diff --git a/.hlint.yaml b/.hlint.yaml new file mode 100644 --- /dev/null +++ b/.hlint.yaml @@ -0,0 +1,2 @@ +- ignore: {name: Unused LANGUAGE pragma} +- ignore: {name: Avoid lambda} diff --git a/.travis.yml b/.travis.yml deleted file mode 100644 --- a/.travis.yml +++ /dev/null @@ -1,161 +0,0 @@ -# This Travis job script has been generated by a script via -# -# runghc make_travis_yml_2.hs '-o' '.travis.yml' '--ghc-head' '--jobs=2' '--irc-channel=irc.freenode.org#haskell-lens' '--no-no-tests-no-bench' '--no-install-dependencies' 'cabal.project' -# -# For more information, see https://github.com/hvr/multi-ghc-travis -# -language: c -sudo: false - -git: - submodules: false # whether to recursively clone submodules - -notifications: - irc: - channels: - - "irc.freenode.org#haskell-lens" - skip_join: true - template: - - "\x0313reflection\x03/\x0306%{branch}\x03 \x0314%{commit}\x03 %{build_url} %{message}" - -cache: - directories: - - $HOME/.cabal/packages - - $HOME/.cabal/store - -before_cache: - - rm -fv $HOME/.cabal/packages/hackage.haskell.org/build-reports.log - # remove files that are regenerated by 'cabal update' - - rm -fv $HOME/.cabal/packages/hackage.haskell.org/00-index.* - - rm -fv $HOME/.cabal/packages/hackage.haskell.org/*.json - - rm -fv $HOME/.cabal/packages/hackage.haskell.org/01-index.cache - - rm -fv $HOME/.cabal/packages/hackage.haskell.org/01-index.tar - - rm -fv $HOME/.cabal/packages/hackage.haskell.org/01-index.tar.idx - - - rm -rfv $HOME/.cabal/packages/head.hackage - -matrix: - include: - - compiler: "ghc-8.6.1" - env: GHCHEAD=true - addons: {apt: {packages: [ghc-ppa-tools,cabal-install-head,ghc-8.6.1], sources: [hvr-ghc]}} - - compiler: "ghc-8.4.3" - # env: TEST=--disable-tests BENCH=--disable-benchmarks - addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.2,ghc-8.4.3], sources: [hvr-ghc]}} - - compiler: "ghc-8.2.2" - # env: TEST=--disable-tests BENCH=--disable-benchmarks - addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.2,ghc-8.2.2], sources: [hvr-ghc]}} - - compiler: "ghc-8.0.2" - # env: TEST=--disable-tests BENCH=--disable-benchmarks - addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.2,ghc-8.0.2], sources: [hvr-ghc]}} - - compiler: "ghc-7.10.3" - # env: TEST=--disable-tests BENCH=--disable-benchmarks - addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.2,ghc-7.10.3], sources: [hvr-ghc]}} - - compiler: "ghc-7.8.4" - # env: TEST=--disable-tests BENCH=--disable-benchmarks - addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.2,ghc-7.8.4], sources: [hvr-ghc]}} - - compiler: "ghc-7.6.3" - # env: TEST=--disable-tests BENCH=--disable-benchmarks - addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.2,ghc-7.6.3], sources: [hvr-ghc]}} - - compiler: "ghc-7.4.2" - # env: TEST=--disable-tests BENCH=--disable-benchmarks - addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.2,ghc-7.4.2], sources: [hvr-ghc]}} - - compiler: "ghc-7.2.2" - # env: TEST=--disable-tests BENCH=--disable-benchmarks - addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.2,ghc-7.2.2], sources: [hvr-ghc]}} - - compiler: "ghc-7.0.4" - # env: TEST=--disable-tests BENCH=--disable-benchmarks - addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.2,ghc-7.0.4], sources: [hvr-ghc]}} - - compiler: "ghc-head" - env: GHCHEAD=true - addons: {apt: {packages: [ghc-ppa-tools,cabal-install-head,ghc-head], sources: [hvr-ghc]}} - - allow_failures: - - compiler: "ghc-head" - - compiler: "ghc-7.0.4" - - compiler: "ghc-7.2.2" - - compiler: "ghc-8.6.1" - -before_install: - - HC=${CC} - - HCPKG=${HC/ghc/ghc-pkg} - - unset CC - - ROOTDIR=$(pwd) - - mkdir -p $HOME/.local/bin - - "PATH=/opt/ghc/bin:/opt/ghc-ppa-tools/bin:$HOME/local/bin:$PATH" - - HCNUMVER=$(( $(${HC} --numeric-version|sed -E 's/([0-9]+)\.([0-9]+)\.([0-9]+).*/\1 * 10000 + \2 * 100 + \3/') )) - - echo $HCNUMVER - -install: - - cabal --version - - echo "$(${HC} --version) [$(${HC} --print-project-git-commit-id 2> /dev/null || echo '?')]" - - BENCH=${BENCH---enable-benchmarks} - - TEST=${TEST---enable-tests} - - HADDOCK=${HADDOCK-true} - - UNCONSTRAINED=${UNCONSTRAINED-true} - - NOINSTALLEDCONSTRAINTS=${NOINSTALLEDCONSTRAINTS-false} - - GHCHEAD=${GHCHEAD-false} - - travis_retry cabal update -v - - "sed -i.bak 's/^jobs:/-- jobs:/' ${HOME}/.cabal/config" - - rm -fv cabal.project cabal.project.local - - "sed -i.bak 's/^-- jobs:.*/jobs: 2/' ${HOME}/.cabal/config" - # Overlay Hackage Package Index for GHC HEAD: https://github.com/hvr/head.hackage - - | - if $GHCHEAD; then - sed -i 's/-- allow-newer: .*/allow-newer: *:base/' ${HOME}/.cabal/config - for pkg in $($HCPKG list --simple-output); do pkg=$(echo $pkg | sed 's/-[^-]*$//'); sed -i "s/allow-newer: /allow-newer: *:$pkg, /" ${HOME}/.cabal/config; done - - echo 'repository head.hackage' >> ${HOME}/.cabal/config - echo ' url: http://head.hackage.haskell.org/' >> ${HOME}/.cabal/config - echo ' secure: True' >> ${HOME}/.cabal/config - echo ' root-keys: 07c59cb65787dedfaef5bd5f987ceb5f7e5ebf88b904bbd4c5cbdeb2ff71b740' >> ${HOME}/.cabal/config - echo ' 2e8555dde16ebd8df076f1a8ef13b8f14c66bad8eafefd7d9e37d0ed711821fb' >> ${HOME}/.cabal/config - echo ' 8f79fd2389ab2967354407ec852cbe73f2e8635793ac446d09461ffb99527f6e' >> ${HOME}/.cabal/config - echo ' key-threshold: 3' >> ${HOME}/.cabal.config - - grep -Ev -- '^\s*--' ${HOME}/.cabal/config | grep -Ev '^\s*$' - - cabal new-update head.hackage -v - fi - - grep -Ev -- '^\s*--' ${HOME}/.cabal/config | grep -Ev '^\s*$' - - "printf 'packages: \".\"\\n' > cabal.project" - - touch cabal.project.local - - "if ! $NOINSTALLEDCONSTRAINTS; then for pkg in $($HCPKG list --simple-output); do echo $pkg | sed 's/^/constraints: /' | sed 's/-[^-]*$/ installed/' >> cabal.project.local; done; fi" - - cat cabal.project || true - - cat cabal.project.local || true - - if [ -f "./configure.ac" ]; then - (cd "." && autoreconf -i); - fi - - rm -f cabal.project.freeze - - rm -rf .ghc.environment.* "."/dist - - DISTDIR=$(mktemp -d /tmp/dist-test.XXXX) - -# Here starts the actual work to be performed for the package under test; -# any command which exits with a non-zero exit code causes the build to fail. -script: - # test that source-distributions can be generated - - (cd "." && cabal sdist) - - mv "."/dist/reflection-*.tar.gz ${DISTDIR}/ - - cd ${DISTDIR} || false - - find . -maxdepth 1 -name '*.tar.gz' -exec tar -xvf '{}' \; - - "printf 'packages: reflection-*/*.cabal\\n' > cabal.project" - - touch cabal.project.local - - "if ! $NOINSTALLEDCONSTRAINTS; then for pkg in $($HCPKG list --simple-output); do echo $pkg | sed 's/^/constraints: /' | sed 's/-[^-]*$/ installed/' >> cabal.project.local; done; fi" - - cat cabal.project || true - - cat cabal.project.local || true - - # build & run tests, build benchmarks - - cabal new-build -w ${HC} ${TEST} ${BENCH} all - - # cabal check - - (cd reflection-* && cabal check) - - # haddock - - rm -rf ./dist-newstyle - - if $HADDOCK; then cabal new-haddock -w ${HC} ${TEST} ${BENCH} all; else echo "Skipping haddock generation";fi - - # Build without installed constraints for packages in global-db - - if $UNCONSTRAINED; then rm -f cabal.project.local; echo cabal new-build -w ${HC} --disable-tests --disable-benchmarks all; else echo "Not building without installed constraints"; fi - -# REGENDATA ["-o",".travis.yml","--ghc-head","--jobs=2","--irc-channel=irc.freenode.org#haskell-lens","--no-no-tests-no-bench","--no-install-dependencies","cabal.project"] -# EOF diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown --- a/CHANGELOG.markdown +++ b/CHANGELOG.markdown @@ -1,3 +1,23 @@ +# 2.1.9 [2024.12.04] +* Drop support for pre-8.0 versions of GHC. + +# 2.1.8 [2024.05.04] +* Fix a memory leak in `reifyTypeable`. + +# 2.1.7 [2023.02.28] +* When building with `base-4.18` (GHC 9.6) or later, implement `reifyNat` and + `reifySymbol` using the API provided by `GHC.TypeLits` instead of resorting + to `unsafeCoerce`. + +# 2.1.6 [2020.05.16] +* Fix a bug in which `give` (and possibly `reify`, `reifyNat`, and + `reifySymbol`) could be unsoundly inlined by GHC 8.10 or older to produce + incorrect runtime results. + +# 2.1.5 [2019.08.27] +* Fix a bug in which `reifyNat` would yield incorrect results for very large + `Integer`s on GHC 8.2 or later. + # 2.1.4 [2018.07.02] * Allow building with GHC 8.6. diff --git a/README.markdown b/README.markdown --- a/README.markdown +++ b/README.markdown @@ -1,7 +1,7 @@ reflection ========== -[![Hackage](https://img.shields.io/hackage/v/reflection.svg)](https://hackage.haskell.org/package/reflection) [![Build Status](https://secure.travis-ci.org/ekmett/reflection.png?branch=master)](http://travis-ci.org/ekmett/reflection) +[![Hackage](https://img.shields.io/hackage/v/reflection.svg)](https://hackage.haskell.org/package/reflection) [![Build Status](https://github.com/ekmett/reflection/workflows/Haskell-CI/badge.svg)](https://github.com/ekmett/reflection/actions?query=workflow%3AHaskell-CI) This package provides an implementation of the ideas presented in [Functional Pearl: Implicit Configurations](http://okmij.org/ftp/Haskell/tr-15-04.pdf) by Oleg Kiselyov and Chung-Chieh Shan. However, the API has been implemented in a much more efficient manner. diff --git a/examples/Constraints.hs b/examples/Constraints.hs --- a/examples/Constraints.hs +++ b/examples/Constraints.hs @@ -1,21 +1,24 @@ -{-# LANGUAGE Rank2Types, TypeFamilies, TypeOperators, ConstraintKinds, PolyKinds, FlexibleInstances, MultiParamTypeClasses, ScopedTypeVariables, FlexibleContexts, UndecidableInstances #-} +{-# LANGUAGE Rank2Types, TypeFamilies, TypeOperators, ConstraintKinds, PolyKinds, FlexibleInstances, MultiParamTypeClasses, ScopedTypeVariables, FlexibleContexts, UndecidableInstances, CPP #-} module Constraints where -import Control.Newtype -- from newtype -import Data.Constraint -- from constraints -import Data.Constraint.Unsafe -- from constraints -import Data.Monoid -- from base -import Data.Proxy -- from tagged -import Data.Reflection -- from reflection +import Control.Newtype.Generics -- from newtype-generics +import Data.Constraint -- from constraints +import Data.Constraint.Unsafe -- from constraints +import Data.Proxy -- from tagged +import Data.Reflection -- from reflection +#if !(MIN_VERSION_base(4,11,0)) +import Data.Semigroup -- from semigroups +#endif --- | Values in our dynamically constructed monoid over 'a' +-- | Values in our dynamically constructed monoid over @a@ newtype Lift (p :: * -> Constraint) (a :: *) (s :: *) = Lift { lower :: a } class ReifiableConstraint p where data Def (p :: * -> Constraint) (a :: *) reifiedIns :: Reifies s (Def p a) :- p (Lift p a s) -instance Newtype (Lift p a s) a where +instance Newtype (Lift p a s) where + type O (Lift p a s) = a pack = Lift unpack = lower @@ -42,8 +45,11 @@ data Def Monoid a = Monoid { mappend_ :: a -> a -> a, mempty_ :: a } reifiedIns = Sub Dict +instance Reifies s (Def Monoid a) => Semigroup (Lift Monoid a s) where + a <> b = Lift $ mappend_ (reflect a) (lower a) (lower b) + instance Reifies s (Def Monoid a) => Monoid (Lift Monoid a s) where - mappend a b = Lift $ mappend_ (reflect a) (lower a) (lower b) + mappend = (<>) mempty = a where a = Lift $ mempty_ (reflect a) data ClassProxy (p :: * -> Constraint) = ClassProxy diff --git a/examples/FromJSON.hs b/examples/FromJSON.hs --- a/examples/FromJSON.hs +++ b/examples/FromJSON.hs @@ -1,27 +1,30 @@ -- Example of a dynamically generated FromJSON instance. -- --- Can be useful when one needs to use a function with a --- FromJSON constraint, but some detail about the +-- Can be useful when one needs to use a function with a +-- FromJSON constraint, but some detail about the -- conversion from JSON is not known until runtime. +{-# LANGUAGE CPP #-} {-# LANGUAGE Rank2Types #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE UndecidableInstances #-} {-# LANGUAGE ScopedTypeVariables #-} {-# LANGUAGE OverloadedStrings #-} -import Data.Reflection -- from reflection -import Data.Monoid -- from base -import Data.Proxy -- from tagged -import Data.Text -- from text -import Data.Monoid -import Data.Aeson -- from aeson +import Data.Aeson -- from aeson +import qualified Data.Aeson.Key as Key import Data.Aeson.Types (Parser) +import Data.Proxy -- from tagged +import Data.Reflection -- from reflection +#if !(MIN_VERSION_base(4,11,0)) +import Data.Semigroup -- from base +#endif +import Data.Text (Text, pack) -- from text import Control.Applicative -- These imports are only for constructing the example value -import Control.Lens (preview) -- from lens -import Data.Aeson.Lens (_Value,_String) -- form lens-aeson +import Lens.Micro.Aeson (_Value) -- form microlens-aeson +import Lens.Micro.Extras (preview) -- from microlens data Foo = Foo { @@ -31,19 +34,20 @@ fooParser :: Text -> Object -> Parser Foo fooParser prefix o = do - Foo <$> o .: (prefix <> "field1") <*> o .: (prefix <> "field2") + Foo <$> o .: (Key.fromText prefix <> "field1") <*> o .: (Key.fromText prefix <> "field2") -- A wrapper over Foo carrying a phantom type s newtype J a s = J { runJ :: a } - --- If the phantom type s reifies the parsing function, we can --- use reflect to recover the function and implement + +-- If the phantom type s reifies the parsing function, we can +-- use reflect to recover the function and implement -- our FromJSON instance for J. instance Reifies s (Object -> Parser a) => FromJSON (J a s) where parseJSON (Object v) = J <$> reflect (Proxy :: Proxy s) v - + parseJSON _ = empty + -- Convince the compiler that the phantom type in the proxy --- supplied by reify is the same as the phantom type in J. +-- supplied by reify is the same as the phantom type in J. -- -- Otherwise the FromJSON instance for J won't kick in. asProxyJ :: Proxy s -> J a s -> J a s @@ -53,18 +57,18 @@ exampleJSON = maybe Null id (preview _Value str) where str = "{ \"zzfield1\" : 5, \"zzfield2\" : 7 }"::Text - + main :: IO () main = do putStrLn "Enter prefix for the fields: " -- "zz" must be entered for the parse to succeed prefix <- fmap pack getLine - + -- fromJSON uses the dynamically generated FromJSON instance let result = reify (fooParser prefix) $ \proxy -> -- We must eliminate the J newtype before returning -- because, thanks to parametricity, -- the phantom type cannot escape the callback. - runJ . asProxyJ proxy <$> fromJSON exampleJSON - + runJ . asProxyJ proxy <$> fromJSON exampleJSON + putStrLn (show (result :: Result Foo)) diff --git a/examples/Monoid.hs b/examples/Monoid.hs --- a/examples/Monoid.hs +++ b/examples/Monoid.hs @@ -1,11 +1,13 @@ {-# LANGUAGE CPP, Rank2Types, FlexibleContexts, UndecidableInstances #-} module Monoid where +import Data.Proxy -- from tagged import Data.Reflection -- from reflection +#if !(MIN_VERSION_base(4,11,0)) import Data.Semigroup -- from base -import Data.Proxy -- from tagged +#endif --- | Values in our dynamically-constructed 'Monoid' over 'a' +-- | Values in our dynamically-constructed 'Monoid' over @a@ newtype M a s = M { runM :: a } deriving (Eq,Ord) -- | A dictionary describing a 'Monoid' diff --git a/examples/ReaderLike.hs b/examples/ReaderLike.hs --- a/examples/ReaderLike.hs +++ b/examples/ReaderLike.hs @@ -9,7 +9,6 @@ import Data.Proxy import Data.Reflection -import Control.Applicative import System.IO data MyConfig = MyConfig @@ -37,7 +36,7 @@ conf = reflect (Proxy :: Proxy p) run :: forall p. (Reifies p MyConfig) => Proxy p -> IO () -run p = do +run _ = do d1 <- ask "Datum 1:" :: IO (Datum p) d2 <- ask "Datum 2:" :: IO (Datum p) -- look ma, no plumbing @@ -66,4 +65,6 @@ where conf = reflect (Proxy :: Proxy p) abs = undefined signum = undefined + (-) = undefined + negate = undefined fromInteger = Datum diff --git a/examples/reflection-examples.cabal b/examples/reflection-examples.cabal --- a/examples/reflection-examples.cabal +++ b/examples/reflection-examples.cabal @@ -15,16 +15,19 @@ 2004 Oleg Kiselyov and Chung-chieh Shan build-type: Simple cabal-version: >= 1.10 -tested-with: GHC == 7.0.4 - , GHC == 7.2.2 - , GHC == 7.4.2 - , GHC == 7.6.3 - , GHC == 7.8.4 - , GHC == 7.10.3 - , GHC == 8.0.2 +tested-with: GHC == 8.0.2 , GHC == 8.2.2 - , GHC == 8.4.3 - , GHC == 8.6.1 + , 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 == 9.6.6 + , GHC == 9.8.4 + , GHC == 9.10.1 + , GHC == 9.12.1 flag examples default: True @@ -34,24 +37,28 @@ buildable: False exposed-modules: Constraints Monoid - build-depends: base >= 4.8 && < 5, + build-depends: base >= 4.9 && < 5, constraints, - newtype, + newtype-generics >= 0.5.3, reflection, + semigroups, tagged hs-source-dirs: . ghc-options: -Wall + if impl(ghc >= 8.6) + ghc-options: -Wno-star-is-type default-language: Haskell2010 executable reflection-from-json if !flag(examples) buildable: False main-is: FromJSON.hs - build-depends: aeson, - base >= 4.8 && < 5, - lens, - lens-aeson, + build-depends: aeson >= 2 && < 2.3, + base >= 4.9 && < 5, + microlens, + microlens-aeson >= 2.5.1, reflection, + semigroups, tagged, text hs-source-dirs: . @@ -62,10 +69,12 @@ if !flag(examples) buildable: False main-is: ReaderLike.hs - build-depends: base >= 4.8 && < 5, + build-depends: base >= 4.9 && < 5, reflection, tagged hs-source-dirs: . ghc-options: -Wall -threaded -rtsopts + if impl(ghc >= 8.6) + ghc-options: -Wno-star-is-type default-language: Haskell2010 diff --git a/fast/Data/Reflection.hs b/fast/Data/Reflection.hs --- a/fast/Data/Reflection.hs +++ b/fast/Data/Reflection.hs @@ -1,4 +1,5 @@ {-# LANGUAGE CPP #-} +{-# LANGUAGE DataKinds #-} {-# LANGUAGE EmptyDataDecls #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE FlexibleInstances #-} @@ -6,36 +7,23 @@ {-# LANGUAGE KindSignatures #-} {-# LANGUAGE MultiParamTypeClasses #-} {-# LANGUAGE PatternGuards #-} +{-# LANGUAGE PolyKinds #-} {-# LANGUAGE Rank2Types #-} {-# LANGUAGE ScopedTypeVariables #-} -#if __GLASGOW_HASKELL__ >= 706 -{-# LANGUAGE DataKinds #-} -{-# LANGUAGE PolyKinds #-} {-# LANGUAGE TypeOperators #-} -#define USE_TYPE_LITS 1 -#endif #ifdef MIN_VERSION_template_haskell -# if __GLASGOW_HASKELL__ >= 800 -- TH-subset that works with stage1 & unregisterised GHCs {-# LANGUAGE TemplateHaskellQuotes #-} -# else -{-# LANGUAGE TemplateHaskell #-} -# endif #endif {-# LANGUAGE TypeFamilies #-} -{-# LANGUAGE DeriveDataTypeable #-} {-# LANGUAGE UndecidableInstances #-} {-# OPTIONS_GHC -fno-cse #-} {-# OPTIONS_GHC -fno-full-laziness #-} {-# OPTIONS_GHC -fno-float-in #-} -{-# OPTIONS_GHC -fno-warn-orphans #-} -{-# OPTIONS_GHC -fno-warn-unused-binds #-} - -#ifndef MIN_VERSION_base -#define MIN_VERSION_base(x,y,z) 1 -#endif +{-# OPTIONS_GHC -Wno-orphans #-} +{-# OPTIONS_GHC -Wno-unused-binds #-} ---------------------------------------------------------------------------- -- | @@ -77,10 +65,8 @@ -- * Reflection Reifies(..) , reify -#if __GLASGOW_HASKELL__ >= 708 , reifyNat , reifySymbol -#endif , reifyTypeable -- * Given , Given(..) @@ -108,31 +94,26 @@ ) where import Control.Applicative +import Control.Exception #ifdef MIN_VERSION_template_haskell import Control.Monad #endif import Data.Bits - -#if __GLASGOW_HASKELL__ < 710 -import Data.Foldable -#endif - -import Data.Semigroup as Sem +import Data.Coerce (Coercible, coerce) import Data.Proxy - -#if __GLASGOW_HASKELL__ < 710 -import Data.Traversable -#endif - +import Data.Semigroup as Sem import Data.Typeable import Data.Word import Foreign.Ptr import Foreign.StablePtr -#if (__GLASGOW_HASKELL__ >= 707) || (defined(MIN_VERSION_template_haskell) && USE_TYPE_LITS) import GHC.TypeLits +#if MIN_VERSION_base(4,10,0) +import qualified Numeric.Natural as Numeric (Natural) +#else +import Control.Exception (ArithException(..), throw) #endif #ifdef __HUGS__ @@ -149,10 +130,21 @@ import Unsafe.Coerce #endif -#ifdef HLINT -{-# ANN module "HLint: ignore Avoid lambda" #-} +#if MIN_VERSION_base(4,18,0) +import qualified GHC.TypeNats as TN #endif +-- Due to https://gitlab.haskell.org/ghc/ghc/issues/16893, inlining +-- unsafeCoerce too aggressively can cause optimization to become unsound on +-- old versions of GHC. As a workaround, we mark unsafeCoerce-using definitions +-- as NOINLINE where necessary. +-- See https://github.com/ekmett/reflection/issues/47. +#if __GLASGOW_HASKELL__ >= 811 +# define INLINE_UNSAFE_COERCE INLINE +#else +# define INLINE_UNSAFE_COERCE NOINLINE +#endif + ------------------------------------------------------------------------------ -- Reifies ------------------------------------------------------------------------------ @@ -167,28 +159,27 @@ -- | Reify a value at the type level, to be recovered with 'reflect'. reify :: forall a r. a -> (forall (s :: *). Reifies s a => Proxy s -> r) -> r reify a k = unsafeCoerce (Magic k :: Magic a r) (const a) Proxy -{-# INLINE reify #-} +{-# INLINE_UNSAFE_COERCE reify #-} -#if __GLASGOW_HASKELL__ >= 707 instance KnownNat n => Reifies n Integer where reflect = natVal instance KnownSymbol n => Reifies n String where reflect = symbolVal -#endif -#if __GLASGOW_HASKELL__ >= 708 - -------------------------------------------------------------------------------- -- KnownNat -------------------------------------------------------------------------------- -newtype MagicNat r = MagicNat (forall (n :: Nat). KnownNat n => Proxy n -> r) - -- | This upgraded version of 'reify' can be used to generate a 'KnownNat' suitable for use with other APIs. -- +-- Attemping to pass a negative 'Integer' as an argument will result in an +-- 'Underflow' exception. +-- -- /Available only on GHC 7.8+/ -- +-- >>> import GHC.TypeLits +-- -- >>> reifyNat 4 natVal -- 4 -- @@ -196,28 +187,59 @@ -- 4 reifyNat :: forall r. Integer -> (forall (n :: Nat). KnownNat n => Proxy n -> r) -> r -reifyNat n k = unsafeCoerce (MagicNat k :: MagicNat r) n Proxy +#if MIN_VERSION_base(4,18,0) +-- With base-4.18 or later, we can use the API in GHC.TypeNats to define this +-- function directly. +reifyNat n k = TN.withSomeSNat (fromInteger n :: Numeric.Natural) $ + \(sn :: (SNat n)) -> TN.withKnownNat sn $ k (Proxy :: Proxy n) +{-# INLINE reifyNat #-} +#else +-- On older versions of base, we resort to unsafeCoerce. +reifyNat n k = unsafeCoerce (MagicNat k :: MagicNat r) +# if MIN_VERSION_base(4,10,0) + -- Starting with base-4.10, the internal + -- representation of KnownNat changed from Integer + -- to Natural, so make sure to perform the same + -- conversion before unsafeCoercing. + (fromInteger n :: Numeric.Natural) +# else + (if n < 0 then throw Underflow else n) +# endif + Proxy +{-# INLINE_UNSAFE_COERCE reifyNat #-} +newtype MagicNat r = MagicNat (forall (n :: Nat). KnownNat n => Proxy n -> r) +#endif + -------------------------------------------------------------------------------- -- KnownSymbol -------------------------------------------------------------------------------- -newtype MagicSymbol r = MagicSymbol (forall (n :: Symbol). KnownSymbol n => Proxy n -> r) - -- | This upgraded version of 'reify' can be used to generate a 'KnownSymbol' suitable for use with other APIs. -- -- /Available only on GHC 7.8+/ -- +-- >>> import GHC.TypeLits +-- -- >>> reifySymbol "hello" symbolVal -- "hello" -- -- >>> reifySymbol "hello" reflect -- "hello" reifySymbol :: forall r. String -> (forall (n :: Symbol). KnownSymbol n => Proxy n -> r) -> r +#if MIN_VERSION_base(4,18,0) +-- With base-4.18 or later, we can use the API in GHC.TypeNats to define this +-- function directly. +reifySymbol s k = withSomeSSymbol s $ \(ss :: SSymbol s) -> withKnownSymbol ss (k (Proxy :: Proxy s)) +{-# INLINE reifySymbol #-} +#else +-- On older versions of base, we resort to unsafeCoerce. reifySymbol n k = unsafeCoerce (MagicSymbol k :: MagicSymbol r) n Proxy - +{-# INLINE_UNSAFE_COERCE reifySymbol #-} #endif +newtype MagicSymbol r = MagicSymbol (forall (n :: Symbol). KnownSymbol n => Proxy n -> r) + ------------------------------------------------------------------------------ -- Given ------------------------------------------------------------------------------ @@ -238,7 +260,7 @@ -- are in scope, then the behavior is implementation defined. give :: forall a r. a -> (Given a => r) -> r give a k = unsafeCoerce (Gift k :: Gift a r) a -{-# INLINE give #-} +{-# INLINE_UNSAFE_COERCE give #-} -------------------------------------------------------------------------------- -- Explicit Numeric Reflection @@ -288,9 +310,7 @@ -- in the \"Functional Pearl: Implicit Configurations\" paper by Oleg Kiselyov and Chung-Chieh Shan. -- -- @instance Num (Q Exp)@ provided in this package allows writing @$(3)@ --- instead of @$(int 3)@. Sometimes the two will produce the same --- representation (if compiled without the @-DUSE_TYPE_LITS@ preprocessor --- directive). +-- instead of @$(int 3)@. int :: Int -> TypeQ int n = case quotRem n 2 of (0, 0) -> conT ''Z @@ -307,12 +327,6 @@ | n >= 0 = int n | otherwise = error "nat: negative" -#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ < 704 -instance Show (Q a) where - show _ = "Q" -instance Eq (Q a) where - _ == _ = False -#endif instance Num a => Num (Q a) where (+) = liftM2 (+) (*) = liftM2 (*) @@ -329,29 +343,13 @@ -- | This permits the use of $(5) as a type splice. instance Num Type where -#ifdef USE_TYPE_LITS LitT (NumTyLit a) + LitT (NumTyLit b) = LitT (NumTyLit (a+b)) a + b = AppT (AppT (VarT ''(+)) a) b LitT (NumTyLit a) * LitT (NumTyLit b) = LitT (NumTyLit (a*b)) (*) a b = AppT (AppT (VarT ''(GHC.TypeLits.*)) a) b -#if MIN_VERSION_base(4,8,0) a - b = AppT (AppT (VarT ''(-)) a) b -#else - (-) = error "Type.(-): undefined" -#endif fromInteger = LitT . NumTyLit -#else - (+) = error "Type.(+): undefined" - (*) = error "Type.(*): undefined" - (-) = error "Type.(-): undefined" - fromInteger n = case quotRem n 2 of - (0, 0) -> ConT ''Z - (q,-1) -> ConT ''PD `AppT` fromInteger q - (q, 0) -> ConT ''D `AppT` fromInteger q - (q, 1) -> ConT ''SD `AppT` fromInteger q - _ -> error "ghc is bad at math" -#endif abs = error "Type.abs" signum = error "Type.signum" @@ -386,27 +384,12 @@ signum = onProxyType1 signum fromInteger n = ConE 'Proxy `SigE` (ConT ''Proxy `AppT` fromInteger n) -#ifdef USE_TYPE_LITS addProxy :: Proxy a -> Proxy b -> Proxy (a + b) addProxy _ _ = Proxy mulProxy :: Proxy a -> Proxy b -> Proxy (a * b) mulProxy _ _ = Proxy -#if MIN_VERSION_base(4,8,0) subProxy :: Proxy a -> Proxy b -> Proxy (a - b) subProxy _ _ = Proxy -#else -subProxy :: Proxy a -> Proxy b -> Proxy c -subProxy _ _ = error "Exp.(-): undefined" -#endif --- fromInteger = LitT . NumTyLit -#else -addProxy :: Proxy a -> Proxy b -> Proxy c -addProxy _ _ = error "Exp.(+): undefined" -mulProxy :: Proxy a -> Proxy b -> Proxy c -mulProxy _ _ = error "Exp.(*): undefined" -subProxy :: Proxy a -> Proxy b -> Proxy c -subProxy _ _ = error "Exp.(-): undefined" -#endif #endif @@ -448,7 +431,7 @@ GO(T253,253) GO(T254,254) GO(T255,255) #define GO(Tn,n) \ - newtype Tn = Tn Tn deriving Typeable; \ + newtype Tn = Tn Tn; \ instance B Tn where { \ reflectByte _ = n \ }; @@ -466,9 +449,16 @@ _ -> impossible } -newtype W (b0 :: *) (b1 :: *) (b2 :: *) (b3 :: *) = W (W b0 b1 b2 b3) deriving Typeable -newtype Stable (w0 :: *) (w1 :: *) (a :: *) = Stable (Stable w0 w1 a) deriving Typeable +newtype W (b0 :: *) (b1 :: *) (b2 :: *) (b3 :: *) = W (W b0 b1 b2 b3) +newtype StableBox (w0 :: *) (w1 :: *) (a :: *) = StableBox (StableBox w0 w1 a) +newtype Stable (w0 :: *) (w1 :: *) (a :: *) = Stable (Stable w0 w1 a) +data Box a = Box a + +stableBox :: p (Stable w1 w2 a) -> Proxy (StableBox w1 w2 a) +stableBox _ = Proxy +{-# INLINE stableBox #-} + stable :: p b0 -> p b1 -> p b2 -> p b3 -> p b4 -> p b5 -> p b6 -> p b7 -> Proxy (Stable (W b0 b1 b2 b3) (W b4 b5 b6 b7) a) stable _ _ _ _ _ _ _ _ = Proxy @@ -482,35 +472,35 @@ intPtrToStablePtr = castPtrToStablePtr . intPtrToPtr {-# INLINE intPtrToStablePtr #-} -byte0 :: p (Stable (W b0 b1 b2 b3) w1 a) -> Proxy b0 +byte0 :: p (StableBox (W b0 b1 b2 b3) w1 a) -> Proxy b0 byte0 _ = Proxy -byte1 :: p (Stable (W b0 b1 b2 b3) w1 a) -> Proxy b1 +byte1 :: p (StableBox (W b0 b1 b2 b3) w1 a) -> Proxy b1 byte1 _ = Proxy -byte2 :: p (Stable (W b0 b1 b2 b3) w1 a) -> Proxy b2 +byte2 :: p (StableBox (W b0 b1 b2 b3) w1 a) -> Proxy b2 byte2 _ = Proxy -byte3 :: p (Stable (W b0 b1 b2 b3) w1 a) -> Proxy b3 +byte3 :: p (StableBox (W b0 b1 b2 b3) w1 a) -> Proxy b3 byte3 _ = Proxy -byte4 :: p (Stable w0 (W b4 b5 b6 b7) a) -> Proxy b4 +byte4 :: p (StableBox w0 (W b4 b5 b6 b7) a) -> Proxy b4 byte4 _ = Proxy -byte5 :: p (Stable w0 (W b4 b5 b6 b7) a) -> Proxy b5 +byte5 :: p (StableBox w0 (W b4 b5 b6 b7) a) -> Proxy b5 byte5 _ = Proxy -byte6 :: p (Stable w0 (W b4 b5 b6 b7) a) -> Proxy b6 +byte6 :: p (StableBox w0 (W b4 b5 b6 b7) a) -> Proxy b6 byte6 _ = Proxy -byte7 :: p (Stable w0 (W b4 b5 b6 b7) a) -> Proxy b7 +byte7 :: p (StableBox w0 (W b4 b5 b6 b7) a) -> Proxy b7 byte7 _ = Proxy argument :: (p s -> r) -> Proxy s argument _ = Proxy instance (B b0, B b1, B b2, B b3, B b4, B b5, B b6, B b7, w0 ~ W b0 b1 b2 b3, w1 ~ W b4 b5 b6 b7) - => Reifies (Stable w0 w1 a) a where + => Reifies (StableBox w0 w1 a) (Box a) where reflect = r where r = unsafePerformIO $ const <$> deRefStablePtr p <* freeStablePtr p s = argument r @@ -525,22 +515,30 @@ (reflectByte (byte7 s) `shiftL` 56) {-# NOINLINE reflect #-} --- This had to be moved to the top level, due to an apparent bug in --- the ghc inliner introduced in ghc 7.0.x -reflectBefore :: forall (proxy :: * -> *) s b. (Proxy s -> b) -> proxy s -> b -reflectBefore f = const $! f Proxy -{-# NOINLINE reflectBefore #-} +instance Reifies (StableBox w0 w1 a) (Box b) => Reifies (Stable w0 w1 a) b where + reflect p = case reflect (stableBox p) of + Box a -> a +-- Ensure that exactly one dictionary of Reifies (StableBox ...) is created and evaluated per reifyTypeable call. +-- +-- Evaluating the dictionary's thunk frees the allocated StablePtr, and the contents of the StablePtr replace the thunk. +-- Creating two dictionaries would mean a double free upon their evaluation, and leaving a dictionary unevaluated would +-- leak the StablePtr (see https://github.com/ekmett/reflection/issues/54). +-- +-- To separate evaluation of the dictionary and evaluation of the actual argument passed to reifyTypeable, we insert a +-- Box in between. +withStableBox :: Reifies (StableBox w0 w1 a) (Box a) => (Reifies (Stable w0 w1 a) a => Proxy (Stable w0 w1 a) -> r) -> Proxy (Stable w0 w1 a) -> IO r +withStableBox k p = do + _ <- evaluate $ reflect (stableBox p) + evaluate $ k p +{-# NOINLINE withStableBox #-} + -- | Reify a value at the type level in a 'Typeable'-compatible fashion, to be recovered with 'reflect'. -- -- This can be necessary to work around the changes to @Data.Typeable@ in GHC HEAD. reifyTypeable :: Typeable a => a -> (forall (s :: *). (Typeable s, Reifies s a) => Proxy s -> r) -> r -#if MIN_VERSION_base(4,4,0) reifyTypeable a k = unsafeDupablePerformIO $ do -#else -reifyTypeable a k = unsafePerformIO $ do -#endif - p <- newStablePtr a + p <- newStablePtr (Box a) let n = stablePtrToIntPtr p reifyByte (fromIntegral n) (\s0 -> reifyByte (fromIntegral (n `shiftR` 8)) (\s1 -> @@ -550,9 +548,7 @@ reifyByte (fromIntegral (n `shiftR` 40)) (\s5 -> reifyByte (fromIntegral (n `shiftR` 48)) (\s6 -> reifyByte (fromIntegral (n `shiftR` 56)) (\s7 -> - reflectBefore (fmap return k) $ - stable s0 s1 s2 s3 s4 s5 s6 s7)))))))) - + withStableBox k $ stable s0 s1 s2 s3 s4 s5 s6 s7)))))))) data ReifiedMonoid a = ReifiedMonoid { reifiedMappend :: a -> a -> a, reifiedMempty :: a } @@ -577,7 +573,7 @@ reifyMonoid f z m xs = reify (ReifiedMonoid f z) (unreflectedMonoid (m xs)) -- | Fold a value using its 'Foldable' instance using --- explicitly provided 'Monoid' operations. This is like 'fold' +-- explicitly provided 'Monoid' operations. This is like 'Data.Foldable.fold' -- where the 'Monoid' instance can be manually specified. -- -- @ @@ -634,5 +630,5 @@ sequenceBy :: Traversable t => (forall x. x -> f x) -> (forall x y. f (x -> y) -> f x -> f y) -> t (f a) -> f (t a) sequenceBy pur app = reifyApplicative pur app (traverse ReflectedApplicative) -(#.) :: (b -> c) -> (a -> b) -> a -> c -(#.) _ = unsafeCoerce +(#.) :: Coercible c b => (b -> c) -> (a -> b) -> (a -> c) +(#.) _ = coerce (\x -> x :: b) :: forall a b. Coercible b a => a -> b diff --git a/reflection.cabal b/reflection.cabal --- a/reflection.cabal +++ b/reflection.cabal @@ -1,5 +1,5 @@ name: reflection -version: 2.1.4 +version: 2.1.9 license: BSD3 license-file: LICENSE author: Edward A. Kmett, Elliott Hird, Oleg Kiselyov and Chung-chieh Shan @@ -25,20 +25,28 @@ and Chung-chieh Shan (). However, the API has been streamlined to improve performance. . - Austin Seipp's tutorial provides a summary of the + There are a handful of tutorials on how to use this library: + . + * Austin Seipp's tutorial provides a summary of the approach taken by this library, along with more motivating examples. -tested-with: GHC == 7.0.4 - , GHC == 7.2.2 - , GHC == 7.4.2 - , GHC == 7.6.3 - , GHC == 7.8.4 - , GHC == 7.10.3 - , GHC == 8.0.2 + . + * Arnaud Spiwack's tutorial explains how to use this library. +tested-with: GHC == 8.0.2 , GHC == 8.2.2 - , GHC == 8.4.3 - , GHC == 8.6.1 + , 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 == 9.6.6 + , GHC == 9.8.4 + , GHC == 9.10.1 + , GHC == 9.12.1 extra-source-files: + .hlint.yaml examples/reflection-examples.cabal examples/LICENSE examples/*.hs @@ -46,7 +54,6 @@ README.markdown slow/Data/Reflection.hs fast/Data/Reflection.hs - .travis.yml flag slow description: @@ -68,28 +75,18 @@ library ghc-options: -Wall + if impl(ghc >= 8.6) + ghc-options: -Wno-star-is-type - if impl(ghc >= 7.2) - default-extensions: Trustworthy + default-extensions: Trustworthy build-depends: - base >= 2 && < 5 - - if impl(ghc < 7.8) - build-depends: - tagged >= 0.4.4 && < 1 - - if !impl(ghc >= 8.0) - build-depends: - semigroups >= 0.11 && < 0.19 + base >= 4.9 && < 5 default-language: Haskell98 if flag(template-haskell) && impl(ghc) - if !impl(ghc >= 8.0) - other-extensions: TemplateHaskell - -- else - -- other-extensions: TemplateHaskellQuotes -- Hackage doesn't know this extension yet + -- other-extensions: TemplateHaskellQuotes -- Hackage doesn't know this extension yet build-depends: template-haskell if !flag(slow) && (impl(ghc) || impl(hugs)) @@ -105,3 +102,19 @@ CPP exposed-modules: Data.Reflection + +test-suite spec + type: exitcode-stdio-1.0 + hs-source-dirs: tests + main-is: Spec.hs + other-modules: ReifyNatSpec + T47Spec + ghc-options: -Wall + default-language: Haskell98 + build-tool-depends: hspec-discover:hspec-discover >= 1.8 + build-depends: + base >= 4.9 && < 5, + containers >= 0.1 && < 0.8, + hspec >= 2 && < 3, + QuickCheck >= 2 && < 3, + reflection diff --git a/slow/Data/Reflection.hs b/slow/Data/Reflection.hs --- a/slow/Data/Reflection.hs +++ b/slow/Data/Reflection.hs @@ -1,12 +1,15 @@ {-# LANGUAGE CPP #-} +{-# LANGUAGE MonoLocalBinds #-} {-# LANGUAGE MultiParamTypeClasses #-} {-# LANGUAGE FunctionalDependencies #-} +{-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE FlexibleInstances #-} {-# LANGUAGE Rank2Types #-} +{-# LANGUAGE UndecidableInstances #-} {-# OPTIONS_GHC -fno-cse #-} {-# OPTIONS_GHC -fno-full-laziness #-} {-# OPTIONS_GHC -fno-float-in #-} -{-# OPTIONS_GHC -fno-warn-unused-binds #-} +{-# OPTIONS_GHC -Wno-unused-binds #-} ---------------------------------------------------------------------------- -- | -- Module : Data.Reflection @@ -49,6 +52,7 @@ import Foreign.StablePtr import System.IO.Unsafe import Control.Applicative +import Control.Exception import Data.Proxy import Data.Bits import Data.Word @@ -115,9 +119,18 @@ -- reified type. reflect :: proxy s -> a +newtype StableBox b0 b1 b2 b3 b4 b5 b6 b7 a = + StableBox (StableBox b0 b1 b2 b3 b4 b5 b6 b7 a) newtype Stable b0 b1 b2 b3 b4 b5 b6 b7 a = Stable (Stable b0 b1 b2 b3 b4 b5 b6 b7 a) +data Box a = Box a + +stableBox :: p (Stable b0 b1 b2 b3 b4 b5 b6 b7 a) + -> Proxy (StableBox b0 b1 b2 b3 b4 b5 b6 b7 a) +stableBox _ = Proxy +{-# INLINE stableBox #-} + stable :: p b0 -> p b1 -> p b2 -> p b3 -> p b4 -> p b5 -> p b6 -> p b7 -> Proxy (Stable b0 b1 b2 b3 b4 b5 b6 b7 a) stable _ _ _ _ _ _ _ _ = Proxy @@ -131,35 +144,35 @@ intPtrToStablePtr = castPtrToStablePtr . intPtrToPtr {-# INLINE intPtrToStablePtr #-} -byte0 :: p (Stable b0 b1 b2 b3 b4 b5 b6 b7 a) -> Proxy b0 +byte0 :: p (StableBox b0 b1 b2 b3 b4 b5 b6 b7 a) -> Proxy b0 byte0 _ = Proxy -byte1 :: p (Stable b0 b1 b2 b3 b4 b5 b6 b7 a) -> Proxy b1 +byte1 :: p (StableBox b0 b1 b2 b3 b4 b5 b6 b7 a) -> Proxy b1 byte1 _ = Proxy -byte2 :: p (Stable b0 b1 b2 b3 b4 b5 b6 b7 a) -> Proxy b2 +byte2 :: p (StableBox b0 b1 b2 b3 b4 b5 b6 b7 a) -> Proxy b2 byte2 _ = Proxy -byte3 :: p (Stable b0 b1 b2 b3 b4 b5 b6 b7 a) -> Proxy b3 +byte3 :: p (StableBox b0 b1 b2 b3 b4 b5 b6 b7 a) -> Proxy b3 byte3 _ = Proxy -byte4 :: p (Stable b0 b1 b2 b3 b4 b5 b6 b7 a) -> Proxy b4 +byte4 :: p (StableBox b0 b1 b2 b3 b4 b5 b6 b7 a) -> Proxy b4 byte4 _ = Proxy -byte5 :: p (Stable b0 b1 b2 b3 b4 b5 b6 b7 a) -> Proxy b5 +byte5 :: p (StableBox b0 b1 b2 b3 b4 b5 b6 b7 a) -> Proxy b5 byte5 _ = Proxy -byte6 :: p (Stable b0 b1 b2 b3 b4 b5 b6 b7 a) -> Proxy b6 +byte6 :: p (StableBox b0 b1 b2 b3 b4 b5 b6 b7 a) -> Proxy b6 byte6 _ = Proxy -byte7 :: p (Stable b0 b1 b2 b3 b4 b5 b6 b7 a) -> Proxy b7 +byte7 :: p (StableBox b0 b1 b2 b3 b4 b5 b6 b7 a) -> Proxy b7 byte7 _ = Proxy argument :: (p s -> r) -> Proxy s argument _ = Proxy instance (B b0, B b1, B b2, B b3, B b4, B b5, B b6, B b7) - => Reifies (Stable b0 b1 b2 b3 b4 b5 b6 b7 a) a where + => Reifies (StableBox b0 b1 b2 b3 b4 b5 b6 b7 a) (Box a) where reflect = r where r = unsafePerformIO $ const <$> deRefStablePtr p <* freeStablePtr p s = argument r @@ -174,12 +187,34 @@ (reflectByte (byte7 s) `shiftL` 56) {-# NOINLINE reflect #-} --- This had to be moved to the top level, due to an apparent bug in --- the ghc inliner introduced in ghc 7.0.x -reflectBefore :: Reifies s a => (Proxy s -> b) -> proxy s -> b -reflectBefore f = const $! f Proxy -{-# NOINLINE reflectBefore #-} +instance Reifies (StableBox b0 b1 b2 b3 b4 b5 b6 b7 a) (Box b) + => Reifies (Stable b0 b1 b2 b3 b4 b5 b6 b7 a) b where + reflect p = case reflect (stableBox p) of + Box a -> a +-- Ensure that exactly one dictionary of Reifies (StableBox ...) is created and +-- evaluated per reifyTypeable call. +-- +-- Evaluating the dictionary's thunk frees the allocated StablePtr, and the +-- contents of the StablePtr replace the thunk. Creating two dictionaries would +-- mean a double free upon their evaluation, and leaving a dictionary +-- unevaluated would leak the StablePtr +-- (see https://github.com/ekmett/reflection/issues/54). +-- +-- To separate evaluation of the dictionary and evaluation of the actual +-- argument passed to reifyTypeable, we insert a Box in between. +withStableBox + :: Reifies (StableBox b0 b1 b2 b3 b4 b5 b6 b7 a) (Box a) + => (Reifies (Stable b0 b1 b2 b3 b4 b5 b6 b7 a) a + => Proxy (Stable b0 b1 b2 b3 b4 b5 b6 b7 a) + -> r) + -> Proxy (Stable b0 b1 b2 b3 b4 b5 b6 b7 a) + -> IO r +withStableBox k p = do + _ <- evaluate $ reflect (stableBox p) + evaluate $ k p +{-# NOINLINE withStableBox #-} + -- | Reify a value at the type level, to be recovered with 'reflect'. reify :: a -> (forall s. (Reifies s a) => Proxy s -> r) -> r reify a k = unsafeDupablePerformIO $ do @@ -193,5 +228,4 @@ reifyByte (fromIntegral (n `shiftR` 40)) (\s5 -> reifyByte (fromIntegral (n `shiftR` 48)) (\s6 -> reifyByte (fromIntegral (n `shiftR` 56)) (\s7 -> - reflectBefore (fmap return k) $ - stable s0 s1 s2 s3 s4 s5 s6 s7)))))))) + withStableBox k $ stable s0 s1 s2 s3 s4 s5 s6 s7)))))))) diff --git a/tests/ReifyNatSpec.hs b/tests/ReifyNatSpec.hs new file mode 100644 --- /dev/null +++ b/tests/ReifyNatSpec.hs @@ -0,0 +1,50 @@ +{-# LANGUAGE CPP #-} +{-# LANGUAGE ScopedTypeVariables #-} +module ReifyNatSpec where + +import Data.Reflection +import Test.Hspec.QuickCheck +import Test.QuickCheck (NonNegative(..)) + +#if MIN_VERSION_base(4,10,0) +import GHC.TypeNats (natVal) +import Numeric.Natural (Natural) +#endif + +#if __GLASGOW_HASKELL__ != 900 +import Control.Exception (ArithException(..), evaluate) +import Test.QuickCheck (Negative(..)) +#endif + +import Test.Hspec + +main :: IO () +main = hspec spec + +spec :: Spec +spec = + describe "reifyNat" $ do + prop "reify positive Integers and reflect them back" $ + \(NonNegative (i :: Integer)) -> reifyNat i $ \p -> reflect p `shouldBe` i +#if __GLASGOW_HASKELL__ != 900 + -- Inexplicably, this test fails on GHC 9.0 with hspec-2.8.4 or later. + -- Moreover, I suspect that undefined behavior is involved in some way, + -- as the output of hspec will occasionally be swallowed entirely. I have + -- not been able to observe this phenomenon on any other version of GHC, + -- so I will simply disable this test on 9.0. + prop "should throw an Underflow exception on negative inputs" $ + \(Negative (i :: Integer)) -> + reifyNat i (evaluate . reflect) `shouldThrow` (== Underflow) +#endif +#if MIN_VERSION_base(4,10,0) + it "should reflect very large Naturals correctly" $ do -- #41 + let d42, d2_63, d2_64 :: Natural + d42 = 42 + d2_63 = 2^(63 :: Natural) + d2_64 = 2^(64 :: Natural) + reifyNat (toInteger d42) $ \p -> natVal p `shouldBe` d42 + reifyNat (toInteger (d2_63-1)) $ \p -> natVal p `shouldBe` d2_63-1 + reifyNat (toInteger d2_63) $ \p -> natVal p `shouldBe` d2_63 + reifyNat (toInteger (d2_64-1)) $ \p -> natVal p `shouldBe` d2_64-1 + reifyNat (toInteger d2_64) $ \p -> natVal p `shouldBe` d2_64 +#endif diff --git a/tests/Spec.hs b/tests/Spec.hs new file mode 100644 --- /dev/null +++ b/tests/Spec.hs @@ -0,0 +1,1 @@ +{-# OPTIONS_GHC -F -pgmF hspec-discover #-} diff --git a/tests/T47Spec.hs b/tests/T47Spec.hs new file mode 100644 --- /dev/null +++ b/tests/T47Spec.hs @@ -0,0 +1,64 @@ +{-# LANGUAGE FlexibleContexts #-} +{-# LANGUAGE UndecidableInstances #-} +-- | A regression test for issue #47. +module T47Spec where + +import qualified Data.Map as M +import Data.Map (Map) +import Data.Reflection +import Test.Hspec + +main :: IO () +main = hspec spec + +spec :: Spec +spec = + describe "Given" $ do + it "should give Normal properly" $ + give Normal (toJSON (Foo Bar)) `shouldBe` + Object (M.fromList [("Foo",String "Bar")]) + it "should give ViaShow properly" $ + give ViaShow (toJSON (Foo Bar)) `shouldBe` + Object (M.fromList [("Foo",String "SHOWBAR")]) + +---------------------------------------------------------------------------- +-- Types +---------------------------------------------------------------------------- + +data Foo = Foo Bar + +instance Show Foo where + show _ = "SHOWFOO" + +data Bar = Bar | BarBar + +instance Show Bar where + show _ = "SHOWBAR" + +---------------------------------------------------------------------------- +-- ToJSON instances +---------------------------------------------------------------------------- + +instance Given Style => ToJSON Foo where + toJSON (Foo x) = Object $ M.singleton "Foo" (toJSON x) + +instance Given Style => ToJSON Bar where + toJSON x = case given of + Normal -> String $ case x of + Bar -> "Bar" + BarBar -> "BarBar" + ViaShow -> String $ show x + +data Style = Normal | ViaShow + +---------------------------------------------------------------------------- +-- Minimized aeson +---------------------------------------------------------------------------- + +class ToJSON a where + toJSON :: a -> Value + +data Value + = Object !(Map String Value) + | String !String + deriving (Eq, Show)