generic-lens-lite (empty) → 0.1
raw patch · 5 files changed
+433/−0 lines, 5 filesdep +basedep +generic-lens-lite
Dependencies added: base, generic-lens-lite
Files
- LICENSE +30/−0
- example/Example.hs +51/−0
- generic-lens-lite.cabal +54/−0
- src/Data/Functor/Confusing.hs +146/−0
- src/Data/Generics/Lens/Lite.hs +152/−0
+ LICENSE view
@@ -0,0 +1,30 @@+Copyright (c) 2020 Oleg Grenrus++All rights reserved.++Redistribution and use in source and binary forms, with or without+modification, are permitted provided that the following conditions are met:++ * Redistributions of source code must retain the above copyright+ notice, this list of conditions and the following disclaimer.++ * 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.++ * Neither the name of Oleg Grenrus nor the names of other+ contributors may be used to endorse or promote products derived+ from this software without specific prior written permission.++THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ example/Example.hs view
@@ -0,0 +1,51 @@+{-# LANGUAGE DataKinds #-}+{-# LANGUAGE DeriveGeneric #-}+{-# LANGUAGE TypeApplications #-}+{-# OPTIONS_GHC -funfolding-keeness-factor=100 #-}+module Main (module Main) where++import Data.Generics.Lens.Lite (field)+import GHC.Generics (Generic)++main :: IO ()+main = return ()++-------------------------------------------------------------------------------+-- Big record+-------------------------------------------------------------------------------++data Ex = Ex+ { exA :: Int+ , exB :: Bool+ , ex0 :: Char+ , ex1 :: Char+ , ex2 :: Char+ , ex3 :: Char+ , ex4 :: Char+ , ex5 :: Char+ , ex6 :: Char+ , ex7 :: Char+ , ex8 :: Char+ , ex9 :: Char+ } deriving (Generic)++_exA :: Functor f => (Int -> f Int) -> Ex -> f Ex+_exA = field @"exA"++_exB :: Functor f => (Bool -> f Bool) -> Ex -> f Ex+_exB = field @"exB"++_ex4 :: Functor f => (Char -> f Char) -> Ex -> f Ex+_ex4 = field @"ex4"++-------------------------------------------------------------------------------+-- Sum of records+-------------------------------------------------------------------------------++data Ex2+ = Ex2A { exC :: Char }+ | Ex2B { exC :: Char }+ deriving (Generic)++_exC :: Functor f => (Char -> f Char) -> Ex2 -> f Ex2+_exC = field @"exC"
+ generic-lens-lite.cabal view
@@ -0,0 +1,54 @@+cabal-version: 2.2+name: generic-lens-lite+version: 0.1+synopsis: Monomorphic field lens like with generic-lens+category: Lens, Generics+description:+ Derivation of (monomorphic, i.e. not type-changing) lens, like generic-lens.+ .+ The package have minimal dependecies and minimal API:+ .+ @+ class HasField (name :: Symbol) r a | name r -> a+ field :: HasField name r a => Lens' r a+ @++homepage: https://github.com/phadej/generic-lens-lite+license: BSD-3-Clause+license-file: LICENSE+author: Edward Kmett, Csongor Kiss, Oleg Grenrus+maintainer: Oleg Grenrus <oleg.grenrus@iki.fi>+copyright: Copyright (c) 2019 Edward Kmett, 2020 Oleg Grenrus+build-type: Simple+tested-with: GHC ==8.0.2 || ==8.2.2 || ==8.4.4 || ==8.6.5 || ==8.8.1++source-repository head+ type: git+ location: https://github.com/phadej/generic-lens-lite+ subdir: generic-lens-lite++library+ default-language: Haskell2010+ hs-source-dirs: src+ ghc-options: -Wall+ exposed-modules: Data.Generics.Lens.Lite+ other-modules: Data.Functor.Confusing+ build-depends: base >=4.9 && <4.14++ if impl(ghc >=8.4)+ ghc-options:+ -Wincomplete-uni-patterns -Wincomplete-record-updates+ -Wredundant-constraints -Widentities -Wmissing-export-lists++test-suite example+ type: exitcode-stdio-1.0+ default-language: Haskell2010+ hs-source-dirs: example+ main-is: Example.hs+ ghc-options: -Wall+ build-depends:+ , base+ , generic-lens-lite++-- build-depends: dump-core+-- ghc-options: -fplugin=DumpCore
+ src/Data/Functor/Confusing.hs view
@@ -0,0 +1,146 @@+{-# LANGUAGE RankNTypes #-}+{-# LANGUAGE Safe #-}+-- |+-- Csongor Kiss, Matthew Pickering, and Nicolas Wu. 2018. Generic deriving of generic traversals.+-- Proc. ACM Program. Lang. 2, ICFP, Article 85 (July 2018), 30 pages. DOI: https://doi.org/10.1145/3236780+--+-- https://arxiv.org/abs/1805.06798+--+-- This is modified version of part of @generic-lens@ library+--+-- Copyright (c) 2018, Csongor Kiss+--+-- All rights reserved.+--+-- Redistribution and use in source and binary forms, with or without+-- modification, are permitted provided that the following conditions are met:+--+-- * Redistributions of source code must retain the above copyright+-- notice, this list of conditions and the following disclaimer.+--+-- * 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.+--+-- * Neither the name of Csongor Kiss nor the names of other+-- contributors may be used to endorse or promote products derived+-- from this software without specific prior written permission.+--+-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS+-- "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT+-- LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR+-- A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT+-- OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,+-- SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT+-- LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,+-- DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY+-- THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT+-- (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE+-- OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.+--+module Data.Functor.Confusing (+ fusing, confusing, LensLike,+ ifusing, iconfusing, IxLensLike,+ ffusing, fconfusing, FLensLike,+ CurriedYoneda, lowerCurriedYoneda, liftCurriedYoneda, yap,+ Curried (..), liftCurried, lowerCurried,+ Yoneda (..), liftYoneda, lowerYoneda,+ ) where++import Control.Applicative++-------------------------------------------------------------------------------+-- Confusing+-------------------------------------------------------------------------------++type LensLike f s t a b = (a -> f b) -> s -> f t++-- note: qualified name to justify import even with newer GHCs++fusing :: Functor f => LensLike (Yoneda f) s t a b -> LensLike f s t a b+fusing t = \f -> lowerYoneda . t (liftYoneda . f)+{-# INLINE fusing #-}++confusing :: Control.Applicative.Applicative f => LensLike (Curried (Yoneda f)) s t a b -> LensLike f s t a b+confusing t = \f -> lowerCurriedYoneda . t (liftCurriedYoneda . f)+{-# INLINE confusing #-}++type IxLensLike f i s t a b = (i -> a -> f b) -> s -> f t++ifusing :: Functor f => IxLensLike (Yoneda f) i s t a b -> IxLensLike f i s t a b+ifusing t = \f -> lowerYoneda . t (\i a -> liftYoneda (f i a))+{-# INLINE ifusing #-}++iconfusing :: Applicative f => IxLensLike (Curried (Yoneda f)) i s t a b -> IxLensLike f i s t a b+iconfusing t = \f -> lowerYoneda . lowerCurried . t (\i a -> liftCurriedYoneda (f i a))+{-# INLINE iconfusing #-}++type FLensLike f s t a b = (forall x. a x -> f (b x)) -> s -> f t++ffusing :: Functor f => FLensLike (Yoneda f) s t a b -> FLensLike f s t a b+ffusing t = \f -> lowerYoneda . t (liftYoneda . f)+{-# INLINE ffusing #-}++fconfusing :: Applicative f => FLensLike (Curried (Yoneda f)) s t a b -> FLensLike f s t a b+fconfusing t = \f -> lowerYoneda . lowerCurried . t (liftCurriedYoneda . f)+{-# INLINE fconfusing #-}++-------------------------------------------------------------------------------+-- CurriedYoneda+-------------------------------------------------------------------------------++type CurriedYoneda f = Curried (Yoneda f)++lowerCurriedYoneda :: Applicative f => Curried (Yoneda f) a -> f a+lowerCurriedYoneda = lowerYoneda . lowerCurried+{-# INLINE lowerCurriedYoneda #-}++liftCurriedYoneda :: Applicative f => f a -> Curried (Yoneda f) a+liftCurriedYoneda fa = Curried (`yap` fa)+{-# INLINE liftCurriedYoneda #-}++yap :: Applicative f => Yoneda f (a -> b) -> f a -> Yoneda f b+yap (Yoneda k) fa = Yoneda (\ab_r -> k (ab_r .) <*> fa)+{-# INLINE yap #-}++-------------------------------------------------------------------------------+-- Curried+-------------------------------------------------------------------------------++newtype Curried f a = Curried { runCurried :: forall r. f (a -> r) -> f r }++instance Functor f => Functor (Curried f) where+ fmap f (Curried g) = Curried (g . fmap (.f))+ {-# INLINE fmap #-}++instance Functor f => Applicative (Curried f) where+ pure a = Curried (fmap ($ a))+ {-# INLINE pure #-}+ Curried mf <*> Curried ma = Curried (ma . mf . fmap (.))+ {-# INLINE (<*>) #-}++liftCurried :: Applicative f => f a -> Curried f a+liftCurried fa = Curried (<*> fa)++lowerCurried :: Applicative f => Curried f a -> f a+lowerCurried (Curried f) = f (pure id)++-------------------------------------------------------------------------------+-- Yoneda+-------------------------------------------------------------------------------++newtype Yoneda f a = Yoneda { runYoneda :: forall b. (a -> b) -> f b }++liftYoneda :: Functor f => f a -> Yoneda f a+liftYoneda a = Yoneda (\f -> fmap f a)++lowerYoneda :: Yoneda f a -> f a+lowerYoneda (Yoneda f) = f id++instance Functor (Yoneda f) where+ fmap f m = Yoneda (\k -> runYoneda m (k . f))++instance Applicative f => Applicative (Yoneda f) where+ pure a = Yoneda (\f -> pure (f a))+ Yoneda m <*> Yoneda n = Yoneda (\f -> m (f .) <*> n id)
+ src/Data/Generics/Lens/Lite.hs view
@@ -0,0 +1,152 @@+{-# LANGUAGE AllowAmbiguousTypes #-}+{-# LANGUAGE DataKinds #-}+{-# LANGUAGE EmptyCase #-}+{-# LANGUAGE FlexibleContexts #-}+{-# LANGUAGE FlexibleInstances #-}+{-# LANGUAGE FunctionalDependencies #-}+{-# LANGUAGE ScopedTypeVariables #-}+{-# LANGUAGE TypeFamilies #-}+{-# LANGUAGE TypeOperators #-}+{-# LANGUAGE UndecidableInstances #-}+{-# OPTIONS_GHC -Wno-redundant-constraints #-}+-- | Derive record field lenses generically.+module Data.Generics.Lens.Lite (+ field,+ HasField,+ ) where++import Data.Functor.Confusing (LensLike, Yoneda, fusing)+import Data.Kind (Constraint, Type)+import Data.Proxy (Proxy (..))+import GHC.TypeLits (ErrorMessage (..), Symbol, TypeError)++import GHC.Generics++-------------------------------------------------------------------------------+-- Public API+-------------------------------------------------------------------------------++-- | Type-class restricting 'field' usage.+class HasField (name :: Symbol) r a | name r -> a where+ field__ :: Proxy name -> LensLikeYoneda' f r a++class HasFieldInternal (name :: Symbol) r a | name r -> a where+ field_ :: Proxy name -> LensLikeYoneda' f r a++-- | A lens that focuses on a field with a given name.+-- Compatible with the lens package's 'Control.Lens.Lens' type.+--+-- __Note:__ the lens is /simple/, i.e. doesn't allow type-changing updates.+-- This keeps the implementation small and quick.+--+-- You also may want to specify+-- @+-- {-\# OPTIONS_GHC -funfolding-keeness-factor=100 #-} (or some other arbitrarily large number)+-- @+-- for GHC to inline more aggressively.+--+field+ :: forall (name :: Symbol) (r :: Type) (a :: Type) (f :: Type -> Type). (HasField name r a, Functor f)+ => (a -> f a) -> r -> f r+field = fusing (field__ (Proxy :: Proxy name))++instance HasFieldInternal name r a => HasField name r a where+ field__ = field_+ {-# INLINE field__ #-}++instance+ ( Generic r+ , ErrorCheck name r a (HasFieldPred name (Rep r))+ , HasFieldPred name (Rep r) ~ 'Just a+ , GField name (Rep r) a+ ) => HasFieldInternal name r a+ where+ field_ pname f s = fmap to (gfield pname f (from s))+ {-# INLINE field_ #-}++-------------------------------------------------------------------------------+-- Errors+-------------------------------------------------------------------------------++type family ErrorCheck (name :: Symbol) r a (res :: Maybe Type) :: Constraint where+ ErrorCheck _ _ _ ('Just _) = ()+ ErrorCheck name r a 'Nothing = TypeError+ ( 'Text "Type " ':<>: 'ShowType r+ ':<>: 'Text " doesn't have field named " ':<>: 'Text name+ )++-- this prevents expansion of HasField "alias".+data Void1 a++instance {-# OVERLAPPING #-} HasField name (Void1 a) a where+ field__ _ _ n = case n of {}++-------------------------------------------------------------------------------+-- Generics+-------------------------------------------------------------------------------++type LensLikeYoneda' f r a = LensLike (Yoneda f) r r a a++class (HasFieldPred name f ~ 'Just a) => GField (name :: Symbol) f a | name f -> a where+ gfield :: Proxy name -> LensLikeYoneda' h (f ()) a++instance (GFieldSum name f a, i ~ D, HasFieldPred name f ~ 'Just a) => GField name (M1 i c f) a where+ gfield pname f (M1 x) = fmap M1 (gfieldsum pname f x)+ {-# INLINE gfield #-}++class HasFieldPred name f ~ 'Just a => GFieldSum (name :: Symbol) f a | name f -> a where+ gfieldsum :: Proxy name -> LensLikeYoneda' h (f ()) a++instance (HasFieldPred name (f :+: g) ~ 'Just a, GFieldSum name f a, GFieldSum name g a) => GFieldSum name (f :+: g) a where+ gfieldsum pname f (L1 x) = fmap L1 (gfieldsum pname f x)+ gfieldsum pname f (R1 y) = fmap R1 (gfieldsum pname f y)+ {-# INLINE gfieldsum #-}++instance (GFieldProd name f a, i ~ C, HasFieldPred name f ~ 'Just a) => GFieldSum name (M1 i c f) a where+ gfieldsum pname f (M1 x) = fmap M1 (gfieldprod pname f x)+ {-# INLINE gfieldsum #-}++class (HasFieldPred name f ~ 'Just a) => GFieldProd (name :: Symbol) f a | name f -> a where+ gfieldprod :: Proxy name -> LensLikeYoneda' h (f ()) a++instance (c ~ 'MetaSel ('Just name) u s l, f ~ Rec0 a, i ~ S) => GFieldProd name (M1 i c f) a where+ gfieldprod _ f (M1 (K1 x)) = fmap (M1 . K1) (f x)+ {-# INLINE gfieldprod #-}++instance GFieldProd' name f g (HasFieldPred name f) a => GFieldProd name (f :*: g) a where+ gfieldprod = gfieldprod' (Proxy :: Proxy (HasFieldPred name f))+ {-# INLINE gfieldprod #-}++class (HasFieldPred name (f :*: g) ~ 'Just a) => GFieldProd' (name :: Symbol) f g (res :: Maybe Type) a where+ gfieldprod' :: Proxy res -> Proxy name -> LensLikeYoneda' h ((f :*: g) ()) a++instance (a ~ a', GFieldProd name f a', HasFieldPred name (f :*: g) ~ 'Just a) => GFieldProd' name f g ('Just a') a where+ gfieldprod' _ pname f (x :*: y) = fmap (:*: y) (gfieldprod pname f x)+ {-# INLINE gfieldprod' #-}++instance (a ~ a', GFieldProd name g a', HasFieldPred name (f :*: g) ~ 'Just a) => GFieldProd' name f g 'Nothing a where+ gfieldprod' _ pname f (x :*: y) = fmap (x :*:) (gfieldprod pname f y)+ {-# INLINE gfieldprod' #-}++-------------------------------------------------------------------------------+-- TotalField+-------------------------------------------------------------------------------++type family Both (m1 :: Maybe Type) (m2 :: Maybe Type) :: Maybe Type where+ Both ('Just a) ('Just a) = 'Just a++type family Alt (m1 :: Maybe Type) (m2 :: Maybe Type) :: Maybe Type where+ Alt ('Just a) _ = 'Just a+ Alt _ b = b++type family HasFieldPred (field :: Symbol) f :: Maybe Type where+ HasFieldPred field (S1 ('MetaSel ('Just field) _ _ _) (Rec0 t)) =+ 'Just t+ HasFieldPred field (S1 _ _) = 'Nothing+ HasFieldPred field (l :*: r) = Alt (HasFieldPred field l) (HasFieldPred field r)+ HasFieldPred field (l :+: r) = Both (HasFieldPred field l) (HasFieldPred field r)+ HasFieldPred field (C1 _ f) = HasFieldPred field f+ HasFieldPred field (D1 _ f) = HasFieldPred field f+ HasFieldPred field (K1 _ _) = 'Nothing+ HasFieldPred field U1 = 'Nothing+ HasFieldPred field V1 = 'Nothing