minetest/src/script/common/helper.cpp

/*
Minetest
Copyright (C) 2018 nerzhul, Loic Blot <loic.blot@unix-experience.fr>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#include "helper.h"
#include <cmath>
#include <sstream>
#include "c_types.h"

bool LuaHelper::isNaN(lua_State *L, int idx)
{
	return lua_type(L, idx) == LUA_TNUMBER && std::isnan(lua_tonumber(L, idx));
}

/*
 * Read template functions
 */
template <> bool LuaHelper::readParam(lua_State *L, int index)
{
	return lua_toboolean(L, index) != 0;
}

template <> bool LuaHelper::readParam(lua_State *L, int index, const bool &default_value)
{
	if (lua_isnil(L, index))
		return default_value;

	return lua_toboolean(L, index) != 0;
}

template <> float LuaHelper::readParam(lua_State *L, int index)
{
	if (isNaN(L, index))
		throw LuaError("NaN value is not allowed.");

	return (float)luaL_checknumber(L, index);
}

template <> std::string LuaHelper::readParam(lua_State *L, int index)
{
	std::string result;
	const char *str = luaL_checkstring(L, index);
	result.append(str);
	return result;
}

template <>
std::string LuaHelper::readParam(
		lua_State *L, int index, const std::string &default_value)
{
	std::string result;
	const char *str = lua_tostring(L, index);
	if (str)
		result.append(str);
	else
		result = default_value;
	return result;
}