--- /dev/null
+(* Copyright (C) 2000, HELM Team.
+ *
+ * This file is part of HELM, an Hypertextual, Electronic
+ * Library of Mathematics, developed at the Computer Science
+ * Department, University of Bologna, Italy.
+ *
+ * HELM is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * HELM is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HELM; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ *
+ * For details, see the HELM World-Wide-Web page,
+ * http://www.cs.unibo.it/helm/.
+ *)
+
+(* AUTOR: Ferruccio Guidi <fguidi@cs.unibo.it>
+ *)
+
+type path = Avs.path (* the name of an attribute *)
+
+type value = Avs.value (* the value of an attribute *)
+
+type attribute = path * value (* an attribute *)
+
+type group = attribute list (* a group of attributes *)
+
+type attribute_set = group list (* the attributes of an URI *)
+
+type av = string * attribute_set (* an attributed URI *)
+
+type avs = av list (* the query result *)
+
+type peek_t = Empty
+ | Single of (string * group list)
+ | Many of (string * group list)
+
+
+(* constructors *************************************************************)
+
+let grp_empty = []
+
+let grp_make p v = [(p, [v])]
+
+let empty = grp_empty
+
+let make s = function
+ | [] -> [(s, [])]
+ | g -> [(s, [g])]
+
+(* projections **************************************************************)
+
+let subj v = List.rev (List.rev_map (fun x -> (x, [])) v)
+
+let grp_read g p = subj (List.assoc p g)
+
+let single = function
+ | [s, _] -> Some s
+ | _ -> None
+
+(* iterators ****************************************************************)
+
+let rec iter f a = function
+ | [] -> a
+ | [s, _] -> f a s false
+ | (s, _) :: v -> iter f (f a s true) v
+
+let rec x_iter f a = function
+ | [] -> a
+ | [s, gl] -> f a s gl false
+ | (s, gl) :: v -> x_iter f (f a s gl true) v
+
+let rec x_grp_iter f a g = x_iter f a g
+
+(* tests ********************************************************************)
+
+let rec sub v1 v2 =
+ match (v1, v2) with
+ | [], _ -> true
+ | _, [] -> false
+ | (h1, _) :: _, (h2, _) :: _ when h1 < h2 -> false
+ | (h1, _) :: _, (h2, _) :: t2 when h1 > h2 -> sub v1 t2
+ | _ :: t1, _ :: t2 -> sub t1 t2
+
+let rec meet v1 v2 =
+ match v1, v2 with
+ | [], _
+ | _, [] -> false
+ | (h1, _) :: t1, (h2, _) :: _ when h1 < h2 -> meet t1 v2
+ | (h1, _) :: _, (h2, _) :: t2 when h1 > h2 -> meet v1 t2
+ | _, _ -> true
+
+let rec eq v1 v2 =
+ match v1, v2 with
+ | [], [] -> true
+ | (h1, _) :: t1, (h2, _) :: t2 when h1 = h2 -> eq t1 t2
+ | _, _ -> false
+
+(* union ********************************************************************)
+
+let rec set_union v1 v2 =
+ match v1, v2 with
+ | [], v -> v
+ | v, [] -> v
+ | h1 :: t1, h2 :: t2 when h1 < h2 -> h1 :: set_union t1 v2
+ | h1 :: t1, h2 :: t2 when h1 > h2 -> h2 :: set_union v1 t2
+ | h1 :: t1, _ :: t2 -> h1 :: set_union t1 t2
+
+let set_iter f al = List.fold_left (fun s a -> set_union (f a) s) [] al
+
+let grps_make l g = set_union l [g]
+
+let rec union s1 s2 =
+ match s1, s2 with
+ | [], s -> s
+ | s, [] -> s
+ | (r1, g1) :: t1, (r2, _) :: _ when r1 < r2 ->
+ (r1, g1) :: union t1 s2
+ | (r1, _) :: _, (r2, g2) :: t2 when r1 > r2 ->
+ (r2, g2) :: union s1 t2
+ | (r1, g1) :: t1, (_, g2) :: t2 ->
+ (r1, set_union g1 g2) :: union t1 t2
+
+let grp_union = union
+
+let prod g1 g2 =
+ let aux a = set_iter (fun h -> [union a h]) g2 in
+ set_iter aux g1
+
+let rec d_union s1 s2 =
+ match s1, s2 with
+ | [], s -> s
+ | s, [] -> s
+ | (r1, g1) :: t1, (r2, _) :: _ when r1 < r2 ->
+ (r1, g1) :: d_union t1 s2
+ | (r1, _) :: _, (r2, g2) :: t2 when r1 > r2 ->
+ (r2, g2) :: d_union s1 t2
+ | (r1, g1) :: t1, (_, g2) :: t2 ->
+ (r1, prod g1 g2) :: d_union t1 t2
+
+(* intersect ****************************************************************)
+
+let rec set_intersect v1 v2 =
+ match v1, v2 with
+ | [], v -> []
+ | v, [] -> []
+ | h1 :: t1, h2 :: _ when h1 < h2 -> set_intersect t1 v2
+ | h1 :: _, h2 :: t2 when h1 > h2 -> set_intersect v1 t2
+ | h1 :: t1, _ :: t2 -> h1 :: set_intersect t1 t2
+
+let rec intersect s1 s2 =
+ match s1, s2 with
+ | [], s -> []
+ | s, [] -> []
+ | (r1, _) :: t1, (r2, _) :: _ when r1 < r2 -> intersect t1 s2
+ | (r1, _) :: _, (r2, _) :: t2 when r1 > r2 -> intersect s1 t2
+ | (r1, g1) :: t1, (_, g2) :: t2 ->
+ (r1, set_intersect g1 g2) :: intersect t1 t2
+
+(* diff *********************************************************************)
+
+let rec diff s1 s2 =
+ match s1, s2 with
+ | [], _ -> []
+ | s, [] -> s
+ | (r1, g1) :: t1 , (r2, _) ::_ when r1 < r2 ->
+ (r1, g1) :: (diff t1 s2)
+ | (r1, _) :: _, (r2, _) :: t2 when r1 > r2 -> diff s1 t2
+ | _ :: t1, _ :: t2 -> diff t1 t2
+
+(* concatenation ************************************************************)
+
+let append v1 v2 = v1 @ v2
+
+(* peeking ******************************************************************)
+
+let peek = function
+ | [] -> Empty
+ | [s, gl] -> Single (s, gl)
+ | (s, gl) :: _ -> Many (s, gl)
projects / helm.git / blobdiff