PHP RFC: ReflectionType Improvements

• Version: 1.0
• Date: 2016-06-10
• Author: Levi Morrison levim@php.net
• Status: Draft
• First Published at: https://wiki.php.net/rfc/ReflectionTypeImprovements

For PHP 7.0 the ReflectionType API was introduced in conjunction with return types. Its minimal API was intended to be the base for future improvements; this RFC contains those improvements.

This RFC adds several new subtypes for ReflectionType; here is their stubs:

class ReflectionSingularType extends ReflectionType {
    public function getName(): string;
}
 
class ReflectionClassType extends ReflectionSingularType {
    public function getClass(): ReflectionClass;
}

If the engine does not recognize a type it will call the autoloader; if the class is found then a ReflectionClassType will be returned and otherwise a plain ReflectionSingularType will be returned.

A call to the getName() method of a ReflectionSingularType that represents any of int, ?int or int $foo = null will return int in each case. Note that the __toString method would return int, ?int and ?int respectively.

There is a change for ReflectionType::__toString() which will now include a ? for nullable types. This change is justified for several reason:

1. ReflectionType was introduced in 7.0 and therefore adoption is low
2. The change reflects the intention of the meaning of __toString to be the string representation of the type that would pass syntax checking. Unfortunately this intention wasn't formally documented thus classifying this as a BC break.

This RFC targets PHP 7.Next which is currently version 7.1.

ReflectionClass is unaffected; this only touches ReflectionType.

It is unclear if voting requires 50%+1 or 2/3. On one hand this is not a language change but on the other this does contain a BC break. Rather than debating it one way or the other I've chosen to require 2/3.

The vote will be a simple yes or no for these changes.

The patch for this is not difficult; it will be coming soon.