fork download
copy 
  1. {-# LANGUAGE ExistentialQuantification #-}
  2.  
  3. data Value = A Int
  4.  
  5. data ForallFunc = forall a. Eq a => Forall (Value -> a) 
  6.  
  7. unpackA (A int) = int
  8.  
  9. equalityTest :: Value -> Value -> ForallFunc -> Bool            
  10. equalityTest arg1 arg2 (Forall unpacker) =
  11.   let a1 = unpacker arg1
  12.       a2 = unpacker arg2 in
  13.     a1 == a2
  14.  
  15. main = putStrLn $ show $ equalityTest (A 1) (A 1) (Forall unpackA)
Success #stdin #stdout 0s 4548KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
True
https://ideone.com/lJCFQy
language:
Haskell (ghc 8.4.4)
created:
6 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!