- From: Roy T. Fielding <fielding@gbiv.com>
- Date: Thu, 1 Apr 2004 16:56:53 -0800
- To: Graham Klyne <GK@ninebynine.org>
- Cc: uri@w3.org
> I'll try this out when I have some time... it may be a week or so.
> meanwhile, a quick point of confirmation concerning:
> [[
> If a URI contains an authority component, then the path component must
> either be empty or begin with a slash ("/") character. If a URI does
> not contain an authority component, then the path cannot begin with
> two slash characters ("//"). In addition, a URI reference (Section
> 4.1) may begin with a relative path, in which case the first path
> segment cannot contain a colon (":") character. The ABNF requires five
> separate rules to disambiguate these cases, only one of which will
> match a given URI reference. We use the generic term "path component"
> to describe the URI substring that is matched by the parser to one of
> these rules.
> ]]
>
> This suggests to me that the minimal authority "//" is distinct from
> having no authority at all, which I think is fine. In particular, I
> think the above text means that it is not OK to remove a minimal "//"
> authority from a URI. (I always believed this to be the case, but I
> have encountered software that does remove "blank" authorities.)
They are certainly distinct for parsers -- otherwise, there would be no
way to round-trip the parsed version back to a reference. However,
normalization is a different creature. It might be okay to remove an
empty authority if such an equivalence is defined for the scheme,
as it is for a file URI if the path does not begin with "//".
....Roy
Received on Thursday, 1 April 2004 20:26:39 UTC