[antlr-interest] Changes in ASTFactory breaks custom AST classes

[Ric Klaren]

Hi,

On Sun, Dec 08, 2002 at 02:44:46PM +0100, Marco Hunsicker wrote:
> class was expanded, but this is the one change that has bitten me).
> 
> 
> 2.7.2a2 looked like
> <pre>
> public AST dup(AST t) {
>     return create(t); // if t==null, create returns null}
> }
> </pre>
> 
> 
> 2.7.2a6 does
> <pre>
> public AST dup(AST t) {
>     if ( t==null ) {
>         return null;
>     }
>     // don't just call
>     AST dup_t = create(t.getClass());
>     dup_t.initialize(t.getType(), t.getText());
>                   // ^
>                   // why not use initialize(t) ???
>     return dup_t;
> }
> </pre>
>   
> 
> The problem (at least for me) lies in the fact that the duplicated
> node gets only initialized with the type and text! All other
> information stored in the original node is lost. I now simply
> override dup(AST) too, changing it back to the old behavior (I only
> use homogenous trees) but I'd rather expect dup(AST) to initialize the
> duplicated node via dup_t.initialize(t) or am I missing something here?

Hmmm I really think that should not be an initialize in there. A (near)
complete copy of the object should be made (in C++ mode I use a clone
method for it that goes through the copy constructor. Dunno if the java
clone does the same thing) The semantics of the clone in C++ are to copy
the object except for the down/right links.

This breaks all tree duplication in java mode. Terence?

Cheers,

Ric
-- 
-----+++++*****************************************************+++++++++-------
    ---- Ric Klaren ----- klaren at cs.utwente.nl ----- +31 53 4893722  ----
-----+++++*****************************************************+++++++++-------
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