Clj-rpe is a Clojure library that implements Regular Path Expressions (RPEs) on Clojure data structures and arbitrary Java objects. It enables you to retrieve the ordered set of objects reachable from a given start object (or set of start objects) by traversing a path conforming to a regular path description.

A regular path description is a declarative means to specify allowed paths in some object structure in terms of keys in a map or fields/methods in classes. Those can be composed using regular operators such as sequence, option, alternative, and iterations.