Added skeleton for reader.

cabal.project

@@ -6,3 +6,8 @@ tests: True
 flags: +embed_data_files
 constraints: skylighting-format-blaze-html >= 0.1.1.1,
              skylighting-format-context >= 0.1.0.2
+
+source-repository-package
+  type: git
+  location: https://github.com/jgm/djoths
+  tag: 511129ccc466acfb948187ff7b0e1ad94c6d1120

pandoc.cabal

@@ -523,7 +523,8 @@ library
                  zlib                  >= 0.5      && < 0.7,
                  xml                   >= 1.3.12   && < 1.4,
                  typst                 >= 0.5      && < 0.5.1,
-                 vector                >= 0.12     && < 0.14
+                 vector                >= 0.12     && < 0.14,
+                 djot                  >= 0.1      && < 0.2
 
   if !os(windows)
     build-depends:  unix >= 2.4 && < 2.9
@@ -580,6 +581,7 @@ library
                    Text.Pandoc.Readers.CSV,
                    Text.Pandoc.Readers.RTF,
                    Text.Pandoc.Readers.Typst,
+                   Text.Pandoc.Readers.Djot,
                    Text.Pandoc.Writers,
                    Text.Pandoc.Writers.Native,
                    Text.Pandoc.Writers.DocBook,

src/Text/Pandoc/Format.hs

@@ -179,6 +179,7 @@ formatFromFilePath x =
     ".csv"      -> defFlavor "csv"
     ".ctx"      -> defFlavor "context"
     ".db"       -> defFlavor "docbook"
+    ".dj"       -> defFlavor "djot"
     ".doc"      -> defFlavor "doc"  -- so we get an "unknown reader" error
     ".docx"     -> defFlavor "docx"
     ".dokuwiki" -> defFlavor "dokuwiki"

src/Text/Pandoc/Readers.hs

@@ -111,6 +111,7 @@ import Text.Pandoc.Readers.EndNote
 import Text.Pandoc.Readers.RIS
 import Text.Pandoc.Readers.RTF
 import Text.Pandoc.Readers.Typst
+import Text.Pandoc.Readers.Djot
 import qualified Text.Pandoc.UTF8 as UTF8
 import Text.Pandoc.Sources (ToSources(..), sourcesToText)
 
@@ -164,7 +165,8 @@ readers = [("native"       , TextReader readNative)
           ,("ris"          , TextReader readRIS)
           ,("rtf"          , TextReader readRTF)
           ,("typst"        , TextReader readTypst)
-           ]
+          ,("djot"         , TextReader readDjot)
+          ]
 
 -- | Retrieve reader, extensions based on format spec (format+extensions).
 getReader :: PandocMonad m => Format.FlavoredFormat -> m (Reader m, Extensions)

src/Text/Pandoc/Readers/Djot.hs

@@ -0,0 +1,51 @@
+{-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedLists #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+
+{- |
+   Module      : Text.Pandoc.Readers.Djot
+   Copyright   : Copyright (C) 2024 John MacFarlane
+   License     : GNU GPL, version 2 or above
+
+   Maintainer  : John MacFarlane <[email protected]>
+   Stability   : alpha
+   Portability : portable
+
+Reads and evaluates a Djot document as a Pandoc AST.
+-}
+module Text.Pandoc.Readers.Djot
+  ( readDjot
+  )
+where
+
+import Text.Pandoc.Class
+import Text.Pandoc.Sources
+import Text.Parsec.Pos (sourceName)  -- TODO export from T.P.Sources?
+import Text.Pandoc.Options
+import Text.Pandoc.Definition
+import qualified Text.Pandoc.UTF8 as UTF8
+import Djot.Options (ParseOptions(..))
+import Djot.Blocks (parseDoc)
+import qualified Djot.AST as D
+import Text.Pandoc.Error (PandocError(..))
+import Control.Monad.Except (throwError)
+import qualified Data.Text as T
+
+-- import Debug.Trace
+
+-- | Read Djot from an input string and return a Pandoc document.
+readDjot :: (PandocMonad m, ToSources a) => ReaderOptions -> a -> m Pandoc
+readDjot _opts inp = do
+  let sources = toSources inp
+  let inputName = case sources of
+        Sources ((pos, _):_) -> sourceName pos
+        _ -> ""
+  case parseDoc ParseOptions{ optSourcePositions = False }
+         (UTF8.fromText $ sourcesToText sources) of
+    Left e -> throwError $ PandocParseError $ T.pack $ show e
+    Right doc -> do
+      pure $ Pandoc mempty mempty -- TODO

stack.yaml

@@ -30,6 +30,8 @@ extra-deps:
 - commonmark-extensions-0.2.5.1
 - commonmark-pandoc-0.2.2
 - typst-0.5
+- git: https://github.com/jgm/djoths
+  commit: 511129ccc466acfb948187ff7b0e1ad94c6d1120
 
 ghc-options:
    "$locals": -fhide-source-paths -Wno-missing-home-modules