Re: ACTION-2130: Summarise the apache email validation

OK, Erik's email led me back to RFC 5321:
https://tools.ietf.org/html/rfc5321

Somewhere deep in that document, you find the definition for mailbox:

 Mailbox        = Local-part "@" ( Domain / address-literal )

Address literals are for IP addresses. I propose we drop those.

 Domain         = sub-domain *("." sub-domain)

I propose we require at least one "."

 sub-domain     = Let-dig [Ldh-str]
 Let-dig        = ALPHA / DIGIT
 Ldh-str        = *( ALPHA / DIGIT / "-" ) Let-dig

So a sub-domain must start and end with a letter or digit, and may contain  
hyphens.

 Local-part     = Dot-string / Quoted-string

I propose we drop quoted-string.

 Dot-string     = Atom *("."  Atom)
 Atom           = 1*atext

So a local part consists of one or more atoms separated by ".".
An atom is a string of 1 or more atexts.

You have to go to RFC 5322 to find the definition of atext:
https://tools.ietf.org/html/rfc5322

 atext           =   ALPHA / DIGIT /    ; Printable US-ASCII
                        "!" / "#" /        ;  characters not including
                        "$" / "%" /        ;  specials.  Used for atoms.
                        "&" / "'" /
                        "*" / "+" /
                        "-" / "/" /
                        "=" / "?" /
                        "^" / "_" /
                        "`" / "{" /
                        "|" / "}" /
                        "~"
I propose we keep those.

So in summary:

   email: atom ("." atom)* "@" sub ("." sub)+

   sub: letdig (ldh* letdig)?
   letdig: a-Z A-Z 0-9
   ldh: letdig | "-"
   atom: atext+

Steven

On Wed, 28 Jun 2017 15:15:47 +0200, XForms Users Community Group Issue  
Tracker <sysbot+tracker@w3.org> wrote:

> ACTION-2130: Summarise the apache email validation
>
> https://www.w3.org/2005/06/tracker/xforms/actions/2130
>
> Assigned to: Steven Pemberton
>
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>
>
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Received on Wednesday, 28 June 2017 16:12:22 UTC