[Haskell-cafe] A Generic Ordering over Types

[Justin Paston-Cooper]

Looks like cmptype wins on genericity. Out of interest, is there any
alternative these days to writing the tuple instances of CmpType
explicitly?

On Sat, 28 Dec 2019 at 23:29, Michael Sloan <mgsloan at gmail.com> wrote:
>
> Cool approach!
>
> cmptype does something similar, but requires a ghc plugin: https://github.com/isovector/type-sets/tree/master/cmptype
>
> I suppose one advantage of cmptype is that it can work with types that cannot derive Generic, such as GADTs.
>
> -Michael
>
> On Sat, Dec 28, 2019 at 3:23 AM Justin Paston-Cooper <paston.cooper at gmail.com> wrote:
>>
>> Hello,
>>
>> I've defined a module which defines a Data.Type.Ordering over types
>> which are instances of Generic:
>> https://github.com/jpcooper/generic-type-ordering/blob/master/src/Data/Type/Ordering.hs.
>> I was considering submitting it to Hackage if anyone finds this
>> useful.
>>
>> I am using it in conjunction with Data.Type.Set (type-level-sets),
>> which requires an ordering over the used types.
>>
>> The ordering works by first comparing the package, then the module,
>> then the type name. I take it that the ordering as defined is correct
>> over all types which are an instance of Generic.
>>
>> I wanted to check first whether this is done anywhere else, or in a
>> different, better way. Can anyone advise?
>>
>> Cheers,
>>
>> Justin
>> _______________________________________________
>> Haskell-Cafe mailing list
>> To (un)subscribe, modify options or view archives go to:
>> http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe
>> Only members subscribed via the mailman list are allowed to post.