Re: Proposal: make Glib::KeyFile easier to use

[Aurimas Cernius <aurisc4 gmail com>]

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Hi,

> > One external thing to consider here is "who edits key files". I
> > don't expect non-pro guy doing anything there, so key files
> > probably are unlikely to be broken (low probability).
>
> Yes, but I still don't want stack unwinding to occur. In my use
> case the rest of the key file must still be read successfully. If
> it was possible to give up on errors I would move error handling
> somewhere higher up in the call stack and use exceptions.

You can wrap every individual call to get_* with try-catch (write your
own helper function for this). Should such convenience method be part
of Glibmm itself is a debate, of course.


> > Do think that "if" is more convenient that "try-catch"? I'm not
> > sure about that. If you think of more convenient getter for key,
> > I'd think of passing default value as last argument, that would
> > be returned in case key is missing or not valid. I think that
> > would cover most of the cases, the remaining few could deal with
> > exceptions.
>
> Yes, I think that a simple conditional is a better approach in
> this specific use-case: * Using exceptions to rewind the stack by
> one level is fundamentally wrong. One can do that, but that's not
> idiomatic C++.

No, that's what exceptions were designed for. What is wrong is
wrapping every statement in try-catch.


> * Using a default value is not workable when the range of input
> data must not be reduced (which is one of my requirements).

I don't quite understand what you're trying to achieve. Your point is
to make Glib::KeyFile "easier to use", but I don't really see, how
your proposal achieves that. Returning a wrapper object and writing if
to check it's value does not seem to be "easier" than wrapping a call
in try-catch:

int val;
try {
  val = key_file.get_integer("a", "b");
}
catch(Glib::KeyFileError &) {
  val = 0;  // let this be default value
}


int val;
auto opt = f.get_integer_opt("a", "b");
if(opt) {
  val = *opt;
}
else {
  val = 0;  // let this be default value
}


As you can see, your proposal in my case result in more code.
Can you present a use-case, where it makes things easier?

- -- 
Aurimas
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