/*
* 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 org.exist.xquery.Constants;
import org.exist.xquery.Constants.Comparison;
import org.exist.xquery.ErrorCodes;
import org.exist.xquery.XPathException;
import java.text.Collator;
public class BooleanValue extends AtomicValue {
public final static BooleanValue TRUE = new BooleanValue(true);
public final static BooleanValue FALSE = new BooleanValue(false);
private final boolean value;
public BooleanValue(boolean bool) {
value = bool;
}
/**
* 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;
}
/* (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(ErrorCodes.XPTY0004,
"cannot convert 'xs:boolean(" + value + ")' to " + Type.getTypeName(requiredType));
}
}
@Override
public boolean compareTo(Collator collator, Comparison operator, AtomicValue other) throws XPathException {
if (Type.subTypeOf(other.getType(), Type.BOOLEAN)) {
boolean otherVal = ((BooleanValue) other).getValue();
switch (operator) {
case EQ:
return value == otherVal;
case NEQ:
return value != otherVal;
case LT:
return (!value) && otherVal;
case LTEQ:
return value == otherVal || (!value) && otherVal;
case GT:
return value && (!otherVal);
case GTEQ:
return value == otherVal || value && (!otherVal);
default:
throw new XPathException("Type error: cannot apply this operator to a boolean value");
}
}
throw new XPathException(ErrorCodes.XPTY0004,
"cannot convert 'xs:boolean(" + value + ")' to " + Type.getTypeName(other.getType()));
}
public int compareTo(Collator collator, AtomicValue other) throws XPathException {
final 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) {
final 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)
*/
@Override
public <T> T toJavaObject(final Class<T> target) throws XPathException {
if (target.isAssignableFrom(BooleanValue.class)) {
return (T) this;
} else if (target == Boolean.class || target == boolean.class || target == Object.class) {
return (T) Boolean.valueOf(value);
} else if (target == String.class || target == CharSequence.class) {
final StringValue v = (StringValue) convertTo(Type.STRING);
return (T) 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;
}
}
@Override
public boolean equals(Object obj) {
if (obj instanceof BooleanValue) {
return value == ((BooleanValue) obj).value;
}
return false;
}
}