BSD-3-Clause licensed and maintained by Oleg Grenrus
This version can be pinned in stack with:kleene-0.1@sha256:4d33abcf07b426d16e548dbd55343e88beee1783bbbc85f867376c0a7bed2ace,2409

Kleene algebra

Think: Regular expressions

Implements ideas from Regular-expression derivatives re-examined by Scott Owens, John Reppy and Aaron Turon



  • Drop superclasses from Kleene.
  • Rearrange classes. Introduce CharKleene, FiniteKleene.
  • Add ToLatin1 and ability to match on ByteString.
  • Add Derivate c (DFA c) instance.
  • Add toDot to output DFA to be rendered by graphviz.
  • Add fromRE :: RE c -> ERE c
  • Add nullableProof :: RE c -> Maybe (RE c) which returns non-nullable part of given regular expression.
  • Support/require lattices-2: RE is now a Lattice, M isn’t.