Online PHP editor | output for 43gn2

<?php namespace Test; class SegmentContainer { private $fooSegmentArray = []; private $barSegmentArray = []; public function __construct(array $fooSegmentArray, array $barSegmentArray) { $this->fooSegmentArray = $fooSegmentArray; $this->barSegmentArray = $barSegmentArray; } public function popFooSegment() { return array_pop($this->fooSegmentArray); } public function shiftBarSegment() { return array_shift($this->barSegmentArray); } } /** * I provide a unified interface to reading the segments, one at a time */ interface SegmentReaderInterface { function readSegment(); } /** * I encapsulate a SegmentContainer, my derivatives determine how to * read from it. */ abstract class SegmentReaderBase implements SegmentReaderInterface { private $segmentContainer; public function __construct(SegmentContainer $segmentContainer) { $this->segmentContainer = $segmentContainer; } public function getSegmentContainer() { return $this->segmentContainer; } } class FooSegmentReader extends SegmentReaderBase { public function readSegment() { return $this->getSegmentContainer()->popFooSegment(); } } class BarSegmentReader extends SegmentReaderBase { public function readSegment() { return $this->getSegmentContainer()->shiftBarSegment(); } } /** * I don't care whether I end up reading from the $fooSegmentArray or * the $barSegmentArray, nor the direction from which I'm reading it. * I just want to be able to read them, one at a time. */ function acceptSegmentReader(SegmentReaderInterface $segmentReader) { var_dump($segmentReader->readSegment()); var_dump($segmentReader->readSegment()); } $segmentContainer = new SegmentContainer(['a', 'b', 'c'], ['1', '2', '3']); acceptSegmentReader(new FooSegmentReader($segmentContainer)); acceptSegmentReader(new BarSegmentReader($segmentContainer)); var_dump($segmentContainer);