Researching a bit for my previous post about closures in Python and Ruby I found out that they are coming in PHP 5.3. Here is the RFC. Unfortunately it requires declaring the closed variables with the use keyword and provides a justification for it:

PHP's notion of scope is quite different than the notion of scope other languages define. Combine this with variable variables ($$var) and it becomes clear that automatically detecting which variables from the outer scope are referenced inside are closure is impossible.

functional php

PHP4 has been discontinued. About time.

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