endtoend-test-psl/README.md
2020-07-06 19:35:34 +01:00

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Psl - PHP Standard Library

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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\Str;
use Psl\Iter;

/**
 * @psalm-param iterable<?int> $codes
 */
function foo(iterable $codes): string
{
    return Str\join(Iter\map(
        Iter\filter_nulls($codes), fn($i) => Str\chr($i),
    ), ', ');
}

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

Installation

This package doesn't not 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)

License

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