[Haskell-cafe] Re: (flawed?) benchmark : sort

Neil Mitchell ndmitchell at gmail.com
Mon Mar 10 15:12:55 EDT 2008


>  "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



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