[Zope-Checkins] CVS: Zope2 - Eval.py:1.1.2.8

[shane@digicool.com]

Update of /cvs-repository/Zope2/lib/python/RestrictedPython
In directory korak:/tmp/cvs-serv19956

Modified Files:
      Tag: RestrictedPythonBranch
	Eval.py 
Log Message:
Added comments and used "None" for the default builtins, which is rumored
to be safer... :-/



--- Updated File Eval.py in package Zope2 --
--- Eval.py	2001/04/26 22:20:26	1.1.2.7
+++ Eval.py	2001/04/27 15:19:41	1.1.2.8
@@ -102,7 +102,7 @@
 class RestrictionCapableEval:
     """A base class for restricted code.
     """
-    globals = {'__builtins__': {}}
+    globals = {'__builtins__': None}
     rcode = None  # restricted
     ucode = None  # unrestricted
     used = None
@@ -113,8 +113,6 @@
         where:
 
           expr -- a string containing the expression to be evaluated.
-
-          globals -- A global namespace.
         """
         expr = strip(expr)
         self.__name__ = expr
@@ -145,8 +143,11 @@
 
     def prepUnrestrictedCode(self):
         if self.ucode is None:
+            # Use the standard compiler.
             co = compile(self.expr, '<string>', 'eval')
             if self.used is None:
+                # Examine the code object, discovering which names
+                # the expression needs.
                 names=list(co.co_names)
                 used={}
                 i=0
@@ -166,6 +167,8 @@
             self.ucode=co
 
     def eval(self, mapping):
+        # This default implementation is probably not very useful. :-(
+        # This is meant to be overridden.
         self.prepRestrictedCode()
         code = self.rcode
         d = {'_read_': default_read_guard}