[boost] Re: Formal Review: Command Line & Config library

From: Vladimir Prus (ghost_at_[hidden])
Date: 2003-05-23 00:15:58

Hi Pavol,

Pavol Droba wrote:
> I have tried to use program_options library. I have compiled the library,
> ran the examples and then incorporated the library into one of my
> projects.

Thanks for putting time into this!

> First and in my opinion the most important one is the matter of
> documentation. I find it very hard to use. Examples are quite good to give
> a nice overview of the library and that's sufficient for a decent start.
> But searching for the details is quite difficult. I would prefer a few
> chapters explaining various components of the library, each followed by a
> reference. Right now I find the documentation rather hard to use. Actuay
> it is very close to browsing through header files and in my opinion this
> is not what the documentation should be about.

I'll keep this in mind. In fact, I plan to convert all the documentation
into BoostBook is the library is accepted. The Doxygen is very nice --- in
fact, it helps very much to keep everything documented. But I found it
rather limiting for writing various "overview" pages. Hope new
documentation will be better.

[...]
> * Arguments
> 
>    As it was already mentioned here, arguments should have the same
>    support as options. Validation and format checking would be appretiated

OK, I'm already thinking about possible approaches.

> * Validation
>    
>    Library allows to supports validation and parsing of option parameters,
>    but I thinks it is rather limited. It is possible to define
>    user-specific behaviour, but it would be helpful, if some common
>    formats would be suported.
> 
>    For instance:
>       * Various integer types ( not just int ) with boundary checking.
>         Something like
>                paramter<int>( "count", 1, 4, &count ) // 1-Min and 4-Max
>                value

It's funny that the very first prototype version had this facility. In
surely can be added to the current version if there's such need.

>       * Format specification and checking for string. Regex specification
>       of something like scanf would be nice.
>         This can be useful for example to check if the parameter is a
>         filename.

Could you clarify a bit how scanf-like specification can work? You mean it
can be used to specify syntax? 

> * Environment & Others
> 
>    The library tries to unify the access to program options from command
>    line and from ini files. This is very nice feature because it is
>    removing the need for doing generaly the same thing twice. It would be
>    nice if some other sources of paramers could be incorporated as well.
>    Particulary the enviromnmet is often used to exchange arguments. Given
>    the fact that it consist of a set of pairs "variable=value" it is very
>    similar to the ini file and so it souldn't be hard to implement.

Thanks for the suggestion! It's quite right.
 
>    For windows platform the registry comes to play as another source of
>    options.

Yep, that source was considered as alternative from the very start. I've
seen some project start with a command line, then add config files and then
need registry on Windows. Registry is not yet supported because I wanted to
find out if there's support to the idea of uniform access to all
configuration means.

Thanks,
Volodya