Org reader: support new syntax for export blocks

Org-mode version 9 usees a new syntax for export blocks.  Instead of
`#+BEGIN_<FORMAT>`, where `<FORMAT>` is the format of the block's
content, the new format uses `#+BEGIN_export <FORMAT>` instead.  Both
types are supported.

1 files changed, 9 insertions, 0 deletions

diff --git a/src/Text/Pandoc/Readers/Org/Blocks.hs b/src/Text/Pandoc/Readers/Org/Blocks.hs
index dba36fa4d..36645a356 100644
--- a/src/Text/Pandoc/Readers/Org/Blocks.hs
+++ b/src/Text/Pandoc/Readers/Org/Blocks.hs
@@ -168,6 +168,7 @@ orgBlock = try $ do
   blkType <- blockHeaderStart
   ($ blkType) $
     case blkType of
+      "export"  -> exportBlock
       "comment" -> rawBlockLines (const mempty)
       "html"    -> rawBlockLines (return . (B.rawBlock blkType))
       "latex"   -> rawBlockLines (return . (B.rawBlock blkType))
@@ -239,6 +240,14 @@ rawBlockContent blockType = try $ do
 ignHeaders :: OrgParser ()
 ignHeaders = (() <$ newline) <|> (() <$ anyLine)
 
+-- | Read a block containing code intended for export in specific backends
+-- only.
+exportBlock :: String -> OrgParser (F Blocks)
+exportBlock blockType = try $ do
+  exportType <- skipSpaces *> orgArgWord <* ignHeaders
+  contents   <- rawBlockContent blockType
+  returnF (B.rawBlock (map toLower exportType) contents)
+
 verseBlock :: String -> OrgParser (F Blocks)
 verseBlock blockType = try $ do
   ignHeaders