[swift-evolution] [Pitch] Retiring `where` from for-in loops

[Charlie Monroe]

> On Jun 13, 2016, at 4:46 PM, Xiaodi Wu <xiaodi.wu at gmail.com> wrote:
> 
> On Mon, Jun 13, 2016 at 9:28 AM, Sean Heber <sean at fifthace.com <mailto:sean at fifthace.com>> wrote:
> I’m just (probably obtusely) suggesting that there are different levels and styles of expression and that the existence of one does not render other styles invalid.
> 
> In relation to the “where” debate, the fact that you can express everything with “guard” or “if” as you can with “where” is not, in my mind, a strong  argument against “where” because it ignores other more intangible aspects that are going to be a lot harder to quantify since they depend on the context of the problem, the surrounding code, the mindset of the writer, and the assumed mindset of the reader.
> 
> I don’t dispute that we *could* live without “where” - that is not the point. We could also live without classes or generics or any of a variety of other features - but why should we when we don’t have to?
> 
> I'm not sure where this comes in. I was clarifying what I mean when I call a language construct 'expressive.' As I understand the term, `where` is not expressive, whereas classes and generics are expressive.

Perhaps this is due to English not being my first language, but I go by the dictionary definition of expressive:

expressive (adjective) - effectively conveying thought or feeling.

And I believe that for-in-where is expressing the condition more effectively (and efficiently) than adding if/guard-continue into the actual code block.

>  
> 
> l8r
> Sean
> 
> 
> > On Jun 13, 2016, at 9:19 AM, Xiaodi Wu <xiaodi.wu at gmail.com <mailto:xiaodi.wu at gmail.com>> wrote:
> >
> > How do you mean? I don't follow.
> > On Mon, Jun 13, 2016 at 09:11 Sean Heber <sean at fifthace.com <mailto:sean at fifthace.com>> wrote:
> > > On Jun 13, 2016, at 9:05 AM, Xiaodi Wu via swift-evolution <swift-evolution at swift.org <mailto:swift-evolution at swift.org>> wrote:
> > >
> > > On Mon, Jun 13, 2016 at 8:58 AM, Charlie Monroe <charlie at charliemonroe.net <mailto:charlie at charliemonroe.net>> wrote:
> > > if-continue. But I gladly took upon for-in-where as soon as I found out about it since it's more expressive and simply is less typing.
> > >
> > > I don't think we use the term 'expressive' in the same way. I understand it to mean that permitting the expression of more things. But of course, `where` does only a subset of `guard...continue` or `if...continue`; thus, less expressive.
> >
> > The fact that you could simply use the words “I am happy” to express the concept of being happy does not mean that writing a complex poem that also conveys happiness should therefore be prohibited.
> >
> > l8r
> > Sean
> >
> 
> 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.swift.org/pipermail/swift-evolution/attachments/20160613/400ae41c/attachment.html>