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Maven 3 Plugin for processing JavaCC grammar files.
/* Copyright (c) 2006, Sun Microsystems, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the Sun Microsystems, Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.javacc.parser;
import java.util.Iterator;
/**
* A set of routines that walk down the Expansion tree in various ways.
*/
public final class ExpansionTreeWalker
{
private ExpansionTreeWalker ()
{}
/**
* Visits the nodes of the tree rooted at "node" in pre-order. i.e., it
* executes opObj.action first and then visits the children.
*/
static void preOrderWalk (final Expansion node, final TreeWalkerOp opObj)
{
opObj.action (node);
if (opObj.goDeeper (node))
{
if (node instanceof Choice)
{
for (final Iterator it = ((Choice) node).getChoices ().iterator (); it.hasNext ();)
{
preOrderWalk ((Expansion) it.next (), opObj);
}
}
else
if (node instanceof Sequence)
{
for (final Iterator it = ((Sequence) node).units.iterator (); it.hasNext ();)
{
preOrderWalk ((Expansion) it.next (), opObj);
}
}
else
if (node instanceof OneOrMore)
{
preOrderWalk (((OneOrMore) node).expansion, opObj);
}
else
if (node instanceof ZeroOrMore)
{
preOrderWalk (((ZeroOrMore) node).expansion, opObj);
}
else
if (node instanceof ZeroOrOne)
{
preOrderWalk (((ZeroOrOne) node).expansion, opObj);
}
else
if (node instanceof Lookahead)
{
final Expansion nested_e = ((Lookahead) node).getLaExpansion ();
if (!(nested_e instanceof Sequence && (Expansion) (((Sequence) nested_e).units.get (0)) == node))
{
preOrderWalk (nested_e, opObj);
}
}
else
if (node instanceof TryBlock)
{
preOrderWalk (((TryBlock) node).exp, opObj);
}
else
if (node instanceof RChoice)
{
for (final Iterator it = ((RChoice) node).getChoices ().iterator (); it.hasNext ();)
{
preOrderWalk ((Expansion) it.next (), opObj);
}
}
else
if (node instanceof RSequence)
{
for (final Iterator it = ((RSequence) node).units.iterator (); it.hasNext ();)
{
preOrderWalk ((Expansion) it.next (), opObj);
}
}
else
if (node instanceof ROneOrMore)
{
preOrderWalk (((ROneOrMore) node).regexpr, opObj);
}
else
if (node instanceof RZeroOrMore)
{
preOrderWalk (((RZeroOrMore) node).regexpr, opObj);
}
else
if (node instanceof RZeroOrOne)
{
preOrderWalk (((RZeroOrOne) node).regexpr, opObj);
}
else
if (node instanceof RRepetitionRange)
{
preOrderWalk (((RRepetitionRange) node).regexpr, opObj);
}
}
}
/**
* Visits the nodes of the tree rooted at "node" in post-order. i.e., it
* visits the children first and then executes opObj.action.
*/
static void postOrderWalk (final Expansion node, final TreeWalkerOp opObj)
{
if (opObj.goDeeper (node))
{
if (node instanceof Choice)
{
for (final Iterator it = ((Choice) node).getChoices ().iterator (); it.hasNext ();)
{
postOrderWalk ((Expansion) it.next (), opObj);
}
}
else
if (node instanceof Sequence)
{
for (final Iterator it = ((Sequence) node).units.iterator (); it.hasNext ();)
{
postOrderWalk ((Expansion) it.next (), opObj);
}
}
else
if (node instanceof OneOrMore)
{
postOrderWalk (((OneOrMore) node).expansion, opObj);
}
else
if (node instanceof ZeroOrMore)
{
postOrderWalk (((ZeroOrMore) node).expansion, opObj);
}
else
if (node instanceof ZeroOrOne)
{
postOrderWalk (((ZeroOrOne) node).expansion, opObj);
}
else
if (node instanceof Lookahead)
{
final Expansion nested_e = ((Lookahead) node).getLaExpansion ();
if (!(nested_e instanceof Sequence && (Expansion) (((Sequence) nested_e).units.get (0)) == node))
{
postOrderWalk (nested_e, opObj);
}
}
else
if (node instanceof TryBlock)
{
postOrderWalk (((TryBlock) node).exp, opObj);
}
else
if (node instanceof RChoice)
{
for (final Iterator it = ((RChoice) node).getChoices ().iterator (); it.hasNext ();)
{
postOrderWalk ((Expansion) it.next (), opObj);
}
}
else
if (node instanceof RSequence)
{
for (final Iterator it = ((RSequence) node).units.iterator (); it.hasNext ();)
{
postOrderWalk ((Expansion) it.next (), opObj);
}
}
else
if (node instanceof ROneOrMore)
{
postOrderWalk (((ROneOrMore) node).regexpr, opObj);
}
else
if (node instanceof RZeroOrMore)
{
postOrderWalk (((RZeroOrMore) node).regexpr, opObj);
}
else
if (node instanceof RZeroOrOne)
{
postOrderWalk (((RZeroOrOne) node).regexpr, opObj);
}
else
if (node instanceof RRepetitionRange)
{
postOrderWalk (((RRepetitionRange) node).regexpr, opObj);
}
}
opObj.action (node);
}
}