Helpers.hs

-- |
-- Module      : Control.Monad.Bayes.Helpers
-- Description : Helper functions for working with inference monads
-- Copyright   : (c) Adam Scibior, 2015-2020
-- License     : MIT
-- Maintainer  : leonhard.markert@tweag.io
-- Stability   : experimental
-- Portability : GHC
module Control.Monad.Bayes.Helpers
  ( W,
    hoistW,
    P,
    hoistP,
    S,
    hoistS,
    F,
    hoistF,
    T,
    hoistT,
    hoistWF,
    hoistSP,
    hoistSTP,
  )
where

import Control.Monad.Bayes.Free as Free
import Control.Monad.Bayes.Population as Pop
import Control.Monad.Bayes.Sequential as Seq
import Control.Monad.Bayes.Traced as Tr
import Control.Monad.Bayes.Weighted as Weighted

type W = Weighted

type P = Population

type S = Sequential

type F = FreeSampler

type T = Traced

hoistW :: (forall x. m x -> n x) -> W m a -> W n a
hoistW = Weighted.hoist

hoistP ::
  (Monad m, Monad n) =>
  (forall x. m x -> n x) ->
  P m a ->
  P n a
hoistP = Pop.hoist

hoistS :: (forall x. m x -> m x) -> S m a -> S m a
hoistS = Seq.hoistFirst

hoistF :: (Monad m, Monad n) => (forall x. m x -> n x) -> F m a -> F n a
hoistF = Free.hoist

hoistWF ::
  (Monad m, Monad n) =>
  (forall x. m x -> n x) ->
  W (F m) a ->
  W (F n) a
hoistWF m = hoistW $ hoistF m

hoistSP ::
  Monad m =>
  (forall x. m x -> m x) ->
  S (P m) a ->
  S (P m) a
hoistSP m = hoistS $ hoistP m

hoistSTP ::
  Monad m =>
  (forall x. m x -> m x) ->
  S (T (P m)) a ->
  S (T (P m)) a
hoistSTP m = hoistS $ hoistT $ hoistP m