Any enum type has an instance for equality. Remember that enums are declared so a type checked declared enum is a well-typed enum that can only have the underlying types of bit<w>, int<w>, or typedef and all of these types have equality instances. Thus, there is no need to check if the underlying type has such an instance. However, at the moment, Petr4 checks this which is unnecessary.
Petr4 code
type_has_equality_tests env (typ: Typed.Type.t) =
match reduce_type env typ with
...
| Enum { typ; _ } ->
begin match typ with
| Some typ -> type_has_equality_tests env typ
| None -> true
end
...
Any enum type has an instance for equality. Remember that enums are declared so a type checked declared enum is a well-typed enum that can only have the underlying types of
bit<w>,int<w>, ortypedefand all of these types have equality instances. Thus, there is no need to check if the underlying type has such an instance. However, at the moment, Petr4 checks this which is unnecessary.Petr4 code
Fix: just drop the condition.