# -*- coding: utf-8 -*-
from __future__ import absolute_import, unicode_literals
import unittest

from nltk import RegexpParser

class TestChunkRule(unittest.TestCase):

    def test_tag_pattern2re_pattern_quantifier(self):
        """Test for bug https://github.com/nltk/nltk/issues/1597
    
        Ensures that curly bracket quantifiers can be used inside a chunk rule.
        This type of quantifier has been used for the supplementary example
        in http://www.nltk.org/book/ch07.html#exploring-text-corpora.
        """    
        sent = [('The', 'AT'), ('September-October', 'NP'), ('term', 'NN'), ('jury', 'NN'), ('had', 'HVD'), ('been', 'BEN'), ('charged', 'VBN'), ('by', 'IN'), ('Fulton', 'NP-TL'), ('Superior', 'JJ-TL'), ('Court', 'NN-TL'), ('Judge', 'NN-TL'), ('Durwood', 'NP'), ('Pye', 'NP'), ('to', 'TO'), ('investigate', 'VB'), ('reports', 'NNS'), ('of', 'IN'), ('possible', 'JJ'), ('``', '``'), ('irregularities', 'NNS'), ("''", "''"), ('in', 'IN'), ('the', 'AT'), ('hard-fought', 'JJ'), ('primary', 'NN'), ('which', 'WDT'), ('was', 'BEDZ'), ('won', 'VBN'), ('by', 'IN'), ('Mayor-nominate', 'NN-TL'), ('Ivan', 'NP'), ('Allen', 'NP'), ('Jr.', 'NP'), ('.', '.')] # source: brown corpus
        cp = RegexpParser('CHUNK: {<N.*>{4,}}')
        tree = cp.parse(sent)
        assert tree.pformat() == """(S
  The/AT
  September-October/NP
  term/NN
  jury/NN
  had/HVD
  been/BEN
  charged/VBN
  by/IN
  Fulton/NP-TL
  Superior/JJ-TL
  (CHUNK Court/NN-TL Judge/NN-TL Durwood/NP Pye/NP)
  to/TO
  investigate/VB
  reports/NNS
  of/IN
  possible/JJ
  ``/``
  irregularities/NNS
  ''/''
  in/IN
  the/AT
  hard-fought/JJ
  primary/NN
  which/WDT
  was/BEDZ
  won/VBN
  by/IN
  (CHUNK Mayor-nominate/NN-TL Ivan/NP Allen/NP Jr./NP)
  ./.)"""


Fix 1597. Allow for curly bracket quantifiers in nltk.chunk.regexp.CHUNK_TAG_PATTERN.
Fix 1597. Allow for curly bracket quantifiers in nltk.chunk.regexp.CHUNK_TAG_PATTERN.
