On Thu, 2022-11-03 at 15:00 -0400, Graydon Saunders wrote:
> Hello --
>
> You can (I think) test if some attribute value is an RFC 4122 UUID by
> using
> a regular expression:
>
> let $regexp as xs:string :=
> '^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-5][0-9a-fA-F]{3}-[089abAB][0-9a-
> fA-F]{3}-[0-9a-fA-F]{12}$'
You could also split this up into strings, maybe using a helper
function:
let $hexdigit := '[0-9a-f]',
$n := function($n as xs:integer) {
$hexdigit || '{' || $n || '}'
},
$matchuuid := '^'
|| $n(8)
|| '-'
|| $n(4)
|| '-'
|| '[0-5]'
|| $n($3)
|| '-'
|| '[098ab]'
|| $n{3}
|| '-'
|| $n{12}
and use it with the case insensitive "i" flag.
However, this isn't very clear.
Mike Kay gives a solution [1],
translate($in, '0123456789abcdefABCDEF', '000000000000000000000000') =
'00000000-0000-0000-0000-000000000000'
which is probably enough in practice.
If you need to check further, see RFC 4122 for the components.
Your regexp limits the UUID value space
https://datatracker.ietf.org/doc/html/rfc4122#page-5
[1] https://p2p.wrox.com/xslt/68464-validate-guid-uuid.html
--
Liam Quin, https://www.delightfulcomputing.com/
Available for XML/Document/Information Architecture/XSLT/
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