Creating a unique list from a bunch of duplicates

[J . Davison de St . Germain]

Hi,

  I need to be able to take a list of directories and remove the 
duplicates without sorting the list.  For example, if I have 
"-L/abc/lib -L/def/lib -L/abc/lib" I would like to get back "-L/abc/lib 
-L/def/lib".  I would like to do this within make so that I don't have 
to call a bunch of shell functions.  I've talked to a number of other 
gmake makefile writers and they agree that this would be very helpful.  
Is there such a function in make?  (Like $(unique list) or some such?)  
If not, has someone well versed in functional programming put together 
a bunch of filter/foreach/search/etc functions to do this?  Any help on 
this would be greatly appreciated.  Also, if you know of a better 
location to send this request to, please let me know.

    Sincerely,
              J. Davison de St. Germain

PS.  My search of the mailing list archive only gave me one hit and 
that was to use sort.  As I mention above, I need the list to stay in 
the same order.  Thanks!

-----------------------------------------------------------------------
- J. Davison de St. Germain         address@hidden    (801) 581-4078 -
- Chief Software Engineer           http://www.cs.utah.edu/~dav       -
- SCI Institute, SE C-SAFE          University of Utah                -
-----------------------------------------------------------------------