Joachim Durchholz wrote: > Chris Smith schrieb: >> Joachim Durchholz <[EMAIL PROTECTED]> wrote: >>> Sorry, I have to insist that it's not me who's stretching terms here. >>> >>> All textbook definitions that I have seen define a type as the >>> set/operations/axioms triple I mentioned above. >>> No mention of immutability, at least not in the definitions. >> >> The immutability comes from the fact (perhaps implicit in these >> textbooks, or perhaps they are not really texts on formal type theory) >> that types are assigned to expressions, > > That doesn't *define* what's a type or what isn't! > > If it's impossible to assign types to all expressions of a program in a > language, that does mean that there's no useful type theory for the > program, but it most definitely does not mean that there are no types in > the program. > I can still sensibly talk about sets of values, sets of allowable > operations over each value, and about relationships between inputs and > outputs of these operations. > > So programs have types, even if they don't have a static type system. > Q.E.D. >
Of course not. Otherwise programs using dynamically typed systems wouldnt exist. > Regards, > Jo I haven't read all of this thread, I wonder, is the problem to do with Class being mistaken for Type? (which is usually the issue) -- http://mail.python.org/mailman/listinfo/python-list
