ghc-plugin-non-empty (empty) → 0.0.0.0
raw patch · 9 files changed
+981/−0 lines, 9 filesdep +basedep +ghcdep +ghc-plugin-non-empty
Dependencies added: base, ghc, ghc-plugin-non-empty, hspec, syb
Files
- CHANGELOG.md +11/−0
- LICENSE +373/−0
- README.md +77/−0
- ghc-plugin-non-empty.cabal +104/−0
- src/GhcPluginNonEmpty.hs +304/−0
- test/Spec.hs +44/−0
- test/Test/Data/Fail.hs +13/−0
- test/Test/Data/Overloaded.hs +24/−0
- test/Test/Data/Plain.hs +31/−0
+ CHANGELOG.md view
@@ -0,0 +1,11 @@+# Changelog++`ghc-plugin-non-empty` uses [PVP Versioning][1].+The changelog is available [on GitHub][2].++## 0.0.0.0 — July 17, 2022 🌇++* Initially created.++[1]: https://pvp.haskell.org+[2]: https://github.com/chshersh/ghc-plugin-non-empty/releases
+ LICENSE view
@@ -0,0 +1,373 @@+Mozilla Public License Version 2.0+==================================++1. Definitions+--------------++1.1. "Contributor"+ means each individual or legal entity that creates, contributes to+ the creation of, or owns Covered Software.++1.2. "Contributor Version"+ means the combination of the Contributions of others (if any) used+ by a Contributor and that particular Contributor's Contribution.++1.3. "Contribution"+ means Covered Software of a particular Contributor.++1.4. "Covered Software"+ means Source Code Form to which the initial Contributor has attached+ the notice in Exhibit A, the Executable Form of such Source Code+ Form, and Modifications of such Source Code Form, in each case+ including portions thereof.++1.5. "Incompatible With Secondary Licenses"+ means++ (a) that the initial Contributor has attached the notice described+ in Exhibit B to the Covered Software; or++ (b) that the Covered Software was made available under the terms of+ version 1.1 or earlier of the License, but not also under the+ terms of a Secondary License.++1.6. "Executable Form"+ means any form of the work other than Source Code Form.++1.7. "Larger Work"+ means a work that combines Covered Software with other material, in+ a separate file or files, that is not Covered Software.++1.8. "License"+ means this document.++1.9. "Licensable"+ means having the right to grant, to the maximum extent possible,+ whether at the time of the initial grant or subsequently, any and+ all of the rights conveyed by this License.++1.10. "Modifications"+ means any of the following:++ (a) any file in Source Code Form that results from an addition to,+ deletion from, or modification of the contents of Covered+ Software; or++ (b) any new file in Source Code Form that contains any Covered+ Software.++1.11. "Patent Claims" of a Contributor+ means any patent claim(s), including without limitation, method,+ process, and apparatus claims, in any patent Licensable by such+ Contributor that would be infringed, but for the grant of the+ License, by the making, using, selling, offering for sale, having+ made, import, or transfer of either its Contributions or its+ Contributor Version.++1.12. "Secondary License"+ means either the GNU General Public License, Version 2.0, the GNU+ Lesser General Public License, Version 2.1, the GNU Affero General+ Public License, Version 3.0, or any later versions of those+ licenses.++1.13. "Source Code Form"+ means the form of the work preferred for making modifications.++1.14. "You" (or "Your")+ means an individual or a legal entity exercising rights under this+ License. For legal entities, "You" includes any entity that+ controls, is controlled by, or is under common control with You. For+ purposes of this definition, "control" means (a) the power, direct+ or indirect, to cause the direction or management of such entity,+ whether by contract or otherwise, or (b) ownership of more than+ fifty percent (50%) of the outstanding shares or beneficial+ ownership of such entity.++2. License Grants and Conditions+--------------------------------++2.1. Grants++Each Contributor hereby grants You a world-wide, royalty-free,+non-exclusive license:++(a) under intellectual property rights (other than patent or trademark)+ Licensable by such Contributor to use, reproduce, make available,+ modify, display, perform, distribute, and otherwise exploit its+ Contributions, either on an unmodified basis, with Modifications, or+ as part of a Larger Work; and++(b) under Patent Claims of such Contributor to make, use, sell, offer+ for sale, have made, import, and otherwise transfer either its+ Contributions or its Contributor Version.++2.2. Effective Date++The licenses granted in Section 2.1 with respect to any Contribution+become effective for each Contribution on the date the Contributor first+distributes such Contribution.++2.3. Limitations on Grant Scope++The licenses granted in this Section 2 are the only rights granted under+this License. No additional rights or licenses will be implied from the+distribution or licensing of Covered Software under this License.+Notwithstanding Section 2.1(b) above, no patent license is granted by a+Contributor:++(a) for any code that a Contributor has removed from Covered Software;+ or++(b) for infringements caused by: (i) Your and any other third party's+ modifications of Covered Software, or (ii) the combination of its+ Contributions with other software (except as part of its Contributor+ Version); or++(c) under Patent Claims infringed by Covered Software in the absence of+ its Contributions.++This License does not grant any rights in the trademarks, service marks,+or logos of any Contributor (except as may be necessary to comply with+the notice requirements in Section 3.4).++2.4. Subsequent Licenses++No Contributor makes additional grants as a result of Your choice to+distribute the Covered Software under a subsequent version of this+License (see Section 10.2) or under the terms of a Secondary License (if+permitted under the terms of Section 3.3).++2.5. Representation++Each Contributor represents that the Contributor believes its+Contributions are its original creation(s) or it has sufficient rights+to grant the rights to its Contributions conveyed by this License.++2.6. Fair Use++This License is not intended to limit any rights You have under+applicable copyright doctrines of fair use, fair dealing, or other+equivalents.++2.7. Conditions++Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted+in Section 2.1.++3. Responsibilities+-------------------++3.1. Distribution of Source Form++All distribution of Covered Software in Source Code Form, including any+Modifications that You create or to which You contribute, must be under+the terms of this License. You must inform recipients that the Source+Code Form of the Covered Software is governed by the terms of this+License, and how they can obtain a copy of this License. You may not+attempt to alter or restrict the recipients' rights in the Source Code+Form.++3.2. Distribution of Executable Form++If You distribute Covered Software in Executable Form then:++(a) such Covered Software must also be made available in Source Code+ Form, as described in Section 3.1, and You must inform recipients of+ the Executable Form how they can obtain a copy of such Source Code+ Form by reasonable means in a timely manner, at a charge no more+ than the cost of distribution to the recipient; and++(b) You may distribute such Executable Form under the terms of this+ License, or sublicense it under different terms, provided that the+ license for the Executable Form does not attempt to limit or alter+ the recipients' rights in the Source Code Form under this License.++3.3. Distribution of a Larger Work++You may create and distribute a Larger Work under terms of Your choice,+provided that You also comply with the requirements of this License for+the Covered Software. If the Larger Work is a combination of Covered+Software with a work governed by one or more Secondary Licenses, and the+Covered Software is not Incompatible With Secondary Licenses, this+License permits You to additionally distribute such Covered Software+under the terms of such Secondary License(s), so that the recipient of+the Larger Work may, at their option, further distribute the Covered+Software under the terms of either this License or such Secondary+License(s).++3.4. Notices++You may not remove or alter the substance of any license notices+(including copyright notices, patent notices, disclaimers of warranty,+or limitations of liability) contained within the Source Code Form of+the Covered Software, except that You may alter any license notices to+the extent required to remedy known factual inaccuracies.++3.5. Application of Additional Terms++You may choose to offer, and to charge a fee for, warranty, support,+indemnity or liability obligations to one or more recipients of Covered+Software. However, You may do so only on Your own behalf, and not on+behalf of any Contributor. You must make it absolutely clear that any+such warranty, support, indemnity, or liability obligation is offered by+You alone, and You hereby agree to indemnify every Contributor for any+liability incurred by such Contributor as a result of warranty, support,+indemnity or liability terms You offer. You may include additional+disclaimers of warranty and limitations of liability specific to any+jurisdiction.++4. Inability to Comply Due to Statute or Regulation+---------------------------------------------------++If it is impossible for You to comply with any of the terms of this+License with respect to some or all of the Covered Software due to+statute, judicial order, or regulation then You must: (a) comply with+the terms of this License to the maximum extent possible; and (b)+describe the limitations and the code they affect. Such description must+be placed in a text file included with all distributions of the Covered+Software under this License. Except to the extent prohibited by statute+or regulation, such description must be sufficiently detailed for a+recipient of ordinary skill to be able to understand it.++5. Termination+--------------++5.1. The rights granted under this License will terminate automatically+if You fail to comply with any of its terms. However, if You become+compliant, then the rights granted under this License from a particular+Contributor are reinstated (a) provisionally, unless and until such+Contributor explicitly and finally terminates Your grants, and (b) on an+ongoing basis, if such Contributor fails to notify You of the+non-compliance by some reasonable means prior to 60 days after You have+come back into compliance. Moreover, Your grants from a particular+Contributor are reinstated on an ongoing basis if such Contributor+notifies You of the non-compliance by some reasonable means, this is the+first time You have received notice of non-compliance with this License+from such Contributor, and You become compliant prior to 30 days after+Your receipt of the notice.++5.2. If You initiate litigation against any entity by asserting a patent+infringement claim (excluding declaratory judgment actions,+counter-claims, and cross-claims) alleging that a Contributor Version+directly or indirectly infringes any patent, then the rights granted to+You by any and all Contributors for the Covered Software under Section+2.1 of this License shall terminate.++5.3. In the event of termination under Sections 5.1 or 5.2 above, all+end user license agreements (excluding distributors and resellers) which+have been validly granted by You or Your distributors under this License+prior to termination shall survive termination.++************************************************************************+* *+* 6. Disclaimer of Warranty *+* ------------------------- *+* *+* Covered Software is provided under this License on an "as is" *+* basis, without warranty of any kind, either expressed, implied, or *+* statutory, including, without limitation, warranties that the *+* Covered Software is free of defects, merchantable, fit for a *+* particular purpose or non-infringing. The entire risk as to the *+* quality and performance of the Covered Software is with You. *+* Should any Covered Software prove defective in any respect, You *+* (not any Contributor) assume the cost of any necessary servicing, *+* repair, or correction. This disclaimer of warranty constitutes an *+* essential part of this License. No use of any Covered Software is *+* authorized under this License except under this disclaimer. *+* *+************************************************************************++************************************************************************+* *+* 7. Limitation of Liability *+* -------------------------- *+* *+* Under no circumstances and under no legal theory, whether tort *+* (including negligence), contract, or otherwise, shall any *+* Contributor, or anyone who distributes Covered Software as *+* permitted above, be liable to You for any direct, indirect, *+* special, incidental, or consequential damages of any character *+* including, without limitation, damages for lost profits, loss of *+* goodwill, work stoppage, computer failure or malfunction, or any *+* and all other commercial damages or losses, even if such party *+* shall have been informed of the possibility of such damages. This *+* limitation of liability shall not apply to liability for death or *+* personal injury resulting from such party's negligence to the *+* extent applicable law prohibits such limitation. Some *+* jurisdictions do not allow the exclusion or limitation of *+* incidental or consequential damages, so this exclusion and *+* limitation may not apply to You. *+* *+************************************************************************++8. Litigation+-------------++Any litigation relating to this License may be brought only in the+courts of a jurisdiction where the defendant maintains its principal+place of business and such litigation shall be governed by laws of that+jurisdiction, without reference to its conflict-of-law provisions.+Nothing in this Section shall prevent a party's ability to bring+cross-claims or counter-claims.++9. Miscellaneous+----------------++This License represents the complete agreement concerning the subject+matter hereof. If any provision of this License is held to be+unenforceable, such provision shall be reformed only to the extent+necessary to make it enforceable. Any law or regulation which provides+that the language of a contract shall be construed against the drafter+shall not be used to construe this License against a Contributor.++10. Versions of the License+---------------------------++10.1. New Versions++Mozilla Foundation is the license steward. Except as provided in Section+10.3, no one other than the license steward has the right to modify or+publish new versions of this License. Each version will be given a+distinguishing version number.++10.2. Effect of New Versions++You may distribute the Covered Software under the terms of the version+of the License under which You originally received the Covered Software,+or under the terms of any subsequent version published by the license+steward.++10.3. Modified Versions++If you create software not governed by this License, and you want to+create a new license for such software, you may create and use a+modified version of this License if you rename the license and remove+any references to the name of the license steward (except to note that+such modified license differs from this License).++10.4. Distributing Source Code Form that is Incompatible With Secondary+Licenses++If You choose to distribute Source Code Form that is Incompatible With+Secondary Licenses under the terms of this version of the License, the+notice described in Exhibit B of this License must be attached.++Exhibit A - Source Code Form License Notice+-------------------------------------------++ This Source Code Form is subject to the terms of the Mozilla Public+ License, v. 2.0. If a copy of the MPL was not distributed with this+ file, You can obtain one at http://mozilla.org/MPL/2.0/.++If it is not possible or desirable to put the notice in a particular+file, then You may include the notice in a location (such as a LICENSE+file in a relevant directory) where a recipient would be likely to look+for such a notice.++You may add additional accurate notices of copyright ownership.++Exhibit B - "Incompatible With Secondary Licenses" Notice+---------------------------------------------------------++ This Source Code Form is "Incompatible With Secondary Licenses", as+ defined by the Mozilla Public License, v. 2.0.
+ README.md view
@@ -0,0 +1,77 @@+# ghc-plugin-non-empty++[](https://github.com/chshersh/ghc-plugin-non-empty/actions)+[](https://hackage.haskell.org/package/ghc-plugin-non-empty)+[](LICENSE)++GHC Compiler Plugin for automatically converting list literals to the+`NonEmpty` type from the `Data.List.NonEmpty` module in `base`.++This plugin checks statically defined list literals and transforms+them into `NonEmpty` lists during compile time. In other words, it+provides compile-time guarantees for non-emptiness checks and allows+the following expression to type-check:++```haskell+portsToListen :: NonEmpty Int+portsToListen = [8000, 8080, 8081]+```++Compare to usage without the plugin:++```haskell+portsToListen :: NonEmpty Int+portsToListen = 8000 :| [8080, 8081]+```++> ℹ️ **DISCLAIMER:** `ghc-plugin-non-empty` is developed and+> maintained in free time by volunteers. The development may continue+> for decades or may stop tomorrow. You can use+> [GitHub Sponsorship](https://github.com/sponsors/chshersh) to support+> the development of this project.++## How to use?++`ghc-plugin-non-empty` is compatible with the following GHC+versions — [supported versions](https://matrix.hackage.haskell.org/#/package/ghc-plugin-non-empty)++In order to start using `ghc-plugin-non-empty` in your project, you'll+need to set it up with these steps:++1. Add the dependency on `ghc-plugin-non-empty` in your project's+ `.cabal` file. For this, you should modify the `build-depends`+ section according to the below section:++ ```haskell+ build-depends:+ , base ^>= LATEST_SUPPORTED_BASE+ , ghc-plugin-non-empty ^>= LATEST_VERSION+ ```++2. To use this package, refer to the below example.++ ```haskell+ {-# OPTIONS_GHC -fplugin=GhcPluginNonEmpty #-}++ module Main (main) where++ import Data.List.NonEmpty (NonEmpty)++ exampleList :: NonEmpty Int+ exampleList = [100, 5, 74]++ main :: IO ()+ main = print exampleList+ ```++## For contributors++Check [CONTRIBUTING.md](https://github.com/chshersh/ghc-plugin-non-empty/blob/main/CONTRIBUTING.md)+for contributing guidelines.++To build the project and run the tests, use `cabal`:++```shell+cabal build all+cabal test --enable-tests --test-show-details=direct+```
+ ghc-plugin-non-empty.cabal view
@@ -0,0 +1,104 @@+cabal-version: 3.0+name: ghc-plugin-non-empty+version: 0.0.0.0+synopsis: GHC Plugin for non-empty lists+description:+ GHC Plugin for compile-time transformation of list literals to @NonEmpty@ lists.++ @+ {-# __OPTIONS_GHC__ -fplugin=GhcPluginNonEmpty #-}++ __import__ Data.List.NonEmpty (NonEmpty)++ portsToListen :: NonEmpty Int+ portsToListen = [8000, 8080, 8081]+ @++ See [README.md](https://github.com/chshersh/ghc-plugin-non-empty#ghc-plugin-non-empty)+ for more details.+homepage: https://github.com/chshersh/ghc-plugin-non-empty+bug-reports: https://github.com/chshersh/ghc-plugin-non-empty/issues+license: MPL-2.0+license-file: LICENSE+author: Dmitrii Kovanikov+maintainer: Dmitrii Kovanikov <kovanikov@gmail.com>+copyright: 2022 Dmitrii Kovanikov+category: GHC, Compiler Plugin+build-type: Simple+extra-doc-files: README.md+ CHANGELOG.md+tested-with: GHC == 9.2.3++source-repository head+ type: git+ location: https://github.com/chshersh/ghc-plugin-non-empty.git++common common-options+ build-depends: base ^>= 4.16++ ghc-options: -Wall+ -Wcompat+ -Widentities+ -Wincomplete-uni-patterns+ -Wincomplete-record-updates+ -Wredundant-constraints+ -Wnoncanonical-monad-instances+ if impl(ghc >= 8.2)+ ghc-options: -fhide-source-paths+ if impl(ghc >= 8.4)+ ghc-options: -Wmissing-export-lists+ -Wpartial-fields+ if impl(ghc >= 8.8)+ ghc-options: -Wmissing-deriving-strategies+ -fwrite-ide-info+ -hiedir=.hie+ if impl(ghc >= 8.10)+ ghc-options: -Wunused-packages+ if impl(ghc >= 9.0)+ ghc-options: -Winvalid-haddock+ if impl(ghc >= 9.2)+ ghc-options: -Wredundant-bang-patterns+ -Woperator-whitespace++ default-language: Haskell2010+ default-extensions: ConstraintKinds+ DeriveGeneric+ DerivingStrategies+ GeneralizedNewtypeDeriving+ InstanceSigs+ KindSignatures+ LambdaCase+ OverloadedStrings+ RecordWildCards+ ScopedTypeVariables+ StandaloneDeriving+ TupleSections+ TypeApplications+ ViewPatterns++library+ import: common-options+ hs-source-dirs: src+ exposed-modules: GhcPluginNonEmpty++ build-depends:+ , ghc ^>= 9.2+ , syb ^>= 0.7++test-suite ghc-plugin-non-empty-test+ import: common-options+ type: exitcode-stdio-1.0+ hs-source-dirs: test++ main-is: Spec.hs+ other-modules: Test.Data.Fail+ Test.Data.Plain+ Test.Data.Overloaded++ build-depends:+ , ghc-plugin-non-empty+ , hspec ^>= 2.10++ ghc-options: -threaded+ -rtsopts+ -with-rtsopts=-N
+ src/GhcPluginNonEmpty.hs view
@@ -0,0 +1,304 @@+{-# LANGUAGE DeriveDataTypeable #-}++{- |+Module : Iris+Copyright : (c) 2022 Dmitrii Kovanikov+SPDX-License-Identifier : MPL-2.0+Maintainer : Dmitrii Kovanikov <kovanikov@gmail.com>+Stability : Stable+Portability : Portable++GHC Plugin for rewriting list literals of non-empty list to 'NonEmpty'+type. Enable the plugin in a module where you want to use it like on+the example below:++@+\{\-\# __OPTIONS_GHC__ -fplugin=GhcPluginNonEmpty \#\-\}++__import__ "Data.List.NonEmpty" ('NonEmpty')++portsToListen :: 'NonEmpty' 'Int'+portsToListen = [8000, 8080, 8081]+@++You can also enable the plugin globally in your entire project from+the @.cabal@ file:++@+library+ ...+ ghc-options: -fplugin=GhcPluginNonEmpty+@++It guarantees that only non-empty lists will be automatically+rewritten. Otherwise, if you use an empty list:++@+portsToListen :: 'NonEmpty' 'Int'+portsToListen = []+@++You'll see ordinary compiler error:++@+src\/Path\/To\/My\/Module:34:17: error:+ • Couldn't match expected type: NonEmpty Int+ with actual type: [a0]+ • In the expression: []+ In an equation for ‘portsToListen’: portsToListen = []+ |+34 | portsToListen = []+ | ^^+@++@since 0.0.0.0+-}++module GhcPluginNonEmpty+ ( plugin++ -- * Internal typeclass for the plugin work+ , GhcPlugnNonEmptyClass (..)+ , cons+ ) where++import GHC.Driver.Plugins (CommandLineOption, Plugin (..), defaultPlugin, purePlugin)+import GHC.Hs.Expr (HsWrap (..), XXExprGhcTc (WrapExpr))+import GHC.Hs.Extension (GhcRn, GhcTc)+import GHC.Iface.Env (lookupOrig)+import GHC.Parser.Annotation (EpAnn (..), SrcSpanAnn' (..))+import GHC.Plugins (Name, mkVarOcc)+import GHC.Tc.Types (TcGblEnv (tcg_binds), TcM)+import GHC.Tc.Types.Evidence (HsWrapper, pprHsWrapper)+import GHC.Tc.Utils.Monad (getTopEnv)+import GHC.Types.SrcLoc (GenLocated (L), SrcSpan (..), UnhelpfulSpanReason (..))+import GHC.Types.TyThing (MonadThings (lookupId))+import GHC.Types.Var (Id)+import GHC.Unit.Finder (FindResult (..), findImportedModule)+import GHC.Unit.Module.ModSummary (ModSummary)+import GHC.Utils.Outputable (defaultSDocContext, renderWithContext, sdocPrintTypecheckerElaboration,+ text)+import Language.Haskell.Syntax.Decls (HsGroup)+import Language.Haskell.Syntax.Expr (HsExpr (..), LHsExpr)+import Language.Haskell.Syntax.Extension (NoExtField (..))++import Control.Monad.IO.Class (MonadIO (..))+import Data.Generics.Aliases (mkM, mkT)+import Data.Generics.Schemes (everywhere, everywhereM)+import Data.List (isInfixOf)+import Data.List.NonEmpty (NonEmpty (..))++import qualified GHC++++{- | Main compiler plugin. Use the following GHC option to enable it:++@+\{\-\# OPTIONS_GHC -fplugin=GhcPluginNonEmpty \#\-\}+@++Implemented in two steps:++1. Rewrites @[3, 1, 2]@ to @'_xxx_ghc_plugin_nonEmpty_fromList' 'cons' [3, 1, 2]@+2. Find applications of '_xxx_ghc_plugin_nonEmpty_fromList' and rewrites them to+ @'cons' 3 [1, 2]@++@since 0.0.0.0+-}+plugin :: Plugin+plugin = defaultPlugin+ { pluginRecompile = purePlugin++ -- 1. Identify list constructors and make them uniform+ , renamedResultAction = wrapLists++ -- 2. Replace list literals with NonEmpty list constructors+ , typeCheckResultAction = replaceNonEmpty+ }++wrapLists+ :: [CommandLineOption]+ -> TcGblEnv+ -> HsGroup GhcRn+ -> TcM (TcGblEnv, HsGroup GhcRn)+wrapLists _options tcGblEnv hsGroup = do+ hscEnv <- getTopEnv++ Found _ ghcPluginNonEmptyModule <- liftIO $ findImportedModule+ hscEnv+ (GHC.mkModuleName "GhcPluginNonEmpty")+ Nothing++ ghcPluginNonEmptyFromListName <- lookupOrig+ ghcPluginNonEmptyModule+ (mkVarOcc "_xxx_ghc_plugin_nonEmpty_fromList")++ nonEmptyCtor <- lookupOrig+ ghcPluginNonEmptyModule+ (mkVarOcc "cons")++ let newHsGroup = everywhere+ (mkT $ rewriteListLiterals ghcPluginNonEmptyFromListName nonEmptyCtor)+ hsGroup++ pure (tcGblEnv, newHsGroup)++rewriteListLiterals+ :: Name+ -> Name+ -> LHsExpr GhcRn+ -> LHsExpr GhcRn+rewriteListLiterals ghcPluginNonEmptyFromListName nonEmptyCtor = \case+ -- rewrite only explicit list literals+ l@(L _ ExplicitList{}) ->+ -- this becomes:+ -- _xxx_ghc_plugin_nonEmpty_fromList cons [3, 1, 2]+ app (app (var ghcPluginNonEmptyFromListName) (var nonEmptyCtor)) l++ -- don't touch other expresions+ expr ->+ expr++mkSpan :: a -> GenLocated (SrcSpanAnn' (EpAnn ann)) a+mkSpan = L $ SrcSpanAnn EpAnnNotUsed $ UnhelpfulSpan UnhelpfulGenerated++app :: LHsExpr GhcRn -> LHsExpr GhcRn -> LHsExpr GhcRn+app l r = mkSpan $ HsApp EpAnnNotUsed l r++var :: Name -> LHsExpr GhcRn+var name = mkSpan $ HsVar NoExtField $ mkSpan name++replaceNonEmpty+ :: [CommandLineOption]+ -> ModSummary+ -> TcGblEnv+ -> TcM TcGblEnv+replaceNonEmpty _options _modSummary tcGblEnv = do+ hscEnv <- getTopEnv++ Found _ ghcPluginNonEmptyModule <- liftIO $ findImportedModule+ hscEnv+ (GHC.mkModuleName "GhcPluginNonEmpty")+ Nothing++ ghcPluginNonEmptyFromListName <- lookupOrig+ ghcPluginNonEmptyModule+ (mkVarOcc "_xxx_ghc_plugin_nonEmpty_fromList")++ ghcPluginNonEmptyFromListId <- lookupId ghcPluginNonEmptyFromListName++ newTcgBinds <- everywhereM+ (mkM $ rewriteToNonEmpty ghcPluginNonEmptyFromListId)+ (tcg_binds tcGblEnv)++ pure tcGblEnv{ tcg_binds = newTcgBinds }++rewriteToNonEmpty+ :: Id+ -> LHsExpr GhcTc+ -> TcM (LHsExpr GhcTc)+rewriteToNonEmpty ghcPluginNonEmptyFromListId = \case+ L+ _+ (HsApp+ _+ (L+ _+ (HsApp+ _+ (L+ _+ (XExpr+ (WrapExpr+ (HsWrap+ varType+ (HsVar _ (L _ varName))+ )+ )+ )+ )+ nonEmptyCtor+ )+ )+ r@(L+ _+ (ExplicitList listType items)+ )+ )+ | varName == ghcPluginNonEmptyFromListId ->+ if isNonEmptyWrapper varType+ -- transform non-empty lists+ then case items of+ -- if the list is empty, we just remove our wrapper and let GHC deal with it+ [] -> pure r++ -- otherwise, we use ctor to create NonEmpty+ x : xs -> pure $ mkSpan $ HsApp EpAnnNotUsed+ (mkSpan $ HsApp EpAnnNotUsed nonEmptyCtor x)+ (mkSpan $ ExplicitList listType xs)++ -- remove the wrapper for ordinary lists+ else pure r++ expr -> pure expr++{- | This function uses a dirty hack to check if the inferred type for+'__xxx_ghc_plugin_nonEmpty_fromList' is for 'NonEmpty'.+-}+isNonEmptyWrapper :: HsWrapper -> Bool+isNonEmptyWrapper hsWrapper = "@NonEmpty" `isInfixOf` strWrapper+ where+ -- HsWrapper pretty-printed as 'String'+ strWrapper :: String+ strWrapper = renderWithContext+ defaultSDocContext { sdocPrintTypecheckerElaboration = True }+ $ pprHsWrapper hsWrapper (\_ -> text "wtf?")++--------------------------+-- List wrapper+--------------------------++{- | ⚠️ __WARNING! Don't use this typeclass!__ ⚠️++This is an internal typeclass for the plugin to work correctly but it+must be imported from this module. Don't use methods of this typeclass+in your code as it may result in incorrect compilation of your code.++@since 0.0.0.0+-}+class GhcPlugnNonEmptyClass listOf where+ -- | @since 0.0.0.0+ _xxx_ghc_plugin_nonEmpty_fromList+ :: (a -> [a] -> NonEmpty a)+ -- ^ Typechecked non-empty constructor+ -> [a]+ -- ^ List literal we're going to rewrite+ -> listOf a+ -- ^ Resulting list++-- | @since 0.0.0.0+instance GhcPlugnNonEmptyClass [] where+ _xxx_ghc_plugin_nonEmpty_fromList :: (a -> [a] -> NonEmpty a) -> [a] -> [a]+ _xxx_ghc_plugin_nonEmpty_fromList _ l = l+ {-# INLINE _xxx_ghc_plugin_nonEmpty_fromList #-}++-- | @since 0.0.0.0+instance GhcPlugnNonEmptyClass NonEmpty where+ _xxx_ghc_plugin_nonEmpty_fromList :: (a -> [a] -> NonEmpty a) -> [a] -> NonEmpty a+ _xxx_ghc_plugin_nonEmpty_fromList = error $ unlines+ [ "Panic! At The 'ghc-plugin-non-empty'"+ , " Remained usage of: _xxx_ghc_plugin_nonEmpty_fromList :: [a] -> NonEmpty a"+ , ""+ , "If you see this error, please open an issue in the plugin with your code example:"+ , ""+ , " * https://github.com/chshersh/ghc-plugin-non-empty/issues/new"+ ]+ {-# NOINLINE _xxx_ghc_plugin_nonEmpty_fromList #-}++{- | Constructor for 'NonEmpty'. Named alias to ':|'.++@since 0.0.0.0+-}+cons :: a -> [a] -> NonEmpty a+cons = (:|)
+ test/Spec.hs view
@@ -0,0 +1,44 @@+{-# LANGUAGE BangPatterns #-}++module Main (main) where++import Control.Exception (ErrorCall, TypeError)+import Data.List.NonEmpty (NonEmpty (..))+import Test.Hspec (describe, hspec, it, shouldBe, shouldThrow)++import Test.Data.Fail as Test+import Test.Data.Overloaded as Test+import Test.Data.Plain as Test+++main :: IO ()+main = hspec $ describe "GhcPluginNonEmpty.plugin" $ do+ describe "Plain" $ do+ it "doesn't change ordinary empty list" $+ Test.emptyList `shouldBe` []+ it "doesn't change ordinary non-empty list" $+ Test.listInt `shouldBe` [3, 1, 2]+ it "correctly converts to non-empty int list" $+ Test.nonEmptyListInt `shouldBe` 5 :| [10, 7]+ it "correctly converts to non-empty bool list" $+ Test.nonEmptyListBool `shouldBe` True :| [False]+ it "correctly converts singleton non-empty int list" $+ Test.nonEmptyListSingleton `shouldBe` 42 :| []+ it "doesn't change explicit non-empty lists" $+ Test.nonEmptyListExplicit `shouldBe` 42 :| [50, 100]++ describe "Fail" $+ it "compiler error on trying to convert empty list to non-empty" $ do+ let action = let !x = Test.emptyNonEmpty in pure x+ action `shouldThrow` \(_ :: TypeError) -> True++ describe "Overloaded" $ do+ it "doesn't change overloaded ordinary empty list" $+ Test.overloadedListEmpty `shouldBe` []+ it "doesn't change overloaded ordinary non-empty list" $+ Test.overloadedListInt `shouldBe` [3, 1, 2]+ it "converts overloaded NonEmpty list" $+ Test.overloadedNonEmptyInt `shouldBe` 15 :| [6, 7]+ it "runtime error on trying to convert empty list to non-empty" $ do+ let action = let !x = Test.overloadedEmptyNonEmpty in pure x+ action `shouldThrow` \(_ :: ErrorCall) -> True
+ test/Test/Data/Fail.hs view
@@ -0,0 +1,13 @@+{-# OPTIONS_GHC -fplugin=GhcPluginNonEmpty #-}+{-# OPTIONS_GHC -fdefer-type-errors #-}+{-# OPTIONS_GHC -Wno-deferred-type-errors #-}++module Test.Data.Fail+ ( emptyNonEmpty+ ) where++import Data.List.NonEmpty (NonEmpty)+++emptyNonEmpty :: NonEmpty Int+emptyNonEmpty = []
+ test/Test/Data/Overloaded.hs view
@@ -0,0 +1,24 @@+{-# OPTIONS_GHC -fplugin=GhcPluginNonEmpty #-}++{-# LANGUAGE OverloadedLists #-}++module Test.Data.Overloaded+ ( overloadedListEmpty+ , overloadedListInt+ , overloadedNonEmptyInt+ , overloadedEmptyNonEmpty+ ) where++import Data.List.NonEmpty (NonEmpty)++overloadedListEmpty :: [Int]+overloadedListEmpty = []++overloadedListInt :: [Int]+overloadedListInt = [3, 1, 2]++overloadedNonEmptyInt :: NonEmpty Int+overloadedNonEmptyInt = [15, 6, 7]++overloadedEmptyNonEmpty :: NonEmpty Int+overloadedEmptyNonEmpty = []
+ test/Test/Data/Plain.hs view
@@ -0,0 +1,31 @@+{-# OPTIONS_GHC -fplugin=GhcPluginNonEmpty #-}++module Test.Data.Plain+ ( emptyList+ , listInt+ , nonEmptyListInt+ , nonEmptyListBool+ , nonEmptyListSingleton+ , nonEmptyListExplicit+ ) where++import Data.List.NonEmpty (NonEmpty (..))+++emptyList :: [Int]+emptyList = []++listInt :: [Int]+listInt = [3, 1, 2]++nonEmptyListInt :: NonEmpty Int+nonEmptyListInt = [5, 10, 7]++nonEmptyListBool :: NonEmpty Bool+nonEmptyListBool = [True, False]++nonEmptyListSingleton :: NonEmpty Int+nonEmptyListSingleton = [42]++nonEmptyListExplicit :: NonEmpty Int+nonEmptyListExplicit = 42 :| [50, 100]