add extension property delegate puzzlers #72
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TWiStErRob
reviewed
Jul 12, 2020
| * Extension functions and properties are independent of the receiver instance (like static Java methods) | ||
| * The delegate is an instance that handles getter/setter calls. | ||
| * For extension properties, this is a single shared delegate instance | ||
| * The extension is initialized independently of any instance, so the delegate can't use any instance properties |
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Add some variation on this info?
During normal usage the initialiser block is scoped to the class body, so it can capture
thisif necessary.
TWiStErRob
reviewed
Jul 12, 2020
| @@ -0,0 +1,6 @@ | |||
| Correct answer: **will not compile** | |||
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The explanation doesn't really point out why. Is it because the signature of lazy takes a ()->T, which makes MyClass instance not accessible, which is kind of implied in the last point?
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actually, having the instance available in the lambda wouldn't really help - that's actually the point of my second example.
I'll try to rephrase things a bit to make the issue clearer
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There is something to consider when using extension properties in combination with delegates.
I added 2 different versions of this puzzler that show the issue in slightly different ways. The custom delegate implementation might be a failed try to fix the problem of the other version.