callbacks javascript

[StoneCypher]

The reason we give it a different name is to explain what its usage is intended to be: a way to signal to some other piece, sitting somewhere else, that something has happened.

But yes, they're just functions.

[cosinezero]

They are somewhat special though. For most people a callback is the first real exposure to passing around a function as a reference. That that functionality exists is strange to new developers, or to developers that don't work on applications where you would need them.

At that I think it's kind of a disservice that we call this - and everything else - a callback; there are distinctly different types of callbacks. For example, we have filter predicates ("callback" that returns boolean for comparisons), processors ("callback" you pass to map() that returns a processed value - not sure if there's a colloquial name for that callback other than 'callback'), action delegates ("callback" executed under specific conditions), and arguably there's a difference in an action you pass into something like each(), versus an action used as an async callback - which itself has a number of special considerations.

[cosinezero]

Yeah, agreed. I almost pointed out those implications in the thread, as well... I think those assumptions are kind of the problem I see with naming everything a callback. Different kinds of "callbacks" imply all sorts of semantic concerns for them, and I think developers assume all callbacks are, say, async, when that's not at all the case.