Proposal: Add conspicuously missing Functor instances for tuples

Ryan Scott at
Mon Jan 18 21:29:41 UTC 2016

I can sympathize with your sentiment. Normally, if there's a datatype
whose instance I don't want to use, I just make my own replacement.
However, it's hard to do that with tuples given their special
syntactic treatment.

It might be worth looking into adding RebindableSyntax for tuples [1]
to address scenarios like this.

Ryan S.

On Mon, Jan 18, 2016 at 4:22 PM, Henning Thielemann
<lemming at> wrote:
> On Mon, 18 Jan 2016, John Wiegley wrote:
>>>>>>> Henning Thielemann <lemming at> writes:
>>> I would never use such an instance. Can I be warned if I accidentally use
>>> it
>>> anyway?
>> I don't know why "I wouldn't use it" should extend to "it shouldn't
>> exist".
> Because I cannot turn it off and I cannot get warning. It is inserted by GHC
> whenever it matches, even if I made a mistake when programming.

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