T10045.hs:6:18: error:
    • Found type wildcard ‘_’ standing for ‘t2 -> Bool -> t1’
      Where: ‘t2’ is a rigid type variable bound by
               the inferred type of copy :: t2 -> Bool -> t1 at T10045.hs:7:10-34
             ‘t1’ is a rigid type variable bound by
               the inferred type of copy :: t2 -> Bool -> t1 at T10045.hs:7:10-34
      To use the inferred type, enable PartialTypeSignatures
    • In the type signature: copy :: _
      In the expression:
        let
          copy :: _
          copy w from = copy w True
        in copy ws1 False
      In an equation for ‘foo’:
          foo (Meta ws1)
            = let
                copy :: _
                copy w from = copy w True
              in copy ws1 False
    • Relevant bindings include
        ws1 :: () (bound at T10045.hs:5:11)
        foo :: Meta -> t (bound at T10045.hs:5:1)