Anonymous functions in PHP can be quite verbose, even when they only perform a simple operation. Partly this is due to a large amount of syntactic boilerplate, and party due to the need to manually import used variables. This makes code using simple closures hard to read and understand. This RFC proposes a more concise syntax for this pattern. ... Short closures are critically overdue, and at some point we'll have to make a compromise here, rather than shelving the topic for another few years.
Let's hope this one gets accepted!