/*

** $Id: lbaselib.c,v 1.191.1.6 2008/02/14 16:46:22 roberto Exp $

** 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"

/*

** If your system does not support `stdout', you can just remove this function.

** If you need, you can define your own `print' function, following this

** model but changing `fputs' to put the strings at a proper place

** (a console window or a log file, for instance).

*/

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;

    lua_pushvalue(L, -1);  /* function to be called */

    lua_pushvalue(L, i);   /* value to print */

    lua_call(L, 1, 1);

    s = lua_tostring(L, -1);  /* get result */

    if (s == NULL)

      return luaL_error(L, LUA_QL("tostring") " must return a string to "

                           LUA_QL("print"));

    if (i>1) fputs("\t", stdout);

    fputs(s, stdout);

    lua_pop(L, 1);  /* pop result */

  }

  fputs("\n", stdout);

  return 0;

}

static int luaB_tonumber (lua_State *L) {

  int base = luaL_optint(L, 2, 10);

  if (base == 10) {  /* standard conversion */

    luaL_checkany(L, 1);

    if (lua_isnumber(L, 1)) {

      lua_pushnumber(L, lua_tonumber(L, 1));

      return 1;

    }

  }

  else {

    const char *s1 = luaL_checkstring(L, 1);

    char *s2;

    unsigned long n;

    luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range");

    n = strtoul(s1, &s2, base);

    if (s1 != s2) {  /* at least one valid digit? */

      while (isspace((unsigned char)(*s2))) s2++;  /* skip trailing spaces */

      if (*s2 == '\0') {  /* no invalid trailing characters? */

        lua_pushnumber(L, (lua_Number)n);

        return 1;

      }

    }

  }

  lua_pushnil(L);  /* else 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"))

    luaL_error(L, "cannot change a protected metatable");

  lua_settop(L, 2);

  lua_setmetatable(L, 1);

  return 1;

}

static void getfunc (lua_State *L, int opt) {

  if (lua_isfunction(L, 1)) lua_pushvalue(L, 1);

  else {

    lua_Debug ar;

    int level = opt ? luaL_optint(L, 1, 1) : luaL_checkint(L, 1);

    luaL_argcheck(L, level >= 0, 1, "level must be non-negative");

    if (lua_getstack(L, level, &ar) == 0)

      luaL_argerror(L, 1, "invalid level");

    lua_getinfo(L, "f", &ar);

    if (lua_isnil(L, -1))

      luaL_error(L, "no function environment for tail call at level %d",

                    level);

  }

}

static int luaB_getfenv (lua_State *L) {

  getfunc(L, 1);

  if (lua_iscfunction(L, -1))  /* is a C function? */

    lua_pushvalue(L, LUA_GLOBALSINDEX);  /* return the thread's global env. */

  else

    lua_getfenv(L, -1);

  return 1;

}

static int luaB_setfenv (lua_State *L) {

  luaL_checktype(L, 2, LUA_TTABLE);

  getfunc(L, 0);

  lua_pushvalue(L, 2);

  if (lua_isnumber(L, 1) && lua_tonumber(L, 1) == 0) {

    /* change environment of current thread */

    lua_pushthread(L);

    lua_insert(L, -2);

    lua_setfenv(L, -2);

    return 0;

  }

  else if (lua_iscfunction(L, -2) || lua_setfenv(L, -2) == 0)

    luaL_error(L,

          LUA_QL("setfenv") " cannot change environment of given object");

  return 1;

}

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_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_gcinfo (lua_State *L) {

  lua_pushinteger(L, lua_getgccount(L));

  return 1;

}

static int luaB_collectgarbage (lua_State *L) {

  static const char *const opts[] = {"stop", "restart", "collect",

    "count", "step", "setpause", "setstepmul", NULL};

  static const int optsnum[] = {LUA_GCSTOP, LUA_GCRESTART, LUA_GCCOLLECT,

    LUA_GCCOUNT, LUA_GCSTEP, LUA_GCSETPAUSE, LUA_GCSETSTEPMUL};

  int o = luaL_checkoption(L, 1, "collect", opts);

  int ex = luaL_optint(L, 2, 0);

  int res = lua_gc(L, optsnum[o], ex);

  switch (optsnum[o]) {

    case LUA_GCCOUNT: {

      int b = lua_gc(L, LUA_GCCOUNTB, 0);

      lua_pushnumber(L, res + ((lua_Number)b/1024));

      return 1;

    }

    case LUA_GCSTEP: {

      lua_pushboolean(L, res);

      return 1;

    }

    default: {

      lua_pushnumber(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 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) {

  luaL_checktype(L, 1, LUA_TTABLE);

  lua_pushvalue(L, lua_upvalueindex(1));  /* return generator, */

  lua_pushvalue(L, 1);  /* state, */

  lua_pushnil(L);  /* and initial value */

  return 3;

}

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)) ? 0 : 2;

}

static int luaB_ipairs (lua_State *L) {

  luaL_checktype(L, 1, LUA_TTABLE);

  lua_pushvalue(L, lua_upvalueindex(1));  /* return generator, */

  lua_pushvalue(L, 1);  /* state, */

  lua_pushinteger(L, 0);  /* and initial value */

  return 3;

}

static int load_aux (lua_State *L, int status) {

  if (status == 0)  /* 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_loadstring (lua_State *L) {

  size_t l;

  const char *s = luaL_checklstring(L, 1, &l);

  const char *chunkname = luaL_optstring(L, 2, s);

  return load_aux(L, luaL_loadbuffer(L, s, l, chunkname));

}

static int luaB_loadfile (lua_State *L) {

  const char *fname = luaL_optstring(L, 1, NULL);

  return load_aux(L, luaL_loadfile(L, fname));

}

/*

** 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) {

  (void)ud;  /* to avoid warnings */

  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 (lua_isstring(L, -1)) {

    lua_replace(L, 3);  /* save string in a reserved stack slot */

    return lua_tolstring(L, 3, 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;

  const char *cname = luaL_optstring(L, 2, "=(load)");

  luaL_checktype(L, 1, LUA_TFUNCTION);

  lua_settop(L, 3);  /* function, eventual name, plus one reserved slot */

  status = lua_load(L, generic_reader, NULL, cname);

  return load_aux(L, status);

}

static int luaB_dofile (lua_State *L) {

  const char *fname = luaL_optstring(L, 1, NULL);

  int n = lua_gettop(L);

  if (luaL_loadfile(L, fname) != 0) lua_error(L);

  lua_call(L, 0, LUA_MULTRET);

  return lua_gettop(L) - n;

}

static int luaB_assert (lua_State *L) {

  luaL_checkany(L, 1);

  if (!lua_toboolean(L, 1))

    return luaL_error(L, "%s", luaL_optstring(L, 2, "assertion failed!"));

  return lua_gettop(L);

}

static int luaB_unpack (lua_State *L) {

  int i, e, n;

  luaL_checktype(L, 1, LUA_TTABLE);

  i = luaL_optint(L, 2, 1);

  e = luaL_opt(L, luaL_checkint, 3, luaL_getn(L, 1));

  if (i > e) return 0;  /* empty range */

  n = e - i + 1;  /* number of elements */

  if (n <= 0 || !lua_checkstack(L, n))  /* n <= 0 means arith. overflow */

    return luaL_error(L, "too many results to unpack");

  lua_rawgeti(L, 1, i);  /* push arg[i] (avoiding overflow problems) */

  while (i++ < e)  /* push arg[i + 1...e] */

    lua_rawgeti(L, 1, i);

  return n;

}

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 luaB_pcall (lua_State *L) {

  int status;

  luaL_checkany(L, 1);

  status = lua_pcall(L, lua_gettop(L) - 1, LUA_MULTRET, 0);

  lua_pushboolean(L, (status == 0));

  lua_insert(L, 1);

  return lua_gettop(L);  /* return status + all results */

}

static int luaB_xpcall (lua_State *L) {

  int status;

  luaL_checkany(L, 2);

  lua_settop(L, 2);

  lua_insert(L, 1);  /* put error function under function to be called */

  status = lua_pcall(L, 0, LUA_MULTRET, 1);

  lua_pushboolean(L, (status == 0));

  lua_replace(L, 1);

  return lua_gettop(L);  /* return status + all results */

}

static int luaB_tostring (lua_State *L) {

  luaL_checkany(L, 1);

  if (luaL_callmeta(L, 1, "__tostring"))  /* is there a metafield? */

    return 1;  /* use its value */

  switch (lua_type(L, 1)) {

    case LUA_TNUMBER:

      lua_pushstring(L, lua_tostring(L, 1));

      break;

    case LUA_TSTRING:

      lua_pushvalue(L, 1);

      break;

    case LUA_TBOOLEAN:

      lua_pushstring(L, (lua_toboolean(L, 1) ? "true" : "false"));

      break;

    case LUA_TNIL:

      lua_pushliteral(L, "nil");

      break;

    default:

      lua_pushfstring(L, "%s: %p", luaL_typename(L, 1), lua_topointer(L, 1));

      break;

  }

  return 1;