phel-lang/phel-lang

Phel is a functional programming language that compiles to PHP

v0.31.0 2026-04-03 12:17 UTC

Requires

• php: >=8.3
• gacela-project/gacela: ^1.12
• phpunit/php-timer: ^6.0|^7.0|^8.0
• symfony/console: ^6.0|^7.0|^8.0

Requires (Dev)

• ext-readline: *
• ergebnis/composer-normalize: ^2.50
• friendsofphp/php-cs-fixer: ^3.94
• phpbench/phpbench: ^1.6
• phpstan/phpstan: ^2.1
• phpunit/phpunit: ^10.5
• psalm/plugin-phpunit: ^0.19
• rector/rector: ^2.3
• symfony/var-dumper: ^7.4
• vimeo/psalm: ^6.16

MIT

• Jens Haase
• Jose M. Valera Reales

• language
• functional
• lisp
• phel

README

Phel is a functional, Lisp-inspired programming language that compiles to PHP. It brings the expressive power of Clojure and the simplicity of Janet to the PHP ecosystem — enabling you to write concise, immutable, and composable code that runs anywhere PHP does.

Example

; Define a namespace
(ns my\example)

; Define a variable with name "my-name" and value "world"
(def my-name "world")

; Define a function with name "print-name" and one argument "your-name"
(defn print-name [your-name]
  (print "hello" your-name))

; Call the function
(print-name my-name)

Documentation

Getting Started

• Quick Start Tutorial Get up and running in 5 minutes with your first Phel application.
• Installation Detailed installation guide and project setup.

Learning Resources

• Clojure Migration Guide Coming from Clojure? Key differences, interop cheat sheet, and what's the same.
• Common Patterns Idiomatic Phel code patterns for everyday tasks.
• PHP/Phel Interop Complete guide to working between PHP and Phel code.
• Reader Shortcuts Reference for all special syntax and reader macros.
• Reader Conditionals Cross-platform code with #?(), #?@(), and .cljc files.
• Transducers Composable transformation pipelines without intermediate collections.
• Data Structures Guide to Phel's persistent, immutable collections.
• Lazy Sequences Performance patterns and common pitfalls.
• Mocking Guide Testing with mocks and test doubles.
• Examples Runnable code samples covering key features.

Reference

• Website Official website with tutorials, exercises, and blog posts.
• Packagist Official PHP package repository.
• Internals Deep dive into the compiler architecture.
• Repository Guidelines Project structure, modules, build commands, and review expectations.

Build PHAR

Run the following command to create a standalone PHAR executable:

./build/phar.sh

The generated build/out/phel.phar can then be executed directly.

Contribute

Resource	What's there
CONTRIBUTING.md	Setup, workflow, testing, and PR guidelines
Repository Guidelines	Architecture, modules, build commands, review expectations
docs/	Guides, examples, and compiler internals
phel-lang.org	Tutorials, exercises, and blog posts

New here? Start with CONTRIBUTING.md — it explains the two-language codebase and has a "Where to Start" section based on your interests.