bifunctors 3.0 → 5.6.3
raw patch · 29 files changed
Files
- .travis.yml +0/−1
- CHANGELOG.markdown +276/−0
- LICENSE +1/−5
- README.markdown +13/−0
- bifunctors.cabal +92/−16
- src/Data/Biapplicative.hs +316/−0
- src/Data/Bifoldable.hs +0/−105
- src/Data/Bifunctor.hs +0/−44
- src/Data/Bifunctor/Apply.hs +0/−55
- src/Data/Bifunctor/Biap.hs +116/−0
- src/Data/Bifunctor/Biff.hs +110/−0
- src/Data/Bifunctor/Clown.hs +122/−0
- src/Data/Bifunctor/Fix.hs +77/−0
- src/Data/Bifunctor/Flip.hs +112/−0
- src/Data/Bifunctor/Functor.hs +44/−0
- src/Data/Bifunctor/Join.hs +86/−0
- src/Data/Bifunctor/Joker.hs +126/−0
- src/Data/Bifunctor/Product.hs +138/−0
- src/Data/Bifunctor/Sum.hs +89/−0
- src/Data/Bifunctor/TH.hs +1308/−0
- src/Data/Bifunctor/TH/Internal.hs +448/−0
- src/Data/Bifunctor/Tannen.hs +158/−0
- src/Data/Bifunctor/Wrapped.hs +97/−0
- src/Data/Bitraversable.hs +0/−102
- src/Data/Semigroup/Bifoldable.hs +0/−67
- src/Data/Semigroup/Bitraversable.hs +0/−39
- tests/BifunctorSpec.hs +498/−0
- tests/Spec.hs +1/−0
- tests/T89Spec.hs +21/−0
− .travis.yml
@@ -1,1 +0,0 @@-language: haskell
+ CHANGELOG.markdown view
@@ -0,0 +1,276 @@+5.6.3 [2026.01.03]+------------------+* Allow building with `template-haskell-2.24.*` (GHC 9.14).+* Remove unused dependencies.++5.6.2 [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
LICENSE view
@@ -1,4 +1,4 @@-Copyright 2008-2011 Edward Kmett+Copyright 2008-2016 Edward Kmett All rights reserved. @@ -12,10 +12,6 @@ 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.--3. Neither the name of the author nor the names of his contributors- may be used to endorse or promote products derived from this software- without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ README.markdown view
@@ -0,0 +1,13 @@+bifunctors+==========++[](https://hackage.haskell.org/package/bifunctors) [](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.cabal view
@@ -1,37 +1,113 @@+cabal-version: 1.24 name: bifunctors category: Data, Functors-version: 3.0+version: 5.6.3 license: BSD3-cabal-version: >= 1.6 license-file: LICENSE author: Edward A. Kmett maintainer: Edward A. Kmett <ekmett@gmail.com> stability: provisional homepage: http://github.com/ekmett/bifunctors/ bug-reports: http://github.com/ekmett/bifunctors/issues-copyright: Copyright (C) 2008-2011 Edward A. Kmett-synopsis: Haskell 98 bifunctors-description: Haskell 98 bifunctors+copyright: Copyright (C) 2008-2016 Edward A. Kmett+synopsis: Bifunctors+description: Bifunctors. build-type: Simple-extra-source-files: .travis.yml+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 == 9.6.7+ , GHC == 9.8.4+ , GHC == 9.10.3+ , GHC == 9.12.2+ , GHC == 9.14.1+extra-source-files:+ CHANGELOG.markdown+ README.markdown source-repository head type: git- location: git://github.com/ekmett/bifunctors.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.*,- semigroups >= 0.8.3.1 && < 0.9,- semigroupoids == 3.0.*+ base >= 4.9 && < 5,+ assoc >= 1.1 && < 1.2,+ comonad >= 5.0.7 && < 6,+ containers >= 0.5.7.1 && < 0.9,+ template-haskell >= 2.11 && < 2.25,+ th-abstraction >= 0.4.2.0 && < 0.8 + 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.Bifunctor- Data.Bifunctor.Apply- Data.Bifoldable- Data.Bitraversable- Data.Semigroup.Bifoldable- Data.Semigroup.Bitraversable+ 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
+ src/Data/Biapplicative.hs view
@@ -0,0 +1,316 @@+{-# 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 <ekmett@gmail.com>+-- 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 (<<*>>) #-}
− src/Data/Bifoldable.hs
@@ -1,105 +0,0 @@--------------------------------------------------------------------------------- |--- Module : Data.Bifoldable--- Copyright : (C) 2011 Edward Kmett,--- License : BSD-style (see the file LICENSE)------ Maintainer : Edward Kmett <ekmett@gmail.com>--- Stability : provisional--- Portability : portable---------------------------------------------------------------------------------module Data.Bifoldable - ( Bifoldable(..)- , bifoldr'- , bifoldrM- , bifoldl'- , bifoldlM- , bitraverse_- , bifor_- , bimapM_- , biforM_- , bisequenceA_- , bisequence_- , biList- , biconcat- , biconcatMap- , biany- , biall- ) where--import Control.Applicative-import Data.Monoid--class Bifoldable p where- bifold :: Monoid m => p m m -> m- bifold = bifoldMap id id-- bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> p a b -> m- bifoldMap f g = bifoldr (mappend . f) (mappend . g) mempty-- bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> p a b -> c- bifoldr f g z t = appEndo (bifoldMap (Endo . f) (Endo . g) t) z-- bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> p a b -> c- bifoldl f g z t = appEndo (getDual (bifoldMap (Dual . Endo . flip f) (Dual . Endo . flip g) t)) z--instance Bifoldable (,) where- bifoldMap f g (a, b) = f a `mappend` g b--instance Bifoldable Either where- bifoldMap f _ (Left a) = f a- bifoldMap _ g (Right b) = g b--bifoldr' :: Bifoldable t => (a -> c -> c) -> (b -> c -> c) -> c -> t a b -> c-bifoldr' f g z0 xs = bifoldl f' g' id xs z0 where - f' k x z = k $! f x z- g' k x z = k $! g x z--bifoldrM :: (Bifoldable t, Monad m) => (a -> c -> m c) -> (b -> c -> m c) -> c -> t a b -> m c-bifoldrM f g z0 xs = bifoldl f' g' return xs z0 where- f' k x z = f x z >>= k- g' k x z = g x z >>= k--bifoldl':: Bifoldable t => (a -> b -> a) -> (a -> c -> a) -> a -> t b c -> a-bifoldl' f g z0 xs = bifoldr f' g' id xs z0 where- f' x k z = k $! f z x - g' x k z = k $! g z x--bifoldlM :: (Bifoldable t, Monad m) => (a -> b -> m a) -> (a -> c -> m a) -> a -> t b c -> m a -bifoldlM f g z0 xs = bifoldr f' g' return xs z0 where- f' x k z = f z x >>= k- g' x k z = g z x >>= k- -bitraverse_ :: (Bifoldable t, Applicative f) => (a -> f c) -> (b -> f d) -> t a b -> f ()-bitraverse_ f g = bifoldr ((*>) . f) ((*>) . g) (pure ())--bifor_ :: (Bifoldable t, Applicative f) => t a b -> (a -> f c) -> (b -> f d) -> f ()-bifor_ t f g = bitraverse_ f g t--bimapM_:: (Bifoldable t, Monad m) => (a -> m c) -> (b -> m d) -> t a b -> m ()-bimapM_ f g = bifoldr ((>>) . f) ((>>) . g) (return ())--biforM_ :: (Bifoldable t, Monad m) => t a b -> (a -> m c) -> (b -> m d) -> m ()-biforM_ t f g = bimapM_ f g t--bisequenceA_ :: (Bifoldable t, Applicative f) => t (f a) (f b) -> f ()-bisequenceA_ = bifoldr (*>) (*>) (pure ())--bisequence_ :: (Bifoldable t, Monad m) => t (m a) (m b) -> m ()-bisequence_ = bifoldr (>>) (>>) (return ())--biList :: Bifoldable t => t a a -> [a]-biList = bifoldr (:) (:) []--biconcat :: Bifoldable t => t [a] [a] -> [a]-biconcat = bifold--biconcatMap :: Bifoldable t => (a -> [c]) -> (b -> [c]) -> t a b -> [c]-biconcatMap = bifoldMap --biany :: Bifoldable t => (a -> Bool) -> (b -> Bool) -> t a b -> Bool-biany p q = getAny . bifoldMap (Any . p) (Any . q)--biall :: Bifoldable t => (a -> Bool) -> (b -> Bool) -> t a b -> Bool-biall p q = getAll . bifoldMap (All . p) (All . q)
− src/Data/Bifunctor.hs
@@ -1,44 +0,0 @@--------------------------------------------------------------------------------- |--- Module : Data.Bifunctor--- Copyright : (C) 2008-2011 Edward Kmett,--- License : BSD-style (see the file LICENSE)------ Maintainer : Edward Kmett <ekmett@gmail.com>--- Stability : provisional--- Portability : portable---------------------------------------------------------------------------------module Data.Bifunctor (Bifunctor(..)) where--import Control.Applicative---- | Minimal definition either 'bimap' or 'first' and 'second'-class Bifunctor p where- bimap :: (a -> b) -> (c -> d) -> p a c -> p b d- bimap f g = first f . second g-- first :: (a -> b) -> p a c -> p b c- first f = bimap f id-- second :: (b -> c) -> p a b -> p a c- second = bimap id --instance Bifunctor (,) where- bimap f g (a, b) = (f a, g b)--instance Bifunctor ((,,) x) where- bimap f g (x, a, b) = (x, f a, g b)--instance Bifunctor ((,,,) x y) where- bimap f g (x, y, a, b) = (x, y, f a, g b)--instance Bifunctor ((,,,,) x y z) where- bimap f g (x, y, z, a, b) = (x, y, z, f a, g b)--instance Bifunctor Either where- bimap f _ (Left a) = Left (f a)- bimap _ g (Right b) = Right (g b)--instance Bifunctor Const where- bimap f _ (Const a) = Const (f a)
− src/Data/Bifunctor/Apply.hs
@@ -1,55 +0,0 @@--------------------------------------------------------------------------------- |--- Module : Data.Bifunctor.Apply--- Copyright : (C) 2011 Edward Kmett,--- License : BSD-style (see the file LICENSE)------ Maintainer : Edward Kmett <ekmett@gmail.com>--- Stability : provisional--- Portability : portable---------------------------------------------------------------------------------module Data.Bifunctor.Apply (- -- * Functors- -- * BiAppliable bifunctors- Biapply(..)- , (<<$>>)- , (<<..>>)- , bilift2- , bilift3- , module Data.Bifunctor- ) where--import Data.Bifunctor--infixl 4 <<$>>, <<.>>, <<., .>>, <<..>>--(<<$>>) :: (a -> b) -> a -> b-(<<$>>) = id--class Bifunctor p => Biapply p where- (<<.>>) :: p (a -> b) (c -> d) -> p a c -> p b d-- -- | a .> b = const id <$> a <.> b- (.>>) :: p a b -> p c d -> p c d- a .>> b = bimap (const id) (const id) <<$>> a <<.>> b-- -- | a <. b = const <$> a <.> b- (<<.) :: p a b -> p c d -> p a b- a <<. b = bimap const const <<$>> a <<.>> b--(<<..>>) :: Biapply p => p a c -> p (a -> b) (c -> d) -> p b d-(<<..>>) = bilift2 (flip id) (flip id)---- | Lift binary functions-bilift2 :: Biapply w => (a -> b -> c) -> (d -> e -> f) -> w a d -> w b e -> w c f-bilift2 f g a b = bimap f g <<$>> a <<.>> b-{-# INLINE bilift2 #-}---- | Lift ternary functions-bilift3 :: Biapply w => (a -> b -> c -> d) -> (e -> f -> g -> h) -> w a e -> w b f -> w c g -> w d h-bilift3 f g a b c = bimap f g <<$>> a <<.>> b <<.>> c-{-# INLINE bilift3 #-}--instance Biapply (,) where- (f, g) <<.>> (a, b) = (f a, g b)
+ src/Data/Bifunctor/Biap.hs view
@@ -0,0 +1,116 @@+{-# 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 <ekmett@gmail.com>+-- 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)
+ src/Data/Bifunctor/Biff.hs view
@@ -0,0 +1,110 @@+{-# 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 <ekmett@gmail.com>+-- 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
+ src/Data/Bifunctor/Clown.hs view
@@ -0,0 +1,122 @@+{-# 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 <ekmett@gmail.com>+-- 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 #-}
+ src/Data/Bifunctor/Fix.hs view
@@ -0,0 +1,77 @@+{-# 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 <ekmett@gmail.com>+-- 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 #-}
+ src/Data/Bifunctor/Flip.hs view
@@ -0,0 +1,112 @@+{-# 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 <ekmett@gmail.com>+-- 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
+ src/Data/Bifunctor/Functor.hs view
@@ -0,0 +1,44 @@+{-# 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 #-}
+ src/Data/Bifunctor/Join.hs view
@@ -0,0 +1,86 @@+{-# 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 <ekmett@gmail.com>+-- 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 #-}
+ src/Data/Bifunctor/Joker.hs view
@@ -0,0 +1,126 @@+{-# 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 <ekmett@gmail.com>+-- 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 #-}
+ src/Data/Bifunctor/Product.hs view
@@ -0,0 +1,138 @@+{-# 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 <ekmett@gmail.com>+-- 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)
+ src/Data/Bifunctor/Sum.hs view
@@ -0,0 +1,89 @@+{-# 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)
+ src/Data/Bifunctor/TH.hs view
@@ -0,0 +1,1308 @@+{-# 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 <ekmett@gmail.com>+-- 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
+ src/Data/Bifunctor/TH/Internal.hs view
@@ -0,0 +1,448 @@+{-# 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
+ src/Data/Bifunctor/Tannen.hs view
@@ -0,0 +1,158 @@+{-# 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 <ekmett@gmail.com>+-- 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
+ src/Data/Bifunctor/Wrapped.hs view
@@ -0,0 +1,97 @@+{-# 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 <ekmett@gmail.com>+-- 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 #-}
− src/Data/Bitraversable.hs
@@ -1,102 +0,0 @@--------------------------------------------------------------------------------- |--- Module : Data.Bitraversable--- Copyright : (C) 2011 Edward Kmett,--- License : BSD-style (see the file LICENSE)------ Maintainer : Edward Kmett <ekmett@gmail.com>--- Stability : provisional--- Portability : portable---------------------------------------------------------------------------------module Data.Bitraversable- ( Bitraversable(..)- , bifor- , biforM- , bimapAccumL- , bimapAccumR- , bimapDefault- , bifoldMapDefault- ) where--import Control.Applicative-import Data.Monoid-import Data.Bifunctor-import Data.Bifoldable--class (Bifunctor t, Bifoldable t) => Bitraversable t where- bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> t a b -> f (t c d)- bitraverse f g = bisequenceA . bimap f g-- bisequenceA :: Applicative f => t (f a) (f b) -> f (t a b)- bisequenceA = bitraverse id id-- bimapM :: Monad m => (a -> m c) -> (b -> m d) -> t a b -> m (t c d)- bimapM f g = unwrapMonad . bitraverse (WrapMonad . f) (WrapMonad . g)-- bisequence :: Monad m => t (m a) (m b) -> m (t a b)- bisequence = bimapM id id--instance Bitraversable (,) where- bitraverse f g (a, b) = (,) <$> f a <*> g b--instance Bitraversable Either where- bitraverse f _ (Left a) = Left <$> f a- bitraverse _ g (Right b) = Right <$> g b--bifor :: (Bitraversable t, Applicative f) => t a b -> (a -> f c) -> (b -> f d) -> f (t c d)-bifor t f g = bitraverse f g t-{-# INLINE bifor #-}--biforM :: (Bitraversable t, Monad m) => t a b -> (a -> m c) -> (b -> m d) -> m (t c d)-biforM t f g = bimapM f g t----- left-to-right state transformer-newtype StateL s a = StateL { runStateL :: s -> (s, a) }--instance Functor (StateL s) where- fmap f (StateL k) = StateL $ \ s ->- let (s', v) = k s in (s', f v)--instance Applicative (StateL s) where- pure x = StateL (\ s -> (s, x))- StateL kf <*> StateL kv = StateL $ \ s ->- let (s', f) = kf s- (s'', v) = kv s'- in (s'', f v)--bimapAccumL :: Bitraversable t => (a -> b -> (a, c)) -> (a -> d -> (a, e)) -> a -> t b d -> (a, t c e)-bimapAccumL f g s t = runStateL (bitraverse (StateL . flip f) (StateL . flip g) t) s---- right-to-left state transformer-newtype StateR s a = StateR { runStateR :: s -> (s, a) }--instance Functor (StateR s) where- fmap f (StateR k) = StateR $ \ s ->- let (s', v) = k s in (s', f v)--instance Applicative (StateR s) where- pure x = StateR (\ s -> (s, x))- StateR kf <*> StateR kv = StateR $ \ s ->- let (s', v) = kv s- (s'', f) = kf s'- in (s'', f v)--bimapAccumR :: Bitraversable t => (a -> b -> (a, c)) -> (a -> d -> (a, e)) -> a -> t b d -> (a, t c e)-bimapAccumR f g s t = runStateR (bitraverse (StateR . flip f) (StateR . flip g) t) s--newtype Id a = Id { getId :: a }--instance Functor Id where- fmap f (Id x) = Id (f x)--instance Applicative Id where- pure = Id- Id f <*> Id x = Id (f x)--bimapDefault :: Bitraversable t => (a -> b) -> (c -> d) -> t a c -> t b d-bimapDefault f g = getId . bitraverse (Id . f) (Id . g)--bifoldMapDefault :: (Bitraversable t, Monoid m) => (a -> m) -> (b -> m) -> t a b -> m -bifoldMapDefault f g = getConst . bitraverse (Const . f) (Const . g)
− src/Data/Semigroup/Bifoldable.hs
@@ -1,67 +0,0 @@--------------------------------------------------------------------------------- |--- Module : Data.Semigroup.Foldable--- Copyright : (C) 2011 Edward Kmett--- License : BSD-style (see the file LICENSE)------ Maintainer : Edward Kmett <ekmett@gmail.com>--- Stability : provisional--- Portability : portable---------------------------------------------------------------------------------module Data.Semigroup.Bifoldable- ( Bifoldable1(..)- , bitraverse1_- , bifor1_- , bisequenceA1_- , bifoldMapDefault1- ) where--import Prelude hiding (foldr)-import Data.Bifoldable-import Data.Functor.Apply-import Data.Semigroup--class Bifoldable t => Bifoldable1 t where- bifold1 :: Semigroup m => t m m -> m- bifold1 = bifoldMap1 id id-- bifoldMap1 :: Semigroup m => (a -> m) -> (b -> m) -> t a b -> m- bifoldMap1 f g = maybe (error "bifoldMap1") id . getOption . bifoldMap (Option . Just . f) (Option . Just . g)--instance Bifoldable1 Either where- bifoldMap1 f _ (Left a) = f a- bifoldMap1 _ g (Right b) = g b--instance Bifoldable1 (,) where- bifoldMap1 f g (a, b) = f a <> g b--newtype Act f a = Act { getAct :: f a }--instance Apply f => Semigroup (Act f a) where- Act a <> Act b = Act (a .> b)--instance Functor f => Functor (Act f) where- fmap f (Act a) = Act (f <$> a)- b <$ Act a = Act (b <$ a)--bitraverse1_ :: (Bifoldable1 t, Apply f) => (a -> f b) -> (c -> f d) -> t a c -> f ()-bitraverse1_ f g t = getAct (bifoldMap1 (Act . ignore . f) (Act . ignore . g) t)-{-# INLINE bitraverse1_ #-}--bifor1_ :: (Bifoldable1 t, Apply f) => t a c -> (a -> f b) -> (c -> f d) -> f ()-bifor1_ t f g = bitraverse1_ f g t -{-# INLINE bifor1_ #-}--ignore :: Functor f => f a -> f ()-ignore = (() <$)--bisequenceA1_ :: (Bifoldable1 t, Apply f) => t (f a) (f b) -> f ()-bisequenceA1_ t = getAct (bifoldMap1 (Act . ignore) (Act . ignore) t)-{-# INLINE bisequenceA1_ #-}---- | Usable default for foldMap, but only if you define bifoldMap1 yourself-bifoldMapDefault1 :: (Bifoldable1 t, Monoid m) => (a -> m) -> (b -> m) -> t a b -> m-bifoldMapDefault1 f g = unwrapMonoid . bifoldMap (WrapMonoid . f) (WrapMonoid . g)-{-# INLINE bifoldMapDefault1 #-}-
− src/Data/Semigroup/Bitraversable.hs
@@ -1,39 +0,0 @@--------------------------------------------------------------------------------- |--- Module : Data.Semigroup.Bitraversable--- Copyright : (C) 2011 Edward Kmett--- License : BSD-style (see the file LICENSE)------ Maintainer : Edward Kmett <ekmett@gmail.com>--- Stability : provisional--- Portability : portable---------------------------------------------------------------------------------module Data.Semigroup.Bitraversable- ( Bitraversable1(..)- , bifoldMap1Default- ) where--import Control.Applicative-import Data.Functor.Apply-import Data.Semigroup.Bifoldable-import Data.Bitraversable-import Data.Bifunctor-import Data.Semigroup--class (Bifoldable1 t, Bitraversable t) => Bitraversable1 t where- bitraverse1 :: Apply f => (a -> f b) -> (c -> f d) -> t a c -> f (t b d)- bitraverse1 f g = bisequence1 . bimap f g-- bisequence1 :: Apply f => t (f a) (f b) -> f (t a b)- bisequence1 = bitraverse1 id id--bifoldMap1Default :: (Bitraversable1 t, Semigroup m) => (a -> m) -> (b -> m) -> t a b -> m-bifoldMap1Default f g = getConst . bitraverse1 (Const . f) (Const . g)--instance Bitraversable1 Either where- bitraverse1 f _ (Left a) = Left <$> f a- bitraverse1 _ g (Right b) = Right <$> g b--instance Bitraversable1 (,) where- bitraverse1 f g (a, b) = (,) <$> f a <.> g b
+ tests/BifunctorSpec.hs view
@@ -0,0 +1,498 @@+{-# 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)
+ tests/Spec.hs view
@@ -0,0 +1,1 @@+{-# OPTIONS_GHC -F -pgmF hspec-discover #-}
+ tests/T89Spec.hs view
@@ -0,0 +1,21 @@+{-# 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 ()