[swift-evolution] What about a VBA style with Statement?

[Taras Zakharko]

We had this kind of proposal earlier, didn’t seem to be very well received. I still think it would be a useful thing, but I’d do it as a statement (extension of do) that introduces new lexical  scope (similar to self)

— Taras

> On 13 Apr 2016, at 16:25, Sean Heber via swift-evolution <swift-evolution at swift.org> wrote:
> 
> This pair works pretty well, too, if you don’t mind free functions:
> 
> func with<T>(inout this: T, @noescape using: inout T->Void) { using(&this) }
> func with<T>(this: T, @noescape using: T->Void) { using(this) }
> 
> It works either with classes or mutable structs if you call it correctly and the type doesn’t matter.
> 
> l8r
> Sean
> 
> 
>> On Apr 13, 2016, at 9:17 AM, Radosław Pietruszewski via swift-evolution <swift-evolution at swift.org> wrote:
>> 
>> It can be (more-or-less) solved in library code today:
>> 
>> extension NSObjectProtocol {
>>    public func with(@noescape fn: Self -> Void) -> Self {
>>        fn(self)
>>        return self
>>    }
>> }
>> 
>> This way, you can do, on NSObjects:
>> 
>> textLabel.with {
>> 	$0.textAlignment = .Left
>> 	$0.textColor = .darkTextColor()
>> }
>> 
>> I love this pattern.
>> 
>> You can also make it a function to make it work with any value of any kind (it will then take form of `with(foo) { …}`).
>> 
>> Ideally, if you could write a universal extension (something like `extension Any`), you could just add this behavior, with method syntax, to everything.
>> 
>> — Radek
>> 
>>> On 13 Apr 2016, at 15:15, 李海珍 via swift-evolution <swift-evolution at swift.org> wrote:
>>> 
>>> I recently learned some VBA and I found a very conveniently `with` statement.
>>> 
>>> `with` statement can be helpful to set property for UIKit instance.
>>> 
>>> for instance a UILabel instance `textLabel` ,with `with` statement we can set UILabel property like this
>>> 
>>> 
>>> 
>>> ```swift
>>> 
>>> with textLabel{
>>> 
>>> .textAlignment = .Left
>>> 
>>> .textColor = UIColor.darkTextColor()
>>> 
>>> .font = UIFont.systemFontOfSize(15)
>>> 
>>> }
>>> 
>>> ```
>>> 
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