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.error { color:#AA0000; }</style></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div class="bloop_markdown"><pre><code class="swift">// I'll use this `function` as a closure later
func setup(_ this: SomeType) -> Void {
this.doSomeStuff() // local parameter `this`
}
setup(this: /* instance of SomeType */)
</code></pre>
<p>The example I’ll use here will build upon the code samples from the “Request for Discussion: Setup closures” topic.</p>
<pre><code class="swift">protocol SettableType: class {
init() // designated initializer
}
extension SettableType {
init(@noescape setup: (this: Self) -> Void) {
self.init()
setup(this: self)
}
}
func << <T: SettableType>(instance: T, @noescape setup: (this: T) -> Void) -> T {
setup(this: instance)
return instance
}
extension NSObject: SettableType {}
</code></pre>
<p>Right now this will look like this:</p>
<pre><code class="swift">NSObject() { anyArgumentName in
anyArgumentName.doSomeStuff()
}
// or
NSObject() {
$0.doSomeStuff()
}
</code></pre>
<p>If we had strict local parameter names we couold omit the argument list and don’t need the shorthand argument names ($0, $1) anymore. At least the argument list could be generated automaticaly.</p>
<p>Lets reuse the <code>SettableType</code> from before.</p>
<pre><code class="swift">extension SettableType {
init(@noescape setup: (_ this: Self) -> Void) {
// notice that `this` is now a local parameter and _ the external paramter
self.init()
setup(self) // in this scope only the external parameter is visible
}
}
func << <T: SettableType>(instance: T, @noescape setup: (_ this: T) -> Void) -> T {
setup(instance) // same here
return instance
}
let object = NSObject() { this in // we could omit the argument list
this.doSomeStuff() // `this` is the generated argument name from the strict local parameter
$0.doSomeStuff() // should raise an error even if we omit the argument list
}
object << {
this.doSomeStuff()
}
</code></pre>
<p>Do you thing this feature is worth it?</p>
<p>Any feedback is welcome.</p>
<p></p></div><div class="bloop_original_html"><style>body{font-family:Helvetica,Arial;font-size:13px}</style><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;"><br></div><br><div id="bloop_sign_1449555801022691840" class="bloop_sign"><div><font face="helvetica, arial">— </font></div><div>Regards Adrian<br></div></div></div><div class="bloop_markdown"><p></p></div></body></html>