1) ecrire la fonction hash et equal

[tatoo.git] / src / table.ml

diff --git a/src/table.ml b/src/table.ml
index ae446ea..f0e24ee 100644 (file)
--- a/src/table.ml
+++ b/src/table.ml
@@ -5,21 +5,56 @@ type move = Self
            | Revfirstchild
            | Prevsibling
 
-type query_tree = Binop of op * query_tree * query_tree
-                 | Axis of Xpath.Ast.axis * query_tree
-                 | Start 
-                 | Dom
-                 | Tag of QNameSet.t * Tree.NodeKind.t
+type query_tree_desc = Binop of op * query_tree * query_tree
+                      | Axis of Xpath.Ast.axis * query_tree
+                      | Start 
+                      | Dom
+                      | Tag of QNameSet.t * Tree.NodeKind.t
+
 and op = Union | Inter | Diff
-(*and query_tree = {
+
+and query_tree = {
   mutable desc  : query_tree_desc;
   mutable id : int;
   mutable hash : int;
 }
-*)
-
 
 
+module QTree = struct
+  type t = query_tree
+  let rec equal q1 q2 =
+    q1 == q2 ||
+      (q1.id == q2.id && q1.id != -1) ||
+      match q1.desc, q2.desc with
+       | Binop(op1,qt1,qt2),Binop(op2,qt3,qt4)-> op1==op2&& (equal qt1 qt3 && equal qt2 qt4) 
+                                                          
+       | Axis(a1,qt1),Axis(a2,qt2) -> compare_axis a1 a2 && equal qt1 qt2
+       | Tag(t1,k1),Tag(t2,k2) -> t1==t2&& k1==k2
+       | Dom,Dom | Start,Start -> true
+       | _,_ ->false
+  and compare_axis a1 a2 =
+    match a1,a2 with
+       Self ,Self | Attribute, Attribute | Child , Child | Parent , Parent
+      | FollowingSibling , FollowingSibling       
+      | PrecedingSibling , PrecedingSibling
+      | Preceding , Preceding | Following , Following -> true
+      | Descendant b1, Descendant b2 -> b1==b2 
+      | Ancestor b1, Ancestor b2 -> b1==b2
+      | _,_ -> false
+
+  let rec hash q = 
+    if q.hash != -1 then q.hash
+    else match q.desc with
+       Dom -> 1
+      | Start -> 3
+      | Tag(s,_) -> 5 + 17*QNameSet.hash s
+      | Axis(a,q) -> 7 + 17 * Hashtbl.hash a + 23* hash q
+      | Binop(op,q1,q2) -> 11 + 17* Hashtbl.hash op + 23* hash q1 + 27* hash q2
+
+end
+
+
+module QTreeHash = Hashtbl.Make(QTree)
 
 
 
@@ -37,7 +72,7 @@ let print_node_list tree l =
   ) l
 
 let rec print_query_tree fmt q =
-  match q with
+  match q.desc with
       Dom -> Format.fprintf fmt "Dom"
     | Start -> Format.fprintf fmt "Start"
     | Tag (t,k) -> Format.fprintf fmt "Tag(%a, %a)" QNameSet.print t Tree.NodeKind.print k