feat: easily separate renderables by blank lines

1 files changed, 19 insertions, 0 deletions

diff --git a/app/Render.hs b/app/Render.hs
index f63a3bc..964581f 100644
--- a/app/Render.hs
+++ b/app/Render.hs
@@ -10,6 +10,7 @@ module Render
     -- * Render
     Render (..),
     (<<<),
+    (===),
     styled,
 
     -- * Reporting styles
@@ -72,6 +73,24 @@ instance Render Day where
     startsWithNL = ("\n" `isPrefixOf`) . show . render
     endsWithNL = ("\n" `isSuffixOf`) . show . render
 
+(===) :: (Render a, Render b) => a -> b -> Doc AnsiStyle
+(===) a' b' =
+  case (nonEmpty a', nonEmpty b') of
+    (Nothing, Nothing) -> emptyDoc
+    (Just a, Nothing) -> a
+    (Nothing, Just b) -> b
+    (Just a, Just b) ->
+      if
+          | endsWithNL a && startsWithNL b -> a <> b
+          | endsWithNL a || startsWithNL b -> a <> hardline <> b
+          | otherwise -> a <> hardline <> hardline <> b
+  where
+    nonEmpty x' =
+      let x = render x'
+       in if not (null (show x)) then Just (render x) else Nothing
+    startsWithNL = ("\n" `isPrefixOf`) . show . render
+    endsWithNL = ("\n" `isSuffixOf`) . show . render
+
 -- | `styled` allows to annotate a document with multiple annotations. It obsoletes prettyprinter's `annotate`.
 styled :: [AnsiStyle] -> Doc AnsiStyle -> Doc AnsiStyle
 styled [] doc = doc