[pypy-svn] r45086 - pypy/dist/pypy/lang/scheme

[jlg at codespeak.net]

Author: jlg
Date: Sat Jul 14 17:30:57 2007
New Revision: 45086

Modified:
   pypy/dist/pypy/lang/scheme/object.py
Log:
more instance checking on lst agruments within calls; W_Nil, W_Pair are subclasses of W_list

Modified: pypy/dist/pypy/lang/scheme/object.py
==============================================================================
--- pypy/dist/pypy/lang/scheme/object.py	(original)
+++ pypy/dist/pypy/lang/scheme/object.py	Sat Jul 14 17:30:57 2007
@@ -29,6 +29,8 @@
     pass
 
 class W_Root(object):
+    #__slots__ = []
+
     def to_string(self):
         return ''
 
@@ -159,7 +161,10 @@
     def to_float(self):
         return float(self.intval)
 
-class W_Pair(W_Root):
+class W_List(W_Root):
+    pass
+
+class W_Pair(W_List):
     def __init__(self, car, cdr):
         self.car = car
         self.cdr = cdr
@@ -173,9 +178,14 @@
         oper = self.car.eval(ctx)
         if not isinstance(oper, W_Callable):
             raise NotCallable(oper)
+
+        #a propper (oper args ...) call
+        # self.cdr has to be a proper list
+        if not isinstance(self.cdr, W_List):
+            raise SchemeSyntaxError
         return oper.call_tr(ctx, self.cdr)
 
-class W_Nil(W_Root):
+class W_Nil(W_List):
     def to_string(self):
         return "()"
 
@@ -541,6 +551,8 @@
 
 class Lambda(W_Macro):
     def call(self, ctx, lst):
+        if not isinstance(lst, W_Pair):
+            raise SchemeSyntaxError(lst, "Pair")
         w_args = lst.car
         w_body = lst.cdr
         return W_Lambda(w_args, w_body, ctx)