endtoend-test-psl/README.md

Psl - PHP Standard Library

Psl is a standard library for PHP, inspired by hhvm/hsl.

The goal of Psl is to provide a consistent, centralized, well-typed set of APIs for PHP programmers.

Example

<?php

declare(strict_types=1);

use Psl\Arr;
use Psl\Str;
use Psl\Iter;

/**
 * @psalm-param iterable<?int> $codes
 */
function foo(iterable $codes): string
{
    /** @var list<?int> $codes */
    $codes = Iter\to_array($codes);
    /** @var list<int> $codes */
    $codes = Arr\filter_nulls($codes);
    /** @var list<string> $chars */
    $chars = Arr\map($codes, fn(int $code): string => Str\chr($code));

    return Str\join($chars, ', ');
}

foo([95, 96, null, 98]);
// 'a, b, d'

Installation

This package doesn't have a stable release yet, but you can still install it using composer :

$ composer require azjezz/psl:dev-develop

Documentation

Documentation is not available yet.

Principles

• All functions should be typed as strictly as possible
• The library should be internally consistent
• References may not be used
• Arguments should be as general as possible. For example, for array functions, prefer iterable inputs where practical, falling back to array when needed.
• Return types should be as specific as possible
• All files should contain declare(strict_types=1);

Consistency Rules

This is not exhaustive list.

• Functions argument order should be consistent within the library
  • All iterable-related functions take the iterable as the first argument ( e.g. Iter\map and Iter\filter )
  • $haystack, $needle, and $pattern are in the same order for all functions that take them
• Functions should be consistently named.
• If an operation can conceivably operate on either keys or values, the default is to operate on the values - the version that operates on keys should have _key suffix (e.g. Iter\last, Iter\last_key, Iter\contains, Iter\contains_key )
• Find-like operations that can fail should return ?T; a second function should be added with an x suffix that uses an invariant to return T (e.g. Arr\last, Arr\lastx)
• Iterable functions that do an operation based on a user-supplied keying function for each element should be suffixed with _by (e.g. Arr\sort_by, Iter\group_by, Math\max_by)

Sponsors

Thanks to our sponsors and supporters:

JetBrains

License

The MIT License (MIT). Please see LICENSE for more information.