def demo():
from nltk import Nonterminal, ContextFreeGrammar
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("""
S -> NP VP
PP -> P NP
NP -> Det N
NP -> NP PP
VP -> V NP
VP -> VP PP
Det -> 'a'
Det -> 'the'
Det -> 'my'
NP -> 'I'
N -> 'dog'
N -> 'man'
N -> 'park'
N -> 'statue'
V -> 'saw'
P -> 'in'
P -> 'up'
P -> 'over'
P -> 'with'
""")
def cb(grammar): print(grammar)
top = Tk()
editor = CFGEditor(top, grammar, cb)
Label(top, text='\nTesting CFG Editor\n').pack()
Button(top, text='Quit', command=top.destroy).pack()
top.mainloop()
def demo(N=23):
from nltk.grammar import ContextFreeGrammar
print('Generating the first %d sentences for demo grammar:' % (N, ))
print(demo_grammar)
grammar = ContextFreeGrammar.fromstring(demo_grammar)
for n, sent in enumerate(generate(grammar, n=N), 1):
print('%3d. %s' % (n, ' '.join(sent)))
def app():
"""
Create a recursive descent parser demo, using a simple grammar and
text.
"""
from nltk.grammar import ContextFreeGrammar
grammar = ContextFreeGrammar.fromstring("""
# Grammatical productions.
S -> NP VP
NP -> Det N PP | Det N
VP -> V NP PP | V NP | V
PP -> P NP
# Lexical productions.
NP -> 'I'
Det -> 'the' | 'a'
N -> 'man' | 'park' | 'dog' | 'telescope'
V -> 'ate' | 'saw'
P -> 'in' | 'under' | 'with'
""")
sent = 'the dog saw a man in the park'.split()
RecursiveDescentApp(grammar, sent).mainloop()
def demo():
from nltk import Nonterminal, ContextFreeGrammar
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("""
S -> NP VP
PP -> P NP
NP -> Det N
NP -> NP PP
VP -> V NP
VP -> VP PP
Det -> 'a'
Det -> 'the'
Det -> 'my'
NP -> 'I'
N -> 'dog'
N -> 'man'
N -> 'park'
N -> 'statue'
V -> 'saw'
P -> 'in'
P -> 'up'
P -> 'over'
P -> 'with'
""")
def cb(grammar):
print(grammar)
top = Tk()
editor = CFGEditor(top, grammar, cb)
Label(top, text='\nTesting CFG Editor\n').pack()
Button(top, text='Quit', command=top.destroy).pack()
top.mainloop()
