diff --git a/CHANGELOG.md b/CHANGELOG.md --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -1,5 +1,10 @@ # Revision history for monoidal-functors -## 0.1.0.0 -- YYYY-mm-dd +## 0.1.1 -- 2021-12-13 -* First version. Released on an unsuspecting world. +* Removes redundant `Iso` types. +* Some intitial attempts at documentation. + +## 0.1.0.0 -- 2021-04-19 + +* First version. diff --git a/monoidal-functors.cabal b/monoidal-functors.cabal --- a/monoidal-functors.cabal +++ b/monoidal-functors.cabal @@ -1,30 +1,33 @@ cabal-version: 2.4 name: monoidal-functors category: Control, Categories -version: 0.1.0.0 +version: 0.1.1.0 license: MIT license-file: LICENSE author: Solomon Bothwell & Asad Saeeduddin maintainer: ssbothwell@gmail.com stability: experimental -homepage: http://github.com/ssbothwell/monoidal-functors +synopsis: Monoidal Functors Library +homepage: http://github.com/solomon-b/monoidal-functors build-type: Simple extra-source-files: CHANGELOG.md description: A typeclass hierarchy for monoidal functors. +source-repository head + type: git + location: https://github.com/solomon-b/monoidal-functors + library build-depends: - base >= 4.12 && < 5 - -- , base-orphans ^>= 0.8.4 - , bifunctors - , comonad - , contravariant - , profunctors - , semigroupoids - , tagged - , these - -- , transformers ^>= 0.5 + base >= 4.12 && < 5, + bifunctors >= 5.5.11 && < 5.6, + comonad >= 5.0.8 && < 5.1, + tagged >= 0.8.6 && < 0.9, + contravariant >= 1.5.5 && < 1.6, + profunctors >= 5.6.2 && < 5.7, + semigroupoids >= 5.3.6 && < 5.4, + these >= 1.1.1 && < 1.2, exposed-modules: Control.Category.Tensor @@ -38,7 +41,7 @@ Data.Trifunctor.Module Data.Trifunctor.Monoidal - ghc-options: -Wall -O2 -Wno-trustworthy-safe -Wno-star-is-type + ghc-options: -Wall -Wno-trustworthy-safe -Wno-star-is-type if impl(ghc >= 9.0) -- these flags may abort compilation with GHC-8.10 @@ -49,22 +52,23 @@ default-language: Haskell2010 - default-extensions: ConstraintKinds - DeriveFunctor - DerivingVia - FunctionalDependencies - FlexibleInstances - FlexibleContexts - GeneralizedNewtypeDeriving - InstanceSigs - KindSignatures - LambdaCase - MultiParamTypeClasses - NoImplicitPrelude - QuantifiedConstraints - RankNTypes - ScopedTypeVariables - StandaloneDeriving - TypeApplications - TypeOperators - UndecidableInstances + default-extensions: + ConstraintKinds + DeriveFunctor + DerivingVia + FunctionalDependencies + FlexibleInstances + FlexibleContexts + GeneralizedNewtypeDeriving + InstanceSigs + KindSignatures + LambdaCase + MultiParamTypeClasses + NoImplicitPrelude + QuantifiedConstraints + RankNTypes + ScopedTypeVariables + StandaloneDeriving + TypeApplications + TypeOperators + UndecidableInstances diff --git a/src/Data/Bifunctor/BiInvariant.hs b/src/Data/Bifunctor/BiInvariant.hs --- a/src/Data/Bifunctor/BiInvariant.hs +++ b/src/Data/Bifunctor/BiInvariant.hs @@ -2,6 +2,7 @@ import Prelude import Control.Arrow +import Control.Category.Tensor import Control.Comonad import Data.Bifunctor import Data.Bifunctor.Biap @@ -37,8 +38,7 @@ biinvmap :: (a' -> a) -> (a -> a') -> (b' -> b) -> (b -> b') -> p a b -> p a' b' -- BiInvariant witnesses an Isomorphism -data Iso a b = Iso (a -> b) (b -> a) -biinvIso :: BiInvariant p => Iso a a' -> Iso b b' -> Iso (p a b) (p a' b') +biinvIso :: BiInvariant p => Iso (->) a a' -> Iso (->) b b' -> Iso (->) (p a b) (p a' b') biinvIso (Iso f f') (Iso g g') = Iso (biinvmap f' f g' g) (biinvmap f f' g g') newtype FromProfunctor p a b = FromProfunctor { runPro :: p a b} diff --git a/src/Data/Functor/Invariant.hs b/src/Data/Functor/Invariant.hs --- a/src/Data/Functor/Invariant.hs +++ b/src/Data/Functor/Invariant.hs @@ -2,6 +2,7 @@ import Prelude import Control.Applicative (ZipList) +import Control.Category.Tensor import Data.Functor.Contravariant import Data.Functor.Compose import Data.Functor.Identity @@ -12,10 +13,7 @@ class Invariant f where invmap :: (a -> a') -> (a' -> a) -> f a -> f a' --- Invariant witnesses an Isomorphism -data Iso a b = Iso (a -> b) (b -> a) - -invIso :: Invariant f => Iso a a' -> Iso (f a) (f a') +invIso :: Invariant f => Iso (->) a a' -> Iso (->) (f a) (f a') invIso (Iso f g) = Iso (invmap f g) (invmap g f) newtype FromFunctor f a = FromFunctor { runBi :: f a } diff --git a/src/Data/Functor/Monoidal.hs b/src/Data/Functor/Monoidal.hs --- a/src/Data/Functor/Monoidal.hs +++ b/src/Data/Functor/Monoidal.hs @@ -5,17 +5,38 @@ import Control.Category.Tensor import Data.Void -class (Associative t1 cat, Associative t0 cat) => Semigroupal cat t1 t0 f where - combine :: (f x `t0` f x') `cat` f (x `t1` x') - -class Unital cat i1 i0 f where - introduce :: i0 `cat` f i1 - +-- | A is a Functor between two Monoidal Categories +-- which preserves the monoidal structure. Eg., a homomorphism of +-- monoidal categories. +-- +-- = Laws +-- Associativity: +-- combine (combine fx fy) fz ⟶ combine fx (combine fy fz) +-- ↓ ↓ +-- f (x `t1` y) `t1` fz combine fx (f (y `t1` z)) +-- ↓ ↓ +-- f ((x `t1` y) `t1` z) ⟶ (f x `t1` (y `t1` z)) +-- +-- Left Unitality: +-- empty `t1` f x ⟶ f empty `t1` f x +-- ↓ ↓ +-- f x ← f (empty `t0` x) +-- +-- Right Unitality: +-- f x `t1` empty ⟶ f x `t1` f empty +-- ↓ ↓ +-- f x ← f (x `t0` empty) class ( Tensor t1 i1 cat , Tensor t0 i0 cat , Semigroupal cat t1 t0 f , Unital cat i1 i0 f ) => Monoidal cat t1 i1 t0 i0 f + +class (Associative t1 cat, Associative t0 cat) => Semigroupal cat t1 t0 f where + combine :: (f x `t0` f x') `cat` f (x `t1` x') + +class Unital cat i1 i0 f where + introduce :: i0 `cat` f i1 -- TODO: Should we create an Apply class? instance Applicative f => Semigroupal (->) (,) (,) f where