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+{-# LANGUAGE DeriveDataTypeable, DeriveGeneric #-}
+{-
+Copyright (C) 2006-2016 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.Error
+ Copyright : Copyright (C) 2006-2016 John MacFarlane
+ License : GNU GPL, version 2 or above
+
+ Maintainer : John MacFarlane <jgm@berkeley.edu>
+ Stability : alpha
+ Portability : portable
+
+This module provides a standard way to deal with possible errors encounted
+during parsing.
+
+-}
+module Text.Pandoc.Error (
+ PandocError(..),
+ handleError) where
+
+import Text.Parsec.Error
+import Text.Parsec.Pos hiding (Line)
+import Data.Generics (Typeable)
+import GHC.Generics (Generic)
+import Control.Exception (Exception)
+import Text.Pandoc.Shared (err)
+
+type Input = String
+
+data PandocError = PandocIOError String IOError
+ | PandocShouldNeverHappenError String
+ | PandocSomeError String
+ | PandocParseError String
+ | PandocParsecError Input ParseError
+ | PandocMakePDFError String
+ deriving (Show, Typeable, Generic)
+
+instance Exception PandocError
+
+-- | Handle PandocError by exiting with an error message.
+handleError :: Either PandocError a -> IO a
+handleError (Right r) = return r
+handleError (Left e) =
+ case e of
+ PandocIOError _ err' -> ioError err'
+ PandocShouldNeverHappenError s -> err 62 s
+ PandocSomeError s -> err 63 s
+ PandocParseError s -> err 64 s
+ PandocParsecError input err' ->
+ let errPos = errorPos err'
+ errLine = sourceLine errPos
+ errColumn = sourceColumn errPos
+ ls = lines input ++ [""]
+ errorInFile = if length ls > errLine - 1
+ then concat ["\n", (ls !! (errLine - 1))
+ ,"\n", replicate (errColumn - 1) ' '
+ ,"^"]
+ else ""
+ in err 65 $ "\nError at " ++ show err' ++ errorInFile
+ PandocMakePDFError s -> err 65 s
+