lua/lbaselib.c
2011-01-26 14:30:02 -02:00

485 lines
13 KiB
C

/*
** $Id: lbaselib.c,v 1.258 2011/01/07 12:41:48 roberto Exp roberto $
** Basic library
** See Copyright Notice in lua.h
*/
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define lbaselib_c
#define LUA_LIB
#include "lua.h"
#include "lauxlib.h"
#include "lualib.h"
static int luaB_print (lua_State *L) {
int n = lua_gettop(L); /* number of arguments */
int i;
lua_getglobal(L, "tostring");
for (i=1; i<=n; i++) {
const char *s;
size_t l;
lua_pushvalue(L, -1); /* function to be called */
lua_pushvalue(L, i); /* value to print */
lua_call(L, 1, 1);
s = lua_tolstring(L, -1, &l); /* get result */
if (s == NULL)
return luaL_error(L, LUA_QL("tostring") " must return a string to "
LUA_QL("print"));
if (i>1) luai_writestring("\t", 1);
luai_writestring(s, l);
lua_pop(L, 1); /* pop result */
}
luai_writestring("\n", 1);
return 0;
}
#define SPACECHARS " \f\n\r\t\v"
static int luaB_tonumber (lua_State *L) {
int base = luaL_optint(L, 2, 10);
luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range");
if (base == 10) { /* standard conversion */
luaL_checkany(L, 1);
if (lua_isnumber(L, 1)) {
lua_pushnumber(L, lua_tonumber(L, 1));
return 1;
} /* else not a number */
}
else {
size_t l;
const char *s = luaL_checklstring(L, 1, &l);
const char *e = s + l; /* end point for 's' */
int neg = 0;
s += strspn(s, SPACECHARS); /* skip initial spaces */
if (*s == '-') { s++; neg = 1; } /* handle signal */
else if (*s == '+') s++;
if (isalnum((unsigned char)*s)) {
lua_Number n = 0;
do {
int digit = (isdigit((unsigned char)*s)) ? *s - '0'
: toupper((unsigned char)*s) - 'A' + 10;
if (digit >= base) break; /* invalid numeral; force a fail */
n = n * (lua_Number)base + (lua_Number)digit;
s++;
} while (isalnum((unsigned char)*s));
s += strspn(s, SPACECHARS); /* skip trailing spaces */
if (s == e) { /* no invalid trailing characters? */
lua_pushnumber(L, (neg) ? -n : n);
return 1;
} /* else not a number */
} /* else not a number */
}
lua_pushnil(L); /* not a number */
return 1;
}
static int luaB_error (lua_State *L) {
int level = luaL_optint(L, 2, 1);
lua_settop(L, 1);
if (lua_isstring(L, 1) && level > 0) { /* add extra information? */
luaL_where(L, level);
lua_pushvalue(L, 1);
lua_concat(L, 2);
}
return lua_error(L);
}
static int luaB_getmetatable (lua_State *L) {
luaL_checkany(L, 1);
if (!lua_getmetatable(L, 1)) {
lua_pushnil(L);
return 1; /* no metatable */
}
luaL_getmetafield(L, 1, "__metatable");
return 1; /* returns either __metatable field (if present) or metatable */
}
static int luaB_setmetatable (lua_State *L) {
int t = lua_type(L, 2);
luaL_checktype(L, 1, LUA_TTABLE);
luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,
"nil or table expected");
if (luaL_getmetafield(L, 1, "__metatable"))
return luaL_error(L, "cannot change a protected metatable");
lua_settop(L, 2);
lua_setmetatable(L, 1);
return 1;
}
static int luaB_deprecated (lua_State *L) {
return luaL_error(L, "deprecated function");
}
static int luaB_rawequal (lua_State *L) {
luaL_checkany(L, 1);
luaL_checkany(L, 2);
lua_pushboolean(L, lua_rawequal(L, 1, 2));
return 1;
}
static int luaB_rawlen (lua_State *L) {
int t = lua_type(L, 1);
luaL_argcheck(L, t == LUA_TTABLE || t == LUA_TSTRING, 1,
"table or string expected");
lua_pushinteger(L, lua_rawlen(L, 1));
return 1;
}
static int luaB_rawget (lua_State *L) {
luaL_checktype(L, 1, LUA_TTABLE);
luaL_checkany(L, 2);
lua_settop(L, 2);
lua_rawget(L, 1);
return 1;
}
static int luaB_rawset (lua_State *L) {
luaL_checktype(L, 1, LUA_TTABLE);
luaL_checkany(L, 2);
luaL_checkany(L, 3);
lua_settop(L, 3);
lua_rawset(L, 1);
return 1;
}
static int luaB_collectgarbage (lua_State *L) {
static const char *const opts[] = {"stop", "restart", "collect",
"count", "step", "setpause", "setstepmul",
"setmajorinc", "isrunning", "gen", "inc", NULL};
static const int optsnum[] = {LUA_GCSTOP, LUA_GCRESTART, LUA_GCCOLLECT,
LUA_GCCOUNT, LUA_GCSTEP, LUA_GCSETPAUSE, LUA_GCSETSTEPMUL,
LUA_GCSETMAJORINC, LUA_GCISRUNNING, LUA_GCGEN, LUA_GCINC};
int o = optsnum[luaL_checkoption(L, 1, "collect", opts)];
int ex = luaL_optint(L, 2, 0);
int res = lua_gc(L, o, ex);
switch (o) {
case LUA_GCCOUNT: {
int b = lua_gc(L, LUA_GCCOUNTB, 0);
lua_pushnumber(L, res + ((lua_Number)b/1024));
lua_pushinteger(L, b);
return 2;
}
case LUA_GCSTEP: case LUA_GCISRUNNING: {
lua_pushboolean(L, res);
return 1;
}
default: {
lua_pushinteger(L, res);
return 1;
}
}
}
static int luaB_type (lua_State *L) {
luaL_checkany(L, 1);
lua_pushstring(L, luaL_typename(L, 1));
return 1;
}
static int pairsmeta (lua_State *L, const char *method, int iszero,
lua_CFunction iter) {
if (!luaL_getmetafield(L, 1, method)) { /* no metamethod? */
luaL_checktype(L, 1, LUA_TTABLE); /* argument must be a table */
lua_pushcfunction(L, iter); /* will return generator, */
lua_pushvalue(L, 1); /* state, */
if (iszero) lua_pushinteger(L, 0); /* and initial value */
else lua_pushnil(L);
}
else {
lua_pushvalue(L, 1); /* argument 'self' to metamethod */
lua_call(L, 1, 3); /* get 3 values from metamethod */
}
return 3;
}
static int luaB_next (lua_State *L) {
luaL_checktype(L, 1, LUA_TTABLE);
lua_settop(L, 2); /* create a 2nd argument if there isn't one */
if (lua_next(L, 1))
return 2;
else {
lua_pushnil(L);
return 1;
}
}
static int luaB_pairs (lua_State *L) {
return pairsmeta(L, "__pairs", 0, luaB_next);
}
static int ipairsaux (lua_State *L) {
int i = luaL_checkint(L, 2);
luaL_checktype(L, 1, LUA_TTABLE);
i++; /* next value */
lua_pushinteger(L, i);
lua_rawgeti(L, 1, i);
return (lua_isnil(L, -1)) ? 1 : 2;
}
static int luaB_ipairs (lua_State *L) {
return pairsmeta(L, "__ipairs", 1, ipairsaux);
}
static int load_aux (lua_State *L, int status) {
if (status == LUA_OK)
return 1;
else {
lua_pushnil(L);
lua_insert(L, -2); /* put before error message */
return 2; /* return nil plus error message */
}
}
static int luaB_loadfile (lua_State *L) {
const char *fname = luaL_optstring(L, 1, NULL);
return load_aux(L, luaL_loadfile(L, fname));
}
/*
** {======================================================
** Generic Read function
** =======================================================
*/
/*
** check whether a chunk (prefix in 's') satisfies given 'mode'
** ('t' for text, 'b' for binary). Returns error message (also
** pushed on the stack) in case of errors.
*/
static const char *checkrights (lua_State *L, const char *mode, const char *s) {
if (strchr(mode, 'b') == NULL && *s == LUA_SIGNATURE[0])
return lua_pushstring(L, "attempt to load a binary chunk");
if (strchr(mode, 't') == NULL && *s != LUA_SIGNATURE[0])
return lua_pushstring(L, "attempt to load a text chunk");
return NULL; /* chunk in allowed format */
}
/*
** reserved slot, above all arguments, to hold a copy of the returned
** string to avoid it being collected while parsed. 'load' has four
** optional arguments (chunk, source name, mode, and environment).
*/
#define RESERVEDSLOT 5
/*
** Reader for generic `load' function: `lua_load' uses the
** stack for internal stuff, so the reader cannot change the
** stack top. Instead, it keeps its resulting string in a
** reserved slot inside the stack.
*/
static const char *generic_reader (lua_State *L, void *ud, size_t *size) {
const char *s;
const char **mode = (const char **)ud;
luaL_checkstack(L, 2, "too many nested functions");
lua_pushvalue(L, 1); /* get function */
lua_call(L, 0, 1); /* call it */
if (lua_isnil(L, -1)) {
*size = 0;
return NULL;
}
else if ((s = lua_tostring(L, -1)) != NULL) {
if (*mode != NULL) { /* first time? */
s = checkrights(L, *mode, s); /* check mode */
*mode = NULL; /* to avoid further checks */
if (s) luaL_error(L, s);
}
lua_replace(L, RESERVEDSLOT); /* save string in reserved slot */
return lua_tolstring(L, RESERVEDSLOT, size);
}
else {
luaL_error(L, "reader function must return a string");
return NULL; /* to avoid warnings */
}
}
static int luaB_load (lua_State *L) {
int status;
size_t l;
int top = lua_gettop(L);
const char *s = lua_tolstring(L, 1, &l);
const char *mode = luaL_optstring(L, 3, "bt");
if (s != NULL) { /* loading a string? */
const char *chunkname = luaL_optstring(L, 2, s);
status = (checkrights(L, mode, s) != NULL)
|| luaL_loadbuffer(L, s, l, chunkname);
}
else { /* loading from a reader function */
const char *chunkname = luaL_optstring(L, 2, "=(load)");
luaL_checktype(L, 1, LUA_TFUNCTION);
lua_settop(L, RESERVEDSLOT); /* create reserved slot */
status = lua_load(L, generic_reader, &mode, chunkname);
}
if (status == LUA_OK && top >= 4) { /* is there an 'env' argument */
lua_pushvalue(L, 4); /* environment for loaded function */
lua_setupvalue(L, -2, 1); /* set it as 1st upvalue */
}
return load_aux(L, status);
}
#if defined(LUA_COMPAT_LOADSTRING)
#define luaB_loadstring luaB_load
#else
#define luaB_loadstring luaB_deprecated
#endif
/* }====================================================== */
static int dofilecont (lua_State *L) {
return lua_gettop(L) - 1;
}
static int luaB_dofile (lua_State *L) {
const char *fname = luaL_optstring(L, 1, NULL);
lua_settop(L, 1);
if (luaL_loadfile(L, fname) != LUA_OK) lua_error(L);
lua_callk(L, 0, LUA_MULTRET, 0, dofilecont);
return dofilecont(L);
}
static int luaB_assert (lua_State *L) {
if (!lua_toboolean(L, 1))
return luaL_error(L, "%s", luaL_optstring(L, 2, "assertion failed!"));
return lua_gettop(L);
}
static int luaB_select (lua_State *L) {
int n = lua_gettop(L);
if (lua_type(L, 1) == LUA_TSTRING && *lua_tostring(L, 1) == '#') {
lua_pushinteger(L, n-1);
return 1;
}
else {
int i = luaL_checkint(L, 1);
if (i < 0) i = n + i;
else if (i > n) i = n;
luaL_argcheck(L, 1 <= i, 1, "index out of range");
return n - i;
}
}
static int pcallcont (lua_State *L) {
int errfunc; /* call has an error function in bottom of the stack */
int status = lua_getctx(L, &errfunc);
lua_assert(status != LUA_OK);
lua_pushboolean(L, (status == LUA_YIELD)); /* first result (status) */
if (errfunc) /* came from xpcall? */
lua_replace(L, 1); /* put first result in place of error function */
else /* came from pcall */
lua_insert(L, 1); /* open space for first result */
return lua_gettop(L);
}
static int luaB_pcall (lua_State *L) {
int status;
luaL_checkany(L, 1);
status = lua_pcallk(L, lua_gettop(L) - 1, LUA_MULTRET, 0, 0, pcallcont);
luaL_checkstack(L, 1, NULL);
lua_pushboolean(L, (status == LUA_OK));
lua_insert(L, 1);
return lua_gettop(L); /* return status + all results */
}
static int luaB_xpcall (lua_State *L) {
int status;
int n = lua_gettop(L);
luaL_argcheck(L, n >= 2, 2, "value expected");
lua_pushvalue(L, 1); /* exchange function... */
lua_copy(L, 2, 1); /* ...and error handler */
lua_replace(L, 2);
status = lua_pcallk(L, n - 2, LUA_MULTRET, 1, 1, pcallcont);
luaL_checkstack(L, 1, NULL);
lua_pushboolean(L, (status == LUA_OK));
lua_replace(L, 1);
return lua_gettop(L); /* return status + all results */
}
static int luaB_tostring (lua_State *L) {
luaL_checkany(L, 1);
luaL_tolstring(L, 1, NULL);
return 1;
}
static const luaL_Reg base_funcs[] = {
{"assert", luaB_assert},
{"collectgarbage", luaB_collectgarbage},
{"dofile", luaB_dofile},
{"error", luaB_error},
{"getfenv", luaB_deprecated},
{"getmetatable", luaB_getmetatable},
{"ipairs", luaB_ipairs},
{"loadfile", luaB_loadfile},
{"load", luaB_load},
{"loadstring", luaB_loadstring},
{"next", luaB_next},
{"pairs", luaB_pairs},
{"pcall", luaB_pcall},
{"print", luaB_print},
{"rawequal", luaB_rawequal},
{"rawlen", luaB_rawlen},
{"rawget", luaB_rawget},
{"rawset", luaB_rawset},
{"select", luaB_select},
{"setfenv", luaB_deprecated},
{"setmetatable", luaB_setmetatable},
{"tonumber", luaB_tonumber},
{"tostring", luaB_tostring},
{"type", luaB_type},
{"xpcall", luaB_xpcall},
{NULL, NULL}
};
LUAMOD_API int luaopen_base (lua_State *L) {
/* set global _G */
lua_pushglobaltable(L);
lua_pushglobaltable(L);
lua_setfield(L, -2, "_G");
/* open lib into global table */
luaL_setfuncs(L, base_funcs, 0);
lua_pushliteral(L, LUA_VERSION);
lua_setfield(L, -2, "_VERSION"); /* set global _VERSION */
return 1;
}