holes.hs:3:5: Warning:
    Found hole ‘_’ with type: t
    Where: ‘t’ is a rigid type variable bound by
               the inferred type of f :: t at holes.hs:3:1
    Relevant bindings include f :: t (bound at holes.hs:3:1)
    In the expression: _
    In an equation for ‘f’: f = _

holes.hs:6:7: Warning:
    Found hole ‘_’ with type: Char
    Relevant bindings include
      x :: Int (bound at holes.hs:6:3)
      g :: Int -> Char (bound at holes.hs:6:1)
    In the expression: _
    In an equation for ‘g’: g x = _

holes.hs:8:5: Warning:
    Found hole ‘_’ with type: [Char]
    Relevant bindings include h :: [Char] (bound at holes.hs:8:1)
    In the first argument of ‘(++)’, namely ‘_’
    In the expression: _ ++ "a"
    In an equation for ‘h’: h = _ ++ "a"

holes.hs:11:15: Warning:
    Found hole ‘_’ with type: b0
    Where: ‘b0’ is an ambiguous type variable
    Relevant bindings include
      y :: [a] (bound at holes.hs:11:3)
      z :: [a] -> [a] (bound at holes.hs:11:1)
    In the second argument of ‘const’, namely ‘_’
    In the expression: const y _
    In an equation for ‘z’: z y = const y _