I love this JavaScript pattern. It can also be used with objects and written with a fallback, e.g.:

const opNamesToFunctions = {
  op1: () => // ...
  op2: () => // ...
  // ...
}

const noop = () => undefined;

const op = opNamesToFunctions[opName] || noop;
return op();

It’s kind of a poor person’s pattern matching, but it works great and I find it much easier to read than switch blocks. It works especially well in TypeScript if you can strictly define the keys of the object with a union type. Glad to hear it’s more performant, too.

Oof. This must also have also affected parsers a lot, since there’s often a big switch in the lexer and another in the parser.

I am curious if they ever did fix the optimization issue in v8.