[Chore] Use new flake template

Problem: We have introduced a new template for Haskell libraries and
need to update this package according to this template.

Solution: Use new template, bump dependencies, remove unused license,
apply formatting and hlint suggestions.

.github/workflows/check.yml

@@ -0,0 +1,60 @@
+# SPDX-FileCopyrightText: 2023 Serokell <https://serokell.io/>
+#
+# SPDX-License-Identifier: MPL-2.0
+name: Nix flake check
+on: push
+
+jobs:
+  validate:
+    runs-on: [self-hosted, nix]
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: xrefcheck
+        run: nix run github:serokell/xrefcheck
+
+      - name: reuse
+        run: nix build -L .#checks.x86_64-linux.reuse-lint
+        # Run step even if the previous one has failed
+        if: success() || failure()
+
+      - name: hlint
+        run: nix build -L .#checks.x86_64-linux.hlint
+        if: success() || failure()
+
+      - name: stylish-haskell
+        run: nix build -L .#checks.x86_64-linux.stylish-haskell
+        if: success() || failure()
+
+      - name: check-trailing-whitespace
+        run: nix build -L .#checks.x86_64-linux.trailing-whitespace
+        if: success() || failure()
+
+  # Export JSON serialized ghc-versions
+  ghc-versions:
+    runs-on: [self-hosted, nix]
+    outputs:
+      matrix: ${{ steps.set-matrix.outputs.matrix }}
+    steps:
+    - uses: actions/checkout@v3
+
+    - id: set-matrix
+      run: echo "matrix=$(nix eval --json .#ghc-matrix.x86_64-linux)" >> $GITHUB_OUTPUT
+
+  build-and-test:
+    needs: ghc-versions
+    name: ghc${{ matrix.ghc }}
+    runs-on: [self-hosted, nix]
+    strategy:
+      fail-fast: false
+      matrix: ${{fromJson(needs.ghc-versions.outputs.matrix)}}
+
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: build
+        run: nix build -L .#checks.x86_64-linux.ghc${{ matrix.ghc }}:build-all --keep-going
+
+      - name: test
+        run: nix build -L .#checks.x86_64-linux.ghc${{ matrix.ghc }}:test-all --keep-going
+        if: success() || failure()

.stylish-haskell.yaml

@@ -0,0 +1,63 @@
+# SPDX-FileCopyrightText: 2023 Serokell <https://serokell.io>
+#
+# SPDX-License-Identifier: Unlicense
+
+steps:
+  - simple_align:
+      cases: false
+      top_level_patterns: false
+      records: false
+  - imports:
+      align: none
+      list_align: after_alias
+      pad_module_names: false
+      long_list_align: new_line
+      empty_list_align: inherit
+      list_padding: 2
+      separate_lists: true
+      space_surround: false
+      post_qualify: false
+  - trailing_whitespace: {}
+columns: 100
+newline: native
+language_extensions:
+  - BangPatterns
+  - BlockArguments
+  - ConstraintKinds
+  - DataKinds
+  - DefaultSignatures
+  - DeriveAnyClass
+  - DeriveDataTypeable
+  - DeriveGeneric
+  - DerivingStrategies
+  - DerivingVia
+  - EmptyCase
+  - ExistentialQuantification
+  - ExplicitNamespaces
+  - FlexibleContexts
+  - FlexibleInstances
+  - FunctionalDependencies
+  - GADTs
+  - GeneralizedNewtypeDeriving
+  - ImportQualifiedPost
+  - LambdaCase
+  - MultiParamTypeClasses
+  - MultiWayIf
+  - NamedFieldPuns
+  - NumericUnderscores
+  - OverloadedLabels
+  - OverloadedStrings
+  - PatternSynonyms
+  - QuantifiedConstraints
+  - RebindableSyntax
+  - RecordWildCards
+  - RecursiveDo
+  - ScopedTypeVariables
+  - StandaloneDeriving
+  - TemplateHaskell
+  - TemplateHaskellQuotes
+  - TupleSections
+  - TypeApplications
+  - TypeFamilies
+  - TypeOperators
+  - ViewPatterns

LICENSES/LicenseRef-MIT-nmattia.txt

@@ -1,7 +0,0 @@
-Copyright 2019 Nicolas Mattia
-
-Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

LICENSES/Unlicense.txt

@@ -0,0 +1,24 @@
+This is free and unencumbered software released into the public domain.
+
+Anyone is free to copy, modify, publish, use, compile, sell, or
+distribute this software, either in source code form or as a compiled
+binary, for any purpose, commercial or non-commercial, and by any
+means.
+
+In jurisdictions that recognize copyright laws, the author or authors
+of this software dedicate any and all copyright interest in the
+software to the public domain. We make this dedication for the benefit
+of the public at large and to the detriment of our heirs and
+successors. We intend this dedication to be an overt act of
+relinquishment in perpetuity of all present and future rights to this
+software under copyright law.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+
+For more information, please refer to <http://unlicense.org/>

app/utf8-troubleshoot/Main.hs

@@ -2,9 +2,9 @@
 --
 -- SPDX-License-Identifier: MPL-2.0
 
-{-# LANGUAGE CPP #-}
+{-# LANGUAGE CPP              #-}
-{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE LambdaCase       #-}
-{-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE TemplateHaskell  #-}
 {-# LANGUAGE TypeApplications #-}
 
 #include <HsBaseConfig.h>
@@ -57,7 +57,7 @@ showEnvVar name = do
   putStr $ "  * " <> name <> " "
   lookupEnv name >>= \case
     Nothing -> putStrLn "is not set"
-    Just v -> putStrLn $ "= " <> v
+    Just v  -> putStrLn $ "= " <> v
 
 
 showSystem :: IO ()
@@ -107,7 +107,7 @@ showCbits = do
       enc <- c_libcharsetEncoding >>= peekCAString
       putStrLn $ "  * libcharset:locale_charset = " <> enc
 #else
-      putStrLn $ "  * No libcharset."
+      putStrLn "  * No libcharset."
 #endif
 
     showLanginfoh :: IO ()
@@ -116,7 +116,7 @@ showCbits = do
       enc <- c_langinfoEncoding >>= peekCAString
       putStrLn $ "  * langinfo.h:nl_langinfo(CODESET) = " <> enc
 #else
-      putStrLn $ "  * No <langinfo.h>."
+      putStrLn "  * No <langinfo.h>."
 #endif
 
 #if defined(HAVE_LIBCHARSET)
@@ -143,7 +143,7 @@ showLocales = do
     putStrLn "# Locales"
     tryIO callLocalectl >>= \case
       Right out -> do
-        putStrLn $ "  * localectl list-locales:"
+        putStrLn "  * localectl list-locales:"
         showLocaleList (lines out)
       Left _ -> do
         listDir "/usr/lib/locale"

default.nix

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2023 Serokell <https://serokell.io/>
+#
+# SPDX-License-Identifier: MPL-2.0
 (import (
   fetchTarball {
     url = "https://github.com/edolstra/flake-compat/archive/99f1c2157fba4bfe6211a321fd0ee43199025dbf.tar.gz";

flake.lock.license

@@ -0,0 +1,2 @@
+SPDX-FileCopyrightText: 2023 Serokell <https://serokell.io>
+SPDX-License-Identifier: MPL-2.0

flake.nix

@@ -1,38 +1,110 @@
-# SPDX-FileCopyrightText: 2021 Serokell <https://serokell.io/>
+# SPDX-FileCopyrightText: 2023 Serokell <https://serokell.io/>
 #
 # SPDX-License-Identifier: MPL-2.0
-
 {
-  description = "Get your UTF-8 IO right on the first try";
-
   nixConfig = {
     flake-registry = "https://github.com/serokell/flake-registry/raw/master/flake-registry.json";
   };
 
   inputs = {
-    nixpkgs.url = "github:serokell/nixpkgs";
+    flake-utils.url = "github:numtide/flake-utils";
+    flake-compat = {
+      flake = false;
+    };
     haskell-nix = {
       inputs.hackage.follows = "hackage";
       inputs.stackage.follows = "stackage";
     };
-    hackage.flake = false;
+    hackage = {
-    stackage.flake = false;
+      flake = false;
+    };
+    stackage = {
+      flake = false;
+    };
   };
 
-  outputs = { self, nixpkgs, flake-utils, serokell-nix, haskell-nix, hackage, stackage }:
+  outputs = { self, nixpkgs, haskell-nix, hackage, stackage, serokell-nix, flake-compat, flake-utils, ... }:
-    flake-utils.lib.eachSystem [ "x86_64-linux" ] (system:
+    flake-utils.lib.eachDefaultSystem (system:
       let
-        pkgs = nixpkgs.legacyPackages.${system}.extend haskell-nix.overlay;
+        haskellPkgs = haskell-nix.legacyPackages."${system}";
+        pkgs = import nixpkgs {
+          inherit system;
+          overlays = [
+            serokell-nix.overlay
+          ];
+        };
 
-        flake =
+        lib = pkgs.lib;
-          serokell-nix.lib.haskell.makeFlake pkgs.haskell-nix pkgs.haskell-nix.stackProject {
+
-            src = ./.;
+        hs-package-name = "with-utf8";
-            ghcVersions = [ "884" "8107" "901" "921" ];
+
-            modules = [ serokell-nix.lib.haskell.ciBuildOptions ];
+        ghc-versions = [ "884" "8107" "902" "926" "944" ];
-          };
+
-      in flake // {
+        # invoke haskell.nix for each ghc version listed in ghc-versions
-          defaultPackage = flake.packages."with-utf8:lib:with-utf8";
+        pkgs-per-ghc = lib.genAttrs (map (v: "ghc${v}") ghc-versions)
-          defaultApp = flake.apps."with-utf8:exe:utf8-troubleshoot";
+          (ghc: haskellPkgs.haskell-nix.cabalProject {
-        }
+            src = haskellPkgs.haskell-nix.haskellLib.cleanGit {
-    );
+              name = hs-package-name;
+              src = ./.;
+            };
+            compiler-nix-name = ghc;
+
+            # haskell.nix configuration
+            modules = [{
+              packages.${hs-package-name} = {
+                ghcOptions = [
+                  # fail on warnings
+                  "-Werror"
+                  # disable optimisations, we don't need them if we don't package or deploy the executable
+                  "-O0"
+                ];
+              };
+
+            }];
+          });
+
+        # returns the list of all components for a package
+        get-package-components = pkg:
+          # library
+          lib.optional (pkg ? library) pkg.library
+          # haddock
+          ++ lib.optional (pkg ? library) pkg.library.haddock
+          # exes, tests and benchmarks
+          ++ lib.attrValues pkg.exes
+          ++ lib.attrValues pkg.tests
+          ++ lib.attrValues pkg.benchmarks;
+
+        # all components for each specified ghc version
+        build-all = lib.mapAttrs'
+          (ghc: pkg:
+            let components = get-package-components pkg.${hs-package-name}.components;
+            in lib.nameValuePair "${ghc}:build-all"
+              (pkgs.linkFarmFromDrvs "build-all" components)) pkgs-per-ghc;
+
+        # all tests for each specified ghc version
+        test-all = lib.mapAttrs'
+          (ghc: pkg:
+            let tests = lib.filter lib.isDerivation
+              (lib.attrValues pkg.${hs-package-name}.checks);
+            in lib.nameValuePair "${ghc}:test-all"
+              (pkgs.linkFarmFromDrvs "test-all" tests)) pkgs-per-ghc;
+      in {
+        # nixpkgs revision pinned by this flake
+        legacyPackages = pkgs;
+
+        # used to dynamically build a matrix in the GitHub pipeline
+        ghc-matrix = {
+          include = map (ver: { ghc = ver; }) ghc-versions;
+        };
+
+        # derivations that we can run from CI
+        checks = build-all // test-all // {
+
+          trailing-whitespace = pkgs.build.checkTrailingWhitespace ./.;
+          reuse-lint = pkgs.build.reuseLint ./.;
+
+          hlint = pkgs.build.haskell.hlint ./.;
+          stylish-haskell = pkgs.build.haskell.stylish-haskell ./.;
+        };
+      });
 }

lib/Main/Utf8.hs

@@ -62,7 +62,7 @@ withUtf8 act = withStdTerminalHandles $
   bracket
     (liftIO $ getLocaleEncoding <* setLocaleEncoding utf8)
     (liftIO . setLocaleEncoding)
-    (\_ -> act)
+    (const act)
 
 -- | Make standard handles safe to write anything to them.
 --

lib/System/IO/Utf8.hs

@@ -3,7 +3,7 @@
  - SPDX-License-Identifier: MPL-2.0
  -}
 
-{-# LANGUAGE LambdaCase   #-}
+{-# LANGUAGE LambdaCase #-}
 
 -----------------------------------------------------------------------------
 -- |

lib/System/IO/Utf8/Internal.hs

@@ -3,8 +3,7 @@
  - SPDX-License-Identifier: MPL-2.0
  -}
 
-{-# LANGUAGE LambdaCase   #-}
+{-# LANGUAGE LambdaCase #-}
-{-# LANGUAGE ViewPatterns #-}
 
 -- | Internal functions that implement encoding selection logic.
 module System.IO.Utf8.Internal
@@ -83,4 +82,4 @@ chooseBestEnc h hIsTerm (Just enc) = case textEncodingName enc of
     | "//TRANSLIT" `isSuffixOf` name -> pure Keep
     | otherwise -> hIsTerm h >>= \case
         False -> pure $ ChangeFromTo enc (textEncodingName utf8)
-        True -> pure $ ChangeFromTo enc (name ++ "//TRANSLIT")
+        True  -> pure $ ChangeFromTo enc (name ++ "//TRANSLIT")

package.yaml

@@ -37,7 +37,7 @@ ghc-options:
   - -Wredundant-constraints
 
 dependencies:
-  - base >= 4.10 && < 4.17
+  - base >= 4.10 && < 4.19
   - text >= 0.7 && < 2.1
 
 library:

test/Test/Utf8/ReadWrite.hs

@@ -3,8 +3,8 @@
  - SPDX-License-Identifier: MPL-2.0
  -}
 
-{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE LambdaCase          #-}
-{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE OverloadedStrings   #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 
 module Test.Utf8.ReadWrite where
@@ -18,7 +18,7 @@ import Data.Text (Text)
 import GHC.IO.Encoding (utf8)
 import System.IO.Temp (withSystemTempFile)
 
-import Hedgehog (Property, (===), forAll, property)
+import Hedgehog (Property, forAll, property, (===))
 import Test.HUnit (Assertion, assertFailure)
 
 import qualified Data.Text.IO as T
@@ -59,7 +59,7 @@ hprop_readFile = property $ do
 hprop_writeFile :: Property
 hprop_writeFile = property $ do
     str <- forAll $ G.text (R.linear 0 1000) G.unicode
-    liftIO $ withTestFile str (flip Utf8.writeFile str)
+    liftIO $ withTestFile str (`Utf8.writeFile` str)
 
 hprop_openFile :: Property
 hprop_openFile = property $ do
@@ -78,6 +78,5 @@ hprop_withFile = property $ do
     str' <- liftIO $ withTestFile str $ \fp ->
       Utf8.withFile fp IO.ReadMode $ \h -> do
         res <- T.hGetContents h
-        res' <- evaluate . force $ res
+        evaluate . force $ res
-        pure res'
     str === str'

with-utf8.cabal

@@ -1,10 +1,10 @@
 cabal-version: 1.18
 
--- This file has been generated from package.yaml by hpack version 0.34.5.
+-- This file has been generated from package.yaml by hpack version 0.35.2.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 930f59e2f7815f238524f9e35825dd18c98fe04cfb768e3922af929bd6cf8c63
+-- hash: 983535ba7f77c066ffa634f2a4f800eb8988a0e636f0f901fd187e177b64ca6f
 
 name:           with-utf8
 version:        1.0.2.3
@@ -50,7 +50,7 @@ library
       lib
   ghc-options: -Wall -Wcompat -Wincomplete-record-updates -Wincomplete-uni-patterns -Wredundant-constraints
   build-depends:
-      base >=4.10 && <4.17
+      base >=4.10 && <4.19
     , safe-exceptions ==0.1.*
     , text >=0.7 && <2.1
   default-language: Haskell2010
@@ -65,7 +65,7 @@ executable utf8-troubleshoot
   c-sources:
       app/utf8-troubleshoot/cbits/locale.c
   build-depends:
-      base >=4.10 && <4.17
+      base >=4.10 && <4.19
     , directory >=1.2.5.0 && <1.4
     , filepath >=1.0 && <1.5
     , process >=1.0.1.1 && <1.7
@@ -91,7 +91,7 @@ test-suite with-utf8-test
       tasty-discover:tasty-discover
   build-depends:
       HUnit
-    , base >=4.10 && <4.17
+    , base >=4.10 && <4.19
     , deepseq
     , hedgehog
     , safe-exceptions

with-utf8.cabal.license

@@ -0,0 +1,2 @@
+SPDX-FileCopyrightText: 2023 Serokell <https://serokell.io>
+SPDX-License-Identifier: MPL-2.0