lumiera_/src/lib/diff/diff.cpp

/*
  Diff  -  common helpers for the diff handling framework

  Copyright (C)         Lumiera.org
    2015,               Hermann Vosseler <Ichthyostega@web.de>

  This program 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.

  This program 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 General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

* *****************************************************/


/** @file diff.cpp
 ** Diff handling framework support code.
 ** This translation unit emits code used by the implementation
 ** of generic functionality
 ** 
 ** @see diff-language.hpp
 ** 
 */


#include "lib/error.hpp"
#include "lib/diff/diff-language.hpp"
#include "lib/diff/gen-node.hpp"


namespace lib {
namespace diff{
  
  LUMIERA_ERROR_DEFINE(DIFF_CONFLICT, "Collision in diff application: contents of target not as expected.");
  
  /* symbolic marker ID references
   * used within the tree diff language
   * to mark specific scopes
   */
  Ref Ref::END    ("_END_");
  Ref Ref::THIS   ("_THIS_");
  Ref Ref::CHILD  ("_CHILD_");
  Ref Ref::ATTRIBS("_ATTRIBS_");

  
  /** Implementation of content equality test */
  bool
  DataCap::operator== (DataCap const& o)  const
  {
    class EqualityTest
      : public Variant<DataValues>::Visitor
      {
        DataCap const& o_;
        bool isEqual_;

#define DERIVE_EQUALITY(_TY_) \
        virtual void handle  (_TY_& val) override { isEqual_ = (o_.get<_TY_>() == val); }
        
        DERIVE_EQUALITY (int)
        DERIVE_EQUALITY (int64_t)
        DERIVE_EQUALITY (short)
        DERIVE_EQUALITY (char)
        DERIVE_EQUALITY (bool)
        DERIVE_EQUALITY (double)
        DERIVE_EQUALITY (string)
        DERIVE_EQUALITY (time::Time)
        DERIVE_EQUALITY (time::Offset)
        DERIVE_EQUALITY (time::Duration)
        DERIVE_EQUALITY (time::TimeSpan)
        DERIVE_EQUALITY (hash::LuidH)
        DERIVE_EQUALITY (RecRef)
        DERIVE_EQUALITY (Rec)
        
      public:
        EqualityTest(DataCap const& o)
          : o_(o)
          , isEqual_(false)
          { }
        
        operator bool() { return isEqual_; }
      };
    
    EqualityTest visitor(o);
    unConst(this)->accept(visitor);
    return visitor;
  }

}} // namespace lib::diff