Request for Comments: How to write RFCs

• version 1.0
• Date: 2013-01-28
• Author: Levi Morrison levim@php.net
• Status: Under Discussion

Currently if you have a class that implements Iterator in such a way that key returns a non-scalar, you get a warning when using it in a foreach loop. The value of the key is cast to an integer if it is not a scalar.

<?php
 
class MapIterator implements Iterator {
    protected $vals = [];
    protected $keys = [];
    protected $index = 0;
 
    function __construct(array $keys, array $values) {
        $this->keys = $keys;
        $this->vals = $values;
    }
 
    function rewind() {
        $this->index = 0;
    }
 
    function valid() {
        return $this->index < count($this->keys) && $this->index >=0;
    }
 
    function key() {
        return $this->keys[$this->index];
    }
 
    function current() {
        return $this->vals[$this->index];
    }
 
    function next() {
        $this->index++;
    }
 
}
 
$requestA = new StdClass;
$requestA->startLine = 'GET / HTTP/1.1';
$requestA->headers = ['Host' => 'www.php.net'];
 
$responseA = new StdClass;
$responseA->startLine = 'HTTP/1.1 200 OK';
$responseA->headers = [];
 
$requestB = new StdClass;
$requestB->startLine = 'GET /login HTTP/1.1';
$requestB->headers = ['Host' => 'www.php.net'];
 
$responseB = new StdClass;
$responseB->startLine = 'HTTP/1.1 302 Found';
$responseB->headers = ['Location' => 'http://www.php.net/account/login'];
 
$requests = [$requestA, $requestB];
$responses = [$responseA, $responseB];
 
$mapIterator = new MapIterator(
    $requests,
    $responses
);
 
foreach ($mapIterator as $request => $response) {
    var_dump($request);
    var_dump($response);
}

Yields a warning Warning: Illegal type returned from MapIterator::key() in ... and var_dump($request); returns int(0).

I propose that we lift the restriction that forces a scalar value. Instead we simply assign the key variable to whatever was returned from the iterator. The warning will also be removed.

There is no patch at this time. I know Ekneuss was working on something but hasn't had time to finish.

version 1.0:

• proposed