ext-collections

1. Introduction

This PHP extension provides a set of useful functional-style operations on PHP arrays, which makes array manipulation simple and scalable.

Method names and functionalities are inspired by Kotlin.Collections.

1.1 Notes

• Requires PHP 7.1 and above.
• Thread safety:
  • Distinct objects: safe.
  • Shared objects: unsafe.

2. Documentation

2.1 Functionalities

See stubs directory for signature of all classes and methods of this extension, with PHPDoc. They can also serve as IDE helper.

2.2 PHP-style access

The Collection class implements ArrayAccess and Countable interface internally, you can treat an instance of Collection as an ArrayObject.

• The isset(), unset() keywords can be used on elements of Collection.
• Elements can be accessed via property and bracket expression.
• empty(), count() can be used on instance of Collection.
• Elements can be traversed via foreach() keyword.

2.4 Notes

• The Collection::xxxTo() methods will preserve the original key-value pairs of destination Collection when keys collide.
• Some methods of Collection involves comparing two of its elements, which accepts $flags as one of its arguments. When these methods are being invoked, make sure all elements are of the same type (numeric/string/others), otherwise you're likely to get a segfault.

3. Example

Here is a simple example for how to work with arrays gracefully using this extension.

$employees = [
    ['name' => 'Alice', 'sex' => 'female', 'age' => 35],
    ['name' => 'Bob', 'sex' => 'male', 'age' => 29],
    ['name' => 'David', 'sex' => 'male', 'age' => 40],
    ['name' => 'Benjamin', 'sex' => 'male', 'age' => 32]
];
// Trying to get an array of names of male employees,
// sorted by the descending order of their age.
$names = Collection::init($employees)
    ->filter(function ($value) {
        return $value['sex'] == 'male';
    })
    ->sortedByDescending(function ($value) {
        return $value['age'];
    })
    ->map(function ($value) {
        return $value['name'];
    })
    ->toArray();
// You got $names == ['David', 'Benjamin', 'Bob'].