> Given all this, I think it makes sense to go for syntactic uniformity between
> parameter list and function types, and just require parenthesis on the
> argument list. The types above can be trivially written as:
>
> (Int) -> Float
> (String) -> ()
>
> Thoughts?
While it's technically correct, I agree with John's assessment that this is
"fussy". `T -> U` doesn't confuse people and doesn't confuse the compiler;
removing it would require extra punctuation for no particular reason. It would
also become inconsistent with the paren-less `{ param in … }` syntax, which I
think is very important for keeping usage sites simple and clean.
What I think we *should* eliminate, however, is using `Void` to mean "no
arguments" in a closure type. `Void -> Int` should mean that the type takes one
argument which happens to be an empty tuple. If you want no arguments, write
`() -> Int`. Similarly, a typedef for a 2-tuple (like `Dictionary.Element`)
should be recognized as one tuple parameter, not two singleton parameters. With
that in place, `T -> U` becomes merely a convenient shorthand for the canonical
form, `(T) -> U`.
I mean, it's not that big a deal; if you remove it, everyone will type extra
parentheses and live with it. But recognize that doing so would improve the
language, not the end-user experience.
--
Brent Royal-Gordon
Architechies
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