W3C home > Mailing lists > Public > ietf-http-wg@w3.org > October to December 2015

Re: ABNF related feedback to: Re: AD review of draft-ietf-httpbis-alt-svc-10

From: Barry Leiba <barryleiba@computer.org>
Date: Thu, 31 Dec 2015 12:40:45 -0500
Message-ID: <CALaySJJuX7geSJE99Wua_cD_O-5ek6p4uuG=OB2nbkrnYHQrYw@mail.gmail.com>
To: Julian Reschke <julian.reschke@gmx.de>
Cc: draft-ietf-httpbis-alt-svc@ietf.org, HTTP Working Group <ietf-http-wg@w3.org>
>>>> NEW
>>>>      alt-authority = DQUOTE [ uri-host ] ":" port DQUOTE
>>>> END
>>>
>>> In HTTP specs, we don't like to use DQUOTE unless the thing being quoted
>>> used quoted-string syntax.
>>
>> I don't understand that.  I particularly don't understand why we'd
>> prefer to specify the content of the string only in the comment, when
>> it's perfectly easy and clear to put it into the ABNF, and have it be
>> verifiable.
>
> There's a two-step process here.
>
> First you need to parse the field value according to HTTP's quoted-string
> rules. The *result* of that parsing needs to validate as
>
>   [ uri-host ] ":" port
>
> There's (IMHO) absolutely no point to force this into a single ABNF
> expression.

OK: We'll go ahead and disagree on this, but I won't argue the point
further.  If anyone else has a comment, let's hear it.  Otherwise,
we'll go with status quo.

>> 3. Do you expect a lot of additional values?  Clearly not, if you're
>> limiting it to ten possible ones.  In that case, as above, I prefer
>> when the ABNF is specific about it.  Consider, for example, RFC 2045's
>> definition of Content-Transfer-Encoding (in Section 6.1):
>>
>>       encoding := "Content-Transfer-Encoding" ":" mechanism
>>
>>       mechanism := "7bit" / "8bit" / "binary" /
>>                    "quoted-printable" / "base64" /
>>                    ietf-token / x-token
>>
>> Here, "mechanism" could have just been defined as << ietf-token /
>> x-token >>, but enumerating the existing values in the ABNF is useful.
>
> I respectfully disagree. For me, (ab)using the ABNF to enumerate values (in
> particular when they are extensible) is an anti-pattern.

OK here too: as with above, status quo unless there are comments from others.

b
Received on Thursday, 31 December 2015 17:41:13 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 1 March 2016 11:11:40 UTC