[Microid] Augmented Backus-Naur Form Scheme issues?

Yaniv Golan yaniv at yedda.com
Wed Aug 15 00:11:25 EDT 2007


Oops. I actually think the "+" thing was my proposal, and therefore my
fault. Sorry about that :)

Because there are no current schemes using "+", I vote +1 for option
#2 (Provide guidance for handling of "+"), and I suggest specifying
that the schema name should be URL-encoded, so that "+" will become
"%2B". 

Yaniv

--
Yaniv Golan
CTO, Yedda | http://yedda.com
e: yaniv at yedda.com | m: +972-54-4-548-249 | my yedda:
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> -----Original Message-----
> From: microid-bounces at lists.ibiblio.org [mailto:microid-
> bounces at lists.ibiblio.org] On Behalf Of Peter Saint-Andre
> Sent: Wednesday, August 15, 2007 12:45 AM
> To: Brian Suda
> Cc: microid at lists.ibiblio.org
> Subject: Re: [Microid] Augmented Backus-Naur Form Scheme issues?
> 
> Brian Suda wrote:
> > i did a quick search through the archives and didn´t find
> anything
> > http://www.google.is/search?hl=is&client=firefox-
> a&rls=org.mozilla%3Aen-
> US%3Aofficial&hs=Q5N&q=site%3Ahttp%3A%2F%2Flists.ibiblio.org%2Fpi
> permail%2Fmicroid%2F+scheme&btnG=Leita&lr=
> >
> > Can some one confirm that this is not actually an issue, or
> that it
> > doesn´t matter that it is?
> >
> > According to the scheme:
> > inputs  = scheme "+" scheme
> > scheme  = ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )
> >           ; a URI scheme name (e.g., mailto)
> >
> > you can have multiple schemes separated by a + symbol, but the
> scheme
> > itself can have a + in it. For example:
> >
> > svn+ssh as one scheme, concatenated + with a second scheme,
> https
> >
> > that would be svn+ssh+https, how would you know that is svn+ssh
> and
> > not ssh+http? or is that even an issue?
> 
> That is a good catch. Section 3.1 of RFC 3986 defines scheme as
> follows:
> 
>    scheme = ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )
> 
> So you're right that "+" is allowed in the scheme name. Clearly
> we did
> not check the URI syntax when we defined the MicroID syntax, and
> a quick
> check of the IANA registry would have revealed no schemes with
> "+" in
> the name:
> 
> http://www.iana.org/assignments/uri-schemes.html
> 
> We should have chosen a character that's not allowed in "scheme",
> such
> as "_".
> 
> But I'm not sure what to do about it now. We could:
> 
> 1. Change the separator to "_" or somesuch.
> 
>    Pro: Conforms to RFC 3986.
>    Con: Breaks existing implementations.
> 
> 2. Provide guidance for handling of "+".
> 
>    Pro: Doesn't break existing implementations.
>    Con: Potentially confusing; does not conform to RFC 3986.
> 
> The spec writer in me likes (1), but the documentation guy in me
> prefers
> (2) since I really don't like to break existing implementations.
> 
> Peter
> 
> --
> Peter Saint-Andre
> https://stpeter.im/
> 




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