universe.hs

{-# LANGUAGE DeriveDataTypeable #-}
{-# LANGUAGE DeriveGeneric #-}

import qualified Data.HashMap.Strict as HashMap
import Data.Data
import Data.HashMap.Strict (HashMap)
import qualified Data.Vector as Vector
import Data.Vector (Vector)
import Data.Generics.Uniplate.Data
import GHC.Generics

data Expr =
    LitInt Int
  | LitBool Bool
  | Struct (HashMap String Expr)
  | Array (Vector Expr)
  deriving (Eq, Show, Data, Typeable, Generic)

main :: IO ()
main = do
  print $ universe (Struct (HashMap.fromList [("one", LitInt 1), ("false", LitBool False)]))
  -- Prints: [Struct (fromList [("one",LitInt 1),("false",LitBool False)]),LitInt 1,LitBool False]
  print $ universe (Array (Vector.fromList [LitInt 1, LitBool False]))
  -- Prints: [Array (fromList [LitInt 1,LitBool False])]
  -- Expected: [Array (fromList [LitInt 1,LitBool False]), LitInt 1,LitBool False]