On 5/8/07, Jason Orendorff <[EMAIL PROTECTED]> wrote: > On 5/7/07, Guido van Rossum <[EMAIL PROTECTED]> wrote: > > I don't know how this will work out yet. I'm not convinced that having > > both mutable and immutable bytes is the right thing to do; but I'm > > also not convinced of the opposite. I am slowly working on the > > string/unicode unification, and so far, unfortunately, it is quite > > daunting to get rid of 8-bit strings even at the Python level let > > alone at the C level. > > Guido, if 3.x had an immutable bytes type, could 2to3 provide a > better guarantee? Namely, "Set your default encoding to None > in your 2.x code today, and 2to3 will not introduce bugs around > str/unicode."
I don't know. I may be able to tell you when I'm further into the process of unifying str and unicode. > 2to3 could produce 3.x code that preserves the 2.x meaning by > using 2.x-ish types, including immutable byte strings. This sounds dangerously close to crippling 3.0 with backwards compatibility. I want to reserve this option as a last resort. > Without this, my understanding is that 2to3 will introduce bugs. > Am I wrong? No -- 2to3 cannot guarantee that your code will work correctly, because it doesn't do any data flow analysis or type inferencing. This is not limited to strings. > This might be worth doing even if you decide an immutable 8-bit > type is wrong for the core language. The type could be hidden > away in an "upgradelib" module somewhere. Surely people will > prefer correctness over "producing nice, idiomatic 3.x code" > in the 2to3 tool. With that I agree, at least in general (e.g. d.keys() gets translated to list(d.keys()) and d.iterkeys(0 to iter(d.keys())). In the current py3k-struni branch I have temporarily kept the 8-bit string type around, renamed to str8. I am hoping I will be able to get rid of it eventually but I may not succeed and then we'll have it available as a backup. For anyone who wants to discuss this more -- please come and help out in the py3k-struni branch first. It is simply too soon to be able to make decisions based on the evidence available so far, and I won't be forced. -- --Guido van Rossum (home page: http://www.python.org/~guido/) _______________________________________________ Python-3000 mailing list Python-3000@python.org http://mail.python.org/mailman/listinfo/python-3000 Unsubscribe: http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
