Function support callback and return style at once

Question

I am wondering about implementation of functionality like the following one.

As an input I receive a function, which could be either synchronous:

externalFunction = () ->
  return true

or asynchronous:

externalFunction = (done) ->
  done(true)

So, I want to distinguish those types of functions

When I receive a synchronous function, I want to call it and then use its results:

result = externalFunction()
doSomething result

And when I receive an asynchronous one, I want to wait for its callback first:

externalFunction (result) ->
  doSomething result

What is the best way to do it?

Right now I'm wondering about something like this:

promise(externalFunction(myCallback)).complete (err) -> ...

Thank you Leonid, just asked on mocha chat (mocha is using same logic) and they said, they are passing it like I did in my answer. — petomalina, Feb 17 '15 at 16:38

score 0 · Answer 1 · answered Feb 17 '15 at 15:38

0

This may be the simple answer, but still hoping for better one.

myCallbackAfterFunction = (result) ->
  ...

functions = [...]
for func in functions
  if func.length != 0
    func(myCallbackAfterFunction)
  else
    result = func()
    myCallbackAfterFunction(result)

answered Feb 17 '15 at 15:38

petomalina

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Am I right that you have an external function and you don't know if it is synchronous or asynchronous, so you want to support both variants? – Leonid Beschastny Feb 17 '15 at 15:49

Function support callback and return style at once

1 Answers1