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Diffstat (limited to 'src/Text/Pandoc/Readers/Custom.hs')
-rw-r--r-- | src/Text/Pandoc/Readers/Custom.hs | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/src/Text/Pandoc/Readers/Custom.hs b/src/Text/Pandoc/Readers/Custom.hs new file mode 100644 index 000000000..83d82a9cc --- /dev/null +++ b/src/Text/Pandoc/Readers/Custom.hs @@ -0,0 +1,55 @@ +{-# LANGUAGE FlexibleContexts #-} +{-# LANGUAGE FlexibleInstances #-} +{-# LANGUAGE OverloadedStrings #-} +{-# LANGUAGE ScopedTypeVariables #-} +{-# LANGUAGE TypeApplications #-} +{- | + Module : Text.Pandoc.Readers.Custom + Copyright : Copyright (C) 2021 John MacFarlane + License : GNU GPL, version 2 or above + + Maintainer : John MacFarlane <jgm@berkeley.edu> + Stability : alpha + Portability : portable + +Supports custom parsers written in Lua which produce a Pandoc AST. +-} +module Text.Pandoc.Readers.Custom ( readCustom ) where +import Control.Exception +import Control.Monad (when) +import Data.Text (Text) +import HsLua as Lua hiding (Operation (Div), render) +import HsLua.Class.Peekable (PeekError) +import Control.Monad.IO.Class (MonadIO) +import Text.Pandoc.Definition +import Text.Pandoc.Lua (Global (..), runLua, setGlobals) +import Text.Pandoc.Lua.Util (dofileWithTraceback) +import Text.Pandoc.Options +import Text.Pandoc.Class (PandocMonad) +import Text.Pandoc.Sources (ToSources(..), sourcesToText) + +-- | Convert custom markup to Pandoc. +readCustom :: (PandocMonad m, MonadIO m, ToSources s) + => FilePath -> ReaderOptions -> s -> m Pandoc +readCustom luaFile opts sources = do + let input = sourcesToText $ toSources sources + let globals = [ PANDOC_SCRIPT_FILE luaFile + , PANDOC_READER_OPTIONS opts + ] + res <- runLua $ do + setGlobals globals + stat <- dofileWithTraceback luaFile + -- check for error in lua script (later we'll change the return type + -- to handle this more gracefully): + when (stat /= Lua.OK) + Lua.throwErrorAsException + parseCustom input + case res of + Left msg -> throw msg + Right doc -> return doc + +parseCustom :: forall e. PeekError e + => Text + -> LuaE e Pandoc +parseCustom = invoke @e "Reader" + |