assoc
hol88Lib.assoc : ''a -> (''a * 'b) list -> ''a * 'b
Searches a list of pairs for a pair whose first component equals a specified value.
assoc x [(x1,y1),...,(xn,yn)] returns the first (xi,yi) in the list
such that xi equals x. The lookup is done on an eqtype, i.e., the
SML implementation must be able to decide equality for the type of x.
Failure
Fails if no matching pair is found. This will always be the case if the list is empty.
Example
- assoc 2 [(1,4),(3,2),(2,5),(2,6)];
(2, 5) : (int * int)
Comments
Superseded by Lib.assoc and Lib.assoc1.