Fix hlint suggestions, update hlint.yaml

.hlint.yaml

@@ -74,8 +74,10 @@
 - ignore:
     name: "Use camelCase"
     within:
+      - Tests.Writers.Docbook
+      - Tests.Writers.Native
       - Text.Pandoc.Extensions
-      - Text.Pandoc.Lua.Marshalling.Version
+      - Text.Pandoc.Lua.Marshaling.Version
       - Text.Pandoc.Readers.Odt.ContentReader
       - Text.Pandoc.Readers.Odt.Namespaces
 

benchmark/weigh-pandoc.hs

@@ -42,7 +42,7 @@ weighWriter :: Pandoc -> String -> (Pandoc -> Text) -> Weigh ()
 weighWriter doc name writer = func (name ++ " writer") writer doc
 
 weighReader :: Pandoc -> Text -> (Text -> Pandoc) -> Weigh ()
-weighReader doc name reader = do
+weighReader doc name reader =
   case lookup name writers of
        Just (TextWriter writer) ->
          let inp = either (error . show) id $ runPure $ writer def{ writerWrapText = WrapAuto} doc

src/Text/Pandoc/App/CommandLineOptions.hs

@@ -1,4 +1,5 @@
 {-# LANGUAGE CPP                 #-}
+{-# LANGUAGE LambdaCase          #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TupleSections       #-}
 {-# LANGUAGE OverloadedStrings   #-}
@@ -868,9 +869,7 @@ options =
     , Option "" ["print-highlight-style"]
                  (ReqArg
                   (\arg opt -> do
-                     let write = case optOutputFile opt of
-                                        Just f  -> B.writeFile f
-                                        Nothing -> B.putStr
+                     let write = maybe B.putStr B.writeFile $ optOutputFile opt
                      sty <- runIOorExplode $ lookupHighlightStyle arg
                      write $ encodePretty'
                        defConfig{confIndent = Spaces 4
@@ -1017,7 +1016,7 @@ lookupHighlightStyle s
 deprecatedOption :: String -> String -> IO ()
 deprecatedOption o msg =
   runIO (report $ Deprecated (T.pack o) (T.pack msg)) >>=
-    \r -> case r of
+    \case
        Right () -> return ()
        Left e   -> E.throwIO e
 

src/Text/Pandoc/Class/PandocMonad.hs

@@ -433,7 +433,7 @@ getDefaultReferenceDocx = do
                "word/theme/theme1.xml"]
   let toLazy = BL.fromChunks . (:[])
   let pathToEntry path = do
-        epochtime <- (floor . utcTimeToPOSIXSeconds) <$> getCurrentTime
+        epochtime <- floor . utcTimeToPOSIXSeconds <$> getCurrentTime
         contents <- toLazy <$> readDataFile ("docx/" ++ path)
         return $ toEntry path epochtime contents
   datadir <- getUserDataDir
@@ -536,7 +536,7 @@ getDefaultReferencePptx = do
               ]
   let toLazy = BL.fromChunks . (:[])
   let pathToEntry path = do
-        epochtime <- (floor . utcTimeToPOSIXSeconds) <$> getCurrentTime
+        epochtime <- floor . utcTimeToPOSIXSeconds <$> getCurrentTime
         contents <- toLazy <$> readDataFile ("pptx/" ++ path)
         return $ toEntry path epochtime contents
   datadir <- getUserDataDir
@@ -568,11 +568,11 @@ readDataFile fname = do
 -- | Read file from from Cabal data directory.
 readDefaultDataFile :: PandocMonad m => FilePath -> m B.ByteString
 readDefaultDataFile "reference.docx" =
-  (B.concat . BL.toChunks . fromArchive) <$> getDefaultReferenceDocx
+  B.concat . BL.toChunks . fromArchive <$> getDefaultReferenceDocx
 readDefaultDataFile "reference.pptx" =
-  (B.concat . BL.toChunks . fromArchive) <$> getDefaultReferencePptx
+  B.concat . BL.toChunks . fromArchive <$> getDefaultReferencePptx
 readDefaultDataFile "reference.odt" =
-  (B.concat . BL.toChunks . fromArchive) <$> getDefaultReferenceODT
+  B.concat . BL.toChunks . fromArchive <$> getDefaultReferenceODT
 readDefaultDataFile fname =
 #ifdef EMBED_DATA_FILES
   case lookup (makeCanonical fname) dataFiles of

src/Text/Pandoc/Image.hs

@@ -1,5 +1,4 @@
 {-# LANGUAGE OverloadedStrings, ScopedTypeVariables, CPP #-}
-{-# LANGUAGE ViewPatterns      #-}
 {- |
 Module      : Text.Pandoc.Image
 Copyright   : Copyright (C) 2020 John MacFarlane

src/Text/Pandoc/Logging.hs

@@ -1,5 +1,6 @@
 {-# LANGUAGE DeriveDataTypeable #-}
 {-# LANGUAGE DeriveGeneric      #-}
+{-# LANGUAGE LambdaCase         #-}
 {-# LANGUAGE OverloadedStrings  #-}
 {- |
    Module      : Text.Pandoc.Logging
@@ -51,8 +52,7 @@ instance FromJSON Verbosity where
   parseJSON _      =  mzero
 
 instance FromYAML Verbosity where
-  parseYAML = withStr "Verbosity" $ \t ->
-    case t of
+  parseYAML = withStr "Verbosity" $ \case
          "ERROR"   -> return ERROR
          "WARNING" -> return WARNING
          "INFO"    -> return INFO

src/Text/Pandoc/Lua/Marshaling/AST.hs

@@ -230,9 +230,7 @@ peekCaption idx = do
 instance Peekable ColWidth where
   peek idx = do
     width <- Lua.fromOptional <$> Lua.peek idx
-    return $ case width of
-      Nothing -> ColWidthDefault
-      Just w  -> ColWidth w
+    return $ maybe ColWidthDefault ColWidth width
 
 instance Pushable ColWidth where
   push = \case

src/Text/Pandoc/Lua/Module/Utils.hs

@@ -50,9 +50,8 @@ pushModule = do
 -- | Squashes a list of blocks into inlines.
 blocksToInlines :: [Block] -> Lua.Optional [Inline] -> PandocLua [Inline]
 blocksToInlines blks optSep = liftPandocLua $ do
-  let sep = case Lua.fromOptional optSep of
-              Just x -> B.fromList x
-              Nothing -> Shared.defaultBlocksSeparator
+  let sep = maybe Shared.defaultBlocksSeparator B.fromList
+            $ Lua.fromOptional optSep
   return $ B.toList (Shared.blocksToInlinesWithSep sep blks)
 
 -- | Convert list of Pandoc blocks into sections using Divs.

src/Text/Pandoc/Options.hs

@@ -1,8 +1,9 @@
 {-# LANGUAGE CPP                #-}
 {-# LANGUAGE DeriveDataTypeable #-}
 {-# LANGUAGE DeriveGeneric      #-}
-{-# LANGUAGE TemplateHaskell    #-}
+{-# LANGUAGE LambdaCase         #-}
 {-# LANGUAGE OverloadedStrings  #-}
+{-# LANGUAGE TemplateHaskell    #-}
 {- |
    Module      : Text.Pandoc.Options
    Copyright   : Copyright (C) 2012-2020 John MacFarlane
@@ -327,7 +328,7 @@ $(deriveJSON defaultOptions{ constructorTagModifier =
                            } ''CiteMethod)
 
 $(deriveJSON defaultOptions{ constructorTagModifier =
-                            \t -> case t of
+                            \case
                                     "NoObfuscation"         -> "none"
                                     "ReferenceObfuscation"  -> "references"
                                     "JavascriptObfuscation" -> "javascript"

src/Text/Pandoc/PDF.hs

@@ -1,4 +1,5 @@
 {-# LANGUAGE CPP                 #-}
+{-# LANGUAGE LambdaCase          #-}
 {-# LANGUAGE OverloadedStrings   #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {- |
@@ -201,8 +202,7 @@ convertImage opts tmpdir fname = do
       (\(e :: E.SomeException) -> return $ Left $
           "check that rsvg-convert is in path.\n" <>
           tshow e)
-    _ -> JP.readImage fname >>= \res ->
-          case res of
+    _ -> JP.readImage fname >>= \case
                Left e    -> return $ Left $ T.pack e
                Right img ->
                  E.catch (Right pngOut <$ JP.savePngImage pngOut img) $

src/Text/Pandoc/Parsing.hs

@@ -574,15 +574,15 @@ romanNumeral upperCase = do
     let fivehundred = rchar 'D'
     let thousand    = rchar 'M'
     lookAhead $ choice [one, five, ten, fifty, hundred, fivehundred, thousand]
-    thousands <- ((1000 *) . length) <$> many thousand
+    thousands <- (1000 *) . length <$> many thousand
     ninehundreds <- option 0 $ try $ hundred >> thousand >> return 900
     fivehundreds <- option 0 $ 500 <$ fivehundred
     fourhundreds <- option 0 $ try $ hundred >> fivehundred >> return 400
-    hundreds <- ((100 *) . length) <$> many hundred
+    hundreds <- (100 *) . length <$> many hundred
     nineties <- option 0 $ try $ ten >> hundred >> return 90
     fifties <- option 0 (50 <$ fifty)
     forties <- option 0 $ try $ ten >> fifty >> return 40
-    tens <- ((10 *) . length) <$> many ten
+    tens <- (10 *) . length <$> many ten
     nines <- option 0 $ try $ one >> ten >> return 9
     fives <- option 0 (5 <$ five)
     fours <- option 0 $ try $ one >> five >> return 4
@@ -951,7 +951,7 @@ tableWith' headerParser rowParser lineParser footerParser = try $ do
                     then replicate (length aligns) 0.0
                     else widthsFromIndices numColumns indices
     let toRow =  Row nullAttr . map B.simpleCell
-        toHeaderRow l = if null l then [] else [toRow l]
+        toHeaderRow l = [toRow l | not (null l)]
     return (aligns, widths, toHeaderRow <$> heads, map toRow <$> lines')
 
 -- Calculate relative widths of table columns, based on indices
@@ -1170,7 +1170,7 @@ class HasReaderOptions st where
   extractReaderOptions :: st -> ReaderOptions
   getOption            :: (Stream s m t) => (ReaderOptions -> b) -> ParserT s st m b
   -- default
-  getOption  f         = (f . extractReaderOptions) <$> getState
+  getOption  f         = f . extractReaderOptions <$> getState
 
 instance HasReaderOptions ParserState where
   extractReaderOptions = stateOptions
@@ -1492,10 +1492,8 @@ extractIdClass :: Attr -> Attr
 extractIdClass (ident, cls, kvs) = (ident', cls', kvs')
   where
     ident' = fromMaybe ident (lookup "id" kvs)
-    cls'   = case lookup "class" kvs of
-               Just cl -> T.words cl
-               Nothing -> cls
-    kvs'  = filter (\(k,_) -> k /= "id" || k /= "class") kvs
+    cls'   = maybe cls T.words $ lookup "class" kvs
+    kvs'   = filter (\(k,_) -> k /= "id" || k /= "class") kvs
 
 insertIncludedFile' :: (PandocMonad m, HasIncludeFiles st)
                     => ParserT a st m (mf Blocks)

src/Text/Pandoc/Readers/CSV.hs

@@ -39,7 +39,7 @@ readCSV _opts s =
              numcols = length r
              toplain = B.simpleCell . B.plain . B.text . T.strip
              toRow = Row nullAttr . map toplain
-             toHeaderRow l = if null l then [] else [toRow l]
+             toHeaderRow l = [toRow l | not (null l)]
              hdrs = toHeaderRow r
              rows = map toRow rs
              aligns = replicate numcols AlignDefault

src/Text/Pandoc/Readers/CommonMark.hs

@@ -1,6 +1,5 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE ViewPatterns      #-}
 {- |
    Module      : Text.Pandoc.Readers.CommonMark
    Copyright   : Copyright (C) 2015-2020 John MacFarlane

src/Text/Pandoc/Readers/DocBook.hs

@@ -18,7 +18,7 @@ import Data.Either (rights)
 import Data.Foldable (asum)
 import Data.Generics
 import Data.List (intersperse,elemIndex)
-import Data.Maybe (fromMaybe,catMaybes)
+import Data.Maybe (fromMaybe,mapMaybe)
 import Data.Text (Text)
 import qualified Data.Text as T
 import Text.HTML.TagSoup.Entity (lookupEntity)
@@ -781,7 +781,7 @@ parseBlock (Elem e) =
         "para"  -> parseMixed para (elContent e)
         "formalpara" -> do
            tit <- case filterChild (named "title") e of
-                        Just t  -> (para . strong . (<> str ".")) <$>
+                        Just t  -> para . strong . (<> str ".") <$>
                                      getInlines t
                         Nothing -> return mempty
            (tit <>) <$> parseMixed para (elContent e)
@@ -897,7 +897,7 @@ parseBlock (Elem e) =
          parseBlockquote = do
             attrib <- case filterChild (named "attribution") e of
                              Nothing  -> return mempty
-                             Just z   -> (para . (str "— " <>) . mconcat)
+                             Just z   -> para . (str "— " <>) . mconcat
                                          <$>
                                               mapM parseInline (elContent z)
             contents <- getBlocks e
@@ -931,7 +931,7 @@ parseBlock (Elem e) =
                                            _      -> filterChildren isColspec e'
                       let colnames = case colspecs of
                                        [] -> []
-                                       cs -> catMaybes $ map (findAttr (unqual "colname" )) cs
+                                       cs -> mapMaybe (findAttr (unqual "colname" )) cs
                       let isRow x = named "row" x || named "tr" x
                       headrows <- case filterChild (named "thead") e' of
                                        Just h  -> case filterChild isRow h of
@@ -968,7 +968,7 @@ parseBlock (Elem e) =
                                                             in  ColWidth . (/ tot) <$> ws'
                                                 Nothing  -> replicate numrows ColWidthDefault
                       let toRow = Row nullAttr
-                          toHeaderRow l = if null l then [] else [toRow l]
+                          toHeaderRow l = [toRow l | not (null l)]
                       return $ table (simpleCaption $ plain capt)
                                      (zip aligns widths)
                                      (TableHead nullAttr $ toHeaderRow headrows)
@@ -1008,7 +1008,7 @@ parseBlock (Elem e) =
 parseMixed :: PandocMonad m => (Inlines -> Blocks) -> [Content] -> DB m Blocks
 parseMixed container conts = do
   let (ils,rest) = break isBlockElement conts
-  ils' <- (trimInlines . mconcat) <$> mapM parseInline ils
+  ils' <- trimInlines . mconcat <$> mapM parseInline ils
   let p = if ils' == mempty then mempty else container ils'
   case rest of
     [] -> return p
@@ -1036,10 +1036,10 @@ parseEntry cn el = do
         case (mStrt, mEnd) of
           (Just start, Just end) -> colDistance start end
           _ -> 1
-  (fmap (cell AlignDefault 1 (toColSpan el)) . (parseMixed plain) . elContent) el
+  (fmap (cell AlignDefault 1 (toColSpan el)) . parseMixed plain . elContent) el
 
 getInlines :: PandocMonad m => Element -> DB m Inlines
-getInlines e' = (trimInlines . mconcat) <$>
+getInlines e' = trimInlines . mconcat <$>
                  mapM parseInline (elContent e')
 
 strContentRecursive :: Element -> String
@@ -1136,7 +1136,7 @@ parseInline (Elem e) =
                              "strong"        -> strong <$> innerInlines
                              "strikethrough" -> strikeout <$> innerInlines
                              _               -> emph <$> innerInlines
-        "footnote" -> (note . mconcat) <$>
+        "footnote" -> note . mconcat <$>
                          mapM parseBlock (elContent e)
         "title" -> return mempty
         "affiliation" -> skip
@@ -1149,14 +1149,14 @@ parseInline (Elem e) =
            lift $ report $ IgnoredElement $ T.pack $ qName (elName e)
            return mempty
 
-         innerInlines = (trimInlines . mconcat) <$>
+         innerInlines = trimInlines . mconcat <$>
                           mapM parseInline (elContent e)
          codeWithLang = do
            let classes' = case attrValue "language" e of
                                "" -> []
                                l  -> [l]
            return $ codeWith (attrValue "id" e,classes',[]) $ T.pack $ strContentRecursive e
-         simpleList = (mconcat . intersperse (str "," <> space)) <$> mapM getInlines
+         simpleList = mconcat . intersperse (str "," <> space) <$> mapM getInlines
                          (filterChildren (named "member") e)
          segmentedList = do
            tit <- maybe (return mempty) getInlines $ filterChild (named "title") e

src/Text/Pandoc/Readers/Docx.hs

@@ -91,9 +91,9 @@ readDocx :: PandocMonad m
          => ReaderOptions
          -> B.ByteString
          -> m Pandoc
-readDocx opts bytes = do
+readDocx opts bytes =
   case toArchiveOrFail bytes of
-    Right archive -> do
+    Right archive ->
       case archiveToDocxWithWarnings archive of
         Right (docx, parserWarnings) -> do
           mapM_ (P.report . DocxParserWarning) parserWarnings
@@ -291,9 +291,9 @@ runStyleToTransform rPr' = do
             spanWith ("",[],[("dir","ltr")]) . go rPr{isRTL = Nothing}
         | Just SupScrpt <- rVertAlign rPr =
             superscript . go rPr{rVertAlign = Nothing}
-        | Just SubScrpt <- rVertAlign rPr = do
+        | Just SubScrpt <- rVertAlign rPr =
             subscript . go rPr{rVertAlign = Nothing}
-        | Just "single" <- rUnderline rPr = do
+        | Just "single" <- rUnderline rPr =
             Pandoc.underline . go rPr{rUnderline = Nothing}
         | otherwise = id
   return $ go rPr'
@@ -658,7 +658,7 @@ bodyPartToBlocks (Tbl cap _ look parts@(r:rs)) = do
       rowLength (Docx.Row c) = length c
 
   let toRow = Pandoc.Row nullAttr . map simpleCell
-      toHeaderRow l = if null l then [] else [toRow l]
+      toHeaderRow l = [toRow l | not (null l)]
 
   -- pad cells.  New Text.Pandoc.Builder will do that for us,
   -- so this is for compatibility while we switch over.

src/Text/Pandoc/Readers/Docx/Parse.hs

@@ -404,12 +404,8 @@ archiveToNotes zf =
                >>= (parseXMLDoc . UTF8.toStringLazy . fromEntry)
       enElem = findEntryByPath "word/endnotes.xml" zf
                >>= (parseXMLDoc . UTF8.toStringLazy . fromEntry)
-      fn_namespaces = case fnElem of
-        Just e  -> elemToNameSpaces e
-        Nothing -> []
-      en_namespaces = case enElem of
-        Just e  -> elemToNameSpaces e
-        Nothing -> []
+      fn_namespaces = maybe [] elemToNameSpaces fnElem
+      en_namespaces = maybe [] elemToNameSpaces enElem
       ns = unionBy (\x y -> fst x == fst y) fn_namespaces en_namespaces
       fn = fnElem >>= walkDocument ns >>= elemToNotes ns "footnote"
       en = enElem >>= walkDocument ns >>= elemToNotes ns "endnote"
@@ -420,9 +416,7 @@ archiveToComments :: Archive -> Comments
 archiveToComments zf =
   let cmtsElem = findEntryByPath "word/comments.xml" zf
                >>= (parseXMLDoc . UTF8.toStringLazy . fromEntry)
-      cmts_namespaces = case cmtsElem of
-        Just e  -> elemToNameSpaces e
-        Nothing -> []
+      cmts_namespaces = maybe [] elemToNameSpaces cmtsElem
       cmts = elemToComments cmts_namespaces <$> (cmtsElem >>= walkDocument cmts_namespaces)
   in
     case cmts of

src/Text/Pandoc/Readers/DokuWiki.hs

@@ -472,7 +472,7 @@ table = do
                             else ([], rows)
   let attrs = (AlignDefault, ColWidthDefault) <$ transpose rows
   let toRow = Row nullAttr . map B.simpleCell
-      toHeaderRow l = if null l then [] else [toRow l]
+      toHeaderRow l = [toRow l | not (null l)]
   pure $ B.table B.emptyCaption
                  attrs
                  (TableHead nullAttr $ toHeaderRow headerRow)

src/Text/Pandoc/Readers/HTML.hs

@@ -517,7 +517,7 @@ pTable = try $ do
                        else replicate cols (ColWidth (1.0 / fromIntegral cols))
                   else widths'
   let toRow = Row nullAttr . map B.simpleCell
-      toHeaderRow l = if null l then [] else [toRow l]
+      toHeaderRow l = [toRow l | not (null l)]
   return $ B.tableWith attribs
                    (B.simpleCaption $ B.plain caption)
                    (zip aligns widths)