Merged from branch stable-succint-refactor

[SXSI/xpathcomp.git] / ptset.ml

diff --git a/ptset.ml b/ptset.ml
index 5c029f7..091d4a8 100644 (file)
--- a/ptset.ml
+++ b/ptset.ml
@@ -38,8 +38,14 @@ module Node =
       | _ -> false
   end
 
-module WH = Weak.Make(Node)
-
+module WH =Weak.Make(Node) 
+(* struct 
+  include Hashtbl.Make(Node)
+    let merge h v =
+      if mem h v then v
+      else (add h v v;v)
+end
+*)
 let pool = WH.create 4093
 
 (* Neat trick thanks to Alain Frisch ! *)
@@ -63,14 +69,14 @@ let rec norm n =
 
 (*  WH.merge pool *)
 
-let branch (p,m,l,r) = norm (Branch(p,m,l,r))
+let branch  p m l r  = norm (Branch(p,m,l,r))
 let leaf k = norm (Leaf k)
 
 (* To enforce the invariant that a branch contains two non empty sub-trees *)
 let branch_ne = function
   | (_,_,e,t) when is_empty e -> t
   | (_,_,t,e) when is_empty e -> t
-  | (p,m,t0,t1)   -> branch (p,m,t0,t1)
+  | (p,m,t0,t1)   -> branch p m t0 t1
 
 (********** from here on, only use the smart constructors *************)
 
@@ -113,10 +119,10 @@ let rec min_elt n = match n.node with
   let hbit = Array.init 256 naive_highest_bit
   
   let highest_bit_32 x =
-    let n = x lsr 24 in if n != 0 then hbit.(n) lsl 24
-    else let n = x lsr 16 in if n != 0 then hbit.(n) lsl 16
-    else let n = x lsr 8 in if n != 0 then hbit.(n) lsl 8
-    else hbit.(x)
+    let n = x lsr 24 in if n != 0 then Array.unsafe_get hbit n lsl 24
+    else let n = x lsr 16 in if n != 0 then Array.unsafe_get hbit n lsl 16
+    else let n = x lsr 8 in if n != 0 then Array.unsafe_get hbit n lsl 8
+    else Array.unsafe_get hbit x
 
   let highest_bit_64 x =
     let n = x lsr 32 in if n != 0 then (highest_bit_32 n) lsl 32
@@ -129,27 +135,27 @@ let rec min_elt n = match n.node with
 
   let branching_bit p0 p1 = highest_bit (p0 lxor p1)
 
-  let join (p0,t0,p1,t1) =  
+  let join p0 t0 p1 t1 =  
     let m = branching_bit p0 p1  in
     if zero_bit p0 m then 
-      branch (mask p0 m, m, t0, t1)
+      branch (mask p0 m)  m t0 t1
     else 
-      branch (mask p0 m, m, t1, t0)
+      branch (mask p0 m) m t1 t0
     
   let match_prefix k p m = (mask k m) == p
 
   let add k t =
     let rec ins n = match n.node with
       | Empty -> leaf k
-      | Leaf j ->  if j == k then n else join (k, leaf k, j, n)
+      | Leaf j ->  if j == k then n else join k (leaf k) j n
       | Branch (p,m,t0,t1)  ->
          if match_prefix k p m then
            if zero_bit k m then 
-             branch (p, m, ins t0, t1)
+             branch p m (ins t0) t1
            else
-             branch (p, m, t0, ins t1)
+             branch p m t0 (ins t1)
          else
-           join (k, leaf k, p, n)
+           join k  (leaf k)  p n
     in
     ins t
       
@@ -170,12 +176,12 @@ let rec min_elt n = match n.node with
       
   (* should run in O(1) thanks to Hash consing *)
 
-  let equal = (=)
+  let equal a b = a==b || a.id == b.id
 
-  let compare = compare
+  let compare a b = if a == b then 0 else a.id - b.id
 
 
-  let rec merge (s,t)  = 
+  let rec merge s t = 
     if (equal s t) (* This is cheap thanks to hash-consing *)
     then s
     else
@@ -186,23 +192,22 @@ let rec min_elt n = match n.node with
        | _, Leaf k -> add k s
        | Branch (p,m,s0,s1), Branch (q,n,t0,t1) ->
            if m == n && match_prefix q p m then
-             branch (p, m, merge (s0,t0), merge (s1,t1))
+             branch p  m  (merge s0 t0) (merge s1 t1)
            else if m > n && match_prefix q p m then
              if zero_bit q m then 
-               branch (p, m, merge (s0,t), s1)
+               branch p m (merge s0 t) s1
               else 
-               branch (p, m, s0, merge (s1,t))
-           else if m < n && match_prefix p q n then
-             
+               branch p m s0 (merge s1 t)
+           else if m < n && match_prefix p q n then     
              if zero_bit p n then
-               branch (q, n, merge (s,t0), t1)
+               branch q n (merge s t0) t1
              else
-               branch (q, n, t0, merge (s,t1))
+               branch q n t0 (merge s t1)
            else
              (* The prefixes disagree. *)
-             join (p, s, q, t)
+             join p s q t
            
-  let union s t = merge (s,t)
+
 
   let rec subset s1 s2 = (equal s1 s2) ||
     match (s1.node,s2.node) with
@@ -220,9 +225,12 @@ let rec min_elt n = match n.node with
              subset l1 r2 && subset r1 r2
          else
            false
+
+  let union s t = 
+      merge s t
              
   let rec inter s1 s2 = 
-    if (equal s1 s2) 
+    if equal s1 s2 
     then s1
     else
       match (s1.node,s2.node) with
@@ -232,7 +240,7 @@ let rec min_elt n = match n.node with
        | _, Leaf k2 -> if mem k2 s1 then s2 else empty
        | Branch (p1,m1,l1,r1), Branch (p2,m2,l2,r2) ->
            if m1 == m2 && p1 == p2 then 
-             merge (inter l1 l2, inter r1 r2)
+             merge (inter l1 l2)  (inter r1 r2)
            else if m1 > m2 && match_prefix p2 p1 m1 then
              inter (if zero_bit p2 m1 then l1 else r1) s2
            else if m1 < m2 && match_prefix p1 p2 m2 then
@@ -241,7 +249,7 @@ let rec min_elt n = match n.node with
              empty
 
   let rec diff s1 s2 = 
-    if (equal s1 s2) 
+    if equal s1 s2 
     then empty
     else
       match (s1.node,s2.node) with
@@ -251,12 +259,12 @@ let rec min_elt n = match n.node with
        | _, Leaf k2 -> remove k2 s1
        | Branch (p1,m1,l1,r1), Branch (p2,m2,l2,r2) ->
            if m1 == m2 && p1 == p2 then
-             merge (diff l1 l2, diff r1 r2)
+             merge (diff l1 l2) (diff r1 r2)
            else if m1 > m2 && match_prefix p2 p1 m1 then
              if zero_bit p2 m1 then 
-               merge (diff l1 s2, r1) 
+               merge (diff l1 s2) r1
              else 
-               merge (l1, diff r1 s2)
+               merge l1 (diff r1 s2)
            else if m1 < m2 && match_prefix p1 p2 m2 then
              if zero_bit p1 m2 then diff s1 l2 else diff s1 r2
            else