1    :  // Copyright 2011 Google Inc. All Rights Reserved.
   2    :  //
   3    :  // Licensed under the Apache License, Version 2.0 (the "License");
   4    :  // you may not use this file except in compliance with the License.
   5    :  // You may obtain a copy of the License at
   6    :  //
   7    :  //     http://www.apache.org/licenses/LICENSE-2.0
   8    :  //
   9    :  // Unless required by applicable law or agreed to in writing, software
  10    :  // distributed under the License is distributed on an "AS IS" BASIS,
  11    :  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12    :  // See the License for the specific language governing permissions and
  13    :  // limitations under the License.
  14    :  //
  15    :  // A function for iterating over a changing BlockGraph. Intended for use by
  16    :  // BlockGraphTransforms.
  17    :  
  18    :  #ifndef SYZYGY_BLOCK_GRAPH_ITERATE_H_
  19    :  #define SYZYGY_BLOCK_GRAPH_ITERATE_H_
  20    :  
  21    :  #include "base/callback.h"
  22    :  #include "syzygy/block_graph/block_graph.h"
  23    :  
  24  m :  namespace block_graph {
  25    :  
  26    :  // The type of callback used by the IterateBlockGraph function.
  27  m :  typedef base::Callback<bool(BlockGraph* block_graph,
  28  m :                              BlockGraph::Block*)> IterationCallback;
  29    :  
  30    :  // This is an iterating primitive that transforms can make use of. It takes
  31    :  // care of iterating in such a manner that the callback function may modify the
  32    :  // block-graph being iterating without worry.
  33    :  //
  34    :  // The callback has freedom to modify any block in the block-graph, and to add
  35    :  // any number of blocks to the block-graph. It is constrained to be allowed
  36    :  // to delete only the current block being handled by the callback.
  37    :  //
  38    :  // The iteration will only visit those blocks that were pre-existing in the
  39    :  // BlockGraph. That is, if the callback causes new blocks to be generated those
  40    :  // blocks will never be visited and passed to the callback.
  41    :  //
  42    :  // @param callback the callback to invoke for each pre-existing block in the
  43    :  //     block graph.
  44    :  // @param block_graph the block graph that is to be iterated. This is non
  45    :  //     const as the callback function may modify the block graph as the
  46    :  //     iteration proceeds.
  47  m :  bool IterateBlockGraph(const IterationCallback& callback,
  48  m :                         BlockGraph* block_graph);
  49    :  
  50  m :  }  // namespace block_graph
  51    :  
  52    :  #endif  // SYZYGY_BLOCK_GRAPH_ITERATE_H_