+let rec rm_assoc n = function
+ | [] -> assert false
+ | (x,i)::tl when n=x -> i,tl
+ | p::tl -> let i,tl = rm_assoc n tl in i,p::tl
+;;
+
+let merge canonicals elements n m =
+ let cn,canonicals = rm_assoc n canonicals in
+ let cm,canonicals = rm_assoc m canonicals in
+ let ln,elements = rm_assoc cn elements in
+ let lm,elements = rm_assoc cm elements in
+ let canonicals =
+ (n,cm)::(m,cm)::List.map
+ (fun (x,xc) as p ->
+ if xc = cn then (x,cm) else p) canonicals
+ in
+ let elements = (cn,ln@lm)::elements
+ in
+ canonicals,elements
+;;
+
+let clusters f l =
+ let canonicals = List.map (fun x -> (x,x)) l in
+ let elements = List.map (fun x -> (x,[x])) l in
+ List.fold_left
+ (fun (canonicals,elements) x ->
+ let dep = f x in
+ List.fold_left
+ (fun (canonicals,elements) d ->
+ merge canonicals elements d x)
+ (canonicals,elements) dep)
+ (canonicals,elements) l
+;;
+