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.

2.3 Comparing elements

Some methods of Collection involves comparing two of its elements, which accepts $flags as one of its arguments.

When these methods are being invoked, type of the very first element of the Collection represents that of all other ones. Make sure all elements are of the same type (numeric/string/others), otherwise you're likely to get a segfault.

2.4 Notes

• The Collection::xxxTo() methods will preserve the original key-value pairs of destination Collection when keys collide.

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'].