatable */
rlm@1:     lua_pushboolean(L, 1);
rlm@1:     lua_rawset(L, lua_upvalueindex(1));  /* weaktable[m] = true */
rlm@1:   }
rlm@1:   else {
rlm@1:     int validproxy = 0;  /* to check if weaktable[metatable(u)] == true */
rlm@1:     if (lua_getmetatable(L, 1)) {
rlm@1:       lua_rawget(L, lua_upvalueindex(1));
rlm@1:       validproxy = lua_toboolean(L, -1);
rlm@1:       lua_pop(L, 1);  /* remove value */
rlm@1:     }
rlm@1:     luaL_argcheck(L, validproxy, 1, "boolean or proxy expected");
rlm@1:     lua_getmetatable(L, 1);  /* metatable is valid; get it */
rlm@1:   }
rlm@1:   lua_setmetatable(L, 2);
rlm@1:   return 1;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static const luaL_Reg base_funcs[] = {
rlm@1:   {"assert", luaB_assert},
rlm@1:   {"collectgarbage", luaB_collectgarbage},
rlm@1:   {"dofile", luaB_dofile},
rlm@1:   {"error", luaB_error},
rlm@1:   {"gcinfo", luaB_gcinfo},
rlm@1:   {"getfenv", luaB_getfenv},
rlm@1:   {"getmetatable", luaB_getmetatable},
rlm@1:   {"loadfile", luaB_loadfile},
rlm@1:   {"load", luaB_load},
rlm@1:   {"loadstring", luaB_loadstring},
rlm@1:   {"next", luaB_next},
rlm@1:   {"pcall", luaB_pcall},
rlm@1:   {"print", luaB_print},
rlm@1:   {"rawequal", luaB_rawequal},
rlm@1:   {"rawget", luaB_rawget},
rlm@1:   {"rawset", luaB_rawset},
rlm@1:   {"select", luaB_select},
rlm@1:   {"setfenv", luaB_setfenv},
rlm@1:   {"setmetatable", luaB_setmetatable},
rlm@1:   {"tonumber", luaB_tonumber},
rlm@1:   {"tostring", luaB_tostring},
rlm@1:   {"type", luaB_type},
rlm@1:   {"unpack", luaB_unpack},
rlm@1:   {"xpcall", luaB_xpcall},
rlm@1:   {NULL, NULL}
rlm@1: };
rlm@1: 
rlm@1: 
rlm@1: /*
rlm@1: ** {======================================================
rlm@1: ** Coroutine library
rlm@1: ** =======================================================
rlm@1: */
rlm@1: 
rlm@1: #define CO_RUN	0	/* running */
rlm@1: #define CO_SUS	1	/* suspended */
rlm@1: #define CO_NOR	2	/* 'normal' (it resumed another coroutine) */
rlm@1: #define CO_DEAD	3
rlm@1: 
rlm@1: static const char *const statnames[] =
rlm@1:     {"running", "suspended", "normal", "dead"};
rlm@1: 
rlm@1: static int costatus (lua_State *L, lua_State *co) {
rlm@1:   if (L == co) return CO_RUN;
rlm@1:   switch (lua_status(co)) {
rlm@1:     case LUA_YIELD:
rlm@1:       return CO_SUS;
rlm@1:     case 0: {
rlm@1:       lua_Debug ar;
rlm@1:       if (lua_getstack(co, 0, &ar) > 0)  /* does it have frames? */
rlm@1:         return CO_NOR;  /* it is running */
rlm@1:       else if (lua_gettop(co) == 0)
rlm@1:           return CO_DEAD;
rlm@1:       else
rlm@1:         return CO_SUS;  /* initial state */
rlm@1:     }
rlm@1:     default:  /* some error occured */
rlm@1:       return CO_DEAD;
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_costatus (lua_State *L) {
rlm@1:   lua_State *co = lua_tothread(L, 1);
rlm@1:   luaL_argcheck(L, co, 1, "coroutine expected");
rlm@1:   lua_pushstring(L, statnames[costatus(L, co)]);
rlm@1:   return 1;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int auxresume (lua_State *L, lua_State *co, int narg) {
rlm@1:   int status = costatus(L, co);
rlm@1:   if (!lua_checkstack(co, narg))
rlm@1:     luaL_error(L, "too many arguments to resume");
rlm@1:   if (status != CO_SUS) {
rlm@1:     lua_pushfstring(L, "cannot resume %s coroutine", statnames[status]);
rlm@1:     return -1;  /* error flag */
rlm@1:   }
rlm@1:   lua_xmove(L, co, narg);
rlm@1:   lua_setlevel(L, co);
rlm@1:   status = lua_resume(co, narg);
rlm@1:   if (status == 0 || status == LUA_YIELD) {
rlm@1:     int nres = lua_gettop(co);
rlm@1:     if (!lua_checkstack(L, nres + 1))
rlm@1:       luaL_error(L, "too many results to resume");
rlm@1:     lua_xmove(co, L, nres);  /* move yielded values */
rlm@1:     return nres;
rlm@1:   }
rlm@1:   else {
rlm@1:     lua_xmove(co, L, 1);  /* move error message */
rlm@1:     return -1;  /* error flag */
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_coresume (lua_State *L) {
rlm@1:   lua_State *co = lua_tothread(L, 1);
rlm@1:   int r;
rlm@1:   luaL_argcheck(L, co, 1, "coroutine expected");
rlm@1:   r = auxresume(L, co, lua_gettop(L) - 1);
rlm@1:   if (r < 0) {
rlm@1:     lua_pushboolean(L, 0);
rlm@1:     lua_insert(L, -2);
rlm@1:     return 2;  /* return false + error message */
rlm@1:   }
rlm@1:   else {
rlm@1:     lua_pushboolean(L, 1);
rlm@1:     lua_insert(L, -(r + 1));
rlm@1:     return r + 1;  /* return true + `resume' returns */
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_auxwrap (lua_State *L) {
rlm@1:   lua_State *co = lua_tothread(L, lua_upvalueindex(1));
rlm@1:   int r = auxresume(L, co, lua_gettop(L));
rlm@1:   if (r < 0) {
rlm@1:     if (lua_isstring(L, -1)) {  /* error object is a string? */
rlm@1:       luaL_where(L, 1);  /* add extra info */
rlm@1:       lua_insert(L, -2);
rlm@1:       lua_concat(L, 2);
rlm@1:     }
rlm@1:     lua_error(L);  /* propagate error */
rlm@1:   }
rlm@1:   return r;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_cocreate (lua_State *L) {
rlm@1:   lua_State *NL = lua_newthread(L);
rlm@1:   luaL_argcheck(L, lua_isfunction(L, 1) && !lua_iscfunction(L, 1), 1,
rlm@1:     "Lua function expected");
rlm@1:   lua_pushvalue(L, 1);  /* move function to top */
rlm@1:   lua_xmove(L, NL, 1);  /* move function from L to NL */
rlm@1:   return 1;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_cowrap (lua_State *L) {
rlm@1:   luaB_cocreate(L);
rlm@1:   lua_pushcclosure(L, luaB_auxwrap, 1);
rlm@1:   return 1;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_yield (lua_State *L) {
rlm@1:   return lua_yield(L, lua_gettop(L));
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static int luaB_corunning (lua_State *L) {
rlm@1:   if (lua_pushthread(L))
rlm@1:     lua_pushnil(L);  /* main thread is not a coroutine */
rlm@1:   return 1;
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static const luaL_Reg co_funcs[] = {
rlm@1:   {"create", luaB_cocreate},
rlm@1:   {"resume", luaB_coresume},
rlm@1:   {"running", luaB_corunning},
rlm@1:   {"status", luaB_costatus},
rlm@1:   {"wrap", luaB_cowrap},
rlm@1:   {"yield", luaB_yield},
rlm@1:   {NULL, NULL}
rlm@1: };
rlm@1: 
rlm@1: /* }====================================================== */
rlm@1: 
rlm@1: 
rlm@1: static void auxopen (lua_State *L, const char *name,
rlm@1:                      lua_CFunction f, lua_CFunction u) {
rlm@1:   lua_pushcfunction(L, u);
rlm@1:   lua_pushcclosure(L, f, 1);
rlm@1:   lua_setfield(L, -2, name);
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: static void base_open (lua_State *L) {
rlm@1:   /* set global _G */
rlm@1:   lua_pushvalue(L, LUA_GLOBALSINDEX);
rlm@1:   lua_setglobal(L, "_G");
rlm@1:   /* open lib into global table */
rlm@1:   luaL_register(L, "_G", base_funcs);
rlm@1:   lua_pushliteral(L, LUA_VERSION);
rlm@1:   lua_setglobal(L, "_VERSION");  /* set global _VERSION */
rlm@1:   /* `ipairs' and `pairs' need auxliliary functions as upvalues */
rlm@1:   auxopen(L, "ipairs", luaB_ipairs, ipairsaux);
rlm@1:   auxopen(L, "pairs", luaB_pairs, luaB_next);
rlm@1:   /* `newproxy' needs a weaktable as upvalue */
rlm@1:   lua_createtable(L, 0, 1);  /* new table `w' */
rlm@1:   lua_pushvalue(L, -1);  /* `w' will be its own metatable */
rlm@1:   lua_setmetatable(L, -2);
rlm@1:   lua_pushliteral(L, "kv");
rlm@1:   lua_setfield(L, -2, "__mode");  /* metatable(w).__mode = "kv" */
rlm@1:   lua_pushcclosure(L, luaB_newproxy, 1);
rlm@1:   lua_setglobal(L, "newproxy");  /* set global `newproxy' */
rlm@1: }
rlm@1: 
rlm@1: 
rlm@1: LUALIB_API int luaopen_base (lua_State *L) {
rlm@1:   base_open(L);
rlm@1:   luaL_register(L, LUA_COLIBNAME, co_funcs);
rlm@1:   return 2;
rlm@1: }
rlm@1: