1 files changed, 35 insertions, 0 deletions
diff --git a/pystache/common.py b/pystache/common.py
index c1fd7a1..fb266dd 100644
--- a/pystache/common.py
+++ b/pystache/common.py
@@ -5,6 +5,33 @@ Exposes functionality needed throughout the project.
 
 """
 
+from sys import version_info
+
+def _get_string_types():
+    # TODO: come up with a better solution for this.  One of the issues here
+    #   is that in Python 3 there is no common base class for unicode strings
+    #   and byte strings, and 2to3 seems to convert all of "str", "unicode",
+    #   and "basestring" to Python 3's "str".
+    if version_info < (3, ):
+         return basestring
+    # The latter evaluates to "bytes" in Python 3 -- even after conversion by 2to3.
+    return (unicode, type(u"a".encode('utf-8')))
+
+
+_STRING_TYPES = _get_string_types()
+
+
+def is_string(obj):
+    """
+    Return whether the given object is a byte string or unicode string.
+
+    This function is provided for compatibility with both Python 2 and 3
+    when using 2to3.
+
+    """
+    return isinstance(obj, _STRING_TYPES)
+
+
 # This function was designed to be portable across Python versions -- both
 # with older versions and with Python 3 after applying 2to3.
 def read(path):
@@ -26,6 +53,14 @@ def read(path):
         f.close()
 
 
+class MissingTags(object):
+
+    """Contains the valid values for Renderer.missing_tags."""
+
+    ignore = 'ignore'
+    strict = 'strict'
+
+
 class PystacheError(Exception):
     """Base class for Pystache exceptions."""
     pass