Re: [Opencxx-users] future directions

[Stefan S. <se...@sy...>]

Grzegorz Jakacki wrote:

>> And I don't see a problem having two separate constructors, one operating
>> on Ptree pointers, the other on the typed counterpart.
> 
> 
> I am not sure if you get the exact picture. The "untyped" constructor 
> does not construct the NonLeaf auxiliary nodes. It is just:
> 
> 
>     PtreeIfStatement(Ptree* p, Ptree* q) : NonLeaf(p, q) {}
> 
> If we have another, "typed" constructor like this one:
> 
>     PtreeIfStatement(
>         PtreeExprStatement* cond
>       , PtreeExprStatement *th
>       , PtreeExprStatement* el
>     )
>       : NonLeaf(cond, new NonLeaf(th, new NonLeaf(el, NULL)))
>     {}
> 
> Then, as you noticed, there is a question of who owns auxiliary
> NonLeaf nodes (and, consequently, if ~PtreeIfStatement should delete them).

right, but I didn't mean the 'typed constructor' to construct any nodes
himself, but rather to take 'PtreeExprStatement' arguments instead of 'Ptree'.
The ownership semantics remains the same.

>> That sounds indeed like a bad idea. Either Ptrees
>> own their children, or they don't. 
> 
> 
> I agree. However I am not sure what you mean by "child". What is a 
> "child" of PtreeIfStatement node? Do you consider "else-part" to be a 
> "child" of PtreeIfStatement node?

yes.

> It is also not clear to me if you would like to keep the existing 
> representation of if-statement as three physical nodes or if you 
> eventually would like to modify PtreeIfStatement so that it becomes
> 
> struct PtreeIfStatement
> {
>     ...
>     PtreeExprStatement *cond_, *then_, *else_;
> };

the latter.

Regards,
		Stefan