haskell@gentoo.org Gentoo Haskell HaRP, or Haskell Regular Patterns, is a Haskell extension that extends the normal pattern matching facility with the power of regular expressions. This expressive power is highly useful in a wide range of areas, including text parsing and XML processing. Regular expression patterns in HaRP work over ordinary Haskell lists ([]) of arbitrary type. HaRP is implemented as a pre-processor to ordinary Haskell. seereason/harp