[Haskell-cafe] Comments on Haskell 2010 Report

John Meacham john at repetae.net
Fri Jul 9 19:21:05 EDT 2010

On Fri, Jul 09, 2010 at 06:07:04PM -0500, Alex Stangl wrote:
> I wasn't arguing that 0**0 *ought* to be undefined, but that it
> is a reasonable policy, since, as you point out, it's a matter
> of ongoing debate. What I don't understand is why for y /= 0,
> 0**y would be undefined. Maybe the discontinuity at zero is
> undesirable.

I would think it is a typo in the report. Every language out there seems
to think 0**0 is 1 and 0**y | y /= 0 is 0. I am not sure whether it is
mandated by the IEEE standard but a quick review doesn't say they should
be undefined (and the report mentions all the operations with undefined
results), if anything it should be left for
instances to decide based on the underlying algebra of the specific
type and the report shouldn't mention it.


John Meacham - ⑆repetae.net⑆john⑈ - http://notanumber.net/

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