diff --git a/CHANGELOG b/CHANGELOG --- a/CHANGELOG +++ b/CHANGELOG @@ -1,5 +1,13 @@ +0.12.0 (2024-08-30): + - Switched to using data-fix, which causes several breaking changes. + * The oldest supported GHC is now 8.6.1 (September 2018). + * Several functions exported from "Data.Functor.Fixedpoint" are now deprecated, with error messages indicating the data-fix function to use instead. + * The "Data.Functor.Fixedpoint" module used to have several rewrite rules for fusing various functions (to avoid redundant traversal of data structures); but all of these are no longer active. If this introduces any performance regressions for you, please let the maintainer know. + +0.11.2.3 (2024-08-29): + - Updated version lower-bounds, to fix https://github.com/wrengr/unification-fd/issues/71 0.11.2.2 (2024-08-28): - - Updated version bounds for GHC 9.10, and logict-0.8.1 + - Updated version upper-bounds for GHC 9.10, and logict-0.8.1 0.11.2.1 (2022-08-28): - Updated verion bounds for GHC 9.4 0.11.2 (2022-05-25): diff --git a/src/Control/Unification/Types.hs b/src/Control/Unification/Types.hs --- a/src/Control/Unification/Types.hs +++ b/src/Control/Unification/Types.hs @@ -53,7 +53,7 @@ import Prelude hiding (mapM, sequence, foldr, foldr1, foldl, foldl1) import Data.Word (Word8) -import Data.Functor.Fixedpoint (Fix(..), unFix) +import Data.Fix (Fix(..)) #if __GLASGOW_HASKELL__ < 804 import Data.Monoid ((<>)) #endif diff --git a/src/Data/Functor/Fixedpoint.hs b/src/Data/Functor/Fixedpoint.hs --- a/src/Data/Functor/Fixedpoint.hs +++ b/src/Data/Functor/Fixedpoint.hs @@ -1,45 +1,36 @@ --- For the Show (Fix f) instance -{-# LANGUAGE UndecidableInstances #-} --- For 'build' and 'hmap' +-- For 'build', 'hmap', and 'hmapM' {-# LANGUAGE Rank2Types #-} -{-# LANGUAGE CPP #-} --- Unfortunately GHC < 6.10 needs -fglasgow-exts in order to actually --- parse RULES (see -ddump-rules); the -frewrite-rules flag only --- enables the application of rules, instead of doing what we want. --- Apparently this is fixed in 6.10. In newer GHC (e.g., 7.6.1) the --- -frewrite-rules flag is deprecated in favor of -fenable-rewrite-rules. --- It's unclear whether we can use CPP to switch between -fglasgow-exts --- -frewrite-rules and -fenable-rewrite-rules based on the GHC --- version... --- --- http://hackage.haskell.org/trac/ghc/ticket/2213 --- http://www.mail-archive.com/glasgow-haskell-users@haskell.org/msg14313.html -{-# OPTIONS_GHC -O2 -fenable-rewrite-rules #-} - --- NOTE #1: on GHC >= 7.8 we need to eta expand rules to avoid a --- warning about the fact that the rule may never fire because (.) --- might inline first. On GHC >= 8.0 it's even more aggressive about --- these warnings. - {-# OPTIONS_GHC -Wall -fwarn-tabs #-} ---------------------------------------------------------------- --- 2021.12.31 +-- 2024-11-20 -- | -- Module : Data.Functor.Fixedpoint --- Copyright : Copyright (c) 2007--2021 wren gayle romano +-- Copyright : Copyright (c) 2007--2024 wren gayle romano -- License : BSD -- Maintainer : wren@cpan.org --- Stability : provisional +-- Stability : deprecated since unification-fd-0.12.0 -- Portability : semi-portable (Rank2Types) -- --- This module provides a fixed point operator on functor types. --- For Haskell the least and greatest fixed points coincide, so we --- needn't distinguish them. This abstract nonsense is helpful in --- conjunction with other category theoretic tricks like Swierstra's --- functor coproducts (not provided by this package). For more on --- the utility of two-level recursive types, see: +-- This module provides a backwards compatibility shim for users +-- of older versions of @unification-fd@, before we switched over +-- to using @data-fix@. New users should prefer calling @data-fix@ +-- functions directly, whenever possible. If you use any of the +-- functions that aren't deprecated ('hoistFixM', 'ymap', 'ymapM', +-- 'ycata', 'ycataM', 'build'), please let the maintainer know, +-- so she can focus on getting those incorporated into @data-fix@. +-- Returning users should beware that this module used to provide +-- rewrite rules for fusing redundant traversals of data structures +-- (which @data-fix@ does not). If you notice version >=0.12.0 +-- introducing any performance loss compared to earlier versions, +-- please let the maintainer know, so she can focus on getting those +-- incorporated into @data-fix@. -- +-- This abstract nonsense is helpful in conjunction with other +-- category theoretic tricks like Swierstra's functor coproducts +-- (not provided by this package). For more on the utility of +-- two-level recursive types, see: +-- -- * Tim Sheard (2001) /Generic Unification via Two-Level Types/ -- /and Parameterized Modules/, Functional Pearl, ICFP. -- @@ -54,9 +45,9 @@ module Data.Functor.Fixedpoint ( -- * Fixed point operator for functors - Fix(..), unFix + Data.Fix.Fix(..) -- * Maps - , hmap, hmapM + , hmap, hmapM, hoistFixM' , ymap, ymapM -- * Builders , build @@ -72,138 +63,53 @@ import Prelude hiding (mapM, sequence) import Control.Monad hiding (mapM, sequence) import Data.Traversable +import Data.Fix (Fix()) +import qualified Data.Fix ---------------------------------------------------------------- ---------------------------------------------------------------- --- | @Fix f@ is a fix point of the 'Functor' @f@. Note that in --- Haskell the least and greatest fixed points coincide, so we don't --- need to distinguish between @Mu f@ and @Nu f@. This type used --- to be called @Y@, hence the naming convention for all the @yfoo@ --- functions. --- --- This type lets us invoke category theory to get recursive types --- and operations over them without the type checker complaining --- about infinite types. The 'Show' instance doesn't print the --- constructors, for legibility. -newtype Fix f = Fix (f (Fix f)) - --- Must not phrase this as a record field, or else we can't give --- it an inline pragma, which in turn means some of the rules will --- complain about it being inlined too soon. -unFix :: Fix f -> f (Fix f) -unFix (Fix f) = f -{-# INLINE [0] unFix #-} - --- This requires UndecidableInstances because the context is larger --- than the head and so GHC can't guarantee that the instance safely --- terminates. It is in fact safe, however. -instance (Show (f (Fix f))) => Show (Fix f) where - showsPrec p (Fix f) = showsPrec p f - --- (2021.12.31): removed the definition of @(/=)@ for: --- -instance (Eq (f (Fix f))) => Eq (Fix f) where - Fix x == Fix y = x == y --- BUGFIX: Inlining causes a code explosion on GHC 8.0.1 and 8.0.2, but --- will be fixed in 8.0.3. -#if __GLASGOW_HASKELL__ == 800 - {-# NOINLINE (==) #-} -#endif - -instance (Ord (f (Fix f))) => Ord (Fix f) where - Fix x `compare` Fix y = x `compare` y - Fix x > Fix y = x > y - Fix x >= Fix y = x >= y - Fix x <= Fix y = x <= y - Fix x < Fix y = x < y - Fix x `max` Fix y = Fix (max x y) - Fix x `min` Fix y = Fix (min x y) --- BUGFIX: Inlining causes a code explosion on GHC 8.0.1 and 8.0.2, but --- will be fixed in 8.0.3. -#if __GLASGOW_HASKELL__ == 800 - {-# NOINLINE compare #-} - {-# NOINLINE (>) #-} - {-# NOINLINE (>=) #-} - {-# NOINLINE (<=) #-} - {-# NOINLINE (<) #-} - {-# NOINLINE max #-} - {-# NOINLINE min #-} -#endif - ----------------------------------------------------------------- - -- | A higher-order map taking a natural transformation @(f -> g)@ -- and lifting it to operate on @Fix@. +-- +-- NOTE: The implementation of @hmap@ prior to version 0.12 was +-- based on 'ana', and therefore most closely matches the behavior +-- of 'Data.Fix.hoistFix''. However, this definition is extensionally +-- equivalent to an implementation using 'cata' (and therefore most +-- closely matches the behavior of 'Data.Fix.hoistFix') instead. hmap :: (Functor f, Functor g) => (forall a. f a -> g a) -> Fix f -> Fix g -{-# INLINE [0] hmap #-} -hmap eps = ana (eps . unFix) - -- == cata (Fix . eps) -- But the anamorphism is a better producer. - -{-# RULES --- Alas, rule won't fire because 'id' may inline too early. --- "hmap id" --- hmap id = id - --- cf., NOTE #1 -"hmap-compose" - forall (eps :: forall a. g a -> h a) (eta :: forall a. f a -> g a) x. - hmap eps (hmap eta x) = hmap (eps . eta) x - #-} - +hmap = Data.Fix.hoistFix' +{-# DEPRECATED hmap "Use Data.Fix.hoistFix'" #-} -- | A monadic variant of 'hmap'. hmapM :: (Functor f, Traversable g, Monad m) => (forall a. f a -> m (g a)) -> Fix f -> m (Fix g) -{-# INLINE [0] hmapM #-} -hmapM eps = anaM (eps . unFix) - -{-# RULES --- Alas, rule won't fire because 'return' may inline too early. --- "hmapM return" --- hmapM return = return - --- "hmapM-compose" --- forall eps eta. --- hmap eps <=< hmap eta = hmapM (eps <=< eta) - #-} +hmapM = hoistFixM' +{-# DEPRECATED hmapM "Use hoistFixM'" #-} +-- | A monadic variant of 'Data.Fix.hoistFix''. +-- +-- NOTE: The implementation of @hmapM@ prior to version 0.12 was +-- based on 'anaM', and therefore most closely matches the behavior +-- of 'Data.Fix.unfoldFixM'. However, there is another function +-- of the same type which is instead implemented via 'cataM', +-- which has different semantics for many monads. +hoistFixM' + :: (Functor f, Traversable g, Monad m) + => (forall a. f a -> m (g a)) -> Fix f -> m (Fix g) +hoistFixM' eps = Data.Fix.unfoldFixM (eps . Data.Fix.unFix) -- | A version of 'fmap' for endomorphisms on the fixed point. That -- is, this maps the function over the first layer of recursive -- structure. ymap :: (Functor f) => (Fix f -> Fix f) -> Fix f -> Fix f -{-# INLINE [0] ymap #-} -ymap f = Fix . fmap f . unFix - -{-# RULES --- Alas, rule won't fire because 'id' may inline too early. --- "ymap id" --- ymap id = id - --- cf., NOTE #1 -"ymap-compose" - forall f g x. - ymap f (ymap g x) = ymap (f . g) x - #-} - +ymap f = Data.Fix.Fix . fmap f . Data.Fix.unFix -- | A monadic variant of 'ymap'. ymapM :: (Traversable f, Monad m) => (Fix f -> m (Fix f)) -> Fix f -> m (Fix f) -{-# INLINE [0] ymapM #-} -ymapM f = liftM Fix . mapM f . unFix - -{-# RULES --- Alas, rule won't fire because 'return' may inline too early. --- "ymapM id" --- ymapM return = return - --- "ymapM-compose" --- forall f g. --- ymapM f <=< ymapM g = ymapM (f <=< g) - #-} +ymapM f = liftM Data.Fix.Fix . mapM f . Data.Fix.unFix ---------------------------------------------------------------- @@ -212,44 +118,15 @@ -- | Take a Church encoding of a fixed point into the data -- representation of the fixed point. build :: (Functor f) => (forall r. (f r -> r) -> r) -> Fix f -{-# INLINE [0] build #-} -build g = g Fix - --- N.B., the signature is required on @g@ in order to be Rank-2. --- The signature is required on @phi@ in order to bring @f@ into --- scope. Otherwise we'd need -XScopedTypeVariables. -{-# RULES -"build/cata" [1] - forall (phi :: f a -> a) (g :: forall r. (f r -> r) -> r). - cata phi (build g) = g phi - #-} +build g = g Data.Fix.Fix ---------------------------------------------------------------- -- | A pure catamorphism over the least fixed point of a functor. -- This function applies the @f@-algebra from the bottom up over -- @Fix f@ to create some residual value. cata :: (Functor f) => (f a -> a) -> (Fix f -> a) -{-# INLINE [0] cata #-} -cata phi = self - where - self = phi . fmap self . unFix - -{-# RULES -"cata-refl" - cata Fix = id - --- cf., NOTE #1 -"cata-compose" - forall (eps :: forall a. f a -> g a) phi x. - cata phi (cata (\y -> Fix (eps y)) x) = cata (phi . eps) x - #-} - --- We can't really use this one because of the implication constraint -{- RULES -"cata-fusion" - forall f phi. (f . phi) == (phi . fmap f) ==> - f . cata phi = cata phi --} +cata = Data.Fix.foldFix +{-# DEPRECATED cata "Use Data.Fix.foldFix" #-} -- | A catamorphism for monadic @f@-algebras. Alas, this isn't wholly @@ -258,18 +135,8 @@ -- -- N.B., this orders the side effects from the bottom up. cataM :: (Traversable f, Monad m) => (f a -> m a) -> (Fix f -> m a) -{-# INLINE [0] cataM #-} -cataM phiM = self - where - self = phiM <=< (mapM self . unFix) - --- TODO: other rules for cataM -{-# RULES --- Alas, rule won't fire because 'return' may inline too early. --- "cataM-refl" --- cataM (return . Fix) = return - #-} - +cataM = Data.Fix.foldFixM +{-# DEPRECATED cataM "Use Data.Fix.foldFixM" #-} -- TODO: remove this, or add similar versions for ana* and hylo*? -- | A variant of 'cata' which restricts the return type to being @@ -279,16 +146,14 @@ -- If you don't like either @fmap@ or @cata@, then maybe this is -- what you were thinking? ycata :: (Functor f) => (Fix f -> Fix f) -> Fix f -> Fix f -{-# INLINE ycata #-} -ycata f = cata (f . Fix) +ycata f = Data.Fix.foldFix (f . Data.Fix.Fix) -- TODO: remove this, or add similar versions for ana* and hylo*? -- | Monadic variant of 'ycata'. ycataM :: (Traversable f, Monad m) => (Fix f -> m (Fix f)) -> Fix f -> m (Fix f) -{-# INLINE ycataM #-} -ycataM f = cataM (f . Fix) +ycataM f = Data.Fix.foldFixM (f . Data.Fix.Fix) ---------------------------------------------------------------- @@ -296,31 +161,8 @@ -- functor. This function applies an @f@-coalgebra from the top -- down to expand a seed into a @Fix f@. ana :: (Functor f) => (a -> f a) -> (a -> Fix f) -{-# INLINE [0] ana #-} -ana psi = self - where - self = Fix . fmap self . psi - - -{-# RULES -"ana-refl" - ana unFix = id - --- BUG: I think I dualized this right... --- cf., NOTE #1 -"ana-compose" - forall (eps :: forall a. f a -> g a) psi x. - ana (\y -> eps (unFix y)) (ana psi x) = ana (eps . psi) x - #-} - --- We can't really use this because of the implication constraint -{- RULES --- BUG: I think I dualized this right... -"ana-fusion" - forall f psi. (psi . f) == (fmap f . psi) ==> - ana psi . f = ana psi --} - +ana = Data.Fix.unfoldFix +{-# DEPRECATED ana "Use Data.Fix.unfoldFix" #-} -- | An anamorphism for monadic @f@-coalgebras. Alas, this isn't -- wholly generic to @Functor@ since it requires distribution of @@ -328,38 +170,21 @@ -- -- N.B., this orders the side effects from the top down. anaM :: (Traversable f, Monad m) => (a -> m (f a)) -> (a -> m (Fix f)) -{-# INLINE anaM #-} -anaM psiM = self - where - self = (liftM Fix . mapM self) <=< psiM +anaM = Data.Fix.unfoldFixM +{-# DEPRECATED anaM "Use Data.Fix.unfoldFixM" #-} ---------------------------------------------------------------- --- Is this even worth mentioning? We can amortize the construction --- of @Fix f@ (which we'd do anyways because of laziness), but we --- can't fuse the @f@ away unless we inline all of @psi@, @fmap@, --- and @phi@ at the use sites. Will inlining this definition be --- sufficient to do that? - -- | @hylo phi psi == cata phi . ana psi@ hylo :: (Functor f) => (f b -> b) -> (a -> f a) -> (a -> b) -{-# INLINE hylo #-} -hylo phi psi = self - where - self = phi . fmap self . psi - --- TODO: rules for hylo? - +hylo = Data.Fix.refold +{-# DEPRECATED hylo "Use Data.Fix.refold" #-} -- | @hyloM phiM psiM == cataM phiM <=< anaM psiM@ hyloM :: (Traversable f, Monad m) => (f b -> m b) -> (a -> m (f a)) -> (a -> m b) -{-# INLINE hyloM #-} -hyloM phiM psiM = self - where - self = phiM <=< mapM self <=< psiM - --- TODO: rules for hyloM? +hyloM = Data.Fix.refoldM +{-# DEPRECATED hyloM "Use Data.Fix.refoldM" #-} ---------------------------------------------------------------- ----------------------------------------------------------- fin. diff --git a/unification-fd.cabal b/unification-fd.cabal --- a/unification-fd.cabal +++ b/unification-fd.cabal @@ -6,11 +6,11 @@ -- ---------------------------------------------------------------- --- wren gayle romano ~ 2024-08-28 +-- wren gayle romano ~ 2024-08-30 ---------------------------------------------------------------- Name: unification-fd -Version: 0.11.2.2 +Version: 0.12.0 Build-Type: Simple Stability: experimental Homepage: https://wrengr.org/software/hackage.html @@ -32,15 +32,9 @@ Extra-source-files: AUTHORS, README.md, CHANGELOG --- This should work as far back as GHC 7.4.2, but we don't verify that by CI. --- (No longer compiles with GHC-6.12.1 since "Data.Monoid" does not --- export @(<>)@ in "Control.Unification.Types"; and adding the --- backwards compatibility isn't worth adding CPP noise...) +-- Because of data-fix, we can no longer support GHC older than 8.6.1 -- Tested-With: - GHC ==8.0.2, - GHC ==8.2.2, - GHC ==8.4.4, GHC ==8.6.5, GHC ==8.8.4, GHC ==8.10.3, @@ -72,23 +66,30 @@ , Control.Unification.Ranked.STVar , Control.Unification.Ranked.IntVar - -- N.B., logict 0.7.1 introduced breakage, but that - -- should be resolved now. Cf., - -- - -- - Build-Depends: logict >= 0.4 && < 0.8.2 - -- N.B., Tasty requires base>=4.5.0.0; which - -- means we aren't CI testing anything older than - -- that anymore, so we might as well just require - -- that version so we can remove the ancient base4 - -- and splitBase build flags. - , base >= 4.5 && < 4.21 - , containers - -- Require mtl-2 instead of monads-fd; because - -- otherwise we get a clash mixing logict with - -- StateT. And we want stuff from monads-fd, so - -- we can't just fail over to the older mtl. - , mtl >= 2.0 + -- TODO: Although most versions of mtl don't really care much + -- about the version of base, the latest version (mtl-2.3.1) is + -- exceptional in that they explicitly exclude base>=4.15&&<4.16. + -- We should look into why, just in case that affects us too. + -- + -- To keep the core libs matching the Tested-With bounds above, see: + -- + Build-Depends: base >= 4.12 && < 4.21 + , containers >= 0.6.0 && < 0.8 + -- Require mtl-2 instead of monads-fd; because + -- otherwise we get a clash mixing logict with + -- StateT. And we want stuff from monads-fd, so + -- we can't just fail over to the older mtl. + -- + -- NOTE: ghc>=8.4.1 ships with mtl>=2.2.2, so that's where + -- our lower bound comes from (but any mtl>=2.0 should work). + , mtl >= 2.2.2 && < 2.4 + -- NOTE: logict-0.7.1 introduced breakage, but that + -- should be resolved now. Cf., + -- + -- + , logict >= 0.4 && < 0.8.2 + -- FIXME: What all changed between 0.3.2 and 0.3.4? And why does my current GHC not want to try 0.3.4? + , data-fix >= 0.3.2 && < 0.4 ---------------------------------------------------------------- ----------------------------------------------------------- fin.