Re: [RFC] [Discussion] Shorter Attribute Syntax Change

Hi internals, I had thought of another alternative syntax - /** @@MyAttribute */, which would solve some of the problems I mentioned about #[. ``` namespace My\NS; use Other\MyAttribute; /** * Use @@ or << at the start of a line. (To be determined) * Resolve the names in the comment relative to the scope of the function, like the current attribute implementation.  * @@MyAttribute(expr, expr) * Extra *s are allowed *** @@AnotherAttribute * Tokenizing should continue until a matching ) is found * @@YetAnotherAttribute( * expr *)  */ function my_function() { } ``` Pros: - Doc comments are already the recommended way to associate information with a named element. - Most code modifying tools will preserve doc comments - This can go on the same line as a closure/short arrow function without lexing ambiguity. - Frameworks can use Reflection*->getDocComment() and update their checks to also allow @@ for attribute-like annotations when run in PHP 7. They don't have to repeat both @@MyAttribute and /** @MyAttribute */ or risk it going out of sync (Symfony would already have to parse the use clauses to find out what @MyAttribute resolves to for Symfony attributes) - Does not affect lexing outside of the doc comment - I don't believe @@ is common. To minimize the impact on ascii art, this can be initially limited to @@ at the start of a comment line (spaces and *s) immediately followed by \ or the start of an identifier Cons: - Need to run the lexer twice on a T_DOC_COMMENT token, but only if the comment string contains @@ and is associated with an element. Emitting T_DOC_COMMENT_START and T_DOC_COMMENT_END and T_DOC_COMMENT_INNER and T_DOC_COMMENT_ATTRIBUTE T_DOC_COMMENT_ATTRIBUTE_ERROR might make this technically feasible (similar to heredoc having complicated logic) - I prefer @@ and <<>> over this proposal long-term, after php 7.4 support is dropped. But I prefer /** @@MyAttr */ over #[MyAttr]. - Would end up emitting parse errors for some existing code in the second lexer pass. - Syntax highlighting might be hard to implement in editors, but probably tractable. I don't remember seeing this proposed before. I believe @@ isn't used by mainstream frameworks in doc comments right now, but correct me if it is. Thanks, - Tyson