fe2eda9 · typeable/pandoc

git.iko.soy/typeable/pandoc

Docx Reader: Add a compatibility layer for Except.

mtl switched from ErrorT to ExceptT, but we're not sure which mtl we'll be dealing with. This should make errors work with both. The main difference (beside the name of the module and the monad transformer) is that Except doesn't require an instance of an Error Typeclass. So we define that for compatability. When we switch to a later mtl, using Control.Monad.Exception, we can just erase the instance declaration, and all should work fine.

commitfe2eda9d54e64ffa0c6c5c5295c19941040a5f3d authorJesse Rosenthal <jrosenthal@jhu.edu> dateSat 12 Jul 2014, 08:56 (12 years ago) parentd65fd58

3 files changed+31−3

compare with master

unifiedsplit

pandoc.cabal+1 src/Text/Pandoc/Compat/Except.hs+27 src/Text/Pandoc/Readers/Docx/Parse.hs+3−3

pandoc.cabal+1

@@ -340,6 +340,7 @@ Library

340340 Text.Pandoc.Slides,

341341 Text.Pandoc.Highlighting,

342342 Text.Pandoc.Compat.Monoid,

343+ Text.Pandoc.Compat.Except,

343344 Text.Pandoc.Compat.TagSoupEntity,

344345 Paths_pandoc

345346

src/Text/Pandoc/Compat/Except.hsnew file+27

@@ -0,0 +1,27 @@

1+{-# LANGUAGE CPP #-}

2+module Text.Pandoc.Compat.Except ( ExceptT

3+ , Error(..)

4+ , runExceptT

5+ , throwError

6+ , catchError )

7+ where

9+#if MIN_VERSION_mtl(2,2,1)

10+import Control.Monad.Except

11+

12+class Error a where

13+ noMsg :: a

14+ strMsg :: String -> a

15+

16+ noMsg = strMsg ""

17+ strMsg _ = noMsg

18+

19+#else

20+import Control.Monad.Error

21+type ExceptT = ErrorT

22+

23+runExceptT :: ExceptT e m a -> m (Either e a)

24+runExceptT = runErrorT

25+#endif

26+

27+

src/Text/Pandoc/Readers/Docx/Parse.hs+3−3

@@ -69,7 +69,7 @@ import qualified Data.ByteString.Lazy as B

6969import qualified Text.Pandoc.UTF8 as UTF8

7070import Control.Monad.Reader

7171import qualified Data.Map as M

72−import Control.Monad.Error

72+import Text.Pandoc.Compat.Except

7373

7474data ReaderEnv = ReaderEnv { envNotes :: Notes

7575 , envNumbering :: Numbering

@@ -84,10 +84,10 @@ data DocxError = DocxError | WrongElem

8484instance Error DocxError where

8585 noMsg = WrongElem

8686

87−type D = ErrorT DocxError (Reader ReaderEnv)

87+type D = ExceptT DocxError (Reader ReaderEnv)

8888

8989runD :: D a -> ReaderEnv -> Either DocxError a

90−runD dx re = runReader (runErrorT dx ) re

90+runD dx re = runReader (runExceptT dx ) re

9191

9292maybeToD :: Maybe a -> D a

9393maybeToD (Just a) = return a