HTML reader: simplify list attribute handling

This removes the `foldOrElse` function from the internal Text.Pandoc.CSS
module.

2 files changed, 12 insertions, 27 deletions

diff --git a/src/Text/Pandoc/CSS.hs b/src/Text/Pandoc/CSS.hs
index 3f88d2006..80251850b 100644
--- a/src/Text/Pandoc/CSS.hs
+++ b/src/Text/Pandoc/CSS.hs
@@ -11,13 +11,13 @@ Portability : portable
 
 Tools for working with CSS.
 -}
-module Text.Pandoc.CSS ( foldOrElse
-                       , pickStyleAttrProps
+module Text.Pandoc.CSS ( pickStyleAttrProps
                        , pickStylesToKVs
                        )
 where
 
 import qualified Data.Text as T
+import Data.Maybe (mapMaybe, listToMaybe)
 import Text.Pandoc.Shared (trim)
 import Text.Parsec
 import Text.Parsec.Text
@@ -31,12 +31,6 @@ ruleParser = do
 styleAttrParser :: Parser [(T.Text, T.Text)]
 styleAttrParser = many1 ruleParser
 
-orElse :: Eq a => a -> a -> a -> a
-orElse v x y = if v == x then y else x
-
-foldOrElse :: Eq a => a -> [a] -> a
-foldOrElse v xs = foldr (orElse v) v xs
-
 eitherToMaybe :: Either a b -> Maybe b
 eitherToMaybe (Right x) = Just x
 eitherToMaybe _         = Nothing
@@ -54,4 +48,4 @@ pickStylesToKVs props styleAttr =
 pickStyleAttrProps :: [T.Text] -> T.Text -> Maybe T.Text
 pickStyleAttrProps lookupProps styleAttr = do
     styles <- eitherToMaybe $ parse styleAttrParser "" styleAttr
-    foldOrElse Nothing $ map (`lookup` styles) lookupProps
+    listToMaybe $ mapMaybe (`lookup` styles) lookupProps
diff --git a/src/Text/Pandoc/Readers/HTML.hs b/src/Text/Pandoc/Readers/HTML.hs
index e33dface7..95f034521 100644
--- a/src/Text/Pandoc/Readers/HTML.hs
+++ b/src/Text/Pandoc/Readers/HTML.hs
@@ -46,7 +46,7 @@ import Text.HTML.TagSoup.Match
 import Text.Pandoc.Builder (Blocks, Inlines, trimInlines)
 import qualified Text.Pandoc.Builder as B
 import Text.Pandoc.Class.PandocMonad (PandocMonad (..))
-import Text.Pandoc.CSS (foldOrElse, pickStyleAttrProps)
+import Text.Pandoc.CSS (pickStyleAttrProps)
 import qualified Text.Pandoc.UTF8 as UTF8
 import Text.Pandoc.Definition
 import Text.Pandoc.Readers.HTML.Parsing
@@ -290,23 +290,14 @@ pOrderedList :: PandocMonad m => TagParser m Blocks
 pOrderedList = try $ do
   TagOpen _ attribs' <- pSatisfy (matchTagOpen "ol" [])
   let attribs = toStringAttr attribs'
-  let (start, style) = (sta', sty')
-                       where sta = fromMaybe "1" $
-                                   lookup "start" attribs
-                             sta' = fromMaybe 1 $ safeRead sta
-
-                             pickListStyle = pickStyleAttrProps ["list-style-type", "list-style"]
-
-                             typeAttr  = fromMaybe "" $ lookup "type"  attribs
-                             classAttr = fromMaybe "" $ lookup "class" attribs
-                             styleAttr = fromMaybe "" $ lookup "style" attribs
-                             listStyle = fromMaybe "" $ pickListStyle styleAttr
-
-                             sty' = foldOrElse DefaultStyle
-                                      [ parseTypeAttr      typeAttr
-                                      , parseListStyleType classAttr
-                                      , parseListStyleType listStyle
-                                      ]
+  let start = fromMaybe 1 $ lookup "start" attribs >>= safeRead
+  let style = fromMaybe DefaultStyle
+         $  (parseTypeAttr      <$> lookup "type" attribs)
+        <|> (parseListStyleType <$> lookup "class" attribs)
+        <|> (parseListStyleType <$> (lookup "style" attribs >>= pickListStyle))
+        where
+          pickListStyle = pickStyleAttrProps ["list-style-type", "list-style"]
+
   let nonItem = pSatisfy (\t ->
                   not (tagOpen (`elem` ["li","ol","ul","dl"]) (const True) t) &&
                   not (matchTagClose "ol" t))