Re: [cpp-netlib-devel] Proposal: Utilities Directory

[Dean M. B. <mik...@gm...>]

On Fri, Feb 12, 2010 at 12:27 AM, Jeroen Habraken <vex...@gm...> wrote:
> Hi guys,
>
> On Thu, Feb 11, 2010 at 15:25, Dean Michael Berris
> <mik...@gm...> wrote:
>> I was thinking about this a little and thought it would be cool to
>> have a collection of utilities of commonly-performed actions that
>> others might find useful in the library. Off the top of my head I find
>> that these would be cool functions/mini-libraries to have:
>
> This would be very nice indeed. Also, in my opinion, we need a few
> more code examples as I've generally found them to be a good way to
> familiarize yourself with a library. Something like a simple HTTP
> proxy might even fall in both categories, showing off both the client
> and server side of the library.
>

Code examples are definitely good to have. I'm a little afraid though
that we'd ruffle a few feathers if we implemented something like this.
I've been meaning to do a wicked fast static HTTP server that competes
with lighttpd/nginx in simplicity and performance. My worry would be
that it would be a project that would have its own demons. ;)

>
> The query parser is indeed one of the things currently on the TODO
> list for the URI part of the library. Design-wise I was thinking of
> something like:
>
> template <class Tag>
> bool parse_query(basic_uri<Tag> const & uri, typename query_list<Tag>::type &) {
>  // TODO Parse using Spirit
>
>  return true; // Return whether it was successful.
> }
>
> with
>
> template <class Tag>
> struct query_list {
>  typedef typename string<Tag>::type string_type;
>
>  typedef typename std::list<std::pair<string_type, string_type> > type;
> }
>
> and something along the same lines  for query_map for a std::map. This
> is off the top of my head, and your thoughts would be very much
> appreciated. As I've said before, most of the grunt work has already
> been done by Hartmunt in this brilliant article:
> http://boost-spirit.com/home/articles/qi-example/parsing-a-list-of-key-value-pairs-using-spirit-qi/
> thus with some luck this is actually rather easy.
>

Sure, but it just assumes the "canonical" form of "key=value&foo=bar".
There's a lot more to query strings than just this form (some use
different delimeters, instead of &, some use |, there's also list and
multi-form notation like "form1[field]=value&form2[field]=value" and
all sorts of funky things). That in itself sounds like a pretty
useful/powerful set of parsers that would definitely make for an
interesting project.

Now I'm seriously considering applying for a Google Summer of Code
thing to get support for the project. :D Maybe after BoostCon and once
more people get to use the library more. ;)

> Secondly, I have the basis of a dispatcher I wrote for libevent
> bindings some time ago, which I've attached. There seem to be a few
> things which need to be abstracted from though:
> - The comparison function
> - The type you're comparing to
> and quite probably a few more things, as ultimately I'd be very useful
> if you could stick in boost::starts_with, something from the regex
> library or from the xpressive library to find a match. If anyone finds
> this code is of any use for cpp-netlib, I'll stick a boost license on
> it.
>

I haven't looked at it yet, but I have a somewhat dormant header-only
library on SourceForge that does pretty much something similar (It's
called the Runtime Dynamic Dispatch Library). I'm looking for
something more flexible though, something that allows me to map a
boost::regex string that contains sub-groups (or named groups) to a
function that has the signature: void(request const &, response &).

Does your implementation do roughly that?

I might come up with a simple implementation and place it in
boost/network/utils -- when I get time to do so that is. ;)

>> Any takers? It would be cool if we had these in the library before May
>> where I will be presenting the library and the techniques used in the
>> library at a high level. ;)
>
> This is where things get tricky, considering I've just got an
> apartment this month and will be moving, I'm quite limited when it
> comes to free time unfortunately.
>

I can understand that completely, having been in that situation
before. May is still a ways away -- you've got time in between now and
then. :D

>> Hope this helps and I hope to hear from you guys soon too!
>>
>
> Hope this is of any use,

I'll take a look and I encourage others in the list to do the same. :)

-- 
Dean Michael Berris
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