shithub: MicroHs

ref: 581fb546cf42e1d63f56ac724aeb8b871de8251e
dir: /tests/Coerce.hs/

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module Coerce where
import Data.Coerce

newtype NT = NT Int
  deriving (Show)

newtype List a = List [a]
  deriving (Show)

toInt :: (Coercible a Int) => a -> Int
toInt = coerce

toInts :: (Coercible a Int) => [a] -> [Int]
toInts = coerce

main :: IO ()
main = do
  print (toInt (NT 5))
  print (toInts [NT 1, NT 2] :: [Int])
  print (coerce (List [3::Int, 4]) :: [Int])
  print (coerce (List [NT 5, NT 6]) :: [NT])
  print (coerce (List [NT 7, NT 8]) :: [Int])