traversalutilities.hh

// -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
// vi: set et ts=4 sw=2 sts=2:
// SPDX-FileCopyrightInfo: Copyright © DUNE Project contributors, see file LICENSE.md in module root
// SPDX-License-Identifier: LGPL-3.0-or-later OR LicenseRef-GPL-2.0-only-with-PDELab-exception
 
#ifndef DUNE_TYPETREE_TRAVERSALUTILITIES_HH
#define DUNE_TYPETREE_TRAVERSALUTILITIES_HH
 
#include <dune/typetree/traversal.hh>
 
namespace Dune {
  namespace TypeTree {
 
    namespace {
 
 
      template<typename F, typename R, typename ResultType>
      struct LeafReductionVisitor
        : public TypeTree::TreeVisitor
      {
 
        static const TreePathType::Type treePathType = TreePathType::dynamic;
 
        template<typename Node, typename TreePath>
        void leaf(const Node& node, TreePath treePath)
        {
          _value = _reduction(_value,_functor(node,treePath));
        }
 
        LeafReductionVisitor(F functor, R reduction, ResultType startValue)
          : _functor(functor)
          , _reduction(reduction)
          , _value(startValue)
        {}
 
        ResultType result() { return _value; }
 
        F _functor;
        R _reduction;
        ResultType _value;
 
      };
 
    } // anonymous namespace
 
 
    template<typename ResultType, typename Tree, typename F, typename R>
    ResultType reduceOverLeafs(const Tree& tree, F functor, R reduction, ResultType startValue)
    {
      LeafReductionVisitor<F,R,ResultType> visitor(functor,reduction,startValue);
      TypeTree::applyToTree(tree,visitor);
      return visitor.result();
    }
 
 
  } // namespace TypeTree
} //namespace Dune
 
#endif // DUNE_TYPETREE_TRAVERSALUTILITIES_HH