[ptx]

Apparently "foo(...)" is just the PHP syntax for a function reference, according to the "first-class callable" RFC [1] linked from the article.

So where in Python you would say e.g.

  callbacks = [f, g]

PHP requires the syntax

  $callbacks = [f(...), g(...)];

As for the purpose of the feature as a whole, although it seems like it could be replaced with function composition as mentioned at the end of the article, and the function composition could be implemented with a utility function instead of dedicated syntax, the advantage of adding these operators is apparently [2] performance (fewer function calls) and facilitating static type-checking.

[1] https://wiki.php.net/rfc/first_class_callable_syntax

[2] https://wiki.php.net/rfc/function-composition#why_in_the_eng...

[mort96]

Thanks, that makes sense!