bifunctors-5.6.2/0000755000000000000000000000000007346545000012073 5ustar0000000000000000bifunctors-5.6.2/CHANGELOG.markdown0000644000000000000000000002355007346545000015133 0ustar00000000000000005.6.2 [2024.03.19] ------------------ * Support building with `template-haskell-2.22.*` (GHC 9.10). 5.6.1 [2023.03.13] ------------------ * Provide instances for the `Swap` and `Assoc` type classes from the `assoc` package. (These instances were previously defined in `assoc` itself, but they have been migrated over to `bifunctors` in tandem with the `assoc-1.1` release.) * Only depend on `bifunctor-classes-compat` if building with GHC 8.0. 5.6 [2023.03.12] ---------------- * Drop support for GHC 7.10 and earlier. * Move the `Data.Bifunctor`, `Data.Bifoldable`, and `Data.Bitraversable` compatibility modules to the new `bifunctor-classes-compat` package. For backwards compatibility, the `bifunctors` library re-exports `Data.Bifoldable` and `Data.Bitraversable` modules from `bifunctor-classes-compat` when building with GHC 8.0. If your library depends on `bifunctors` and compiles with pre-8.2 versions of GHC, be warned that it may be possible to construct a build plan involving a pre-`5.6` version of `bifunctors` where: * Some of the `Bifunctor` instances come from `bifunctor-classes-compat`'s compatibility classes, and * Other `Bifunctor` instances come from `bifunctors`'s compatibility classes. These compatibility classes are distinct, so this could lead to build errors under certain conditions. Some possible ways to mitigate this risk include: * Drop support for GHC 8.0 and older in your library. * Require `bifunctors >= 5.6` in your library. * If neither of the options above are viable, then you can temporarily define instances for the old compatibility classes from `bifunctors` like so: ```hs -- For Bifunctor instances import qualified "bifunctor-classes-compat" Data.Bifunctor as BifunctorCompat #if !MIN_VERSION_bifunctors(5,6,0) && !MIN_VERSION_base(4,8,0) import qualified "bifunctors" Data.Bifunctor as Bifunctor #endif instance BifunctorCompat.Bifunctor MyType where ... #if !MIN_VERSION_bifunctors(5,6,0) && !MIN_VERSION_base(4,8,0) instance Bifunctor.Bifunctor MyType where ... #endif ``` ```hs -- For Bifoldable and Bitraversable instances import qualified "bifunctor-classes-compat" Data.Bifoldable as BifoldableCompat import qualified "bifunctor-classes-compat" Data.Bitraversable as BitraversableCompat #if !MIN_VERSION_bifunctors(5,6,0) && !MIN_VERSION_base(4,10,0) import qualified "bifunctors" Data.Bifoldable as Bifoldable import qualified "bifunctors" Data.Bitraversable as Bitraversable #endif instance BifoldableCompat.Bifoldable MyType where ... instance BitraversableCompat.Bitraversable MyType where ... #if !MIN_VERSION_bifunctors(5,6,0) && !MIN_VERSION_base(4,10,0) instance Bifoldable.Bifoldable MyType where ... instance Bitraversable.Bitraversable MyType where ... #endif ``` If your package does nothing but define instances of `Bifunctor` _et al._, you may consider replacing your `bifunctors` dependency with `bifunctor-classes-compat` to reduce your dependency footprint. If you do, it is strongly recommended that you bump your package's major version number so that your users are alerted to the details of the migration. * Define a `Foldable1` instance for `Joker`, and define `Bifoldable1` instances for `Biff`, `Clown`, `Flip`, `Join`, `Joker`, `Product`, `Tannen`, and `WrappedBifunctor`. These instances were originally defined in the `semigroupoids` library, and they have now been migrated to `bifunctors` as a side effect of adapting to [this Core Libraries Proposal](https://github.com/haskell/core-libraries-committee/issues/9), which adds `Foldable1` and `Bifoldable1` to `base`. 5.5.15 [2023.02.27] ------------------- * Support `th-abstraction-0.5.*`. 5.5.14 [2022.12.07] ------------------- * Define `Functor`, `Foldable`, and `Traversable` instances for `Sum` and `Product`. 5.5.13 [2022.09.12] ------------------- * Make the `Biapplicative` instances for tuples lazy, to match their `Bifunctor` instances. 5.5.12 [2022.05.07] ------------------- * Backport an upstream GHC change which removes the default implementation of `bitraverse`. Per the discussion in https://github.com/haskell/core-libraries-committee/issues/47, this default implementation was completely broken, as attempting to use it would always result in an infinite loop. 5.5.11 [2021.04.30] ------------------- * Allow building with `template-haskell-2.18` (GHC 9.2). 5.5.10 [2021.01.21] ------------------- * Fix a bug in which `deriveBifoldable` could generate code that triggers `-Wunused-matches` warnings. 5.5.9 [2020.12.30] ------------------ * Explicitly mark modules as Safe or Trustworthy. 5.5.8 [2020.10.01] ------------------ * Fix a bug in which `deriveBifunctor` would fail on sufficiently complex uses of rank-n types in constructor fields. * Fix a bug in which `deriveBiunctor` and related functions would needlessly reject data types whose two last type parameters appear as oversaturated arguments to a type family. 5.5.7 [2020.01.29] ------------------ * Add `Data.Bifunctor.Biap`. 5.5.6 [2019.11.26] ------------------ * Add `Category`, `Arrow`, `ArrowChoice`, `ArrowLoop`, `ArrowZero`, and `ArrowPlus` instances for `Data.Bifunctor.Product`. 5.5.5 [2019.08.27] ------------------ * Add `Eq{1,2}`, `Ord{1,2}`, `Read{1,2}`, and `Show{1,2}` instances for data types in the `Data.Bifunctor.*` module namespace where possible. The operative phrase is "where possible" since many of these instances require the use of `Eq2`/`Ord2`/`Read2`/`Show2`, which are not available when built against `transformers-0.4.*`. 5.5.4 [2019.04.26] ------------------ * Support `th-abstraction-0.3` or later. * Don't incur a `semigroup` dependency on recent GHCs. 5.5.3 [2018.07.04] ------------------ * Make `biliftA2` a class method of `Biapplicative`. * Add the `traverseBia`, `sequenceBia`, and `traverseBiaWith` functions for traversing a `Traversable` container in a `Biapplicative`. * Avoid incurring some dependencies when using recent GHCs. 5.5.2 [2018.02.06] ------------------ * Don't enable `Safe` on GHC 7.2. 5.5.1 [2018.02.04] ------------------ * Test suite fixes for GHC 8.4. 5.5 [2017.12.07] ---------------- * `Data.Bifunctor.TH` now derives `bimap`/`bitraverse` implementations for empty data types that are strict in the argument. * `Data.Bifunctor.TH` no longer derives `bifoldr`/`bifoldMap` implementations that error on empty data types. Instead, they simply return the folded state (for `bifoldr`) or `mempty` (for `bifoldMap`). * When using `Data.Bifunctor.TH` to derive `Bifunctor` or `Bitraversable` instances for data types where the last two type variables are at phantom roles, generated `bimap`/`bitraverse` implementations now use `coerce` for efficiency. * Add `Options` to `Data.Bifunctor.TH`, along with variants of existing functions that take `Options` as an argument. For now, the only configurable option is whether derived instances for empty data types should use the `EmptyCase` extension (this is disabled by default). 5.4.2 ----- * Make `deriveBitraversable` use `liftA2` in derived implementations of `bitraverse` when possible, now that `liftA2` is a class method of `Applicative` (as of GHC 8.2) * Backport slightly more efficient implementations of `bimapDefault` and `bifoldMapDefault` 5.4.1 ----- * Add explicit `Safe`, `Trustworthy`, and `Unsafe` annotations. In particular, annotate the `Data.Bifoldable` module as `Trustworthy` (previously, it was inferred to be `Unsafe`). 5.4 --- * Only export `Data.Bifoldable` and `Data.Bitraversable` when building on GHC < 8.1, otherwise they come from `base` * Allow TH derivation of `Bifunctor` and `Bifoldable` instances for datatypes containing unboxed tuple types 5.3 --- * Added `bifoldr1`, `bifoldl1`, `bimsum`, `biasum`, `binull`, `bilength`, `bielem`, `bimaximum`, `biminimum`, `bisum`, `biproduct`, `biand`, `bior`, `bimaximumBy`, `biminimumBy`, `binotElem`, and `bifind` to `Data.Bifoldable` * Added `Bifunctor`, `Bifoldable`, and `Bitraversable` instances for `GHC.Generics.K1` * TH code no longer generates superfluous `mempty` or `pure` subexpressions in derived `Bifoldable` or `Bitraversable` instances, respectively 5.2.1 ---- * Added `Bifoldable` and `Bitraversable` instances for `Constant` from `transformers` * `Data.Bifunctor.TH` now compiles warning-free on GHC 8.0 5.2 ----- * Added several `Arrow`-like instances for `Tannen` so we can use it as the Cayley construction if needed. * Added `Data.Bifunctor.Sum` * Added `BifunctorFunctor`, `BifunctorMonad` and `BifunctorComonad`. * Backported `Bifunctor Constant` instance from `transformers` 5.1 --- * Added `Data.Bifunctor.Fix` * Added `Data.Bifunctor.TH`, which permits `TemplateHaskell`-based deriving of `Bifunctor`, `Bifoldable` and `Bitraversable` instances. * Simplified `Bitraversable`. 5 - * Inverted the dependency on `semigroupoids`. We can support a much wider array of `base` versions than it can. * Added flags 4.2.1 ----- * Support `Arg` from `semigroups` 0.16.2 * Fixed a typo. 4.2 --- * Bumped dependency on `tagged`, which is required to build cleanly on GHC 7.9+ * Only export `Data.Bifunctor` when building on GHC < 7.9, otherwise it comes from `base`. 4.1.1.1 ------- * Added documentation for 'Bifoldable' and 'Bitraversable' 4.1.1 ----- * Added `Data.Bifunctor.Join` * Fixed improper lower bounds on `base` 4.1.0.1 ------- * Updated to BSD 2-clause license 4.1 --- * Added product bifunctors 4.0 --- * Compatibility with `semigroupoids` 4.0 3.2 --- * Added missing product instances for `Biapplicative` and `Biapply`. 3.1 ----- * Added `Data.Biapplicative`. * Added the `Clown` and `Joker` bifunctors from Conor McBride's "Clowns to the left of me, Jokers to the right." * Added instances for `Const`, higher tuples * Added `Tagged` instances. 3.0.4 ----- * Added `Data.Bifunctor.Flip` and `Data.Bifunctor.Wrapped`. 3.0.3 --- * Removed upper bounds from my other package dependencies bifunctors-5.6.2/LICENSE0000644000000000000000000000236407346545000013105 0ustar0000000000000000Copyright 2008-2016 Edward Kmett All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. bifunctors-5.6.2/README.markdown0000644000000000000000000000075507346545000014603 0ustar0000000000000000bifunctors ========== [![Hackage](https://img.shields.io/hackage/v/bifunctors.svg)](https://hackage.haskell.org/package/bifunctors) [![Build Status](https://github.com/ekmett/bifunctors/workflows/Haskell-CI/badge.svg)](https://github.com/ekmett/bifunctors/actions?query=workflow%3AHaskell-CI) Contact Information ------------------- Contributions and bug reports are welcome! Please feel free to contact me through github or on the #haskell IRC channel on irc.freenode.net. -Edward Kmett bifunctors-5.6.2/Setup.lhs0000644000000000000000000000016507346545000013705 0ustar0000000000000000#!/usr/bin/runhaskell > module Main (main) where > import Distribution.Simple > main :: IO () > main = defaultMain bifunctors-5.6.2/bifunctors.cabal0000644000000000000000000000620107346545000015234 0ustar0000000000000000cabal-version: 1.24 name: bifunctors category: Data, Functors version: 5.6.2 license: BSD3 license-file: LICENSE author: Edward A. Kmett maintainer: Edward A. Kmett stability: provisional homepage: http://github.com/ekmett/bifunctors/ bug-reports: http://github.com/ekmett/bifunctors/issues copyright: Copyright (C) 2008-2016 Edward A. Kmett synopsis: Bifunctors description: Bifunctors. build-type: Simple tested-with: GHC == 8.0.2 , GHC == 8.2.2 , GHC == 8.4.4 , GHC == 8.6.5 , GHC == 8.8.4 , GHC == 8.10.7 , GHC == 9.0.2 , GHC == 9.2.8 , GHC == 9.4.8 , GHC == 9.6.4 , GHC == 9.8.2 , GHC == 9.10.1 extra-source-files: CHANGELOG.markdown README.markdown source-repository head type: git location: https://github.com/ekmett/bifunctors.git flag tagged default: True manual: True description: You can disable the use of the `tagged` package using `-f-tagged`. . Disabing this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. library hs-source-dirs: src build-depends: base >= 4.9 && < 5, assoc >= 1.1 && < 1.2, comonad >= 5.0.7 && < 6, containers >= 0.5.7.1 && < 0.8, template-haskell >= 2.11 && < 2.23, th-abstraction >= 0.4.2.0 && < 0.8, transformers >= 0.5 && < 0.7 if !impl(ghc >= 8.2) build-depends: bifunctor-classes-compat >= 0.1 && < 0.2, transformers-compat >= 0.6 && < 0.8 if flag(tagged) build-depends: tagged >= 0.8.6 && < 1 if impl(ghc<8.1) reexported-modules: Data.Bifoldable , Data.Bitraversable if !impl(ghc >= 9.6) build-depends: foldable1-classes-compat >= 0.1 && < 0.2 exposed-modules: Data.Biapplicative Data.Bifunctor.Biap Data.Bifunctor.Biff Data.Bifunctor.Clown Data.Bifunctor.Fix Data.Bifunctor.Flip Data.Bifunctor.Functor Data.Bifunctor.Join Data.Bifunctor.Joker Data.Bifunctor.Product Data.Bifunctor.Sum Data.Bifunctor.Tannen Data.Bifunctor.TH Data.Bifunctor.Wrapped other-modules: Data.Bifunctor.TH.Internal ghc-options: -Wall default-language: Haskell2010 if impl(ghc >= 9.0) -- these flags may abort compilation with GHC-8.10 -- https://gitlab.haskell.org/ghc/ghc/-/merge_requests/3295 ghc-options: -Winferred-safe-imports -Wmissing-safe-haskell-mode test-suite bifunctors-spec type: exitcode-stdio-1.0 hs-source-dirs: tests main-is: Spec.hs other-modules: BifunctorSpec T89Spec ghc-options: -Wall if impl(ghc >= 8.6) ghc-options: -Wno-star-is-type default-language: Haskell2010 build-tool-depends: hspec-discover:hspec-discover >= 1.8 build-depends: base >= 4 && < 5, bifunctors, hspec >= 1.8, QuickCheck >= 2 && < 3, template-haskell, transformers, transformers-compat bifunctors-5.6.2/src/Data/0000755000000000000000000000000007346545000013533 5ustar0000000000000000bifunctors-5.6.2/src/Data/Biapplicative.hs0000644000000000000000000002460207346545000016647 0ustar0000000000000000{-# LANGUAGE CPP #-} {-# LANGUAGE GADTs #-} {-# LANGUAGE RankNTypes #-} {-# LANGUAGE ScopedTypeVariables #-} {-# LANGUAGE Trustworthy #-} ----------------------------------------------------------------------------- -- | -- Copyright : (C) 2011-2015 Edward Kmett -- License : BSD-style (see the file LICENSE) -- -- Maintainer : Edward Kmett -- Stability : provisional -- Portability : portable -- ---------------------------------------------------------------------------- module Data.Biapplicative ( -- * Biapplicative bifunctors Biapplicative(..) , (<<$>>) , (<<**>>) , biliftA3 , traverseBia , sequenceBia , traverseBiaWith , module Data.Bifunctor ) where import Control.Applicative import Data.Bifunctor import Data.Functor.Identity import Data.Semigroup (Arg(..)) import GHC.Exts (inline) #ifdef MIN_VERSION_tagged import Data.Tagged #endif infixl 4 <<$>>, <<*>>, <<*, *>>, <<**>> (<<$>>) :: (a -> b) -> a -> b (<<$>>) = id {-# INLINE (<<$>>) #-} class Bifunctor p => Biapplicative p where {-# MINIMAL bipure, ((<<*>>) | biliftA2 ) #-} bipure :: a -> b -> p a b (<<*>>) :: p (a -> b) (c -> d) -> p a c -> p b d (<<*>>) = biliftA2 id id {-# INLINE (<<*>>) #-} -- | Lift binary functions biliftA2 :: (a -> b -> c) -> (d -> e -> f) -> p a d -> p b e -> p c f biliftA2 f g a b = bimap f g <<$>> a <<*>> b {-# INLINE biliftA2 #-} -- | -- @ -- a '*>>' b ≡ 'bimap' ('const' 'id') ('const' 'id') '<<$>>' a '<<*>>' b -- @ (*>>) :: p a b -> p c d -> p c d a *>> b = biliftA2 (const id) (const id) a b {-# INLINE (*>>) #-} -- | -- @ -- a '<<*' b ≡ 'bimap' 'const' 'const' '<<$>>' a '<<*>>' b -- @ (<<*) :: p a b -> p c d -> p a b a <<* b = biliftA2 const const a b {-# INLINE (<<*) #-} (<<**>>) :: Biapplicative p => p a c -> p (a -> b) (c -> d) -> p b d (<<**>>) = biliftA2 (flip id) (flip id) {-# INLINE (<<**>>) #-} -- | Lift ternary functions biliftA3 :: Biapplicative w => (a -> b -> c -> d) -> (e -> f -> g -> h) -> w a e -> w b f -> w c g -> w d h biliftA3 f g a b c = biliftA2 f g a b <<*>> c {-# INLINE biliftA3 #-} -- | Traverse a 'Traversable' container in a 'Biapplicative'. -- -- 'traverseBia' satisfies the following properties: -- -- [/Pairing/] -- -- @'traverseBia' (,) t = (t, t)@ -- -- [/Composition/] -- -- @'traverseBia' ('Data.Bifunctor.Biff.Biff' . 'bimap' g h . f) = 'Data.Bifunctor.Biff.Biff' . 'bimap' ('traverse' g) ('traverse' h) . 'traverseBia' f@ -- -- @'traverseBia' ('Data.Bifunctor.Tannen.Tannen' . 'fmap' f . g) = 'Data.Bifunctor.Tannen.Tannen' . 'fmap' ('traverseBia' f) . 'traverse' g@ -- -- [/Naturality/] -- -- @ t . 'traverseBia' f = 'traverseBia' (t . f) @ -- -- for every biapplicative transformation @t@. -- -- A /biapplicative transformation/ from a 'Biapplicative' @P@ to a 'Biapplicative' @Q@ -- is a function -- -- @t :: P a b -> Q a b@ -- -- preserving the 'Biapplicative' operations. That is, -- -- * @t ('bipure' x y) = 'bipure' x y@ -- -- * @t (x '<<*>>' y) = t x '<<*>>' t y@ -- -- === Performance note -- -- 'traverseBia' is fairly efficient, and uses compiler rewrite rules -- to be even more efficient for a few important types like @[]@. However, -- if performance is critical, you might consider writing a container-specific -- implementation. traverseBia :: (Traversable t, Biapplicative p) => (a -> p b c) -> t a -> p (t b) (t c) traverseBia = inline (traverseBiaWith traverse) -- We explicitly inline traverseBiaWith because it seems likely to help -- specialization. I'm not much of an expert at the inlining business, -- so I won't mind if someone else decides to do this differently. -- We use a staged INLINABLE so we can rewrite traverseBia to specialized -- versions for a few important types. {-# INLINABLE [1] traverseBia #-} -- | Perform all the 'Biapplicative' actions in a 'Traversable' container -- and produce a container with all the results. -- -- @ -- sequenceBia = 'traverseBia' id -- @ sequenceBia :: (Traversable t, Biapplicative p) => t (p b c) -> p (t b) (t c) sequenceBia = inline (traverseBia id) {-# INLINABLE sequenceBia #-} -- | A version of 'traverseBia' that doesn't care how the traversal is -- done. -- -- @ -- 'traverseBia' = traverseBiaWith traverse -- @ traverseBiaWith :: forall p a b c s t. Biapplicative p => (forall f x. Applicative f => (a -> f x) -> s -> f (t x)) -> (a -> p b c) -> s -> p (t b) (t c) traverseBiaWith trav p s = smash p (trav One s) {-# INLINABLE traverseBiaWith #-} smash :: forall p t a b c. Biapplicative p => (a -> p b c) -> (forall x. Mag a x (t x)) -> p (t b) (t c) smash p m = go m m where go :: forall x y. Mag a b x -> Mag a c y -> p x y go (Pure t) (Pure u) = bipure t u go (Map f x) (Map g y) = bimap f g (go x y) go (Ap fs xs) (Ap gs ys) = go fs gs <<*>> go xs ys #if MIN_VERSION_base(4,10,0) go (LiftA2 f xs ys) (LiftA2 g zs ws) = biliftA2 f g (go xs zs) (go ys ws) #endif go (One x) (One _) = p x go _ _ = impossibleError {-# INLINABLE smash #-} -- Let's not end up with a bunch of CallStack junk in the smash -- unfolding. impossibleError :: a impossibleError = error "Impossible: the arguments are always the same." -- This is used to reify a traversal for 'traverseBia'. It's a somewhat -- bogus 'Functor' and 'Applicative' closely related to 'Magma' from the -- @lens@ package. Valid traversals don't use (<$), (<*), or (*>), so -- we leave them out. We offer all the rest of the Functor and Applicative -- operations to improve performance: we generally want to keep the structure -- as small as possible. We might even consider using RULES to widen lifts -- when we can: -- -- liftA2 f x y <*> z ==> liftA3 f x y z, -- -- etc., up to the pointer tagging limit. But we do need to be careful. I don't -- *think* GHC will ever inline the traversal into the go function (because that -- would duplicate work), but if it did, and if different RULES fired for the -- two copies, everything would break horribly. -- -- Note: if it's necessary for some reason, we *could* relax GADTs to -- ExistentialQuantification by changing the type of One to -- -- One :: (b -> c) -> a -> Mag a b c -- -- where the function will always end up being id. But we allocate a *lot* -- of One constructors, so this would definitely be bad for performance. data Mag a b t where Pure :: t -> Mag a b t Map :: (x -> t) -> Mag a b x -> Mag a b t Ap :: Mag a b (t -> u) -> Mag a b t -> Mag a b u #if MIN_VERSION_base(4,10,0) LiftA2 :: (t -> u -> v) -> Mag a b t -> Mag a b u -> Mag a b v #endif One :: a -> Mag a b b instance Functor (Mag a b) where fmap = Map instance Applicative (Mag a b) where pure = Pure (<*>) = Ap #if MIN_VERSION_base(4,10,0) liftA2 = LiftA2 #endif -- Rewrite rules for traversing a few important types. These avoid the overhead -- of allocating and matching on a Mag. {-# RULES "traverseBia/list" forall f t. traverseBia f t = traverseBiaList f t "traverseBia/Maybe" forall f t. traverseBia f t = traverseBiaMaybe f t "traverseBia/Either" forall f t. traverseBia f t = traverseBiaEither f t "traverseBia/Identity" forall f t. traverseBia f t = traverseBiaIdentity f t "traverseBia/Const" forall f t. traverseBia f t = traverseBiaConst f t "traverseBia/Pair" forall f t. traverseBia f t = traverseBiaPair f t #-} traverseBiaList :: Biapplicative p => (a -> p b c) -> [a] -> p [b] [c] traverseBiaList f = foldr go (bipure [] []) where go x r = biliftA2 (:) (:) (f x) r traverseBiaMaybe :: Biapplicative p => (a -> p b c) -> Maybe a -> p (Maybe b) (Maybe c) traverseBiaMaybe _f Nothing = bipure Nothing Nothing traverseBiaMaybe f (Just x) = bimap Just Just (f x) traverseBiaEither :: Biapplicative p => (a -> p b c) -> Either e a -> p (Either e b) (Either e c) traverseBiaEither f (Right x) = bimap Right Right (f x) traverseBiaEither _f (Left (e :: e)) = bipure m m where m :: Either e x m = Left e traverseBiaIdentity :: Biapplicative p => (a -> p b c) -> Identity a -> p (Identity b) (Identity c) traverseBiaIdentity f (Identity x) = bimap Identity Identity (f x) traverseBiaConst :: Biapplicative p => (a -> p b c) -> Const x a -> p (Const x b) (Const x c) traverseBiaConst _f (Const x) = bipure (Const x) (Const x) traverseBiaPair :: Biapplicative p => (a -> p b c) -> (e, a) -> p (e, b) (e, c) traverseBiaPair f (x,y) = bimap ((,) x) ((,) x) (f y) ---------------------------------------------- -- -- Instances instance Biapplicative (,) where bipure = (,) {-# INLINE bipure #-} ~(f, g) <<*>> ~(a, b) = (f a, g b) {-# INLINE (<<*>>) #-} biliftA2 f g ~(x, y) ~(a, b) = (f x a, g y b) {-# INLINE biliftA2 #-} instance Biapplicative Arg where bipure = Arg {-# INLINE bipure #-} Arg f g <<*>> Arg a b = Arg (f a) (g b) {-# INLINE (<<*>>) #-} biliftA2 f g (Arg x y) (Arg a b) = Arg (f x a) (g y b) {-# INLINE biliftA2 #-} instance Monoid x => Biapplicative ((,,) x) where bipure = (,,) mempty {-# INLINE bipure #-} ~(x, f, g) <<*>> ~(x', a, b) = (mappend x x', f a, g b) {-# INLINE (<<*>>) #-} instance (Monoid x, Monoid y) => Biapplicative ((,,,) x y) where bipure = (,,,) mempty mempty {-# INLINE bipure #-} ~(x, y, f, g) <<*>> ~(x', y', a, b) = (mappend x x', mappend y y', f a, g b) {-# INLINE (<<*>>) #-} instance (Monoid x, Monoid y, Monoid z) => Biapplicative ((,,,,) x y z) where bipure = (,,,,) mempty mempty mempty {-# INLINE bipure #-} ~(x, y, z, f, g) <<*>> ~(x', y', z', a, b) = (mappend x x', mappend y y', mappend z z', f a, g b) {-# INLINE (<<*>>) #-} instance (Monoid x, Monoid y, Monoid z, Monoid w) => Biapplicative ((,,,,,) x y z w) where bipure = (,,,,,) mempty mempty mempty mempty {-# INLINE bipure #-} ~(x, y, z, w, f, g) <<*>> ~(x', y', z', w', a, b) = (mappend x x', mappend y y', mappend z z', mappend w w', f a, g b) {-# INLINE (<<*>>) #-} instance (Monoid x, Monoid y, Monoid z, Monoid w, Monoid v) => Biapplicative ((,,,,,,) x y z w v) where bipure = (,,,,,,) mempty mempty mempty mempty mempty {-# INLINE bipure #-} ~(x, y, z, w, v, f, g) <<*>> ~(x', y', z', w', v', a, b) = (mappend x x', mappend y y', mappend z z', mappend w w', mappend v v', f a, g b) {-# INLINE (<<*>>) #-} #ifdef MIN_VERSION_tagged instance Biapplicative Tagged where bipure _ b = Tagged b {-# INLINE bipure #-} Tagged f <<*>> Tagged x = Tagged (f x) {-# INLINE (<<*>>) #-} #endif instance Biapplicative Const where bipure a _ = Const a {-# INLINE bipure #-} Const f <<*>> Const x = Const (f x) {-# INLINE (<<*>>) #-} bifunctors-5.6.2/src/Data/Bifunctor/0000755000000000000000000000000007346545000015466 5ustar0000000000000000bifunctors-5.6.2/src/Data/Bifunctor/Biap.hs0000644000000000000000000000635607346545000016707 0ustar0000000000000000{-# LANGUAGE CPP #-} {-# LANGUAGE DeriveGeneric #-} {-# LANGUAGE EmptyDataDecls #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE DeriveTraversable #-} {-# LANGUAGE GeneralizedNewtypeDeriving #-} {-# LANGUAGE ScopedTypeVariables #-} {-# LANGUAGE TypeFamilies #-} -- This module uses GND {-# LANGUAGE Trustworthy #-} ----------------------------------------------------------------------------- -- | -- Copyright : (C) 2008-2016 Edward Kmett -- License : BSD-style (see the file LICENSE) -- -- Maintainer : Edward Kmett -- Stability : provisional -- Portability : portable -- ---------------------------------------------------------------------------- module Data.Bifunctor.Biap ( Biap(..) ) where import Control.Applicative import Control.Monad import qualified Control.Monad.Fail as Fail (MonadFail) import Data.Biapplicative import Data.Bifoldable import Data.Bitraversable import Data.Functor.Classes import qualified Data.Semigroup as S import GHC.Generics -- | Pointwise lifting of a class over two arguments, using -- 'Biapplicative'. -- -- Classes that can be lifted include 'Monoid', 'Num' and -- 'Bounded'. Each method of those classes can be defined as lifting -- themselves over each argument of 'Biapplicative'. -- -- @ -- mempty = bipure mempty mempty -- minBound = bipure minBound minBound -- maxBound = bipure maxBound maxBound -- fromInteger n = bipure (fromInteger n) (fromInteger n) -- -- negate = bimap negate negate -- -- (+) = biliftA2 (+) (+) -- (<>) = biliftA2 (<>) (<>) -- @ -- -- 'Biap' is to 'Biapplicative' as 'Data.Monoid.Ap' is to -- 'Applicative'. -- -- 'Biap' can be used with @DerivingVia@ to derive a numeric instance -- for pairs: -- -- @ -- newtype Numpair a = Np (a, a) -- deriving (S.Semigroup, Monoid, Num, Bounded) -- via Biap (,) a a -- @ -- newtype Biap bi a b = Biap { getBiap :: bi a b } deriving ( Eq , Ord , Show , Read , Enum , Functor , Foldable , Traversable , Alternative , Applicative , Generic , Generic1 , Monad , Fail.MonadFail , MonadPlus , Eq1 , Ord1 , Bifunctor , Biapplicative , Bifoldable , Eq2 , Ord2 ) instance Bitraversable bi => Bitraversable (Biap bi) where bitraverse f g (Biap as) = Biap <$> bitraverse f g as instance (Biapplicative bi, S.Semigroup a, S.Semigroup b) => S.Semigroup (Biap bi a b) where (<>) = biliftA2 (S.<>) (S.<>) instance (Biapplicative bi, Monoid a, Monoid b) => Monoid (Biap bi a b) where mempty = bipure mempty mempty #if !(MIN_VERSION_base(4,11,0)) mappend = biliftA2 mappend mappend #endif instance (Biapplicative bi, Bounded a, Bounded b) => Bounded (Biap bi a b) where minBound = bipure minBound minBound maxBound = bipure maxBound maxBound instance (Biapplicative bi, Num a, Num b) => Num (Biap bi a b) where (+) = biliftA2 (+) (+) (*) = biliftA2 (*) (*) negate = bimap negate negate abs = bimap abs abs signum = bimap signum signum fromInteger n = bipure (fromInteger n) (fromInteger n) bifunctors-5.6.2/src/Data/Bifunctor/Biff.hs0000644000000000000000000001032507346545000016671 0ustar0000000000000000{-# LANGUAGE DeriveGeneric #-} {-# LANGUAGE EmptyDataDecls #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE PolyKinds #-} {-# LANGUAGE Safe #-} {-# LANGUAGE StandaloneDeriving #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE TypeOperators #-} ----------------------------------------------------------------------------- -- | -- Copyright : (C) 2008-2016 Edward Kmett -- License : BSD-style (see the file LICENSE) -- -- Maintainer : Edward Kmett -- Stability : provisional -- Portability : portable -- ---------------------------------------------------------------------------- module Data.Bifunctor.Biff ( Biff(..) ) where import Data.Biapplicative import Data.Bifoldable import Data.Bifoldable1 (Bifoldable1(..)) import Data.Bifunctor.Swap (Swap (..)) import Data.Bitraversable import Data.Foldable1 (Foldable1(..)) import Data.Functor.Classes import GHC.Generics -- | Compose two 'Functor's on the inside of a 'Bifunctor'. newtype Biff p f g a b = Biff { runBiff :: p (f a) (g b) } deriving (Eq, Ord, Show, Read, Generic) deriving instance Functor (p (f a)) => Generic1 (Biff p f g a) instance (Eq2 p, Eq1 f, Eq1 g, Eq a) => Eq1 (Biff p f g a) where liftEq = liftEq2 (==) instance (Eq2 p, Eq1 f, Eq1 g) => Eq2 (Biff p f g) where liftEq2 f g (Biff x) (Biff y) = liftEq2 (liftEq f) (liftEq g) x y instance (Ord2 p, Ord1 f, Ord1 g, Ord a) => Ord1 (Biff p f g a) where liftCompare = liftCompare2 compare instance (Ord2 p, Ord1 f, Ord1 g) => Ord2 (Biff p f g) where liftCompare2 f g (Biff x) (Biff y) = liftCompare2 (liftCompare f) (liftCompare g) x y instance (Read2 p, Read1 f, Read1 g, Read a) => Read1 (Biff p f g a) where liftReadsPrec = liftReadsPrec2 readsPrec readList instance (Read2 p, Read1 f, Read1 g) => Read2 (Biff p f g) where liftReadsPrec2 rp1 rl1 rp2 rl2 p = readParen (p > 10) $ \s0 -> do ("Biff", s1) <- lex s0 ("{", s2) <- lex s1 ("runBiff", s3) <- lex s2 (x, s4) <- liftReadsPrec2 (liftReadsPrec rp1 rl1) (liftReadList rp1 rl1) (liftReadsPrec rp2 rl2) (liftReadList rp2 rl2) 0 s3 ("}", s5) <- lex s4 return (Biff x, s5) instance (Show2 p, Show1 f, Show1 g, Show a) => Show1 (Biff p f g a) where liftShowsPrec = liftShowsPrec2 showsPrec showList instance (Show2 p, Show1 f, Show1 g) => Show2 (Biff p f g) where liftShowsPrec2 sp1 sl1 sp2 sl2 p (Biff x) = showParen (p > 10) $ showString "Biff {runBiff = " . liftShowsPrec2 (liftShowsPrec sp1 sl1) (liftShowList sp1 sl1) (liftShowsPrec sp2 sl2) (liftShowList sp2 sl2) 0 x . showChar '}' instance (Bifunctor p, Functor f, Functor g) => Bifunctor (Biff p f g) where first f = Biff . first (fmap f) . runBiff {-# INLINE first #-} second f = Biff . second (fmap f) . runBiff {-# INLINE second #-} bimap f g = Biff . bimap (fmap f) (fmap g) . runBiff {-# INLINE bimap #-} instance (Bifunctor p, Functor g) => Functor (Biff p f g a) where fmap f = Biff . second (fmap f) . runBiff {-# INLINE fmap #-} instance (Biapplicative p, Applicative f, Applicative g) => Biapplicative (Biff p f g) where bipure a b = Biff (bipure (pure a) (pure b)) {-# INLINE bipure #-} Biff fg <<*>> Biff xy = Biff (bimap (<*>) (<*>) fg <<*>> xy) {-# INLINE (<<*>>) #-} instance (Bifoldable p, Foldable g) => Foldable (Biff p f g a) where foldMap f = bifoldMap (const mempty) (foldMap f) . runBiff {-# INLINE foldMap #-} instance (Bifoldable p, Foldable f, Foldable g) => Bifoldable (Biff p f g) where bifoldMap f g = bifoldMap (foldMap f) (foldMap g) . runBiff {-# INLINE bifoldMap #-} instance (Bifoldable1 p, Foldable1 f, Foldable1 g) => Bifoldable1 (Biff p f g) where bifoldMap1 f g = bifoldMap1 (foldMap1 f) (foldMap1 g) . runBiff {-# INLINE bifoldMap1 #-} instance (Bitraversable p, Traversable g) => Traversable (Biff p f g a) where traverse f = fmap Biff . bitraverse pure (traverse f) . runBiff {-# INLINE traverse #-} instance (Bitraversable p, Traversable f, Traversable g) => Bitraversable (Biff p f g) where bitraverse f g = fmap Biff . bitraverse (traverse f) (traverse g) . runBiff {-# INLINE bitraverse #-} -- | @since 5.6.1 instance (f ~ g, Functor f, Swap p) => Swap (Biff p f g) where swap = Biff . swap . runBiff bifunctors-5.6.2/src/Data/Bifunctor/Clown.hs0000644000000000000000000000736107346545000017113 0ustar0000000000000000{-# LANGUAGE DeriveGeneric #-} {-# LANGUAGE EmptyDataDecls #-} {-# LANGUAGE PolyKinds #-} {-# LANGUAGE Safe #-} {-# LANGUAGE TypeFamilies #-} ----------------------------------------------------------------------------- -- | -- Copyright : (C) 2008-2016 Edward Kmett -- License : BSD-style (see the file LICENSE) -- -- Maintainer : Edward Kmett -- Stability : provisional -- Portability : portable -- -- From the Functional Pearl \"Clowns to the Left of me, Jokers to the Right: Dissecting Data Structures\" -- by Conor McBride. ---------------------------------------------------------------------------- module Data.Bifunctor.Clown ( Clown(..) ) where import Data.Biapplicative import Data.Bifoldable import Data.Bifoldable1 (Bifoldable1(..)) import Data.Bitraversable import Data.Foldable1 (Foldable1(..)) import Data.Functor.Classes import GHC.Generics -- | Make a 'Functor' over the first argument of a 'Bifunctor'. -- -- Mnemonic: C__l__owns to the __l__eft (parameter of the Bifunctor), -- joke__r__s to the __r__ight. newtype Clown f a b = Clown { runClown :: f a } deriving (Eq, Ord, Show, Read, Generic, Generic1) instance (Eq1 f, Eq a) => Eq1 (Clown f a) where liftEq = liftEq2 (==) instance Eq1 f => Eq2 (Clown f) where liftEq2 f _ = eqClown (liftEq f) instance (Ord1 f, Ord a) => Ord1 (Clown f a) where liftCompare = liftCompare2 compare instance Ord1 f => Ord2 (Clown f) where liftCompare2 f _ = compareClown (liftCompare f) instance (Read1 f, Read a) => Read1 (Clown f a) where liftReadsPrec = liftReadsPrec2 readsPrec readList instance Read1 f => Read2 (Clown f) where liftReadsPrec2 rp1 rl1 _ _ = readsPrecClown (liftReadsPrec rp1 rl1) instance (Show1 f, Show a) => Show1 (Clown f a) where liftShowsPrec = liftShowsPrec2 showsPrec showList instance Show1 f => Show2 (Clown f) where liftShowsPrec2 sp1 sl1 _ _ = showsPrecClown (liftShowsPrec sp1 sl1) eqClown :: (f a1 -> f a2 -> Bool) -> Clown f a1 b1 -> Clown f a2 b2 -> Bool eqClown eqA (Clown x) (Clown y) = eqA x y compareClown :: (f a1 -> f a2 -> Ordering) -> Clown f a1 b1 -> Clown f a2 b2 -> Ordering compareClown compareA (Clown x) (Clown y) = compareA x y readsPrecClown :: (Int -> ReadS (f a)) -> Int -> ReadS (Clown f a b) readsPrecClown rpA p = readParen (p > 10) $ \s0 -> do ("Clown", s1) <- lex s0 ("{", s2) <- lex s1 ("runClown", s3) <- lex s2 (x, s4) <- rpA 0 s3 ("}", s5) <- lex s4 return (Clown x, s5) showsPrecClown :: (Int -> f a -> ShowS) -> Int -> Clown f a b -> ShowS showsPrecClown spA p (Clown x) = showParen (p > 10) $ showString "Clown {runClown = " . spA 0 x . showChar '}' instance Functor f => Bifunctor (Clown f) where first f = Clown . fmap f . runClown {-# INLINE first #-} second _ = Clown . runClown {-# INLINE second #-} bimap f _ = Clown . fmap f . runClown {-# INLINE bimap #-} instance Functor (Clown f a) where fmap _ = Clown . runClown {-# INLINE fmap #-} instance Applicative f => Biapplicative (Clown f) where bipure a _ = Clown (pure a) {-# INLINE bipure #-} Clown mf <<*>> Clown mx = Clown (mf <*> mx) {-# INLINE (<<*>>) #-} instance Foldable f => Bifoldable (Clown f) where bifoldMap f _ = foldMap f . runClown {-# INLINE bifoldMap #-} instance Foldable1 f => Bifoldable1 (Clown f) where bifoldMap1 f _ = foldMap1 f . runClown {-# INLINE bifoldMap1 #-} instance Foldable (Clown f a) where foldMap _ = mempty {-# INLINE foldMap #-} instance Traversable f => Bitraversable (Clown f) where bitraverse f _ = fmap Clown . traverse f . runClown {-# INLINE bitraverse #-} instance Traversable (Clown f a) where traverse _ = pure . Clown . runClown {-# INLINE traverse #-} bifunctors-5.6.2/src/Data/Bifunctor/Fix.hs0000644000000000000000000000471107346545000016553 0ustar0000000000000000{-# LANGUAGE DeriveGeneric #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE PolyKinds #-} {-# LANGUAGE Safe #-} {-# LANGUAGE StandaloneDeriving #-} {-# LANGUAGE UndecidableInstances #-} ----------------------------------------------------------------------------- -- | -- Module : Data.Bifunctor.Fix -- Copyright : (C) 2008-2016 Edward Kmett -- License : BSD-style (see the file LICENSE) -- -- Maintainer : Edward Kmett -- Stability : provisional -- Portability : non-portable -- ----------------------------------------------------------------------------- module Data.Bifunctor.Fix ( Fix(..) ) where import Data.Biapplicative import Data.Bifoldable import Data.Bitraversable import Data.Functor.Classes import GHC.Generics -- | Greatest fixpoint of a 'Bifunctor' (a 'Functor' over the first argument with zipping). newtype Fix p a = In { out :: p (Fix p a) a } deriving Generic deriving instance Eq (p (Fix p a) a) => Eq (Fix p a) deriving instance Ord (p (Fix p a) a) => Ord (Fix p a) deriving instance Show (p (Fix p a) a) => Show (Fix p a) deriving instance Read (p (Fix p a) a) => Read (Fix p a) instance Eq2 p => Eq1 (Fix p) where liftEq f (In x) (In y) = liftEq2 (liftEq f) f x y instance Ord2 p => Ord1 (Fix p) where liftCompare f (In x) (In y) = liftCompare2 (liftCompare f) f x y instance Read2 p => Read1 (Fix p) where liftReadsPrec rp1 rl1 p = readParen (p > 10) $ \s0 -> do ("In", s1) <- lex s0 ("{", s2) <- lex s1 ("out", s3) <- lex s2 (x, s4) <- liftReadsPrec2 (liftReadsPrec rp1 rl1) (liftReadList rp1 rl1) rp1 rl1 0 s3 ("}", s5) <- lex s4 return (In x, s5) instance Show2 p => Show1 (Fix p) where liftShowsPrec sp1 sl1 p (In x) = showParen (p > 10) $ showString "In {out = " . liftShowsPrec2 (liftShowsPrec sp1 sl1) (liftShowList sp1 sl1) sp1 sl1 0 x . showChar '}' instance Bifunctor p => Functor (Fix p) where fmap f (In p) = In (bimap (fmap f) f p) {-# INLINE fmap #-} instance Biapplicative p => Applicative (Fix p) where pure a = In (bipure (pure a) a) {-# INLINE pure #-} In p <*> In q = In (biliftA2 (<*>) ($) p q) {-# INLINE (<*>) #-} instance Bifoldable p => Foldable (Fix p) where foldMap f (In p) = bifoldMap (foldMap f) f p {-# INLINE foldMap #-} instance Bitraversable p => Traversable (Fix p) where traverse f (In p) = In <$> bitraverse (traverse f) f p {-# INLINE traverse #-} bifunctors-5.6.2/src/Data/Bifunctor/Flip.hs0000644000000000000000000000700407346545000016715 0ustar0000000000000000{-# LANGUAGE DeriveGeneric #-} {-# LANGUAGE PolyKinds #-} {-# LANGUAGE Safe #-} ----------------------------------------------------------------------------- -- | -- Module : Data.Bifunctor.Flip -- Copyright : (C) 2008-2016 Edward Kmett -- License : BSD-style (see the file LICENSE) -- -- Maintainer : Edward Kmett -- Stability : provisional -- Portability : portable -- ---------------------------------------------------------------------------- module Data.Bifunctor.Flip ( Flip(..) ) where import Data.Biapplicative import Data.Bifoldable import Data.Bifoldable1 (Bifoldable1(..)) import Data.Bifunctor.Functor import Data.Bifunctor.Swap (Swap (..)) import Data.Bifunctor.Assoc (Assoc (..)) import Data.Bitraversable import Data.Functor.Classes import GHC.Generics -- | Make a 'Bifunctor' flipping the arguments of a 'Bifunctor'. newtype Flip p a b = Flip { runFlip :: p b a } deriving (Eq, Ord, Show, Read, Generic) instance (Eq2 p, Eq a) => Eq1 (Flip p a) where liftEq = liftEq2 (==) instance Eq2 p => Eq2 (Flip p) where liftEq2 f g (Flip x) (Flip y) = liftEq2 g f x y instance (Ord2 p, Ord a) => Ord1 (Flip p a) where liftCompare = liftCompare2 compare instance Ord2 p => Ord2 (Flip p) where liftCompare2 f g (Flip x) (Flip y) = liftCompare2 g f x y instance (Read2 p, Read a) => Read1 (Flip p a) where liftReadsPrec = liftReadsPrec2 readsPrec readList instance Read2 p => Read2 (Flip p) where liftReadsPrec2 rp1 rl1 rp2 rl2 p = readParen (p > 10) $ \s0 -> do ("Flip", s1) <- lex s0 ("{", s2) <- lex s1 ("runFlip", s3) <- lex s2 (x, s4) <- liftReadsPrec2 rp2 rl2 rp1 rl1 0 s3 ("}", s5) <- lex s4 return (Flip x, s5) instance (Show2 p, Show a) => Show1 (Flip p a) where liftShowsPrec = liftShowsPrec2 showsPrec showList instance Show2 p => Show2 (Flip p) where liftShowsPrec2 sp1 sl1 sp2 sl2 p (Flip x) = showParen (p > 10) $ showString "Flip {runFlip = " . liftShowsPrec2 sp2 sl2 sp1 sl1 0 x . showChar '}' instance Bifunctor p => Bifunctor (Flip p) where first f = Flip . second f . runFlip {-# INLINE first #-} second f = Flip . first f . runFlip {-# INLINE second #-} bimap f g = Flip . bimap g f . runFlip {-# INLINE bimap #-} instance Bifunctor p => Functor (Flip p a) where fmap f = Flip . first f . runFlip {-# INLINE fmap #-} instance Biapplicative p => Biapplicative (Flip p) where bipure a b = Flip (bipure b a) {-# INLINE bipure #-} Flip fg <<*>> Flip xy = Flip (fg <<*>> xy) {-# INLINE (<<*>>) #-} instance Bifoldable p => Bifoldable (Flip p) where bifoldMap f g = bifoldMap g f . runFlip {-# INLINE bifoldMap #-} instance Bifoldable1 p => Bifoldable1 (Flip p) where bifoldMap1 f g = bifoldMap1 g f . runFlip {-# INLINE bifoldMap1 #-} instance Bifoldable p => Foldable (Flip p a) where foldMap f = bifoldMap f (const mempty) . runFlip {-# INLINE foldMap #-} instance Bitraversable p => Bitraversable (Flip p) where bitraverse f g = fmap Flip . bitraverse g f . runFlip {-# INLINE bitraverse #-} instance Bitraversable p => Traversable (Flip p a) where traverse f = fmap Flip . bitraverse f pure . runFlip {-# INLINE traverse #-} instance BifunctorFunctor Flip where bifmap f (Flip p) = Flip (f p) -- | @since 5.6.1 instance Assoc p => Assoc (Flip p) where assoc = Flip . first Flip . unassoc . second runFlip . runFlip unassoc = Flip . second Flip . assoc . first runFlip . runFlip -- | @since 5.6.1 instance Swap p => Swap (Flip p) where swap = Flip . swap . runFlip bifunctors-5.6.2/src/Data/Bifunctor/Functor.hs0000644000000000000000000000231207346545000017440 0ustar0000000000000000{-# LANGUAGE PolyKinds #-} {-# LANGUAGE RankNTypes #-} {-# LANGUAGE Safe #-} {-# LANGUAGE TypeOperators #-} module Data.Bifunctor.Functor ( (:->) , BifunctorFunctor(..) , BifunctorMonad(..) , biliftM , BifunctorComonad(..) , biliftW ) where -- | Using parametricity as an approximation of a natural transformation in two arguments. type (:->) p q = forall a b. p a b -> q a b infixr 0 :-> class BifunctorFunctor t where bifmap :: (p :-> q) -> t p :-> t q class BifunctorFunctor t => BifunctorMonad t where bireturn :: p :-> t p bibind :: (p :-> t q) -> t p :-> t q bibind f = bijoin . bifmap f bijoin :: t (t p) :-> t p bijoin = bibind id {-# MINIMAL bireturn, (bibind | bijoin) #-} biliftM :: BifunctorMonad t => (p :-> q) -> t p :-> t q biliftM f = bibind (bireturn . f) {-# INLINE biliftM #-} class BifunctorFunctor t => BifunctorComonad t where biextract :: t p :-> p biextend :: (t p :-> q) -> t p :-> t q biextend f = bifmap f . biduplicate biduplicate :: t p :-> t (t p) biduplicate = biextend id {-# MINIMAL biextract, (biextend | biduplicate) #-} biliftW :: BifunctorComonad t => (p :-> q) -> t p :-> t q biliftW f = biextend (f . biextract) {-# INLINE biliftW #-} bifunctors-5.6.2/src/Data/Bifunctor/Join.hs0000644000000000000000000000514607346545000016727 0ustar0000000000000000{-# LANGUAGE DeriveGeneric #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE PolyKinds #-} {-# LANGUAGE Safe #-} {-# LANGUAGE StandaloneDeriving #-} {-# LANGUAGE UndecidableInstances #-} ----------------------------------------------------------------------------- -- | -- Copyright : (C) 2008-2016 Edward Kmett -- License : BSD-style (see the file LICENSE) -- -- Maintainer : Edward Kmett -- Stability : provisional -- Portability : non-portable -- ---------------------------------------------------------------------------- module Data.Bifunctor.Join ( Join(..) ) where import Data.Biapplicative import Data.Bifoldable import Data.Bifoldable1 (Bifoldable1(..)) import Data.Bitraversable import Data.Foldable1 (Foldable1(..)) import Data.Functor.Classes import GHC.Generics -- | Make a 'Functor' over both arguments of a 'Bifunctor'. newtype Join p a = Join { runJoin :: p a a } deriving Generic deriving instance Eq (p a a) => Eq (Join p a) deriving instance Ord (p a a) => Ord (Join p a) deriving instance Show (p a a) => Show (Join p a) deriving instance Read (p a a) => Read (Join p a) instance Eq2 p => Eq1 (Join p) where liftEq f (Join x) (Join y) = liftEq2 f f x y instance Ord2 p => Ord1 (Join p) where liftCompare f (Join x) (Join y) = liftCompare2 f f x y instance Read2 p => Read1 (Join p) where liftReadsPrec rp1 rl1 p = readParen (p > 10) $ \s0 -> do ("Join", s1) <- lex s0 ("{", s2) <- lex s1 ("runJoin", s3) <- lex s2 (x, s4) <- liftReadsPrec2 rp1 rl1 rp1 rl1 0 s3 ("}", s5) <- lex s4 return (Join x, s5) instance Show2 p => Show1 (Join p) where liftShowsPrec sp1 sl1 p (Join x) = showParen (p > 10) $ showString "Join {runJoin = " . liftShowsPrec2 sp1 sl1 sp1 sl1 0 x . showChar '}' instance Bifunctor p => Functor (Join p) where fmap f (Join a) = Join (bimap f f a) {-# INLINE fmap #-} instance Biapplicative p => Applicative (Join p) where pure a = Join (bipure a a) {-# INLINE pure #-} Join f <*> Join a = Join (f <<*>> a) {-# INLINE (<*>) #-} Join a *> Join b = Join (a *>> b) {-# INLINE (*>) #-} Join a <* Join b = Join (a <<* b) {-# INLINE (<*) #-} instance Bifoldable p => Foldable (Join p) where foldMap f (Join a) = bifoldMap f f a {-# INLINE foldMap #-} instance Bifoldable1 p => Foldable1 (Join p) where foldMap1 f (Join a) = bifoldMap1 f f a {-# INLINE foldMap1 #-} instance Bitraversable p => Traversable (Join p) where traverse f (Join a) = fmap Join (bitraverse f f a) {-# INLINE traverse #-} sequenceA (Join a) = fmap Join (bisequenceA a) {-# INLINE sequenceA #-} bifunctors-5.6.2/src/Data/Bifunctor/Joker.hs0000644000000000000000000000766307346545000017110 0ustar0000000000000000{-# LANGUAGE DeriveGeneric #-} {-# LANGUAGE EmptyDataDecls #-} {-# LANGUAGE PolyKinds #-} {-# LANGUAGE Safe #-} {-# LANGUAGE TypeFamilies #-} ----------------------------------------------------------------------------- -- | -- Copyright : (C) 2008-2016 Edward Kmett -- License : BSD-style (see the file LICENSE) -- -- Maintainer : Edward Kmett -- Stability : provisional -- Portability : portable -- -- From the Functional Pearl \"Clowns to the Left of me, Jokers to the Right: Dissecting Data Structures\" -- by Conor McBride. ---------------------------------------------------------------------------- module Data.Bifunctor.Joker ( Joker(..) ) where import Data.Biapplicative import Data.Bifoldable import Data.Bifoldable1 (Bifoldable1(..)) import Data.Bitraversable import Data.Foldable1 (Foldable1(..)) import Data.Functor.Classes import GHC.Generics -- | Make a 'Functor' over the second argument of a 'Bifunctor'. -- -- Mnemonic: C__l__owns to the __l__eft (parameter of the Bifunctor), -- joke__r__s to the __r__ight. newtype Joker g a b = Joker { runJoker :: g b } deriving (Eq, Ord, Show, Read, Generic, Generic1) instance Eq1 g => Eq1 (Joker g a) where liftEq g = eqJoker (liftEq g) instance Eq1 g => Eq2 (Joker g) where liftEq2 _ g = eqJoker (liftEq g) instance Ord1 g => Ord1 (Joker g a) where liftCompare g = compareJoker (liftCompare g) instance Ord1 g => Ord2 (Joker g) where liftCompare2 _ g = compareJoker (liftCompare g) instance Read1 g => Read1 (Joker g a) where liftReadsPrec rp rl = readsPrecJoker (liftReadsPrec rp rl) instance Read1 g => Read2 (Joker g) where liftReadsPrec2 _ _ rp2 rl2 = readsPrecJoker (liftReadsPrec rp2 rl2) instance Show1 g => Show1 (Joker g a) where liftShowsPrec sp sl = showsPrecJoker (liftShowsPrec sp sl) instance Show1 g => Show2 (Joker g) where liftShowsPrec2 _ _ sp2 sl2 = showsPrecJoker (liftShowsPrec sp2 sl2) eqJoker :: (g b1 -> g b2 -> Bool) -> Joker g a1 b1 -> Joker g a2 b2 -> Bool eqJoker eqB (Joker x) (Joker y) = eqB x y compareJoker :: (g b1 -> g b2 -> Ordering) -> Joker g a1 b1 -> Joker g a2 b2 -> Ordering compareJoker compareB (Joker x) (Joker y) = compareB x y readsPrecJoker :: (Int -> ReadS (g b)) -> Int -> ReadS (Joker g a b) readsPrecJoker rpB p = readParen (p > 10) $ \s0 -> do ("Joker", s1) <- lex s0 ("{", s2) <- lex s1 ("runJoker", s3) <- lex s2 (x, s4) <- rpB 0 s3 ("}", s5) <- lex s4 return (Joker x, s5) showsPrecJoker :: (Int -> g b -> ShowS) -> Int -> Joker g a b -> ShowS showsPrecJoker spB p (Joker x) = showParen (p > 10) $ showString "Joker {runJoker = " . spB 0 x . showChar '}' instance Functor g => Bifunctor (Joker g) where first _ = Joker . runJoker {-# INLINE first #-} second g = Joker . fmap g . runJoker {-# INLINE second #-} bimap _ g = Joker . fmap g . runJoker {-# INLINE bimap #-} instance Functor g => Functor (Joker g a) where fmap g = Joker . fmap g . runJoker {-# INLINE fmap #-} instance Applicative g => Biapplicative (Joker g) where bipure _ b = Joker (pure b) {-# INLINE bipure #-} Joker mf <<*>> Joker mx = Joker (mf <*> mx) {-# INLINE (<<*>>) #-} instance Foldable g => Bifoldable (Joker g) where bifoldMap _ g = foldMap g . runJoker {-# INLINE bifoldMap #-} instance Foldable1 g => Bifoldable1 (Joker g) where bifoldMap1 _ g = foldMap1 g . runJoker {-# INLINE bifoldMap1 #-} instance Foldable g => Foldable (Joker g a) where foldMap g = foldMap g . runJoker {-# INLINE foldMap #-} instance Foldable1 g => Foldable1 (Joker g a) where foldMap1 g = foldMap1 g . runJoker {-# INLINE foldMap1 #-} instance Traversable g => Bitraversable (Joker g) where bitraverse _ g = fmap Joker . traverse g . runJoker {-# INLINE bitraverse #-} instance Traversable g => Traversable (Joker g a) where traverse g = fmap Joker . traverse g . runJoker {-# INLINE traverse #-} bifunctors-5.6.2/src/Data/Bifunctor/Product.hs0000644000000000000000000001225207346545000017444 0ustar0000000000000000{-# LANGUAGE DeriveFoldable #-} {-# LANGUAGE DeriveFunctor #-} {-# LANGUAGE DeriveGeneric #-} {-# LANGUAGE DeriveTraversable #-} {-# LANGUAGE EmptyDataDecls #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE PolyKinds #-} {-# LANGUAGE Safe #-} {-# LANGUAGE StandaloneDeriving #-} {-# LANGUAGE TypeFamilies #-} ----------------------------------------------------------------------------- -- | -- Copyright : (C) 2008-2016 Jesse Selover, Edward Kmett -- License : BSD-style (see the file LICENSE) -- -- Maintainer : Edward Kmett -- Stability : provisional -- Portability : portable -- -- The product of two bifunctors. ---------------------------------------------------------------------------- module Data.Bifunctor.Product ( Product(..) ) where import qualified Control.Arrow as A import Control.Category import Data.Biapplicative import Data.Bifoldable import Data.Bifoldable1 (Bifoldable1(..)) import Data.Bifunctor.Functor import Data.Bifunctor.Swap (Swap (..)) import Data.Bitraversable import Data.Functor.Classes import qualified Data.Semigroup as S import GHC.Generics import Prelude hiding ((.),id) -- | Form the product of two bifunctors data Product f g a b = Pair (f a b) (g a b) deriving (Eq, Ord, Show, Read, Generic, Generic1) deriving instance (Functor (f a), Functor (g a)) => Functor (Product f g a) deriving instance (Foldable (f a), Foldable (g a)) => Foldable (Product f g a) deriving instance (Traversable (f a), Traversable (g a)) => Traversable (Product f g a) instance (Eq2 f, Eq2 g, Eq a) => Eq1 (Product f g a) where liftEq = liftEq2 (==) instance (Eq2 f, Eq2 g) => Eq2 (Product f g) where liftEq2 f g (Pair x1 y1) (Pair x2 y2) = liftEq2 f g x1 x2 && liftEq2 f g y1 y2 instance (Ord2 f, Ord2 g, Ord a) => Ord1 (Product f g a) where liftCompare = liftCompare2 compare instance (Ord2 f, Ord2 g) => Ord2 (Product f g) where liftCompare2 f g (Pair x1 y1) (Pair x2 y2) = liftCompare2 f g x1 x2 `mappend` liftCompare2 f g y1 y2 instance (Read2 f, Read2 g, Read a) => Read1 (Product f g a) where liftReadsPrec = liftReadsPrec2 readsPrec readList instance (Read2 f, Read2 g) => Read2 (Product f g) where liftReadsPrec2 rp1 rl1 rp2 rl2 = readsData $ readsBinaryWith (liftReadsPrec2 rp1 rl1 rp2 rl2) (liftReadsPrec2 rp1 rl1 rp2 rl2) "Pair" Pair instance (Show2 f, Show2 g, Show a) => Show1 (Product f g a) where liftShowsPrec = liftShowsPrec2 showsPrec showList instance (Show2 f, Show2 g) => Show2 (Product f g) where liftShowsPrec2 sp1 sl1 sp2 sl2 p (Pair x y) = showsBinaryWith (liftShowsPrec2 sp1 sl1 sp2 sl2) (liftShowsPrec2 sp1 sl1 sp2 sl2) "Pair" p x y instance (Bifunctor f, Bifunctor g) => Bifunctor (Product f g) where first f (Pair x y) = Pair (first f x) (first f y) {-# INLINE first #-} second g (Pair x y) = Pair (second g x) (second g y) {-# INLINE second #-} bimap f g (Pair x y) = Pair (bimap f g x) (bimap f g y) {-# INLINE bimap #-} instance (Biapplicative f, Biapplicative g) => Biapplicative (Product f g) where bipure a b = Pair (bipure a b) (bipure a b) {-# INLINE bipure #-} Pair w x <<*>> Pair y z = Pair (w <<*>> y) (x <<*>> z) {-# INLINE (<<*>>) #-} instance (Bifoldable f, Bifoldable g) => Bifoldable (Product f g) where bifoldMap f g (Pair x y) = bifoldMap f g x `mappend` bifoldMap f g y {-# INLINE bifoldMap #-} instance (Bifoldable1 f, Bifoldable1 g) => Bifoldable1 (Product f g) where bifoldMap1 f g (Pair x y) = bifoldMap1 f g x S.<> bifoldMap1 f g y {-# INLINE bifoldMap1 #-} instance (Bitraversable f, Bitraversable g) => Bitraversable (Product f g) where bitraverse f g (Pair x y) = Pair <$> bitraverse f g x <*> bitraverse f g y {-# INLINE bitraverse #-} instance BifunctorFunctor (Product p) where bifmap f (Pair p q) = Pair p (f q) instance BifunctorComonad (Product p) where biextract (Pair _ q) = q biduplicate pq@(Pair p _) = Pair p pq biextend f pq@(Pair p _) = Pair p (f pq) instance (Category p, Category q) => Category (Product p q) where id = Pair id id Pair x y . Pair x' y' = Pair (x . x') (y . y') instance (A.Arrow p, A.Arrow q) => A.Arrow (Product p q) where arr f = Pair (A.arr f) (A.arr f) first (Pair x y) = Pair (A.first x) (A.first y) second (Pair x y) = Pair (A.second x) (A.second y) Pair x y *** Pair x' y' = Pair (x A.*** x') (y A.*** y') Pair x y &&& Pair x' y' = Pair (x A.&&& x') (y A.&&& y') instance (A.ArrowChoice p, A.ArrowChoice q) => A.ArrowChoice (Product p q) where left (Pair x y) = Pair (A.left x) (A.left y) right (Pair x y) = Pair (A.right x) (A.right y) Pair x y +++ Pair x' y' = Pair (x A.+++ x') (y A.+++ y') Pair x y ||| Pair x' y' = Pair (x A.||| x') (y A.||| y') instance (A.ArrowLoop p, A.ArrowLoop q) => A.ArrowLoop (Product p q) where loop (Pair x y) = Pair (A.loop x) (A.loop y) instance (A.ArrowZero p, A.ArrowZero q) => A.ArrowZero (Product p q) where zeroArrow = Pair A.zeroArrow A.zeroArrow instance (A.ArrowPlus p, A.ArrowPlus q) => A.ArrowPlus (Product p q) where Pair x y <+> Pair x' y' = Pair (x A.<+> x') (y A.<+> y') -- | @since 5.6.1 instance (Swap p, Swap q) => Swap (Product p q) where swap (Pair p q) = Pair (swap p) (swap q) bifunctors-5.6.2/src/Data/Bifunctor/Sum.hs0000644000000000000000000000621407346545000016571 0ustar0000000000000000{-# LANGUAGE DeriveFoldable #-} {-# LANGUAGE DeriveFunctor #-} {-# LANGUAGE DeriveGeneric #-} {-# LANGUAGE DeriveTraversable #-} {-# LANGUAGE EmptyDataDecls #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE PolyKinds #-} {-# LANGUAGE Safe #-} {-# LANGUAGE StandaloneDeriving #-} {-# LANGUAGE TypeFamilies #-} module Data.Bifunctor.Sum where import Data.Bifunctor import Data.Bifunctor.Functor import Data.Bifunctor.Swap (Swap (..)) import Data.Bifoldable import Data.Bitraversable import Data.Functor.Classes import GHC.Generics data Sum p q a b = L2 (p a b) | R2 (q a b) deriving (Eq, Ord, Show, Read, Generic, Generic1) deriving instance (Functor (f a), Functor (g a)) => Functor (Sum f g a) deriving instance (Foldable (f a), Foldable (g a)) => Foldable (Sum f g a) deriving instance (Traversable (f a), Traversable (g a)) => Traversable (Sum f g a) instance (Eq2 f, Eq2 g, Eq a) => Eq1 (Sum f g a) where liftEq = liftEq2 (==) instance (Eq2 f, Eq2 g) => Eq2 (Sum f g) where liftEq2 f g (L2 x1) (L2 x2) = liftEq2 f g x1 x2 liftEq2 _ _ (L2 _) (R2 _) = False liftEq2 _ _ (R2 _) (L2 _) = False liftEq2 f g (R2 y1) (R2 y2) = liftEq2 f g y1 y2 instance (Ord2 f, Ord2 g, Ord a) => Ord1 (Sum f g a) where liftCompare = liftCompare2 compare instance (Ord2 f, Ord2 g) => Ord2 (Sum f g) where liftCompare2 f g (L2 x1) (L2 x2) = liftCompare2 f g x1 x2 liftCompare2 _ _ (L2 _) (R2 _) = LT liftCompare2 _ _ (R2 _) (L2 _) = GT liftCompare2 f g (R2 y1) (R2 y2) = liftCompare2 f g y1 y2 instance (Read2 f, Read2 g, Read a) => Read1 (Sum f g a) where liftReadsPrec = liftReadsPrec2 readsPrec readList instance (Read2 f, Read2 g) => Read2 (Sum f g) where liftReadsPrec2 rp1 rl1 rp2 rl2 = readsData $ readsUnaryWith (liftReadsPrec2 rp1 rl1 rp2 rl2) "L2" L2 `mappend` readsUnaryWith (liftReadsPrec2 rp1 rl1 rp2 rl2) "R2" R2 instance (Show2 f, Show2 g, Show a) => Show1 (Sum f g a) where liftShowsPrec = liftShowsPrec2 showsPrec showList instance (Show2 f, Show2 g) => Show2 (Sum f g) where liftShowsPrec2 sp1 sl1 sp2 sl2 p (L2 x) = showsUnaryWith (liftShowsPrec2 sp1 sl1 sp2 sl2) "L2" p x liftShowsPrec2 sp1 sl1 sp2 sl2 p (R2 y) = showsUnaryWith (liftShowsPrec2 sp1 sl1 sp2 sl2) "R2" p y instance (Bifunctor p, Bifunctor q) => Bifunctor (Sum p q) where bimap f g (L2 p) = L2 (bimap f g p) bimap f g (R2 q) = R2 (bimap f g q) first f (L2 p) = L2 (first f p) first f (R2 q) = R2 (first f q) second f (L2 p) = L2 (second f p) second f (R2 q) = R2 (second f q) instance (Bifoldable p, Bifoldable q) => Bifoldable (Sum p q) where bifoldMap f g (L2 p) = bifoldMap f g p bifoldMap f g (R2 q) = bifoldMap f g q instance (Bitraversable p, Bitraversable q) => Bitraversable (Sum p q) where bitraverse f g (L2 p) = L2 <$> bitraverse f g p bitraverse f g (R2 q) = R2 <$> bitraverse f g q instance BifunctorFunctor (Sum p) where bifmap _ (L2 p) = L2 p bifmap f (R2 q) = R2 (f q) instance BifunctorMonad (Sum p) where bireturn = R2 bijoin (L2 p) = L2 p bijoin (R2 q) = q bibind _ (L2 p) = L2 p bibind f (R2 q) = f q -- | @since 5.6.1 instance (Swap p, Swap q) => Swap (Sum p q) where swap (L2 p) = L2 (swap p) swap (R2 q) = R2 (swap q) bifunctors-5.6.2/src/Data/Bifunctor/TH.hs0000644000000000000000000014767007346545000016354 0ustar0000000000000000{-# LANGUAGE CPP #-} {-# LANGUAGE BangPatterns #-} {-# LANGUAGE PatternGuards #-} {-# LANGUAGE ScopedTypeVariables #-} {-# LANGUAGE Unsafe #-} ----------------------------------------------------------------------------- -- | -- Copyright : (C) 2008-2016 Edward Kmett, (C) 2015-2016 Ryan Scott -- License : BSD-style (see the file LICENSE) -- -- Maintainer : Edward Kmett -- Stability : provisional -- Portability : portable -- -- Functions to mechanically derive 'Bifunctor', 'Bifoldable', -- or 'Bitraversable' instances, or to splice their functions directly into -- source code. You need to enable the @TemplateHaskell@ language extension -- in order to use this module. ---------------------------------------------------------------------------- module Data.Bifunctor.TH ( -- * @derive@- functions -- $derive -- * @make@- functions -- $make -- * 'Bifunctor' deriveBifunctor , deriveBifunctorOptions , makeBimap , makeBimapOptions -- * 'Bifoldable' , deriveBifoldable , deriveBifoldableOptions , makeBifold , makeBifoldOptions , makeBifoldMap , makeBifoldMapOptions , makeBifoldr , makeBifoldrOptions , makeBifoldl , makeBifoldlOptions -- * 'Bitraversable' , deriveBitraversable , deriveBitraversableOptions , makeBitraverse , makeBitraverseOptions , makeBisequenceA , makeBisequenceAOptions , makeBimapM , makeBimapMOptions , makeBisequence , makeBisequenceOptions -- * 'Options' , Options(..) , defaultOptions ) where import Control.Monad (guard, unless, when) import Data.Bifunctor.TH.Internal import qualified Data.List as List import qualified Data.Map as Map ((!), fromList, keys, lookup, member, size) import Data.Maybe import Language.Haskell.TH.Datatype as Datatype import Language.Haskell.TH.Datatype.TyVarBndr import Language.Haskell.TH.Lib import Language.Haskell.TH.Ppr import Language.Haskell.TH.Syntax ------------------------------------------------------------------------------- -- User-facing API ------------------------------------------------------------------------------- -- | Options that further configure how the functions in "Data.Bifunctor.TH" -- should behave. newtype Options = Options { emptyCaseBehavior :: Bool -- ^ If 'True', derived instances for empty data types (i.e., ones with -- no data constructors) will use the @EmptyCase@ language extension. -- If 'False', derived instances will simply use 'seq' instead. } deriving (Eq, Ord, Read, Show) -- | Conservative 'Options' that doesn't attempt to use @EmptyCase@ (to -- prevent users from having to enable that extension at use sites.) defaultOptions :: Options defaultOptions = Options { emptyCaseBehavior = False } {- $derive 'deriveBifunctor', 'deriveBifoldable', and 'deriveBitraversable' automatically generate their respective class instances for a given data type, newtype, or data family instance that has at least two type variable. Examples: @ {-# LANGUAGE TemplateHaskell #-} import Data.Bifunctor.TH data Pair a b = Pair a b $('deriveBifunctor' ''Pair) -- instance Bifunctor Pair where ... data WrapLeftPair f g a b = WrapLeftPair (f a) (g a b) $('deriveBifoldable' ''WrapLeftPair) -- instance (Foldable f, Bifoldable g) => Bifoldable (WrapLeftPair f g) where ... @ If you are using @template-haskell-2.7.0.0@ or later (i.e., GHC 7.4 or later), the @derive@ functions can be used data family instances (which requires the @-XTypeFamilies@ extension). To do so, pass the name of a data or newtype instance constructor (NOT a data family name!) to a @derive@ function. Note that the generated code may require the @-XFlexibleInstances@ extension. Example: @ {-# LANGUAGE FlexibleInstances, TemplateHaskell, TypeFamilies #-} import Data.Bifunctor.TH class AssocClass a b c where data AssocData a b c instance AssocClass Int b c where data AssocData Int b c = AssocDataInt1 Int | AssocDataInt2 b c $('deriveBitraversable' 'AssocDataInt1) -- instance Bitraversable (AssocData Int) where ... -- Alternatively, one could use $(deriveBitraversable 'AssocDataInt2) @ Note that there are some limitations: * The 'Name' argument to a @derive@ function must not be a type synonym. * With a @derive@ function, the last two type variables must both be of kind @*@. Other type variables of kind @* -> *@ are assumed to require a 'Functor', 'Foldable', or 'Traversable' constraint (depending on which @derive@ function is used), and other type variables of kind @* -> * -> *@ are assumed to require an 'Bifunctor', 'Bifoldable', or 'Bitraversable' constraint. If your data type doesn't meet these assumptions, use a @make@ function. * If using the @-XDatatypeContexts@, @-XExistentialQuantification@, or @-XGADTs@ extensions, a constraint cannot mention either of the last two type variables. For example, @data Illegal2 a b where I2 :: Ord a => a -> b -> Illegal2 a b@ cannot have a derived 'Bifunctor' instance. * If either of the last two type variables is used within a constructor argument's type, it must only be used in the last two type arguments. For example, @data Legal a b = Legal (Int, Int, a, b)@ can have a derived 'Bifunctor' instance, but @data Illegal a b = Illegal (a, b, a, b)@ cannot. * Data family instances must be able to eta-reduce the last two type variables. In other words, if you have a instance of the form: @ data family Family a1 ... an t1 t2 data instance Family e1 ... e2 v1 v2 = ... @ Then the following conditions must hold: 1. @v1@ and @v2@ must be distinct type variables. 2. Neither @v1@ not @v2@ must be mentioned in any of @e1@, ..., @e2@. -} {- $make There may be scenarios in which you want to, say, 'bimap' over an arbitrary data type or data family instance without having to make the type an instance of 'Bifunctor'. For these cases, this module provides several functions (all prefixed with @make@-) that splice the appropriate lambda expression into your source code. This is particularly useful for creating instances for sophisticated data types. For example, 'deriveBifunctor' cannot infer the correct type context for @newtype HigherKinded f a b c = HigherKinded (f a b c)@, since @f@ is of kind @* -> * -> * -> *@. However, it is still possible to create a 'Bifunctor' instance for @HigherKinded@ without too much trouble using 'makeBimap': @ {-# LANGUAGE FlexibleContexts, TemplateHaskell #-} import Data.Bifunctor import Data.Bifunctor.TH newtype HigherKinded f a b c = HigherKinded (f a b c) instance Bifunctor (f a) => Bifunctor (HigherKinded f a) where bimap = $(makeBimap ''HigherKinded) @ -} -- | Generates a 'Bifunctor' instance declaration for the given data type or data -- family instance. deriveBifunctor :: Name -> Q [Dec] deriveBifunctor = deriveBifunctorOptions defaultOptions -- | Like 'deriveBifunctor', but takes an 'Options' argument. deriveBifunctorOptions :: Options -> Name -> Q [Dec] deriveBifunctorOptions = deriveBiClass Bifunctor -- | Generates a lambda expression which behaves like 'bimap' (without requiring a -- 'Bifunctor' instance). makeBimap :: Name -> Q Exp makeBimap = makeBimapOptions defaultOptions -- | Like 'makeBimap', but takes an 'Options' argument. makeBimapOptions :: Options -> Name -> Q Exp makeBimapOptions = makeBiFun Bimap -- | Generates a 'Bifoldable' instance declaration for the given data type or data -- family instance. deriveBifoldable :: Name -> Q [Dec] deriveBifoldable = deriveBifoldableOptions defaultOptions -- | Like 'deriveBifoldable', but takes an 'Options' argument. deriveBifoldableOptions :: Options -> Name -> Q [Dec] deriveBifoldableOptions = deriveBiClass Bifoldable --- | Generates a lambda expression which behaves like 'bifold' (without requiring a -- 'Bifoldable' instance). makeBifold :: Name -> Q Exp makeBifold = makeBifoldOptions defaultOptions -- | Like 'makeBifold', but takes an 'Options' argument. makeBifoldOptions :: Options -> Name -> Q Exp makeBifoldOptions opts name = appsE [ makeBifoldMapOptions opts name , varE idValName , varE idValName ] -- | Generates a lambda expression which behaves like 'bifoldMap' (without requiring -- a 'Bifoldable' instance). makeBifoldMap :: Name -> Q Exp makeBifoldMap = makeBifoldMapOptions defaultOptions -- | Like 'makeBifoldMap', but takes an 'Options' argument. makeBifoldMapOptions :: Options -> Name -> Q Exp makeBifoldMapOptions = makeBiFun BifoldMap -- | Generates a lambda expression which behaves like 'bifoldr' (without requiring a -- 'Bifoldable' instance). makeBifoldr :: Name -> Q Exp makeBifoldr = makeBifoldrOptions defaultOptions -- | Like 'makeBifoldr', but takes an 'Options' argument. makeBifoldrOptions :: Options -> Name -> Q Exp makeBifoldrOptions = makeBiFun Bifoldr -- | Generates a lambda expression which behaves like 'bifoldl' (without requiring a -- 'Bifoldable' instance). makeBifoldl :: Name -> Q Exp makeBifoldl = makeBifoldlOptions defaultOptions -- | Like 'makeBifoldl', but takes an 'Options' argument. makeBifoldlOptions :: Options -> Name -> Q Exp makeBifoldlOptions opts name = do f <- newName "f" g <- newName "g" z <- newName "z" t <- newName "t" lamE [varP f, varP g, varP z, varP t] $ appsE [ varE appEndoValName , appsE [ varE getDualValName , appsE [ makeBifoldMapOptions opts name , foldFun f , foldFun g , varE t] ] , varE z ] where foldFun :: Name -> Q Exp foldFun n = infixApp (conE dualDataName) (varE composeValName) (infixApp (conE endoDataName) (varE composeValName) (varE flipValName `appE` varE n) ) -- | Generates a 'Bitraversable' instance declaration for the given data type or data -- family instance. deriveBitraversable :: Name -> Q [Dec] deriveBitraversable = deriveBitraversableOptions defaultOptions -- | Like 'deriveBitraversable', but takes an 'Options' argument. deriveBitraversableOptions :: Options -> Name -> Q [Dec] deriveBitraversableOptions = deriveBiClass Bitraversable -- | Generates a lambda expression which behaves like 'bitraverse' (without -- requiring a 'Bitraversable' instance). makeBitraverse :: Name -> Q Exp makeBitraverse = makeBitraverseOptions defaultOptions -- | Like 'makeBitraverse', but takes an 'Options' argument. makeBitraverseOptions :: Options -> Name -> Q Exp makeBitraverseOptions = makeBiFun Bitraverse -- | Generates a lambda expression which behaves like 'bisequenceA' (without -- requiring a 'Bitraversable' instance). makeBisequenceA :: Name -> Q Exp makeBisequenceA = makeBisequenceAOptions defaultOptions -- | Like 'makeBitraverseA', but takes an 'Options' argument. makeBisequenceAOptions :: Options -> Name -> Q Exp makeBisequenceAOptions opts name = appsE [ makeBitraverseOptions opts name , varE idValName , varE idValName ] -- | Generates a lambda expression which behaves like 'bimapM' (without -- requiring a 'Bitraversable' instance). makeBimapM :: Name -> Q Exp makeBimapM = makeBimapMOptions defaultOptions -- | Like 'makeBimapM', but takes an 'Options' argument. makeBimapMOptions :: Options -> Name -> Q Exp makeBimapMOptions opts name = do f <- newName "f" g <- newName "g" lamE [varP f, varP g] . infixApp (varE unwrapMonadValName) (varE composeValName) $ appsE [ makeBitraverseOptions opts name , wrapMonadExp f , wrapMonadExp g ] where wrapMonadExp :: Name -> Q Exp wrapMonadExp n = infixApp (conE wrapMonadDataName) (varE composeValName) (varE n) -- | Generates a lambda expression which behaves like 'bisequence' (without -- requiring a 'Bitraversable' instance). makeBisequence :: Name -> Q Exp makeBisequence = makeBisequenceOptions defaultOptions -- | Like 'makeBisequence', but takes an 'Options' argument. makeBisequenceOptions :: Options -> Name -> Q Exp makeBisequenceOptions opts name = appsE [ makeBimapMOptions opts name , varE idValName , varE idValName ] ------------------------------------------------------------------------------- -- Code generation ------------------------------------------------------------------------------- -- | Derive a class instance declaration (depending on the BiClass argument's value). deriveBiClass :: BiClass -> Options -> Name -> Q [Dec] deriveBiClass biClass opts name = do info <- reifyDatatype name case info of DatatypeInfo { datatypeContext = ctxt , datatypeName = parentName , datatypeInstTypes = instTys , datatypeVariant = variant , datatypeCons = cons } -> do (instanceCxt, instanceType) <- buildTypeInstance biClass parentName ctxt instTys variant (:[]) `fmap` instanceD (return instanceCxt) (return instanceType) (biFunDecs biClass opts parentName instTys cons) -- | Generates a declaration defining the primary function(s) corresponding to a -- particular class (bimap for Bifunctor, bifoldr and bifoldMap for Bifoldable, and -- bitraverse for Bitraversable). -- -- For why both bifoldr and bifoldMap are derived for Bifoldable, see Trac #7436. biFunDecs :: BiClass -> Options -> Name -> [Type] -> [ConstructorInfo] -> [Q Dec] biFunDecs biClass opts parentName instTys cons = map makeFunD $ biClassToFuns biClass where makeFunD :: BiFun -> Q Dec makeFunD biFun = funD (biFunName biFun) [ clause [] (normalB $ makeBiFunForCons biFun opts parentName instTys cons) [] ] -- | Generates a lambda expression which behaves like the BiFun argument. makeBiFun :: BiFun -> Options -> Name -> Q Exp makeBiFun biFun opts name = do info <- reifyDatatype name case info of DatatypeInfo { datatypeContext = ctxt , datatypeName = parentName , datatypeInstTypes = instTys , datatypeVariant = variant , datatypeCons = cons } -> -- We force buildTypeInstance here since it performs some checks for whether -- or not the provided datatype can actually have bimap/bifoldr/bitraverse/etc. -- implemented for it, and produces errors if it can't. buildTypeInstance (biFunToClass biFun) parentName ctxt instTys variant >> makeBiFunForCons biFun opts parentName instTys cons -- | Generates a lambda expression for the given constructors. -- All constructors must be from the same type. makeBiFunForCons :: BiFun -> Options -> Name -> [Type] -> [ConstructorInfo] -> Q Exp makeBiFunForCons biFun opts _parentName instTys cons = do map1 <- newName "f" map2 <- newName "g" z <- newName "z" -- Only used for deriving bifoldr value <- newName "value" let argNames = catMaybes [ Just map1 , Just map2 , guard (biFun == Bifoldr) >> Just z , Just value ] lastTyVars = map varTToName $ drop (length instTys - 2) instTys tvMap = Map.fromList $ zip lastTyVars [map1, map2] lamE (map varP argNames) . appsE $ [ varE $ biFunConstName biFun , makeFun z value tvMap ] ++ map varE argNames where makeFun :: Name -> Name -> TyVarMap -> Q Exp makeFun z value tvMap = do roles <- reifyRoles _parentName case () of _ | Just (rs, PhantomR) <- unsnoc roles , Just (_, PhantomR) <- unsnoc rs -> biFunPhantom z value | null cons && emptyCaseBehavior opts -> biFunEmptyCase biFun z value | null cons -> biFunNoCons biFun z value | otherwise -> caseE (varE value) (map (makeBiFunForCon biFun z tvMap) cons) biFunPhantom :: Name -> Name -> Q Exp biFunPhantom z value = biFunTrivial coerce (varE pureValName `appE` coerce) biFun z where coerce :: Q Exp coerce = varE coerceValName `appE` varE value -- | Generates a match for a single constructor. makeBiFunForCon :: BiFun -> Name -> TyVarMap -> ConstructorInfo -> Q Match makeBiFunForCon biFun z tvMap con@(ConstructorInfo { constructorName = conName , constructorContext = ctxt }) = do when ((any (`predMentionsName` Map.keys tvMap) ctxt || Map.size tvMap < 2) && not (allowExQuant (biFunToClass biFun))) $ existentialContextError conName case biFun of Bimap -> makeBimapMatch tvMap con Bifoldr -> makeBifoldrMatch z tvMap con BifoldMap -> makeBifoldMapMatch tvMap con Bitraverse -> makeBitraverseMatch tvMap con -- | Generates a match whose right-hand side implements @bimap@. makeBimapMatch :: TyVarMap -> ConstructorInfo -> Q Match makeBimapMatch tvMap con@(ConstructorInfo{constructorName = conName}) = do parts <- foldDataConArgs tvMap ft_bimap con match_for_con conName parts where ft_bimap :: FFoldType (Exp -> Q Exp) ft_bimap = FT { ft_triv = return , ft_var = \v x -> return $ VarE (tvMap Map.! v) `AppE` x , ft_fun = \g h x -> mkSimpleLam $ \b -> do gg <- g b h $ x `AppE` gg , ft_tup = mkSimpleTupleCase match_for_con , ft_ty_app = \argGs x -> do let inspect :: (Type, Exp -> Q Exp) -> Q Exp inspect (argTy, g) -- If the argument type is a bare occurrence of one -- of the data type's last type variables, then we -- can generate more efficient code. -- This was inspired by GHC#17880. | Just argVar <- varTToName_maybe argTy , Just f <- Map.lookup argVar tvMap = return $ VarE f | otherwise = mkSimpleLam g appsE $ varE (fmapArity (length argGs)) : map inspect argGs ++ [return x] , ft_forall = \_ g x -> g x , ft_bad_app = \_ -> outOfPlaceTyVarError conName , ft_co_var = \_ _ -> contravarianceError conName } -- Con a1 a2 ... -> Con (f1 a1) (f2 a2) ... match_for_con :: Name -> [Exp -> Q Exp] -> Q Match match_for_con = mkSimpleConMatch $ \conName' xs -> appsE (conE conName':xs) -- Con x1 x2 .. -- | Generates a match whose right-hand side implements @bifoldr@. makeBifoldrMatch :: Name -> TyVarMap -> ConstructorInfo -> Q Match makeBifoldrMatch z tvMap con@(ConstructorInfo{constructorName = conName}) = do parts <- foldDataConArgs tvMap ft_bifoldr con parts' <- sequence parts match_for_con (VarE z) conName parts' where -- The Bool is True if the type mentions of the last two type parameters, -- False otherwise. Later, match_for_con uses mkSimpleConMatch2 to filter -- out expressions that do not mention the last parameters by checking for -- False. ft_bifoldr :: FFoldType (Q (Bool, Exp)) ft_bifoldr = FT { -- See Note [ft_triv for Bifoldable and Bitraversable] ft_triv = do lam <- mkSimpleLam2 $ \_ z' -> return z' return (False, lam) , ft_var = \v -> return (True, VarE $ tvMap Map.! v) , ft_tup = \t gs -> do gg <- sequence gs lam <- mkSimpleLam2 $ \x z' -> mkSimpleTupleCase (match_for_con z') t gg x return (True, lam) , ft_ty_app = \gs -> do lam <- mkSimpleLam2 $ \x z' -> appsE $ varE (foldrArity (length gs)) : map (\(_, hs) -> fmap snd hs) gs ++ map return [z', x] return (True, lam) , ft_forall = \_ g -> g , ft_co_var = \_ -> contravarianceError conName , ft_fun = \_ _ -> noFunctionsError conName , ft_bad_app = outOfPlaceTyVarError conName } match_for_con :: Exp -> Name -> [(Bool, Exp)] -> Q Match match_for_con zExp = mkSimpleConMatch2 $ \_ xs -> return $ mkBifoldr xs where -- g1 v1 (g2 v2 (.. z)) mkBifoldr :: [Exp] -> Exp mkBifoldr = foldr AppE zExp -- | Generates a match whose right-hand side implements @bifoldMap@. makeBifoldMapMatch :: TyVarMap -> ConstructorInfo -> Q Match makeBifoldMapMatch tvMap con@(ConstructorInfo{constructorName = conName}) = do parts <- foldDataConArgs tvMap ft_bifoldMap con parts' <- sequence parts match_for_con conName parts' where -- The Bool is True if the type mentions of the last two type parameters, -- False otherwise. Later, match_for_con uses mkSimpleConMatch2 to filter -- out expressions that do not mention the last parameters by checking for -- False. ft_bifoldMap :: FFoldType (Q (Bool, Exp)) ft_bifoldMap = FT { -- See Note [ft_triv for Bifoldable and Bitraversable] ft_triv = do lam <- mkSimpleLam $ \_ -> return $ VarE memptyValName return (False, lam) , ft_var = \v -> return (True, VarE $ tvMap Map.! v) , ft_tup = \t gs -> do gg <- sequence gs lam <- mkSimpleLam $ mkSimpleTupleCase match_for_con t gg return (True, lam) , ft_ty_app = \gs -> do e <- appsE $ varE (foldMapArity (length gs)) : map (\(_, hs) -> fmap snd hs) gs return (True, e) , ft_forall = \_ g -> g , ft_co_var = \_ -> contravarianceError conName , ft_fun = \_ _ -> noFunctionsError conName , ft_bad_app = outOfPlaceTyVarError conName } match_for_con :: Name -> [(Bool, Exp)] -> Q Match match_for_con = mkSimpleConMatch2 $ \_ xs -> return $ mkBifoldMap xs where -- mappend v1 (mappend v2 ..) mkBifoldMap :: [Exp] -> Exp mkBifoldMap [] = VarE memptyValName mkBifoldMap es = foldr1 (AppE . AppE (VarE mappendValName)) es -- | Generates a match whose right-hand side implements @bitraverse@. makeBitraverseMatch :: TyVarMap -> ConstructorInfo -> Q Match makeBitraverseMatch tvMap con@(ConstructorInfo{constructorName = conName}) = do parts <- foldDataConArgs tvMap ft_bitrav con parts' <- sequence parts match_for_con conName parts' where -- The Bool is True if the type mentions of the last two type parameters, -- False otherwise. Later, match_for_con uses mkSimpleConMatch2 to filter -- out expressions that do not mention the last parameters by checking for -- False. ft_bitrav :: FFoldType (Q (Bool, Exp)) ft_bitrav = FT { -- See Note [ft_triv for Bifoldable and Bitraversable] ft_triv = return (False, VarE pureValName) , ft_var = \v -> return (True, VarE $ tvMap Map.! v) , ft_tup = \t gs -> do gg <- sequence gs lam <- mkSimpleLam $ mkSimpleTupleCase match_for_con t gg return (True, lam) , ft_ty_app = \gs -> do e <- appsE $ varE (traverseArity (length gs)) : map (\(_, hs) -> fmap snd hs) gs return (True, e) , ft_forall = \_ g -> g , ft_co_var = \_ -> contravarianceError conName , ft_fun = \_ _ -> noFunctionsError conName , ft_bad_app = outOfPlaceTyVarError conName } -- Con a1 a2 ... -> liftA2 (\b1 b2 ... -> Con b1 b2 ...) (g1 a1) -- (g2 a2) <*> ... match_for_con :: Name -> [(Bool, Exp)] -> Q Match match_for_con = mkSimpleConMatch2 $ \conExp xs -> return $ mkApCon conExp xs where -- liftA2 (\b1 b2 ... -> Con b1 b2 ...) x1 x2 <*> .. mkApCon :: Exp -> [Exp] -> Exp mkApCon conExp [] = VarE pureValName `AppE` conExp mkApCon conExp [e] = VarE fmapValName `AppE` conExp `AppE` e mkApCon conExp (e1:e2:es) = List.foldl' appAp (VarE liftA2ValName `AppE` conExp `AppE` e1 `AppE` e2) es where appAp se1 se2 = InfixE (Just se1) (VarE apValName) (Just se2) ------------------------------------------------------------------------------- -- Template Haskell reifying and AST manipulation ------------------------------------------------------------------------------- -- For the given Types, generate an instance context and head. Coming up with -- the instance type isn't as simple as dropping the last types, as you need to -- be wary of kinds being instantiated with *. -- See Note [Type inference in derived instances] buildTypeInstance :: BiClass -- ^ Bifunctor, Bifoldable, or Bitraversable -> Name -- ^ The type constructor or data family name -> Cxt -- ^ The datatype context -> [Type] -- ^ The types to instantiate the instance with -> DatatypeVariant -- ^ Are we dealing with a data family instance or not -> Q (Cxt, Type) buildTypeInstance biClass tyConName dataCxt instTysOrig variant = do -- Make sure to expand through type/kind synonyms! Otherwise, the -- eta-reduction check might get tripped up over type variables in a -- synonym that are actually dropped. -- (See GHC Trac #11416 for a scenario where this actually happened.) varTysExp <- mapM resolveTypeSynonyms instTysOrig let remainingLength :: Int remainingLength = length instTysOrig - 2 droppedTysExp :: [Type] droppedTysExp = drop remainingLength varTysExp droppedStarKindStati :: [StarKindStatus] droppedStarKindStati = map canRealizeKindStar droppedTysExp -- Check there are enough types to drop and that all of them are either of -- kind * or kind k (for some kind variable k). If not, throw an error. when (remainingLength < 0 || any (== NotKindStar) droppedStarKindStati) $ derivingKindError biClass tyConName let droppedKindVarNames :: [Name] droppedKindVarNames = catKindVarNames droppedStarKindStati -- Substitute kind * for any dropped kind variables varTysExpSubst :: [Type] varTysExpSubst = map (substNamesWithKindStar droppedKindVarNames) varTysExp remainingTysExpSubst, droppedTysExpSubst :: [Type] (remainingTysExpSubst, droppedTysExpSubst) = splitAt remainingLength varTysExpSubst -- All of the type variables mentioned in the dropped types -- (post-synonym expansion) droppedTyVarNames :: [Name] droppedTyVarNames = freeVariables droppedTysExpSubst -- If any of the dropped types were polykinded, ensure that they are of kind * -- after substituting * for the dropped kind variables. If not, throw an error. unless (all hasKindStar droppedTysExpSubst) $ derivingKindError biClass tyConName let preds :: [Maybe Pred] kvNames :: [[Name]] kvNames' :: [Name] -- Derive instance constraints (and any kind variables which are specialized -- to * in those constraints) (preds, kvNames) = unzip $ map (deriveConstraint biClass) remainingTysExpSubst kvNames' = concat kvNames -- Substitute the kind variables specialized in the constraints with * remainingTysExpSubst' :: [Type] remainingTysExpSubst' = map (substNamesWithKindStar kvNames') remainingTysExpSubst -- We now substitute all of the specialized-to-* kind variable names with -- *, but in the original types, not the synonym-expanded types. The reason -- we do this is a superficial one: we want the derived instance to resemble -- the datatype written in source code as closely as possible. For example, -- for the following data family instance: -- -- data family Fam a -- newtype instance Fam String = Fam String -- -- We'd want to generate the instance: -- -- instance C (Fam String) -- -- Not: -- -- instance C (Fam [Char]) remainingTysOrigSubst :: [Type] remainingTysOrigSubst = map (substNamesWithKindStar (List.union droppedKindVarNames kvNames')) $ take remainingLength instTysOrig isDataFamily <- case variant of Datatype -> return False Newtype -> return False DataInstance -> return True NewtypeInstance -> return True #if MIN_VERSION_th_abstraction(0,5,0) Datatype.TypeData -> typeDataError tyConName #endif let remainingTysOrigSubst' :: [Type] -- See Note [Kind signatures in derived instances] for an explanation -- of the isDataFamily check. remainingTysOrigSubst' = if isDataFamily then remainingTysOrigSubst else map unSigT remainingTysOrigSubst instanceCxt :: Cxt instanceCxt = catMaybes preds instanceType :: Type instanceType = AppT (ConT $ biClassName biClass) $ applyTyCon tyConName remainingTysOrigSubst' -- If the datatype context mentions any of the dropped type variables, -- we can't derive an instance, so throw an error. when (any (`predMentionsName` droppedTyVarNames) dataCxt) $ datatypeContextError tyConName instanceType -- Also ensure the dropped types can be safely eta-reduced. Otherwise, -- throw an error. unless (canEtaReduce remainingTysExpSubst' droppedTysExpSubst) $ etaReductionError instanceType return (instanceCxt, instanceType) -- | Attempt to derive a constraint on a Type. If successful, return -- Just the constraint and any kind variable names constrained to *. -- Otherwise, return Nothing and the empty list. -- -- See Note [Type inference in derived instances] for the heuristics used to -- come up with constraints. deriveConstraint :: BiClass -> Type -> (Maybe Pred, [Name]) deriveConstraint biClass t | not (isTyVar t) = (Nothing, []) | otherwise = case hasKindVarChain 1 t of Just ns -> ((`applyClass` tName) `fmap` biClassConstraint biClass 1, ns) _ -> case hasKindVarChain 2 t of Just ns -> ((`applyClass` tName) `fmap` biClassConstraint biClass 2, ns) _ -> (Nothing, []) where tName :: Name tName = varTToName t {- Note [Kind signatures in derived instances] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ It is possible to put explicit kind signatures into the derived instances, e.g., instance C a => C (Data (f :: * -> *)) where ... But it is preferable to avoid this if possible. If we come up with an incorrect kind signature (which is entirely possible, since our type inferencer is pretty unsophisticated - see Note [Type inference in derived instances]), then GHC will flat-out reject the instance, which is quite unfortunate. Plain old datatypes have the advantage that you can avoid using any kind signatures at all in their instances. This is because a datatype declaration uses all type variables, so the types that we use in a derived instance uniquely determine their kinds. As long as we plug in the right types, the kind inferencer can do the rest of the work. For this reason, we use unSigT to remove all kind signatures before splicing in the instance context and head. Data family instances are trickier, since a data family can have two instances that are distinguished by kind alone, e.g., data family Fam (a :: k) data instance Fam (a :: * -> *) data instance Fam (a :: *) If we dropped the kind signatures for C (Fam a), then GHC will have no way of knowing which instance we are talking about. To avoid this scenario, we always include explicit kind signatures in data family instances. There is a chance that the inferred kind signatures will be incorrect, but if so, we can always fall back on the make- functions. Note [Type inference in derived instances] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Type inference is can be tricky to get right, and we want to avoid recreating the entirety of GHC's type inferencer in Template Haskell. For this reason, we will probably never come up with derived instance contexts that are as accurate as GHC's. But that doesn't mean we can't do anything! There are a couple of simple things we can do to make instance contexts that work for 80% of use cases: 1. If one of the last type parameters is polykinded, then its kind will be specialized to * in the derived instance. We note what kind variable the type parameter had and substitute it with * in the other types as well. For example, imagine you had data Data (a :: k) (b :: k) (c :: k) Then you'd want to derived instance to be: instance C (Data (a :: *)) Not: instance C (Data (a :: k)) 2. We naïvely come up with instance constraints using the following criteria: (i) If there's a type parameter n of kind k1 -> k2 (where k1/k2 are * or kind variables), then generate a Functor n constraint, and if k1/k2 are kind variables, then substitute k1/k2 with * elsewhere in the types. We must consider the case where they are kind variables because you might have a scenario like this: newtype Compose (f :: k3 -> *) (g :: k1 -> k2 -> k3) (a :: k1) (b :: k2) = Compose (f (g a b)) Which would have a derived Bifunctor instance of: instance (Functor f, Bifunctor g) => Bifunctor (Compose f g) where ... (ii) If there's a type parameter n of kind k1 -> k2 -> k3 (where k1/k2/k3 are * or kind variables), then generate a Bifunctor n constraint and perform kind substitution as in the other case. -} {- Note [Matching functions with GADT type variables] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ When deriving Bifoldable, there is a tricky corner case to consider: data Both a b where BothCon :: x -> x -> Both x x Which fold functions should be applied to which arguments of BothCon? We have a choice, since both the function of type (a -> m) and of type (b -> m) can be applied to either argument. In such a scenario, the second fold function takes precedence over the first fold function, so the derived Bifoldable instance would be: instance Bifoldable Both where bifoldMap _ g (BothCon x1 x2) = g x1 <> g x2 This is not an arbitrary choice, as this definition ensures that bifoldMap id = Foldable.foldMap for a derived Bifoldable instance for Both. -} ------------------------------------------------------------------------------- -- Error messages ------------------------------------------------------------------------------- -- | Either the given data type doesn't have enough type variables, or one of -- the type variables to be eta-reduced cannot realize kind *. derivingKindError :: BiClass -> Name -> Q a derivingKindError biClass tyConName = fail . showString "Cannot derive well-kinded instance of form ‘" . showString className . showChar ' ' . showParen True ( showString (nameBase tyConName) . showString " ..." ) . showString "‘\n\tClass " . showString className . showString " expects an argument of kind * -> * -> *" $ "" where className :: String className = nameBase $ biClassName biClass -- | One of the last two type variables appeared in a contravariant position -- when deriving Bifoldable or Bitraversable. contravarianceError :: Name -> Q a contravarianceError conName = fail . showString "Constructor ‘" . showString (nameBase conName) . showString "‘ must not use the last type variable(s) in a function argument" $ "" -- | A constructor has a function argument in a derived Bifoldable or Bitraversable -- instance. noFunctionsError :: Name -> Q a noFunctionsError conName = fail . showString "Constructor ‘" . showString (nameBase conName) . showString "‘ must not contain function types" $ "" -- | The data type has a DatatypeContext which mentions one of the eta-reduced -- type variables. datatypeContextError :: Name -> Type -> Q a datatypeContextError dataName instanceType = fail . showString "Can't make a derived instance of ‘" . showString (pprint instanceType) . showString "‘:\n\tData type ‘" . showString (nameBase dataName) . showString "‘ must not have a class context involving the last type argument(s)" $ "" -- | The data type has an existential constraint which mentions one of the -- eta-reduced type variables. existentialContextError :: Name -> Q a existentialContextError conName = fail . showString "Constructor ‘" . showString (nameBase conName) . showString "‘ must be truly polymorphic in the last argument(s) of the data type" $ "" -- | The data type mentions one of the n eta-reduced type variables in a place other -- than the last nth positions of a data type in a constructor's field. outOfPlaceTyVarError :: Name -> Q a outOfPlaceTyVarError conName = fail . showString "Constructor ‘" . showString (nameBase conName) . showString "‘ must only use its last two type variable(s) within" . showString " the last two argument(s) of a data type" $ "" -- | One of the last type variables cannot be eta-reduced (see the canEtaReduce -- function for the criteria it would have to meet). etaReductionError :: Type -> Q a etaReductionError instanceType = fail $ "Cannot eta-reduce to an instance of form \n\tinstance (...) => " ++ pprint instanceType typeDataError :: Name -> Q a typeDataError dataName = fail . showString "Cannot derive instance for ‘" . showString (nameBase dataName) . showString "‘, which is a ‘type data‘ declaration" $ "" ------------------------------------------------------------------------------- -- Class-specific constants ------------------------------------------------------------------------------- -- | A representation of which class is being derived. data BiClass = Bifunctor | Bifoldable | Bitraversable -- | A representation of which function is being generated. data BiFun = Bimap | Bifoldr | BifoldMap | Bitraverse deriving Eq biFunConstName :: BiFun -> Name biFunConstName Bimap = bimapConstValName biFunConstName Bifoldr = bifoldrConstValName biFunConstName BifoldMap = bifoldMapConstValName biFunConstName Bitraverse = bitraverseConstValName biClassName :: BiClass -> Name biClassName Bifunctor = bifunctorTypeName biClassName Bifoldable = bifoldableTypeName biClassName Bitraversable = bitraversableTypeName biFunName :: BiFun -> Name biFunName Bimap = bimapValName biFunName Bifoldr = bifoldrValName biFunName BifoldMap = bifoldMapValName biFunName Bitraverse = bitraverseValName biClassToFuns :: BiClass -> [BiFun] biClassToFuns Bifunctor = [Bimap] biClassToFuns Bifoldable = [Bifoldr, BifoldMap] biClassToFuns Bitraversable = [Bitraverse] biFunToClass :: BiFun -> BiClass biFunToClass Bimap = Bifunctor biFunToClass Bifoldr = Bifoldable biFunToClass BifoldMap = Bifoldable biFunToClass Bitraverse = Bitraversable biClassConstraint :: BiClass -> Int -> Maybe Name biClassConstraint Bifunctor 1 = Just functorTypeName biClassConstraint Bifoldable 1 = Just foldableTypeName biClassConstraint Bitraversable 1 = Just traversableTypeName biClassConstraint biClass 2 = Just $ biClassName biClass biClassConstraint _ _ = Nothing fmapArity :: Int -> Name fmapArity 1 = fmapValName fmapArity 2 = bimapValName fmapArity n = arityErr n foldrArity :: Int -> Name foldrArity 1 = foldrValName foldrArity 2 = bifoldrValName foldrArity n = arityErr n foldMapArity :: Int -> Name foldMapArity 1 = foldMapValName foldMapArity 2 = bifoldMapValName foldMapArity n = arityErr n traverseArity :: Int -> Name traverseArity 1 = traverseValName traverseArity 2 = bitraverseValName traverseArity n = arityErr n arityErr :: Int -> a arityErr n = error $ "Unsupported arity: " ++ show n allowExQuant :: BiClass -> Bool allowExQuant Bifoldable = True allowExQuant _ = False biFunEmptyCase :: BiFun -> Name -> Name -> Q Exp biFunEmptyCase biFun z value = biFunTrivial emptyCase (varE pureValName `appE` emptyCase) biFun z where emptyCase :: Q Exp emptyCase = caseE (varE value) [] biFunNoCons :: BiFun -> Name -> Name -> Q Exp biFunNoCons biFun z value = biFunTrivial seqAndError (varE pureValName `appE` seqAndError) biFun z where seqAndError :: Q Exp seqAndError = appE (varE seqValName) (varE value) `appE` appE (varE errorValName) (stringE $ "Void " ++ nameBase (biFunName biFun)) biFunTrivial :: Q Exp -> Q Exp -> BiFun -> Name -> Q Exp biFunTrivial bimapE bitraverseE biFun z = go biFun where go :: BiFun -> Q Exp go Bimap = bimapE go Bifoldr = varE z go BifoldMap = varE memptyValName go Bitraverse = bitraverseE {- Note [ft_triv for Bifoldable and Bitraversable] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ When deriving Bifoldable and Bitraversable, we filter out any subexpressions whose type does not mention one of the last two type parameters. From this, you might think that we don't need to implement ft_triv for bifoldr, bifoldMap, or bitraverse at all, but in fact we do need to. Imagine the following data type: data T a b = MkT a (T Int b) In a derived Bifoldable T instance, you would generate the following bifoldMap definition: bifoldMap f g (MkT a1 a2) = f a1 <> bifoldMap (\_ -> mempty) g arg2 You need to fill in bi_triv (\_ -> mempty) as the first argument to the recursive call to bifoldMap, since that is how the algorithm handles polymorphic recursion. -} ------------------------------------------------------------------------------- -- Generic traversal for functor-like deriving ------------------------------------------------------------------------------- -- Much of the code below is cargo-culted from the TcGenFunctor module in GHC. data FFoldType a -- Describes how to fold over a Type in a functor like way = FT { ft_triv :: a -- ^ Does not contain variables , ft_var :: Name -> a -- ^ A bare variable , ft_co_var :: Name -> a -- ^ A bare variable, contravariantly , ft_fun :: a -> a -> a -- ^ Function type , ft_tup :: TupleSort -> [a] -> a -- ^ Tuple type. The [a] is the result of folding over the -- arguments of the tuple. , ft_ty_app :: [(Type, a)] -> a -- ^ Type app, variables only in last argument. The [(Type, a)] -- represents the last argument types. That is, they form the -- argument parts of @fun_ty arg_ty_1 ... arg_ty_n@. , ft_bad_app :: a -- ^ Type app, variable other than in last arguments , ft_forall :: [TyVarBndrSpec] -> a -> a -- ^ Forall type } -- Note that in GHC, this function is pure. It must be monadic here since we: -- -- (1) Expand type synonyms -- (2) Detect type family applications -- -- Which require reification in Template Haskell, but are pure in Core. functorLikeTraverse :: forall a. TyVarMap -- ^ Variables to look for -> FFoldType a -- ^ How to fold -> Type -- ^ Type to process -> Q a functorLikeTraverse tvMap (FT { ft_triv = caseTrivial, ft_var = caseVar , ft_co_var = caseCoVar, ft_fun = caseFun , ft_tup = caseTuple, ft_ty_app = caseTyApp , ft_bad_app = caseWrongArg, ft_forall = caseForAll }) ty = do ty' <- resolveTypeSynonyms ty (res, _) <- go False ty' return res where go :: Bool -- Covariant or contravariant context -> Type -> Q (a, Bool) -- (result of type a, does type contain var) go co t@AppT{} | (ArrowT, [funArg, funRes]) <- unapplyTy t = do (funArgR, funArgC) <- go (not co) funArg (funResR, funResC) <- go co funRes if funArgC || funResC then return (caseFun funArgR funResR, True) else trivial go co t@AppT{} = do let (f, args) = unapplyTy t (_, fc) <- go co f (xrs, xcs) <- fmap unzip $ mapM (go co) args let numLastArgs, numFirstArgs :: Int numLastArgs = min 2 $ length args numFirstArgs = length args - numLastArgs tuple :: TupleSort -> Q (a, Bool) tuple tupSort = return (caseTuple tupSort xrs, True) wrongArg :: Q (a, Bool) wrongArg = return (caseWrongArg, True) case () of _ | not (or xcs) -> trivial -- Variable does not occur -- At this point we know that xrs, xcs is not empty, -- and at least one xr is True | TupleT len <- f -> tuple $ Boxed len | UnboxedTupleT len <- f -> tuple $ Unboxed len | fc || or (take numFirstArgs xcs) -> wrongArg -- T (..var..) ty_1 ... ty_n | otherwise -- T (..no var..) ty_1 ... ty_n -> do itf <- isInTypeFamilyApp tyVarNames f args if itf -- We can't decompose type families, so -- error if we encounter one here. then wrongArg else return ( caseTyApp $ drop numFirstArgs $ zip args xrs , True ) go co (SigT t k) = do (_, kc) <- go_kind co k if kc then return (caseWrongArg, True) else go co t go co (VarT v) | Map.member v tvMap = return (if co then caseCoVar v else caseVar v, True) | otherwise = trivial go co (ForallT tvbs _ t) = do (tr, tc) <- go co t let tvbNames = map tvName tvbs if not tc || any (`elem` tvbNames) tyVarNames then trivial else return (caseForAll tvbs tr, True) go _ _ = trivial go_kind :: Bool -> Kind -> Q (a, Bool) go_kind = go trivial :: Q (a, Bool) trivial = return (caseTrivial, False) tyVarNames :: [Name] tyVarNames = Map.keys tvMap -- Fold over the arguments of a data constructor in a Functor-like way. foldDataConArgs :: forall a. TyVarMap -> FFoldType a -> ConstructorInfo -> Q [a] foldDataConArgs tvMap ft con = do fieldTys <- mapM resolveTypeSynonyms $ constructorFields con mapM foldArg fieldTys where foldArg :: Type -> Q a foldArg = functorLikeTraverse tvMap ft -- Make a 'LamE' using a fresh variable. mkSimpleLam :: (Exp -> Q Exp) -> Q Exp mkSimpleLam lam = do -- Use an underscore in front of the variable name, as it's possible for -- certain Bifoldable instances to generate code like this (see #89): -- -- @ -- bifoldMap (\\_n -> mempty) ... -- @ -- -- Without the underscore, that code would trigger -Wunused-matches warnings. n <- newName "_n" lamE [varP n] $ lam (VarE n) -- Make a 'LamE' using two fresh variables. mkSimpleLam2 :: (Exp -> Exp -> Q Exp) -> Q Exp mkSimpleLam2 lam = do -- Use an underscore in front of the variable name, as it's possible for -- certain Bifoldable instances to generate code like this (see #89): -- -- @ -- bifoldr (\\_n1 n2 -> n2) ... -- @ -- -- Without the underscore, that code would trigger -Wunused-matches warnings. n1 <- newName "_n1" n2 <- newName "n2" lamE [varP n1, varP n2] $ lam (VarE n1) (VarE n2) -- "Con a1 a2 a3 -> fold [x1 a1, x2 a2, x3 a3]" -- -- @mkSimpleConMatch fold conName insides@ produces a match clause in -- which the LHS pattern-matches on @extraPats@, followed by a match on the -- constructor @conName@ and its arguments. The RHS folds (with @fold@) over -- @conName@ and its arguments, applying an expression (from @insides@) to each -- of the respective arguments of @conName@. mkSimpleConMatch :: (Name -> [a] -> Q Exp) -> Name -> [Exp -> a] -> Q Match mkSimpleConMatch fold conName insides = do varsNeeded <- newNameList "_arg" $ length insides let pat = conPCompat conName (map VarP varsNeeded) rhs <- fold conName (zipWith (\i v -> i $ VarE v) insides varsNeeded) return $ Match pat (NormalB rhs) [] -- "Con a1 a2 a3 -> fmap (\b2 -> Con a1 b2 a3) (traverse f a2)" -- -- @mkSimpleConMatch2 fold conName insides@ behaves very similarly to -- 'mkSimpleConMatch', with two key differences: -- -- 1. @insides@ is a @[(Bool, Exp)]@ instead of a @[Exp]@. This is because it -- filters out the expressions corresponding to arguments whose types do not -- mention the last type variable in a derived 'Foldable' or 'Traversable' -- instance (i.e., those elements of @insides@ containing @False@). -- -- 2. @fold@ takes an expression as its first argument instead of a -- constructor name. This is because it uses a specialized -- constructor function expression that only takes as many parameters as -- there are argument types that mention the last type variable. mkSimpleConMatch2 :: (Exp -> [Exp] -> Q Exp) -> Name -> [(Bool, Exp)] -> Q Match mkSimpleConMatch2 fold conName insides = do varsNeeded <- newNameList "_arg" lengthInsides let pat = conPCompat conName (map VarP varsNeeded) -- Make sure to zip BEFORE invoking catMaybes. We want the variable -- indices in each expression to match up with the argument indices -- in conExpr (defined below). exps = catMaybes $ zipWith (\(m, i) v -> if m then Just (i `AppE` VarE v) else Nothing) insides varsNeeded -- An element of argTysTyVarInfo is True if the constructor argument -- with the same index has a type which mentions the last type -- variable. argTysTyVarInfo = map (\(m, _) -> m) insides (asWithTyVar, asWithoutTyVar) = partitionByList argTysTyVarInfo varsNeeded conExpQ | null asWithTyVar = appsE (conE conName:map varE asWithoutTyVar) | otherwise = do bs <- newNameList "b" lengthInsides let bs' = filterByList argTysTyVarInfo bs vars = filterByLists argTysTyVarInfo (map varE bs) (map varE varsNeeded) lamE (map varP bs') (appsE (conE conName:vars)) conExp <- conExpQ rhs <- fold conExp exps return $ Match pat (NormalB rhs) [] where lengthInsides = length insides -- Indicates whether a tuple is boxed or unboxed, as well as its number of -- arguments. For instance, (a, b) corresponds to @Boxed 2@, and (# a, b, c #) -- corresponds to @Unboxed 3@. data TupleSort = Boxed Int | Unboxed Int -- "case x of (a1,a2,a3) -> fold [x1 a1, x2 a2, x3 a3]" mkSimpleTupleCase :: (Name -> [a] -> Q Match) -> TupleSort -> [a] -> Exp -> Q Exp mkSimpleTupleCase matchForCon tupSort insides x = do let tupDataName = case tupSort of Boxed len -> tupleDataName len Unboxed len -> unboxedTupleDataName len m <- matchForCon tupDataName insides return $ CaseE x [m] -- Adapt to the type of ConP changing in template-haskell-2.18.0.0. conPCompat :: Name -> [Pat] -> Pat conPCompat n pats = ConP n #if MIN_VERSION_template_haskell(2,18,0) [] #endif pats bifunctors-5.6.2/src/Data/Bifunctor/TH/0000755000000000000000000000000007346545000016001 5ustar0000000000000000bifunctors-5.6.2/src/Data/Bifunctor/TH/Internal.hs0000644000000000000000000003401007346545000020107 0ustar0000000000000000{-# LANGUAGE TemplateHaskellQuotes #-} {-# LANGUAGE Unsafe #-} {-| Module: Data.Bifunctor.TH.Internal Copyright: (C) 2008-2016 Edward Kmett, (C) 2015-2016 Ryan Scott License: BSD-style (see the file LICENSE) Maintainer: Edward Kmett Portability: Template Haskell Template Haskell-related utilities. -} module Data.Bifunctor.TH.Internal where import Control.Applicative import Data.Bifunctor (Bifunctor(..)) import Data.Bifoldable (Bifoldable(..)) import Data.Bitraversable (Bitraversable(..)) import Data.Coerce (coerce) import Data.Foldable (foldr') import qualified Data.List as List import qualified Data.Map as Map (singleton) import Data.Map (Map) import Data.Maybe (fromMaybe, mapMaybe) import Data.Monoid (Dual(..), Endo(..)) import qualified Data.Set as Set import Data.Set (Set) import Language.Haskell.TH.Datatype import Language.Haskell.TH.Lib import Language.Haskell.TH.Syntax ------------------------------------------------------------------------------- -- Expanding type synonyms ------------------------------------------------------------------------------- applySubstitutionKind :: Map Name Kind -> Type -> Type applySubstitutionKind = applySubstitution substNameWithKind :: Name -> Kind -> Type -> Type substNameWithKind n k = applySubstitutionKind (Map.singleton n k) substNamesWithKindStar :: [Name] -> Type -> Type substNamesWithKindStar ns t = foldr' (flip substNameWithKind starK) t ns ------------------------------------------------------------------------------- -- Type-specialized const functions ------------------------------------------------------------------------------- bimapConst :: p b d -> (a -> b) -> (c -> d) -> p a c -> p b d bimapConst = const . const . const {-# INLINE bimapConst #-} bifoldrConst :: c -> (a -> c -> c) -> (b -> c -> c) -> c -> p a b -> c bifoldrConst = const . const . const . const {-# INLINE bifoldrConst #-} bifoldMapConst :: m -> (a -> m) -> (b -> m) -> p a b -> m bifoldMapConst = const . const . const {-# INLINE bifoldMapConst #-} bitraverseConst :: f (t c d) -> (a -> f c) -> (b -> f d) -> t a b -> f (t c d) bitraverseConst = const . const . const {-# INLINE bitraverseConst #-} ------------------------------------------------------------------------------- -- StarKindStatus ------------------------------------------------------------------------------- -- | Whether a type is not of kind *, is of kind *, or is a kind variable. data StarKindStatus = NotKindStar | KindStar | IsKindVar Name deriving Eq -- | Does a Type have kind * or k (for some kind variable k)? canRealizeKindStar :: Type -> StarKindStatus canRealizeKindStar t | hasKindStar t = KindStar | otherwise = case t of SigT _ (VarT k) -> IsKindVar k _ -> NotKindStar -- | Returns 'Just' the kind variable 'Name' of a 'StarKindStatus' if it exists. -- Otherwise, returns 'Nothing'. starKindStatusToName :: StarKindStatus -> Maybe Name starKindStatusToName (IsKindVar n) = Just n starKindStatusToName _ = Nothing -- | Concat together all of the StarKindStatuses that are IsKindVar and extract -- the kind variables' Names out. catKindVarNames :: [StarKindStatus] -> [Name] catKindVarNames = mapMaybe starKindStatusToName ------------------------------------------------------------------------------- -- Assorted utilities ------------------------------------------------------------------------------- -- filterByList, filterByLists, and partitionByList taken from GHC (BSD3-licensed) -- | 'filterByList' takes a list of Bools and a list of some elements and -- filters out these elements for which the corresponding value in the list of -- Bools is False. This function does not check whether the lists have equal -- length. filterByList :: [Bool] -> [a] -> [a] filterByList (True:bs) (x:xs) = x : filterByList bs xs filterByList (False:bs) (_:xs) = filterByList bs xs filterByList _ _ = [] -- | 'filterByLists' takes a list of Bools and two lists as input, and -- outputs a new list consisting of elements from the last two input lists. For -- each Bool in the list, if it is 'True', then it takes an element from the -- former list. If it is 'False', it takes an element from the latter list. -- The elements taken correspond to the index of the Bool in its list. -- For example: -- -- @ -- filterByLists [True, False, True, False] \"abcd\" \"wxyz\" = \"axcz\" -- @ -- -- This function does not check whether the lists have equal length. filterByLists :: [Bool] -> [a] -> [a] -> [a] filterByLists (True:bs) (x:xs) (_:ys) = x : filterByLists bs xs ys filterByLists (False:bs) (_:xs) (y:ys) = y : filterByLists bs xs ys filterByLists _ _ _ = [] -- | 'partitionByList' takes a list of Bools and a list of some elements and -- partitions the list according to the list of Bools. Elements corresponding -- to 'True' go to the left; elements corresponding to 'False' go to the right. -- For example, @partitionByList [True, False, True] [1,2,3] == ([1,3], [2])@ -- This function does not check whether the lists have equal -- length. partitionByList :: [Bool] -> [a] -> ([a], [a]) partitionByList = go [] [] where go trues falses (True : bs) (x : xs) = go (x:trues) falses bs xs go trues falses (False : bs) (x : xs) = go trues (x:falses) bs xs go trues falses _ _ = (reverse trues, reverse falses) -- | Returns True if a Type has kind *. hasKindStar :: Type -> Bool hasKindStar VarT{} = True hasKindStar (SigT _ StarT) = True hasKindStar _ = False -- Returns True is a kind is equal to *, or if it is a kind variable. isStarOrVar :: Kind -> Bool isStarOrVar StarT = True isStarOrVar VarT{} = True isStarOrVar _ = False -- | @hasKindVarChain n kind@ Checks if @kind@ is of the form -- k_0 -> k_1 -> ... -> k_(n-1), where k0, k1, ..., and k_(n-1) can be * or -- kind variables. hasKindVarChain :: Int -> Type -> Maybe [Name] hasKindVarChain kindArrows t = let uk = uncurryKind (tyKind t) in if (length uk - 1 == kindArrows) && all isStarOrVar uk then Just (freeVariables uk) else Nothing -- | If a Type is a SigT, returns its kind signature. Otherwise, return *. tyKind :: Type -> Kind tyKind (SigT _ k) = k tyKind _ = starK -- | A mapping of type variable Names to their map function Names. For example, in a -- Bifunctor declaration, a TyVarMap might look like (a ~> f, b ~> g), where -- a and b are the last two type variables of the datatype, and f and g are the two -- functions which map their respective type variables. type TyVarMap = Map Name Name thd3 :: (a, b, c) -> c thd3 (_, _, c) = c unsnoc :: [a] -> Maybe ([a], a) unsnoc [] = Nothing unsnoc (x:xs) = case unsnoc xs of Nothing -> Just ([], x) Just (a,b) -> Just (x:a, b) -- | Generate a list of fresh names with a common prefix, and numbered suffixes. newNameList :: String -> Int -> Q [Name] newNameList prefix n = mapM (newName . (prefix ++) . show) [1..n] -- | Applies a typeclass constraint to a type. applyClass :: Name -> Name -> Pred applyClass con t = AppT (ConT con) (VarT t) -- | Checks to see if the last types in a data family instance can be safely eta- -- reduced (i.e., dropped), given the other types. This checks for three conditions: -- -- (1) All of the dropped types are type variables -- (2) All of the dropped types are distinct -- (3) None of the remaining types mention any of the dropped types canEtaReduce :: [Type] -> [Type] -> Bool canEtaReduce remaining dropped = all isTyVar dropped && allDistinct droppedNames -- Make sure not to pass something of type [Type], since Type -- didn't have an Ord instance until template-haskell-2.10.0.0 && not (any (`mentionsName` droppedNames) remaining) where droppedNames :: [Name] droppedNames = map varTToName dropped -- | Extract Just the Name from a type variable. If the argument Type is not a -- type variable, return Nothing. varTToName_maybe :: Type -> Maybe Name varTToName_maybe (VarT n) = Just n varTToName_maybe (SigT t _) = varTToName_maybe t varTToName_maybe _ = Nothing -- | Extract the Name from a type variable. If the argument Type is not a -- type variable, throw an error. varTToName :: Type -> Name varTToName = fromMaybe (error "Not a type variable!") . varTToName_maybe -- | Peel off a kind signature from a Type (if it has one). unSigT :: Type -> Type unSigT (SigT t _) = t unSigT t = t -- | Is the given type a variable? isTyVar :: Type -> Bool isTyVar (VarT _) = True isTyVar (SigT t _) = isTyVar t isTyVar _ = False -- | Detect if a Name in a list of provided Names occurs as an argument to some -- type family. This makes an effort to exclude /oversaturated/ arguments to -- type families. For instance, if one declared the following type family: -- -- @ -- type family F a :: Type -> Type -- @ -- -- Then in the type @F a b@, we would consider @a@ to be an argument to @F@, -- but not @b@. isInTypeFamilyApp :: [Name] -> Type -> [Type] -> Q Bool isInTypeFamilyApp names tyFun tyArgs = case tyFun of ConT tcName -> go tcName _ -> return False where go :: Name -> Q Bool go tcName = do info <- reify tcName case info of FamilyI (OpenTypeFamilyD (TypeFamilyHead _ bndrs _ _)) _ -> withinFirstArgs bndrs FamilyI (ClosedTypeFamilyD (TypeFamilyHead _ bndrs _ _) _) _ -> withinFirstArgs bndrs _ -> return False where withinFirstArgs :: [a] -> Q Bool withinFirstArgs bndrs = let firstArgs = take (length bndrs) tyArgs argFVs = freeVariables firstArgs in return $ any (`elem` argFVs) names -- | Are all of the items in a list (which have an ordering) distinct? -- -- This uses Set (as opposed to nub) for better asymptotic time complexity. allDistinct :: Ord a => [a] -> Bool allDistinct = allDistinct' Set.empty where allDistinct' :: Ord a => Set a -> [a] -> Bool allDistinct' uniqs (x:xs) | x `Set.member` uniqs = False | otherwise = allDistinct' (Set.insert x uniqs) xs allDistinct' _ _ = True -- | Does the given type mention any of the Names in the list? mentionsName :: Type -> [Name] -> Bool mentionsName = go where go :: Type -> [Name] -> Bool go (AppT t1 t2) names = go t1 names || go t2 names go (SigT t k) names = go t names || go k names go (VarT n) names = n `elem` names go _ _ = False -- | Does an instance predicate mention any of the Names in the list? predMentionsName :: Pred -> [Name] -> Bool predMentionsName = mentionsName -- | Construct a type via curried application. applyTy :: Type -> [Type] -> Type applyTy = List.foldl' AppT -- | Fully applies a type constructor to its type variables. applyTyCon :: Name -> [Type] -> Type applyTyCon = applyTy . ConT -- | Split an applied type into its individual components. For example, this: -- -- @ -- Either Int Char -- @ -- -- would split to this: -- -- @ -- [Either, Int, Char] -- @ unapplyTy :: Type -> (Type, [Type]) unapplyTy ty = go ty ty [] where go :: Type -> Type -> [Type] -> (Type, [Type]) go _ (AppT ty1 ty2) args = go ty1 ty1 (ty2:args) go origTy (SigT ty' _) args = go origTy ty' args go origTy (InfixT ty1 n ty2) args = go origTy (ConT n `AppT` ty1 `AppT` ty2) args go origTy (ParensT ty') args = go origTy ty' args go origTy _ args = (origTy, args) -- | Split a type signature by the arrows on its spine. For example, this: -- -- @ -- forall a b. (a ~ b) => (a -> b) -> Char -> () -- @ -- -- would split to this: -- -- @ -- (a ~ b, [a -> b, Char, ()]) -- @ uncurryTy :: Type -> (Cxt, [Type]) uncurryTy (AppT (AppT ArrowT t1) t2) = let (ctxt, tys) = uncurryTy t2 in (ctxt, t1:tys) uncurryTy (SigT t _) = uncurryTy t uncurryTy (ForallT _ ctxt t) = let (ctxt', tys) = uncurryTy t in (ctxt ++ ctxt', tys) uncurryTy t = ([], [t]) -- | Like uncurryType, except on a kind level. uncurryKind :: Kind -> [Kind] uncurryKind = snd . uncurryTy ------------------------------------------------------------------------------- -- Quoted names ------------------------------------------------------------------------------- bimapConstValName :: Name bimapConstValName = 'bimapConst bifoldrConstValName :: Name bifoldrConstValName = 'bifoldrConst bifoldMapConstValName :: Name bifoldMapConstValName = 'bifoldMapConst coerceValName :: Name coerceValName = 'coerce bitraverseConstValName :: Name bitraverseConstValName = 'bitraverseConst wrapMonadDataName :: Name wrapMonadDataName = 'WrapMonad functorTypeName :: Name functorTypeName = ''Functor foldableTypeName :: Name foldableTypeName = ''Foldable traversableTypeName :: Name traversableTypeName = ''Traversable composeValName :: Name composeValName = '(.) idValName :: Name idValName = 'id errorValName :: Name errorValName = 'error flipValName :: Name flipValName = 'flip fmapValName :: Name fmapValName = 'fmap foldrValName :: Name foldrValName = 'foldr foldMapValName :: Name foldMapValName = 'foldMap seqValName :: Name seqValName = 'seq traverseValName :: Name traverseValName = 'traverse unwrapMonadValName :: Name unwrapMonadValName = 'unwrapMonad bifunctorTypeName :: Name bifunctorTypeName = ''Bifunctor bimapValName :: Name bimapValName = 'bimap pureValName :: Name pureValName = 'pure apValName :: Name apValName = '(<*>) liftA2ValName :: Name liftA2ValName = 'liftA2 mappendValName :: Name mappendValName = 'mappend memptyValName :: Name memptyValName = 'mempty bifoldableTypeName :: Name bifoldableTypeName = ''Bifoldable bitraversableTypeName :: Name bitraversableTypeName = ''Bitraversable bifoldrValName :: Name bifoldrValName = 'bifoldr bifoldMapValName :: Name bifoldMapValName = 'bifoldMap bitraverseValName :: Name bitraverseValName = 'bitraverse appEndoValName :: Name appEndoValName = 'appEndo dualDataName :: Name dualDataName = 'Dual endoDataName :: Name endoDataName = 'Endo getDualValName :: Name getDualValName = 'getDual bifunctors-5.6.2/src/Data/Bifunctor/Tannen.hs0000644000000000000000000001320407346545000017245 0ustar0000000000000000{-# LANGUAGE DeriveGeneric #-} {-# LANGUAGE EmptyDataDecls #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE PolyKinds #-} {-# LANGUAGE Safe #-} {-# LANGUAGE StandaloneDeriving #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE TypeOperators #-} ----------------------------------------------------------------------------- -- | -- Copyright : (C) 2008-2016 Edward Kmett -- License : BSD-style (see the file LICENSE) -- -- Maintainer : Edward Kmett -- Stability : provisional -- Portability : portable -- ---------------------------------------------------------------------------- module Data.Bifunctor.Tannen ( Tannen(..) ) where import Control.Applicative import Control.Arrow as A import Control.Category import Control.Comonad import Data.Bifunctor as B import Data.Bifunctor.Functor import Data.Bifunctor.Swap (Swap (..)) import Data.Biapplicative import Data.Bifoldable import Data.Bifoldable1 (Bifoldable1(..)) import Data.Bitraversable import Data.Foldable1 (Foldable1(..)) import Data.Functor.Classes import GHC.Generics import Prelude hiding ((.),id) -- | Compose a 'Functor' on the outside of a 'Bifunctor'. newtype Tannen f p a b = Tannen { runTannen :: f (p a b) } deriving (Eq, Ord, Show, Read, Generic) deriving instance Functor f => Generic1 (Tannen f p a) instance (Eq1 f, Eq2 p, Eq a) => Eq1 (Tannen f p a) where liftEq = liftEq2 (==) instance (Eq1 f, Eq2 p) => Eq2 (Tannen f p) where liftEq2 f g (Tannen x) (Tannen y) = liftEq (liftEq2 f g) x y instance (Ord1 f, Ord2 p, Ord a) => Ord1 (Tannen f p a) where liftCompare = liftCompare2 compare instance (Ord1 f, Ord2 p) => Ord2 (Tannen f p) where liftCompare2 f g (Tannen x) (Tannen y) = liftCompare (liftCompare2 f g) x y instance (Read1 f, Read2 p, Read a) => Read1 (Tannen f p a) where liftReadsPrec = liftReadsPrec2 readsPrec readList instance (Read1 f, Read2 p) => Read2 (Tannen f p) where liftReadsPrec2 rp1 rl1 rp2 rl2 p = readParen (p > 10) $ \s0 -> do ("Tannen", s1) <- lex s0 ("{", s2) <- lex s1 ("runTannen", s3) <- lex s2 (x, s4) <- liftReadsPrec (liftReadsPrec2 rp1 rl1 rp2 rl2) (liftReadList2 rp1 rl1 rp2 rl2) 0 s3 ("}", s5) <- lex s4 return (Tannen x, s5) instance (Show1 f, Show2 p, Show a) => Show1 (Tannen f p a) where liftShowsPrec = liftShowsPrec2 showsPrec showList instance (Show1 f, Show2 p) => Show2 (Tannen f p) where liftShowsPrec2 sp1 sl1 sp2 sl2 p (Tannen x) = showParen (p > 10) $ showString "Tannen {runTannen = " . liftShowsPrec (liftShowsPrec2 sp1 sl1 sp2 sl2) (liftShowList2 sp1 sl1 sp2 sl2) 0 x . showChar '}' instance Functor f => BifunctorFunctor (Tannen f) where bifmap f (Tannen fp) = Tannen (fmap f fp) instance (Functor f, Monad f) => BifunctorMonad (Tannen f) where bireturn = Tannen . return bibind f (Tannen fp) = Tannen $ fp >>= runTannen . f instance Comonad f => BifunctorComonad (Tannen f) where biextract = extract . runTannen biextend f (Tannen fp) = Tannen (extend (f . Tannen) fp) instance (Functor f, Bifunctor p) => Bifunctor (Tannen f p) where first f = Tannen . fmap (B.first f) . runTannen {-# INLINE first #-} second f = Tannen . fmap (B.second f) . runTannen {-# INLINE second #-} bimap f g = Tannen . fmap (bimap f g) . runTannen {-# INLINE bimap #-} instance (Functor f, Bifunctor p) => Functor (Tannen f p a) where fmap f = Tannen . fmap (B.second f) . runTannen {-# INLINE fmap #-} instance (Applicative f, Biapplicative p) => Biapplicative (Tannen f p) where bipure a b = Tannen (pure (bipure a b)) {-# INLINE bipure #-} Tannen fg <<*>> Tannen xy = Tannen ((<<*>>) <$> fg <*> xy) {-# INLINE (<<*>>) #-} instance (Foldable f, Bifoldable p) => Foldable (Tannen f p a) where foldMap f = foldMap (bifoldMap (const mempty) f) . runTannen {-# INLINE foldMap #-} instance (Foldable f, Bifoldable p) => Bifoldable (Tannen f p) where bifoldMap f g = foldMap (bifoldMap f g) . runTannen {-# INLINE bifoldMap #-} instance (Foldable1 f, Bifoldable1 p) => Bifoldable1 (Tannen f p) where bifoldMap1 f g = foldMap1 (bifoldMap1 f g) . runTannen {-# INLINE bifoldMap1 #-} instance (Traversable f, Bitraversable p) => Traversable (Tannen f p a) where traverse f = fmap Tannen . traverse (bitraverse pure f) . runTannen {-# INLINE traverse #-} instance (Traversable f, Bitraversable p) => Bitraversable (Tannen f p) where bitraverse f g = fmap Tannen . traverse (bitraverse f g) . runTannen {-# INLINE bitraverse #-} instance (Applicative f, Category p) => Category (Tannen f p) where id = Tannen $ pure id Tannen fpbc . Tannen fpab = Tannen $ liftA2 (.) fpbc fpab instance (Applicative f, Arrow p) => Arrow (Tannen f p) where arr f = Tannen $ pure $ arr f first = Tannen . fmap A.first . runTannen second = Tannen . fmap A.second . runTannen Tannen ab *** Tannen cd = Tannen $ liftA2 (***) ab cd Tannen ab &&& Tannen ac = Tannen $ liftA2 (&&&) ab ac instance (Applicative f, ArrowChoice p) => ArrowChoice (Tannen f p) where left = Tannen . fmap left . runTannen right = Tannen . fmap right . runTannen Tannen ab +++ Tannen cd = Tannen $ liftA2 (+++) ab cd Tannen ac ||| Tannen bc = Tannen $ liftA2 (|||) ac bc instance (Applicative f, ArrowLoop p) => ArrowLoop (Tannen f p) where loop = Tannen . fmap loop . runTannen instance (Applicative f, ArrowZero p) => ArrowZero (Tannen f p) where zeroArrow = Tannen $ pure zeroArrow instance (Applicative f, ArrowPlus p) => ArrowPlus (Tannen f p) where Tannen f <+> Tannen g = Tannen (liftA2 (<+>) f g) -- | @since 5.6.1 instance (Functor f, Swap p) => Swap (Tannen f p) where swap = Tannen . fmap swap . runTannen bifunctors-5.6.2/src/Data/Bifunctor/Wrapped.hs0000644000000000000000000000711707346545000017432 0ustar0000000000000000{-# LANGUAGE DeriveGeneric #-} {-# LANGUAGE EmptyDataDecls #-} {-# LANGUAGE PolyKinds #-} {-# LANGUAGE Safe #-} {-# LANGUAGE TypeFamilies #-} ----------------------------------------------------------------------------- -- | -- Copyright : (C) 2008-2016 Edward Kmett -- License : BSD-style (see the file LICENSE) -- -- Maintainer : Edward Kmett -- Stability : provisional -- Portability : portable -- ---------------------------------------------------------------------------- module Data.Bifunctor.Wrapped ( WrappedBifunctor(..) ) where import Data.Biapplicative import Data.Bifoldable import Data.Bifoldable1 (Bifoldable1(..)) import Data.Bitraversable import Data.Functor.Classes import GHC.Generics -- | Make a 'Functor' over the second argument of a 'Bifunctor'. newtype WrappedBifunctor p a b = WrapBifunctor { unwrapBifunctor :: p a b } deriving (Eq, Ord, Show, Read, Generic, Generic1) instance (Eq2 p, Eq a) => Eq1 (WrappedBifunctor p a) where liftEq = liftEq2 (==) instance Eq2 p => Eq2 (WrappedBifunctor p) where liftEq2 f g (WrapBifunctor x) (WrapBifunctor y) = liftEq2 f g x y instance (Ord2 p, Ord a) => Ord1 (WrappedBifunctor p a) where liftCompare = liftCompare2 compare instance Ord2 p => Ord2 (WrappedBifunctor p) where liftCompare2 f g (WrapBifunctor x) (WrapBifunctor y) = liftCompare2 f g x y instance (Read2 p, Read a) => Read1 (WrappedBifunctor p a) where liftReadsPrec = liftReadsPrec2 readsPrec readList instance Read2 p => Read2 (WrappedBifunctor p) where liftReadsPrec2 rp1 rl1 rp2 rl2 p = readParen (p > 10) $ \s0 -> do ("WrapBifunctor", s1) <- lex s0 ("{", s2) <- lex s1 ("unwrapBifunctor", s3) <- lex s2 (x, s4) <- liftReadsPrec2 rp1 rl1 rp2 rl2 0 s3 ("}", s5) <- lex s4 return (WrapBifunctor x, s5) instance (Show2 p, Show a) => Show1 (WrappedBifunctor p a) where liftShowsPrec = liftShowsPrec2 showsPrec showList instance Show2 p => Show2 (WrappedBifunctor p) where liftShowsPrec2 sp1 sl1 sp2 sl2 p (WrapBifunctor x) = showParen (p > 10) $ showString "WrapBifunctor {unwrapBifunctor = " . liftShowsPrec2 sp1 sl1 sp2 sl2 0 x . showChar '}' instance Bifunctor p => Bifunctor (WrappedBifunctor p) where first f = WrapBifunctor . first f . unwrapBifunctor {-# INLINE first #-} second f = WrapBifunctor . second f . unwrapBifunctor {-# INLINE second #-} bimap f g = WrapBifunctor . bimap f g . unwrapBifunctor {-# INLINE bimap #-} instance Bifunctor p => Functor (WrappedBifunctor p a) where fmap f = WrapBifunctor . second f . unwrapBifunctor {-# INLINE fmap #-} instance Biapplicative p => Biapplicative (WrappedBifunctor p) where bipure a b = WrapBifunctor (bipure a b) {-# INLINE bipure #-} WrapBifunctor fg <<*>> WrapBifunctor xy = WrapBifunctor (fg <<*>> xy) {-# INLINE (<<*>>) #-} instance Bifoldable p => Foldable (WrappedBifunctor p a) where foldMap f = bifoldMap (const mempty) f . unwrapBifunctor {-# INLINE foldMap #-} instance Bifoldable p => Bifoldable (WrappedBifunctor p) where bifoldMap f g = bifoldMap f g . unwrapBifunctor {-# INLINE bifoldMap #-} instance Bifoldable1 p => Bifoldable1 (WrappedBifunctor p) where bifoldMap1 f g = bifoldMap1 f g . unwrapBifunctor {-# INLINE bifoldMap1 #-} instance Bitraversable p => Traversable (WrappedBifunctor p a) where traverse f = fmap WrapBifunctor . bitraverse pure f . unwrapBifunctor {-# INLINE traverse #-} instance Bitraversable p => Bitraversable (WrappedBifunctor p) where bitraverse f g = fmap WrapBifunctor . bitraverse f g . unwrapBifunctor {-# INLINE bitraverse #-} bifunctors-5.6.2/tests/0000755000000000000000000000000007346545000013235 5ustar0000000000000000bifunctors-5.6.2/tests/BifunctorSpec.hs0000644000000000000000000004420007346545000016337 0ustar0000000000000000{-# LANGUAGE DeriveFoldable #-} {-# LANGUAGE DeriveFunctor #-} {-# LANGUAGE DeriveTraversable #-} {-# LANGUAGE EmptyCase #-} {-# LANGUAGE EmptyDataDecls #-} {-# LANGUAGE ExistentialQuantification #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE GADTs #-} {-# LANGUAGE GeneralizedNewtypeDeriving #-} {-# LANGUAGE MagicHash #-} {-# LANGUAGE RankNTypes #-} {-# LANGUAGE RoleAnnotations #-} {-# LANGUAGE StandaloneDeriving #-} {-# LANGUAGE TemplateHaskell #-} {-# LANGUAGE TupleSections #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE TypeOperators #-} {-# LANGUAGE UndecidableInstances #-} {-# OPTIONS_GHC -Wno-name-shadowing #-} {-# OPTIONS_GHC -Wno-unused-matches #-} {-# OPTIONS_GHC -Wno-unused-foralls #-} {-| Module: BifunctorSpec Copyright: (C) 2008-2015 Edward Kmett, (C) 2015 Ryan Scott License: BSD-style (see the file LICENSE) Maintainer: Edward Kmett Portability: Template Haskell @hspec@ tests for the "Data.Bifunctor.TH" module. -} module BifunctorSpec where import Data.Bifunctor import Data.Bifunctor.TH import Data.Bifoldable import Data.Bitraversable import Data.Char (chr) import Data.Functor.Classes (Eq1, Show1) import Data.Functor.Compose (Compose(..)) import Data.Functor.Identity (Identity(..)) import Data.Monoid import GHC.Exts (Int#) import Test.Hspec import Test.Hspec.QuickCheck (prop) import Test.QuickCheck (Arbitrary) ------------------------------------------------------------------------------- -- Adapted from the test cases from -- https://ghc.haskell.org/trac/ghc/attachment/ticket/2953/deriving-functor-tests.patch -- Plain data types data Strange a b c = T1 a b c | T2 [a] [b] [c] -- lists | T3 [[a]] [[b]] [[c]] -- nested lists | T4 (c,(b,b),(c,c)) -- tuples | T5 ([c],Strange a b c) -- tycons deriving (Functor, Foldable, Traversable) type IntFun a b = (b -> Int) -> a data StrangeFunctions a b c = T6 (a -> c) -- function types | T7 (a -> (c,a)) -- functions and tuples | T8 ((b -> a) -> c) -- continuation | T9 (IntFun b c) -- type synonyms deriving Functor data StrangeGADT a b where T10 :: Ord d => d -> StrangeGADT c d T11 :: Int -> StrangeGADT e Int T12 :: c ~ Int => c -> StrangeGADT f Int T13 :: i ~ Int => Int -> StrangeGADT h i T14 :: k ~ Int => k -> StrangeGADT j k T15 :: (n ~ c, c ~ Int) => Int -> c -> StrangeGADT m n instance Foldable (StrangeGADT a) where foldMap f (T10 x) = f x foldMap f (T11 _) = mempty foldMap f (T12 _) = mempty foldMap f (T13 _) = mempty foldMap f (T14 x) = f x foldMap f (T15 _ _) = mempty data NotPrimitivelyRecursive a b = S1 (NotPrimitivelyRecursive (a,a) (b, a)) | S2 a | S3 b deriving (Functor, Foldable, Traversable) newtype OneTwoCompose f g a b = OneTwoCompose (f (g a b)) deriving (Arbitrary, Eq, Foldable, Functor, Show, Traversable) newtype ComplexConstraint f g a b = ComplexConstraint (f Int Int (g a,a,b)) instance (Bifunctor (f Int), Functor g) => Functor (ComplexConstraint f g a) where fmap f (ComplexConstraint x) = ComplexConstraint (bimap id (\(ga,a,b) -> (ga,a,f b)) x) instance (Bifoldable (f Int), Foldable g) => Foldable (ComplexConstraint f g a) where foldMap f (ComplexConstraint x) = bifoldMap (const mempty) (\(_,_,b) -> f b) x instance (Bitraversable (f Int), Traversable g) => Traversable (ComplexConstraint f g a) where traverse f (ComplexConstraint x) = ComplexConstraint `fmap` bitraverse pure (\(ga,a,b) -> (ga,a,) `fmap` f b) x data Universal a b = Universal (forall b. (b,[a])) | Universal2 (forall f. Bifunctor f => f a b) | Universal3 (forall a. Maybe a) -- reuse a | NotReallyUniversal (forall b. a) instance Functor (Universal a) where fmap f (Universal x) = Universal x fmap f (Universal2 x) = Universal2 (bimap id f x) fmap f (Universal3 x) = Universal3 x fmap f (NotReallyUniversal x) = NotReallyUniversal x data Existential a b = forall a. ExistentialList [a] | forall f. Bitraversable f => ExistentialFunctor (f a b) | forall b. SneakyUseSameName (Maybe b) instance Functor (Existential a) where fmap f (ExistentialList x) = ExistentialList x fmap f (ExistentialFunctor x) = ExistentialFunctor (bimap id f x) fmap f (SneakyUseSameName x) = SneakyUseSameName x instance Foldable (Existential a) where foldMap f (ExistentialList _) = mempty foldMap f (ExistentialFunctor x) = bifoldMap (const mempty) f x foldMap f (SneakyUseSameName _) = mempty instance Traversable (Existential a) where traverse f (ExistentialList x) = pure $ ExistentialList x traverse f (ExistentialFunctor x) = ExistentialFunctor `fmap` bitraverse pure f x traverse f (SneakyUseSameName x) = pure $ SneakyUseSameName x data IntHash a b = IntHash Int# Int# | IntHashTuple Int# a b (a, b, Int, IntHash Int (a, b, Int)) deriving (Functor, Foldable) instance Traversable (IntHash a) where traverse f (IntHash x y) = pure (IntHash x y) traverse f (IntHashTuple x y z (a,b,c,d)) = (\z' b' d' -> IntHashTuple x y z' (a,b',c,d')) `fmap` f z <*> f b <*> traverse (\(m,n,o) -> fmap (\n' -> (m,n',o)) (f n)) d data IntHashFun a b = IntHashFun ((((a -> Int#) -> b) -> Int#) -> a) deriving Functor data Empty1 a b deriving (Functor, Foldable, Traversable) data Empty2 a b deriving (Functor, Foldable, Traversable) type role Empty2 nominal nominal data TyCon81 a b = TyCon81a (forall c. c -> (forall d. a -> d) -> a) | TyCon81b (Int -> forall c. c -> b) instance Functor (TyCon81 a) where fmap f (TyCon81a g) = TyCon81a g fmap f (TyCon81b g) = TyCon81b (\x y -> f (g x y)) type family F :: * -> * -> * type instance F = Either data TyCon82 a b = TyCon82 (F a b) deriving (Functor, Foldable, Traversable) -- Data families data family StrangeFam x y z data instance StrangeFam a b c = T1Fam a b c | T2Fam [a] [b] [c] -- lists | T3Fam [[a]] [[b]] [[c]] -- nested lists | T4Fam (c,(b,b),(c,c)) -- tuples | T5Fam ([c],Strange a b c) -- tycons deriving (Functor, Foldable, Traversable) data family StrangeFunctionsFam x y z data instance StrangeFunctionsFam a b c = T6Fam (a -> c) -- function types | T7Fam (a -> (c,a)) -- functions and tuples | T8Fam ((b -> a) -> c) -- continuation | T9Fam (IntFun b c) -- type synonyms deriving Functor data family StrangeGADTFam x y data instance StrangeGADTFam a b where T10Fam :: Ord d => d -> StrangeGADTFam c d T11Fam :: Int -> StrangeGADTFam e Int T12Fam :: c ~ Int => c -> StrangeGADTFam f Int T13Fam :: i ~ Int => Int -> StrangeGADTFam h i T14Fam :: k ~ Int => k -> StrangeGADTFam j k T15Fam :: (n ~ c, c ~ Int) => Int -> c -> StrangeGADTFam m n instance Foldable (StrangeGADTFam a) where foldMap f (T10Fam x) = f x foldMap f (T11Fam _) = mempty foldMap f (T12Fam _) = mempty foldMap f (T13Fam _) = mempty foldMap f (T14Fam x) = f x foldMap f (T15Fam _ _) = mempty data family NotPrimitivelyRecursiveFam x y data instance NotPrimitivelyRecursiveFam a b = S1Fam (NotPrimitivelyRecursive (a,a) (b, a)) | S2Fam a | S3Fam b deriving (Functor, Foldable, Traversable) data family OneTwoComposeFam (j :: * -> *) (k :: * -> * -> *) x y newtype instance OneTwoComposeFam f g a b = OneTwoComposeFam (f (g a b)) deriving ( Arbitrary, Eq, Show , Functor, Foldable, Traversable ) data family ComplexConstraintFam (j :: * -> * -> * -> *) (k :: * -> *) x y newtype instance ComplexConstraintFam f g a b = ComplexConstraintFam (f Int Int (g a,a,b)) instance (Bifunctor (f Int), Functor g) => Functor (ComplexConstraintFam f g a) where fmap f (ComplexConstraintFam x) = ComplexConstraintFam (bimap id (\(ga,a,b) -> (ga,a,f b)) x) instance (Bifoldable (f Int), Foldable g) => Foldable (ComplexConstraintFam f g a) where foldMap f (ComplexConstraintFam x) = bifoldMap (const mempty) (\(_,_,b) -> f b) x instance (Bitraversable (f Int), Traversable g) => Traversable (ComplexConstraintFam f g a) where traverse f (ComplexConstraintFam x) = ComplexConstraintFam `fmap` bitraverse pure (\(ga,a,b) -> (ga,a,) `fmap` f b) x data family UniversalFam x y data instance UniversalFam a b = UniversalFam (forall b. (b,[a])) | Universal2Fam (forall f. Bifunctor f => f a b) | Universal3Fam (forall a. Maybe a) -- reuse a | NotReallyUniversalFam (forall b. a) instance Functor (UniversalFam a) where fmap f (UniversalFam x) = UniversalFam x fmap f (Universal2Fam x) = Universal2Fam (bimap id f x) fmap f (Universal3Fam x) = Universal3Fam x fmap f (NotReallyUniversalFam x) = NotReallyUniversalFam x data family ExistentialFam x y data instance ExistentialFam a b = forall a. ExistentialListFam [a] | forall f. Bitraversable f => ExistentialFunctorFam (f a b) | forall b. SneakyUseSameNameFam (Maybe b) instance Functor (ExistentialFam a) where fmap f (ExistentialListFam x) = ExistentialListFam x fmap f (ExistentialFunctorFam x) = ExistentialFunctorFam (bimap id f x) fmap f (SneakyUseSameNameFam x) = SneakyUseSameNameFam x instance Foldable (ExistentialFam a) where foldMap f (ExistentialListFam _) = mempty foldMap f (ExistentialFunctorFam x) = bifoldMap (const mempty) f x foldMap f (SneakyUseSameNameFam _) = mempty instance Traversable (ExistentialFam a) where traverse f (ExistentialListFam x) = pure $ ExistentialListFam x traverse f (ExistentialFunctorFam x) = ExistentialFunctorFam `fmap` bitraverse pure f x traverse f (SneakyUseSameNameFam x) = pure $ SneakyUseSameNameFam x data family IntHashFam x y data instance IntHashFam a b = IntHashFam Int# Int# | IntHashTupleFam Int# a b (a, b, Int, IntHashFam Int (a, b, Int)) deriving (Functor, Foldable, Traversable) data family IntHashFunFam x y data instance IntHashFunFam a b = IntHashFunFam ((((a -> Int#) -> b) -> Int#) -> a) deriving Functor data family TyFamily81 x y data instance TyFamily81 a b = TyFamily81a (forall c. c -> (forall d. a -> d) -> a) | TyFamily81b (Int -> forall c. c -> b) instance Functor (TyFamily81 a) where fmap f (TyFamily81a g) = TyFamily81a g fmap f (TyFamily81b g) = TyFamily81b (\x y -> f (g x y)) data family TyFamily82 x y data instance TyFamily82 a b = TyFamily82 (F a b) deriving (Functor, Foldable, Traversable) ------------------------------------------------------------------------------- -- Plain data types $(deriveBifunctor ''Strange) $(deriveBifoldable ''Strange) $(deriveBitraversable ''Strange) $(deriveBifunctor ''StrangeFunctions) $(deriveBifoldable ''StrangeGADT) $(deriveBifunctor ''NotPrimitivelyRecursive) $(deriveBifoldable ''NotPrimitivelyRecursive) $(deriveBitraversable ''NotPrimitivelyRecursive) $(deriveBifunctor ''OneTwoCompose) $(deriveBifoldable ''OneTwoCompose) $(deriveBitraversable ''OneTwoCompose) instance (Bifunctor (f Int), Functor g) => Bifunctor (ComplexConstraint f g) where bimap = $(makeBimap ''ComplexConstraint) instance (Bifoldable (f Int), Foldable g) => Bifoldable (ComplexConstraint f g) where bifoldr = $(makeBifoldr ''ComplexConstraint) bifoldMap = $(makeBifoldMap ''ComplexConstraint) bifoldlComplexConstraint :: (Bifoldable (f Int), Foldable g) => (c -> a -> c) -> (c -> b -> c) -> c -> ComplexConstraint f g a b -> c bifoldlComplexConstraint = $(makeBifoldl ''ComplexConstraint) bifoldComplexConstraint :: (Bifoldable (f Int), Foldable g, Monoid m) => ComplexConstraint f g m m -> m bifoldComplexConstraint = $(makeBifold ''ComplexConstraint) instance (Bitraversable (f Int), Traversable g) => Bitraversable (ComplexConstraint f g) where bitraverse = $(makeBitraverse ''ComplexConstraint) bisequenceAComplexConstraint :: (Bitraversable (f Int), Traversable g, Applicative t) => ComplexConstraint f g (t a) (t b) -> t (ComplexConstraint f g a b) bisequenceAComplexConstraint = $(makeBisequenceA ''ComplexConstraint) $(deriveBifunctor ''Universal) $(deriveBifunctor ''Existential) $(deriveBifoldable ''Existential) $(deriveBitraversable ''Existential) $(deriveBifunctor ''IntHash) $(deriveBifoldable ''IntHash) $(deriveBitraversable ''IntHash) $(deriveBifunctor ''IntHashFun) $(deriveBifunctor ''Empty1) $(deriveBifoldable ''Empty1) $(deriveBitraversable ''Empty1) -- Use EmptyCase here $(deriveBifunctorOptions defaultOptions{emptyCaseBehavior = True} ''Empty2) $(deriveBifoldableOptions defaultOptions{emptyCaseBehavior = True} ''Empty2) $(deriveBitraversableOptions defaultOptions{emptyCaseBehavior = True} ''Empty2) $(deriveBifunctor ''TyCon81) $(deriveBifunctor ''TyCon82) $(deriveBifoldable ''TyCon82) $(deriveBitraversable ''TyCon82) -- Data families $(deriveBifunctor 'T1Fam) $(deriveBifoldable 'T2Fam) $(deriveBitraversable 'T3Fam) $(deriveBifunctor 'T6Fam) $(deriveBifoldable 'T10Fam) $(deriveBifunctor 'S1Fam) $(deriveBifoldable 'S2Fam) $(deriveBitraversable 'S3Fam) $(deriveBifunctor 'OneTwoComposeFam) $(deriveBifoldable 'OneTwoComposeFam) $(deriveBitraversable 'OneTwoComposeFam) instance (Bifunctor (f Int), Functor g) => Bifunctor (ComplexConstraintFam f g) where bimap = $(makeBimap 'ComplexConstraintFam) instance (Bifoldable (f Int), Foldable g) => Bifoldable (ComplexConstraintFam f g) where bifoldr = $(makeBifoldr 'ComplexConstraintFam) bifoldMap = $(makeBifoldMap 'ComplexConstraintFam) bifoldlComplexConstraintFam :: (Bifoldable (f Int), Foldable g) => (c -> a -> c) -> (c -> b -> c) -> c -> ComplexConstraintFam f g a b -> c bifoldlComplexConstraintFam = $(makeBifoldl 'ComplexConstraintFam) bifoldComplexConstraintFam :: (Bifoldable (f Int), Foldable g, Monoid m) => ComplexConstraintFam f g m m -> m bifoldComplexConstraintFam = $(makeBifold 'ComplexConstraintFam) instance (Bitraversable (f Int), Traversable g) => Bitraversable (ComplexConstraintFam f g) where bitraverse = $(makeBitraverse 'ComplexConstraintFam) bisequenceAComplexConstraintFam :: (Bitraversable (f Int), Traversable g, Applicative t) => ComplexConstraintFam f g (t a) (t b) -> t (ComplexConstraintFam f g a b) bisequenceAComplexConstraintFam = $(makeBisequenceA 'ComplexConstraintFam) $(deriveBifunctor 'UniversalFam) $(deriveBifunctor 'ExistentialListFam) $(deriveBifoldable 'ExistentialFunctorFam) $(deriveBitraversable 'SneakyUseSameNameFam) $(deriveBifunctor 'IntHashFam) $(deriveBifoldable 'IntHashTupleFam) $(deriveBitraversable 'IntHashFam) $(deriveBifunctor 'IntHashFunFam) $(deriveBifunctor 'TyFamily81a) $(deriveBifunctor 'TyFamily82) $(deriveBifoldable 'TyFamily82) $(deriveBitraversable 'TyFamily82) ------------------------------------------------------------------------------- prop_BifunctorLaws :: (Bifunctor p, Eq (p a b), Eq (p c d), Show (p a b), Show (p c d)) => (a -> c) -> (b -> d) -> p a b -> Expectation prop_BifunctorLaws f g x = do bimap id id x `shouldBe` x first id x `shouldBe` x second id x `shouldBe` x bimap f g x `shouldBe` (first f . second g) x prop_BifunctorEx :: (Bifunctor p, Eq (p [Int] [Int]), Show (p [Int] [Int])) => p [Int] [Int] -> Expectation prop_BifunctorEx = prop_BifunctorLaws reverse (++ [42]) prop_BifoldableLaws :: (Eq a, Eq b, Eq z, Show a, Show b, Show z, Monoid a, Monoid b, Bifoldable p) => (a -> b) -> (a -> b) -> (a -> z -> z) -> (a -> z -> z) -> z -> p a a -> Expectation prop_BifoldableLaws f g h i z x = do bifold x `shouldBe` bifoldMap id id x bifoldMap f g x `shouldBe` bifoldr (mappend . f) (mappend . g) mempty x bifoldr h i z x `shouldBe` appEndo (bifoldMap (Endo . h) (Endo . i) x) z prop_BifoldableEx :: Bifoldable p => p [Int] [Int] -> Expectation prop_BifoldableEx = prop_BifoldableLaws reverse (++ [42]) ((+) . length) ((*) . length) 0 prop_BitraversableLaws :: (Applicative f, Applicative g, Bitraversable p, Eq (g (p c c)), Eq (p a b), Eq (p d e), Eq1 f, Show (g (p c c)), Show (p a b), Show (p d e), Show1 f) => (a -> f c) -> (b -> f c) -> (c -> f d) -> (c -> f e) -> (forall x. f x -> g x) -> p a b -> Expectation prop_BitraversableLaws f g h i t x = do bitraverse (t . f) (t . g) x `shouldBe` (t . bitraverse f g) x bitraverse Identity Identity x `shouldBe` Identity x (Compose . fmap (bitraverse h i) . bitraverse f g) x `shouldBe` bitraverse (Compose . fmap h . f) (Compose . fmap i . g) x prop_BitraversableEx :: (Bitraversable p, Eq (p Char Char), Eq (p [Char] [Char]), Eq (p [Int] [Int]), Show (p Char Char), Show (p [Char] [Char]), Show (p [Int] [Int])) => p [Int] [Int] -> Expectation prop_BitraversableEx = prop_BitraversableLaws (replicate 2 . map (chr . abs)) (replicate 4 . map (chr . abs)) (++ "hello") (++ "world") reverse ------------------------------------------------------------------------------- main :: IO () main = hspec spec spec :: Spec spec = do describe "OneTwoCompose Maybe Either [Int] [Int]" $ do prop "satisfies the Bifunctor laws" (prop_BifunctorEx :: OneTwoCompose Maybe Either [Int] [Int] -> Expectation) prop "satisfies the Bifoldable laws" (prop_BifoldableEx :: OneTwoCompose Maybe Either [Int] [Int] -> Expectation) prop "satisfies the Bitraversable laws" (prop_BitraversableEx :: OneTwoCompose Maybe Either [Int] [Int] -> Expectation) describe "OneTwoComposeFam Maybe Either [Int] [Int]" $ do prop "satisfies the Bifunctor laws" (prop_BifunctorEx :: OneTwoComposeFam Maybe Either [Int] [Int] -> Expectation) prop "satisfies the Bifoldable laws" (prop_BifoldableEx :: OneTwoComposeFam Maybe Either [Int] [Int] -> Expectation) prop "satisfies the Bitraversable laws" (prop_BitraversableEx :: OneTwoComposeFam Maybe Either [Int] [Int] -> Expectation) bifunctors-5.6.2/tests/Spec.hs0000644000000000000000000000005407346545000014462 0ustar0000000000000000{-# OPTIONS_GHC -F -pgmF hspec-discover #-} bifunctors-5.6.2/tests/T89Spec.hs0000644000000000000000000000070307346545000014770 0ustar0000000000000000{-# LANGUAGE TemplateHaskell #-} -- | A regression test for #89 which ensures that a TH-generated Bifoldable -- instance of a certain shape does not trigger -Wunused-matches warnings. module T89Spec where import Data.Bifunctor.TH import Test.Hspec data X = MkX data Y a b = MkY a b newtype XY a b = XY { getResp :: Either X (Y a b) } $(deriveBifoldable ''Y) $(deriveBifoldable ''XY) main :: IO () main = hspec spec spec :: Spec spec = return ()