data-fix

Fixpoint data types https://github.com/spell-music/data-fix

This package is not currently in any snapshots. If you're interested in using it, we recommend adding it to Stackage Nightly. Doing so will make builds more reliable, and allow stackage.org to host generated Haddocks.

BSD-3-Clause licensed by Anton Kholomiov, Edward Kmett, Oleg Grenrus
Maintained by <anton.kholomiov@gmail.com>

Fixpoint types and recursion schemes. If you define your AST as fixpoint type, you get fold and unfold operations for free.

Thanks for contribution to: Matej Kollar, Herbert Valerio Riedel

Changes

0.3.0

  • Rename cata, ana and hylo into foldFix, unfoldFix and `refold. Old names are now deprecated, and will be eventually removed. Similarly, rename monadic variants.
  • Add hoistFix and hoistFix' function.
  • Add Hashable and NFData instance. Latter is available only with deepseq >=1.4.3.0, which provides NFData1 type-class
  • Change Eq, Ord, Show and Read instances to use Eq1, Ord1, Show1 and Read1 instances of a base functor.
  • Add least and greatest fixed point types, Mu and Nu.
  • Drop requirement for Applicative m in monadic combinators, Monad m is enough.
  • Remove ~> alias for refold (hylo).
  • Extend the GHC support window. There is nothing magical in this package.
  • Mark Data.Fix as Trustworthy (Safe Haskell)
  • Make refold (and refoldM) more efficient. This results in different effect ordering for refoldM.