Proposal: New Eq and Ord instances for Double and Float

Edward Kmett ekmett at
Mon Sep 26 07:23:05 CEST 2011

I too am against this proposal. 

I'd be for it for consistency if perhaps we were writing a language from scratch, because it has the transitive effect that one can't use pointer equality to short circuit structural equality checks anywhere the types involved are parametric or contain Floats, but it would subtly and silently break a good deal of existing code.


Sent from my iPad

On Sep 26, 2011, at 1:05 AM, "Bryan O'Sullivan" <bos at> wrote:

> On Sun, Sep 25, 2011 at 10:53 PM, Daniel Fischer < at> wrote:
> Proposal: Provide Double and Float with Eq and Ord instances that introduce
> a total order.
> I am strongly against this proposal, as it is in an area that is particularly poorly understood by most programmers (even experts). While the current behaviour may be undesirable from some points of view, at least it is consistent with most other programming languages - and this is one of the few areas where I think that's important.
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