8.2.1: Ord TyCon is gone?

Ben Gamari ben at smart-cactus.org
Sat Jul 29 16:06:56 UTC 2017

Brandon Allbery <allbery.b at gmail.com> writes:

> On Sat, Jul 29, 2017 at 10:07 AM, Ben Gamari <ben at smart-cactus.org> wrote:
>> Hmm. I am unable to reproduce this,
>>     $ ghci
>>     λ> import Type.Reflection
>>     λ> let tc = typeRepTyCon (typeRep @Int)
>>     λ> tc == tc
>>     True
>> Does that work for you?
> Maybe I'm missing something, but doesn't that only test Eq, not Ord?
Oh dear, I somehow understood that you were referring to Typeable's
TyCon, not the ghc library's TyCon. Ignore my message.

Indeed the TyCon Ord instance is gone to help enforce determinism within
GHC. If you need a map use UniqFM.


- Ben
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