More Higher-Kinded Typeclass Instances

Andrew Martin andrew.thaddeus at
Mon Mar 28 18:08:12 UTC 2016

Earlier today, I wrote Proxy's instances for Eq1, Ord1, Show1, and Read1
and they were accepted for base- All in all, the process went way
more smoothly than I expected, and so I started thinking about what other
types from base are currently missing these instances, and this is what
I've come up with:

    - Down (from Data.Ord)
    - Complex (from Data.Complex)
    - Ratio (from Data.Ratio)
    - First, Last (from Data.Monoid)
    - ZipList (from Control.Applicative)
    - Ptr, FunPtr (from Foreign.Ptr, only Eq1 and Ord1)
    - StablePtr (from Foreign.StablePtr, only Eq1)
    - K1, U1, Par1, Rec1, etc. (from GHC.Generics)
    - StableName (from System.Mem.StableName, only Eq1, requested here:

Since most of these are trivial to implement, I'd like to try to get them
in for GHC-8.0. Does anyone have in mind any other data types that would
benefit from these?

-Andrew Thaddeus Martin
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