Revert "Markdown writer: Don't include variables in metadata."

This reverts commit 0ec8573347d53e0cba70552a50dba697f39216b6.

2 files changed, 36 insertions, 42 deletions

diff --git a/src/Text/Pandoc/Writers/Markdown.hs b/src/Text/Pandoc/Writers/Markdown.hs
index e464d63b5..d8ac99685 100644
--- a/src/Text/Pandoc/Writers/Markdown.hs
+++ b/src/Text/Pandoc/Writers/Markdown.hs
@@ -46,8 +46,10 @@ import Text.Pandoc.Readers.TeXMath (readTeXMath)
 import Text.HTML.TagSoup (renderTags, parseTags, isTagText, Tag(..))
 import Network.URI (isAbsoluteURI)
 import Data.Default
-import qualified Data.Map as M
-import Control.Applicative ((<$>))
+import Data.Yaml (Value(Object,String,Array,Bool,Number))
+import qualified Data.HashMap.Strict as H
+import qualified Data.Vector as V
+import qualified Data.Text as T
 
 type Notes = [[Block]]
 type Refs = [([Inline], Target)]
@@ -111,34 +113,21 @@ plainTitleBlock tit auths dat =
   (hcat (intersperse (text "; ") auths)) <> cr <>
   dat <> cr
 
-yamlTitleBlock :: WriterOptions -> Meta -> State WriterState Doc
-yamlTitleBlock opts (Meta metamap) = do
-  m <- jsonToYaml opts (MetaMap metamap)
-  return $ "---" $$ m $$ "..."
-
-jsonToYaml :: WriterOptions -> MetaValue -> State WriterState Doc
-jsonToYaml opts (MetaMap metamap) = vcat
-  <$> mapM (\(k,v) -> ((text k <> ":") <>) <$>
-             case v of
-                (MetaList _) -> (cr <>) <$> jsonToYaml opts v
-                (MetaMap _)  -> ((cr <>) . nest 2) <$> jsonToYaml opts v
-                _            -> (space <> ) <$> jsonToYaml opts v)
-           (M.toList metamap)
-jsonToYaml opts (MetaList xs) = vcat
-  <$> mapM (\v -> hang 2 "- " <$> (jsonToYaml opts v)) xs
-jsonToYaml _ (MetaString s)
-  | '\n' `elem` s = return $ hang 2 ("|" <> cr) $ text s
-  | otherwise            = return $ text $ "'" ++ substitute "'" "''" s ++ "'"
-jsonToYaml opts (MetaInlines ils) =
-  inlineListToMarkdown opts ils >>= jsonToYaml opts . MetaString . render' opts
-jsonToYaml opts (MetaBlocks bs) =
-  blockListToMarkdown opts bs >>= jsonToYaml opts . MetaString . render' opts
-
-render' :: WriterOptions -> Doc -> String
-render' opts = render colwidth
-  where colwidth = if writerWrapText opts
-                      then Just $ writerColumns opts
-                      else Nothing
+yamlTitleBlock :: Value -> Doc
+yamlTitleBlock v = "---" $$ (jsonToYaml v) $$ "..."
+
+jsonToYaml :: Value -> Doc
+jsonToYaml (Object hashmap) =
+  vcat (map (\(k,v) ->
+    text (T.unpack k) <> ":" <> space <> jsonToYaml v) $ H.toList hashmap)
+jsonToYaml (Array vec) =
+  cr <> vcat (map (\v -> hang 2 "- " (jsonToYaml v)) $ V.toList vec)
+jsonToYaml (String s)
+  | "\n" `T.isInfixOf` s = hang 2 ("|" <> cr) $ text $ T.unpack s
+  | otherwise            = text $ "'" ++ substitute "'" "''" (T.unpack s) ++ "'"
+jsonToYaml (Bool b) = text $ show b
+jsonToYaml (Number n) = text $ show n
+jsonToYaml _ = empty
 
 -- | Return markdown representation of document.
 pandocToMarkdown :: WriterOptions -> Pandoc -> State WriterState String
@@ -146,22 +135,25 @@ pandocToMarkdown opts (Pandoc meta blocks) = do
   title' <- inlineListToMarkdown opts $ docTitle meta
   authors' <- mapM (inlineListToMarkdown opts) $ docAuthors meta
   date' <- inlineListToMarkdown opts $ docDate meta
+  let colwidth = if writerWrapText opts
+                    then Just $ writerColumns opts
+                    else Nothing
   metadata <- metaToJSON
-              (fmap (render' opts) . blockListToMarkdown opts)
-              (fmap (render' opts) . inlineListToMarkdown opts)
+              (fmap (render colwidth) . blockListToMarkdown opts)
+              (fmap (render colwidth) . inlineListToMarkdown opts)
               (writerVariables opts)
               meta
   isPlain <- gets stPlain
-  titleblock <- case True of
+  let titleblock = case True of
                         _ | isPlain ->
-                              return $ plainTitleBlock title' authors' date'
+                              plainTitleBlock title' authors' date'
                           | isEnabled Ext_yaml_title_block opts ->
-                              yamlTitleBlock opts meta
+                              yamlTitleBlock metadata
                           | isEnabled Ext_pandoc_title_block opts ->
-                              return $ pandocTitleBlock title' authors' date'
+                              pandocTitleBlock title' authors' date'
                           | isEnabled Ext_mmd_title_block opts ->
-                              return $ mmdTitleBlock title' authors' date'
-                          | otherwise -> return empty
+                              mmdTitleBlock title' authors' date'
+                          | otherwise -> empty
   let headerBlocks = filter isHeaderBlock blocks
   let toc = if writerTableOfContents opts
                then tableOfContents opts headerBlocks
@@ -171,14 +163,16 @@ pandocToMarkdown opts (Pandoc meta blocks) = do
   notes' <- notesToMarkdown opts (reverse $ stNotes st)
   st' <- get  -- note that the notes may contain refs
   refs' <- refsToMarkdown opts (reverse $ stRefs st')
-  let main = render' opts $ body <>
+  let render' :: Doc -> String
+      render' = render colwidth
+  let main = render' $ body <>
                (if isEmpty notes' then empty else blankline <> notes') <>
                (if isEmpty refs' then empty else blankline <> refs')
-  let context  = defField "toc" (render' opts toc)
+  let context  = defField "toc" (render' toc)
                $ defField "body" main
                $ (if not (null (docTitle meta) && null (docAuthors meta)
                            && null (docDate meta))
-                     then defField "titleblock" (render' opts titleblock)
+                     then defField "titleblock" (render' titleblock)
                      else id)
                $ metadata
   if writerStandalone opts
diff --git a/tests/writer.markdown b/tests/writer.markdown
index 31be784b2..e8aca9954 100644
--- a/tests/writer.markdown
+++ b/tests/writer.markdown
@@ -1,9 +1,9 @@
 ---
+title: 'Pandoc Test Suite'
 author:
 - 'John MacFarlane'
 - 'Anonymous'
 date: 'July 17, 2006'
-title: 'Pandoc Test Suite'
 ...
 
 This is a set of tests for pandoc. Most of them are adapted from John Gruber’s