itertools\ZipIterator

Complexity

Total Complexity

14

Size/Duplication

Total Lines	60
Duplicated Lines	0 %

Coupling/Cohesion

Components	1
Dependencies	1

Importance

Changes

0

7 Methods

Rating	Name	Duplication	Size	Complexity
A	__construct()	0	10	3
A	newFromArguments()	0	5	1
A	rewind()	0	7	2
A	key()	0	4	1
A	current()	0	8	2
A	next()	0	6	2
A	valid()	0	8	3

<?php

namespace itertools;

use Iterator;
use InvalidArgumentException;

/**
 * Inspired by pythons [zip](http://docs.python.org/3.1/library/functions.html#zip) function. It
 * can be constructed with an array of iterators and it iterates all of its arguments at the index,
 * returning during each iteration an array of the elements of each iterator on the same iteration positon
 *
 * Example:
 *     $csv1 = new FileCsvIterator('file1.csv');
 *     $csv2 = new FileCsvIterator('file2.csv');
 *     foreach(new ZipIterator(array($csv1, $csv2)) as $combinedRows) {
 *         $row1 = $combinedRows[0]; // a row in file1.csv
 *         $row2 = $combinedRows[1]; // row in file2.csv on same position
 *     }
 */
class ZipIterator implements Iterator
{
	protected $iterators;
	protected $iterationCount;

	public function __construct(array $iterators)
	{
		if(count($iterators) == 0) {
			throw new InvalidArgumentException('Cannot construct a ZipIterator from an empty array of iterators');
		}
		$this->iterators = array();
		foreach($iterators as $iterator) {
			$this->iterators[] = IterUtil::asIterator($iterator);
		}
	}

	public static function newFromArguments()
	{
		$iterators = func_get_args();
		return new self($iterators);
	}

    public function rewind()
	{
		$this->iterationCount = 0;
		foreach($this->iterators as $iterator) {
			$iterator->rewind();
		}
    }

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

    public function current()
	{
		$currentValues = array();
		foreach($this->iterators as $iterator) {
			$currentValues[] = $iterator->current();
		}
		return $currentValues;
    }

    public function next()
	{
		foreach($this->iterators as $iterator) {
			$iterator->next();
		}
    }

    public function valid()
	{
		$valid = true;
		foreach($this->iterators as $iterator) {
			$valid = $iterator->valid() && $valid;
		}
		return $valid;
    }
}