def parse(self, tokens):
self._grammar.check_coverage(tokens)
chart = Chart(list(tokens))
grammar = self._grammar
# Chart parser rules.
bu_init = ProbabilisticBottomUpInitRule()
bu = ProbabilisticBottomUpPredictRule()
fr = SingleEdgeProbabilisticFundamentalRule()
# Our queue
queue = []
# Initialize the chart.
for edge in bu_init.apply(chart, grammar):
if self._trace > 1:
print(
' %-50s [%s]'
% (chart.pretty_format_edge(edge, width=2), edge.prob())
)
queue.append(edge)
while len(queue) > 0:
# Re-sort the queue.
self.sort_queue(queue, chart)
# Prune the queue to the correct size if a beam was defined
if self.beam_size:
self._prune(queue, chart)
# Get the best edge.
edge = queue.pop()
if self._trace > 0:
print(
' %-50s [%s]'
% (chart.pretty_format_edge(edge, width=2), edge.prob())
)
# Apply BU & FR to it.
queue.extend(bu.apply(chart, grammar, edge))
queue.extend(fr.apply(chart, grammar, edge))
# Get a list of complete parses.
parses = list(chart.parses(grammar.start(), ProbabilisticTree))
# Assign probabilities to the trees.
prod_probs = {}
for prod in grammar.productions():
prod_probs[prod.lhs(), prod.rhs()] = prod.prob()
for parse in parses:
self._setprob(parse, prod_probs)
# Sort by probability
parses.sort(reverse=True, key=lambda tree: tree.prob())
return iter(parses)
def parse(self, tokens):
self._grammar.check_coverage(tokens)
chart = Chart(list(tokens))
grammar = self._grammar
# Chart parser rules.
bu_init = ProbabilisticBottomUpInitRule()
bu = ProbabilisticBottomUpPredictRule()
fr = SingleEdgeProbabilisticFundamentalRule()
# Our queue
queue = []
# Initialize the chart.
for edge in bu_init.apply(chart, grammar):
if self._trace > 1:
print(' %-50s [%s]' %
(chart.pretty_format_edge(edge, width=2), edge.prob()))
queue.append(edge)
while len(queue) > 0:
# Re-sort the queue.
self.sort_queue(queue, chart)
# Prune the queue to the correct size if a beam was defined
if self.beam_size:
self._prune(queue, chart)
# Get the best edge.
edge = queue.pop()
if self._trace > 0:
print(' %-50s [%s]' %
(chart.pretty_format_edge(edge, width=2), edge.prob()))
# Apply BU & FR to it.
queue.extend(bu.apply(chart, grammar, edge))
queue.extend(fr.apply(chart, grammar, edge))
# Get a list of complete parses.
parses = list(chart.parses(grammar.start(), ProbabilisticTree))
# Assign probabilities to the trees.
prod_probs = {}
for prod in grammar.productions():
prod_probs[prod.lhs(), prod.rhs()] = prod.prob()
for parse in parses:
self._setprob(parse, prod_probs)
# Sort by probability
parses.sort(reverse=True, key=lambda tree: tree.prob())
return iter(parses)
def nbest_parse(self, tokens, n=None):
# now the tokens comes from continuse set
chart = Chart(list(tokens))
grammar = self._grammar
bu_init = ProbabilisticBottomUpInitRule()
bu = ProbabilisticBottomUpPredictRule()
fr = SingleEdgeProbabilisticFundamentalRule()
em = ProbabilisticEmissionRule()
queue = []
for edge in bu_init.apply_iter(chart, grammar):
if self._trace > 1:
print(' %-50s [%s]' % (chart.pp_edge(edge,width=2),
edge.prob()))
queue.append(edge)
while len(queue) > 0:
self.sort_queue(queue, chart)
if self.beam_size:
self._prune(queue, chart)
edge = queue.pop()
if self._trace > 0:
print(' %-50s [%s]' % (chart.pp_edge(edge,width=2),
edge.prob()))
queue.extend(em.apply(chart, grammar, edge))
queue.extend(bu.apply(chart, grammar, edge))
queue.extend(fr.apply(chart, grammar, edge))
parses = chart.parses(grammar.start(), ProbabilisticTree)
prod_probs = {}
for prod in grammar.productions():
prod_probs[prod.lhs(), prod.rhs()] = prod.prob()
for parse in parses:
self._setprob(parse, prod_probs, grammar.density())
parses.sort(reverse=True, key=lambda tree: tree.prob())
return parses[:n]
def __init__(self, tokens):
Chart.__init__(self, tokens)
def __init__(self, tokens):
Chart.__init__(self, tokens)
def parse(self, tokens, notify=True, max=0):
'''Run a probabilistic parse of tokens.
If notify is true, display each complete parse as it is found
If max>0, quit after finding that many parses'''
self._grammar.check_coverage(tokens)
chart = Chart(list(tokens))
chart._trace = self._trace # Bad form. . .
grammar = self._grammar
start = grammar.start()
prod_probs = {}
# Chart parser rules.
bu_init = ProbabilisticBottomUpInitRule()
bu = BetterPBPR() # avoid infinite numbers of parses :-(
fr = BetterSEPFR() # don't look at pending edges
# Our queue
queue = []
# Initialize the chart.
for edge in bu_init.apply(chart, grammar):
if self._trace > 1:
print(' %-50s [%.4g]' % (chart.pretty_format_edge(
edge, width=2), cost(edge.prob())))
queue.append(edge)
found = 0
while len(queue) > 0 and (max < 1 or found < max):
# Re-sort the queue.
self.sort_queue(queue, chart)
# Prune the queue to the correct size if a beam was defined
if self.beam_size:
self._prune(queue, chart)
# Get the best edge.
edge = queue.pop()
edge.pending = False
if self._trace > 0:
print(' %-50s [%.4g]' % (chart.pretty_format_edge(
edge, width=2), cost(edge.prob())))
if (edge.start() == 0 and edge.end() == chart._num_leaves
and edge.lhs() == start and edge.is_complete()):
if len(prod_probs) == 0:
for prod in grammar.productions():
prod_probs[prod.lhs(), prod.rhs()] = prod.prob()
if notify:
print("****")
for tree in chart.trees(edge,
tree_class=ProbabilisticTree,
complete=True):
self._setprob(tree, prod_probs)
print('{}{:.4g}({:.4g})'.format(
tree, cost(tree.prob()), cost(edge.prob())))
#print tree
print("****")
found += 1
# Apply BU & FR to it.
queue.extend(fr.apply(chart, grammar, edge))
queue.extend(bu.apply(chart, grammar, edge))
# Get a list of complete parses.
parses = list(chart.parses(grammar.start(), ProbabilisticTree))
if not notify:
for parse in parses:
self._setprob(parse, prod_probs)
# Sort by probability
parses.sort(key=lambda tree: tree[0], reverse=True)
if notify:
print("{0} total parses found".format(found))
return iter(parses)
