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Diffstat (limited to 'src/Text/Pandoc/Error.hs')
| -rw-r--r-- | src/Text/Pandoc/Error.hs | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/src/Text/Pandoc/Error.hs b/src/Text/Pandoc/Error.hs new file mode 100644 index 000000000..159f4340c --- /dev/null +++ b/src/Text/Pandoc/Error.hs @@ -0,0 +1,76 @@ +{-# 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 + |
