Readme update

README.md

@@ -7,6 +7,10 @@ For example usage see `demo.py`.
 
 My use case: automated refactoring of `.proto` files.
 
+* Benefit of this project is support for easy refactoring of the protocol buffers files. From the parse
+result one can simply determine position of a particular lexical unit in the source text and replace it.
+* The visitor pattern is used for processing a parse tree.
+
 ## Dependency
 * This project has only one dependency, [PLY] [1].
 * `ply/` subdirectory is present in this repo for demonstration purposes and completeness only. If you intend to use this project, prefer better original
@@ -19,12 +23,25 @@ If you find a bug, please feel free to submit a pull request or file an issue.
 ## Bugs
 * `Oneof` is not implemented yet. 
 
+## Demo 1
+* `demo.py`
+* The first demo file shows simple parsing of the example protocol buffer message. It produces a parse tree of this simple
+examples.
+
+## Demo 2 - Protocol Buffers file refactoring.
+* `prefixize.py`
+* Main use-case is rename refactoring of entities in Protocol Buffers.
+* [Protocol Buffers Objetive C compiler] [5] does not prefix entities and this may conflict with some objects in the project.
+This script renames all entties in protobuf file by prefixing them wth specified string. Also identifiers with conflicting
+names can be renamed if specified by parameter (e.g., hash, description). Result of this refactoring can be then used with
+objeciveC protoc without conflicts.
+
 ## Acknowledgement
 This work was inspired by:
 * [plyj] [2], Java lexer & parser for PLY.
 * [pyparsing] [3], Protocol Buffers parsing example. 
 * [PLYTalk] [4], nice tutorial for PLY I used.
- 
+
 ## Disclaimer
 * This project was created because I needed it for myself and I didn't find Protocol Buffers parser for PLY. 
 It is my first PLY / parser generator project and the first version was created in couple hours so it is not polished code. 
@@ -39,4 +56,5 @@ inspiration or a starting point. You will probably adapt it for your own needs.
  [1]: https://github.com/dabeaz/ply
  [2]: https://github.com/musiKk/plyj
  [3]: http://pyparsing.wikispaces.com/
- [4]: http://www.dabeaz.com/ply/PLYTalk.pdf
+ [4]: http://www.dabeaz.com/ply/PLYTalk.pdf
+ [5]: https://github.com/alexeyxo/protobuf-objc