Haskell: Data type containing other Data Types

Question

if I have two data structures

data Tri = Tri {a :: Int, b :: Int , c :: Int} deriving Show
data Quad = Quad {w :: Int, x :: Int, y :: Int, z :: Int} deriving Sh         


        

Answer 1

@talex's answer is correct. Here are some variations (mainly just different syntax).

Without record syntax:

data Shape = ShapeTri Tri | ShapeQuad Quad 
  deriving Show

It may make more sense to combine Shape, Tri, and Quad:

data Shape = Tri  {a :: Int, b :: Int , c :: Int} 
           | Quad {w :: Int, x :: Int, y :: Int, z :: Int}
  deriving Show

Answer 2

You have to give names to data constructors:

data Shape = ShapeTri  { shapeTri  :: Tri }
           | ShapeQuad { shapeQuad :: Quad } 
                 deriving Show