def __init__(self, ast=None, ctx=None):
super().__init__(ast=ast, ctx=ctx)
self._lookahead = None
self._firstset = None
self._follow_set = set()
self.value = None
self._nullability = self._nullable()
if isinstance(self._nullability, int): # Allow simple boolean values
if self._nullability:
self._nullability = Nullable.yes()
else:
self._nullability = Nullable.no()
def _nullable(self):
return Nullable.of(self.exp)
def _nullable(self):
return Nullable.any(self.options)
def _nullable(self):
return Nullable.all(self.sequence)