constant :: Parser Literal
constant = choice
  [ Identifier <$> identifier
  , IntegerLit <$> integerLit
  , FloatLit <$> floatLit
  , StringLit <$> stringLit
  , BoolLit <$> boolLit ]
constant :: Parser Literal
constant = choice
  [ Identifier <$> identifier
  , IntegerLit <$> integerLit
  , FloatLit <$> floatLit
  , StringLit <$> stringLit
  , BoolLit <$> boolLit ]
constant = choice
  [ Identifier <$> identifier
  , IntegerLit <$> integerLit
  , FloatLit <$> floatLit
  , StringLit <$> stringLit
  , BoolLit <$> boolLit ]