John Nagle: >I gave up on this when C came in; the C crowd was so casual about integer >overflow that nobody cared about this level of correctness. Today, of course, >"buffer overflows" are a way of life.<
Experience shows that integer overflows are a very common bug. One of the huge advantages of Python is that it frees the programmer to keep a constant eye on the size of the numbers (so multi-precision numbers aren't just for cryptography as I often hear people say, they are wrong). This helps me avoid a class of bugs and program faster and in a more relaxed way. Some C# designers come from Pascal (where overflow is considered an important thing), and they have added to dotnet ways to find when an overflow occurs, globally in a program, locally in a piece of code, or even in a single part of an expression. This is much better than nothing. Languages like Lisp (and some other, like some modern forths, etc) avoid most of the trouble with tagged integers, they are a bit slower but have the advantages of letting you forget the finite nature of integers (and in Lisp you can often ask for a fixnum where you need max performance anyway). Later some people has even seen that a sufficiently smart compiler can even remove part of the controls to find the overflows (for example where you use a variable that you can infer will never overflow). I'm fighting against the C/C++ crowd to add C#-like integer overflows to the D2 language, but with not much luck so far, all they (Walter, mostly) see is the "lower performance" it may lead. Bye, bearophile -- http://mail.python.org/mailman/listinfo/python-list
