IBM developerWorks has posted part two of their look at new features included in the upcoming PHP 5.3 release. This part looks specifically at closures and lambda functions.
Follow along in this "What's new in PHP V5.3" series of articles that covers the new and exciting features found in PHP V5.3, which will be released by the end of 2008. Part 1 looks at the changes made to the object-oriented programming and object handling in PHP V5.3. Here in Part 2, we look at closures and lambda functions. They are designed to make programming much easier by allowing you to easily define throwaway functions that can be used in many contexts.
Lambda functions (or as they describe them "throwaway functions") are ones created dynamically as the script runs, possibly as a callback to one of the many PHP functions that allow for one. It removes the need for a call to create_function. Closures let you assign a function to a variable/return value, including variables to use, and call it later.
They also look at closures and objects, using reflection on them and some reasoning on why you should use closures in your future applications.