merge 2to3 improvments

1 files changed, 13 insertions, 0 deletions

diff --git a/Lib/lib2to3/pgen2/grammar.py b/Lib/lib2to3/pgen2/grammar.py
index b7f867f..26caeb4 100644
--- a/Lib/lib2to3/pgen2/grammar.py
+++ b/Lib/lib2to3/pgen2/grammar.py
@@ -97,6 +97,19 @@ class Grammar(object):
         f.close()
         self.__dict__.update(d)
 
+    def copy(self):
+        """
+        Copy the grammar.
+        """
+        new = self.__class__()
+        for dict_attr in ("symbol2number", "number2symbol", "dfas", "keywords",
+                          "tokens", "symbol2label"):
+            setattr(new, dict_attr, getattr(self, dict_attr).copy())
+        new.labels = self.labels[:]
+        new.states = self.states[:]
+        new.start = self.start
+        return new
+
     def report(self):
         """Dump the grammar tables to standard output, for debugging."""
         from pprint import pprint