text: # coding: utf-8
  
  from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from __future__ import unicode_literals
  
  import codecs
  import os
  import re
  import sys
  from xml.dom import minidom
  
  from nltk.tree import Tree
  
  from .WordTokenizer import WordTokenizer
  
  
  def coarse_pos_e(tags):
      """
      Coarse POS tags of Treebank corpus: N: Noun, V: Verb, A: Adjective,
      D: Adverb, Z: Pronoun, T: Determiner, E: Preposition, P: Postposition,
      U: Number, J: Conjunction, O: Punctuation, R: Residual, L: Classifier,
      I: Interjection
  
      >>> coarse_pos_e(['Nasp---', 'pers', 'prop'])
      'N'
      """
  
      pos_map = {'N': 'N', 'V': 'V', 'A': 'AJ',
                 'D': 'ADV', 'Z': 'PRO', 'T': 'DET',
                 'E': 'P', 'P': 'POSTP', 'U': 'NUM',
                 'J': 'CONJ', 'O': 'PUNC', 'R': 'RES',
                 'L': 'CL', 'I': 'INT'}
      try:
          if tags[0][0] == 'C':
              if 'pronominal' in tags:
                  tags[0] = 'Z'
              elif 'verb' in tags:
                  tags[0] = 'V'
              elif 'prep' in tags:
                  tags[0] = 'E'
              elif 'adv' in tags:
                  tags[0] = 'D'
              elif 'det' in tags:
                  tags[0] = 'T'
          return pos_map[tags[0][0]] + ('e' if 'ezafe' in tags else '')
      except Exception:
          return ''
  
  
  class TreebankReader:
      """
      interfaces [Per­si­an Tree­bank](http://hpsg.fu-berlin.de/~ghayoomi/PTB.html)
  
      >>> treebank = TreebankReader(root='corpora/treebank')
      >>> print(next(treebank.trees()))
      (S
        (VPS
          (NPC (N دنیای/Ne) (MN (N آدولف/N) (N بورن/N)))
          (VPC
            (NPC (N دنیای/Ne) (NPA (N اتفاقات/Ne) (ADJ رویایی/AJ)))
            (V است/V)))
        (PUNC ./PUNC))
  
      >>> next(treebank.sents())
      [('دنیای', 'Ne'), ('آدولف', 'N'), ('بورن', 'N'), ('دنیای', 'Ne'),
      ('اتفاقات', 'Ne'), ('رویایی', 'AJ'), ('است', 'V'), ('.', 'PUNC')]
  
      >>> from .Chunker import tree2brackets
      >>> tree2brackets(next(treebank.chunked_trees()))
      '[دنیای آدولف بورن NP] [دنیای اتفاقات رویایی NP] [است VP] .'
      """
  
      def __init__(self, root, pos_map=coarse_pos_e, join_clitics=False,
                   join_verb_parts=False):
          self._root = root
          self._pos_map = pos_map if pos_map else lambda tags: ','.join(tags)
          self._join_clitics = join_clitics
          self._join_verb_parts = join_verb_parts
          self._tokenizer = WordTokenizer()
  
      def docs(self):
          for root, dirs, files in os.walk(self._root):
              for name in sorted(files):
                  try:
                      with codecs.open(os.path.join(root, name),
                                       encoding='utf8') as treebank_file:
                          raw = re.sub(r'\n *', '', treebank_file.read())
                          yield minidom.parseString(raw.encode('utf8'))
                  except Exception as e:
                      print('error in reading', name, e, file=sys.stderr)
  
      def trees(self):
  
          def traverse(node):
              def extract_tags(W):
                  pos = [W.getAttribute('lc') if W.getAttribute('lc') else None]
                  if W.getAttribute('clitic') in {'ezafe', 'pronominal', 'verb',
                                                  'prep', 'adv', 'det'}:
                      pos.append(W.getAttribute('clitic'))
                  if W.getAttribute('ne_sort'):
                      pos.append(W.getAttribute('ne_sort'))
                  if W.getAttribute('n_type'):
                      pos.append(W.getAttribute('n_type'))
                  if W.getAttribute('ya_type'):
                      pos.append(W.getAttribute('ya_type'))
                  if W.getAttribute('ke_type'):
                      pos.append(W.getAttribute('ke_type'))
                  if W.getAttribute('type'):
                      pos.append(W.getAttribute('type'))
                  if W.getAttribute('kind'):
                      pos.append(W.getAttribute('kind'))
                  return pos
  
              def clitic_join(tree, clitic):
                  if type(tree[-1]) == Tree:
                      return clitic_join(tree[-1], clitic)
                  else:
                      if clitic[0][0][0] == 'ا':
                          clitic[0] = ('‌' + clitic[0][0], clitic[0][1])
                      tree[-1] = (tree[-1][0] + clitic[0][0], clitic[0][1])
                      tree.set_label('CLITICS')
                      return
  
              if not len(node.childNodes):
                  return
              first = node.childNodes[0]
              if first.tagName == 'w':
                  pos = extract_tags(first)
                  return Tree(node.tagName, [(first.childNodes[0].data.replace(
                      'می ', 'می‌'), self._pos_map(pos))])
              childs = node.childNodes[
                       2:] if node.tagName == 'S' else node.childNodes
              for child in childs:
                  if not len(child.childNodes):
                      childs.remove(child)
              tree = Tree(node.tagName, map(traverse, childs))
              if self._join_clitics and len(tree) > 1 and type(
                      tree[1]) == Tree and tree[1].label() == 'CLITIC' and \
                      tree[1][0][1] not in {'P', 'V'}:
                  clitic = tree[-1]
                  tree = Tree(tree.label(), [subtree for subtree in tree[0]])
                  clitic_join(tree, clitic)
              if self._join_verb_parts and len(tree) > 1 and type(
                      tree[1]) == Tree and type(tree[0]) == Tree and tree[
                  0].label() == 'AUX' and tree[0][0][
                  0] in self._tokenizer.before_verbs:
                  tree[1][0] = (
                      tree[0][0][0] + ' ' + tree[1][0][0], tree[1][0][1])
                  tree.remove(tree[0])
              if self._join_verb_parts and len(tree.leaves()) > 1 and \
                      tree.leaves()[-1][
                          0] in self._tokenizer.after_verbs and \
                      tree.leaves()[-2][0] in self._tokenizer.verbe:
                  tree[1][0] = (
                      tree[0].leaves()[-1][0] + ' ' + tree[1][0][0],
                      tree[1][0][1])
                  path = tree.leaf_treeposition(len(tree.leaves()) - 2)
                  removingtree = tree
                  while len(path) > 2:
                      removingtree = removingtree[path[0]]
                      path = path[1:]
                  removingtree.remove(
                      Tree(tree.pos()[-2][1], [tree.pos()[-2][0]]))
              if self._join_verb_parts and len(tree.leaves()) > 1 and \
                      tree.leaves()[-1][
                          0] in self._tokenizer.after_verbs and \
                      tree.leaves()[-2][0] in self._tokenizer.verbe:
                  tree[1][0] = (
                      tree[0].leaves()[-1][0] + ' ' + tree[1][0][0],
                      tree[1][0][1])
                  path = tree.leaf_treeposition(len(tree.leaves()) - 2)
                  removingtree = tree
                  while len(path) > 2:
                      removingtree = removingtree[path[0]]
                      path = path[1:]
                  removingtree.remove(
                      Tree(tree.pos()[-2][1], [tree.pos()[-2][0]]))
              return tree
  
          for doc in self.docs():
              for S in doc.getElementsByTagName('S'):
                  yield traverse(S)
  
      def sents(self):
          for tree in self.trees():
              yield tree.leaves()
  
      def collapse(self, node, label):
          return Tree(label,
                      [Tree(pos[1], [pos[0]]) for pos in
                       node.pos()])
  
      def chunked_trees(self):
  
          def traverse(node, parent, chunks):
              label = node.label()
  
              if label.count('-nid') > 0:
                  label = label.replace('-nid', '')
              if label.count('-nid') > 0:
                  label = label.replace('-nid', '')
              if label.count('-DiscA') > 0:
                  label = label.replace('-DiscA', '')
  
              if label in {'CLITIC', 'CLITICS'}:
                  if node[0][1] == 'V':
                      label = 'V'
                  elif node[0][1] == 'P':
                      label = 'PREP'
                  elif node[0][1] == 'DET':
                      label = 'DET'
                  elif node[0][1] == 'ADV':
                      label = 'ADV'
                  elif node[0][1] == 'PRO':
                      label = 'PRON'
  
              if label in {'CONJ', 'PUNC'} and len(node) == 1:
                  chunks.append(node)
                  return
  
              if label == 'PPC' and len(node) == 1:
                  chunks.append(Tree('PP', [node[0]]))
                  return
  
              if label == 'PREP':
                  chunks.append(Tree('PP', [node]))
                  return
  
              if label == 'PostP':
                  chunks.append(Tree('POSTP', [node]))
                  return
  
              for leaf in node.pos():
                  if leaf[1] in {'PUNC', 'CONJ', 'PREP', 'PostP'}:
                      for i in range(len(node)):
                          traverse(node[i], node, chunks)
                      return
  
              if label == 'NPA' and parent.label() in {'CPC', 'PPC'}:
                  chunks.append(self.collapse(node, 'NP'))
                  return
  
              if label == 'NPA' and len(node) >= 1:
                  if node[0].label() == 'ADV':
                      chunks.append(self.collapse(node, 'NP'))
                      return
  
              if label in {'NPC', 'N', 'INFV', 'DPA', 'CLASS', 'DPC', 'DEM',
                           'INTJ', 'MN', 'PRON', 'DET', 'NUM', 'RES'}:
                  chunks.append(self.collapse(node, 'NP'))
                  return
  
              if label == 'NPA' and len(node) >= 2:
                  if node[0].label() == 'ADJ' and node[1].label() == 'NPC' or \
                          node[0].label() in {'N', 'PRON'} and node[
                      1].label() in {'ADJ', 'ADJPA', 'N'} or node[
                      0].label() == 'NUM' and node[1].label() in {'N', 'NPC',
                                                                  'MN',
                                                                  'NUM'} or \
                          node[0].label() in {'N', 'NPC', 'MN'} and node[
                      1].label() == 'NUM' or node[
                      0].label() == 'NPC' and node[1].label() == 'ADJ' or node[
                      0].label() == 'NPA' and node[
                      1].label() != 'NPC' or node[1].label() == 'NPA' and node[
                      0].label() != 'NPC':
                      chunks.append(self.collapse(node, 'NP'))
                      return
  
              if label == 'DPC' and len(node) >= 2:
                  chunkable = True
                  for leaf in node[1].pos():
                      if leaf[1] in {'PUNC', 'CONJ', 'PREP', 'PostP'}:
                          chunkable = False
                  if node[1].label() in {'N', 'NPA', 'NPC'} and chunkable:
                      chunks.append(self.collapse(node, 'NP'))
                      return
  
              if label == 'DPA' and len(node) >= 2:
                  if node[1].label() == 'ADV':
                      chunks.append(self.collapse(node, 'ADVP'))
                      return
  
              if label in {'MV', 'V', 'AUX', 'PPARV'}:
                  chunks.append(Tree('VP', [node]))
                  return
  
              if label in {'ADJ', 'ADJPC', 'MADJ', 'ADVPA'}:
                  chunks.append(Tree('ADJP', [node]))
                  return
  
              if label in {'ADV', 'MADV', 'ADVPC'}:
                  chunks.append(Tree('ADVP', [node]))
                  return
  
              if type(node[0]) != Tree:
                  chunks.append(node)
                  return
  
              for i in range(len(node)):
                  traverse(node[i], node, chunks)
  
          for tree in self.trees():
              chunks = []
              traverse(tree, None, chunks)
              for i in range(len(chunks)):
                  if chunks[i].label() in {'PUNC', 'CONJ'}:
                      chunks[i] = chunks[i][0]
                  else:
                      chunks[i] = Tree(chunks[i].label(), chunks[i].leaves())
              yield Tree('S', chunks)
  