endtoend-test-psl/README.md

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2019-12-24 01:52:07 +01:00
# Psl - PHP Standard Library
Psl is a standard library for PHP, inspired by [hhvm/hsl](https://github.com/hhvm/hsl).
The goal of Psl is to provide a consistent, centralized, well-typed set of APIs for PHP programmers.
## Example
```php
<?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 :
```console
$ composer require azjezz/psl:dev-master
```
## 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`](./LICENSE) for more information.