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package org.luaj.vm2.lib.jse;
import java.lang.reflect.Array;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import org.luaj.vm2.LuaError;
import org.luaj.vm2.LuaString;
import org.luaj.vm2.LuaTable;
import org.luaj.vm2.LuaValue;
import org.luaj.vm2.Varargs;
/**
* Helper class to coerce values from lua to Java within the luajava library.
*
* This class is primarily used by the {@link LuajavaLib},
* but can also be used directly when working with Java/lua bindings.
*
* To coerce to specific Java values, generally the {@code toType()} methods
* on {@link LuaValue} may be used:
*
* - {@link LuaValue#toboolean()}
* - {@link LuaValue#tobyte()}
* - {@link LuaValue#tochar()}
* - {@link LuaValue#toshort()}
* - {@link LuaValue#toint()}
* - {@link LuaValue#tofloat()}
* - {@link LuaValue#todouble()}
* - {@link LuaValue#tojstring()}
* - {@link LuaValue#touserdata()}
* - {@link LuaValue#touserdata(Class)}
*
*
* 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 ) {
if ( value.isint() ) {
switch ( targetType ) {
case TARGET_TYPE_BYTE: {
int i = value.toint();
return (i==(byte)i)? 0: SCORE_WRONG_TYPE;
}
case TARGET_TYPE_CHAR: {
int i = value.toint();
return (i==(byte)i)? 1: (i==(char)i)? 0: SCORE_WRONG_TYPE;
}
case TARGET_TYPE_SHORT: {
int i = value.toint();
return (i==(byte)i)? 1: (i==(short)i)? 0: SCORE_WRONG_TYPE;
}
case TARGET_TYPE_INT: {
int i = value.toint();
return (i==(byte)i)? 2: ((i==(char)i) || (i==(short)i))? 1: 0;
}
case TARGET_TYPE_FLOAT: return 1;
case TARGET_TYPE_LONG: return 1;
case TARGET_TYPE_DOUBLE: return 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 (d==(long)d)? 0: SCORE_WRONG_TYPE;
}
case TARGET_TYPE_FLOAT: {
double d = value.todouble();
return (d==(float)d)? 0: SCORE_WRONG_TYPE;
}
case TARGET_TYPE_DOUBLE: {
double d = value.todouble();
return ((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