changed ContextFreeGrammar to CFG, WeightedGrammar to PCFG, and Stati…

…sticalGrammar to ProbabilisticGrammar

nltk/app/chartparser_app.py

@@ -51,7 +51,7 @@
                               SteppingChartParser, TopDownInitRule, TopDownPredictRule,
                               TreeEdge)
 from nltk.tree import Tree
-from nltk.grammar import Nonterminal, ContextFreeGrammar
+from nltk.grammar import Nonterminal, CFG
 from nltk.util import in_idle
 from nltk.draw.util import (CanvasFrame, ColorizedList,
                             EntryDialog, MutableOptionMenu,
@@ -2038,7 +2038,7 @@ def load_grammar(self, *args):
                     grammar = pickle.load(infile)
             else:
                 with open(filename, 'r') as infile:
-                    grammar = ContextFreeGrammar.fromstring(infile.read())
+                    grammar = CFG.fromstring(infile.read())
             self.set_grammar(grammar)
         except Exception as e:
             tkinter.messagebox.showerror('Error Loading Grammar',
@@ -2230,7 +2230,7 @@ def top_down_strategy(self, *e):
         self.apply_strategy(self._TD_STRATEGY, TopDownPredictEdgeRule)
 
 def app():
-    grammar = ContextFreeGrammar.fromstring("""
+    grammar = CFG.fromstring("""
     # Grammatical productions.
         S -> NP VP
         VP -> VP PP | V NP | V

nltk/app/rdparser_app.py

@@ -867,8 +867,8 @@ def app():
     Create a recursive descent parser demo, using a simple grammar and
     text.
     """
-    from nltk.grammar import ContextFreeGrammar
-    grammar = ContextFreeGrammar.fromstring("""
+    from nltk.grammar import CFG
+    grammar = CFG.fromstring("""
     # Grammatical productions.
         S -> NP VP
         NP -> Det N PP | Det N

nltk/app/srparser_app.py

@@ -772,7 +772,7 @@ def app():
     text.
     """
 
-    from nltk.grammar import Nonterminal, Production, ContextFreeGrammar
+    from nltk.grammar import Nonterminal, Production, CFG
     nonterminals = 'S VP NP PP P N Name V Det'
     (S, VP, NP, PP, P, N, Name, V, Det) = [Nonterminal(s)
                                            for s in nonterminals.split()]
@@ -796,7 +796,7 @@ def app():
         Production(Det, ['my']),
         )
 
-    grammar = ContextFreeGrammar(S, productions)
+    grammar = CFG(S, productions)
 
     # tokenize the sentence
     sent = 'my dog saw a man in the park with a statue'.split()

nltk/data.py

@@ -803,10 +803,10 @@ def load(resource_url, format='auto', cache=True, verbose=False,
         if format == 'text':
             resource_val = string_data
         elif format == 'cfg':
-            resource_val = nltk.grammar.ContextFreeGrammar.fromstring(
+            resource_val = nltk.grammar.CFG.fromstring(
                 string_data, encoding=encoding)
         elif format == 'pcfg':
-            resource_val = nltk.grammar.WeightedGrammar.fromstring(
+            resource_val = nltk.grammar.PCFG.fromstring(
                 string_data, encoding=encoding)
         elif format == 'fcfg':
             resource_val = nltk.grammar.FeatureGrammar.fromstring(

nltk/draw/cfg.py

@@ -54,7 +54,7 @@
 from tkinter import (Button, Canvas, Entry, Frame, IntVar, Label,
                      Scrollbar, Text, Tk, Toplevel)
 
-from nltk.grammar import (ContextFreeGrammar, _read_cfg_production,
+from nltk.grammar import (CFG, _read_cfg_production,
                           Nonterminal, nonterminals)
 from nltk.tree import Tree
 from nltk.draw.tree import TreeSegmentWidget, tree_to_treesegment
@@ -157,7 +157,7 @@ class CFGEditor(object):
     def __init__(self, parent, cfg=None, set_cfg_callback=None):
         self._parent = parent
         if cfg is not None: self._cfg = cfg
-        else: self._cfg = ContextFreeGrammar(Nonterminal('S'), [])
+        else: self._cfg = CFG(Nonterminal('S'), [])
         self._set_cfg_callback = set_cfg_callback
 
         self._highlight_matching_nonterminals = 1
@@ -482,7 +482,7 @@ def _ok(self, *e):
     def _apply(self, *e):
         productions = self._parse_productions()
         start = Nonterminal(self._start.get())
-        cfg = ContextFreeGrammar(start, productions)
+        cfg = CFG(start, productions)
         if self._set_cfg_callback is not None:
             self._set_cfg_callback(cfg)
 
@@ -666,7 +666,7 @@ def mainloop(self, *args, **kwargs):
         self._top.mainloop(*args, **kwargs)
 
 def demo2():
-    from nltk import Nonterminal, Production, ContextFreeGrammar
+    from nltk import Nonterminal, Production, CFG
     nonterminals = 'S VP NP PP P N Name V Det'
     (S, VP, NP, PP, P, N, Name, V, Det) = [Nonterminal(s)
                                            for s in nonterminals.split()]
@@ -691,7 +691,7 @@ def demo2():
         Production(N, ['dog']),  Production(N, ['statue']),
         Production(Det, ['my']),
         )
-    grammar = ContextFreeGrammar(S, productions)
+    grammar = CFG(S, productions)
 
     text = 'I saw a man in the park'.split()
     d=CFGDemo(grammar, text)
@@ -702,12 +702,12 @@ def demo2():
 ######################################################################
 
 def demo():
-    from nltk import Nonterminal, ContextFreeGrammar
+    from nltk import Nonterminal, CFG
     nonterminals = 'S VP NP PP P N Name V Det'
     (S, VP, NP, PP, P, N, Name, V, Det) = [Nonterminal(s)
                                            for s in nonterminals.split()]
 
-    grammar = ContextFreeGrammar.fromstring("""
+    grammar = CFG.fromstring("""
     S -> NP VP
     PP -> P NP
     NP -> Det N