> On 18 Apr 2017, at 15:29, Matt Lewin via swift-evolution
> <[email protected]> wrote:
>
> In contrast, the proposed solution of
> // half-open right-handed range
> let greeting = s[..<i]
> // closed right-handed range
> let withComma = s[...i]
> // left-handed range (no need for half-open variant)
> let location = s[i...]
> requires both the code-writer and the code-reader to infer the missing side
> is the start or end.
>
> From my perspective, this obfuscates the language by reducing the ability of
> the code to be read as English. (One of the goals of Swift design, correct?)
I mentioned in an earlier reply that my preference would be to retain use of
the binary operator and use Void as the open end like so:
func ... <T:Comparable>(lhs:T, rhs:Void) -> PartialRangeFrom<T> { … }
func ... <T:Comparable>(lhs:Void, rhs:T) -> PartialRangeTo<T> { … }
let rangeFrom = 5...()
let rangeTo = ()...5
Would that solve your concern? Ideally we could also push for underscore to
become another alias for Void when used in such a context, so we could do:
let rangeFrom = 5..._
let rangeTo = _...5
This to me is a bit more explicit that one end of the range being left open on
purpose. I initially considered some kind of other symbol, but I think
Void/underscore is suitable enough, underscore especially as it's consistent
with other features._______________________________________________
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