Improve code style in lua and org modules

src/Text/Pandoc/Lua.hs

@@ -15,8 +15,8 @@ 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
 -}
-{-# LANGUAGE FlexibleContexts #-}
-{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE FlexibleContexts      #-}
+{-# LANGUAGE FlexibleInstances     #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {- |
    Module      : Text.Pandoc.Lua
@@ -30,12 +30,12 @@ Pandoc lua utils.
 -}
 module Text.Pandoc.Lua ( runLuaFilter, pushPandocModule ) where
 
-import Control.Monad ( (>=>), when )
-import Control.Monad.Trans ( MonadIO(..) )
-import Data.Map ( Map )
-import Scripting.Lua ( LuaState, StackValue(..) )
+import Control.Monad (unless, when, (>=>))
+import Control.Monad.Trans (MonadIO (..))
+import Data.Map (Map)
+import Scripting.Lua (LuaState, StackValue (..))
 import Text.Pandoc.Definition
-import Text.Pandoc.Lua.PandocModule ( pushPandocModule )
+import Text.Pandoc.Lua.PandocModule (pushPandocModule)
 import Text.Pandoc.Lua.StackInstances ()
 import Text.Pandoc.Walk
 
@@ -80,7 +80,7 @@ pushGlobalFilter lua =
   *> Lua.rawseti lua (-2) 1
 
 runAll :: [LuaFilter] -> Pandoc -> IO Pandoc
-runAll [] = return
+runAll []     = return
 runAll (x:xs) = walkMWithLuaFilter x >=> runAll xs
 
 walkMWithLuaFilter :: LuaFilter -> Pandoc -> IO Pandoc
@@ -225,7 +225,7 @@ instance StackValue LuaFilterFunction where
   push lua v = pushFilterFunction lua v
   peek lua i = do
     isFn <- Lua.isfunction lua i
-    when (not isFn) (error $ "Not a function at index " ++ (show i))
+    unless isFn (error $ "Not a function at index " ++ (show i))
     Lua.pushvalue lua i
     push lua ("PANDOC_FILTER_FUNCTIONS"::String)
     Lua.rawget lua Lua.registryindex

src/Text/Pandoc/Lua/Compat.hs

@@ -28,13 +28,13 @@ Compatibility helpers for hslua
 -}
 module Text.Pandoc.Lua.Compat ( loadstring ) where
 
-import Scripting.Lua ( LuaState )
+import Scripting.Lua (LuaState)
 import qualified Scripting.Lua as Lua
 
 -- | Interpret string as lua code and load into the lua environment.
 loadstring :: LuaState -> String -> String -> IO Int
 #if MIN_VERSION_hslua(0,5,0)
-loadstring lua script _ = Lua.loadstring lua script
+loadstring lua script _  = Lua.loadstring lua script
 #else
 loadstring lua script cn = Lua.loadstring lua script cn
 #endif

src/Text/Pandoc/Lua/PandocModule.hs

@@ -27,25 +27,23 @@ Pandoc module for lua.
 -}
 module Text.Pandoc.Lua.PandocModule ( pushPandocModule ) where
 
-import Data.ByteString.Char8 ( unpack )
-import Data.Default ( Default(..) )
-import Scripting.Lua ( LuaState, call, push, pushhsfunction, rawset)
-import Text.Pandoc.Class hiding ( readDataFile )
-import Text.Pandoc.Definition ( Pandoc )
-import Text.Pandoc.Lua.Compat ( loadstring )
+import Control.Monad (unless)
+import Data.ByteString.Char8 (unpack)
+import Data.Default (Default (..))
+import Scripting.Lua (LuaState, call, push, pushhsfunction, rawset)
+import Text.Pandoc.Class hiding (readDataFile)
+import Text.Pandoc.Definition (Pandoc)
+import Text.Pandoc.Lua.Compat (loadstring)
 import Text.Pandoc.Lua.StackInstances ()
-import Text.Pandoc.Readers ( Reader(..), getReader )
-import Text.Pandoc.Shared ( readDataFile )
+import Text.Pandoc.Readers (Reader (..), getReader)
+import Text.Pandoc.Shared (readDataFile)
 
 -- | Push the "pandoc" on the lua stack.
 pushPandocModule :: LuaState -> IO ()
 pushPandocModule lua = do
   script <- pandocModuleScript
   status <- loadstring lua script "pandoc.lua"
-  if (status /= 0)
-    then return ()
-    else do
-      call lua 0 1
+  unless (status /= 0) $ call lua 0 1
   push lua "__read"
   pushhsfunction lua read_doc
   rawset lua (-3)
@@ -57,13 +55,13 @@ pandocModuleScript = unpack <$> readDataFile Nothing "pandoc.lua"
 read_doc :: String -> String -> IO (Either String Pandoc)
 read_doc formatSpec content = do
   case getReader formatSpec of
-    Left s -> return $ Left s
+    Left  s      -> return $ Left s
     Right reader ->
       case reader of
         StringReader r -> do
           res <- runIO $ r def content
           case res of
-            Left s -> return . Left $ show s
+            Left s   -> return . Left $ show s
             Right pd -> return $ Right pd
         _  -> return $ Left "Only string formats are supported at the moment."
 

src/Text/Pandoc/Lua/SharedInstances.hs

@@ -16,9 +16,9 @@ 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
 -}
-{-# LANGUAGE CPP #-}
-{-# LANGUAGE FlexibleInstances #-}
-{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE CPP                  #-}
+{-# LANGUAGE FlexibleInstances    #-}
+{-# LANGUAGE LambdaCase           #-}
 #if !MIN_VERSION_base(4,8,0)
 {-# LANGUAGE OverlappingInstances #-}
 #endif
@@ -36,8 +36,8 @@ Shared StackValue instances for pandoc and generic types.
 -}
 module Text.Pandoc.Lua.SharedInstances () where
 
-import Scripting.Lua ( LTYPE(..), StackValue(..), newtable )
-import Text.Pandoc.Lua.Util ( addRawInt, addValue, getRawInt, keyValuePairs )
+import Scripting.Lua (LTYPE (..), StackValue (..), newtable)
+import Text.Pandoc.Lua.Util (addRawInt, addValue, getRawInt, keyValuePairs)
 
 import qualified Data.Map as M
 import qualified Text.Pandoc.UTF8 as UTF8
@@ -112,5 +112,5 @@ instance (StackValue a, StackValue b) => StackValue (Either a b) where
   peek lua idx = peek lua idx >>= \case
       Just left -> return . Just $ Left left
       Nothing   -> fmap Right <$> peek lua idx
-  valuetype (Left x) = valuetype x
+  valuetype (Left x)  = valuetype x
   valuetype (Right x) = valuetype x

src/Text/Pandoc/Lua/StackInstances.hs

@@ -17,7 +17,7 @@ along with this program; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 -}
 {-# LANGUAGE FlexibleInstances #-}
-{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE LambdaCase        #-}
 {-# OPTIONS_GHC -fno-warn-orphans #-}
 {- |
    Module      : Text.Pandoc.Lua.StackInstances
@@ -32,13 +32,13 @@ StackValue instances for pandoc types.
 -}
 module Text.Pandoc.Lua.StackInstances () where
 
-import Control.Applicative ( (<|>) )
-import Scripting.Lua
-  ( LTYPE(..), LuaState, StackValue(..), ltype, newtable, objlen )
+import Control.Applicative ((<|>))
+import Scripting.Lua (LTYPE (..), LuaState, StackValue (..), ltype, newtable,
+                      objlen)
 import Text.Pandoc.Definition
 import Text.Pandoc.Lua.SharedInstances ()
-import Text.Pandoc.Lua.Util ( addValue, getTable, pushViaConstructor )
-import Text.Pandoc.Shared ( safeRead )
+import Text.Pandoc.Lua.Util (addValue, getTable, pushViaConstructor)
+import Text.Pandoc.Shared (safeRead)
 
 instance StackValue Pandoc where
   push lua (Pandoc meta blocks) = do

src/Text/Pandoc/Lua/Util.hs

@@ -42,10 +42,8 @@ module Text.Pandoc.Lua.Util
   , pushViaConstructor
   ) where
 
-import Scripting.Lua
-  ( LuaState, StackValue(..)
-  , call, getglobal2, gettable, next, pop, pushnil, rawgeti, rawseti, settable
-  )
+import Scripting.Lua (LuaState, StackValue (..), call, getglobal2, gettable,
+                      next, pop, pushnil, rawgeti, rawseti, settable)
 
 -- | Adjust the stack index, assuming that @n@ new elements have been pushed on
 -- the stack.

src/Text/Pandoc/Readers/Org/Blocks.hs

@@ -351,7 +351,7 @@ switchesAsAttributes = try $ do
                 Just num -> ("startFrom", num):kv
                 Nothing  -> kv
         cls' = case pol of
-                 SwitchPlus -> "continuedSourceBlock":cls
+                 SwitchPlus  -> "continuedSourceBlock":cls
                  SwitchMinus -> cls
     in ("numberLines":cls', kv')
   addToAttr _ x = x

src/Text/Pandoc/Readers/Org/DocumentTree.hs

@@ -35,14 +35,14 @@ module Text.Pandoc.Readers.Org.DocumentTree
 import Control.Arrow ((***))
 import Control.Monad (guard, void)
 import Data.Char (toLower, toUpper)
-import Data.List ( intersperse )
+import Data.List (intersperse)
 import Data.Monoid ((<>))
 import Text.Pandoc.Builder (Blocks, Inlines)
 import Text.Pandoc.Class (PandocMonad)
 import Text.Pandoc.Definition
 import Text.Pandoc.Readers.Org.BlockStarts
-import Text.Pandoc.Readers.Org.Parsing
 import Text.Pandoc.Readers.Org.ParserState
+import Text.Pandoc.Readers.Org.Parsing
 
 import qualified Data.Map as Map
 import qualified Text.Pandoc.Builder as B
@@ -78,7 +78,7 @@ documentTree blocks inline = do
   getTitle metamap =
     case Map.lookup "title" metamap of
       Just (MetaInlines inlns) -> inlns
-      _ -> []
+      _                        -> []
 
 newtype Tag = Tag { fromTag :: String }
   deriving (Show, Eq)

src/Text/Pandoc/Readers/Org/Inlines.hs

@@ -343,11 +343,10 @@ orgRefCiteKey =
   let citeKeySpecialChars = "-_:\\./," :: String
       isCiteKeySpecialChar c = c `elem` citeKeySpecialChars
       isCiteKeyChar c = isAlphaNum c || isCiteKeySpecialChar c
-
-  in try $ many1Till (satisfy isCiteKeyChar)
-           $ try . lookAhead $ do
-               many . satisfy $ isCiteKeySpecialChar
-               satisfy $ not . isCiteKeyChar
+      endOfCitation = try $ do
+        many $ satisfy isCiteKeySpecialChar
+        satisfy $ not . isCiteKeyChar
+  in try $ satisfy isCiteKeyChar `many1Till` lookAhead endOfCitation
 
 
 -- | Supported citation types.  Only a small subset of org-ref types is
@@ -415,7 +414,7 @@ referencedNote = try $ do
   return $ do
     notes <- asksF orgStateNotes'
     case lookup ref notes of
-      Nothing   -> return $ B.str $ "[" ++ ref ++ "]"
+      Nothing   -> return . B.str $ "[" ++ ref ++ "]"
       Just contents  -> do
         st <- askF
         let contents' = runF contents st{ orgStateNotes' = [] }
@@ -439,7 +438,7 @@ explicitOrImageLink = try $ do
     src <- srcF
     case cleanLinkString title of
       Just imgSrc | isImageFilename imgSrc ->
-        pure $ B.link src "" $ B.image imgSrc mempty mempty
+        pure . B.link src "" $ B.image imgSrc mempty mempty
       _ ->
         linkToInlinesF src =<< title'
 

src/Text/Pandoc/Readers/Org/Meta.hs

@@ -75,9 +75,9 @@ declarationLine :: PandocMonad m => OrgParser m ()
 declarationLine = try $ do
   key   <- map toLower <$> metaKey
   (key', value) <- metaValue key
-  when (key' /= "results") $
-    updateState $ \st ->
-      st { orgStateMeta = B.setMeta key' <$> value <*> orgStateMeta st }
+  let addMetaValue st =
+        st { orgStateMeta = B.setMeta key' <$> value <*> orgStateMeta st }
+  when (key' /= "results") $ updateState addMetaValue
 
 metaKey :: Monad m => OrgParser m String
 metaKey = map toLower <$> many1 (noneOf ": \n\r")
@@ -236,8 +236,8 @@ macroDefinition = try $ do
   expansionPart = try $ many (notFollowedBy placeholder *> noneOf "\n\r")
 
   alternate :: [a] -> [a] -> [a]
-  alternate [] ys = ys
-  alternate xs [] = xs
+  alternate []     ys     = ys
+  alternate xs     []     = xs
   alternate (x:xs) (y:ys) = x : y : alternate xs ys
 
   reorder :: [Int] -> [String] -> [String]

src/Text/Pandoc/Readers/Org/ParserState.hs

@@ -1,5 +1,5 @@
-{-# LANGUAGE FlexibleInstances          #-}
-{-# LANGUAGE MultiParamTypeClasses      #-}
+{-# LANGUAGE FlexibleInstances     #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
 {-
 Copyright (C) 2014-2017 Albert Krewinkel <tarleb+pandoc@moltkeplatz.de>
 
@@ -60,15 +60,14 @@ import qualified Data.Set as Set
 
 import Text.Pandoc.Builder (Blocks, Inlines)
 import Text.Pandoc.Definition (Meta (..), nullMeta)
-import Text.Pandoc.Options (ReaderOptions (..))
 import Text.Pandoc.Logging
-import Text.Pandoc.Parsing (HasHeaderMap (..), HasIdentifierList (..),
-                            HasLogMessages (..),
-                            HasLastStrPosition (..), HasQuoteContext (..),
-                            HasReaderOptions (..), HasIncludeFiles (..),
-                            ParserContext (..),
-                            QuoteContext (..), SourcePos, Future,
-                            askF, asksF, returnF, runF, trimInlinesF)
+import Text.Pandoc.Options (ReaderOptions (..))
+import Text.Pandoc.Parsing (Future, HasHeaderMap (..), HasIdentifierList (..),
+                            HasIncludeFiles (..), HasLastStrPosition (..),
+                            HasLogMessages (..), HasQuoteContext (..),
+                            HasReaderOptions (..), ParserContext (..),
+                            QuoteContext (..), SourcePos, askF, asksF, returnF,
+                            runF, trimInlinesF)
 
 -- | This is used to delay evaluation until all relevant information has been
 -- parsed and made available in the parser state.

src/Text/Pandoc/Writers/Org.hs

@@ -34,7 +34,7 @@ Conversion of 'Pandoc' documents to Emacs Org-Mode.
 
 Org-Mode:  <http://orgmode.org>
 -}
-module Text.Pandoc.Writers.Org ( writeOrg) where
+module Text.Pandoc.Writers.Org (writeOrg) where
 import Control.Monad.State
 import Data.Char (isAlphaNum, toLower)
 import Data.List (intersect, intersperse, isPrefixOf, partition, transpose)
@@ -77,9 +77,9 @@ pandocToOrg (Pandoc meta blocks) = do
   body <- blockListToOrg blocks
   notes <- gets (reverse . stNotes) >>= notesToOrg
   hasMath <- gets stHasMath
-  let main = render colwidth $ foldl ($+$) empty $ [body, notes]
+  let main = render colwidth . foldl ($+$) empty $ [body, notes]
   let context = defField "body" main
-              $ defField "math" hasMath
+              . defField "math" hasMath
               $ metadata
   case writerTemplate opts of
        Nothing  -> return main
@@ -88,8 +88,7 @@ pandocToOrg (Pandoc meta blocks) = do
 -- | Return Org representation of notes.
 notesToOrg :: PandocMonad m => [[Block]] -> Org m Doc
 notesToOrg notes =
-  mapM (\(num, note) -> noteToOrg num note) (zip [1..] notes) >>=
-  return . vsep
+  vsep <$> zipWithM noteToOrg [1..] notes
 
 -- | Return Org representation of a note.
 noteToOrg :: PandocMonad m => Int -> [Block] -> Org m Doc
@@ -221,16 +220,16 @@ blockToOrg (Table caption' _ _ headers rows) =  do
   -- FIXME: Org doesn't allow blocks with height more than 1.
   let hpipeBlocks blocks = hcat [beg, middle, end]
         where h      = maximum (1 : map height blocks)
-              sep'   = lblock 3 $ vcat (map text $ replicate h " | ")
-              beg    = lblock 2 $ vcat (map text $ replicate h "| ")
-              end    = lblock 2 $ vcat (map text $ replicate h " |")
+              sep'   = lblock 3 $ vcat (replicate h (text " | "))
+              beg    = lblock 2 $ vcat (replicate h (text "| "))
+              end    = lblock 2 $ vcat (replicate h (text " |"))
               middle = hcat $ intersperse sep' blocks
   let makeRow = hpipeBlocks . zipWith lblock widthsInChars
   let head' = makeRow headers'
   rows' <- mapM (\row -> do cols <- mapM blockListToOrg row
                             return $ makeRow cols) rows
   let border ch = char '|' <> char ch <>
-                  (hcat $ intersperse (char ch <> char '+' <> char ch) $
+                  (hcat . intersperse (char ch <> char '+' <> char ch) $
                           map (\l -> text $ replicate l ch) widthsInChars) <>
                   char ch <> char '|'
   let body = vcat rows'
@@ -251,8 +250,7 @@ blockToOrg (OrderedList (start, _, delim) items) = do
   let maxMarkerLength = maximum $ map length markers
   let markers' = map (\m -> let s = maxMarkerLength - length m
                             in  m ++ replicate s ' ') markers
-  contents <- mapM (\(item, num) -> orderedListItemToOrg item num) $
-              zip markers' items
+  contents <- zipWithM orderedListItemToOrg markers' items
   -- ensure that sublists have preceding blank line
   return $ blankline $$ vcat contents $$ blankline
 blockToOrg (DefinitionList items) = do
@@ -279,8 +277,8 @@ definitionListItemToOrg :: PandocMonad m
                         => ([Inline], [[Block]]) -> Org m Doc
 definitionListItemToOrg (label, defs) = do
   label' <- inlineListToOrg label
-  contents <- liftM vcat $ mapM blockListToOrg defs
-  return $ hang 2 "- " $ label' <> " :: " <> (contents <> cr)
+  contents <- vcat <$> mapM blockListToOrg defs
+  return . hang 2 "- " $ label' <> " :: " <> (contents <> cr)
 
 -- | Convert list of key/value pairs to Org :PROPERTIES: drawer.
 propertiesDrawer :: Attr -> Doc
@@ -312,13 +310,13 @@ attrHtml (ident, classes, kvs) =
 blockListToOrg :: PandocMonad m
                => [Block]       -- ^ List of block elements
                -> Org m Doc
-blockListToOrg blocks = mapM blockToOrg blocks >>= return . vcat
+blockListToOrg blocks = vcat <$> mapM blockToOrg blocks
 
 -- | Convert list of Pandoc inline elements to Org.
 inlineListToOrg :: PandocMonad m
                 => [Inline]
                 -> Org m Doc
-inlineListToOrg lst = mapM inlineToOrg lst >>= return . hcat
+inlineListToOrg lst = hcat <$> mapM inlineToOrg lst
 
 -- | Convert Pandoc inline element to Org.
 inlineToOrg :: PandocMonad m => Inline -> Org m Doc
@@ -350,7 +348,7 @@ inlineToOrg (Quoted DoubleQuote lst) = do
   return $ "\"" <> contents <> "\""
 inlineToOrg (Cite _  lst) = inlineListToOrg lst
 inlineToOrg (Code _ str) = return $ "=" <> text str <> "="
-inlineToOrg (Str str) = return $ text $ escapeString str
+inlineToOrg (Str str) = return . text $ escapeString str
 inlineToOrg (Math t str) = do
   modify $ \st -> st{ stHasMath = True }
   return $ if t == InlineMath