CharToNat and NatToChar type families
@RyanGlScott’s work on singletons
revealed that built-in type families added in 7f3524ef are insufficient to implement a promoted variant of Show Char
.
For Show
, we need CharToNat
. And with NatToChar
to accompany it, we can also define promoted Enum Char
.
These type families were originally part of !3598, but it is currently on hold because it’s unclear whether we want to add so many built-in definitions (and also because the author currently has no time to rebase it and clean it up, at least in time for the %9.2.1 release). However, now there’s a clear case for CharToNat
and NatToChar
, so this ticket is to track their addition.
Patch here: !5258 (closed)