Set

Data structure which only holds unique values. Set is implemented as immutable array.

Construction

Use one of three available named constructors: empty, of or ofAll

Set::empty();

Set::of('first', 'second');

Set::ofAll(['alpha', 'beta']);

Methods

You can add new element, remove existing one and check if given $element exist with contains.

$set = Set::of('alpha');

$set2 = $set->add('beta');

$set3 = $set2->remove('beta');

$set->contains('alhpa'); // true

If given $element already exists in set, same instance will be returned.

You can also join two sets with union. The merged set will contain only unique values.

$set = Set::of('alpha');

$set2 = Set::of('alpha', 'beta');

$set->union($set2); // 'alpha', 'beta'

diff returns a set containing all the entries from set that are not present in given set:

$set = Set::of('alpha', 'beta', 'gamma');

$set = $set->diff(Set::of('beta', 'gamma', 'delta'));

// set is now Set::of('alpha');