Hi,
Leo Prikler <leo.prik...@student.tugraz.at> skribis:
> *gnu/system/shadow.scm (find-duplicates): New variable.
> (assert-unique-account-names, assert-unique-group-names): New variables.
> (account-activation): Use them here.
[...]
> +(define (find-duplicates list =)
> + (match list
> + ('() '())
This should be:
(match list
(() '())
…)
I’m surprised '() works as a pattern.
> + ((first . rest)
> + (if (member first rest =) ; (srfi srfi-1) member
> + (cons first (find-duplicates rest =))
> + (find-duplicates rest =)))))
Note that this is quadratic; it’s fine as long as we don’t have “too
many” users, which may be the case in general.
> +(define (assert-unique-account-names users)
> + (for-each
> + (lambda (account)
> + (raise (condition
> + (&message
> + (message
> + (format #f (G_ "account with name '~a' found twice.")
> + (user-account-name account)))))))
> + (find-duplicates users (lambda (alice bob)
> + (string=? (user-account-name alice)
> + (user-account-name bob))))))
‘for-each’ looks awkward since we’ll stop on the first one. How about
something like:
(define (assert-unique-account-names users)
(match (find-duplicates things …)
(() #t)
(lst
(raise (formatted-message (G_ "the following accounts appear more than
once:~{ ~a~}~%"
lst))))))
?
Thanks!
Ludo’.
