Functional data structures on top of CLOS


Patty is a small library that facilitates working with functional data structures. It consists of a few macros and metaclasses that integrate nicely with CLOS. Code using patty is similar in style to Haskell code using algebraic data types, primitive pattern matching and type classes.

Mailing Lists


The latest release is 1.0.6. Download gzipped tarball.
It depends on closer-mop, moptilities and Alexandria. LIFT and cl-ppcre are only needed to run the test suite (only the patty-test system depends on them).
Alternatively you can install via asdf-install (with the caveat that Alexandria is currently not asdf-installable).

You can get the latest via darcs:

    darcs get



Patty uses the abstract-class and singleton-class definitions from Tim Bradshaw's Lisp hacks.

Project members

Stefan Lang