/*
* 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 Software Foundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*/
package com.caucho.relaxng.program;
import com.caucho.relaxng.RelaxException;
import com.caucho.util.CharBuffer;
import com.caucho.util.L10N;
import com.caucho.xml.QName;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
/**
* Generates programs from patterns.
*/
public class ChoiceItem extends Item {
protected final static L10N L = new L10N(ChoiceItem.class);
private ArrayList<Item> _items = new ArrayList<Item>();
private boolean _allowEmpty = false;
public ChoiceItem()
{
}
public static Item create(Item left, Item right)
{
ChoiceItem choice = new ChoiceItem();
choice.addItem(left);
choice.addItem(right);
return choice.getMin();
}
public void addItem(Item item)
{
if (item == null)
return;
else if (item instanceof EmptyItem) {
_allowEmpty = true;
return;
}
else if (item instanceof ChoiceItem) {
ChoiceItem choice = (ChoiceItem) item;
if (choice._allowEmpty)
_allowEmpty = true;
for (int i = 0; i < choice._items.size(); i++)
addItem(choice._items.get(i));
return;
}
for (int i = 0; i < _items.size(); i++) {
Item subItem = _items.get(i);
if (item.equals(subItem))
return;
if (item instanceof InElementItem &&
subItem instanceof InElementItem) {
InElementItem elt1 = (InElementItem) item;
InElementItem elt2 = (InElementItem) subItem;
if (elt1.getElementItem().equals(elt2.getElementItem())) {
subItem = InElementItem.create(elt1.getElementItem(),
create(elt1.getContinuationItem(),
elt2.getContinuationItem()));
_items.remove(i);
addItem(subItem);
return;
}
}
if (item instanceof GroupItem
&& subItem instanceof GroupItem) {
GroupItem group1 = (GroupItem) item;
GroupItem group2 = (GroupItem) subItem;
if (group1.getFirst().equals(group2.getFirst())) {
subItem = GroupItem.create(group1.getFirst(),
create(group1.getSecond(),
group2.getSecond()));
_items.remove(i);
addItem(subItem);
return;
}
}
}
_items.add(item);
}
public Item getMin()
{
if (! _allowEmpty && _items.size() == 0)
return null;
else if (_allowEmpty && _items.size() == 0)
return EmptyItem.create();
else if (_items.size() == 1
&& (! _allowEmpty || _items.get(0).allowEmpty()))
return _items.get(0);
else
return this;
}
/**
* Returns the first set, the set of element names possible.
*/
public void firstSet(HashSet<QName> set)
{
for (int i = 0; i < _items.size(); i++)
_items.get(i).firstSet(set);
}
/**
* Returns the first set, the set of element names possible.
*/
public void requiredFirstSet(HashSet<QName> set)
{
if (allowEmpty())
return;
for (int i = 0; i < _items.size(); i++)
_items.get(i).requiredFirstSet(set);
}
/**
* Allows empty if any item allows empty.
*/
public boolean allowEmpty()
{
if (_allowEmpty)
return true;
for (int i = 0; i < _items.size(); i++)
if (_items.get(i).allowEmpty())
return true;
return false;
}
/**
* Interleaves a continuation.
*/
public Item interleaveContinuation(Item cont)
{
ChoiceItem item = new ChoiceItem();
for (int i = 0; i < _items.size(); i++)
item.addItem(_items.get(i).interleaveContinuation(cont));
return item.getMin();
}
/**
* Adds an inElement continuation.
*/
public Item inElementContinuation(Item cont)
{
ChoiceItem item = new ChoiceItem();
for (int i = 0; i < _items.size(); i++)
item.addItem(_items.get(i).inElementContinuation(cont));
return item.getMin();
}
/**
* Adds a group continuation.
*/
public Item groupContinuation(Item cont)
{
ChoiceItem item = new ChoiceItem();
for (int i = 0; i < _items.size(); i++)
item.addItem(_items.get(i).groupContinuation(cont));
return item.getMin();
}
/**
* Return all possible child items or null
*/
public Iterator<Item> getItemsIterator()
{
if ( _items.size() == 0 )
return emptyItemIterator();
else
return _items.iterator();
}
/**
* Returns the next item on the match.
*/
public Item startElement(QName name)
throws RelaxException
{
Item result = null;
ChoiceItem choice = null;
for (int i = 0; i < _items.size(); i++) {
Item next = _items.get(i).startElement(name);
if (next == null) {
}
else if (result == null)
result = next;
else {
if (choice == null) {
choice = new ChoiceItem();
choice.addItem(result);
}
choice.addItem(next);
}
}
if (choice != null)
return choice.getMin();
else
return result;
}
/**
* Returns the first set, the set of attribute names possible.
*/
public void attributeSet(HashSet<QName> set)
{
for (int i = 0; i < _items.size(); i++)
_items.get(i).attributeSet(set);
}
/**
* Returns true if the attribute is allowed.
*
* @param name the name of the attribute
* @param value the value of the attribute
*
* @return true if the attribute is allowed
*/
public boolean allowAttribute(QName name, String value)
throws RelaxException
{
for (int i = _items.size() - 1; i >= 0; i--)
if (_items.get(i).allowAttribute(name, value))
return true;
return false;
}
/**
* Sets an attribute.
*
* @param name the name of the attribute
* @param value the value of the attribute
*
* @return the program for handling the element
*/
public Item setAttribute(QName name, String value)
throws RelaxException
{
if (! allowAttribute(name, value))
return this;
ChoiceItem choice = new ChoiceItem();
if (_allowEmpty)
choice.addItem(EmptyItem.create());
for (int i = _items.size() - 1; i >= 0; i--) {
Item next = _items.get(i).setAttribute(name, value);
if (next == null)
return null;
choice.addItem(next);
}
return choice.getMin();
}
/**
* Returns true if the item can match empty.
*/
public Item attributeEnd()
{
ChoiceItem choice = new ChoiceItem();
if (_allowEmpty)
choice._allowEmpty = true;
for (int i = _items.size() - 1; i >= 0; i--) {
Item next = _items.get(i).attributeEnd();
if (next == null)
continue;
choice.addItem(next);
}
if (choice.equals(this))
return this;
else
return choice.getMin();
}
/**
* Returns the next item on the match.
*/
@Override
public Item text(CharSequence data)
throws RelaxException
{
Item result = null;
ChoiceItem choice = null;
for (int i = 0; i < _items.size(); i++) {
Item next = _items.get(i).text(data);
if (next == null) {
}
else if (result == null)
result = next;
else {
if (choice == null) {
choice = new ChoiceItem();
choice.addItem(result);
}
choice.addItem(next);
}
}
if (choice != null)
return choice.getMin();
else
return result;
}
/**
* Returns the next item when the element closes
*/
public Item endElement()
throws RelaxException
{
ChoiceItem choice = new ChoiceItem();
if (_allowEmpty)
choice._allowEmpty = true;
for (int i = _items.size() - 1; i >= 0; i--) {
Item next = _items.get(i).endElement();
if (next == null)
continue;
choice.addItem(next);
}
if (choice.equals(this))
return this;
else
return choice.getMin();
}
/**
* Returns the hash code for the empty item.
*/
public int hashCode()
{
int hash = 37;
for (int i = 0; i < _items.size(); i++)
hash += _items.get(i).hashCode();
return hash;
}
/**
* Returns true if the object is an empty item.
*/
public boolean equals(Object o)
{
if (this == o)
return true;
if (! (o instanceof ChoiceItem))
return false;
ChoiceItem choice = (ChoiceItem) o;
return isSubset(choice) && choice.isSubset(this);
}
private boolean isSubset(ChoiceItem item)
{
if (_items.size() != item._items.size())
return false;
for (int i = 0; i < _items.size(); i++) {
Item subItem = _items.get(i);
if (! item._items.contains(subItem))
return false;
}
return true;
}
/**
* Returns true if the element is allowed somewhere in the item.
* allowsElement is used for error messages to give more information
* in cases of order dependency.
*
* @param name the name of the element
*
* @return true if the element is allowed somewhere
*/
public boolean allowsElement(QName name)
{
for (int i = 0; i < _items.size(); i++) {
Item subItem = _items.get(i);
if (subItem.allowsElement(name))
return true;
}
return false;
}
/**
* Returns the pretty printed syntax.
*/
public String toSyntaxDescription(int depth)
{
CharBuffer cb = CharBuffer.allocate();
if (_items.size() > 1)
cb.append("(");
boolean isSimple = true;
for (int i = 0; i < _items.size(); i++) {
Item item = _items.get(i);
if (! item.isSimpleSyntax())
isSimple = false;
if (i == 0) {
if (! isSimple)
cb.append(" ");
}
else if (isSimple) {
cb.append(" | ");
}
else {
addSyntaxNewline(cb, depth);
cb.append("| ");
}
cb.append(item.toSyntaxDescription(depth + 2));
}
if (_items.size() > 1)
cb.append(')');
if (_allowEmpty)
cb.append('?');
return cb.close();
}
/**
* Returns true for an element with simple syntax.
*/
protected boolean isSimpleSyntax()
{
return (_items.size() == 1) && _items.get(0).isSimpleSyntax();
}
public String toString()
{
StringBuffer sb = new StringBuffer();
sb.append("ChoiceItem[");
for (int i = 0; i < _items.size(); i++) {
if (i != 0)
sb.append(", ");
sb.append(_items.get(i));
}
if (_allowEmpty) {
sb.append(",empty");
}
sb.append("]");
return sb.toString();
}
}