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/* This file is part of kdev-pg-qt
Copyright (C) 2005 Roberto Raggi <roberto@kdevelop.org>
Copyright (C) 2010 Jonathan Schmidt-Dominé <devel@the-user.org>
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 library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
#ifndef KDEV_PG_FIRST_H
#define KDEV_PG_FIRST_H
#include "kdev-pg.h"
#include "kdev-pg-bnf-visitor.h"
#include <QSet>
namespace KDevPG
{
/**
* Adds first-sets for terminals and zeros.
*/
void initializeFirst ();
/**
* Recursively merge first-sets.
*/
class NextFirst: protected BnfVisitor
{
public:
NextFirst(bool &changed);
void operator ()(Model::Node *node);
protected:
bool blockZeroMerge(bool block);
void merge(Model::Node *__dest, Model::Node *__source, int K = 1);
virtual void visitNode(Model::Node *node);
virtual void visitAlternative(Model::AlternativeItem *node);
virtual void visitCons(Model::ConsItem *node);
virtual void copy(Model::Node *from, Model::Node *to) { merge(to, from); }
private:
bool mMergeZeroBlocked;
bool &mChanged;
QSet<Model::Node*> mVisited;
};
/**
* This method computes the first-set for all symbols.
* The algorithm: The function starts with InitializeFirst. As long as possible NextFirst will merge first-sets.
*/
void computeFirst();
}
#endif // KDEV_PG_FIRST_H
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