A map that tracks length

AMap.hx

package;

typedef TMap<A, B> = {
	var length:Int;
	var data:Map<A, B>;
}

@:forward abstract AMap<A, B>(TMap<A, B>) {
	public var length(get, never):Int;

	public function new(input) {
		this = input;
	}

	public function set(key:A, value:B) {
		this.data.set(key, value);
		if (!this.data.exists(key)) {
			this.length++;
		}
	}

	public function get(key:A) {
		if (this.data.exists(key)) {
			return this.data.get(key);
		}
		return null;
	}

	@:arrayAccess public inline function getString(key:A) {
		return this.data.get(key);
	}

	@:arrayAccess inline function setString(key:A, value:B) {
		this.data.set(key, value);
		if (!this.data.exists(key)) {
			this.length++;
		}
		return value;
	}

	public function exists(key:A):Bool {
		return this.data.exists(key);
	}

	public function remove(key:A):Bool {
		if (this.data.remove(key)) {
			this.length--;
			return true;
		}

		return false;
	}

	public function keys() {
		return this.data.keys();
	}

	public function iterator() {
		return this.data.iterator();
	}

	public function keyValueIterator() {
		return this.data.keyValueIterator();
	}

	public function toArray():Array<B> {
		var data = [];
		if (this == null || this.data == null) {
			return [];
		}

		for (item in this.data) {
			data.push(item);
		}

		return data;
	}

	@:from static function fromMap<A, B>(input:Map<A, B>) {
		var counter = 0;
		for (key => _ in input) {
			counter++;
		}

		return new AMap({
			length: counter,
			data: input
		});
	}

	private function get_length():Int {
		return this.length;
	}
}