Fix minor glitches in the visitors.py docstrings (#6522)

* Fix docstring typo

* Capitalize first sentence word

* Properly markup class name

This is just for consistency with nearby references: the HasCacheKey class has no docstring so
it does not appear in the documentation, moreover it's in the traversals module, so Sphinx
cannot render it as a link anyway.

diff --git a/lib/sqlalchemy/sql/visitors.py b/lib/sqlalchemy/sql/visitors.py
index 793e7fc5c6f5a39a1fb0909ab5a3e5ce33f87ab8..93ee8eb1c175df94084d3141cb23596f0dc87122 100644 (file)
--- a/lib/sqlalchemy/sql/visitors.py
+++ b/lib/sqlalchemy/sql/visitors.py
@@ -169,7 +169,7 @@ class InternalTraversal(util.with_metaclass(_InternalTraversalType, object)):
     various visit methods of the class.   The other is that the symbols
     themselves of :class:`.InternalTraversal` are used within
     the ``_traverse_internals`` collection.   Such as, the :class:`.Case`
-    object defines ``_travserse_internals`` as ::
+    object defines ``_traverse_internals`` as ::
 
         _traverse_internals = [
             ("value", InternalTraversal.dp_clauseelement),
@@ -422,12 +422,12 @@ class InternalTraversal(util.with_metaclass(_InternalTraversalType, object)):
     """
 
     dp_propagate_attrs = symbol("PA")
-    """Visit the propagate attrs dict.   this hardcodes to the particular
+    """Visit the propagate attrs dict.  This hardcodes to the particular
     elements we care about right now."""
 
 
 class ExtendedInternalTraversal(InternalTraversal):
-    """defines additional symbols that are useful in caching applications.
+    """Defines additional symbols that are useful in caching applications.
 
     Traversals for :class:`_expression.ClauseElement` objects only need to use
     those symbols present in :class:`.InternalTraversal`.  However, for
@@ -445,8 +445,8 @@ class ExtendedInternalTraversal(InternalTraversal):
     """
 
     dp_inspectable = symbol("IS")
-    """Visit an inspectable object where the return value is a HasCacheKey`
-    object."""
+    """Visit an inspectable object where the return value is a
+    :class:`.HasCacheKey` object."""
 
     dp_multi = symbol("M")
     """Visit an object that may be a :class:`.HasCacheKey` or may be a