·

1.727K

· emirotin

Many libraries provide functions that accepts lots of arguments.
A standard solution to this is a single parameter that's options object.

subscribe = (options) ->
 defaults =
 async: false
 options = _.extend {}, defaults, options
 eventName = options.eventName
 fn = options.fn
 async = options.async
 ...

But often 95% of cases you need to pass 1 or 2 params (like event name and handler function) which is more readable in a normal way

subscribe = (eventName, fn) ->

Now a generic pattern for easily handling both cases with CoffeeScript

subscribe = () ->
 if arguments.length == 1
 {eventName, fn, async, whatEver} = arguments[0]
 else
 [eventName, fn, async, whatEver] = arguments 

This uses destructuring assignment for objects and arrays: http://jashkenas.github.io/coffee-script/#destructuring

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