26 lines
591 B
Plaintext
26 lines
591 B
Plaintext
// version 1.1.51
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interface Thingable {
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fun thing(): String?
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}
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class Delegate(val responds: Boolean) : Thingable {
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override fun thing() = if (responds) "delegate implementation" else null
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}
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class Delegator(d: Delegate) : Thingable by d {
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fun operation() = thing() ?: "default implementation"
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}
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fun main(args: Array<String>) {
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// delegate doesn't respond to 'thing'
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val d = Delegate(false)
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val dd = Delegator(d)
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println(dd.operation())
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// delegate responds to 'thing'
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val d2 = Delegate(true)
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val dd2 = Delegator(d2)
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println(dd2.operation())
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}
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