Switch from pretty-simple to pretty-show for native output.

Update tests.

Reason:  it turns out that the native output generated by
pretty-simple isn't always readable by the native reader.
According to https://github.com/cdepillabout/pretty-simple/issues/99
it is not a design goal of the library that the rendered values
be readable using 'read'.  This makes it unsuitable for our
purposes.

pretty-show is a bit slower and it uses 4-space indents
(non-configurable), but it doesn't have this serious drawback.

1 files changed, 8 insertions, 12 deletions

diff --git a/src/Text/Pandoc/Writers/Native.hs b/src/Text/Pandoc/Writers/Native.hs
index 67af39a31..264b9c498 100644
--- a/src/Text/Pandoc/Writers/Native.hs
+++ b/src/Text/Pandoc/Writers/Native.hs
@@ -13,23 +13,19 @@ Conversion of a 'Pandoc' document to a string representation.
 module Text.Pandoc.Writers.Native ( writeNative )
 where
 import Data.Text (Text)
-import qualified Data.Text.Lazy as TL
+import qualified Data.Text as T
 import Text.Pandoc.Class.PandocMonad (PandocMonad)
 import Text.Pandoc.Definition
 import Text.Pandoc.Options (WriterOptions (..))
-import Text.Pretty.Simple (pShowOpt, defaultOutputOptionsNoColor,
-                           OutputOptions(..), StringOutputStyle(..))
+import Text.Show.Pretty (ppDoc)
+import Text.PrettyPrint (renderStyle, Style(..), style, char)
 
 -- | Prettyprint Pandoc document.
 writeNative :: PandocMonad m => WriterOptions -> Pandoc -> m Text
 writeNative opts (Pandoc meta blocks) = do
-  let popts = defaultOutputOptionsNoColor{
-               outputOptionsIndentAmount = 2,
-               outputOptionsPageWidth = writerColumns opts,
-               outputOptionsCompact = True,
-               outputOptionsCompactParens = False,
-               outputOptionsStringStyle = Literal }
-  return $
+  let style' = style{ lineLength = writerColumns opts,
+                      ribbonsPerLine = 1.2 }
+  return $ T.pack $ renderStyle style' $
     case writerTemplate opts of
-      Just _  -> TL.toStrict $ pShowOpt popts (Pandoc meta blocks) <> "\n"
-      Nothing -> TL.toStrict $ pShowOpt popts blocks
+      Just _  -> ppDoc (Pandoc meta blocks) <> char '\n'
+      Nothing -> ppDoc blocks