hole_constraints.hs:8:6: warning: [-Wtyped-holes (in -Wdefault)]
    • Found hole: _ :: a
      Where: ‘a’ is a rigid type variable bound by
               the type signature for:
                 f1 :: forall a. Eq a => a
               at hole_constraints.hs:7:1-15
    • In an equation for ‘f1’: f1 = _
    • Relevant bindings include
        f1 :: a (bound at hole_constraints.hs:8:1)
      Constraints include Eq a (from hole_constraints.hs:7:1-15)
      Valid hole fits include f1 :: a

hole_constraints.hs:12:6: warning: [-Wtyped-holes (in -Wdefault)]
    • Found hole: _ :: a
      Where: ‘a’ is a rigid type variable bound by
               the type signature for:
                 f2 :: forall a. (Show a, Eq a) => a
               at hole_constraints.hs:11:1-25
    • In an equation for ‘f2’: f2 = _
    • Relevant bindings include
        f2 :: a (bound at hole_constraints.hs:12:1)
      Constraints include
        Show a (from hole_constraints.hs:11:1-25)
        Eq a (from hole_constraints.hs:11:1-25)
      Valid hole fits include
        f2 :: a
        f1 :: forall a. Eq a => a

hole_constraints.hs:16:35: warning: [-Wtyped-holes (in -Wdefault)]
    • Found hole: _ :: [a]
      Where: ‘a’ is a rigid type variable bound by
               the instance declaration
               at hole_constraints.hs:16:10-22
    • In an equation for ‘f3’: f3 = _
      In the instance declaration for ‘C [a]’
    • Relevant bindings include
        f3 :: [a] (bound at hole_constraints.hs:16:30)
      Constraints include Eq a (from hole_constraints.hs:16:10-22)
      Valid hole fits include
        f3 :: [a]
        f1 :: forall a. Eq a => a
        [] :: forall a. [a]
        mempty :: forall a. Monoid a => a

hole_constraints.hs:20:19: warning: [-Wtyped-holes (in -Wdefault)]
    • Found hole: _ :: a
      Where: ‘a’ is a rigid type variable bound by
               the type signature for:
                 castWith :: forall a b. (a :~: b) -> a -> b
               at hole_constraints.hs:19:1-29
    • In an equation for ‘castWith’: castWith Refl x = _
    • Relevant bindings include
        x :: a (bound at hole_constraints.hs:20:15)
        castWith :: (a :~: b) -> a -> b (bound at hole_constraints.hs:20:1)
      Constraints include b ~ a (from hole_constraints.hs:20:10-13)
      Valid hole fits include x :: a

hole_constraints.hs:27:32: warning: [-Wtyped-holes (in -Wdefault)]
    • Found hole: _ :: String
    • In a case alternative: AnyShow x -> _
      In the expression: case a of AnyShow x -> _
      In an equation for ‘foo’: foo a = case a of AnyShow x -> _
    • Relevant bindings include
        x :: a (bound at hole_constraints.hs:27:27)
        a :: AnyShow (bound at hole_constraints.hs:27:5)
        foo :: AnyShow -> String (bound at hole_constraints.hs:27:1)
      Constraints include Show a (from hole_constraints.hs:27:19-27)
      Valid hole fits include
        f3 :: forall a. C a => a
        f1 :: forall a. Eq a => a
        f2 :: forall a. (Show a, Eq a) => a
        [] :: forall a. [a]
        mempty :: forall a. Monoid a => a