[swift-evolution] Change `repeat` to loop indefinitely if no while clause is present

[David Sweeris]

As am I. I like that the while clause can be optional, but I don't see the point of banning "while true".

- Dave Sweeris

> On May 10, 2016, at 14:10, Xiaodi Wu via swift-evolution <swift-evolution at swift.org> wrote:
> 
> Nicholas wrote that he would like `while true` to be a compile-time error. I'm curious as to why.
> 
> On Tue, May 10, 2016 at 13:47 Tyler Cloutier <cloutiertyler at aol.com> wrote:
>>> On May 10, 2016, at 12:39 AM, Xiaodi Wu via swift-evolution <swift-evolution at swift.org> wrote:
>>> 
>>>> On Tue, May 10, 2016 at 2:27 AM, Nicholas Maccharoli via swift-evolution <swift-evolution at swift.org> wrote:
>>>> ​Swift Evolution ​Community,
>>>> 
>>>> Currently writing an infinite loop in swift looks either something like this:
>>>> 
>>>>     while true {
>>>>         if ... { break }
>>>>         //...
>>>>     }
>>>> 
>>>> Or this:
>>>> 
>>>>     repeat {
>>>>         if ... { break }
>>>>         //...
>>>>     } while true
>>>> 
>>>> But I think it might be best to change the syntax / behaviour of `repeat` to loop 
>>>> indefinitely if no trailing while clause is present:
>>>> 
>>>>     repeat {
>>>>         if ... { break }
>>>>         //...
>>>>     }
>>>> 
>>>> while still allowing a trailing `while` clause as in:
>>>> 
>>>>     repeat { 
>>>>         foo += bar
>>>>     } while foo.count < limit 
>>>  
>>> What is your motivation for this change?
>>>  
>>>> I also want to propose that it should be a compile time error to use single `Bool` constants as while loop conditions, so no more `while true { ... }` it would become `repeat { ... }`
>>> 
>>> What problems are solved by forbidding `while true`?
>> 
>> I don’t think the proposal is forbidding it, but rather making it optional. So that 
>> 
>> repeat {
>> 
>> } 
>> 
>> is equivalent to 
>> 
>> repeat {
>> 
>> } while true
>> 
>>>  
>>>> I was thinking of drafting a short proposal if there was enough positive feedback. 
>>>> 
>>>> How does it sound?
>>>> 
>>>> - Nick 
>>>> 
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>>> 
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