nltk/nltk — pull request #278 by nschneid (2012-06-18 21:24:06+00:00)
Title: Support symlinking to a full installation of the Penn Treebank via the ptb module (and companion modules propbank_ptb and nombank_ptb).

Note that this change:

* Allows for retrieval of corpora symlinked from the `nltk_data` directory
* Introduces the class `CategorizedBracketParseCorpusReader`, which is used for the Penn Treebank to allow selection of categories such as `news` (WSJ) or `fiction`, `humor`, `romance`, etc. (Brown).