Function link

src/system.ts:51–91

(dep: ReactiveNode, sub: ReactiveNode, version: number)

	};

	function link(dep: ReactiveNode, sub: ReactiveNode, version: number): void {
		const prevDep = sub.depsTail;
		if (prevDep !== undefined && prevDep.dep === dep) {
			return;
		}
		const nextDep = prevDep !== undefined ? prevDep.nextDep : sub.deps;
		if (nextDep !== undefined && nextDep.dep === dep) {
			nextDep.version = version;
			sub.depsTail = nextDep;
			return;
		}
		const prevSub = dep.subsTail;
		if (prevSub !== undefined && prevSub.version === version && prevSub.sub === sub) {
			return;
		}
		const newLink
			= sub.depsTail
			= dep.subsTail
			= {
				version,
				dep,
				sub,
				prevDep,
				nextDep,
				prevSub,
				nextSub: undefined,
			};
		if (nextDep !== undefined) {
			nextDep.prevDep = newLink;
		}
		if (prevDep !== undefined) {
			prevDep.nextDep = newLink;
		} else {
			sub.deps = newLink;
		}
		if (prevSub !== undefined) {
			prevSub.nextSub = newLink;
		} else {
			dep.subs = newLink;
		}
	}

	function unlink(link: Link, sub = link.sub): Link | undefined {
		const { dep, prevDep, nextDep, nextSub, prevSub } = link;