| /** | |
| * An auto-incrementing identifier for keys. | |
| */ | |
| let n = 0 | |
| /** | |
| * A class that keeps track of a key string. We use a full class here because we | |
| * want to be able to use them as keys in `WeakMap` objects. | |
| */ | |
| export class Key { | |
| id: string | |
| constructor() { | |
| this.id = `${n++}` | |
| } | |
| } | |