Workers and Gangs both have criteria which governs whether they run or just pass through

[joelhelbling]

The criteria are basically just a series of callables which accept the target entity (gang or worker) and evaluate truthiness to determine whether to operate on incoming values or simply pass them through untouched.

[joelhelbling]

That's a seriously powerful way to do this, but ultimately they'd likely end up looking at the worker's tags I think...couldn't run criteria be done as a series of hash-like matchers? e.g.

[
  { tags_any: 'foo' },
  { tags_none: /bar/ }
]