/*
* Copyright (c) 1998-2011 Caucho Technology -- all rights reserved
*
* This file is part of Resin(R) Open Source
*
* Each copy or derived work must preserve the copyright notice and this
* notice unmodified.
*
* Resin Open Source is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Resin Open Source 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, or any warranty
* of NON-INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with Resin Open Source; if not, write to the
* Free SoftwareFoundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*/
package com.caucho.xpath.expr;
import com.caucho.xml.XmlUtil;
import com.caucho.xpath.Env;
import com.caucho.xpath.Expr;
import com.caucho.xpath.ExprEnvironment;
import com.caucho.xpath.XPathException;
import com.caucho.xpath.pattern.AbstractPattern;
import org.w3c.dom.Node;
import java.util.ArrayList;
import java.util.Iterator;
public class NumericExpr extends Expr {
private int _code;
private Expr _left;
private Expr _right;
private double _value;
private ArrayList<Expr> _args;
private AbstractPattern _axis;
private AbstractPattern _pattern;
public NumericExpr(int code, Expr left, Expr right)
{
_code = code;
_left = left;
_right = right;
}
public NumericExpr(int code, Expr expr)
{
_code = code;
_left = expr;
}
public NumericExpr(double value)
{
_code = CONST;
_value = value;
}
public NumericExpr(int code, ArrayList<Expr> args)
{
_code = code;
_args = args;
if (args.size() > 0)
_left = args.get(0);
if (args.size() > 1)
_right = args.get(1);
}
public NumericExpr(int code, AbstractPattern axis, AbstractPattern pattern)
{
_code = code;
_axis = axis;
_pattern = pattern;
}
public NumericExpr(int code, AbstractPattern listPattern)
{
_code = code;
if ((code == POSITION || code == LAST) && listPattern != null) {
_axis = listPattern.copyAxis();
_pattern = listPattern.copyPosition();
}
else
_pattern = listPattern;
}
public AbstractPattern getListContext()
{
switch (_code) {
case POSITION:
case LAST:
return _pattern;
default:
return null;
}
}
public boolean isNumber()
{
return true;
}
/**
* Returns true of the expression is constant.
*/
public boolean isConstant()
{
return _code == CONST;
}
/**
* Returns the expression's value.
*/
public double getValue()
{
return _value;
}
/**
* Evaluates to a variable.
*
* @param node the node to evaluate and use as a context.
* @param env the variable environment.
*
* @return a variable containing the value.
*/
public Var evalVar(Node node, ExprEnvironment env)
throws XPathException
{
double value = evalNumber(node, env);
return NumberVar.create(value);
}
/**
* Evaluates the expression as a number.
*
* @param node the node to evaluate and use as a context.
* @param env the variable environment.
*
* @return the numeric value
*/
public double evalNumber(Node node, ExprEnvironment env)
throws XPathException
{
switch (_code) {
case CONST:
return _value;
case NEG:
return - _left.evalNumber(node, env);
case ADD:
return (_left.evalNumber(node, env) + _right.evalNumber(node, env));
case SUB:
return (_left.evalNumber(node, env) - _right.evalNumber(node, env));
case MUL:
return (_left.evalNumber(node, env) * _right.evalNumber(node, env));
case DIV:
return (_left.evalNumber(node, env) / _right.evalNumber(node, env));
case QUO:
return (int) (_left.evalNumber(node, env) /
_right.evalNumber(node, env));
case MOD:
return (_left.evalNumber(node, env) % _right.evalNumber(node, env));
case NUMBER:
if (_left != null)
return _left.evalNumber(node, env);
else
return toDouble(node);
case FLOOR:
return Math.floor(_left.evalNumber(node, env));
case CEILING:
return Math.ceil(_left.evalNumber(node, env));
case ROUND:
return Math.rint(_left.evalNumber(node, env));
case SUM:
return sum(node, env);
case POSITION:
return position(node, env);
case LAST:
return last(node, env);
case COUNT:
return count(node, env);
case STRING_LENGTH:
String str = _left.evalString(node, env);
if (str == null)
return 0;
else
return str.length();
default:
throw new RuntimeException("unknown code: " + (char) _code);
}
}
/**
* Calculates the position of the node. For select patterns, the
* position will be given in the env variable.
*/
private int position(Node node, ExprEnvironment env)
throws XPathException
{
int position = env.getContextPosition();
if (position > 0)
return position;
if (_axis == null || ! (env instanceof Env))
throw new RuntimeException("position called with no context");
else if (_pattern == null)
return _axis.position(node, (Env) env, null);
else
return _axis.position(node, (Env) env, _pattern.copyPosition());
}
private int last(Node node, ExprEnvironment env)
throws XPathException
{
int size = env.getContextSize();
if (size > 0)
return size;
if (_axis == null || ! (env instanceof Env)) {
throw new RuntimeException("last called with no context");
}
else if (_pattern == null)
return _axis.position(node, (Env) env, null);
else
return _axis.count(node, (Env) env, _pattern.copyPosition());
}
/**
* Counts the nodes in a subpattern.
*/
private int count(Node node, ExprEnvironment env)
throws XPathException
{
int count = 0;
Iterator iter = _pattern.selectUnique(node, env);
while (iter.hasNext()) {
iter.next();
count++;
}
return count;
}
/**
* Returns the sum of all the node values.
*
* @param node the current node
* @param env the variable environment
*/
private double sum(Node node, ExprEnvironment env)
throws XPathException
{
double sum = 0;
Iterator iter = _pattern.selectUnique(node, env);
while (iter.hasNext()) {
Node subnode = (Node) iter.next();
String textValue = XmlUtil.textValue(subnode);
sum += stringToNumber(textValue);
}
return sum;
}
/**
* Evaluates the expression as a boolean.
*
* @param node the current node
* @param env the variable environment.
*
* @return the boolean representation of the number.
*/
public boolean evalBoolean(Node node, ExprEnvironment env)
throws XPathException
{
double value = evalNumber(node, env);
return value != 0.0 && ! Double.isNaN(value);
}
/**
* Evaluates the expression as a string.
*
* @param node the current node
* @param env the variable environment.
*
* @return the string representation of the number.
*/
public String evalString(Node node, ExprEnvironment env)
throws XPathException
{
double value = evalNumber(node, env);
if ((int) value == value)
return String.valueOf((int) value);
else
return String.valueOf(value);
}
/**
* Evaluates the expression as an object.
*
* @param node the current node
* @param env the variable environment.
*
* @return the Double representation of the number.
*/
public Object evalObject(Node node, ExprEnvironment env)
throws XPathException
{
return new Double(evalNumber(node, env));
}
public String toString()
{
switch (_code) {
case CONST: return String.valueOf(_value);
case NEG: return "-" + _left;
case ADD: return "(" + _left + " + " + _right + ")";
case SUB: return "(" + _left + " - " + _right + ")";
case MUL: return "(" + _left + " * " + _right + ")";
case DIV: return "(" + _left + " div " + _right + ")";
case QUO: return "(" + _left + " quo " + _right + ")";
case MOD: return "(" + _left + " mod " + _right + ")";
case NUMBER: return "number(" + _left + ")";
case SUM: return "sum(" + _pattern + ")";
case FLOOR: return "floor(" + _left + ")";
case CEILING: return "ceiling(" + _left + ")";
case ROUND: return "round(" + _left + ")";
case POSITION: return "position()";
case COUNT: return "count(" + _pattern + ")";
case LAST: return "last()";
case STRING_LENGTH:
return "string-length(" + _left + ")";
default: return super.toString();
}
}
}