[Haskell-cafe] No Derived Read for Unboxed Arrays

Donald Bruce Stewart dons at cse.unsw.edu.au
Thu Jan 25 19:12:03 EST 2007


ndmitchell:
> Hi,
> 
> >I was trying to convert some code from ordinary boxed array to unboxed
> >arrays for performance reasons.
> 
> >However my code ultimately failed because
> >I load a large array saved as a text file using the derived Read, Show
> >mechanism.
> 
> I found that Read was maybe 30 times slower than the slowest binary
> serialisation method I could possibly think of. If performance matters
> to you, and the array is more than a few elements long, switching away
> from Read/Show should be the first step - before going for unboxed
> arrays.
> 
> (But of course, having Read/Show defined for UArray may well be
> useful, and sounds a good idea)

There's also an instance Binary for UArray. That might be useful?

-- Don


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