RST reader: support inline anchors.

Closes #9196.

src/Text/Pandoc/Readers/RST.hs

@@ -1394,6 +1394,7 @@ table = gridTable <|> simpleTable False <|> simpleTable True <?> "table"
 inline :: PandocMonad m => RSTParser m Inlines
 inline = choice [ note          -- can start with whitespace, so try before ws
                 , link
+                , inlineAnchor
                 , strong
                 , emph
                 , code
@@ -1721,3 +1722,13 @@ note = try $ do
 
 smart :: PandocMonad m => RSTParser m Inlines
 smart = smartPunctuation inline
+
+inlineAnchor :: PandocMonad m => RSTParser m Inlines
+inlineAnchor = do
+  char '_'
+  name <- quotedReferenceName <|> simpleReferenceName
+  let ident = textToIdentifier mempty name
+  updateState $ \s ->
+    s{ stateKeys = M.insert (toKey name) (("#" <> ident, ""), nullAttr)
+                    (stateKeys s) }
+  pure $ B.spanWith (ident,[],[]) (B.text name)

test/command/9196.md

@@ -0,0 +1,6 @@
+```
+% pandoc -f rst --wrap=none
+Define  _`my target`, then reference `my target`_.
+^D
+<p>Define <span id="my-target">my target</span>, then reference <a href="#my-target">my target</a>.</p>
+```