Re: java.lang.NullPointerException when loading SSAX.scm inkawa-1.7

[Stan Pinte <stan at altosw dot be>]

On Mon, 07 Jul 2003 02:04:55 -0700
Jim White <jim@pagesmiths.com> wrote:

> Stan Pinte wrote:
> > On Fri, 04 Jul 2003 16:09:27 -0700
> > Jim White <jim@pagesmiths.com> wrote:
> > 
> >>Stan Pinte wrote:
> >>
> >>>when loading SSAX.scm, I am getting the following:
> >>>
> >>>java.lang.NullPointerException
> >>>        at gnu.expr.LambdaExp.allocChildClasses(LambdaExp.java:936)
> >>>...
> >>
> >>The problem occurs at the second "test".  If there is just one then it
> >>compiles OK.
> > 
> > any idea why? It could be great to have Kawa run the test suite without any problem!
> 
> It has something to do with this code at gnu.expr.LambdaExp(935):
> 
>     LambdaExp owner = this;
>     while (owner.heapFrame == null)
>        owner = owner.outerLambda();
>     closureEnvType = (ClassType) owner.heapFrame.getType();
> 
> Which might need to look something like this:
> 
>     LambdaExp owner = this;
>     while (owner.heapFrame == null) {
>        owner = owner.outerLambda();
>        if (owner == null) {
>           // Do something about the heap frame situation.
>        }
>     }
>     closureEnvType = (ClassType) owner.heapFrame.getType();
> 
> But I don't know enough about Kawa compilation to understand if this 
> where the fix goes or if this is just symptomatic.  It has something to 
> do with the closure situation with siblings and let forms but that's all 
> Greek to me.
> 
> Per is on vacation and I'm sure he'll provide a fix as soon as he gets 
> back in a few days.  If you had to make this run before then, you could 
> rewrite the code to just put each test in its own lambda or something. 
> A macro could do the job one way or another I'm sure.

Thanks a lot for your help, Jim!!!

I'll wait for Per coming back from vacations without problems, as I can use other Scheme systems with SSAX in the meantime, but it would be great to have it fixed!

thanks again.

Stan.

> 
> Jim
> -- 
> "I love deadlines. I love the whooshing sound they make as they fly by." 
> -- Douglas Adams
> 
>