[was ghc-devs] Reasoning backwards with type families

[Clinton Mead]

Happy to go with the bogusness if it works better than injective types,
feel free to submit a patch. :)

On Thu, 14 Dec 2017 at 9:08 pm, Anthony Clayden <
anthony_clayden at clear.net.nz> wrote:

> On Thu, 14 Dec 2017 at 4:13 PM, Clinton Mead <redirect at vodafone.co.nz>
> wrote:
>
>>
>> I've panicked GHC enough whilst developing Freelude so whilst I'm not
>> sure exactly what you're saying I'd be hestiant about exploiting anything
>> bogus (8.2 btw seems far more stable than 8.0 btw).
>>
>
> ;-) Fair enough.
>
> "bogus" is SPJ's way of saying: it works, but it isn't supported by deep
> type theory. 'C'est brutal mais ca marche.'
>
> And that particular exploit has been stable since 2004 at least: the HList
> library totally relied on it until Closed Type Families arrived.
>
> AntC
>
>
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