Identifying a class type - bad practice?

[Bruno Desthuilliers]

James Harris a écrit :
> On 18 Aug, 21:50, Chris Rebert <c... at rebertia.com> wrote:
(snip)
>> class node_type_1:
>>     def walk_tree(self):
>>         #code
>>         self.subtree.walk()
>>
>> class node_type_2:
>>     def walk_tree(self):
>>         #code
>>         self.subtree.walk()
>>
>> #etc
> 
> Interesting idea.

Basic OO stuff, really. I'd say it's even the whole point of OO.

(snip)

> The tree is for a compiler. Initially the tree is for parsing of
> source code. Then it will need to be processed and changed as further
> compiler phases are written. I don't know yet whether it will be
> easier to modify the tree or to create a new one for each phase.
> 
> So I guess whether I use the idea depends on the commonality of
> operations.

You may want to have a look at the "composite" and "visitor" design 
patterns. AST are canonical use case for these patterns.


HTH