library phlip

webgraphe/phlip

Embeddable scripts for PHP

Embeddable scripts for PHP

, _(*1)

Phlip (pronounced \ˈflip\) is an embeddable scripting language for PHP based on s-expressions., _(*2)

How does it work?

A lexer tokenizes scripts and a parser assembles data structures. A script's behavior originates from data and code elements resolved from a controlled scope., _(*3)

Integration is simpler with the Phlipy dialect., _(*4)

Refer to Webgraphe\Phlip\Tests\Unit\ReadmeTest for the example below:, _(*5)

<?php

use Webgraphe\Phlip\Phlipy;
use Webgraphe\Phlip\Program;

// Tokenize and parse code into a program
$program = Program::parse('(lambda (x) (* x x))');
// Bootstrap a new scope with different level of Phlipy dialects
$scope = Phlipy::basic()->getScope();
// Execute program within said scope
$square = $program->execute($scope);

// In this case, return value is an anonymous function - a lambda - calculating the square of a number
// as per source code "(* x x)"
var_dump($square(M_PI)); // (double)9.8696044010894

How to install

Add a dependency on your projects with Composer, using composer require webgraphe/phlip. You may also install it globally with composer global require webgraphe/phlip., _(*6)

Why use Phlip

• Embeddable scripts mean data becomes code
• Easy to use
• Easy to learn
• Build your own dialect!
• Interoperable with PHP Classes
• Create test suites with phlipunit (built on top of PHPUnit)
• Ships with a literal REPL (loop (print (eval (read))))

DISCLAIMER, _(*7)

Lisp is a often considered a Homoiconic (code as data) language. Despite Phlip's usage of S-expressions and a somewhat successful attempt at reproducing McCarthy's eval, as the author I do not consider Phlip be an homoiconic language as it relies on PHP's internal data structures such as array, stdClass, native scalars, Closure and invokable classes for performance and convenience., _(*8)

Phlip is embeddable in PHP and was built to allow transportation of code and data in a manner that can stay relatively secure, provided that functionalities interoperable with PHP stay in check., _(*9)

For reference: Webgraphe\Phlip\Tests\System\LispTest::testMcCarthyEval(), _(*10)