further reduce newlines for compact output (#84)

added a doctest reflecting the more compact [(a,b)] output

src/Text/Pretty/Simple.hs

@@ -680,6 +680,15 @@ layoutStringAnsi opts = fmap convertStyle . layoutString opts
 --         , B
 --             ( B ( B A ) ) ] )
 --
+-- >>> pPrintOpt CheckColorTty defaultOutputOptionsDarkBg {outputOptionsCompact = True} $ [("id", 123), ("state", 1), ("pass", 1), ("tested", 100), ("time", 12345)]
+-- [
+--     ( "id", 123 ),
+--     ( "state", 1 ),
+--     ( "pass", 1 ),
+--     ( "tested", 100 ),
+--     ( "time", 12345 )
+-- ]
+--
 -- __Initial indent__
 --
 -- >>> pPrintOpt CheckColorTty defaultOutputOptionsDarkBg {outputOptionsInitialIndent = 3} $ B ( B ( B ( B A ) ) )

src/Text/Pretty/Simple/Internal/Printer.hs

@@ -255,7 +255,10 @@ prettyExpr opts = (if outputOptionsCompact opts then group else id) . \case
             spaceIfNeeded = \case
               Other (' ' : _) : _ -> mempty
               _ -> space
-    lineAndCommaSep x y = x <> line' <> annotate Comma "," <> y
+    lineAndCommaSep x y =
+      if outputOptionsCompact opts
+      then x <> annotate Comma "," <> y
+      else x <> line' <> annotate Comma "," <> y
 
 -- | Determine whether this expression should be displayed on a single line.
 isSimple :: Expr -> Bool