It actually optimizes the pattern-matching, and has a complete and well-documented API including an extension mechanism.
optima is the recommended pattern-matching library. It notably supersedes cl-pattern, cl-match, fare-matcher, arnesi's pattern-matching fragment, pcond, and more.
The library trivia uses similar patterns for pattern matching. However unlike optima it provides a unified API for extension. When trivia achieves feature parity with optima, it will officially supersede optima.
Homepage: GitHub
obsolete