MIT licensed by Li-yao Xia
Maintained by [email protected]
This version can be pinned in stack with:boltzmann-samplers-0.1.1.0@sha256:d4a5ee732777aec9355e20720dec3d95aea3987763f36cb9b5673fe78ba74228,2246

Boltzmann samplers Hackage Build Status

Boltzmann.Data

Define sized random generators for Data.Data generic types.

    {-# LANGUAGE DeriveDataTypeable #-}

    import Data.Data
    import Test.QuickCheck
    import Boltzmann.Data

    data Term = Lambda Int Term | App Term Term | Var Int
      deriving (Show, Data)

    instance Arbitrary Term where
      arbitrary = sized $ generatorPWith [positiveInts]

    positiveInts :: Alias Gen
    positiveInts =
      alias $ \() -> fmap getPositive arbitrary :: Gen Int

    main = sample (arbitrary :: Gen Term)
  • Objects of the same size (number of constructors) occur with the same probability (see Duchon et al., references below).
  • Implements rejection sampling and pointing.
  • Works with QuickCheck and MonadRandom, but also similar user-defined monads for randomness (just implement MonadRandomLike).
  • Can be tweaked somewhat with user defined generators.

Boltzmann.Species

An experimental interface to obtain Boltzmann samplers from an applicative specification of a combinatorial system.

No documentation (yet).

References

Changes

0.1.1.0

  • Added Semigroup Nat instance, for compatibility with GHC 8.4