SimpleArray.php

<?php

class SimpleArray implements Iterator, ArrayAccess, Countable {

	private $size = 1;

	private $buffer = null;

	private $index = 0;

	private $position = 0;

	public function __construct($size = 1, $initial_value = 0) {
		$this->size = $size;
		$this->buffer = new SplFixedArray($size);
		for ($i = 0; $i < $size; ++$i) $this->buffer[$i] = $initial_value;
	}

	public function getSize() {
		return $this->size;
	}

	public function setIndex($i) {
		$this->index = $i;
	}

	public function seek($index) {
		while($this->position < $index && $this->valid()) {
			$this->next();
		}
		if (!$this->valid()) {
			throw new OutOfBoundsException('Invalid seek position');
		}
	}

	public function rewind() {
		$this->index = 0;
		$this->position = 0;
	}

	public function current() {
		return $this->buffer[$this->index+$this->position];
	}

	public function key() {
		return $this->position;
	}

	public function next() {
		++$this->position;
	}

	public function valid() {
		return isset($this->buffer[$this->position]);
	}

	public function count() {
		return count($this->buffer) - $this->index;
	}

	public function offsetExists($offset) {
		$offset += $this->index;
		return isset($this->buffer[$offset]);
	}

	public function offsetGet($offset) {
		$offset += $this->index;

		if (!isset($this->buffer[$offset]))
			throw new OutOfBoundsException('Index invalid or out of range.');

		return isset($this->buffer[$offset]) ? $this->buffer[$offset] : null;
	}

	public function offsetSet($offset, $value) {
		if (!isset($this->buffer[$offset]))
			throw new OutOfBoundsException('Index invalid or out of range.');

		$this->buffer[$offset] = $value;
	}

	public function offsetUnset($offset) {
		throw new \BadMethodCallException("Unset not implemented.");
	}

	public static function fromArray($array) {
		$l = count($array);
		$r = new SimpleArray($l);
		for ($i = 0; $i < $l; ++$i)
			$r[$i] = $array[$i];
		return $r;
	}

	public function toArray() {
		$l = $this->getSize();
		$r = array();
		for ($i = 0; $i < $l; ++$i)
			$r[$i] = $this->buffer[$i];
		return $r;
	}

}