[swift-evolution] ternary operator ?: suggestion

[Paul Ossenbruggen]

that is cool thanks!

> On Dec 16, 2015, at 11:09 PM, Brent Royal-Gordon via swift-evolution <swift-evolution at swift.org> wrote:
> 
>> My reason for suggesting the change is that it would be nice to have a one liner for non-boolean values. Especially when the mapping isn't likely to be reused anyplace else. I run into this a fair amount, and the inline way I do it (via a Dict) requires a lot of verbosity (keys are likely to be Enums and need to be explicitly declared for the Dict).
> 
> You can improve the ergonomics of this with a custom operator:
> 
> 	infix operator ??? {}		// Used because ? is reserved; in practice, you should use something else.
> 	
> 	func ???<Key, Value>(key: Key, dictionary: [Key: Value]) -> Value {
> 	    return dictionary[key]!
> 	}
> 	
> 	let alignment = NSTextAlignment.Left
> 	alignment ??? [.Left: "Left", .Right: "Right", .Center: "Center", .Justified: "Justified"]
> 
> Actually, this *almost* does what you want. No @autoclosure for the values and no exhaustiveness checking, but otherwise...
> 
> -- 
> Brent Royal-Gordon
> Architechies
> 
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