diff --git a/ffunctor.cabal b/ffunctor.cabal --- a/ffunctor.cabal +++ b/ffunctor.cabal @@ -1,66 +1,76 @@ -cabal-version: 2.2 -name: ffunctor -version: 1.2.0 -synopsis: FFunctor typeclass -license: BSD-3-Clause -license-file: LICENSE -author: Sam Halliday -maintainer: Sam Halliday -copyright: 2019 Sam Halliday -bug-reports: https://gitlab.com/fommil/ffunctor/merge_requests -tested-with: GHC ^>= 8.4.4 || ^>= 8.6.3 -category: Constraints +cabal-version: 2.2 +name: ffunctor +version: 1.2.1 +synopsis: FFunctor typeclass +license: BSD-3-Clause +license-file: LICENSE +author: Sam Halliday +maintainer: Sam Halliday +copyright: 2019 Sam Halliday +bug-reports: https://gitlab.com/fommil/ffunctor/merge_requests +tested-with: GHC ^>=8.4.4 || ^>=8.6.5 +category: Constraints description: Micro library with a Higher Kinded Functor in the spirit of HFunctor, MFunctor and MonadTrans (which all have different kindedness). . - Useful to map over the type parameter in a record of - functions, e.g. https://www.benjamin.pizza/posts/2017-12-15-functor-functors.html - and https://discourse.haskell.org/t/local-capabilities-with-mtl/231 - and https://discourse.haskell.org/t/some-limits-of-mtl-with-records-of-functions/576 + Useful to map over the type parameter in a record of functions + . + * https://www.benjamin.pizza/posts/2017-12-15-functor-functors.html + * https://discourse.haskell.org/t/local-capabilities-with-mtl/231 + * https://discourse.haskell.org/t/some-limits-of-mtl-with-records-of-functions/576 + * https://discourse.haskell.org/t/records-of-functions-and-implicit-parameters/747 source-repository head - type: git + type: git location: https://gitlab.com/fommil/ffunctor flag transformers description: Compile with transformers utilities - manual: True - default: True + manual: True + default: True common deps - build-depends: , base ^>= 4.11.1.0 || ^>= 4.12.0.0 - ghc-options: -Wall - -Werror=missing-home-modules - default-language: Haskell2010 + build-depends: base >=4.11 && <5 + ghc-options: -Wall -Werror=missing-home-modules + default-language: Haskell2010 library - import: deps - hs-source-dirs: library - exposed-modules: Data.FFunctor + import: deps + hs-source-dirs: library + + -- cabal-fmt: expand library + exposed-modules: Data.FFunctor + if flag(transformers) - build-depends: , transformers - cpp-options: -DHAVE_TRANSFORMERS + build-depends: transformers + cpp-options: -DHAVE_TRANSFORMERS -test-suite tests +test-suite tests import: deps hs-source-dirs: test type: exitcode-stdio-1.0 main-is: Driver.hs - other-modules: Data.FFunctor.ServantTest - , Data.FFunctor.TracingTest - build-depends: , ffunctor - , aeson ^>= 1.4.1.0 - , exceptions ^>= 0.10.1 - , mtl ^>= 2.2.2 - , generic-lens ^>= 1.1.0.0 - , http-client ^>= 0.5.12 - , servant ^>= 0.14.1 - , servant-client ^>= 0.14 - , tasty ^>= 1.2.1 - , tasty-hspec ^>= 1.1.5 - , tasty-quickcheck ^>= 0.10 - , time ^>= 1.8.0.2 - , universum ^>= 1.5.0 - build-tool-depends: tasty-discover:tasty-discover ^>= 4.2.1 - ghc-options: -threaded + + -- cabal-fmt: expand test -Driver + other-modules: + Data.FFunctor.ServantTest + Data.FFunctor.TracingTest + + build-depends: + , aeson ^>=1.4.1.0 + , exceptions ^>=0.10.1 + , ffunctor + , generic-lens ^>=1.1.0.0 + , http-client ^>=0.5.12 + , mtl ^>=2.2.2 + , servant ^>=0.14.1 + , servant-client ^>=0.14 + , tasty ^>=1.2.1 + , tasty-hspec ^>=1.1.5 + , tasty-quickcheck ^>=0.10 + , time ^>=1.8.0.2 + , universum ^>=1.5.0 + + build-tool-depends: tasty-discover:tasty-discover ^>=4.2.1 + ghc-options: -threaded diff --git a/library/Data/FFunctor.hs b/library/Data/FFunctor.hs --- a/library/Data/FFunctor.hs +++ b/library/Data/FFunctor.hs @@ -1,9 +1,10 @@ {-# LANGUAGE CPP #-} -{-# LANGUAGE KindSignatures #-} -{-# LANGUAGE Rank2Types #-} {-# LANGUAGE DefaultSignatures #-} {-# LANGUAGE EmptyCase #-} {-# LANGUAGE FlexibleContexts #-} +{-# LANGUAGE KindSignatures #-} +{-# LANGUAGE Rank2Types #-} +{-# LANGUAGE TypeOperators #-} -- | Functor of Functors module Data.FFunctor where @@ -12,26 +13,30 @@ import Control.Monad.Trans.Class (MonadTrans, lift) #endif import Control.Monad.IO.Class (MonadIO, liftIO) -import qualified GHC.Generics as Generics +import Data.Coerce import Data.Functor.Compose +import Data.Functor.Const import Data.Functor.Product import Data.Functor.Sum -import Data.Functor.Const -import Data.Coerce +import qualified GHC.Generics as Generics +-- | A Functor over Functors (aka Higher Kinded Functor) class FFunctor (f :: (* -> *) -> *) where + -- | Applies a natural transformation to a higher kinded type ffmap :: (Functor m, Functor n) => (forall a . (m a -> n a)) -> f m -> f n default ffmap :: (Generics.Generic1 f, FFunctor (Generics.Rep1 f), Functor m, Functor n) => (forall a . (m a -> n a)) -> f m -> f n ffmap f = Generics.to1 . ffmap f . Generics.from1 {-# INLINE ffmap #-} --- | Lifts an IO impl of a record of functions into a more general MonadIO impl +-- | Lifts an IO implementation of a higher kinded type (e.g. record of functions) into a MonadIO +-- +-- e.g. `luftIO logger` lifts a `Logger IO` into a `Logger m` luftIO :: FFunctor f => MonadIO m => f IO -> f m luftIO = ffmap liftIO #ifdef HAVE_TRANSFORMERS --- | Lifts a record of functions (that has an FFunctor) into a monad transformer. +-- | Lifts a higher kinded type (e.g. record of functions) into a monad transformer. -- -- e.g. `luft logger` lifts a `Logger m` into a `Logger (ReaderT m Foo)` luft :: FFunctor f => Monad m => MonadTrans t => Functor (t m) => f m -> f (t m)