feat: easily separate renderables by blank lines

3 files changed, 26 insertions, 17 deletions

diff --git a/app/Issue/Render.hs b/app/Issue/Render.hs
index 39249ae..c8a913b 100644
--- a/app/Issue/Render.hs
+++ b/app/Issue/Render.hs
@@ -18,25 +18,15 @@ import Data.Time.Clock (UTCTime (utctDay))
 import Git (Author (..), Commit (..))
 import Issue (Issue (..))
 import Issue.Provenance (Provenance (..))
-import Render ((<<<))
+import Render ((<<<), (===))
 import Render qualified as P
 
--- TODO Easily separate renderables by newlines
---
--- For convenience, the (<<<) combinator adds spaces between renderable entities, **if** those renderables are non-empty.
---
--- We should similarly allow for a combinator that similarly adds empty lines between renderable entities.
---
--- @topic rendering
 instance P.Render (P.Detailed Issue) where
   render (P.Detailed issue) =
     IssueTitle issue
-      <<< P.hardline @P.AnsiStyle
-      <<< IssueDescription issue
-      <<< P.hardline @P.AnsiStyle
-      <<< IssueTags issue
-      <<< P.hardline @P.AnsiStyle
-      <<< IssueComments issue
+      === IssueDescription issue
+      === IssueTags issue
+      === IssueComments issue
 
 instance P.Render Issue where
   render = P.render . P.Detailed
diff --git a/app/Main.hs b/app/Main.hs
index da4ea6a..46f6e77 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -573,10 +573,10 @@ main = do
         map (if detailed then (P.render . P.Detailed) else (P.render . P.Summarized)) issues
     Options {colorize, noPager, width, command = Log {patch}} -> do
       es <- reverse . (.issueEvents) <$> getHistory
-      putDoc colorize noPager width . P.vsep $
+      putDoc colorize noPager width $
         if patch
-          then map (P.render . P.Detailed) es
-          else map (P.render . P.Summarized) es
+          then P.vsep . intersperse P.emptyDoc $ map (P.render . P.Detailed) es
+          else P.vsep $ map (P.render . P.Summarized) es
     Options {colorize, noPager, width, command = Show {id, edit}} -> do
       issues <- (.issues) <$> getHistory
       issue <-
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