Removed validate attribute.

Added template dict to override arguments.

lib/python/DocumentTemplate/VSEval.py

 
 """Very Safe Python Expressions
 """
-__rcs_id__='$Id: VSEval.py,v 1.2 1997/10/27 17:40:35 jim Exp $'
+__rcs_id__='$Id: VSEval.py,v 1.3 1997/10/28 21:51:20 jim Exp $'
 
 ############################################################################
 #     Copyright 
@@ -55,7 +55,7 @@ __rcs_id__='$Id: VSEval.py,v 1.2 1997/10/27 17:40:35 jim Exp $'
 #   (540) 371-6909
 #
 ############################################################################ 
-__version__='$Revision: 1.2 $'[11:-2]
+__version__='$Revision: 1.3 $'[11:-2]
 
 from string import join
 import new, sys
@@ -75,7 +75,6 @@ class Eval:
     or to disallow or limit attribute access.
 
     """
-    validate=None
 
     def __init__(self, expr, custom=None, globals={'__builtins__':{}}, **kw):
 	"""Create a 'safe' expression
@@ -101,8 +100,6 @@ class Eval:
 		custom=d
 	else: custom=kw
 
-	if custom.has_key('validate'): self.validate=custom['validate']
-
 	self.expr=expr
 	self.globals=globals
 
@@ -136,8 +133,12 @@ class Eval:
 		    raise TypeError, ("illegal operation, %s, in %s"
 				      % (name, expr))
 
+
+		# custop(op1,op2,env)   
 		self._const(out, custop, consts)
-		self._bfunc(out)
+		out.append(ROT_THREE)
+		envpos=self._push_env(out, envpos, names)
+		out[len(out):]=[CALL_FUNCTION, 3, 0]
 		i=i+1
 
 	    elif unops.has_key(c) and custom.has_key(unops[c]):
@@ -147,9 +148,11 @@ class Eval:
 		    raise TypeError, ("illegal operation, %s, in %s"
 				      % (name, expr))
 		
-		# Old code, simple getattr insertion
+		# custop(op,env)   
 		self._const(out, custop, consts)
-		self._ufunc(out)
+		out.append(ROT_TWO)
+		envpos=self._push_env(out, envpos, names)
+		out[len(out):]=[CALL_FUNCTION, 2, 0]
 		i=i+1
 
 	    elif c==LOAD_ATTR and custom.has_key('__getattr__'):
@@ -161,42 +164,16 @@ class Eval:
 			Attribute access is not allowed.
 			"""
 			% expr)
-
-		# Old code that uses a simple getattr method:
-		#self._const(out, names[ord(code[i+1])+256*ord(code[i+2])],
-		#	    consts)
-		#self._const(out, custop, consts)
-		#self._bfunc(out)
-
-		# New code that assumes a three-parameter method that
-		# take's three arguments, an environment object, an 
-		# instance, and a name
-
-		# push name of special environment variable, '_env':
-		if envpos < 0:
-		    envpos=len(names)
-		    names.append('_env')
-		out.append(LOAD_NAME)
-		out.append(envpos%256)
-		out.append(envpos/256)
-		out.append(ROT_TWO)
-
-		# push function:
+		
+		# custop(inst,name,env)  
 		self._const(out, custop, consts)
-		out.append(ROT_THREE)
-
-		# push name as constant:
+		out.append(ROT_TWO)
 		self._const(out, names[ord(code[i+1])+256*ord(code[i+2])],
 			    consts)
-
-		# Call function w 3 args
-		out.append(CALL_FUNCTION)
-		out.append(3)
-		out.append(0)
-		
+		envpos=self._push_env(out, envpos, names)
+		out[len(out):]=[CALL_FUNCTION, 3, 0]
 		i=i+3
 		
-
 	    elif c==LOAD_NAME:
 		out.append(c)
 		out.append(ord(code[i+1]))
@@ -231,28 +208,22 @@ class Eval:
 	out.append(i%256)
 	out.append(i/256)
 
-    def _bfunc(self, out): 
-	out.append(ROT_THREE)
-	out.append(CALL_FUNCTION)
-	out.append(2)
-	out.append(0)
-
-    def _ufunc(self, out): 
-	out.append(ROT_TWO)
-	out.append(CALL_FUNCTION)
-	out.append(1)
-	out.append(0)
+    def _push_env(self, out, envpos, names):
+	# push name of special environment variable, '_env':
+	if envpos < 0:
+	    envpos=len(names)
+	    names.append('_env')
+	out.append(LOAD_NAME)
+	out.append(envpos%256)
+	out.append(envpos/256)
+	return envpos
 
     def eval(self, mapping):
 	d={'_env': mapping}
 	code=self.code
-	validate=self.validate
 	for name in self.used:
-	    try:
-		v=mapping[name]
-		if validate is not None: validate(name, v)
-		d[name]=v
-	    except: pass
+	    try: d[name]=mapping.get(name,0)
+	    except KeyError: pass
 
 	return eval(code,self.globals,d)
 
@@ -297,6 +268,9 @@ BINARY_ADD=23
 BINARY_SUBTRACT=24
 BINARY_SUBSCR=25
 SLICE=	30
+SLICE_b_=	31
+SLICE__e=	32
+SLICE_b_e=	33
 STORE_SLICE=40
 DELETE_SLICE=50
 STORE_SUBSCR=60
@@ -443,6 +417,10 @@ if __name__=='__main__': globals()[sys.argv[1]]()
 ############################################################################
 #
 # $Log: VSEval.py,v $
+# Revision 1.3  1997/10/28 21:51:20  jim
+# Removed validate attribute.
+# Added template dict to override arguments.
+#
 # Revision 1.2  1997/10/27 17:40:35  jim
 # Added some new experimental validation machinery.
 # This is, still a work in progress.