I am looking to find a way to make the following piece of code compile without having to declare an interface.
var a : <A>{ (value: A): void; (): A; } = null;
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Why can't you create a named interface? Is the operation so abstract you can't even name it?Bartek Banachewicz– Bartek Banachewicz2014-10-03 15:50:07 +00:00Commented Oct 3, 2014 at 15:50
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1I don't want to pollute the namespace with single-time-used interfaces.Trident D'Gao– Trident D'Gao2014-10-03 15:52:21 +00:00Commented Oct 3, 2014 at 15:52
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I haven't used TS in a while, but can't you do something like a local, "detail" namespace?Bartek Banachewicz– Bartek Banachewicz2014-10-03 15:53:05 +00:00Commented Oct 3, 2014 at 15:53
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1Of course I can come up with a workaround, but the question is about finding a way to avoid doing that.Trident D'Gao– Trident D'Gao2014-10-03 15:54:00 +00:00Commented Oct 3, 2014 at 15:54
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1TypeScript claims to support anonymous types, hence the question.Trident D'Gao– Trident D'Gao2014-10-03 15:56:24 +00:00Commented Oct 3, 2014 at 15:56
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1 Answer
It doesn't make sense for a generic type like that to even exist. It's the same reason you can't write Foo<T> x; in C++ without an actual T in scope -- once the type is manifest, it has to be bound.
You can write this instead, which probably has the semantics you wanted anyway.
var a: { <A>(value: A): void; <A>(): A; } = null;
If that's not what you were looking for, it'd be useful to post some examples of what valid and invalid calls on a would look like.
1 Comment
Trident D'Gao
It turned out that my case was
{ <A>(value: A): void; <B>(): B; }