What about a VBA style with Statement?

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@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@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@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


with textLabel{

.textAlignment = .Left

.textColor = UIColor.darkTextColor()

.font = UIFont.systemFontOfSize(15)

}

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