Subject: ABNF for field-value

From: Adrian Custer <[email-masked]>
Date: Sun, 02 Sep 2012 11:02:31 -0400

Hey all,

Section 3.2.2 of version 20 of the current draft, in the second 
paragraph, states:
   "The field value does not include any leading or
    trailing white space: ..."
so should the ABNF not be something like

field-value = (VCHAR / obs-text) [ *(field-content / obs-fold)
                                    (VCHAR / obs-text) ]

(ignoring the line break which may alter the semantic meaning)?

The current ABNF allows both leading and trailing whitespace, indeed 
would allow the whole value to be a space.

Since this definition would force the field-value to be non-empty, this 
approach would require allowing the field-value to be optional in the 
<header-field> element rather than requiring a, possibly empty, 
field-value. That approach makes more logical sense to me but might have 
repercussions of which I am unaware.

cheers,
   Adrian

---

From: Julian Reschke <[email-masked]>
Date: Thu, 06 Sep 2012 11:05:23 +0200

On 2012-09-02 17:02, Adrian Custer wrote:
> ...

As far as I can tell, this would work, too, but I'm not sure it's an 
improvement.

At the end of the day, the ABNF definitions do not tell you all you need 
to know, so there's also value in keeping them readable.

Best regards, Julian