On 15 Jul., 20:28, Thomas Jollans <tho...@jollans.com> wrote: > On 07/15/2010 07:58 PM, Karsten Wutzke wrote: > > > Hello, > > > this is obviously a Python OO question: > > > Since Python isn't stringly typed, > > I expect this is an innocent typo, and you mean strictly. > > > single-dispatch isn't available per se. So is the "double-dispatch" Visitor > > pattern, >
Yes, typo, I meant strictly. > Wait, what? > First of all, python is strictly typed in that every object has exactly > one type, which is different from other types. So you can't do "1"+2, as > you can in some other languages. > > Anyway, this is interesting: Tell me more about how Python's dynamic > nature makes it impossible to do whatever you're trying to do. I'm > baffled. What are you trying to do, anyway? > > > which is usually used > > in OO systems to implement code generators. So, what is the de facto > > method in Python to handle source code generation? > > WHOA! Now if that isn't a Gedankensprung. Also, I'm still very far from > your train of thought, apparently: Now, the thing that code generators > probably share is that they write code to files. It depends on what I'm > trying to do of course, but I expect there's a good chance that if I > wrote a code generator in Python, it wouldn't be particularly > object-oriented at all. Well, I'm most experienced in OO, so writing OO in Python seems like the way to start with Python. The visitor pattern uses single- dispatch, that is, it determines which method to call be the type of object passed in. I did some reading and it turned out that Python can't do it without some tricks (function decorators and 3rd party code). For what I'm doing, I can't, or rather don't want to rely on 3rd party code (that has reasons). Thus, the visitor OO pattern must be replaced by some other way. As I expected, you already hinted a non-OO solution. Which is now that *I* am wondering what that would look like... Note, that I have an hierarchical object structure which I want to iterate over, so using OO looked natural to me. If there's a better approach, I'm all ears. Karsten -- http://mail.python.org/mailman/listinfo/python-list
