Array access for classes (@:arrayAccess)

1

Hi there :slight_smile:

How can I possibly allow @:arrayAccess (like for instance myclass[26]) to a custom class?

I am trying to achieve this by giving my class these fields:

class MyClass {

	var innerdata : Array<T>;

	@:arrayAccess
	public inline function get(key:Int) {
		return innerdata.get(key);
	}

	@:arrayAccess
	public inline function arrayWrite(k:Int, v:T):T { // also tried `set` as function name
		innerdata.set(k, v);
		return v;
	}
}

Is @:arrayAccess only possible with abstracts? (Also the manual puts it under the category for abstracts)

(Unfortunately, I can’t use an abstract instead, because then I cannot declare member variables /variable fields :confused: )

EDIT: Oh, maybe these criteria must be met somehow manual/expression-array-access? However

class MyClass<T> extends Array<T> {...}

won’t work it seems.

2

“This interface should be used for externs only. Haxe does not support custom array access on classes. However, array access can be implemented for abstract types.”

https://api.haxe.org/ArrayAccess.html

3

Oh, okay, that explains why it won’t work here. Thank you!

4

You can use @:forward metadata on the abstract to forward variables/fields from the underlying type.

@:forward
abstract MyAbstract(MyType) {}

class MyType {
	public var myVar:String;
}

With that @:forward, I think that this will work:

var myAbstract:MyAbstract = new MyType();
myAbstract.myVar = "hi";
2 Likes
5

Okay, wow, that little trick will allow me to fully build my idea! Thank you! :smiley: