chore: add hls (#10)

Reviewed-on: #10
Co-authored-by: Igor Ranieri <igor@elland.me>
Co-committed-by: Igor Ranieri <igor@elland.me>

.envrc

@@ -0,0 +1 @@
+use nix

.forgejo/workflows/ci.yml

@@ -0,0 +1,2 @@
+runs-on: self-hosted
+

.forgejo/workflows/test.yaml

@@ -0,0 +1,99 @@
+name: Haskell CI
+on:
+  pull_request:
+    branches:
+      - dev
+      - main
+  push:
+    branches:
+      - main
+
+jobs:
+  build:
+    runs-on: docker
+    container:
+      image: elland/haddock2:latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      - name: Check versions
+        run: |
+          ghc --version
+          cabal --version
+          node --version
+      - name: Cache Cabal packages
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.cabal/packages
+            ~/.cabal/store
+            dist-newstyle
+          key: ${{ runner.os }}-haskell-9.10-cabal-${{ hashFiles('**/*.cabal', '**/cabal.project') }}
+          restore-keys: |
+            ${{ runner.os }}-haskell-9.10-cabal-
+      - name: Update Cabal package index
+        run: cabal update
+      - name: Configure project
+        run: cabal configure --enable-tests --enable-benchmarks
+      - name: Build dependencies
+        run: cabal build --only-dependencies --enable-tests --enable-benchmarks
+      - name: Build project
+        run: cabal build --enable-tests --enable-benchmarks
+      - name: Run documentation build
+        run: cabal haddock
+
+  test:
+    runs-on: docker
+    container:
+      image: elland/haddock2:latest
+    needs: build
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      - name: Cache Cabal packages
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.cabal/packages
+            ~/.cabal/store
+            dist-newstyle
+          key: ${{ runner.os }}-haskell-9.10-cabal-${{ hashFiles('**/*.cabal', '**/cabal.project') }}
+          restore-keys: |
+            ${{ runner.os }}-haskell-9.10-cabal-
+      - name: Update Cabal package index
+        run: cabal update
+      - name: Configure project
+        run: cabal configure --enable-tests --enable-benchmarks
+      - name: Build dependencies
+        run: cabal build --only-dependencies --enable-tests --enable-benchmarks
+      - name: Build project
+        run: cabal build --enable-tests --enable-benchmarks
+      - name: Run tests
+        run: cabal test --test-show-details=direct
+
+  fourmolu:
+    runs-on: docker
+    container:
+      image: elland/haddock2:latest
+    needs: build
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      - name: Run fourmolu
+        run: |
+          find src test app -name "*.hs" -exec fourmolu --check-idempotence {} \; 2>/dev/null || true
+          find src test app -name "*.hs" -exec fourmolu --mode check {} \;
+
+  hlint:
+    runs-on: docker
+    container:
+      image: elland/haddock2:latest
+    needs: build
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      - name: Run hlint
+        run: |
+          if [ -d src ]; then hlint src/; fi
+          if [ -d test ]; then hlint test/; fi  
+          if [ -d app ]; then hlint app/; fi

Dockerfile

@@ -0,0 +1,36 @@
+FROM haskell:9.10.2-bullseye AS builder
+
+RUN apt-get update && apt-get install -y curl git && rm -rf /var/lib/apt/lists/*
+
+RUN curl -fsSL https://deb.nodesource.com/setup_22.x | bash - && \
+    apt-get install -y nodejs && \
+    rm -rf /var/lib/apt/lists/*
+
+RUN cabal update && \
+    cabal install --install-method=copy --installdir=/usr/local/bin \
+    fourmolu hlint cabal-gild
+
+WORKDIR /workspace
+
+FROM haskell:9.10.2-bullseye
+
+RUN apt-get update && apt-get install -y \
+    libgmp10 \
+    curl \
+    && rm -rf /var/lib/apt/lists/*
+
+RUN curl -fsSL https://deb.nodesource.com/setup_22.x | bash - && \
+    apt-get install -y nodejs && \
+    rm -rf /var/lib/apt/lists/*
+
+RUN cabal update
+
+COPY --from=builder /usr/local/bin/cabal /usr/local/bin/
+COPY --from=builder /usr/local/bin/fourmolu /usr/local/bin/
+COPY --from=builder /usr/local/bin/hlint /usr/local/bin/
+COPY --from=builder /usr/local/bin/cabal-gild /usr/local/bin/
+
+WORKDIR /workspace
+
+CMD [ "bash" ]
+

Makefile

@@ -1,9 +1,44 @@
 .PHONY: help
-help: ## Show this help.
+help: ## Show this help
 	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | sort | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}'
 
-.PHONY: format
-format:
+.PHONY: build
+build: ## Build the project
+	cabal build
+
+.PHONY: test
+test: ## Run tests
+	cabal test --test-show-details=direct
+
+.PHONY: clean
+clean: ## Clean build artifacts
+	cabal clean
+
+.PHONY: fourmolu
+fourmolu: ## Format Haskell code
 	find . -type f -name "*.hs" ! -path "./dist-newstyle/*" -exec fourmolu -i {} +
+
+.PHONY: fourmolu-check
+fourmolu-check: ## Check if code is formatted
+	find . -type f -name "*.hs" ! -path "./dist-newstyle/*" -exec fourmolu --mode check {} \;
+
+.PHONY: lint
+lint: ## Run hlint
+	hlint src test app
+
+.PHONY: cabal-gild
+cabal-gild: ## Format cabal file
 	cabal-gild --io=haddock2.cabal
 
+.PHONY: format
+format: fourmolu cabal-gild ## Run all formatters
+
+.PHONY: check
+check: fourmolu-check lint ## Run all checks (CI-style)
+
+.PHONY: ci
+ci: build test check ## Run full CI pipeline locally
+
+.PHONY: docs
+docs: ## Generate documentation
+	cabal haddock --haddock-hyperlink-source

npins/default.nix

@@ -0,0 +1,146 @@
+/*
+  This file is provided under the MIT licence:
+
+  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.
+*/
+# Generated by npins. Do not modify; will be overwritten regularly
+let
+  data = builtins.fromJSON (builtins.readFile ./sources.json);
+  version = data.version;
+
+  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/lists.nix#L295
+  range =
+    first: last: if first > last then [ ] else builtins.genList (n: first + n) (last - first + 1);
+
+  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L257
+  stringToCharacters = s: map (p: builtins.substring p 1 s) (range 0 (builtins.stringLength s - 1));
+
+  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L269
+  stringAsChars = f: s: concatStrings (map f (stringToCharacters s));
+  concatMapStrings = f: list: concatStrings (map f list);
+  concatStrings = builtins.concatStringsSep "";
+
+  # If the environment variable NPINS_OVERRIDE_${name} is set, then use
+  # the path directly as opposed to the fetched source.
+  # (Taken from Niv for compatibility)
+  mayOverride =
+    name: path:
+    let
+      envVarName = "NPINS_OVERRIDE_${saneName}";
+      saneName = stringAsChars (c: if (builtins.match "[a-zA-Z0-9]" c) == null then "_" else c) name;
+      ersatz = builtins.getEnv envVarName;
+    in
+    if ersatz == "" then
+      path
+    else
+      # this turns the string into an actual Nix path (for both absolute and
+      # relative paths)
+      builtins.trace "Overriding path of \"${name}\" with \"${ersatz}\" due to set \"${envVarName}\"" (
+        if builtins.substring 0 1 ersatz == "/" then
+          /. + ersatz
+        else
+          /. + builtins.getEnv "PWD" + "/${ersatz}"
+      );
+
+  mkSource =
+    name: spec:
+    assert spec ? type;
+    let
+      path =
+        if spec.type == "Git" then
+          mkGitSource spec
+        else if spec.type == "GitRelease" then
+          mkGitSource spec
+        else if spec.type == "PyPi" then
+          mkPyPiSource spec
+        else if spec.type == "Channel" then
+          mkChannelSource spec
+        else if spec.type == "Tarball" then
+          mkTarballSource spec
+        else
+          builtins.throw "Unknown source type ${spec.type}";
+    in
+    spec // { outPath = mayOverride name path; };
+
+  mkGitSource =
+    {
+      repository,
+      revision,
+      url ? null,
+      submodules,
+      hash,
+      branch ? null,
+      ...
+    }:
+    assert repository ? type;
+    # At the moment, either it is a plain git repository (which has an url), or it is a GitHub/GitLab repository
+    # In the latter case, there we will always be an url to the tarball
+    if url != null && !submodules then
+      builtins.fetchTarball {
+        inherit url;
+        sha256 = hash; # FIXME: check nix version & use SRI hashes
+      }
+    else
+      let
+        url =
+          if repository.type == "Git" then
+            repository.url
+          else if repository.type == "GitHub" then
+            "https://github.com/${repository.owner}/${repository.repo}.git"
+          else if repository.type == "GitLab" then
+            "${repository.server}/${repository.repo_path}.git"
+          else
+            throw "Unrecognized repository type ${repository.type}";
+        urlToName =
+          url: rev:
+          let
+            matched = builtins.match "^.*/([^/]*)(\\.git)?$" url;
+
+            short = builtins.substring 0 7 rev;
+
+            appendShort = if (builtins.match "[a-f0-9]*" rev) != null then "-${short}" else "";
+          in
+          "${if matched == null then "source" else builtins.head matched}${appendShort}";
+        name = urlToName url revision;
+      in
+      builtins.fetchGit {
+        rev = revision;
+        inherit name;
+        # hash = hash;
+        inherit url submodules;
+      };
+
+  mkPyPiSource =
+    { url, hash, ... }:
+    builtins.fetchurl {
+      inherit url;
+      sha256 = hash;
+    };
+
+  mkChannelSource =
+    { url, hash, ... }:
+    builtins.fetchTarball {
+      inherit url;
+      sha256 = hash;
+    };
+
+  mkTarballSource =
+    {
+      url,
+      locked_url ? url,
+      hash,
+      ...
+    }:
+    builtins.fetchTarball {
+      url = locked_url;
+      sha256 = hash;
+    };
+in
+if version == 5 then
+  builtins.mapAttrs mkSource data.pins
+else
+  throw "Unsupported format version ${toString version} in sources.json. Try running `npins upgrade`"

npins/sources.json

@@ -0,0 +1,11 @@
+{
+  "pins": {
+    "nixpkgs": {
+      "type": "Channel",
+      "name": "nixpkgs-unstable",
+      "url": "https://releases.nixos.org/nixpkgs/nixpkgs-25.11pre868532.647e5c14cbd5/nixexprs.tar.xz",
+      "hash": "0i6mgl7pm7y4ydrrll7szmv8hhxb3cyny8x1g1a8sp3g5wl3yd9g"
+    }
+  },
+  "version": 5
+}

shell.nix

@@ -0,0 +1,25 @@
+let
+  sources = import ./npins;
+in
+{
+  pkgs ? import sources.nixpkgs { },
+}:
+
+pkgs.mkShell rec {
+  name = "haddock2";
+
+  packages =
+    with pkgs;
+    [
+      haskell.packages.ghc912.ghc
+      haskell.packages.ghc912.haskell-language-server
+      zlib
+    ]
+    ++ map haskell.lib.justStaticExecutables [
+      haskellPackages.cabal-gild
+      haskellPackages.fourmolu
+      cabal-install
+    ];
+
+  env.LD_LIBRARY_PATH = pkgs.lib.makeLibraryPath packages;
+}

src/Lexer.hs

@@ -8,10 +8,11 @@ module Lexer (
 where
 
 import Control.Monad (mfilter, void)
+import Data.Char (ord, toLower)
 import Data.Functor (($>))
 import Data.Text (Text, intercalate)
 import Data.Text qualified as Text
-import GHC.Unicode (isAlphaNum, isControl, isPrint, isSpace, isUpper)
+import GHC.Unicode (isAlphaNum, isControl, isDigit, isPrint, isSpace, isUpper)
 import ParserMonad (Parser, initialParserState)
 import Text.Parsec
 import Text.Parsec qualified as Parsec
@@ -69,7 +70,7 @@ located :: Parser a -> Parser (SourcePos, a)
 located p = (,) <$> getPosition <*> p
 
 tokenise :: [Parser a] -> Parser [(SourcePos, a)]
-tokenise = sequence . map located
+tokenise = mapM located
 
 lexer :: String -> Either ParseError [LocatedToken]
 lexer = Parsec.runParser lexText initialParserState "input" . Text.pack
@@ -94,6 +95,7 @@ lexText = go
                   , labeledLink
                   , module_
                   , anchor
+                  , numericEntity
                   , textElement
                   , quotes
                   , birdTrack
@@ -146,7 +148,7 @@ delimitedNoTrailing openP closeP openTok = asList <$> delimitedAsTuple (openTok
   asList (a, tok, _) = [a, tok]
 
 delimitedSymmetric :: Parser a -> Token -> Token -> Parser [LocatedToken]
-delimitedSymmetric s t1 t2 = delimited s s t1 t2
+delimitedSymmetric s = delimited s s
 
 eol :: Parser ()
 eol = void "\n" <|> void "\r\n" <|> Parsec.eof
@@ -255,6 +257,30 @@ bold = delimitedSymmetric "__" BoldOpen BoldClose
 monospace :: Lexer
 monospace = delimitedSymmetric "@" MonospaceOpen MonospaceClose
 
+decimal :: Parser Int
+decimal = read . Text.unpack <$> takeWhile1_ isDigit
+
+hexadecimal :: Parser Int
+hexadecimal = "x" *> (convert 0 . fmap (normalise . toLower) <$> many1 hexDigit)
+ where
+  normalise :: Char -> Int
+  normalise c
+    | ord '0' <= n && n <= ord '9' = n - ord '0'
+    | ord 'A' <= n && n <= ord 'F' = n - ord 'A' + 10
+    | ord 'a' <= n && n <= ord 'f' = n - ord 'a' + 10
+    | otherwise = error "unexpected: invalid hex number"
+   where
+    n = ord c
+
+  convert :: Int -> [Int] -> Int
+  convert acc [] = acc
+  convert acc (x : xs) = convert (acc * 16 + x) xs
+
+numericEntity :: Lexer
+numericEntity = do
+  x <- located $ between "&#" ";" (NumericEntity <$> (hexadecimal <|> decimal))
+  pure [x]
+
 other :: Lexer
 other = do
   pos <- getPosition

src/Parser/Util.hs

@@ -13,7 +13,9 @@ import Text.Parsec.Pos (updatePosChar)
 Return everything consumed except for the end pattern itself.
 -}
 takeUntil :: Text -> Parser Text
-takeUntil end_ = Text.dropEnd (Text.length end_) <$> requireEnd (scan p (False, end)) >>= gotSome
+takeUntil end_ =
+  requireEnd (scan p (False, end))
+    >>= gotSome . Text.dropEnd (Text.length end_)
  where
   end = Text.unpack end_
 

src/Types.hs

@@ -9,6 +9,8 @@ module Types (
 )
 where
 
+import Data.Foldable (fold)
+
 newtype Document = Document
   { meta :: Meta
   }
@@ -28,6 +30,7 @@ data Since = Since
 
 -- Could have a better type?
 type Version = [Int]
+
 type Package = String
 
 data DocMarkup mod id
@@ -136,7 +139,7 @@ instance Semigroup (DocMarkup mod id) where
 
 instance Monoid (DocMarkup mod id) where
   mempty = DocEmpty
-  mconcat = foldr (<>) mempty
+  mconcat = fold
 
 data ModuleLink id = ModuleLink
   { name :: String

test/Spec.hs

@@ -1,16 +1,15 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# OPTIONS_GHC -Wno-orphans #-}
 
-import Test.Hspec
-
+import Data.String (IsString (..))
+import Data.Text (Text)
+import GHC.Stack
 import Identifier (Identifier)
 import Lexer
 import Parser
 import Types
 
-import Data.String (IsString (..))
-import Data.Text (Text)
-import GHC.Stack
+import Test.Hspec
 import Text.Parsec.Pos
 
 main :: IO ()
@@ -30,13 +29,14 @@ main = hspec $ do
       it "bird tracks" birdTracks
       it "module names" modules
       it "quotes" quotes
+      it "numeric entity" numericEntity
       it "ignores nesting" ignoreNesting
 
   describe "Parser" do
     it "Bold" do
-      "__bold__" `shouldParseTo` (DocBold (DocString "bold"))
+      "__bold__" `shouldParseTo` DocBold (DocString "bold")
     it "Emphasis" do
-      "/emphasis/" `shouldParseTo` (DocEmphasis (DocString "emphasis"))
+      "/emphasis/" `shouldParseTo` DocEmphasis (DocString "emphasis")
 
 ------------
 -- Tests
@@ -57,6 +57,7 @@ modules = do
     `shouldLexTo` [ (1, 2, Module "OtherModule.Name")
                   , (1, 18, Anchor "myAnchor")
                   ]
+
 link :: Expectation
 link =
   "[link to](http://some.website)"
@@ -152,6 +153,18 @@ space = do
                   , (1, 2, Newline)
                   ]
 
+numericEntity :: Expectation
+numericEntity = do
+  "A λ"
+    `shouldLexTo` [ (1, 1, NumericEntity 65)
+                  , (1, 6, Space)
+                  , (1, 7, NumericEntity 955) -- lambda
+                  ]
+  -- Hex
+  "e"
+    `shouldLexTo` [ (1, 1, NumericEntity 101)
+                  ]
+
 monospace :: Expectation
 monospace =
   "@mono@"