/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-06, Wolfgang M. Meier (meier@ifs.tu-darmstadt.de)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This library 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 Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* $Id$
*/
package org.exist.xquery.value;
import java.text.Collator;
import org.exist.xquery.Constants;
import org.exist.xquery.XPathException;
public class BooleanValue extends AtomicValue {
public final static BooleanValue TRUE = new BooleanValue(true);
public final static BooleanValue FALSE = new BooleanValue(false);
private boolean value;
/**
* Returns one of the static fields TRUE or FALSE depending on
* the value of the parameter.
*
* @param bool
*/
public final static BooleanValue valueOf(boolean bool) {
return bool ? TRUE : FALSE;
}
public BooleanValue(boolean bool) {
value = bool;
}
/* (non-Javadoc)
* @see org.exist.xquery.value.AtomicValue#getType()
*/
public int getType() {
return Type.BOOLEAN;
}
/* (non-Javadoc)
* @see org.exist.xquery.value.Item#getStringValue()
*/
public String getStringValue() throws XPathException {
return value ? "true" : "false";
}
/* (non-Javadoc)
* @see org.exist.xquery.value.AtomicValue#convertTo(int)
*/
public AtomicValue convertTo(int requiredType) throws XPathException {
switch (requiredType) {
case Type.BOOLEAN :
case Type.ATOMIC :
case Type.ITEM :
return this;
case Type.NUMBER :
case Type.INTEGER :
return new IntegerValue(value ? 1 : 0);
case Type.DECIMAL :
return new DecimalValue(value ? 1 : 0);
case Type.FLOAT :
return new FloatValue(value ? 1 : 0);
case Type.DOUBLE :
return new DoubleValue(value ? 1 : 0);
case Type.STRING :
return new StringValue(getStringValue());
case Type.UNTYPED_ATOMIC :
return new UntypedAtomicValue(getStringValue());
default :
throw new XPathException(
"XPTY0004: cannot convert 'xs:boolean(" + value + ")' to " + Type.getTypeName(requiredType));
}
}
/* (non-Javadoc)
* @see org.exist.xquery.value.AtomicValue#compareTo(int, org.exist.xquery.value.AtomicValue)
*/
public boolean compareTo(Collator collator, int operator, AtomicValue other) throws XPathException {
if (Type.subTypeOf(other.getType(), Type.BOOLEAN)) {
boolean otherVal = ((BooleanValue) other).getValue();
switch (operator) {
case Constants.EQ :
return value == otherVal;
case Constants.NEQ :
return value != otherVal;
case Constants.LT:
return (!value) && otherVal;
case Constants.LTEQ:
return value == otherVal || (!value) && otherVal;
case Constants.GT:
return value && (!otherVal);
case Constants.GTEQ:
return value == otherVal || value && (!otherVal);
default :
throw new XPathException("Type error: cannot apply this operator to a boolean value");
}
}
throw new XPathException("XPTY0004: cannot convert 'xs:boolean(" + value + ")' to " + Type.getTypeName(other.getType()));
}
public int compareTo(Collator collator, AtomicValue other) throws XPathException {
boolean otherVal = other.effectiveBooleanValue();
if (otherVal == value)
return Constants.EQUAL;
else if (value)
return Constants.SUPERIOR;
else
return Constants.INFERIOR;
}
/* (non-Javadoc)
* @see org.exist.xquery.value.AtomicValue#effectiveBooleanValue()
*/
public boolean effectiveBooleanValue() throws XPathException {
return value;
}
public boolean getValue() {
return value;
}
/* (non-Javadoc)
* @see org.exist.xquery.value.AtomicValue#max(org.exist.xquery.value.AtomicValue)
*/
public AtomicValue max(Collator collator, AtomicValue other) throws XPathException {
if (other.getType() == Type.BOOLEAN) {
boolean otherValue = ((BooleanValue) other).value;
return value && (!otherValue) ? this : other;
} else
throw new XPathException(
"Invalid argument to aggregate function: expected boolean, got: "
+ Type.getTypeName(other.getType()));
}
public AtomicValue min(Collator collator, AtomicValue other) throws XPathException {
if (other.getType() == Type.BOOLEAN) {
boolean otherValue = ((BooleanValue) other).value;
return (!value) && otherValue ? this : other;
} else
throw new XPathException(
"Invalid argument to aggregate function: expected boolean, got: "
+ Type.getTypeName(other.getType()));
}
/* (non-Javadoc)
* @see org.exist.xquery.value.Item#conversionPreference(java.lang.Class)
*/
public int conversionPreference(Class javaClass) {
if(javaClass.isAssignableFrom(BooleanValue.class)) return 0;
if(javaClass == Boolean.class || javaClass == boolean.class) return 1;
if(javaClass == Object.class) return 20;
if(javaClass == String.class || javaClass == CharSequence.class) return 2;
return Integer.MAX_VALUE;
}
/* (non-Javadoc)
* @see org.exist.xquery.value.Item#toJavaObject(java.lang.Class)
*/
public Object toJavaObject(Class target) throws XPathException {
if(target.isAssignableFrom(BooleanValue.class))
return this;
else if(target == Boolean.class || target == boolean.class || target == Object.class)
return Boolean.valueOf(value);
else if(target == String.class || target == CharSequence.class) {
StringValue v = (StringValue)convertTo(Type.STRING);
return v.value;
}
throw new XPathException("cannot convert value of type " + Type.getTypeName(getType()) +
" to Java object of type " + target.getName());
}
/* (non-Javadoc)
* @see java.lang.Comparable#compareTo(java.lang.Object)
*/
public int compareTo(Object o) {
final AtomicValue other = (AtomicValue)o;
if(Type.subTypeOf(other.getType(), Type.BOOLEAN)) {
if(value == ((BooleanValue)other).value)
return Constants.EQUAL;
else if(value)
return Constants.SUPERIOR;
else
return Constants.INFERIOR;
} else
return getType() < other.getType() ? Constants.INFERIOR : Constants.SUPERIOR;
}
}