Initial revision

[helm.git] / helm / ocaml / mathql_interpreter / union.ml

diff --git a/helm/ocaml/mathql_interpreter/union.ml b/helm/ocaml/mathql_interpreter/union.ml
index c8e46cd0b8ee991c8f324c6b99b4464f67514d0f..e2d9fcb01a7e75be68bc141783eca03ccb1423bf 100644 (file)
--- a/helm/ocaml/mathql_interpreter/union.ml
+++ b/helm/ocaml/mathql_interpreter/union.ml
@@ -27,113 +27,26 @@
  * implementazione del comando UNION
  *)
 
-(*
-(*
- * 
- *)
-let xres_fill_context hr h1 l1 =
- match l1 with
-    [] -> []
- |   _ ->
-     let hh = List.combine h1 l1
-     in
-      List.map
-       (fun x ->
-        if (List.mem_assoc x hh) then
-        List.assoc x hh
-       else
-        ""
-       )
-       hr
-;;
 
-(*
- * implementazione del comando UNION
- *)
-let union_ex alist1 alist2 =
- let head1 = List.hd alist1
- and tail1 = List.tl alist1
- and head2 = List.hd alist2
- and tail2 = List.tl alist2 (* e fin qui ... *)
- in
-  match (head1, head2) with
-     ([], _) -> assert false (* gli header non devono mai essere vuoti *)
-  |  (_, []) -> assert false (* devono contenere almeno [retVal] *)
-  |  (_,  _) -> let headr = (head2 @
-                            (List.find_all
-                            (function t -> not (List.mem t head2))
-                            head1)
-                           ) in (* header del risultato finale *)
-      List.append (* il risultato finale e' la concatenazione ...*)
-       [headr]             (* ... dell'header costruito prima ...*)
-       (Sort.list
-        (fun l m -> List.hd l < List.hd m)
-        (match (tail1, tail2) with      (* e di una coda "unione" *)
-            ([], _) -> tail2 (* va bene perche' l'altra lista e' vuota *)
-         |  (_, []) -> tail1 (* va bene perche' l'altra lista e' vuota *)
-         |  (_,  _) ->
-            let first = (* parte dell'unione che riguarda solo il primo set *)
-             List.map
-              (
-               fun l ->
-                [List.hd l] @
-                xres_fill_context (List.tl headr) (List.tl head1) (List.tl l)
-              )
-              tail1
-             in
-             List.fold_left
-              (fun par x ->
-               let y = (* elemento candidato ad entrare *)
-                [List.hd x]
-                @
-                xres_fill_context
-                 (List.tl headr) (List.tl head2) (List.tl x)
-               in
-                par @ if (List.find_all (fun t -> t = y) par) = [] then
-                       [y]
-                      else
-                       []
-              )
-              first (* List.fold_left *)
-              tail2 (* List.fold_left *)
-(*          first @
-            List.map (fun l -> [List.hd l] @
-                      xres_fill_context
-                       (List.tl headr) (List.tl head2) (List.tl l)
-                     ) tail2
-*)
-        ) (* match *)
-       )
-;;
-*)
+(* Merges two attribute group lists preserves order and gets rid of duplicates*)
+let rec merge l1 l2 =
+  match (l1,l2) with
+     [],l
+   | l,[] -> l
+   | g1::tl1,g2::_ when g1 < g2 -> g1::(merge tl1 l2)
+   | g1::_,g2::tl2 when g2 < g1 -> g2::(merge l1 tl2)
+   | g1::tl1,g2::tl2 -> g1::(merge tl1 tl2)
+;;       
 
 (* preserves order and gets rid of duplicates *)
-let rec union_ex l1 l2 =
- let module S = Mathql_semantics in
-  match (l1, l2) with
+let rec union_ex rs1 rs2 =
+  match (rs1, rs2) with
      [],l
    | l,[] -> l
-   | ({S.uri = uri1} as entry1)::tl1,
-     ({S.uri = uri2} as entry2)::_ when uri1 < uri2 ->
-       entry1::(union_ex tl1 l2)
-   | ({S.uri = uri1} as entry1)::_,
-     ({S.uri = uri2} as entry2)::tl2 when uri2 < uri1 ->
-       entry2::(union_ex l1 tl2)
-   | entry1::tl1,entry2::tl2 -> (* same entry *)
-      if entry1 = entry2 then (* same attributes *)
-       entry1::(union_ex tl1 tl2)
-      else
-       assert false
+   | (uri1,l1)::tl1,(uri2,_)::_ when uri1 < uri2 -> (uri1,l1)::(union_ex tl1 rs2)
+   | (uri1,_)::_,(uri2,l2)::tl2 when uri2 < uri1 -> (uri2,l2)::(union_ex rs1 tl2)
+   | (uri1,l1)::tl1,(uri2,l2)::tl2 -> if l1 = l2 then (uri1,l1)::(union_ex tl1 tl2)
+                                     else (uri1,merge l1 l2)::(union_ex tl1 tl2)       
 ;;
 
-let union_ex l1 l2 =
- let before = Unix.time () in
- let res = union_ex l1 l2 in
- let after = Unix.time () in
-  let ll1 = string_of_int (List.length l1) in
-  let ll2 = string_of_int (List.length l2) in
-  let diff = string_of_float (after -. before) in
-  print_endline ("UNION(" ^ ll1 ^ "," ^ ll2 ^ "): " ^ diff ^ "s") ;
-  flush stdout ;
-  res
-;;
+