data A = B

data A = B -- ^ Hello

data A = 
  B -- ^ Hello

data A
  = B -- ^ Hello

data A = B | C

data A = B | C | D

data A = B | C 
  | D

data A = B 
  | C 
  | D

data A = B 
  | C 
  | D
  deriving Show

data A = B 
  | C 
  | D
  deriving (Show, Eq)

data A = B Int
  deriving (Show, Eq)

data A = B Int | C String
  deriving (Show, Eq)