def la_not_in_set(self, lookahead_exclusions):
if all(len(excl) == 1 for excl in lookahead_exclusions):
return grammar.LookaheadRule(
OrderedFrozenSet(excl[0] for excl in lookahead_exclusions),
False)
raise ValueError("unsupported: lookahead > 1 token, {!r}".format(
lookahead_exclusions))
def la_not_in_set(self, notin, ob, lookahead_exclusions, cb):
assert (notin, ob, cb) == ("<!", '{', '}')
if all(len(excl) == 1 for excl in lookahead_exclusions):
return grammar.LookaheadRule(
OrderedFrozenSet(excl[0] for excl in lookahead_exclusions),
False)
raise ValueError("unsupported: lookahead > 1 token, {!r}".format(
lookahead_exclusions))
def la_not_in_nonterminal(self, nt):
return grammar.LookaheadRule(OrderedFrozenSet([nt]), False)
def la_ne(self, t):
return grammar.LookaheadRule(OrderedFrozenSet([t]), False)
def la_eq(self, t):
return grammar.LookaheadRule(OrderedFrozenSet([t]), True)
def la_ne(self, ne, t):
assert ne == "!="
return grammar.LookaheadRule(OrderedFrozenSet([t]), False)
def la_eq(self, eq, t):
assert eq == "=="
return grammar.LookaheadRule(OrderedFrozenSet([t]), True)
