loops - collecting multiple maximum values -

i have list of elements. each element structured followed:

('symbol "string" int-score) 

an example list:

(list (list 'object1 "wabadu" 0.5)       (list 'object2 "xezulu" 0.6)       (list 'object1 "yebasi" 0.5)       (list 'object1 "tesora" 0.2)) 

i want retrieve maximum values specific symbol. when search symbol object2, should back:

('object2 "xezulu" 0.6) 

if search object1, should back:

(('object1 "wabadu" 0.5) ('object1 "yebasi" 0.5)) 

i want collect highest elements of specific object. can this: assume above list list used below , i'm searching object1. can retrieve elements of specific object:

(loop element in list      when (equal 'object1 (first element))      collect element) 

i can retrieve 1 highest element of list:

(loop element in list      when (equal 'object1 (first element))      maximize (third element)) 

however, return 1 element. want all maximum elements. i've tried combinations collect , maximize, knowledge on syntax little. there way collect highest elements in ‘simple’ function?

you can looping through list once selecting sublists right first elements , determining maximum (you can use into let loop accumulate multiple values), , second loop in finally clause go through selection , select maximum score:

(loop triple in *l*       (key nil score) = triple       when (eq key 'object1)         collect triple selection         , maximize score max-score       (return (loop triple in selection                             when (eql (third triple) max-score)                               collect triple))) 

edit: alternatively, instead of second loop, delete function can used here quite concisely:

(loop triple in *l*       (key name score) = triple       when (eq key 'object1)         collect triple selection         , maximize score max-score       (return (delete max-score selection                               :test #'/=                               :key #'third)))