Re: [apps-discuss] Fwd: I-D Action: draft-yevstifeyev-ftp-uri-scheme-04.txt

[Mykyta Yevstifeyev <[e-mail]>]

Frank,

I think I'll move the discussion here.  The following is your posting to 
[e-mail]:

> 2011/7/10 Mykyta Yevstifeyev:
>
>>> That can be simplified to:
>>>    !^ftp://([^@]*@)?([^:/?#]*).*$!\\2!i
>> I agree with you here.  Yet, actually this may be simplified
>> far to
>>>    !^ftp://(.*@)?([^:/?#]*).*$!\\2!i

I don't agree with such expression.  See justification below.

> Is "anything ending with '@'" (in your version) the same as
> "any non-'@' ending with the first '@'" (in JimC's version)?
> For clarity I'd prefer the first version, but maybe we are
> not yet ready:
>
>> "@" chars are not generally allowed in in<userinfo>  without
>> percent encoding, as well as in other parts of the URI.
> As soon as you are behind the<userinfo>  in an<authority>
> it is not more necessary to percent-encode '@'.  I'm too lazy
> to check it, but I guess that '@' is an ordinary<pchar>, and
> also allowed in query parts and fragments.

"@" is in <gen-delims>, so we can safely assume that it won't apper 
anywhere else except the authority non-percent-encoded.  As "@"s aren't 
allowed in <userinfo> as by RFC 3986 and my document, it is also assumed 
that there will be no "@" chars before the "@" delimiting userinfo from 
host (if, we can they assume that the second "@" is a part of <host>, 
which isn't allowed as well).  So, "@" will normally occur only 1 time, 
and won't occur in the <userinfo> itself, query or fragment identifier.

>
> After all mailto: and news: URLs use '@' for their purposes
> outside of<userinfo>.
>
> Therefore we might need something in the direction of...
> !^ftp://([^@/?#]*@)?([^:/?#]*).*$!\\2!i
> ...matching '@' only before any path or query or fragment.
> [^@/?#]* should match the colon in a user:pass<userinfo>.

This would make sense if "@" was in <sub-delims>.  See above.

So as a summary: The expression

> !^ftp://([^@]*@)?([^:/?#]*).*$!\\2!i

is sufficient enough to match RFC 3986 and this particular URI scheme.

Mykyta

>
> -Frank
>

14.07.2011 4:48, Frank Ellermann wrote:
> On 11 July 2011 19:27, Mykyta Yevstifeyev wrote:
>
>>> !^ftp://(.*@)?([^:/?#]*).*$!\\2!i
> Sorry, I sent my comment to the uri.arpa list before I saw your
> summary here.  Here's my proposal based on the discussion there:
>
>     !^ftp://([^@/?#]*@)?([^:/?#]*).*$!\\2!i
>
> -Frank
>