Re: [RFC] Shorter attribute syntax

On Thu, June 4, 2020 at 5:37 AM Ilija Tovilo <tovilo.ilija@gmail.com> wrote: >>> Does the PHP parser prevent us from adopting #[attr]? I presume >>> C#'s [attr] syntax and C++'s [[attr]] are impossible due to >>> PHP's short array syntax. >> >> yes, that would create ambiguity in the parser since # >> (just >> like //) is for comments. > > I've mentioned this off-list before. If we consider @@ with a BC > break we could also consider #[] by making #[ a symbol. > This is also a breaking change but a probably similarly small one. > It would break code like this: > > # Comments still work > #[ <-- But they can't start with #[ > > To me both of those look acceptable but #[ looks nicer (but that's > just my personal preference). Hi Ilija, From the perspective of looks I don't have a strong preference between them. There are two main reasons the RFC doesn't propose the #[] syntax. First of all, I would consider this a larger BC break than @@. Although hash style comments are relatively uncommon, some codebases do use them, and I don't think we can presume to say that it "isn't useful" to begin a comment with a [ (as can be said about using multiple suppression operators). Secondly, the #[] syntax is 50% more verbose than the two character @@ proposal; Rust is the only language I found that uses three characters for its attribute syntax like this. ``` Best regards, Theodore