[clug] access control list search algorithms

[jm]

jm wrote:
> Does anyone know of any algorithms for speeding up searching of access 
> control lists? Is there anything more efficient than a sequential search?
>
> Jeff.
>
I should elaborate. I'm mucking about with email trying to develop a 
progrom to give finer control over smtp delivery. My ACL is made up of 
senders and recipients with wildcards thrown in for good measure. For 
example,

index        sender                           recipient    
               action
1              fred at example.org         '*'                             
allow
2              '*'                                  joe at example.org     deny
3             admin at example.org    '*'                               allow


so

  fred at example.org can send to anyone
  admin at example.org can send to everyone, but joe at example.org because it 
is blocked by rule 2
  no-one can send to joe at example.com


At least that's what I'm think of at the moment. if there's a better way 
to accomplish the samething feel free to suggest it as well.

Jeff.