[Haskell-cafe] Re: (flawed?) benchmark : sort
Neil Mitchell
ndmitchell at gmail.com
Mon Mar 10 15:12:55 EDT 2008
Hi
> "The Ord class is used for totally ordered datatypes."
>
> This *requires* that it be absolutely impossible in valid code to
> distinguish equivalent (in the EQ sense, not the == sense) things via
> the functions of Ord. The intended interpretation of these functions is
> clear and can be taken as normative:
>
> forall f . (compare x y == EQ and (f x or f y is defined))
> ==> f x == f y)
Are you sure? I would have read this as the ordering must be
reflexive, antisymetric and transitive - the standard restrictions on
any ordering. See http://en.wikipedia.org/wiki/Total_ordering
Thanks
Neil
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