Rob Thorpe wrote: > Pascal Costanza wrote: >> Matthias Blume wrote: >>> Pascal Costanza <[EMAIL PROTECTED]> writes: >>>> (slot-value p 'address) is an attempt to access the field 'address in >>>> the object p. In many languages, the notation for this is p.address. >>>> >>>> Although the class definition for person doesn't mention the field >>>> address, the call to (eval (read)) allows the user to change the >>>> definition of the class person and update its existing >>>> instances. Therefore at runtime, the call to (slot-value p 'adress) >>>> has a chance to succeed. >>> I am quite comfortable with the thought that this sort of evil would >>> get rejected by a statically typed language. :-) >> This sort of feature is clearly not meant for you. ;-P > > To be fair though that kind of thing would only really be used while > debugging a program. > Its no different than adding a new member to a class while in the > debugger. > > There are other places where you might add a slot to an object at > runtime, but they would be done in tidier ways.
Yes, but the question remains how a static type system can deal with this kind of updates. Pascal -- 3rd European Lisp Workshop July 3 - Nantes, France - co-located with ECOOP 2006 http://lisp-ecoop06.bknr.net/ -- http://mail.python.org/mailman/listinfo/python-list
