Subject: [Ltru] At most one star is enough

From: Frank Ellermann <[email-masked]>
Date: Fri, 10 Feb 2006 06:14:28 +0100

Hi, there's one special case where "at most one" (leading or
lone) "star is enough" might be _not_ enough, and that's if
a future extension registry has its own concept of wildcards.
For that we could do the following (proposed ABNF plus prose):

| language-range  = langtag-range
|                 / privateuse
|                 / grandfathered

| langtag-range   = (( language / "*" )
|                    ["-" script]
|                    ["-" region]
|                    *("-" variant)
|                    *("-" extension-range)
|                    ["-" privateuse])

| extension-range = extension
|                 / ( singleton 1*( "-" ( 2*8alphanum / "*" )))

| A <language-range> without wildcard <extension-range> either
| starts with a <language> or a "*", and all other productions
| follow the syntax defined in [RFC3066bis].  All unspecified
| subtags after the <language> or "*" match any possible value.
| for that subtag.  A leading or lone "*" matches any possible
| <language>.

| Documents defining extension registries MAY introduce their
| own concept of an <extension-range> employing a "*".  These
| <extension-range>s are always introduced by a <singleton>
| ending before the next <singleton> or at the end of the
| <language-range>, and therefore it's always clear to which
| <extension-range> an embedded "*" syntactically belongs.

                                Bye, Frank

_______________________________________________
Ltru mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/ltru