Re: [boost] [filesystem] #6521 Directory listing using C++11 range-based for loops

Subject: Re: [boost] [filesystem] #6521 Directory listing using C++11 range-based for loops
From: Beman Dawes (bdawes_at_[hidden])
Date: 2012-04-20 08:35:38

On Fri, Apr 20, 2012 at 5:24 AM, Thorsten Ottosen
<thorsten.ottosen_at_[hidden]> wrote:
> On 20-04-2012 10:12, Thorsten Ottosen wrote:
>>
>> On 19-04-2012 17:29, Beman Dawes wrote:
>
>
>> then we could add
>>
>> boost::iterator_range<...>
>> boost::directory_range( const boost::path& )
>> boost::iterator_range<...>
>> boost::recursive_directory_range( const boost::path& )
>
>
> Then, if we wanted to make a really user-friendly interface, we could add
>
> boost::iterator_range<...>
> boost::directory_range( const boost::path&, const boost::path& extension )
>
> support for multiple extensions or reguar expression would be cool, e.g.
>
>   boost::directory_range( "some_path/", "(.txt|.doc|.jpg)" )

Cool!

But:

> and support for the reverse sitution
>
> boost::iterator_range<...>
> boost::directory_range( const boost::path&, const boost::regex& toExclude )

is even better:-)

> Especially for recursive iteration, it is useful to skip entire directories.

Mind-blowing! Your suggestion is getting very close to a solution for
the general directory search problem I've wrestled with for years.

What we would really like is to be able to apply a series of filters,
some of which apply to directories, some to files. Examples are your
include|exclude regex filters, applicable to directories|files|both.
Another filter might be a file filter <=|>= a given size. Dates and
permissions filters would also be useful. Perhaps user supplied
filters. And how about filters applied to the contents of files?

> Remark: such support is probably most naturally added to the underying
> iterator classes by storing some boost::optional<> variables.

I'll need to think about that - it will take me a while to digest this.

Thanks,

--Beman