TypeClassTest.purs

module TypeClassTest where

import Prelude
import Unsafe.Coerce (unsafeCoerce)

class TwoParams a b where
  func :: a -> b

instance equals :: TwoParams a a where
  func = identity
else
instance any :: TwoParams a b where
  func = unsafeCoerce

-- test2 :: forall a. a -> Array a
-- test2 = func
test3 :: forall m a. a -> m a
test3 = func
--      ^^^^
--
--   No type class instance was found for
--
--     TypeClassTest.TwoParams a0
--                             (m1 a0)
--
--
-- while checking that type forall b a. TwoParams a b => a -> b
--   is at least as general as type a0 -> m1 a0
-- while checking that expression func
--   has type a0 -> m1 a0
-- in value declaration test3
--
-- where a0 is a rigid type variable
--         bound at (line 18, column 9 - line 18, column 13)
--       m1 is a rigid type variable
--         bound at (line 18, column 9 - line 18, column 13)
--