add local anchors to headers

1 files changed, 16 insertions, 0 deletions

diff --git a/Utils.hs b/Utils.hs
index 4828335..c72e080 100644
--- a/Utils.hs
+++ b/Utils.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE OverloadedStrings #-}
+
 module Utils where
 
 import Control.Monad.IO.Class
@@ -41,6 +43,20 @@ walkURLs f = Text.Pandoc.Walk.walkM go
       pure $ Image a i (u', t)
     go x = pure x
 
+-- | A pandoc walker for adding the local links to the headings (links are
+-- appended and get a given class)
+addHeadingLinks ::
+     T.Text -> Text.Pandoc.Definition.Pandoc -> Text.Pandoc.Definition.Pandoc
+addHeadingLinks cls = Text.Pandoc.Walk.walk go
+  where
+    go h@(Header lvl attr@(id, _, _) inlines) =
+      Header
+        lvl
+        attr
+        (inlines ++
+         [Link ("", [cls], []) [Str "#"] ("#" <> id, "Link to this section")])
+    go x = x
+
 hasUriScheme :: String -> String -> Bool
 hasUriScheme x = all id . zipWith (==) x . (++ ":")