[swift-evolution] Modernize Switch/Case Statements?

[Thorsten Seitz]

Yep, that’s what I meant.

-Thorsten 


> Am 31.01.2016 um 20:02 schrieb Radosław Pietruszewski <radexpl at gmail.com>:
> 
>> 
>> // this is how I have to do things now
>> 
>> let _ : UILabel = {
>>     view.addSubview($0)
>>     CenterViewInSuperview($0,
>>         horizontal: true, vertical: false)
>>     $0.text = "Toggle me"
>>     $0.font = UIFont.boldSystemFontOfSize(36)
>>     ConstrainViews("V:[view1]-30-[view2]",
>>         views: $0, mySwitch)
>>     return $0
>> }(UILabel())
>> 
>> // vs (this does not exist in the language)
>> 
>> do {
>>     view.addSubview($0)
>>     CenterViewInSuperview($0,
>>         horizontal: true, vertical: false)
>>     $0.text = "Toggle me"
>>     $0.font = UIFont.boldSystemFontOfSize(36)
>>     ConstrainViews("V:[view1]-30-[view2]",
>>         views: $0, mySwitch)
>> }(UILabel())
> 
> 
> That’s an interesting pattern. I don’t think I’ve seen that one before.
> 
> How about:
> 
> do {
>     let v = UILabel()
>     view.addSubview(v)
>     CenterViewInSuperview(v,
>         horizontal: true, vertical: false)
>     v.text = "Toggle me"
>     v.font = UIFont.boldSystemFontOfSize(36)
>     ConstrainViews("V:[view1]-30-[view2]",
>         views: v, mySwitch)
> }
> 
> 
> Is it too bad? I certainly like it better because you introduce `v` ($0) at the beginning of the block, not at the end.
> 
> And while one letter variable name is kinda gross in general, I don’t mind it in such context just like I don’t have a problem with $0 in simple closures. It’s a common practice in Ruby, for example, that doesn’t have $x to define “obvious” closure arguments as one letter variables, like so:
> 
>    articles = article_data.map { |a| Article.new(a) }
> 
> — Radek
> 
>> On 31 Jan 2016, at 18:27, Erica Sadun via swift-evolution <swift-evolution at swift.org <mailto:swift-evolution at swift.org>> wrote:
>> 
>> 
>>> On Jan 31, 2016, at 1:34 AM, Thorsten Seitz via swift-evolution <swift-evolution at swift.org <mailto:swift-evolution at swift.org>> wrote:
>>> 
>>> 
>>> 
>>>> Am 30.01.2016 um 10:39 schrieb Haravikk via swift-evolution <swift-evolution at swift.org <mailto:swift-evolution at swift.org>>:
>>>> 
>>>> Actually, one thing we don’t have in Swift is the ability to just put blocks (curly braces) wherever we like, which in some languages is a useful tool for variable scope when you know you only need something for a short time, but might want to re-use the name.
>>> 
>>> You can use a "do" block for that.
>>> 
>>> do { ... }
>>> 
>>> -Thorsten 
>> 
>> do blocks don't let you introduce parameters for short-lived items:
>> 
>> 
>> // this is how I have to do things now
>> 
>> let _ : UILabel = {
>>     view.addSubview($0)
>>     CenterViewInSuperview($0,
>>         horizontal: true, vertical: false)
>>     $0.text = "Toggle me"
>>     $0.font = UIFont.boldSystemFontOfSize(36)
>>     ConstrainViews("V:[view1]-30-[view2]",
>>         views: $0, mySwitch)
>>     return $0
>> }(UILabel())
>> 
>> // vs (this does not exist in the language)
>> 
>> do {
>>     view.addSubview($0)
>>     CenterViewInSuperview($0,
>>         horizontal: true, vertical: false)
>>     $0.text = "Toggle me"
>>     $0.font = UIFont.boldSystemFontOfSize(36)
>>     ConstrainViews("V:[view1]-30-[view2]",
>>         views: $0, mySwitch)
>> }(UILabel())
>> 
>> -- E
>> 
>> 
>> _______________________________________________
>> swift-evolution mailing list
>> swift-evolution at swift.org <mailto:swift-evolution at swift.org>
>> https://lists.swift.org/mailman/listinfo/swift-evolution
> 

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