Re: [apps-discuss] Scope of RFC3986 and successor - what is a URI?

[Julian Reschke <[e-mail]>]

On 2015-01-16 17:32, Sean Leonard wrote:
>
> On Jan 16, 2015, at 8:23 AM, Daniel Stenberg <[e-mail]> wrote:
>
>> On Fri, 16 Jan 2015, [e-mail] wrote:
>>
>>> Here is something that round-trips a URL parse/stringify transformation, and actually works, despite being an invalid URI and invalid IRI:
>>>
>>> https://www.google.com/?q=[z]
>>>
>>> My gut feeling is that allowing this to be valid is a possible change, as I've said. I appreciate this is at odds with RFC 3986, but if URL parsers do generally ignore the error that's fine.
>> ̈́
>> $ curl 'https://www.google.com/?q=[z]'
>> curl: (3) [globbing] bad range in column 32
>>
>> This isn't strictly the URI parser saying this, but since we know that [] are not legal in a URI we (curl developers) could use them for additional functionality...
>>
>> Just suggesting that changing this will make some things break.
>
> Yes that is an excellent point. In my own software I use some of those properties of URIs. Since certain characters like { } [ ] < > are not part of URIs, they can be used to develop new functionality (e.g., URI regexps). For example [z] can mean “escape the z variable string in UTF-8” vs  {z} “escape the z variable octet array as-is”, or other variations. And of course { }, < >, and the like can be used to delineate an URI in other contexts, such as in plain text <http://this.is.a.uri.com/foo>.

"{" and "}" are used in URI templates.

Re square brackets, see for example: 
<http://stackoverflow.com/questions/40568/square-brackets-in-urls>

Best regards, Julian