simplified creation of attributes;

there is some redundancy now (the dictionary appears twice), and the backrefs
attribute is set not only for BackLinkable nodes but for all Elements,
but for simplicity that is OK, IMO;
and after all, it provides quite a significant speedup

git-svn-id: http://svn.code.sf.net/p/docutils/code/trunk/docutils@3136 929543f6-e4f2-0310-98a6-ba3bd3dd1d04

2 files changed, 6 insertions, 10 deletions

diff --git a/HISTORY.txt b/HISTORY.txt
index a89dac67c..b7c447292 100644
--- a/HISTORY.txt
+++ b/HISTORY.txt
@@ -38,8 +38,7 @@ Changes Since 0.3.7
     TextElement (it's an empty element, and cannot contain text).
   - Added ``attr_defaults`` dictionary for default attribute values.
   - Added empty list as default value for the following attributes:
-    ``ids``, ``names``, ``dupnames``, ``classes`` for Element nodes,
-    and additionally ``backrefs`` for BackLinkable nodes.
+    ``ids``, ``names``, ``dupnames``, ``classes``, and ``backrefs``.
 
 * docutils/languages/nl.py: Added to project; Dutch mappings by
   Martijn Pieters.
diff --git a/docutils/nodes.py b/docutils/nodes.py
index 021c2dbf0..b6c34e359 100644
--- a/docutils/nodes.py
+++ b/docutils/nodes.py
@@ -27,7 +27,6 @@ import sys
 import os
 import re
 import xml.dom.minidom
-from copy import deepcopy
 from types import IntType, SliceType, StringType, UnicodeType, \
      TupleType, ListType
 from UserString import UserString
@@ -327,9 +326,9 @@ class Element(Node):
     This is equivalent to ``element.extend([node1, node2])``.
     """
 
-    attr_defaults = {'ids': [], 'classes': [], 'names': [], 'dupnames': []}
-    """Default attributes.  ``attributes`` is initialized with a copy
-    of ``attr_defaults``."""
+    attr_defaults = {'ids': [], 'classes': [], 'names': [],
+                     'dupnames': [], 'backrefs': []}
+    """Default attributes."""
 
     tagname = None
     """The element generic identifier. If None, it is set as an instance
@@ -347,7 +346,8 @@ class Element(Node):
 
         self.extend(children)           # maintain parent info
 
-        self.attributes = deepcopy(self.attr_defaults)
+        self.attributes = {'ids': [], 'classes': [], 'names': [],
+                           'dupnames': [], 'backrefs': []}
         """Dictionary of attribute {name: value}."""
 
         for att, value in attributes.items():
@@ -664,9 +664,6 @@ class Resolvable:
 
 class BackLinkable:
 
-    attr_defaults = Element.attr_defaults.copy()
-    attr_defaults['backrefs'] = []
-
     def add_backref(self, refid):
         self['backrefs'].append(refid)