1\DOC assoc 2 3\TYPE {assoc : ''a -> (''a * 'b) list -> 'b} 4 5\SYNOPSIS 6Searches a list of pairs for a pair whose first component equals a 7specified value, then returns the second component of the pair. 8 9\KEYWORDS 10list. 11 12\DESCRIBE 13{assoc x [(x1,y1),...,(xn,yn)]} locates the first {(xi,yi)} in a left-to-right 14scan of the list such that {xi} equals {x}. Then {yi} is returned. The lookup 15is done on an eqtype, i.e., the SML implementation must be able to decide equality 16for the type of {x}. 17 18\FAILURE 19Fails if no matching pair is found. This will always be the case if 20the list is empty. 21 22\EXAMPLE 23{ 24- assoc 2 [(1,4),(3,2),(2,5),(2,6)]; 25> val it = 5 : int 26} 27 28 29\SEEALSO 30Lib.assoc1, Lib.assoc2, Lib.rev_assoc, Lib.mem, Lib.tryfind, Lib.exists, 31Lib.all. 32 33\ENDDOC 34