match gr1, gr2 with
[],_ -> gr2
| _,[] -> gr1
+ | gr1, gr2 when gr1 = gr2 -> gr1
| (key1,l1)::tl1, (key2,l2)::_ when key1 < key2 -> (key1,l1)::(sum_groups (tl1,gr2))
| (key1,l1)::_, (key2,l2)::tl2 when key2 < key1 -> (key2,l2)::(sum_groups (gr1,tl2))
| (key1,l1)::tl1, (key2,l2)::tl2 -> (key1,(append (l1,l2)))::(sum_groups (tl1,tl2))
;;
(* Product between an attribute set and a group of attributes *)
-let rec sub_prod (aset, gr) = (*prende un aset e un gr e fa la somma tra tutti i gruppi di aset e gr *)
+let rec sub_prod (aset, gr) = (*prende un aset e un gr, fa la somma tra tutti i gruppi di aset e gr*)
match aset with
[] -> []
| gr1::tl1 -> sum_groups (gr1, gr)::(sub_prod(tl1, gr))
(* Cartesian product between two attribute sets*)
let rec prod (as1, as2) =
match as1, as2 with
- [],_ -> as2
- | _,[] -> as1
- | gr1::tl1, _ -> (sub_prod (as2, gr1))@(prod (tl1, as2)) (* chiamo la sub_prod con un el. as1 e as2 *)
+ [],_ -> []
+ | _,[] -> []
+ | gr1::tl1, _ -> append((sub_prod (as2, gr1)), (prod (tl1, as2))) (* chiamo la sub_prod con un el. as1 e as2 *)
;;
(* Intersection between two resource sets, preserves order and gets rid of duplicates *)
-let intersect_ex rs1 rs2 =
- let rec intersect_aux rs1 rs2 =
- match (rs1, rs2) with
- [],_
- | _,[] -> []
- | (uri1,_)::tl1,
- (uri2,_)::_ when uri1 < uri2 -> intersect_aux tl1 rs2
- | (uri1,_)::_,
- (uri2,_)::tl2 when uri2 < uri1 -> intersect_aux rs1 tl2
- | (uri1,as1)::tl1,
- (uri2,as2)::tl2 -> (uri1, prod(as1,as2))::intersect_aux tl1 tl2
- in
- let before = Sys.time () in
- let res = intersect_aux rs1 rs2 in
- let after = Sys.time () in
- let ll1 = string_of_int (List.length rs1) in
- let ll2 = string_of_int (List.length rs2) in
- let diff = string_of_float (after -. before) in
- print_endline
- ("INTERSECT(" ^ ll1 ^ "," ^ ll2 ^ ") = " ^ string_of_int (List.length res) ^
- ": " ^ diff ^ "s") ;
- flush stdout ;
- res
+let rec intersect_ex rs1 rs2 =
+ match (rs1, rs2) with
+ [],_
+ | _,[] -> []
+ | (uri1,_)::tl1, (uri2,_)::_ when uri1 < uri2 -> intersect_ex tl1 rs2
+ | (uri1,_)::_, (uri2,_)::tl2 when uri2 < uri1 -> intersect_ex rs1 tl2
+ | (uri1,as1)::tl1, (uri2,as2)::tl2 -> (uri1, prod(as1,as2))::intersect_ex tl1 tl2
;;
-