Ceylon uses `Nothing` for the bottom type. -Thorsten
> Am 05.06.2016 um 20:39 schrieb Charlie Monroe via swift-evolution > <[email protected]>: > > While None is probably the best way to describe the opposite of Any, it would > be often mistaken for .None (i.e. Optional) by newcomers to the language. > > I'd personally prefer calling it "Nil" (capital N), which really means > "nonexistent". The same way ObjC had "nil" for "id" and "Nil" for Class. > Possibly, to avoid confusion with nil, calling it Null? Though that might get > confused with NSNull, once the NS prefix gets dropped. > > Or "Nothing" as in Scala. > >> On Jun 5, 2016, at 8:26 PM, Антон Жилин via swift-evolution >> <[email protected]> wrote: >> >> The following names were suggested: NoReturn, Bottom, None, Never. >> I would pick None, because it looks like opposite to Any and fits nicely in >> generic types. >> >> I would prefer the type to be simple, and be implemented as a case-less enum >> (not a bottom value, as in Haskell). >> >> None should be a usual enum, with no compiler magic except that functions >> returning None are equivalent to current @noreturn. >> >> Example 1. >> let x: None? >> // ... >> let y = x! >> >> It will trap in runtime not because we discover scary bottom thing, as in >> Haskell, but because x had value Optional.none at that moment and we >> asserted otherwise. >> We could prove that it is always true in this case, but compiler must be >> stupid about this. >> >> Example 2. >> Compiler should allow including None in structures. Error will show up in >> constructor, when we will not be able to initialize the field. >> >> Example 3. >> None in an enum case makes that case never appear in values of such a type. >> But compiler can not know about that. >> >> - Anton >> _______________________________________________ >> swift-evolution mailing list >> [email protected] >> https://lists.swift.org/mailman/listinfo/swift-evolution > > _______________________________________________ > swift-evolution mailing list > [email protected] > https://lists.swift.org/mailman/listinfo/swift-evolution _______________________________________________ swift-evolution mailing list [email protected] https://lists.swift.org/mailman/listinfo/swift-evolution
