Comment by jarek-foksa | Hacker News Reader

Comment by jarek-foksa | Hacker News Reader

If I understand correctly, everything after "await ..., defer" block will be executed only after the asynchronous operations from the await block are completed.

Does it mean that it's impossible to return any value from a function that contains await block?

  module = 
    dataPath: "http://search.twitter.com/search.json?q=blah&callback=?"

    init: () ->
      # Fetch data and do some stuff with it
      await 
        $.getJSON @dataPath, defer @data
  
      # Return yourself (this won't work)
      return @

There is a way around it. Here, everything after the await is transformed into a callback for the await magic:

    waity = (forFn) ->
      await forFn defer r1, r2
      console.log "values of defer variables", r1, r2
      return "this only returns from the result callback, not waity"

    syncReturn = waity (cb) ->
      setTimeout ->
        cb "r1 val", "r2 val"

    console.log "waity's synchronous return value:", syncReturn

So our output is:

    waity's synchronous return value: undefined
    values of defer variables r1 val r2 val

To return, you can simply write:

    waity = (forFn) ->
       setTimeout -> 
         await ...
       return "works as normal"

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