On Tue, Feb 23, 2021, at 5:21 AM, Nikita Popov wrote:
> Hi internals,
>
> I'm a bit concerned about the addition of the "enum" reserved keyword as
> part of https://wiki.php.net/rfc/enumerations. The problem is that there
> are quite a few existing enum libraries (such as
> https://github.com/myclabs/php-enum) that define an Enum class. While the
> implementation of enums in PHP 8 obsoletes these libraries, it still
> constitutes a migration problem, especially for libraries supporting more
> than one PHP version.
>
> I don't believe that the keyword is strictly necessary: We can recognize
> enum declarations as T_STRING T_STRING, where the former is checked to be
> equal to "enum" by the parser. It so happens that this is syntactically
> unambiguous at this time. We may be forced to introduce the keyword at a
> later time, if it becomes ambiguous.
>
> Another possibility would be to recognize T_ENUM in the lexer, but only if
> it is followed by whitespace and an identifier. This would possibly be
> friendlier for tooling using token_get_all(). It would not permit comments
> in between the tokens though.
>
> Thoughts?
>
> Regards,
> Nikita
If I understand correctly, neither of these proposals would change the user-facing syntax, right? Just the parser details?
I'm fine with that as a transition plan. I think long-term it's better to have all keywords behave the same, but if we could use one of these alternates for now and then switch to a normal T_ENUM in 9.0 (thus not breaking a class named Enum until then) I'd be fine with that.
I can't see a comment between "enum" and "Suit" being useful, so that's an acceptable tradeoff for me.
--Larry Garfield
