alt Hacker NewsI'm fairly sure he's referring to enumerations actually.
Pascal doesn't require case matching of enumerations to be exhaustive, but this can be turned on as a compiler warning in modern Pascal environments, FreePascal / Lazarus and such.
Go only has enums by convention, hence the "iota dance" referred to. I've argued before that this does qualify as "having enums" but just barely.
It wouldn't have been difficult to do a much better job of it, is the thing.
> Pascal doesn't require case matching of enumerations to be exhaustive
Normally in Pascal you would not match on the enumeration at all, but rather on the sum types.
The only reason for enumerations in Pascal (and other languages with similar constructs) is because under the hood the computer needs a binary representation to identify the type, and an incrementing number (an enum) is a convenient source for an identifier. In a theoretical world where the machine is magic you could have the sum types without enums, but in this reality...Thus, yes, in practice it is possible to go around the type system and get the enumerated value out with Ord(foo), but at that point its just an integer and your chance at exhaustive matching is out the window. It is the type system that allows more flexibility in what the compiler can tell you, not the values generated by the enumeration.
> Go only has enums by convention
"Enums by convention" would be manually typing 1, 2, 3, 4, etc. into the code. Indeed, that too is an enumeration, but not as provided by the language. Go actually has enums as a first-class feature of the language[1]. You even say so yourself later on, so this statement is rather curious. I expect you are confusing enums with sum types again.
[1] Arguably Pascal doesn't even have that, only using enums as an implementation detail to support its sum types. Granted, the difference is inconsequential in practice.