parse RST class directives

The class directive accepts one or more class names, and creates a Div
value with those classes.  If the directive has an indented body, the
body is parsed as the children of the Div.  If not, the first block
folowing the directive is made a child of the Div.

This differs from the behavior of rst2xml, which does not create a Div
element.  Instead, the specified classes are applied to each child of
the directive.  However, most Pandoc Block constructors to not take an
Attr argument, so we can't duplicate this behavior.

2 files changed, 14 insertions, 2 deletions

diff --git a/src/Text/Pandoc/Readers/RST.hs b/src/Text/Pandoc/Readers/RST.hs
index dbbfe5191..732956981 100644
--- a/src/Text/Pandoc/Readers/RST.hs
+++ b/src/Text/Pandoc/Readers/RST.hs
@@ -47,7 +47,7 @@ import Text.Pandoc.Builder (Inlines, Blocks, trimInlines, (<>))
 import qualified Text.Pandoc.Builder as B
 import Data.Monoid (mconcat, mempty)
 import Data.Sequence (viewr, ViewR(..))
-import Data.Char (toLower, isHexDigit)
+import Data.Char (toLower, isHexDigit, isSpace)
 
 -- | Parse reStructuredText string and return Pandoc document.
 readRST :: ReaderOptions -- ^ Reader options
@@ -521,7 +521,6 @@ directive = try $ do
 -- TODO: line-block, parsed-literal, table, csv-table, list-table
 -- date
 -- include
--- class
 -- title
 directive' :: RSTParser Blocks
 directive' = do
@@ -602,6 +601,13 @@ directive' = do
                           Just t  -> B.link (escapeURI $ trim t) ""
                                      $ B.image src "" alt
                           Nothing -> B.image src "" alt
+        "class" -> do
+            let attrs = ("", (splitBy isSpace $ trim top), map (\(k,v) -> (k, trimr v)) fields)
+            --  directive content or the first immediately following element
+            children <- case body of
+                "" -> block
+                _ -> parseFromString parseBlocks  body'
+            return $ B.divWith attrs children
         _     -> return mempty
 
 -- TODO:
diff --git a/tests/Tests/Readers/RST.hs b/tests/Tests/Readers/RST.hs
index 4b0abdf72..c97dcb149 100644
--- a/tests/Tests/Readers/RST.hs
+++ b/tests/Tests/Readers/RST.hs
@@ -83,4 +83,10 @@ tests = [ "line block with blank line" =:
             =?> codeBlock "> quoted\n> block" <> para "Ordinary paragraph"
           , "quoted literal block using | (not  a line block)" =: "::\n\n| quoted\n| block\n\nOrdinary paragraph"
             =?> codeBlock "| quoted\n| block" <> para "Ordinary paragraph"
+            , "class directive with single paragraph" =: ".. class:: special\n\nThis is a \"special\" paragraph."
+              =?> divWith ("", ["special"], []) (para "This is a \"special\" paragraph.")
+            , "class directive with two paragraphs" =: ".. class:: exceptional remarkable\n\n    First paragraph.\n\n    Second paragraph."
+              =?> divWith ("", ["exceptional", "remarkable"], []) (para "First paragraph." <> para "Second paragraph.")
+            , "class directive around literal block" =: ".. class:: classy\n\n::\n\n    a\n    b"
+              =?> divWith ("", ["classy"], []) (codeBlock "a\nb")
         ]