The SitePoint PHP blog has a new tutorial posted from author Christopher Pitt continuing on his look at macros in PHP (part one is here). In this new tutorial he gets beyond the basic example he provided in part one and recreate some expressive syntax from Javascript and prefixing strings.

I was so excited about my previous article about PHP macros, that I thought it would be fun for us to explore the intersection of macros and functional programming. PHP is already full of functions, with object oriented patterns emerging relatively late in its life. Still, PHP’s functions can be cumbersome, especially when combined with variable scope rules…

[...] It’s not significantly more code [to append the prefix in PHP vs Javascript], but it isn’t as clear or idiomatic as the JavaScript alternative. I often miss JavaScript’s expressive, functional syntax, when I’m building PHP things. I want to try and win back some of that expressive syntax!

He starts with a quick install of the yay library used in the first part of the series. Instead of the manual prefixing from his first example, he creates a macro that uses the array_map handling to generate the necessary code once the pre-compiler has done its job. He then expands on this simpler solution and updates it to allow for the setting of the prefix string. It gets a little complex but he walks through each step of the way, explaining the code that's added and what it expands out to. The result is a map method that generates a bit of code that's eval-ed to handle the prefixing automatically.

On the SitePoint PHP blog they've posted another tutorial from Christopher Pitt, this time about macros in PHP, and how you can use the Yay library to add in custom pre-processed macros to your code.

I get really excited when developers feel empowered to create new tools, and even new languages with which to solve their problems. You see, many developers come to PHP from other languages. And many PHP developers can code in more than one language. Often there are things in those languages — small syntax sugars — that we appreciate and even miss when we’re building PHP things.

Adding these to a language, at a compiler level, is hard (or is it?). That is unless you built the compiler and/or know how they work. We’re not going to do anything that technical, but we’re still going to be empowered.

He starts off by describing the goal: a simple "range" macro that creates an array and fills it with integers. He helps you get the library installed and shows how to use it to pre-process a file and output the PHP version. He shows how to create the syntax for the macro in the format Yay is expecting for the array_slice shortcut. He also includes handling letting you slice out a portion of an array using the same notation. Finally he shows the resulting code after the pre-processing has happened and the macros have been resolved.