constraint_hole_fits.hs:4:5: warning: [-Wtyped-holes (in -Wdefault)]
    • Found hole: _ :: [a] -> a
      Where: ‘a’ is a rigid type variable bound by
               the type signature for:
                 g :: forall a. Ord a => [a] -> a
               at constraint_hole_fits.hs:3:1-22
    • In an equation for ‘g’: g = _
    • Relevant bindings include
        g :: [a] -> a (bound at constraint_hole_fits.hs:4:1)
      Constraints include Ord a (from constraint_hole_fits.hs:3:1-22)
      Valid hole fits include
        g :: [a] -> a
        head :: forall a. [a] -> a
        last :: forall a. [a] -> a
        maximum :: forall (t :: * -> *) a. (Foldable t, Ord a) => t a -> a
        minimum :: forall (t :: * -> *) a. (Foldable t, Ord a) => t a -> a
      Valid refinement hole fits include
        foldl1 (_ :: a -> a -> a)
          where foldl1 :: forall (t :: * -> *) a.
                          Foldable t =>
                          (a -> a -> a) -> t a -> a
        foldr1 (_ :: a -> a -> a)
          where foldr1 :: forall (t :: * -> *) a.
                          Foldable t =>
                          (a -> a -> a) -> t a -> a
        foldl (_ :: a -> a -> a) (_ :: a)
          where foldl :: forall (t :: * -> *) b a.
                         Foldable t =>
                         (b -> a -> b) -> b -> t a -> b
        foldr (_ :: a -> a -> a) (_ :: a)
          where foldr :: forall (t :: * -> *) a b.
                         Foldable t =>
                         (a -> b -> b) -> b -> t a -> b
        const (_ :: a)
          where const :: forall a b. a -> b -> a
        ($) (_ :: [a] -> a)
          where ($) :: forall a b. (a -> b) -> a -> b
        return (_ :: a)
          where return :: forall (m :: * -> *) a. Monad m => a -> m a
        pure (_ :: a)
          where pure :: forall (f :: * -> *) a. Applicative f => a -> f a
        ($!) (_ :: [a] -> a)
          where ($!) :: forall a b. (a -> b) -> a -> b
        id (_ :: [a] -> a)
          where id :: forall a. a -> a
        head (_ :: [[a] -> a])
          where head :: forall a. [a] -> a
        last (_ :: [[a] -> a])
          where last :: forall a. [a] -> a
        asTypeOf (_ :: [a] -> a) (_ :: [a] -> a)
          where asTypeOf :: forall a. a -> a -> a
        (!!) (_ :: [[a] -> a]) (_ :: Int)
          where (!!) :: forall a. [a] -> Int -> a