Describe an immediate function to read easily.

run.js

/**
 * Runs the function immediately.
 * @param {Array} [args] Arguments for the function.
 * @param {Object} [context] Context for the function.
 * @param {Function} fn Target function.
 * @returns {Any} Value returned by the function.
 * @example run(function(){ console.log('done!'); });
 * @example run([1,2], function(a,b){ return a+b; });
 * @example var date = Date.now(); run([Date.now()], {start:date}, function(stop){ return stop-this.start; });
 */
function run(args, context, fn) {
  if (!fn) { fn = context; context = undefined; }
  if (!fn) { fn = args; args = undefined; }
  if (fn && fn.apply) { return fn.apply(context, args); }
}