def parse(starting_rule, text):
# text_with_indexes = enumerate([ None ] + text.lower().split())
import string
splitted = string.replace(text.lower(), ",", " , ").split()
text_with_indexes = enumerate([None] + splitted)
table = [Column(i, token) for i, token in text_with_indexes]
gamma_prod = ConstrainedProduction(constraint.new_empty_avm(), starting_rule)
table[0].add(ConstrainedState(GAMMA_RULE, gamma_prod, 0, gamma_prod.avm, table[0]))
for i, column in enumerate(table):
for state in column:
if state.is_completed():
complete(column, state)
else:
term = state.get_next_term()
if isinstance(term, Rule):
predict(column, term)
elif i + 1 < len(table):
scan(table[i + 1], state, term)
# XXX(sandello): You can uncomment this line to see full dump of
# the chart table.
#
# column.dump(only_completed = False)
# Find Gamma rule in the last table column or fail otherwise.
for state in table[-1]:
if state.name == GAMMA_RULE and state.is_completed():
return [tree for tree in build_trees(state, table)]
else:
return []
def process_rule(self, in_number, in_line):
line = in_line
n = in_number
parts = line.strip().split()
for part in parts:
if part != part.upper() and part != part.lower():
raise RuntimeError, "Malformed line #{0}: Mixed-case for term '{1}'".format(n + 1, part)
if len(parts) == 0:
return
if len(parts) == 1:
if parts[0] not in self.non_terminals:
raise RuntimeError, "Malformed line #{0}: Unknown non-terminal '{1}'".format(n + 1, parts[0])
else:
self.starting_rule = parts[0]
return
if parts[1] != "->":
raise RuntimeError, "Malformed line #{0}: Second part have to be '->'".format(n + 1)
lhs = self.get_term(parts[0])
rhs = map(self.get_term, parts[2:])
if not isinstance(lhs, Rule):
raise RuntimeError, "Malformed line #{0}: Left-hand side have to be a non-terminal".format(n + 1)
rhs_prod = ConstrainedProduction(constraint.new_empty_avm(), *rhs)
lhs.add(rhs_prod)
self.last_production = rhs_prod