only walk once

langfilter/Main.hs

@@ -25,14 +25,10 @@ main = toJSONFilter filter where
     defColor <- getDefColor m
     let ?lang = lang
     let ?defColor = defColor
-    pure $
-      walk fixFigureClass $
-      walk makeEbnf $
-      walk makeQuotes $
-      walk (concatMap makeBlocks) $
-      walk inlineLetterList $
-      walk spans $
-      walk (concat . map glosses) p
+    let f = map (walk spans . fixFigureClass . makeEbnf .
+                 makeQuotes . letterList) .
+            concatMap (makeBlocks <=< glosses)
+    pure $ walk f p
 
 getDefColor :: Map Text MetaValue -> IO Text
 getDefColor m = do
@@ -86,11 +82,10 @@ makeQuotes para@(Para b) = fromMaybe para $ do
     checkEnd _                    = empty
 makeQuotes other = other
 
-
-inlineLetterList :: Block -> Block
-inlineLetterList (Div a@(_, cs, _) blks)
+letterList :: Block -> Block
+letterList (Div a@(_, cs, _) blks)
   | "letter-list" `elem` cs = Div a (walk go blks)
  where
   go (Para xs) = Plain xs
   go b         = b
-inlineLetterList b = b
+letterList b = b