T.P.Error: Remove PandocParsecError constructor from PandocError.

T.P.Parsing now exports `fromParsecError`, which can be used
to turn a parsec ParseError into a regular PandocParseError
(the appearance to the user should be unchanged in every case).

[API change]

Closes #8382.

MANUAL.txt

@@ -1539,7 +1539,6 @@ Nonzero exit codes have the following meanings:
    62 PandocShouldNeverHappenError
    63 PandocSomeError
    64 PandocParseError
-   65 PandocParsecError
    66 PandocMakePDFError
    67 PandocSyntaxMapError
    83 PandocFilterError

src/Text/Pandoc/Error.hs

@@ -23,18 +23,13 @@ import Control.Exception (Exception, displayException)
 import Data.Typeable (Typeable)
 import Data.Word (Word8)
 import Data.Text (Text)
-import Data.List (sortOn)
 import qualified Data.Text as T
-import Data.Ord (Down(..))
 import GHC.Generics (Generic)
 import Network.HTTP.Client (HttpException)
 import System.Exit (ExitCode (..), exitWith)
 import System.IO (stderr)
 import qualified Text.Pandoc.UTF8 as UTF8
-import Text.Pandoc.Sources (Sources(..))
 import Text.Printf (printf)
-import Text.Parsec.Error
-import Text.Parsec.Pos hiding (Line)
 import Text.Pandoc.Shared (tshow)
 import Citeproc (CiteprocError, prettyCiteprocError)
 
@@ -43,7 +38,6 @@ data PandocError = PandocIOError Text IOError
                  | PandocShouldNeverHappenError Text
                  | PandocSomeError Text
                  | PandocParseError Text
-                 | PandocParsecError Sources ParseError
                  | PandocMakePDFError Text
                  | PandocOptionError Text
                  | PandocSyntaxMapError Text
@@ -85,28 +79,6 @@ renderError e =
       "Please report this to pandoc's developers: " <> s
     PandocSomeError s -> s
     PandocParseError s -> s
-    PandocParsecError (Sources inputs) err' ->
-        let errPos = errorPos err'
-            errLine = sourceLine errPos
-            errColumn = sourceColumn errPos
-            errFile = sourceName errPos
-            errorInFile =
-              case sortOn (Down . sourceLine . fst)
-                      [ (pos,t)
-                        | (pos,t) <- inputs
-                        , sourceName pos == errFile
-                        , sourceLine pos <= errLine
-                      ] of
-                []  -> ""
-                ((pos,txt):_) ->
-                  let ls = T.lines txt <> [""]
-                      ln = (errLine - sourceLine pos) + 1
-                   in if length ls > ln && ln >= 1
-                         then T.concat ["\n", ls !! (ln - 1)
-                                       ,"\n", T.replicate (errColumn - 1) " "
-                                       ,"^"]
-                         else ""
-        in  "Error at " <> tshow  err' <> errorInFile
     PandocMakePDFError s -> s
     PandocOptionError s -> s
     PandocSyntaxMapError s -> s
@@ -198,7 +170,6 @@ handleError (Left e) =
       PandocShouldNeverHappenError{} -> 62
       PandocSomeError{} -> 63
       PandocParseError{} -> 64
-      PandocParsecError{} -> 65
       PandocMakePDFError{} -> 66
       PandocSyntaxMapError{} -> 67
       PandocFilterError{} -> 83

src/Text/Pandoc/Parsing.hs

@@ -47,6 +47,7 @@ module Text.Pandoc.Parsing ( module Text.Pandoc.Sources,
                              mathDisplay,
                              withHorizDisplacement,
                              withRaw,
+                             fromParsecError,
                              escaped,
                              characterReference,
                              upperRoman,
@@ -297,7 +298,8 @@ import Text.Pandoc.Parsing.General
       trimInlinesF,
       uri,
       withHorizDisplacement,
-      withRaw )
+      withRaw,
+      fromParsecError )
 import Text.Pandoc.Parsing.GridTable
     ( gridTableWith,
       gridTableWith',

src/Text/Pandoc/Parsing/General.hs

@@ -58,6 +58,7 @@ module Text.Pandoc.Parsing.General
   , uri
   , withHorizDisplacement
   , withRaw
+  , fromParsecError
   )
 where
 
@@ -82,7 +83,8 @@ import Data.Char
   , toUpper
   )
 import Data.Functor (($>))
-import Data.List (intercalate)
+import Data.List (intercalate, sortOn)
+import Data.Ord (Down(..))
 import Data.Maybe (fromMaybe)
 import Data.Text (Text)
 import Text.HTML.TagSoup.Entity (lookupEntity)
@@ -103,6 +105,11 @@ import Text.Parsec
   ( (<|>)
   , ParsecT
   , SourcePos
+  , sourceLine
+  , sourceColumn
+  , sourceName
+  , ParseError
+  , errorPos
   , Stream(..)
   , between
   , choice
@@ -130,7 +137,7 @@ import Text.Parsec
 import Text.Parsec.Pos (initialPos, newPos)
 import Text.Parsec (Parsec)
 import Text.Pandoc.Error
-  ( PandocError(PandocParseError, PandocParsecError) )
+  ( PandocError(PandocParseError) )
 import Text.Pandoc.Parsing.Capabilities
 import Text.Pandoc.Parsing.State
 import Text.Pandoc.Parsing.Future (Future (..))
@@ -623,7 +630,7 @@ readWithM :: (Monad m, ToSources t)
           -> t                       -- ^ input
           -> m (Either PandocError a)
 readWithM parser state input =
-    mapLeft (PandocParsecError sources)
+    mapLeft (fromParsecError sources)
       <$> runParserT parser state (initialSourceName sources) sources
  where
    sources = toSources input
@@ -750,3 +757,28 @@ exciseLines mbstartline mbendline t =
                  Nothing -> numLines
                  Just x | x >= 0 -> x
                         | otherwise -> numLines + x -- negative from end
+
+fromParsecError :: Sources -> ParseError -> PandocError
+fromParsecError (Sources inputs) err' = PandocParseError msg
+ where
+  msg = "Error at " <> tshow  err' <> errorContext
+  errPos = errorPos err'
+  errLine = sourceLine errPos
+  errColumn = sourceColumn errPos
+  errFile = sourceName errPos
+  errorContext =
+    case sortOn (Down . sourceLine . fst)
+            [ (pos,t)
+              | (pos,t) <- inputs
+              , sourceName pos == errFile
+              , sourceLine pos <= errLine
+            ] of
+      []  -> ""
+      ((pos,txt):_) ->
+        let ls = T.lines txt <> [""]
+            ln = (errLine - sourceLine pos) + 1
+         in if length ls > ln && ln >= 1
+               then T.concat ["\n", ls !! (ln - 1)
+                             ,"\n", T.replicate (errColumn - 1) " "
+                             ,"^"]
+               else ""

src/Text/Pandoc/Readers/BibTeX.hs

@@ -23,6 +23,7 @@ where
 import Text.Pandoc.Options
 import Text.Pandoc.Definition
 import Text.Pandoc.Builder (setMeta, cite, str)
+import Text.Pandoc.Parsing (fromParsecError)
 import Citeproc (Lang(..), parseLang)
 import Citeproc.Locale (getLocale)
 import Text.Pandoc.Error (PandocError(..))
@@ -63,7 +64,7 @@ readBibTeX' variant _opts t = do
                    Left _  -> throwError $ PandocCiteprocError e
                Right l -> return l
   case BibTeX.readBibtexString variant locale (const True) t of
-    Left e -> throwError $ PandocParsecError (toSources t) e
+    Left e -> throwError $ fromParsecError (toSources t) e
     Right refs -> return $ setMeta "references"
                               (map referenceToMetaValue refs)
                          . setMeta "nocite"

src/Text/Pandoc/Readers/CSV.hs

@@ -21,11 +21,11 @@ import Text.Pandoc.CSV (parseCSV, defaultCSVOptions, CSVOptions(..))
 import Text.Pandoc.Definition
 import qualified Text.Pandoc.Builder as B
 import Text.Pandoc.Class (PandocMonad)
-import Text.Pandoc.Error
 import Text.Pandoc.Sources (ToSources(..), sourcesToText)
 import Text.Pandoc.Options (ReaderOptions)
 import Control.Monad.Except (throwError)
 import Data.Text (Text)
+import Text.Pandoc.Parsing (fromParsecError)
 
 readCSV :: (PandocMonad m, ToSources a)
         => ReaderOptions -- ^ Reader options
@@ -68,4 +68,4 @@ readCSVWith csvopts txt = do
              aligns = replicate numcols AlignDefault
              widths = replicate numcols ColWidthDefault
     Right []     -> return $ B.doc mempty
-    Left e       -> throwError $ PandocParsecError (toSources [("",txt)]) e
+    Left e       -> throwError $ fromParsecError (toSources [("",txt)]) e

src/Text/Pandoc/Readers/CommonMark.hs

@@ -33,7 +33,8 @@ import Data.Typeable
 import Text.Pandoc.Parsing (runParserT, getInput, getPosition,
                             runF, defaultParserState, option, many1, anyChar,
                             Sources(..), ToSources(..), ParsecT, Future,
-                            sourceName, sourceLine, incSourceLine)
+                            sourceName, sourceLine, incSourceLine,
+                            fromParsecError)
 import Text.Pandoc.Walk (walk)
 import qualified Data.Text as T
 import qualified Data.Attoparsec.Text as A
@@ -95,10 +96,10 @@ readCommonMarkBody opts s toks =
       else id) <$>
   if isEnabled Ext_sourcepos opts
      then case runIdentity (parseCommonmarkWith (specFor opts) toks) of
-            Left err -> throwError $ PandocParsecError s err
+            Left err -> throwError $ fromParsecError s err
             Right (Cm bls :: Cm SourceRange Blocks) -> return $ B.doc bls
      else case runIdentity (parseCommonmarkWith (specFor opts) toks) of
-            Left err -> throwError $ PandocParsecError s err
+            Left err -> throwError $ fromParsecError s err
             Right (Cm bls :: Cm () Blocks) -> return $ B.doc bls
 
 stripBlockComments :: Block -> Block

src/Text/Pandoc/Readers/DokuWiki.hs

@@ -26,7 +26,6 @@ import qualified Data.Text as T
 import qualified Text.Pandoc.Builder as B
 import Text.Pandoc.Class.PandocMonad (PandocMonad (..))
 import Text.Pandoc.Definition
-import Text.Pandoc.Error (PandocError (PandocParsecError))
 import Text.Pandoc.Options
 import Text.Pandoc.Parsing hiding (enclosed, nested)
 import Text.Pandoc.Shared (trim, stringify, tshow)
@@ -43,7 +42,7 @@ readDokuWiki opts s = do
   res <- runParserT parseDokuWiki def {stateOptions = opts }
            (initialSourceName sources) sources
   case res of
-       Left e  -> throwError $ PandocParsecError sources e
+       Left e  -> throwError $ fromParsecError sources e
        Right d -> return d
 
 type DWParser = ParsecT Sources ParserState

src/Text/Pandoc/Readers/LaTeX.hs

@@ -40,7 +40,7 @@ import Text.Pandoc.Class (PandocPure, PandocMonad (..), getResourcePath,
                           readFileFromDirs, report,
                           setResourcePath, getZonedTime)
 import Data.Time (ZonedTime(..), LocalTime(..), showGregorian)
-import Text.Pandoc.Error (PandocError (PandocParseError, PandocParsecError))
+import Text.Pandoc.Error (PandocError (PandocParseError))
 import Text.Pandoc.Highlighting (languagesByExtension)
 import Text.Pandoc.ImageSize (numUnit, showFl)
 import Text.Pandoc.Logging
@@ -87,7 +87,7 @@ readLaTeX opts ltx = do
                (TokStream False (tokenizeSources sources))
   case parsed of
     Right result -> return result
-    Left e       -> throwError $ PandocParsecError sources e
+    Left e       -> throwError $ fromParsecError sources e
 
 parseLaTeX :: PandocMonad m => LP m Pandoc
 parseLaTeX = do
@@ -669,7 +669,7 @@ opt = do
               (TokStream False toks)
   case parsed of
     Right result -> return result
-    Left e       -> throwError $ PandocParsecError (toSources toks) e
+    Left e       -> throwError $ fromParsecError (toSources toks) e
 
 -- block elements:
 

src/Text/Pandoc/Readers/LaTeX/Citation.hs

@@ -15,7 +15,6 @@ import Control.Applicative ((<|>), optional, many)
 import Control.Monad (mzero)
 import Control.Monad.Trans (lift)
 import Control.Monad.Except (throwError)
-import Text.Pandoc.Error (PandocError(PandocParsecError))
 import Text.Pandoc.Parsing hiding (blankline, many, mathDisplay, mathInline,
                             optional, space, spaces, withRaw, (<|>))
 
@@ -121,7 +120,7 @@ simpleCiteArgs inline = try $ do
        (TokStream False toks)
     case parsed of
       Right result -> return result
-      Left e       -> throwError $ PandocParsecError (toSources toks) e
+      Left e       -> throwError $ fromParsecError (toSources toks) e
 
 
 

src/Text/Pandoc/Readers/Man.hs

@@ -16,7 +16,7 @@ module Text.Pandoc.Readers.Man (readMan) where
 
 import Data.Char (toLower)
 import Data.Default (Default)
-import Control.Monad (liftM, mzero, guard, void)
+import Control.Monad (mzero, guard, void)
 import Control.Monad.Trans (lift)
 import Control.Monad.Except (throwError)
 import Data.Maybe (catMaybes, isJust)
@@ -24,12 +24,10 @@ import Data.List (intersperse)
 import qualified Data.Text as T
 import Text.Pandoc.Builder as B
 import Text.Pandoc.Class.PandocMonad (PandocMonad(..), report)
-import Text.Pandoc.Error (PandocError (PandocParsecError))
 import Text.Pandoc.Logging (LogMessage(..))
 import Text.Pandoc.Options
 import Text.Pandoc.Parsing
 import Text.Pandoc.Walk (query)
-import Text.Pandoc.Shared (mapLeft)
 import Text.Pandoc.Readers.Roff  -- TODO explicit imports
 import qualified Text.Pandoc.Parsing as P
 import qualified Data.Foldable as Foldable
@@ -56,21 +54,18 @@ readMan opts s = do
   let Sources inps = toSources s
   tokenz <- mconcat <$> mapM (uncurry lexRoff) inps
   let state = def {readerOptions = opts} :: ManState
-  let fixError (PandocParsecError _ e) = PandocParsecError (Sources inps) e
-      fixError e = e
   eitherdoc <- readWithMTokens parseMan state
      (Foldable.toList . unRoffTokens $ tokenz)
-  either (throwError . fixError) return eitherdoc
+  either (throwError . fromParsecError (Sources inps)) return eitherdoc
 
 
 readWithMTokens :: PandocMonad m
         => ParsecT [RoffToken] ManState m a  -- ^ parser
         -> ManState                         -- ^ initial state
         -> [RoffToken]                       -- ^ input
-        -> m (Either PandocError a)
+        -> m (Either ParseError a)
 readWithMTokens parser state input =
-  let leftF = PandocParsecError mempty
-  in mapLeft leftF `liftM` runParserT parser state "source" input
+  runParserT parser state "source" input
 
 
 parseMan :: PandocMonad m => ManParser m Pandoc

src/Text/Pandoc/Readers/Muse.hs

@@ -33,7 +33,6 @@ import Text.Pandoc.Builder (Blocks, Inlines, underline)
 import qualified Text.Pandoc.Builder as B
 import Text.Pandoc.Class.PandocMonad (PandocMonad (..))
 import Text.Pandoc.Definition
-import Text.Pandoc.Error (PandocError (PandocParsecError))
 import Text.Pandoc.Logging
 import Text.Pandoc.Options
 import Text.Pandoc.Parsing
@@ -49,7 +48,7 @@ readMuse opts s = do
   res <- flip runReaderT def $ runParserT parseMuse def{ museOptions = opts }
               (initialSourceName sources) sources
   case res of
-       Left e  -> throwError $ PandocParsecError sources e
+       Left e  -> throwError $ fromParsecError sources e
        Right d -> return d
 
 type F = Future MuseState

src/Text/Pandoc/Readers/RST.hs

@@ -871,7 +871,7 @@ csvTableDirective top fields rawcsv = do
   let res = parseCSV opts rawcsv'
   case (<>) <$> header' <*> res of
        Left e  ->
-         throwError $ PandocParsecError "csv table" e
+         throwError $ fromParsecError (toSources rawcsv') e
        Right rawrows -> do
          let singleParaToPlain bs =
                case B.toList bs of