Re: [Axiom-developer] hypertex and uses info

[Waldek Hebisch]

Vanuxem Grégory wrote:
> Waldek,
> 
> > All versions of hypertex that I used crashed (or maybe showed 
> > nothing) 
> > when I clicked "Uses" or "Dependants" field in a description of a 
> > constructor.
> 
> > AFAICS recent versions of Axiom have two problems here:
> 
> > 1) databases which contain corresponding information (USERS.DAASE
> >    and DEPENDENTS.DAASE) were not installed
> > 2) infamous 'probe-file' problem
> 
> > The patch below correct both problems. It also fixes the
> > "Cannot rename the file erlib to NRLIB" problem. I also added
> > sensible dependency in database rule, so that all databses
> > are re-made when one get out of date. And 'RDEFIOSTREAM' is
> > now called in error-checking mode (old code happily passed
> > bad pathnames and supressed error checking).
> 
> I'm in the process of applying these patches. Do you know a situation where
> readLibPathFast is used on a non existent file ? Since you prefer to remove
> some assumptions, I want to know :-)
>

The prime example is if you forget to install USERS.DAASE or
DEPENDENTS.DAASE, even with probe-file problem resolved you
still get crash.

BTW 1: I would say that somebody making an assumption should justify
it (and the assumption is completly unjustified, as the pathname
does no error checking).

BTW 2: Expensive part of error checking in RDEFIOSTREAM is done
anyway, so there is no excuse to skip cheap error check.

BTW 3: IMHO the approach check first and then go on without checking
has fundamental problems, Unix way "try and check if OK" works
much better.

-- 
                              Waldek Hebisch
address@hidden