[Swift-user] question about SwiftScript

[Mihael Hategan]

On Tue, 2007-09-18 at 16:57 +0000, Ben Clifford wrote:
> I would expect you to have some problems there with some stuff that we 
> haven't documented properly with regard to 'closing data sets'.
> 
> Basically: 
> 
> > (file all[]) appl_n (int j)
> > {
> >  if (j == 0) {
> >    all[0] = gen0();
> >  } else {
> >    int k = j - 1;
> >    all = appl_n (k);
> >    all[j] = genn(all[k]);
> >  }
> > }
> 
> when appl_n returns, you can no longer assign anything more to all.
> 
> So you might get problems here:
> 
> >    all = appl_n (k);
> >    all[j] = genn(all[k]);
> 
> because you've assign a value to all in the first line and are now no 
> longer allowed to change it.

That, I believe, is easy to solve:
file[] tmp = appl_n(k);
foreach i in [0:k] {
  all[i] = tmp[i];
}
all[j] = genn(all[k]);

Mihael

> 
> I just added some docs this morning about something that might do 
> something similar to what you are trying to do, which is the iterate 
> language feature.
> 
> Look at this chapter:
> 
> http://www.ci.uchicago.edu/swift/guides/tutorial.php#tutorial.iterate
> 
> on the 'sequential interation construct'.
> 
> I think that corresponds roughly with what you are trying to do, but does 
> it in an iterative style rather than a recursive style.
> 
> (if you want to use this, grab the latest from SVN because I only just 
> committed it and you'd be the first user of this...)
>