- From: Larry Masinter <LMM@acm.org>
- Date: Fri, 19 Mar 2004 09:20:38 -0800
- To: "'Michel Suignard'" <michelsu@windows.microsoft.com>, public-iri@w3.org, uri@w3.org
It seems like a pretty big change to the IRI concept to have IRI -> URI transformations use scheme-specific knowledge. Formerly, IRI -> URI transformation was specified as scheme independent. I understand that this seems necessary because of IDN, but it's a big concern. And to use "SHOULD" would leave us subject to the indeterminate knowledge of which method is going to be used. If you believe that IRI->URI needs to be scheme specific, then is it really tractable to define IRI as a generic concept? Do we need a separate spec for "http:", "mailto:", "ftp:" IRIs, where each specifies the punycode vs. hex-encoding of the various parts? For example, a 'data' IRI might need a separate specification for the default MIME type (since text/plain defaults US-ASCII). And an IRI URN might also have a different mapping, etc. Larry > > > Adam, I think you have a valid point, I would however make a > simpler suggestion, which is two fold: > > - introduce the concept of IRI used as presentation element > of URI protocol element. In that sense > http://josé.example.net/ is a presentation element for the > following protocol element http://xn--jos-dma.example.net/ > and as you noted http://jos%C3%A9.example.net/ is not a > correct URI (per RFC 2616 referring to host itself defined in > RFC 2396). I have suggested text in that sense to the IRI > main editor (Martin). Having the concept of presentation > element validates http IRIs which exist de facto, whatever we > like it or not. > > - add text in the IRI spec saying the following: > << > When an IRI is converted to a URI, the conversion SHOULD use > scheme-specific knowledge to convert appropriate components > where the scheme syntax prevents the usage of percent-encoded > text into such components. Lack of scheme-specific knowledge > (or failure to use it) can cause valid IRIs to be converted > to invalid URIs that contain percent-encoded non-ASCII text > where they are not permitted. > >> > It is my opinion that anybody in its right mind would > implement IRI to URI mapping considering all the schemes > where 'host' is used and map accordingly (ie use Punycode). > My text avoids direct reference to ACE which is in my opinion > unnecessary in the IRI spec and also makes the suggestion to > use scheme aware mapping much stronger (SHOULD instead of > MAY). It is a SHOULD instead of a MUST simply because a > scheme may be updated in the future, making the scheme > awareness eventually not necessary. > > Michel
Received on Friday, 19 March 2004 12:21:18 UTC