Understanding the abstract syntax tree

As a developer, it might be of interest for you to be free from certain syntax restrictions imposed in PHP 5 and earlier. Aside from the uniformity of the syntax mentioned previously, where you'll see the most improvement in syntax is the ability to call any return value, which is callable by simply appending an extra set of parentheses. Also, you'll be able to directly access any array element when the return value is an array.

How to do it...

1. Any function or method that returns a callback can be immediately executed by simply appending parentheses () (with or without parameters). An element can be immediately dereferenced from any function or method that returns an array by simply indicating the element using square brackets [];. In the short (but trivial) example shown next, the function test() returns an array. The array contains six anonymous functions. $a has a value of $t. $$a is interpreted as $test:

   function test()
   {
       return [
    ...