Proposal (long term): Remove (/=) from Eq; change the semantics of (==) for floating point

Kim-Ee Yeoh ky3 at
Thu Sep 25 04:09:14 UTC 2014

On Thu, Sep 25, 2014 at 10:25 AM, David Feuer <david.feuer at> wrote:

> As Edward Kmett explained to me, (/=) is currently needed in Eq to support
> IEEE floating point semantics for (==) and (/=). As I see it, those
> semantics are badly broken from the perspective of what Eq is supposed to
> mean, and really should be supported using special functions (eqIEEE and
> neqIEEE or whatever), whereas the most appropriate Eq instance for floating
> point would be something more like

A short-term improvement you could make is to move this discussion to
haskell-cafe. By reaching a larger audience with lots more stakeholders,
you'll garner support and assistance putting your proposal in the best
light possible.

-- Kim-Ee
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