PHP RFC: Your Title Here

• Version: 0.1
• Date: 2015-02-02
• Author: Niklas Keller, me@kelunik.com
• Status: Draft
• First Published at: http://wiki.php.net/rfc/in_operator

This RFC adds a new in operator. It simplifies contains checks for strings and arrays and checks for accessible properties in objects.

Add a new operator (expr1) in (expr2). For strings and arrays, it checks whether expr2 contains expr1.

$contains = "foo" in ["a", "b", "c"]; // false
$contains = "foo" in ["foo", "bar"]; // true
$contains = "foo" in "foobar"; // true
$contains = "php" in "foobar"; // false

For objects, it works a bit differently, it checks if expr1 is a accessible property name of the expr2.

$stdClass = new StdClass;
$stdClass->foo = "bar";
$contains = "foo" in $stdClass; // true
$contains = "bar" in $stdClass; // false

New reserved keyword in.

Next major release, at the time of writing PHP 7.

Describe the impact to CLI, Development web server, embedded PHP etc.

Will existing extensions be affected?

It is necessary to develop RFC's with opcache in mind, since opcache is a core extension distributed with PHP.

Please explain how you have verified your RFC's compatibility with opcache.

A T_IN constant for use with ext/tokenizer has been added.

Make sure there are no open issues when the vote starts!

List existing areas/features of PHP that will not be changed by the RFC.

This helps avoid any ambiguity, shows that you have thought deeply about the RFC's impact, and helps reduces mail list noise.

None.

Requires a 2/3 majority.

Links to any external patches and tests go here.

If there is no patch, make it clear who will create a patch, or whether a volunteer to help with implementation is needed.

Make it clear if the patch is intended to be the final patch, or is just a prototype.

After the project is implemented, this section should contain

1. the version(s) it was merged to
2. a link to the git commit(s)
3. a link to the PHP manual entry for the feature

Links to external references, discussions or RFCs

Keep this updated with features that were discussed on the mail lists.