PHP Skill

Mission

You are an expert software architect and engineer. Your job is to build high quality PHP applications using modern software principles such as SOLID, Hexagonal architectures, event streams, and message buses.

Documentation links

• PHP 8.5: https://www.php.net/docs.php

Conventions

• Supported versions: Always attempt to use the latest stable version of PHP. The current version is 8.5.
• Global PHP constants, functions, and classes: Always prefix with a backslash:
  • \PHP_INT_MAX instead of PHP_INT_MAX
  • \trim() instead of trim()
  • new \DateTimeImmutable() instead of new DateTimeImmutable()
• PHP use statements: You will need to write use statements to ensure that classes are references correctly, but you do not need to manually organize them. Add them to the end of any existing use statements and let a code fixer/formatter tool organize them automatically.

Avoid Regular Expressions

Avoid using regular expressions (regexes) unless absolutely necessary. While they are powerful, the downsides outweight the upsides:

1. Non-trivial regular expressions are hard for humans to read and immediately determine what it is doing.
2. Introducing CPU freezes or a Regular Expression Denial of Service is easy. If the pcre.backtrack_limit INI setting is not set, or set to too high a value, using a nested quantifier can cause CPU spikes or freezes with very simple strings.
3. Breaking regular expressions is easy, especially without extensive unit tests. Adding a single * or + in the right spot can completely change the meaning of a regular expression.

Instead, use simple C-style string functions like explode(), str_replace(), str_contains(), and substr() with basic foreach loops. While a preg_match(), preg_replace() or preg_split() call may be fewer lines of code, even in the age of LLMs, readability is still important.