File indexing completed on 2024-04-21 04:36:15

 /* 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);
 
   void visitNode(Model::Node *node) override;
   void visitAlternative(Model::AlternativeItem *node) override;
   void visitCons(Model::ConsItem *node) override;
   
   void copy(Model::Node *from, Model::Node *to) override { 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