A language for specifying recursive traversals of object structures

We present a domain-specific language for specifying recursive traversals of object structures, for use with the visitor pattern. Traversals are traditionally specified as iterations, forcing the programmer to adopt an imperative style, or are hard-coded into the program or visitor. Our proposal allows a number of problems best approached by recursive means to be tackled with the visitor pattern, while retaining the benefits of a separate traversal specification.