g.hs

copyByteStringToByteArray :: BS.ByteString -> ByteArray
copyByteStringToByteArray (BS.PS fp off len) =
    unsafeDupablePerformIO $
      withForeignPtr fp $ \ptr -> do
        mba <- newByteArray len
        copyPtrToMutableByteArray mba 0 (ptr `plusPtr` off) len
        unsafeFreezeByteArray mba

lib/Network/DNS/Pattern.hs:111:9: error:
    • Ambiguous type variable ‘a0’ arising from a use of ‘copyPtrToMutableByteArray’
      prevents the constraint ‘(Data.Primitive.Types.Prim
                                  a0)’ from being solved.
      Probable fix: use a type annotation to specify what ‘a0’ should be.
      These potential instances exist:
        instance Data.Primitive.Types.Prim Word8
          -- Defined in ‘Data.Primitive.Types’
        instance Data.Primitive.Types.Prim Char
          -- Defined in ‘Data.Primitive.Types’
        instance Data.Primitive.Types.Prim Double
          -- Defined in ‘Data.Primitive.Types’
        ...plus three others
        ...plus 70 instances involving out-of-scope types
        (use -fprint-potential-instances to see them all)
    • In a stmt of a 'do' block:
        copyPtrToMutableByteArray mba 0 (ptr `plusPtr` off) len
      In the expression:
        do mba <- newByteArray len
           copyPtrToMutableByteArray mba 0 (ptr `plusPtr` off) len
           unsafeFreezeByteArray mba
      In the second argument of ‘($)’, namely
        ‘\ ptr
           -> do mba <- newByteArray len
                 copyPtrToMutableByteArray mba 0 (ptr `plusPtr` off) len
                 ....’
    |
111 |         copyPtrToMutableByteArray mba 0 (ptr `plusPtr` off) len
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

gistfile2.txt

lib/Network/DNS/Pattern.hs:111:50: error:
    • Found type wildcard ‘_’ standing for ‘Ptr Word8’
      To use the inferred type, enable PartialTypeSignatures
    • In an expression type signature: _
      In the first argument of ‘plusPtr’, namely ‘(ptr :: _)’
      In the third argument of ‘copyPtrToMutableByteArray’, namely
        ‘((ptr :: _) `plusPtr` off)’
    • Relevant bindings include
        mba :: Data.Primitive.ByteArray.MutableByteArray
                 ghc-prim-0.7.0:GHC.Prim.RealWorld
          (bound at lib/Network/DNS/Pattern.hs:110:9)
        ptr :: Ptr Word8 (bound at lib/Network/DNS/Pattern.hs:109:28)
        len :: Int (bound at lib/Network/DNS/Pattern.hs:107:41)
        off :: Int (bound at lib/Network/DNS/Pattern.hs:107:37)
        fp :: GHC.ForeignPtr.ForeignPtr Word8
          (bound at lib/Network/DNS/Pattern.hs:107:34)
        copyByteStringToByteArray :: BS.ByteString -> ByteArray
          (bound at lib/Network/DNS/Pattern.hs:107:1)
    |
111 |         copyPtrToMutableByteArray mba 0 ((ptr :: _) `plusPtr` off) len
    |                                                  ^

gistfile3.txt

lib/Network/DNS/Pattern.hs:111:65: error:
    • Found type wildcard ‘_’ standing for ‘Ptr b’
      Where: ‘b’ is a rigid type variable bound by
               the inferred type of <expression> :: Ptr b
               at lib/Network/DNS/Pattern.hs:111:65
      To use the inferred type, enable PartialTypeSignatures
    • In an expression type signature: _
      In the third argument of ‘copyPtrToMutableByteArray’, namely
        ‘((ptr `plusPtr` off) :: _)’
      In a stmt of a 'do' block:
        copyPtrToMutableByteArray mba 0 ((ptr `plusPtr` off) :: _) len
    • Relevant bindings include
        mba :: Data.Primitive.ByteArray.MutableByteArray
                 ghc-prim-0.7.0:GHC.Prim.RealWorld
          (bound at lib/Network/DNS/Pattern.hs:110:9)
        ptr :: Ptr Word8 (bound at lib/Network/DNS/Pattern.hs:109:28)
        len :: Int (bound at lib/Network/DNS/Pattern.hs:107:41)
        off :: Int (bound at lib/Network/DNS/Pattern.hs:107:37)
        fp :: GHC.ForeignPtr.ForeignPtr Word8
          (bound at lib/Network/DNS/Pattern.hs:107:34)
        copyByteStringToByteArray :: BS.ByteString -> ByteArray
          (bound at lib/Network/DNS/Pattern.hs:107:1)
    |
111 |         copyPtrToMutableByteArray mba 0 ((ptr `plusPtr` off) :: _) len
    |