[boost] RE: Re: program_options: informative exceptions

From: Vladimir Prus (ghost_at_[hidden])
Date: 2004-09-17 00:52:31

Hi Leo,

> Dear Volodya,
> 
>> I've committed a change which cause the error message to look like:
>> 
>>    error: in option 'compression': invalid option value 'foo'
>> 
>> what do you think? Then only problem is the case where an
>> option has a short
>> version: if you run
>> 
>>    ./first -c foo
>> 
>> then the error message will be exactly the same, which
>> requires the user to
>> mantally link "-c" to "compression". Do you think it's a problem?
> 
> There are always going to be problems where the option name was
> not fully specified on the command line (e.g. --compre 'foo') and
> I had first wondered if it would be possible to echo what was
> actually typed in. This proved to be too much effort.. Otherwise
> you would actually have to remember the parsed item as well as
> which option it mapped to...

I think that technically, this is possible. At least the command line parser
itself provides this information. It's just not stored in the
'basic_option' class. I'll think about this more.

> Do you think option '--compression' is clearer?

In the current situation, no. Since the command line can contain "-c", or
even "/compression", using specific syntax in error message will just add
to confusion. If we're going to show the exact name specified on the command
line, then well, we'll show the syntax used there.

Thanks,
Volodya