md_tw.py: Add TWBlockLexer.parse_lheading.

* md_tw.py
(TWBlockLexer.parse_lheading): New method.
* tests/test_md_tw.py
(TestTWBlockLexer.test_parse_lheading): New method.
* tests/data/blexer-lheading.md: New file.

1 files changed, 8 insertions, 0 deletions

diff --git a/md_tw.py b/md_tw.py
index 64c9ced..10bd0a8 100644
--- a/md_tw.py
+++ b/md_tw.py
@@ -59,6 +59,14 @@ class TWBlockLexer(mistune.BlockLexer):
             'text': m.group(0),
         })
 
+    def parse_lheading(self, m):
+        """Parse setext heading."""
+        self.tokens.append({
+            'type': 'heading',
+            'level': 1 if m.group(2) == '=' else 2,
+            'text': m.group(0),
+        })
+
 
 class TWInlineLexer(mistune.InlineLexer):
     """Text Wrap Inline level lexer for inline gramars."""