[swift-evolution] [Proposal] Improving operator requirements in protocols

[Tony Allevato]

I like this suggestion a lot. Using labels has a nice elegance to it and
makes the usage very clear. If we drop the -ing like Chris suggests, it
also aligns nicely with the same keywords used to define them.

I'm not a parser expert, but this seems like it might be easier to parse
than fully-qualified operators. It is visually, at least.

On Mon, May 2, 2016 at 4:59 PM Xiaodi Wu via swift-evolution <
swift-evolution at swift.org> wrote:

> Hmm, a thought going in a slightly different direction: if these static
> functions were called like any other function, there might not be a need
> for having special rules for parameter labels, which can then be freed to
> denote prefix and postfix operators. In other words, we could have:
>
> * for infix operators, no labels, like so: `static func + (_ lhs: T, _
> rhs: T)`, used like this: `T.+(1, 2)`
> * for prefix and postfix operators, a label, like so: `static func +
> (prefixing value: T)`, used like this: `T.+(prefixing: 1)`
>
>
> On Mon, May 2, 2016 at 6:26 PM, David Sweeris via swift-evolution <
> swift-evolution at swift.org> wrote:
>
>>
>> On May 2, 2016, at 5:58 PM, Chris Lattner via swift-evolution <
>> swift-evolution at swift.org> wrote:
>>
>> On May 2, 2016, at 1:56 PM, Dave Abrahams via swift-evolution <
>> swift-evolution at swift.org> wrote:
>>
>>   How does one distinguish between calls to a static prefix operator and a
>>   static postfix operator with the same name?
>>
>> Ah, that's a tricky one that I don't have an immediate answer to, so I'm
>> definitely open to creative thoughts here.
>>
>>
>> One possibility: just use “qualified operator” notation.
>>
>>   lhs T.+= rhs
>>
>>   T.++x
>>   x T.++
>>
>>
>> I’m not sure if this is exactly right, but it seems close.  I think that
>> something like this is probably the best way to go, since it composes
>> properly in arbitrary expressions.  It does have a surface level weirdness
>> to it, but it also "makes sense” in terms of how operators work.
>>
>> Yeah… Maybe with parens?
>>
>> T.++(x)
>> (x)T.++
>>
>> Or is that worse?
>>
>> - Dave Sweeris
>>
>> _______________________________________________
>> swift-evolution mailing list
>> swift-evolution at swift.org
>> https://lists.swift.org/mailman/listinfo/swift-evolution
>>
>>
> _______________________________________________
> swift-evolution mailing list
> swift-evolution at swift.org
> https://lists.swift.org/mailman/listinfo/swift-evolution
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.swift.org/pipermail/swift-evolution/attachments/20160503/f78d4572/attachment.html>