How to define an asynchronous callback?

[gamecubate]

I'm not clear on how to define asynchronous callbacks. I tried the function (gotData) below but that doesn't work (never gets invoked).

(d3.csv CSV gotData)

(var gotData
  (function (err data)
    (if err
      (throw err)
      (console.log data))))

Thanks in advance.

[santoshrajan]

Try

    (d3.csv CSV
      (function (err data)
        (if err
          (throw err)
          (console.log data))))

[gamecubate]

It works! Correct me if I'm wrong but does that imply that only anonymous functions can be used for callbacks, i.e., there is no way to declare the handler separately, within a separate function definition?