What's the equiv. Swift Closure-Callback to Objective-C's block callback?

Question

I'm trying to translate the following Objective-C callback:

typedef void (^MKLocalSearchCompletionHandler)(MKLocalSearchResponse *response, NSError *error);

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...into its equivalent Swift callback:

typealias MKLocalSearchCompletionHandler = (MKLocalSearchResponse!, NSError!) -> Void

enter image description here

...obvious I lost my way here.
What would be the correct 'shell' or 'structure' of the Swift callback?

In general it's better practice to copy and paste your code instead of a screen shot of your code, the former is far more legible. — David Berry
– David Berry, Commented Oct 21, 2014 at 22:39

Bryan Chen · Accepted Answer · 2014-10-21 21:20:41Z

The syntax is incorrect. It should be

let handler : MKLocalSearchCompletionHandler = { (r: MKLocalSearchResponse?, e: NSError?) in /*do something*/ }

and better to omit the argument type and let compiler infer it

let handler : MKLocalSearchCompletionHandler = { r, e in /*do something*/ }

BTW, when you post question next time, use text instead of image. So I can copy & paste & modify your code and it is also searchable by others.

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