Did you mean the thread "Mutability inference"? What I talked about is different from it. I am against the idea of "Mutability inference".
What I talked about is just enabling to omit `let` for constant declarations. It distinguishes the following three explicitly. > - assignment > - declaration of a constant > - declaration of a mutable variable `:=` makes it possible to distinguish assignments and constant declarations. -- Yuta 2016-04-01 23:55 GMT+09:00 Radosław Pietruszewski <[email protected]>: > I can’t easily find it, but there’s been at least one thread proposing this > exact thing, and there was very little interest in the proposal. > > TL;DR is that Swift *by design* wants to make the difference between these > three concepts: > > - assignment > - declaration of a constant > - declaration of a mutable variable > > as explicit and obvious as possible. > > — Radek > >> On 01 Apr 2016, at 13:58, Yuta Koshizawa via swift-evolution >> <[email protected]> wrote: >> >> I think it would be good if the following three declarations were equivalent >> >> let a: Int = 42 >> a: Int = 42 >> a := 42 >> >> and also the following two were. >> >> let a: Int >> a: Int >> >> Then constant declarations become shorter than variable declarations. >> It encourages people to use constants in preference to variables. >> >> It also prevents repeating `let` for property declarations and makes >> type declarations simpler. >> >> struct Person { >> firstName: String >> lastName: String >> age: Int >> } >> >> Omitting `let` is consistent with that we don't write `let` for >> arguments of functions and iterated values in for-in loops. >> >> Not `=` but `:=` for type inferences because `=` cannot distinguish >> whether it means a constant declaration or an assignment to a variable >> declared in an outer scope. I think `:=` is a natural notation for >> type inferences because omitting the type from `a: Int = 42` makes >> `a:= 42`. Because I have not strictly checked if it can be parsed in >> Swift properly, it may have some other parsing issues. >> >> What do you think about it? >> >> -- Yuta >> _______________________________________________ >> 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
