Re: [Haskell-cafe] A Generic Ordering over Types

I'm not sure why cmptype lists the tuple instances explicitly, since the plugin also handles tuple types. I can delete those cases and it still passes the tests. -Michael On Sun, Dec 29, 2019 at 12:51 AM Justin Paston-Cooper < paston.cooper@gmail.com> wrote:

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 wrote:

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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@gmail.com> wrote:

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...

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/... .

...

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.