[Haskell-cafe] Re: Why does the class called "Real" support only rationals, and not all reals?

Dan Piponi dpiponi at gmail.com
Mon Jun 4 13:54:04 EDT 2007

On 6/4/07, DavidA <polyomino at f2s.com> wrote:
> Yes, I'm afraid that you are understanding correctly. Annoying isn't it.
> It is well-known (among Haskell mathematicians at least) that the numeric type
> classes in the prelude are broken.

A few days ago I found myself forced to write:

> instance Floating Fixed where ...

where 'Fixed' is a fixed point arithmetic class! :-)

When you find yourself having to make a type an instance of the
complete 'opposite' class you know you have serious problems!

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