else
raise Access ("You aren't a member of group \"" ^ grp ^ "\"")
+fun requireAnyGroupName groups =
+ if List.exists (fn grp => inGroupName grp) groups then
+ ()
+ else
+ raise Access ("You aren't a member of any groups \"" ^ String.concatWith ", " groups ^ "\"")
+
fun validGroupName name =
size name <= 10
andalso CharVector.all Char.isAlphaNum name