API change: move reader functions to Text.Pandoc.Readers

Reader helper functions were defined in the top-level Text.Pandoc
module. These functions are moved to the Readers submodule as to enable
reuse in other submodules.

1 files changed, 146 insertions, 0 deletions

diff --git a/src/Text/Pandoc/Readers.hs b/src/Text/Pandoc/Readers.hs
new file mode 100644
index 000000000..e2d40336c
--- /dev/null
+++ b/src/Text/Pandoc/Readers.hs
@@ -0,0 +1,146 @@
+{-# LANGUAGE FlexibleInstances   #-}
+{-# LANGUAGE GADTs               #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-
+Copyright (C) 2006-2017 John MacFarlane <jgm@berkeley.edu>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+-}
+
+{- |
+   Module      : Text.Pandoc.Readers
+   Copyright   : Copyright (C) 2006-2017 John MacFarlane
+   License     : GNU GPL, version 2 or above
+
+   Maintainer  : John MacFarlane <jgm@berkeley.edu>
+   Stability   : alpha
+   Portability : portable
+
+This helper module exports the readers.
+
+Note:  all of the readers assume that the input text has @'\n'@
+line endings.  So if you get your input text from a web form,
+you should remove @'\r'@ characters using @filter (/='\r')@.
+
+-}
+
+module Text.Pandoc.Readers
+  (
+    -- * Readers: converting /to/ Pandoc format
+    Reader (..)
+  , readers
+  , readDocx
+  , readOdt
+  , readMarkdown
+  , readCommonMark
+  , readMediaWiki
+  , readRST
+  , readOrg
+  , readLaTeX
+  , readHtml
+  , readTextile
+  , readDocBook
+  , readOPML
+  , readHaddock
+  , readNative
+  , readJSON
+  , readTWiki
+  , readTxt2Tags
+  , readEPUB
+  -- * Miscellaneous
+  , getReader
+  , getDefaultExtensions
+  ) where
+
+import Control.Monad.Except (throwError)
+import Data.Aeson
+import Data.List (intercalate)
+import Text.Pandoc.Class
+import Text.Pandoc.Definition
+import Text.Pandoc.Error
+import Text.Pandoc.Extensions
+import Text.Pandoc.Options
+import Text.Pandoc.Readers.CommonMark
+import Text.Pandoc.Readers.DocBook
+import Text.Pandoc.Readers.Docx
+import Text.Pandoc.Readers.EPUB
+import Text.Pandoc.Readers.Haddock
+import Text.Pandoc.Readers.HTML
+import Text.Pandoc.Readers.LaTeX
+import Text.Pandoc.Readers.Markdown
+import Text.Pandoc.Readers.MediaWiki
+import Text.Pandoc.Readers.Native
+import Text.Pandoc.Readers.Odt
+import Text.Pandoc.Readers.OPML
+import Text.Pandoc.Readers.Org
+import Text.Pandoc.Readers.RST
+import Text.Pandoc.Readers.Textile
+import Text.Pandoc.Readers.TWiki
+import Text.Pandoc.Readers.Txt2Tags
+import Text.Pandoc.Shared (mapLeft)
+import Text.Parsec.Error
+import qualified Text.Pandoc.UTF8 as UTF8
+import qualified Data.ByteString.Lazy as BL
+
+data Reader m = StringReader (ReaderOptions -> String -> m Pandoc)
+              | ByteStringReader (ReaderOptions -> BL.ByteString -> m Pandoc)
+
+-- | Association list of formats and readers.
+readers :: PandocMonad m => [(String, Reader m)]
+readers = [ ("native"       , StringReader readNative)
+           ,("json"         , StringReader $ \o s ->
+                                               case readJSON o s of
+                                                 Right doc -> return doc
+                                                 Left _ -> throwError $ PandocParseError "JSON parse error")
+           ,("markdown"     , StringReader readMarkdown)
+           ,("markdown_strict" , StringReader readMarkdown)
+           ,("markdown_phpextra" , StringReader readMarkdown)
+           ,("markdown_github" , StringReader readMarkdown)
+           ,("markdown_mmd",  StringReader readMarkdown)
+           ,("commonmark"   , StringReader readCommonMark)
+           ,("rst"          , StringReader readRST)
+           ,("mediawiki"    , StringReader readMediaWiki)
+           ,("docbook"      , StringReader readDocBook)
+           ,("opml"         , StringReader readOPML)
+           ,("org"          , StringReader readOrg)
+           ,("textile"      , StringReader readTextile) -- TODO : textile+lhs
+           ,("html"         , StringReader readHtml)
+           ,("latex"        , StringReader readLaTeX)
+           ,("haddock"      , StringReader readHaddock)
+           ,("twiki"        , StringReader readTWiki)
+           ,("docx"         , ByteStringReader readDocx)
+           ,("odt"          , ByteStringReader readOdt)
+           ,("t2t"          , StringReader readTxt2Tags)
+           ,("epub"         , ByteStringReader readEPUB)
+           ]
+
+-- | Retrieve reader based on formatSpec (format+extensions).
+getReader :: PandocMonad m => String -> Either String (Reader m)
+getReader s =
+  case parseFormatSpec s of
+       Left e  -> Left $ intercalate "\n" [m | Message m <- errorMessages e]
+       Right (readerName, setExts) ->
+           case lookup readerName readers of
+                   Nothing  -> Left $ "Unknown reader: " ++ readerName
+                   Just  (StringReader r)  -> Right $ StringReader $ \o ->
+                                  r o{ readerExtensions = setExts $
+                                            getDefaultExtensions readerName }
+                   Just (ByteStringReader r) -> Right $ ByteStringReader $ \o ->
+                                  r o{ readerExtensions = setExts $
+                                            getDefaultExtensions readerName }
+
+-- | Read pandoc document from JSON format.
+readJSON :: ReaderOptions -> String -> Either PandocError Pandoc
+readJSON _ = mapLeft PandocParseError . eitherDecode' . UTF8.fromStringLazy