PHP: page 1
The lambda calculus for developers
This will be a quick introduction to the lambda calculus syntax, alpha (α) equivalence and beta (β) reduction. What does a lambda look like? I am going to use the identity function as an example for the simplicity it provides. This can be expressed as a lambda function with the notation λx.x. It is a function that when given an argument outputs that argument as its return value. You can also have multiple arguments with a lambda like λxy. Read more ⇒
PHP and immutability: objects and generalisation - part three
In the last article we learnt how to create modified copies of an immutable in PHP. This one is going to tackle an issue I have hitherto skirted around and avoided. Objects in immutable data structures. This article is part of a series I have written on the topic of immutability in PHP code: Part one - a discussion of caveats and a simple scalar handling immutable Part two - improve the process of creating modified copies of the immutable Part three - objects in immutable data structures and a generalised immutable implementation Also available in Русский (Russian): Read more ⇒
PHP and immutability: modified copies - part two
In the last article we learnt how to create an immutable data structure in PHP. There were a few issues to work through, but we got there in the end. Now onto making the immutable class more useful and easier to create modified copies. Note that these are copies and not modifications, in-place, to the original objects. This article is part of a series I have written on the topic of immutability in PHP code: Read more ⇒
PHP and immutability: difficulties and scalars - part one
Being a weakly typed dynamic language, PHP has not really had the concept of immutability built into it. We’ve seen the venerable define() and CONSTANTS of course, but they’re limited. Whilst PHP does ship with an immutable class as part of it’s standard library, DateTimeImmutable, there is no immediately obvious method to create custom immutable objects. This article is part of a series I have written on the topic of immutability in PHP code: Read more ⇒
Quick way to create a PHP stdClass
A very short and simple trick for creating new stdClass objects without having to set every property individually. This is akin to JavaScript’s object notation, but not quite as elegant. Creating a new object in JavaScript looks like the following example. const x = { a: "test", b: "test2", c: "test3", }; With PHP it is possible to use type casting to convert a simple array into a stdClass object which gives you a similar looking syntax although there is a little more typing required. Read more ⇒
Functional Programming in PHP Second Edition Available Now
It is with great pleasure that I announce the second edition of the Functional Programming in PHP book that I have been working on. There is twice the content of the first edition of the book as well as updates for PHP 7 and Facebook’s HHVM (HipHop Virtual Machine). There are now more functional techniques and patterns included with pipelines, pattern matching and flat maps among them. I have added a section of the book dedicated to the handy syntax and functionality that HHVM can provide functional programmers with. Read more ⇒
Importing and aliasing PHP functions
As a follow on to my short post about namespaces and functions from a year ago I thought it would be worth covering importing a specific function and aliasing functions via namespace operators too. This has been possible since PHP 5.6, but there is a nice addition in PHP 7 I’ll cover towards the end. In the previous article I demonstrated how you can namespace functions and use them, but as a refresher; you can enclose functions within a namespace just like a class. Read more ⇒
With the release of PHP 5.3 namespaces became a reality in PHP and they’ve made so much possible including better autoloading. The majority of the time you’ll be used to seeing them at the top of each class file. They can also be used to namespace functions however. A standard PHP namespace declaration would look similar to the following at the top of a class file. namespace Treffynnon\Html; class Tag { // . Read more ⇒
When you’re working in a team you need ways to easily share and denote good style and taste. This is true of your primary programming language with PEP8 for Python and PSRs 1 & 2 for PHP being well known. There is probably even a style guide for HTML and CSS set out at your company. So why should SQL miss out on the party? I have written a style guide for SQL to promote a consistent code style ensuring legible and maintainable projects - sqlstyle. Read more ⇒
International PHP dates with intl
I wrote about localising dates (and other data) in a recent blog post, but unfortunately there were some shortcomings where time zones were concerned. As I alluded to in that post there is a way around this via the Intl extension that exposes a simple API to format DateTime instances. Thankfully this follow up post will be quite short as the setup is very simple for those of you on Ubuntu/Debian you can use the repositories. Read more ⇒