export class Range {
	from;
	to;

	constructor(from: number, to: number) {
		this.from = from;
		this.to = to;
	}

	*[Symbol.iterator](): Generator<number, void, void> {
		let index = this.from;
		while (index < this.to) yield index++;
	}

	includes(n: number) {
		return (n > this.from) && (n < this.to);
	}
}

export function range(from: number, to: number) {
	return new Range(from, to);
}

Deno.test("range", async () => {
	const { assertEquals } = await import("https://deno.land/std@0.224.0/assert/assert_equals.ts");
	assertEquals([...range(0, 4)], [0, 1, 2, 3]);
});