From: Charles Lindsey (chl@clw.cs.man.ac.uk)
Date: Mon Feb 04 2002 - 05:09:21 CST
In <7cKPhbFkxmW8QAmq@pillar.turnpike.com> Paul Overell <paulo@turnpike.com> writes:
>I don't want to get into a discussion of the various merits of different=20
>syntactic meta-languages. ABNF may not be perfect but it has become the=20
>syntactic meta-language of choice for RFCs, it is a proposed standard.=20
>We should use it as is, without extensions. The above is not ABNF.
No, it is not strict ABNF, but it has been in the draft for two, maybe
three, years now, and this is the first time somebody has complained. Does
anybody else on this list want this to be reviewed?
I will grant you that a short explanatory paragraph in section 2.4 would
help, and I will write one.
>If I were to produce an ABNF parser (i.e. one that doesn't understand=20
>your schemas) from your grammar then it could not correctly parse
But does anybody anywhere actually try to parse the ABNF as published (it
would not work in RFC 2822, for example, because the syntax of RFC 2822 is
ambiguous, though not sematically so).
>From: paulo@turnpike.com
>Because without an explicit production for the from header there is=20
>nothing in your syntax to link "From" with from-content. The best it=20
>could do is the general header-content.
Yes, that is a convention inherited from Son-of-1036, and I might well
change it. I think my preferred syntax would now be:
header = <USENET>-header / other-header
<USENET>-header = <USENET>-header-name ":" <USENET>-header-content
*( [CFWS] ";" ( <USENET>-header-parameter /
other-header-parameter ) )
other-header = header-name ":" other-header-content
And then, in the section on the Foo Header:
Foo-header-name = "Foo"
Foo-header-content = ...........
Foo-header-parameter = ............
(except that Foo-header-parameter would be absent except for the few
headers that have them).
-- Charles H. Lindsey ---------At Home, doing my own thing------------------------ Tel: +44 161 436 6131 Fax: +44 161 436 6133 Web: http://www.cs.man.ac.uk/~chl Email: chl@clw.cs.man.ac.uk Snail: 5 Clerewood Ave, CHEADLE, SK8 3JU, U.K. PGP: 2C15F1A9 Fingerprint: 73 6D C2 51 93 A0 01 E7 65 E8 64 7E 14 A4 AB A5