org/luaj/vm2/lib/jse/CoerceLuaToJava.java - minecraft/opencomputers - Rivoreo Source Code Repositories

 /*******************************************************************************
 * Copyright (c) 2009-2011 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.vm2.lib.jse;

 import java.lang.reflect.Array;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;

 import org.luaj.vm2.LuaString;
 import org.luaj.vm2.LuaTable;
 import org.luaj.vm2.LuaValue;

 /**
  * Helper class to coerce values from lua to Java within the luajava library.
  * <p>
  * This class is primarily used by the {@link LuajavaLib},
  * but can also be used directly when working with Java/lua bindings.
  * <p>
  * To coerce to specific Java values, generally the {@code toType()} methods
  * on {@link LuaValue} may be used:
  * <ul>
  * <li>{@link LuaValue#toboolean()}</li>
  * <li>{@link LuaValue#tobyte()}</li>
  * <li>{@link LuaValue#tochar()}</li>
  * <li>{@link LuaValue#toshort()}</li>
  * <li>{@link LuaValue#toint()}</li>
  * <li>{@link LuaValue#tofloat()}</li>
  * <li>{@link LuaValue#todouble()}</li>
  * <li>{@link LuaValue#tojstring()}</li>
  * <li>{@link LuaValue#touserdata()}</li>
  * <li>{@link LuaValue#touserdata(Class)}</li>
  * </ul>
  * <p>
  * For data in lua tables, the various methods on {@link LuaTable} can be used directly
  * to convert data to something more useful.
  *
  * @see LuajavaLib
  * @see CoerceJavaToLua
  */
 public class CoerceLuaToJava {

 	static int SCORE_NULL_VALUE     =    0x10;
 	static int SCORE_WRONG_TYPE     =   0x100;
 	static int SCORE_UNCOERCIBLE    = 0x10000;

 	static interface Coercion {
 		public int score( LuaValue value );
 		public Object coerce( LuaValue value );
 	};

 	/**
 	 * Coerce a LuaValue value to a specified java class
 	 * @param value LuaValue to coerce
 	 * @param clazz Class to coerce into
 	 * @return Object of type clazz (or a subclass) with the corresponding value.
 	 */
 	public static Object coerce(LuaValue value, Class clazz) {
 		return getCoercion(clazz).coerce(value);
 	}

 	static final Map COERCIONS = Collections.synchronizedMap(new HashMap());

 	static final class BoolCoercion implements Coercion {
 		public String toString() {
 			return "BoolCoercion()";
 		}
 		public int score( LuaValue value ) {
 			switch ( value.type() ) {
 			case LuaValue.TBOOLEAN:
 				return 0;
 			}
 			return 1;
 		}

 		public Object coerce(LuaValue value) {
 			return value.toboolean()? Boolean.TRUE: Boolean.FALSE;
 		}
 	}

 	static final class NumericCoercion implements Coercion {
 		static final int TARGET_TYPE_BYTE = 0;
 		static final int TARGET_TYPE_CHAR = 1;
 		static final int TARGET_TYPE_SHORT = 2;
 		static final int TARGET_TYPE_INT = 3;
 		static final int TARGET_TYPE_LONG = 4;
 		static final int TARGET_TYPE_FLOAT = 5;
 		static final int TARGET_TYPE_DOUBLE = 6;
 		static final String[] TYPE_NAMES = { "byte", "char", "short", "int", "long", "float", "double" };
 		final int targetType;
 		public String toString() {
 			return "NumericCoercion("+TYPE_NAMES[targetType]+")";
 		}
 		NumericCoercion(int targetType) {
 			this.targetType = targetType;
 		}
 		public int score( LuaValue value ) {
 			int fromStringPenalty = 0;
 			if ( value.type() == LuaValue.TSTRING ) {
 				value = value.tonumber();
 				if ( value.isnil() ) {
 					return SCORE_UNCOERCIBLE;
 				}
 				fromStringPenalty = 4;
 			}
 			if ( value.isint() ) {
 				switch ( targetType ) {
 				case TARGET_TYPE_BYTE: {
 					int i = value.toint();
 					return fromStringPenalty + ((i==(byte)i)? 0: SCORE_WRONG_TYPE);
 				}
 				case TARGET_TYPE_CHAR: {
 					int i = value.toint();
 					return fromStringPenalty + ((i==(byte)i)? 1: (i==(char)i)? 0: SCORE_WRONG_TYPE);
 				}
 				case TARGET_TYPE_SHORT: {
 					int i = value.toint();
 					return fromStringPenalty +
 							((i==(byte)i)? 1: (i==(short)i)? 0: SCORE_WRONG_TYPE);
 				}
 				case TARGET_TYPE_INT: {
 					int i = value.toint();
 					return fromStringPenalty +
 							((i==(byte)i)? 2: ((i==(char)i) || (i==(short)i))? 1: 0);
 				}
 				case TARGET_TYPE_FLOAT: return fromStringPenalty + 1;
 				case TARGET_TYPE_LONG: return fromStringPenalty + 1;
 				case TARGET_TYPE_DOUBLE: return fromStringPenalty + 2;
 				default: return SCORE_WRONG_TYPE;
 				}
 			} else if ( value.isnumber() ) {
 				switch ( targetType ) {
 				case TARGET_TYPE_BYTE: return SCORE_WRONG_TYPE;
 				case TARGET_TYPE_CHAR: return SCORE_WRONG_TYPE;
 				case TARGET_TYPE_SHORT: return SCORE_WRONG_TYPE;
 				case TARGET_TYPE_INT: return SCORE_WRONG_TYPE;
 				case TARGET_TYPE_LONG: {
 					double d = value.todouble();
 					return fromStringPenalty + ((d==(long)d)? 0: SCORE_WRONG_TYPE);
 				}
 				case TARGET_TYPE_FLOAT: {
 					double d = value.todouble();
 					return fromStringPenalty + ((d==(float)d)? 0: SCORE_WRONG_TYPE);
 				}
 				case TARGET_TYPE_DOUBLE: {
 					double d = value.todouble();
 					return fromStringPenalty + (((d==(long)d) || (d==(float)d))? 1: 0);
 				}
 				default: return SCORE_WRONG_TYPE;
 				}
 			} else {
 				return SCORE_UNCOERCIBLE;
 			}
 		}

 		public Object coerce(LuaValue value) {
 			switch ( targetType ) {
 			case TARGET_TYPE_BYTE: return new Byte( (byte) value.toint() );
 			case TARGET_TYPE_CHAR: return new Character( (char) value.toint() );
 			case TARGET_TYPE_SHORT: return new Short( (short) value.toint() );
 			case TARGET_TYPE_INT: return new Integer( (int) value.toint() );
 			case TARGET_TYPE_LONG: return new Long( (long) value.todouble() );
 			case TARGET_TYPE_FLOAT: return new Float( (float) value.todouble() );
 			case TARGET_TYPE_DOUBLE: return new Double( (double) value.todouble() );
 			default: return null;
 			}
 		}
 	}

 	static final class StringCoercion implements Coercion {
 		public static final int TARGET_TYPE_STRING = 0;
 		public static final int TARGET_TYPE_BYTES = 1;
 		final int targetType;
 		public StringCoercion(int targetType) {
 			this.targetType = targetType;
 		}
 		public String toString() {
 			return "StringCoercion("+(targetType==TARGET_TYPE_STRING? "String": "byte[]")+")";
 		}
 		public int score(LuaValue value) {
 			switch ( value.type() ) {
 			case LuaValue.TSTRING:
 				return value.checkstring().isValidUtf8()?
 						(targetType==TARGET_TYPE_STRING? 0: 1):
 						(targetType==TARGET_TYPE_BYTES? 0: SCORE_WRONG_TYPE);
 			case LuaValue.TNIL:
 				return SCORE_NULL_VALUE;
 			default:
 				return targetType == TARGET_TYPE_STRING? SCORE_WRONG_TYPE: SCORE_UNCOERCIBLE;
 			}
 		}
 		public Object coerce(LuaValue value) {
 			if ( value.isnil() )
 				return null;
 			if ( targetType == TARGET_TYPE_STRING )
 				return value.tojstring();
 			LuaString s = value.checkstring();
 			byte[] b = new byte[s.m_length];
 			s.copyInto(0, b, 0, b.length);
 			return b;
 		}
 	}

 	static final class ArrayCoercion implements Coercion {
 		final Class componentType;
 		final Coercion componentCoercion;
 		public ArrayCoercion(Class componentType) {
 			this.componentType = componentType;
 			this.componentCoercion = getCoercion(componentType);
 		}
 		public String toString() {
 			return "ArrayCoercion("+componentType.getName()+")";
 		}
 		public int score(LuaValue value) {
 			switch ( value.type() ) {
 			case LuaValue.TTABLE:
 				return value.length()==0? 0: componentCoercion.score( value.get(1) );
 			case LuaValue.TUSERDATA:
 				return inheritanceLevels( componentType, value.touserdata().getClass().getComponentType() );
 			case LuaValue.TNIL:
 				return SCORE_NULL_VALUE;
 			default:
 				return SCORE_UNCOERCIBLE;
 			}
 		}
 		public Object coerce(LuaValue value) {
 			switch ( value.type() ) {
 			case LuaValue.TTABLE: {
 				int n = value.length();
 				Object a = Array.newInstance(componentType, n);
 				for ( int i=0; i<n; i++ )
 					Array.set(a, i, componentCoercion.coerce(value.get(i+1)));
 				return a;
 			}
 			case LuaValue.TUSERDATA:
 				return value.touserdata();
 			case LuaValue.TNIL:
 				return null;
 			default:
 				return null;
 			}

 		}
 	}

 	/**
 	 * Determine levels of inheritance between a base class and a subclass
 	 * @param baseclass base class to look for
 	 * @param subclass class from which to start looking
 	 * @return number of inheritance levels between subclass and baseclass,
 	 * or SCORE_UNCOERCIBLE if not a subclass
 	 */
 	static final int inheritanceLevels( Class baseclass, Class subclass ) {
 		if ( subclass == null )
 			return SCORE_UNCOERCIBLE;
 		if ( baseclass == subclass )
 			return 0;
 		int min = Math.min( SCORE_UNCOERCIBLE, inheritanceLevels( baseclass, subclass.getSuperclass() ) + 1 );
 		Class[] ifaces = subclass.getInterfaces();
 		for ( int i=0; i<ifaces.length; i++ )
 			min = Math.min(min, inheritanceLevels(baseclass, ifaces[i]) + 1 );
 		return min;
 	}

 	static final class ObjectCoercion implements Coercion {
 		final Class targetType;
 		ObjectCoercion(Class targetType) {
 			this.targetType = targetType;
 		}
 		public String toString() {
 			return "ObjectCoercion("+targetType.getName()+")";
 		}
 		public int score(LuaValue value) {
 			switch ( value.type() ) {
 			case LuaValue.TNUMBER:
 				return inheritanceLevels( targetType, value.isint()? Integer.class: Double.class );
 			case LuaValue.TBOOLEAN:
 				return inheritanceLevels( targetType, Boolean.class );
 			case LuaValue.TSTRING:
 				return inheritanceLevels( targetType, String.class );
 			case LuaValue.TUSERDATA:
 				return inheritanceLevels( targetType, value.touserdata().getClass() );
 			case LuaValue.TNIL:
 				return SCORE_NULL_VALUE;
 			default:
 				return inheritanceLevels( targetType, value.getClass() );
 			}
 		}
 		public Object coerce(LuaValue value) {
 			switch ( value.type() ) {
 			case LuaValue.TNUMBER:
 				return value.isint()? (Object)new Integer(value.toint()): (Object)new Double(value.todouble());
 			case LuaValue.TBOOLEAN:
 				return value.toboolean()? Boolean.TRUE: Boolean.FALSE;
 			case LuaValue.TSTRING:
 				return value.tojstring();
 			case LuaValue.TUSERDATA:
 				return value.optuserdata(targetType, null);
 			case LuaValue.TNIL:
 				return null;
 			default:
 				return value;
 			}
 		}
 	}

 	static {
 		Coercion boolCoercion   = new BoolCoercion();
 		Coercion byteCoercion   = new NumericCoercion(NumericCoercion.TARGET_TYPE_BYTE);
 		Coercion charCoercion   = new NumericCoercion(NumericCoercion.TARGET_TYPE_CHAR);
 		Coercion shortCoercion  = new NumericCoercion(NumericCoercion.TARGET_TYPE_SHORT);
 		Coercion intCoercion    = new NumericCoercion(NumericCoercion.TARGET_TYPE_INT);
 		Coercion longCoercion   = new NumericCoercion(NumericCoercion.TARGET_TYPE_LONG);
 		Coercion floatCoercion  = new NumericCoercion(NumericCoercion.TARGET_TYPE_FLOAT);
 		Coercion doubleCoercion = new NumericCoercion(NumericCoercion.TARGET_TYPE_DOUBLE);
 		Coercion stringCoercion = new StringCoercion(StringCoercion.TARGET_TYPE_STRING);
 		Coercion bytesCoercion  = new StringCoercion(StringCoercion.TARGET_TYPE_BYTES);

 		COERCIONS.put( Boolean.TYPE, boolCoercion );
 		COERCIONS.put( Boolean.class, boolCoercion );
 		COERCIONS.put( Byte.TYPE, byteCoercion );
 		COERCIONS.put( Byte.class, byteCoercion );
 		COERCIONS.put( Character.TYPE, charCoercion );
 		COERCIONS.put( Character.class, charCoercion );
 		COERCIONS.put( Short.TYPE, shortCoercion );
 		COERCIONS.put( Short.class, shortCoercion );
 		COERCIONS.put( Integer.TYPE, intCoercion );
 		COERCIONS.put( Integer.class, intCoercion );
 		COERCIONS.put( Long.TYPE, longCoercion );
 		COERCIONS.put( Long.class, longCoercion );
 		COERCIONS.put( Float.TYPE, floatCoercion );
 		COERCIONS.put( Float.class, floatCoercion );
 		COERCIONS.put( Double.TYPE, doubleCoercion );
 		COERCIONS.put( Double.class, doubleCoercion );
 		COERCIONS.put( String.class, stringCoercion );
 		COERCIONS.put( byte[].class, bytesCoercion );
 	}

 	static Coercion getCoercion(Class c) {
 		Coercion co = (Coercion) COERCIONS.get( c );
 		if ( co != null ) {
 			return co;
 		}
 		if ( c.isArray() ) {
 			Class typ = c.getComponentType();
 			co = new ArrayCoercion(c.getComponentType());
 		} else {
 			co = new ObjectCoercion(c);
 		}
 		COERCIONS.put( c, co );
 		return co;
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2009-2011 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.vm2.lib.jse;

	import java.lang.reflect.Array;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.Map;

	import org.luaj.vm2.LuaString;
	import org.luaj.vm2.LuaTable;
	import org.luaj.vm2.LuaValue;

	/**
	* Helper class to coerce values from lua to Java within the luajava library.
	* <p>
	* This class is primarily used by the {@link LuajavaLib},
	* but can also be used directly when working with Java/lua bindings.
	* <p>
	* To coerce to specific Java values, generally the {@code toType()} methods
	* on {@link LuaValue} may be used:
	* <ul>
	* <li>{@link LuaValue#toboolean()}</li>
	* <li>{@link LuaValue#tobyte()}</li>
	* <li>{@link LuaValue#tochar()}</li>
	* <li>{@link LuaValue#toshort()}</li>
	* <li>{@link LuaValue#toint()}</li>
	* <li>{@link LuaValue#tofloat()}</li>
	* <li>{@link LuaValue#todouble()}</li>
	* <li>{@link LuaValue#tojstring()}</li>
	* <li>{@link LuaValue#touserdata()}</li>
	* <li>{@link LuaValue#touserdata(Class)}</li>
	* </ul>
	* <p>
	* For data in lua tables, the various methods on {@link LuaTable} can be used directly
	* to convert data to something more useful.
	*
	* @see LuajavaLib
	* @see CoerceJavaToLua
	*/
	public class CoerceLuaToJava {

	static int SCORE_NULL_VALUE = 0x10;
	static int SCORE_WRONG_TYPE = 0x100;
	static int SCORE_UNCOERCIBLE = 0x10000;

	static interface Coercion {
	public int score( LuaValue value );
	public Object coerce( LuaValue value );
	};

	/**
	* Coerce a LuaValue value to a specified java class
	* @param value LuaValue to coerce
	* @param clazz Class to coerce into
	* @return Object of type clazz (or a subclass) with the corresponding value.
	*/
	public static Object coerce(LuaValue value, Class clazz) {
	return getCoercion(clazz).coerce(value);
	}

	static final Map COERCIONS = Collections.synchronizedMap(new HashMap());

	static final class BoolCoercion implements Coercion {
	public String toString() {
	return "BoolCoercion()";
	}
	public int score( LuaValue value ) {
	switch ( value.type() ) {
	case LuaValue.TBOOLEAN:
	return 0;
	}
	return 1;
	}

	public Object coerce(LuaValue value) {
	return value.toboolean()? Boolean.TRUE: Boolean.FALSE;
	}
	}

	static final class NumericCoercion implements Coercion {
	static final int TARGET_TYPE_BYTE = 0;
	static final int TARGET_TYPE_CHAR = 1;
	static final int TARGET_TYPE_SHORT = 2;
	static final int TARGET_TYPE_INT = 3;
	static final int TARGET_TYPE_LONG = 4;
	static final int TARGET_TYPE_FLOAT = 5;
	static final int TARGET_TYPE_DOUBLE = 6;
	static final String[] TYPE_NAMES = { "byte", "char", "short", "int", "long", "float", "double" };
	final int targetType;
	public String toString() {
	return "NumericCoercion("+TYPE_NAMES[targetType]+")";
	}
	NumericCoercion(int targetType) {
	this.targetType = targetType;
	}
	public int score( LuaValue value ) {
	int fromStringPenalty = 0;
	if ( value.type() == LuaValue.TSTRING ) {
	value = value.tonumber();
	if ( value.isnil() ) {
	return SCORE_UNCOERCIBLE;
	}
	fromStringPenalty = 4;
	}
	if ( value.isint() ) {
	switch ( targetType ) {
	case TARGET_TYPE_BYTE: {
	int i = value.toint();
	return fromStringPenalty + ((i==(byte)i)? 0: SCORE_WRONG_TYPE);
	}
	case TARGET_TYPE_CHAR: {
	int i = value.toint();
	return fromStringPenalty + ((i==(byte)i)? 1: (i==(char)i)? 0: SCORE_WRONG_TYPE);
	}
	case TARGET_TYPE_SHORT: {
	int i = value.toint();
	return fromStringPenalty +
	((i==(byte)i)? 1: (i==(short)i)? 0: SCORE_WRONG_TYPE);
	}
	case TARGET_TYPE_INT: {
	int i = value.toint();
	return fromStringPenalty +
	((i==(byte)i)? 2: ((i==(char)i) \|\| (i==(short)i))? 1: 0);
	}
	case TARGET_TYPE_FLOAT: return fromStringPenalty + 1;
	case TARGET_TYPE_LONG: return fromStringPenalty + 1;
	case TARGET_TYPE_DOUBLE: return fromStringPenalty + 2;
	default: return SCORE_WRONG_TYPE;
	}
	} else if ( value.isnumber() ) {
	switch ( targetType ) {
	case TARGET_TYPE_BYTE: return SCORE_WRONG_TYPE;
	case TARGET_TYPE_CHAR: return SCORE_WRONG_TYPE;
	case TARGET_TYPE_SHORT: return SCORE_WRONG_TYPE;
	case TARGET_TYPE_INT: return SCORE_WRONG_TYPE;
	case TARGET_TYPE_LONG: {
	double d = value.todouble();
	return fromStringPenalty + ((d==(long)d)? 0: SCORE_WRONG_TYPE);
	}
	case TARGET_TYPE_FLOAT: {
	double d = value.todouble();
	return fromStringPenalty + ((d==(float)d)? 0: SCORE_WRONG_TYPE);
	}
	case TARGET_TYPE_DOUBLE: {
	double d = value.todouble();
	return fromStringPenalty + (((d==(long)d) \|\| (d==(float)d))? 1: 0);
	}
	default: return SCORE_WRONG_TYPE;
	}
	} else {
	return SCORE_UNCOERCIBLE;
	}
	}

	public Object coerce(LuaValue value) {
	switch ( targetType ) {
	case TARGET_TYPE_BYTE: return new Byte( (byte) value.toint() );
	case TARGET_TYPE_CHAR: return new Character( (char) value.toint() );
	case TARGET_TYPE_SHORT: return new Short( (short) value.toint() );
	case TARGET_TYPE_INT: return new Integer( (int) value.toint() );
	case TARGET_TYPE_LONG: return new Long( (long) value.todouble() );
	case TARGET_TYPE_FLOAT: return new Float( (float) value.todouble() );
	case TARGET_TYPE_DOUBLE: return new Double( (double) value.todouble() );
	default: return null;
	}
	}
	}

	static final class StringCoercion implements Coercion {
	public static final int TARGET_TYPE_STRING = 0;
	public static final int TARGET_TYPE_BYTES = 1;
	final int targetType;
	public StringCoercion(int targetType) {
	this.targetType = targetType;
	}
	public String toString() {
	return "StringCoercion("+(targetType==TARGET_TYPE_STRING? "String": "byte[]")+")";
	}
	public int score(LuaValue value) {
	switch ( value.type() ) {
	case LuaValue.TSTRING:
	return value.checkstring().isValidUtf8()?
	(targetType==TARGET_TYPE_STRING? 0: 1):
	(targetType==TARGET_TYPE_BYTES? 0: SCORE_WRONG_TYPE);
	case LuaValue.TNIL:
	return SCORE_NULL_VALUE;
	default:
	return targetType == TARGET_TYPE_STRING? SCORE_WRONG_TYPE: SCORE_UNCOERCIBLE;
	}
	}
	public Object coerce(LuaValue value) {
	if ( value.isnil() )
	return null;
	if ( targetType == TARGET_TYPE_STRING )
	return value.tojstring();
	LuaString s = value.checkstring();
	byte[] b = new byte[s.m_length];
	s.copyInto(0, b, 0, b.length);
	return b;
	}
	}

	static final class ArrayCoercion implements Coercion {
	final Class componentType;
	final Coercion componentCoercion;
	public ArrayCoercion(Class componentType) {
	this.componentType = componentType;
	this.componentCoercion = getCoercion(componentType);
	}
	public String toString() {
	return "ArrayCoercion("+componentType.getName()+")";
	}
	public int score(LuaValue value) {
	switch ( value.type() ) {
	case LuaValue.TTABLE:
	return value.length()==0? 0: componentCoercion.score( value.get(1) );
	case LuaValue.TUSERDATA:
	return inheritanceLevels( componentType, value.touserdata().getClass().getComponentType() );
	case LuaValue.TNIL:
	return SCORE_NULL_VALUE;
	default:
	return SCORE_UNCOERCIBLE;
	}
	}
	public Object coerce(LuaValue value) {
	switch ( value.type() ) {
	case LuaValue.TTABLE: {
	int n = value.length();
	Object a = Array.newInstance(componentType, n);
	for ( int i=0; i<n; i++ )
	Array.set(a, i, componentCoercion.coerce(value.get(i+1)));
	return a;
	}
	case LuaValue.TUSERDATA:
	return value.touserdata();
	case LuaValue.TNIL:
	return null;
	default:
	return null;
	}

	}
	}

	/**
	* Determine levels of inheritance between a base class and a subclass
	* @param baseclass base class to look for
	* @param subclass class from which to start looking
	* @return number of inheritance levels between subclass and baseclass,
	* or SCORE_UNCOERCIBLE if not a subclass
	*/
	static final int inheritanceLevels( Class baseclass, Class subclass ) {
	if ( subclass == null )
	return SCORE_UNCOERCIBLE;
	if ( baseclass == subclass )
	return 0;
	int min = Math.min( SCORE_UNCOERCIBLE, inheritanceLevels( baseclass, subclass.getSuperclass() ) + 1 );
	Class[] ifaces = subclass.getInterfaces();
	for ( int i=0; i<ifaces.length; i++ )
	min = Math.min(min, inheritanceLevels(baseclass, ifaces[i]) + 1 );
	return min;
	}

	static final class ObjectCoercion implements Coercion {
	final Class targetType;
	ObjectCoercion(Class targetType) {
	this.targetType = targetType;
	}
	public String toString() {
	return "ObjectCoercion("+targetType.getName()+")";
	}
	public int score(LuaValue value) {
	switch ( value.type() ) {
	case LuaValue.TNUMBER:
	return inheritanceLevels( targetType, value.isint()? Integer.class: Double.class );
	case LuaValue.TBOOLEAN:
	return inheritanceLevels( targetType, Boolean.class );
	case LuaValue.TSTRING:
	return inheritanceLevels( targetType, String.class );
	case LuaValue.TUSERDATA:
	return inheritanceLevels( targetType, value.touserdata().getClass() );
	case LuaValue.TNIL:
	return SCORE_NULL_VALUE;
	default:
	return inheritanceLevels( targetType, value.getClass() );
	}
	}
	public Object coerce(LuaValue value) {
	switch ( value.type() ) {
	case LuaValue.TNUMBER:
	return value.isint()? (Object)new Integer(value.toint()): (Object)new Double(value.todouble());
	case LuaValue.TBOOLEAN:
	return value.toboolean()? Boolean.TRUE: Boolean.FALSE;
	case LuaValue.TSTRING:
	return value.tojstring();
	case LuaValue.TUSERDATA:
	return value.optuserdata(targetType, null);
	case LuaValue.TNIL:
	return null;
	default:
	return value;
	}
	}
	}

	static {
	Coercion boolCoercion = new BoolCoercion();
	Coercion byteCoercion = new NumericCoercion(NumericCoercion.TARGET_TYPE_BYTE);
	Coercion charCoercion = new NumericCoercion(NumericCoercion.TARGET_TYPE_CHAR);
	Coercion shortCoercion = new NumericCoercion(NumericCoercion.TARGET_TYPE_SHORT);
	Coercion intCoercion = new NumericCoercion(NumericCoercion.TARGET_TYPE_INT);
	Coercion longCoercion = new NumericCoercion(NumericCoercion.TARGET_TYPE_LONG);
	Coercion floatCoercion = new NumericCoercion(NumericCoercion.TARGET_TYPE_FLOAT);
	Coercion doubleCoercion = new NumericCoercion(NumericCoercion.TARGET_TYPE_DOUBLE);
	Coercion stringCoercion = new StringCoercion(StringCoercion.TARGET_TYPE_STRING);
	Coercion bytesCoercion = new StringCoercion(StringCoercion.TARGET_TYPE_BYTES);

	COERCIONS.put( Boolean.TYPE, boolCoercion );
	COERCIONS.put( Boolean.class, boolCoercion );
	COERCIONS.put( Byte.TYPE, byteCoercion );
	COERCIONS.put( Byte.class, byteCoercion );
	COERCIONS.put( Character.TYPE, charCoercion );
	COERCIONS.put( Character.class, charCoercion );
	COERCIONS.put( Short.TYPE, shortCoercion );
	COERCIONS.put( Short.class, shortCoercion );
	COERCIONS.put( Integer.TYPE, intCoercion );
	COERCIONS.put( Integer.class, intCoercion );
	COERCIONS.put( Long.TYPE, longCoercion );
	COERCIONS.put( Long.class, longCoercion );
	COERCIONS.put( Float.TYPE, floatCoercion );
	COERCIONS.put( Float.class, floatCoercion );
	COERCIONS.put( Double.TYPE, doubleCoercion );
	COERCIONS.put( Double.class, doubleCoercion );
	COERCIONS.put( String.class, stringCoercion );
	COERCIONS.put( byte[].class, bytesCoercion );
	}

	static Coercion getCoercion(Class c) {
	Coercion co = (Coercion) COERCIONS.get( c );
	if ( co != null ) {
	return co;
	}
	if ( c.isArray() ) {
	Class typ = c.getComponentType();
	co = new ArrayCoercion(c.getComponentType());
	} else {
	co = new ObjectCoercion(c);
	}
	COERCIONS.put( c, co );
	return co;
	}
	}