[swift-evolution] [Pitch] Eliminate tuples - unify member access syntax

[David Sweeris]

On Jan 8, 2017, at 09:33, Freak Show <freakshow42 at mac.com> wrote:

>> On Jan 7, 2017, at 22:51, David Sweeris <davesweeris at mac.com> wrote:
> 
>> A really convenient way to pass around multiple values without having to bother with a formal struct.
> 
> That's actually a big part of my concern.
> 
> The people on this list are, I'm certain, among the top programmers working.
> 
> I'm more worried about what happens when average (which IME means barely competent) developers get going with this.  I suspect nobody will ever declare a struct again.

Doubtful, since tuples can't have any computed properties, functions, or conform to protocols.

> Type declarations are valuable - they are an opportunity to express intent.  OTOH, a pair of ints is a pair of ints and if all pairs of ints are type compatible then opportunities for catching errors drop if developers start favoring anonymous tuples over former structs.

I don't think they are... "(Int, Int)" (without labels) will type-check to any pair of Ints, but IIRC "(x:Int, y:Int)" won't type-check to "(a:Int, b:Int)".

>> On Jan 7, 2017, at 23:37, Derrick Ho <wh1pch81n at gmail.com> wrote:
>> 
>> I think pattern matching is the most compelling reason to keep tuples.  
>> 
>> If they were gone, how would we replace the following?
>> 
>> switch (a, b) {
>> case (value1, value2):
>> case (value3, value4):
>> }
> 
> 
> I really have to ask.  What do you use this for?  In general iPhone application programming I have never wanted or needed to do that.  I do some AudioUnits as well.  Still never needed it.

"Need" is a strong word... Yeah, I could switch over the first value and then for every single case nest another switch over the second value, but that'd be annoying and obscure the underlying logic.

- Dave Sweeris
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