lbaselib.c

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      sprintf(buff, "userdata(%d): %p", lua_tag(L, 1), lua_touserdata(L, 1));
      break;
    case LUA_TNIL:
      lua_pushstring(L, "nil");
      return 1;
    default:
      luaL_argerror(L, 1, "value expected");
  }
  lua_pushstring(L, buff);
  return 1;
}


static int luaB_foreachi (lua_State *L) {
  int n, i;
  luaL_checktype(L, 1, LUA_TTABLE);
  luaL_checktype(L, 2, LUA_TFUNCTION);
  n = lua_getn(L, 1);
  for (i=1; i<=n; i++) {
    lua_pushvalue(L, 2);  /* function */
    lua_pushnumber(L, i);  /* 1st argument */
    lua_rawgeti(L, 1, i);  /* 2nd argument */
    lua_rawcall(L, 2, 1);
    if (!lua_isnil(L, -1))
      return 1;
    lua_pop(L, 1);  /* remove nil result */
  }
  return 0;
}


static int luaB_foreach (lua_State *L) {
  luaL_checktype(L, 1, LUA_TTABLE);
  luaL_checktype(L, 2, LUA_TFUNCTION);
  lua_pushnil(L);  /* first index */
  for (;;) {
    if (lua_next(L, 1) == 0)
      return 0;
    lua_pushvalue(L, 2);  /* function */
    lua_pushvalue(L, -3);  /* key */
    lua_pushvalue(L, -3);  /* value */
    lua_rawcall(L, 2, 1);
    if (!lua_isnil(L, -1))
      return 1;
    lua_pop(L, 2);  /* remove value and result */
  }
}


static int luaB_assert (lua_State *L) {
  luaL_checkany(L, 1);
  if (lua_isnil(L, 1))
    luaL_verror(L, "assertion failed!  %.90s", luaL_opt_string(L, 2, ""));
  return 0;
}


static int luaB_getn (lua_State *L) {
  luaL_checktype(L, 1, LUA_TTABLE);
  lua_pushnumber(L, lua_getn(L, 1));
  return 1;
}


static int luaB_tinsert (lua_State *L) {
  int v = lua_gettop(L);  /* last argument: to be inserted */
  int n, pos;
  luaL_checktype(L, 1, LUA_TTABLE);
  n = lua_getn(L, 1);
  if (v == 2)  /* called with only 2 arguments */
    pos = n+1;
  else
    pos = luaL_check_int(L, 2);  /* 2nd argument is the position */
  lua_pushstring(L, "n");
  lua_pushnumber(L, n+1);
  lua_rawset(L, 1);  /* t.n = n+1 */
  for (; n>=pos; n--) {
    lua_rawgeti(L, 1, n);
    lua_rawseti(L, 1, n+1);  /* t[n+1] = t[n] */
  }
  lua_pushvalue(L, v);
  lua_rawseti(L, 1, pos);  /* t[pos] = v */
  return 0;
}


static int luaB_tremove (lua_State *L) {
  int pos, n;
  luaL_checktype(L, 1, LUA_TTABLE);
  n = lua_getn(L, 1);
  pos = luaL_opt_int(L, 2, n);
  if (n <= 0) return 0;  /* table is "empty" */
  lua_rawgeti(L, 1, pos);  /* result = t[pos] */
  for ( ;pos<n; pos++) {
    lua_rawgeti(L, 1, pos+1);
    lua_rawseti(L, 1, pos);  /* a[pos] = a[pos+1] */
  }
  lua_pushstring(L, "n");
  lua_pushnumber(L, n-1);
  lua_rawset(L, 1);  /* t.n = n-1 */
  lua_pushnil(L);
  lua_rawseti(L, 1, n);  /* t[n] = nil */
  return 1;
}




/*
** {======================================================
** Quicksort
** (based on `Algorithms in MODULA-3', Robert Sedgewick;
**  Addison-Wesley, 1993.)
*/


static void set2 (lua_State *L, int i, int j) {
  lua_rawseti(L, 1, i);
  lua_rawseti(L, 1, j);
}

static int sort_comp (lua_State *L, int a, int b) {
  /* WARNING: the caller (auxsort) must ensure stack space */
  if (!lua_isnil(L, 2)) {  /* function? */
    int res;
    lua_pushvalue(L, 2);
    lua_pushvalue(L, a-1);  /* -1 to compensate function */
    lua_pushvalue(L, b-2);  /* -2 to compensate function and `a' */
    lua_rawcall(L, 2, 1);
    res = !lua_isnil(L, -1);
    lua_pop(L, 1);
    return res;
  }
  else  /* a < b? */
    return lua_lessthan(L, a, b);
}

static void auxsort (lua_State *L, int l, int u) {
  while (l < u) {  /* for tail recursion */
    int i, j;
    /* sort elements a[l], a[(l+u)/2] and a[u] */
    lua_rawgeti(L, 1, l);
    lua_rawgeti(L, 1, u);
    if (sort_comp(L, -1, -2))  /* a[u] < a[l]? */
      set2(L, l, u);  /* swap a[l] - a[u] */
    else
      lua_pop(L, 2);
    if (u-l == 1) break;  /* only 2 elements */
    i = (l+u)/2;
    lua_rawgeti(L, 1, i);
    lua_rawgeti(L, 1, l);
    if (sort_comp(L, -2, -1))  /* a[i]<a[l]? */
      set2(L, i, l);
    else {
      lua_pop(L, 1);  /* remove a[l] */
      lua_rawgeti(L, 1, u);
      if (sort_comp(L, -1, -2))  /* a[u]<a[i]? */
        set2(L, i, u);
      else
        lua_pop(L, 2);
    }
    if (u-l == 2) break;  /* only 3 elements */
    lua_rawgeti(L, 1, i);  /* Pivot */
    lua_pushvalue(L, -1);
    lua_rawgeti(L, 1, u-1);
    set2(L, i, u-1);
    /* a[l] <= P == a[u-1] <= a[u], only need to sort from l+1 to u-2 */
    i = l; j = u-1;
    for (;;) {  /* invariant: a[l..i] <= P <= a[j..u] */
      /* repeat ++i until a[i] >= P */
      while (lua_rawgeti(L, 1, ++i), sort_comp(L, -1, -2)) {
        if (i>u) lua_error(L, "invalid order function for sorting");
        lua_pop(L, 1);  /* remove a[i] */
      }
      /* repeat --j until a[j] <= P */
      while (lua_rawgeti(L, 1, --j), sort_comp(L, -3, -1)) {
        if (j<l) lua_error(L, "invalid order function for sorting");
        lua_pop(L, 1);  /* remove a[j] */
      }
      if (j<i) {
        lua_pop(L, 3);  /* pop pivot, a[i], a[j] */
        break;
      }
      set2(L, i, j);
    }
    lua_rawgeti(L, 1, u-1);
    lua_rawgeti(L, 1, i);
    set2(L, u-1, i);  /* swap pivot (a[u-1]) with a[i] */
    /* a[l..i-1] <= a[i] == P <= a[i+1..u] */
    /* adjust so that smaller "half" is in [j..i] and larger one in [l..u] */
    if (i-l < u-i) {
      j=l; i=i-1; l=i+2;
    }
    else {
      j=i+1; i=u; u=j-2;
    }
    auxsort(L, j, i);  /* call recursively the smaller one */
  }  /* repeat the routine for the larger one */
}

static int luaB_sort (lua_State *L) {
  int n;
  luaL_checktype(L, 1, LUA_TTABLE);
  n = lua_getn(L, 1);
  if (!lua_isnull(L, 2))  /* is there a 2nd argument? */
    luaL_checktype(L, 2, LUA_TFUNCTION);
  lua_settop(L, 2);  /* make sure there is two arguments */
  auxsort(L, 1, n);
  return 0;
}

/* }====================================================== */



/*
** {======================================================
** Deprecated functions to manipulate global environment.
** =======================================================
*/


#define num_deprecated	4

static const struct luaL_reg deprecated_names [num_deprecated] = {
  {"foreachvar", luaB_foreach},
  {"nextvar", luaB_next},
  {"rawgetglobal", luaB_rawget},
  {"rawsetglobal", luaB_rawset}
};


#ifdef LUA_DEPRECATEDFUNCS

/*
** call corresponding function inserting `globals' as first argument
*/
static int deprecated_func (lua_State *L) {
  lua_insert(L, 1);  /* upvalue is the function to be called */
  lua_getglobals(L);
  lua_insert(L, 2);  /* table of globals is 1o argument */
  lua_rawcall(L, lua_gettop(L)-1, LUA_MULTRET);
  return lua_gettop(L);  /* return all results */
}


static void deprecated_funcs (lua_State *L) {
  int i;
  for (i=0; i<num_deprecated; i++) {
    lua_pushcfunction(L, deprecated_names[i].func);
    lua_pushcclosure(L, deprecated_func, 1);
    lua_setglobal(L, deprecated_names[i].name);
  }
}


#else

/*
** gives an explicit error in any attempt to call a deprecated function
*/
static int deprecated_func (lua_State *L) {
  luaL_verror(L, "function `%.20s' is deprecated", lua_tostring(L, -1));
  return 0;  /* to avoid warnings */
}


static void deprecated_funcs (lua_State *L) {
  int i;
  for (i=0; i<num_deprecated; i++) {
    lua_pushstring(L, deprecated_names[i].name);
    lua_pushcclosure(L, deprecated_func, 1);
    lua_setglobal(L, deprecated_names[i].name);
  }
}

#endif

/* }====================================================== */

static const struct luaL_reg base_funcs[] = {
  {LUA_ALERT, luaB__ALERT},
  {LUA_ERRORMESSAGE, luaB__ERRORMESSAGE},
  {"call", luaB_call},
  {"collectgarbage", luaB_collectgarbage},
  {"copytagmethods", luaB_copytagmethods},
  {"dofile", luaB_dofile},
  {"dostring", luaB_dostring},
  {"error", luaB_error},
  {"foreach", luaB_foreach},
  {"foreachi", luaB_foreachi},
  {"gcinfo", luaB_gcinfo},
  {"getglobal", luaB_getglobal},
  {"gettagmethod", luaB_gettagmethod},
  {"globals", luaB_globals},
  {"newtag", luaB_newtag},
  {"next", luaB_next},
  {"print", luaB_print},
  {"rawget", luaB_rawget},
  {"rawset", luaB_rawset},
  {"rawgettable", luaB_rawget},  /* for compatibility */
  {"rawsettable", luaB_rawset},  /* for compatibility */
  {"setglobal", luaB_setglobal},
  {"settag", luaB_settag},
  {"settagmethod", luaB_settagmethod},
  {"tag", luaB_tag},
  {"tonumber", luaB_tonumber},
  {"tostring", luaB_tostring},
  {"type", luaB_type},
  {"assert", luaB_assert},
  {"getn", luaB_getn},
  {"sort", luaB_sort},
  {"tinsert", luaB_tinsert},
  {"tremove", luaB_tremove}
};



LUALIB_API void lua_baselibopen (lua_State *L) {
  luaL_openl(L, base_funcs);
  lua_pushstring(L, LUA_VERSION);
  lua_setglobal(L, "_VERSION");
  deprecated_funcs(L);
}