Curl support RFC

[Jonas Drewsen]

On 14/03/11 16.40, Johannes Pfau wrote:
> Jonas Drewsen wrote:
>>> Do you plan to add some kind of support for header parsing? I think
>>> something like what the .net webclient uses
>>> ( http://msdn.microsoft.com/en-us/library/system.net.webclient(v=VS.100).aspx )
>>> would be great. Especially the HeaderCollection supporting headers as
>>> strings and as data types (for both parsing and formatting), but
>>> without a class hierarchy for the headers, using templates instead.
>>
>> It would be nice to be able to get/set headers by string and enums
>> (http://msdn.microsoft.com/en-us/library/system.net.httprequestheader.aspx).
>> But I cannot see that .net is using datatypes or templates for it.
>> Could you give me a pointer please?
>>
>
> You're right I didn't look close enough at the .net documentation. I
> thought HttpRequestHeader is a class. What I meant for D was something
> like this:
>
> struct ETagHeader
> {
>      //Data members
>      bool Weak = false;
>      string Value;
>
>      //All header structs provide these
>      static string Key = "ETag";
>
>      static ETagHeader parse(string value)
>      {
>          //parser logic here
>      }
>
>      void format(T writer)
>          if (isOutputRange!(T, string))
>      {
>          if(etag.Weak)
>              writer.put("W/");
>          assert(etag.Value != "");
>          writer.put(quote(etag.Value));
>      }
> }
>
> Then we can offer methods like these:
>
> setHeader(T)(T header)
>      if(isHeader(T))
> {
>      headers[T.Key] = formatHeader(header);
> }
>
> T getHeader(T type)()
>      if(isHeader(T))
> {
>     if(!T.Key in headers)
>         throw Exception();
>     return T.parse(headers[T.key]);
> }
>
> So user code wouldn't have to deal with header parsing / formatting:
> auto etag = client.getHeader!ETagHeader();
> assert(etag.Weak);

Seems like a very nice addition. I will have a look at your github and 
probably wait until you have made it ready for consumption before adding 
it :)

>>> I've written D parsers/formatters for almost all headers in
>>> rfc2616 (1 or 2 might be missing) and for a few additional commonly
>>> used headers (Content-Disposition, cookie headers). The parsers are
>>> written with ragel and are to be used with curl (continuations must
>>> be removed and the parsers always take 1 line of input, just as you
>>> get it from curl). Right now only the client side is implemented (no
>>> parsers for headers which can only be sent from client-->server ).
>>> However, I need to add some more documentation to the parsers, need
>>> to do some refactoring and I've got absolutely no time for that in
>>> the next 2 weeks ('abitur' final exams). But if you could wait 2
>>> weeks or if you wanted to do the refactoring yourself, I would be
>>> happy to contribute that code.
>>
>> That sounds very interesting. I would very much like to see the code
>> and see if fits in.
>
> Ok, here it is, but it seriously needs to be refactored and documented:
> https://gist.github.com/869324
>