Update docs about sphinx.parsers.Parser class

1 files changed, 16 insertions, 1 deletions

diff --git a/sphinx/parsers.py b/sphinx/parsers.py
index b7ca89aa5..926de9f1c 100644
--- a/sphinx/parsers.py
+++ b/sphinx/parsers.py
@@ -14,7 +14,22 @@ import docutils.parsers
 
 class Parser(docutils.parsers.Parser):
     """
-    A base class of parsers.
+    A base class of source parsers.  The additonal parsers should inherits this class instead
+    of ``docutils.parsers.Parser``.  Compared with ``docutils.parsers.Parser``, this class
+    improves accessibility to Sphinx APIs.
+
+    The subclasses can access following objects and functions:
+
+    self.app
+        The application object (:class:`sphinx.application.Sphinx`)
+    self.config
+        The config object (:class:`sphinx.config.Config`)
+    self.env
+        The environment object (:class:`sphinx.environment.BuildEnvironment`)
+    self.warn()
+        Emit a warning. (Same as :meth:`sphinx.application.Sphinx.warn()`)
+    self.info()
+        Emit a informational message. (Same as :meth:`sphinx.application.Sphinx.info()`)
     """
 
     def set_application(self, app):