Re: [Boost-users] Multiple Multitokens

Subject: Re: [Boost-users] Multiple Multitokens
From: David Doria (daviddoria_at_[hidden])
Date: 2009-04-16 07:49:38

I looked into the source to see if I could find what the count() function
was supposed to be doing, but I actually didn't find a count() function at
all?? The usage seems to be "was this parameter set"? But what I'm looking
for is "how many times was this parameter set - ie. how many times did I see
--list?)

Vladimir, you made it sound like po::parse_command_line does not collapse
the multiple parameters, but when you call po::store do they get collapsed?

Thanks,

David

On Wed, Apr 15, 2009 at 7:45 AM, David Doria <daviddoria_at_[hidden]> wrote:

> Volodya, thanks for the help thus far, I think I am close to getting it to
> work.  According to the post you referred me to, multiple of the same
> parameter are not collapsed, ie
> --list a.txt b.txt --list c.txt d.txt
> Should give me access to the two separate lists.
>
> I tried declaring the parameter as usual:
> ("list", po::value<vector<string> >()->multitoken(), "Lists.")
>
> And then I thought it may be the .count property?
>
> cout << "There are " << vm.count("list") << " lists." << endl;
>
> But there is only 1 list.
>
> The idea was to do this:
>
> vector<vector<string> > lists;
>     for(unsigned int list = 0; list < vm.count("list"); list++)
>     {
>         vector<string> l = vm["list"].as<vector<string> >();
>         lists.push_back(l);
>
>         for(unsigned int item = 0; item < lists[list].size(); item++)
>             cout << "List: " << list << " Item: " << item << " " <<
> lists[list][item] << endl;
>     }
>
> Clearly I am still missing the part about accessing the separated "list"
> params.  Can you see the problem here?
>
> Thanks,
>
> David
>
>>
>> David Doria wrote:
>>
>> > I want to do something like this:
>> > --NumLists 2 --List0 a.txt b.txt --List1 c.txt d.txt
>> >
>> >     vector<vector<string> > Lists(2);
>> >
>> >     po::options_description desc("Allowed options");
>> >     desc.add_options()
>> >             ("help", "produce help message")
>> >             ("List0", po::value<vector<string>
>> >(&Lists[0])->multitoken(),
>> > "List0.")
>> >             ("List1", po::value<vector<string>
>> >(&Lists[1])->multitoken(),
>> > "List1.")
>> >             ;
>> >
>> > But if I wanted to handle --NumLists 10, I would have to manually add
>> List0,
>> > List1, ... List10 as parameters. That seems a bit silly, but maybe this
>> is a
>> > very odd usage?
>>
>> Well, it's somewhat odd :-)
>>
>> > Please let me know if you can think of a better way to
>> > handle this.
>>
>> Well, as a remark, your command line interface will make users cry:
>>
>> - Do you really want users to type uppercase letters? (Use can use
>>  case-insensitive mode, of course, and allow any spelling, but upper
>>  case in your example seems strange.
>> - Do you really want users to count lists and pass 0, 1, 2, etc
>> explicitly?
>> - Why do you need explicit specification of the number of lists?
>>
>> I'd use:
>>
>>        --list a.txt b.txt --list c.txt d.txt
>>
>> You might find the recent thread useful for handling such command lines:
>>
>>        http://permalink.gmane.org/gmane.comp.lib.boost.user/46405
>>
>> - Volodya
>>
>>
>>
>