Range

The Range component provides a way to create a range of integer values.

Ranges represent sets of integer values with optional lower and upper bounds. They support containment checks, iteration, and bound manipulation.

Usage

Creating Ranges

There are four types of ranges, created with constructor functions:

use Psl\Range;

$range = Range\from(0); // 0..   (from 0 to infinity)
$range = Range\to(10); // ..10  (up to 10, exclusive)
$range = Range\to(10, true); // ..=10 (up to 10, inclusive)
$range = Range\between(0, 10); // 0..10 (from 0 to 10, exclusive)
$range = Range\between(0, 10, true); // 0..=10 (from 0 to 10, inclusive)
$range = Range\full(); // ..    (all integers)

Containment Checks

All range types support contains():

use Psl\Range;

$range = Range\between(0, 10);
$range->contains(5); // true
$range->contains(100); // false

$range = Range\from(0);
$range->contains(5); // true
$range->contains(100); // true

$range = Range\full();
$range->contains(5); // true
$range->contains(100); // true

Iterating Over Ranges

Ranges with a lower bound (FromRange and BetweenRange) are iterable:

use Psl\Range;

$range = Range\between(0, 5);

$range = Range\between(0, 5, true);

// FromRange is iterable but infinite -- use with care
$range = Range\from(0);
foreach ($range as $value) {
    // $value is 0, 1, 2, 3, ...
    if ($value > 100) {
        break;
    }
}

Manipulating Bounds

Ranges can be combined with new bounds to create different range types:

use Psl\Range;

// Add an upper bound to a FromRange
$from = Range\from(0);
$between = $from->withUpperBoundInclusive(10);
// Now a BetweenRange: 0..=10

// Remove the lower bound
$to = $between->withoutLowerBound();
// Now a ToRange: ..=10

// Add a lower bound to a ToRange
$between = $to->withLowerBound(5);

// Now a BetweenRange: 5..=10

See src/Psl/Range/ for the full API.