use alcamo\range\NonNegativeRange;

$range = NonNegativeRange::newFromString('3-7');

foreach ([-1, 0, 2, 3, 5, 7, 8] as $value) {
    echo "contains $value: " . $range->contains($value) . "\n";
}

This will output:

contains -1: 0
contains 0: 0
contains 2: 0
contains 3: 1
contains 5: 1
contains 7: 1
contains 8: 0

Provided interfaces, traits and classes

The interface RangeInterface provides a very basic interface for ranges of any kind.
The trait RangeTrait provides a simple implementation which covers most of what is needed for RangeInterface.
The class NonNegativeRange provides an implementation of a range of nonnegative integers, potentially unbounded from above, including the bound(s).