W3C home > Mailing lists > Public > uri@w3.org > February 2004

Re: uri handling of hosts is too restrictive

From: Graham Klyne <GK@ninebynine.org>
Date: Thu, 19 Feb 2004 09:17:05 +0000
Message-Id: <>
To: uri@w3.org

At 06:01 19/02/04 +0000, Adam M. Costello BOGUS address, see signature wrote:
>That's fine.  The rule can be: percent-encoding is allowed everywhere
>except the scheme, and individual schemes cannot make exceptions to this

I think that's pretty close to what we have (if permitted normalization is 
taken into account - section

>That paragraph of mine started off more focused, then I generalized it,
>and now I think I'd like to return to the more focused version:
>If an individual scheme restricts a component to contain only ASCII
>characters, then scheme-specific IRI consumers would be required
>to check the component before using it, and fail gracefully if any
>non-ASCII characters are found.
>That's much simpler, requiring only one bit of knowledge about the
>syntax of the component (whether it allows non-ASCII).

So let's try the "running code" test:  this is about *generic* URI syntax, 
and I'm currently implementing a *generic* URI parser.  How am I supposed 
to know whether a particular scheme restricts a particular component in any 
particular way?

Individual schemes, and scheme-specific parsers, are free to impose any 
additional constraints they may see fit, but that's a different issue (cf. 
section 1.1.1).


Graham Klyne
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Received on Thursday, 19 February 2004 05:01:14 UTC

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