/**
* This file Copyright (c) 2005-2008 Aptana, Inc. This program is
* dual-licensed under both the Aptana Public License and the GNU General
* Public license. You may elect to use one or the other of these licenses.
*
* This program is distributed in the hope that it will be useful, but
* AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
* NONINFRINGEMENT. Redistribution, except as permitted by whichever of
* the GPL or APL you select, is prohibited.
*
* 1. For the GPL license (GPL), you can redistribute and/or modify this
* program under the terms of the GNU General Public License,
* Version 3, as published by the Free Software Foundation. You should
* have received a copy of the GNU General Public License, Version 3 along
* with this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Aptana provides a special exception to allow redistribution of this file
* with certain other free and open source software ("FOSS") code and certain additional terms
* pursuant to Section 7 of the GPL. You may view the exception and these
* terms on the web at http://www.aptana.com/legal/gpl/.
*
* 2. For the Aptana Public License (APL), this program and the
* accompanying materials are made available under the terms of the APL
* v1.0 which accompanies this distribution, and is available at
* http://www.aptana.com/legal/apl/.
*
* You may view the GPL, Aptana's exception and additional terms, and the
* APL in the file titled license.html at the root of the corresponding
* plugin containing this source file.
*
* Any modifications to this file must keep this entire header intact.
*/
package com.aptana.ide.parsing.bnf;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.aptana.ide.parsing.bnf.nodes.GrammarNode;
import com.aptana.ide.parsing.bnf.nodes.IGrammarNode;
import com.aptana.ide.parsing.bnf.nodes.ProductionNode;
/**
* @author Kevin Lindsey
*/
public class State
{
private static final Action ERROR_ACTION = new Action(ActionType.ERROR, -1);
private GrammarNode _grammar;
private List<Item> _items;
private Map<String,Action> _transitions;
private int _index;
/**
* State
*
* @param grammar
*/
private State(GrammarNode grammar)
{
this._grammar = grammar;
this._items = new ArrayList<Item>();
this._index = -1;
this._transitions = new HashMap<String,Action>();
}
/**
* State
*
* @param grammar
* @param item
*/
public State(GrammarNode grammar, Item item)
{
this(grammar);
this._items.add(item);
this.buildSet();
}
/**
* addAccept
*
* @param name
*/
public void addAccept(String name)
{
Action action = new Action(ActionType.ACCEPT, -1);
if (this._transitions.containsKey(name))
{
System.out.print("Accept state " + action + " not added because "); //$NON-NLS-1$ //$NON-NLS-2$
System.out.println(name + " is already defined as " + this._transitions.get(name) + ". "); //$NON-NLS-1$ //$NON-NLS-2$
System.out.println(" " + this.getIndex() + ": " + this.getHashKey()); //$NON-NLS-1$ //$NON-NLS-2$
}
else
{
this._transitions.put(name, action);
}
}
/**
* addError
*
* @param name
* @param errorNumber
*/
public void addError(String name, int errorNumber)
{
Action action = new Action(ActionType.ERROR, errorNumber);
if (this._transitions.containsKey(name))
{
System.out.print("Error state " + action + " not added because. "); //$NON-NLS-1$ //$NON-NLS-2$
System.out.println(name + " is already defined as " + this._transitions.get(name) + ". "); //$NON-NLS-1$ //$NON-NLS-2$
System.out.println(" " + this.getIndex() + ": " + this.getHashKey()); //$NON-NLS-1$ //$NON-NLS-2$
}
else
{
this._transitions.put(name, action);
}
}
/**
* addGoto
*
* @param name
* @param newState
*/
public void addGoto(String name, int newState)
{
Action action = new Action(ActionType.GOTO, newState);
if (this._transitions.containsKey(name))
{
System.out.print("Goto state " + action + " not added because "); //$NON-NLS-1$ //$NON-NLS-2$
System.out.println(name + " is already defined as " + this._transitions.get(name) + ". "); //$NON-NLS-1$ //$NON-NLS-2$
System.out.println(" " + this.getIndex() + ": " + this.getHashKey()); //$NON-NLS-1$ //$NON-NLS-2$
}
else
{
this._transitions.put(name, action);
}
}
/**
* addReduce
*
* @param name
* @param newState
*/
public void addReduce(String name, int newState)
{
Action action = new Action(ActionType.REDUCE, newState);
if (this._transitions.containsKey(name))
{
// System.out.print("Reduce state " + action + " not added because ");
// System.out.println(name + " is already defined as " + this._transitions.get(name) + ". ");
// System.out.println(" " + this.getIndex() + ": " + this.getHashKey());
}
else
{
this._transitions.put(name, action);
}
}
/**
* addShift
*
* @param name
* @param newState
*/
public void addShift(String name, int newState)
{
Action action = new Action(ActionType.SHIFT, newState);
if (this._transitions.containsKey(name))
{
System.out.print("Shift state " + action + " not added because "); //$NON-NLS-1$ //$NON-NLS-2$
System.out.println(name + " is already defined as " + this._transitions.get(name)); //$NON-NLS-1$
System.out.println(" " + this.getIndex() + ": " + this.getHashKey()); //$NON-NLS-1$ //$NON-NLS-2$
}
else
{
this._transitions.put(name, action);
}
}
/**
* buildSet
*
* @param set
* @param item
*/
private void buildSet()
{
int index = 0;
while (index < this._items.size())
{
Item currentItem = this._items.get(index);
if (currentItem.isAtNonTerminal() && currentItem.isCompletedItem() == false)
{
IGrammarNode current = currentItem.getCurrentNode();
String name = current.getName();
ProductionNode[] productions = this._grammar.getProductionsByName(name);
for (int i = 0; i < productions.length; i++)
{
Item candidate = new Item(productions[i]);
if (this._items.contains(candidate) == false)
{
this._items.add(candidate);
}
}
}
index++;
}
}
/**
* getAction
*
* @param name
* @return
*/
public Action getAction(String name)
{
Action result = this._transitions.get(name);
if (result == null)
{
result = ERROR_ACTION;
}
return result;
}
/**
* getHashKey
*
* @return
*/
private String getHashKey()
{
StringBuffer buffer = new StringBuffer();
for (int i = 0; i < this._items.size(); i++)
{
Item item = this._items.get(i);
if (i > 0)
{
buffer.append(", "); //$NON-NLS-1$
}
buffer.append(item.toString());
}
return buffer.toString();
}
/**
* getIndex
*
* @return
*/
public int getIndex()
{
return this._index;
}
/**
* getItems
*
* @return
*/
public Item[] getItems()
{
return this._items.toArray(new Item[this._items.size()]);
}
/**
* Generate a list of all transitions out of this state. The resulting
* list will not contain duplicates
*
* @return
*/
public List<IGrammarNode> getTransitionInputs()
{
List<IGrammarNode> result = new ArrayList<IGrammarNode>();
for (Item item : this._items)
{
IGrammarNode currentNode = item.getCurrentNode();
if (currentNode != null && result.contains(currentNode) == false)
{
result.add(currentNode);
}
}
return result;
}
/**
* getTransitionState
*
* @param input
* @return
*/
public State getTransitionState(IGrammarNode input, Map<String,State> stateMap)
{
State state = new State(this._grammar);
for (Item item : this._items)
{
if (item.isCompletedItem() == false && item.getCurrentNode().equals(input))
{
// make a clone of the item so each can advance independently
// of the other
Item newItem = new Item(item);
// advance over matching input
newItem.advance();
// add cloned item to resulting states item set
state._items.add(newItem);
}
}
// find e-closures
state.buildSet();
// NOTE: this should never be null
if (stateMap != null)
{
// get the state's unique name
String name = state.getHashKey();
// so we can see if we have one for this state already
if (stateMap.containsKey(name))
{
// we do, so use the state we already have
state = stateMap.get(name);
}
else
{
// otherwise, store in the cache for possible future references
stateMap.put(name, state);
}
}
return state;
}
/**
* setIndex
*
* @param index
*/
public void setIndex(int index)
{
this._index = index;
}
/**
* toString
*/
public String toString()
{
StringWriter sw = new StringWriter();
PrintWriter writer = new PrintWriter(sw);
for (int i = 0; i < this._items.size(); i++)
{
writer.println(this._items.get(i).toString());
}
return sw.toString();
}
}