src/main/java/org/luaj/vm3/LuaUserdata.java

/*******************************************************************************
* Copyright (c) 2009 Luaj.org. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
* 
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
******************************************************************************/
package org.luaj.vm3;

public class LuaUserdata extends LuaValue {

	public Object m_instance;
	public LuaValue m_metatable;

	public LuaUserdata(Object obj) {
		m_instance = obj;
	}

	public LuaUserdata(Object obj, LuaValue metatable) {
		m_instance = obj;
		m_metatable = metatable;
	}

	public String tojstring() {
		return String.valueOf(m_instance);
	}

	public int type() {
		return LuaValue.TUSERDATA;
	}

	public String typename() {
		return "userdata";
	}

	public int hashCode() {
		return m_instance.hashCode();
	}

	public Object userdata() {
		return m_instance;
	}

	public boolean isuserdata() {
		return true;
	}

	public boolean isuserdata(Class c) {
		return c.isAssignableFrom(m_instance.getClass());
	}

	public Object touserdata() {
		return m_instance;
	}

	public Object touserdata(Class c) {
		return c.isAssignableFrom(m_instance.getClass()) ? m_instance : null;
	}

	public Object optuserdata(Object defval) {
		return m_instance;
	}

	public Object optuserdata(Class c, Object defval) {
		if (!c.isAssignableFrom(m_instance.getClass()))
			typerror(c.getName());
		return m_instance;
	}

	public LuaValue getmetatable() {
		return m_metatable;
	}

	public LuaValue setmetatable(LuaValue metatable) {
		this.m_metatable = metatable;
		return this;
	}

	public Object checkuserdata() {
		return m_instance;
	}

	public Object checkuserdata(Class c) {
		if (c.isAssignableFrom(m_instance.getClass()))
			return m_instance;
		return typerror(c.getName());
	}

	public LuaValue get(LuaValue key) {
		return m_metatable != null ? gettable(this, key) : NIL;
	}

	public void set(LuaValue key, LuaValue value) {
		if (m_metatable == null || !settable(this, key, value))
			error("cannot set " + key + " for userdata");
	}

	public boolean equals(Object val) {
		if (this == val)
			return true;
		if (!(val instanceof LuaUserdata))
			return false;
		LuaUserdata u = (LuaUserdata) val;
		return m_instance.equals(u.m_instance);
	}

	// equality w/ metatable processing
	public LuaValue eq(LuaValue val) {
		return eq_b(val) ? TRUE : FALSE;
	}

	public boolean eq_b(LuaValue val) {
		if (val.raweq(this))
			return true;
		if (m_metatable == null || !val.isuserdata())
			return false;
		LuaValue valmt = val.getmetatable();
		return valmt != null && LuaValue.eqmtcall(this, m_metatable, val, valmt);
	}

	// equality w/o metatable processing
	public boolean raweq(LuaValue val) {
		return val.raweq(this);
	}

	public boolean raweq(LuaUserdata val) {
		return this == val || (m_metatable == val.m_metatable && m_instance.equals(val.m_instance));
	}

	// __eq metatag processing
	public boolean eqmt(LuaValue val) {
		return m_metatable != null && val.isuserdata() ? LuaValue.eqmtcall(this, m_metatable, val, val.getmetatable()) : false;
	}
}