Re: [boost] command line parameters parser

Subject: Re: [boost] command line parameters parser
From: Vladimir Prus (ghost_at_[hidden])
Date: 2010-03-04 07:23:11

Denis Shevchenko wrote:
> Christoph Heindl wrote:
>  > Hi Denis
>  >
>  > How does your library compare to Boost.Program_options [1]?
>  >
>  > -- Christoph
>  >
>  > [1] http://www.boost.org/doc/libs/1_42_0/doc/html/program_options.html
>  >
> 
> Hi, Christoph!
> 
> I now about Boost.Program_options, and use it in my programs some time. 
> But later I decide create my own solution, because Boost.Program_options 
> have some limitation.
> 
> First, it cannot call functions/functors. If I put in command line some 
> parameter, I want some reaction on it. In my lib reaction occure 
> immediately, in parsing process (but after all correction checks). Lib 
> know nothing about this reaction's semantic, it just call correspond 
> boost::signal.

Oh? Surely there's typed_value::notifier that allows to specify callbacks.

> Second, it cannot check "value semantic" of parameters. If parameter's 
> value must be a valid path (or valid IPv4, or some else), I may want to 
> check it immediately, in parsing process. In this case, my lib checks 
> value's validity (using Boost.Filesystem, or my own algorithms) and, if 
> error occurs, generate correspond std::exception.

It it unclear to me why you insist on doing such checks during the parsing.
ProgramOptions performns such checking when parsed tokens are stored
in variables_map, which seems like a sensible separation of responsibilities
to me.

- Volodya