When to Use Which: Map or Object, Set or Array, WeakMap or Map, Generator or Array, Regex or String Methods

Every tool in this module has a neighbour that does almost the same job. A Map sits next to the plain object, a Set next to the array, and a WeakMap next to the Map. A generator sits next to an array you build first, and a regex next to split and includes. Picking the wrong one rarely crashes. It makes code slow, leaky or hard to read, and nobody notices until the data grows.