{-

Copyright (C) 2011-2017 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.Native

   Copyright   : Copyright (C) 2011-2017 John MacFarlane

   License     : GNU GPL, version 2 or above

   Maintainer  : John MacFarlane <jgm@berkeley.edu>

   Stability   : alpha

   Portability : portable

Conversion of a string representation of a pandoc type (@Pandoc@,

@[Block]@, @Block@, @[Inline]@, or @Inline@) to a @Pandoc@ document.

-}

module Text.Pandoc.Readers.Native ( readNative ) where

import Text.Pandoc.Definition

import Text.Pandoc.Options (ReaderOptions)

import Text.Pandoc.Shared (safeRead)

import Control.Monad.Except (throwError)

import Data.Text (Text, unpack)

import Text.Pandoc.Class

import Text.Pandoc.Error

-- | Read native formatted text and return a Pandoc document.

-- The input may be a full pandoc document, a block list, a block,

-- an inline list, or an inline.  Thus, for example,

--

-- > Str "hi"

--

-- will be treated as if it were

--

-- > Pandoc nullMeta [Plain [Str "hi"]]

--

readNative :: PandocMonad m

           => ReaderOptions

           -> Text       -- ^ String to parse (assuming @'\n'@ line endings)

           -> m Pandoc

readNative _ s =

  case maybe (Pandoc nullMeta <$> readBlocks s) Right (safeRead (unpack s)) of

    Right doc -> return doc

    Left _    -> throwError $ PandocParseError "couldn't read native"

readBlocks :: Text -> Either PandocError [Block]

readBlocks s = maybe ((:[]) <$> readBlock s) Right (safeRead (unpack s))

readBlock :: Text -> Either PandocError Block

readBlock s = maybe (Plain <$> readInlines s) Right (safeRead (unpack s))

readInlines :: Text -> Either PandocError [Inline]

readInlines s = maybe ((:[]) <$> readInline s) Right (safeRead (unpack s))

readInline :: Text -> Either PandocError Inline

readInline s = maybe (Left . PandocParseError $ "Could not read: " ++ unpack s) Right (safeRead (unpack s))