fix: fix spacing between markdown nodes

1 files changed, 15 insertions, 12 deletions

diff --git a/app/Render.hs b/app/Render.hs
index 6cb0373..f4293c2 100644
--- a/app/Render.hs
+++ b/app/Render.hs
@@ -129,15 +129,6 @@ instance Render Markdown where
 instance Render [D.Node] where
   render = render . D.Node Nothing D.DOCUMENT
 
--- TODO Fix spacing between markdown nodes
---
--- The following code suffers from the problem that inline code such as `foo` is not separated correctly when surrounded by non-whitespace characters, ie. `foo`, or `foo`s.
---
--- The reason for that is that we generally trim words within `TEXT` nodes, and then add the spaces back.
---
--- Thus, we should not trim words. But we should still replace whitespace by `P.softline`s (ie. `P.fillSep`) for automatic paragraph wrapping.
---
--- @topic markdown
 instance Render D.Node where
   render = maybe emptyDoc go . rec
     where
@@ -146,7 +137,7 @@ instance Render D.Node where
 
       go (D.Node _ D.DOCUMENT ns) = vsep (intersperse (pretty ("" :: T.Text)) (map go ns))
       go (D.Node _ D.THEMATIC_BREAK _) = pretty ("***" :: T.Text)
-      go (D.Node _ D.PARAGRAPH ns) = fillSep $ map go ns
+      go (D.Node _ D.PARAGRAPH ns) = hcat $ map go ns
       go (D.Node _ D.BLOCK_QUOTE ns) =
         styled [color Black] . fillSep $
           pretty (">" :: T.Text)
@@ -181,8 +172,20 @@ instance Render D.Node where
         hsep (map ((pretty ("- " :: T.Text)) <>) (map go ns))
       go (D.Node _ D.ITEM ns) = fillSep (map go ns)
       go (D.Node _ (D.TEXT s) _) =
-        fillSep . map (pretty . T.strip) $
-          T.words s
+        hcat
+          . intersperse softline
+          . map pretty
+          . ( \xs ->
+                -- first and last `T.null`-elements must be preserved as it may represents whitespace between sibling `D.Node`s.
+                if length xs >= 2
+                  then
+                    head xs
+                      : filter (not . T.null) (tail . init $ xs)
+                      ++ [last xs]
+                  else xs
+            )
+          . T.split (== ' ')
+          $ s
       go (D.Node _ D.LINEBREAK _) = hardline
       go (D.Node _ (D.HTML_INLINE s) _) =
         styled [color Yellow] $ pretty (T.strip s)