[Haskell-cafe] [Newbie] Cannot derive Eq and Show. Why?
bulat.ziganshin at gmail.com
Sat Sep 9 04:09:37 EDT 2006
Friday, September 8, 2006, 6:03:36 PM, you wrote:
> I am stumped again. The following code generates the error "ERROR
> file:.\Cube.hs:12 - An instance of IArray UArray a is required to derive Eq
> (Cube a b)" in Hugs. But I did specify the IArray UArray k constraint. So
> what is wrong?
> data (Ord k, IArray UArray k, IArray UArray v) =>
shortly speaking, you should either use boxed Array or switch to using
my ArrayRef library which supports polymorphic unboxed arrays
look for detailed explanations of problem to
ArrayRef library can be found at http://haskell.org/haskellwiki/Library/ArrayRef
for use with Hugs it need to be preprocessed via one of included
i have added your module to the library as the shortest example of using
polymorphic unboxed arrays :) see attached file. of course, if you
want that this file will be removed or modified, i will do
Bulat mailto:Bulat.Ziganshin at gmail.com
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