Metaprogramming consists of programming a program. In other words, you lay out code that the programming system executes to generate new code that implements the functionality you really want.

A look at what to watch out for in metaprogramming when it comes to speed, and: how ParseTree can be used to implement LISP/Scheme-style Macros in Ruby and avoid some of the issues of Open Classes.

Metaprogramming allows you to automate error-prone or repetitive programming tasks. You can use it to pre-generate data tables, to generate boilerplate code automatically that can't be abstracted into ...

As I’ve mentioned, metaprogramming in Groovy is a huge topic and well worth exploring. Here I’ve covered just enough to get you started with writing internal DSLs in Groovy.