def _parse_type(self):
"""
constructor: ConstructorId fields?
sum: constructor ('|' constructor)*
type: product | sum
"""
if self.cur_token.kind == TokenKind.LParen:
# If we see a (, it's a product
return self._parse_product()
else:
# Otherwise it's a sum. Look for ConstructorId
sumlist = []
while True:
cons_name = self._match(TokenKind.ConstructorId)
shared_type = None
fields = None
if self.cur_token.kind == TokenKind.LParen:
fields = self._parse_fields()
elif self.cur_token.kind == TokenKind.Percent:
self._advance()
shared_type = self._match(TokenKind.TypeId)
else:
pass
cons = Constructor(cons_name, shared_type, fields)
sumlist.append(cons)
if self.cur_token.kind != TokenKind.Pipe:
break
self._advance()
return Sum(sumlist, self._parse_optional_attributes())
def _parse_type(self):
if self.cur_token.kind == TokenKind.LParen:
# If we see a (, it's a product
return self._parse_product()
else:
# Otherwise it's a sum. Look for ConstructorId
sumlist = [Constructor(self._match(TokenKind.ConstructorId),
self._parse_optional_fields())]
while self.cur_token.kind == TokenKind.Pipe:
# More constructors
self._advance()
sumlist.append(Constructor(
self._match(TokenKind.ConstructorId),
self._parse_optional_fields()))
return Sum(sumlist, self._parse_optional_attributes())