> If you're going to optimize with closures, why not go a step further and pull the conditional out of the closure? You could instead have a conditional in the

> If you're going to optimize with closures, why not go a step further and pull the conditional out of the closure? You could instead have a conditional in the function that produces the right closure based on mode rather than constantly re-checking mode every single time you call the closure. I tend to try and do that in any language as soon as a single conditional means a change in behaviour in different locations, regardless of optimization concerns. It makes for (IMHO) more robust code and much easier testing (though you need more mocks).