Add StoryboardSegue

[tomlokhorst]

Starting work on mac-cain13/R.swift#158

With this, a segue (identifier & source) can be wrapped up in a new value, e.g.:

let segueFromSecondToThird = R.segue.secondViewController.toThird.storyboardSegueWithSource(self)

And it can later on be performed:

segueFromSecondToThird.performSegue()

[tomlokhorst]

I've removed the UIViewController extension performSegueWithIdentifier and replaced it with one that only works on segues with the correct source view controller type.

For example:

// This wil compile
let master = MasterViewController()
master.performSegueWithIdentifier(R.segue.masterViewController.goToDetail)

// This won't compile, because the `Source` types don't match
let detail = DetailViewController()
detail.performSegueWithIdentifier(R.segue.masterViewController.goToDetail)

[mac-cain13]

I don't really like the name of this protocol and the empty extension below. Could we change it to just an extension of UIViewController?

[tomlokhorst]

No, it can't be an extension on UIViewController, because of the Self requirement:

'Self' is only available in a protocol or as the result of a method in a class; did you mean 'UIViewController'?

So that's why a protocol is needed. I'm unsure if there is some fundamental type system reason for this. Or simply a limitation of the current Swift compiler implementation. If its a "bug" in the compiler, we can assume it will be fixed at some point in the future, and then we can remove this protocol.

And yeah, I don't really like the name either. I thought of it because of things like CollectionType and SequenceType. ¯_(ツ)/¯

[mac-cain13]

Fair point. We should only think about a better name in that case.

[tomlokhorst]

Alternatives:

• PerformSegueWithIdentifierable
• PerformSegueable
• Segueable
• UIViewControllerPerformSegue
• ViewControllerSegueable

I don't really like any of these, but I'm slightly leaning to the last ViewControllerSegueable.

[mac-cain13]

Merged. I renamed the protocol to SeguePerformerType