From: Kim Nguyễn <kn@lri.fr>
Date: Fri, 26 Oct 2012 15:38:57 +0000 (+0200)
Subject: Cosmetic changes in the Patricia Tree code.
X-Git-Tag: v0.1~199
X-Git-Url: http://git.nguyen.vg/gitweb/?p=tatoo.git;a=commitdiff_plain;h=a5677f6cf1ad13dcb9a0c8a8879eeec8e9162363

Cosmetic changes in the Patricia Tree code.
---

diff --git a/src/ptset.ml b/src/ptset.ml
index af046a8..774b9fc 100644
--- a/src/ptset.ml
+++ b/src/ptset.ml
@@ -1,5 +1,4 @@
-(* Original file : *)
-
+(* Original file: *)
 (***********************************************************************)
 (*                                                                     *)
 (*  Copyright (C) Jean-Christophe Filliatre                            *)
@@ -16,11 +15,11 @@
 (***********************************************************************)
 
 (* Modified by Kim Nguyen *)
-(* The Patricia trees are themselves deeply hashconsed. The module
-   provides a Make (and Weak) functor to build hashconsed patricia
-   trees whose elements are Abstract hashconsed values. This allows
-   to build sets of integers without boxing them in an hacons structure
+(* The Patricia trees are themselves deeply hash-consed. The module
+   provides a Make (and Weak) functor to build hash-consed patricia
+   trees whose elements are Abstract hash-consed values.
 *)
+
 INCLUDE "utils.ml"
 
 include Sigs.PTSET
@@ -39,22 +38,22 @@ struct
     | Branch of int * int * 'a * 'a
 
   module rec Node : Hcons.S with type data = Data.t = HCB(Data)
-  and Data : Sigs.AUX.HashedType with type t = Node.t set =
+                            and Data : Sigs.AUX.HashedType with type t = Node.t set =
   struct
     type t =  Node.t set
     let equal x y =
       match x,y with
-        Empty,Empty -> true
+      | Empty,Empty -> true
       | Leaf k1, Leaf k2 ->  k1 == k2
-      | Branch(b1,i1,l1,r1),Branch(b2,i2,l2,r2) ->
-        b1 == b2 && i1 == i2 && (Node.equal l1 l2) && (Node.equal r1 r2)
+      | Branch(b1,i1,l1,r1), Branch(b2,i2,l2,r2) ->
+          b1 == b2 && i1 == i2 && (Node.equal l1 l2) && (Node.equal r1 r2)
 
       | _ -> false
 
     let hash = function
-      | Empty -> 0
-      | Leaf i -> HASHINT2 (PRIME1, Uid.to_int (H.uid i))
-      | Branch (b,i,l,r) ->
+    | Empty -> 0
+    | Leaf i -> HASHINT2 (PRIME1, Uid.to_int (H.uid i))
+    | Branch (b,i,l,r) ->
         HASHINT4(b, i, Uid.to_int l.Node.id, Uid.to_int r.Node.id)
   end
 
@@ -68,13 +67,13 @@ struct
 
   let leaf k = Node.make (Leaf k)
 
-  (* To enforce the invariant that a branch contains two non empty
-     sub-trees *)
+                            (* To enforce the invariant that a branch contains two non empty
+                               sub-trees *)
   let branch_ne p m t0 t1 =
     if (is_empty t0) then t1
     else if is_empty t1 then t0 else branch p m t0 t1
 
-  (******** from here on, only use the smart constructors ************)
+                            (******** from here on, only use the smart constructors ************)
 
   let zero_bit k m = (k land m) == 0
 
@@ -82,33 +81,33 @@ struct
 
   let is_singleton n =
     match Node.node n with Leaf _ -> true
-      | _ -> false
+    | _ -> false
 
   let mem (k:elt) n =
     let kid = Uid.to_int (H.uid k) in
     let rec loop n = match Node.node n with
-      | Empty -> false
-      | Leaf j ->  k == j
-      | Branch (p, _, l, r) -> if kid <= p then loop l else loop r
+    | Empty -> false
+    | Leaf j ->  k == j
+    | Branch (p, _, l, r) -> if kid <= p then loop l else loop r
     in loop n
 
   let rec min_elt n = match Node.node n with
-    | Empty -> raise Not_found
-    | Leaf k -> k
-    | Branch (_,_,s,_) -> min_elt s
+  | Empty -> raise Not_found
+  | Leaf k -> k
+  | Branch (_,_,s,_) -> min_elt s
 
   let rec max_elt n = match Node.node n with
-    | Empty -> raise Not_found
-    | Leaf k -> k
-    | Branch (_,_,_,t) -> max_elt t
+  | Empty -> raise Not_found
+  | Leaf k -> k
+  | Branch (_,_,_,t) -> max_elt t
 
   let elements s =
     let rec elements_aux acc n = match Node.node n with
-      | Empty -> acc
-      | Leaf k -> k :: acc
-      | Branch (_,_,l,r) -> elements_aux (elements_aux acc r) l
+    | Empty -> acc
+    | Leaf k -> k :: acc
+    | Branch (_,_,l,r) -> elements_aux (elements_aux acc r) l
     in
-      elements_aux [] s
+    elements_aux [] s
 
   let mask k m  = (k lor (m-1)) land (lnot m)
 
@@ -117,20 +116,20 @@ struct
     let rec loop i =
       if i = 0 then 1 else if x lsr i = 1 then 1 lsl i else loop (i-1)
     in
-      loop 7
+    loop 7
 
   let hbit = Array.init 256 naive_highest_bit
-(*
-  external clz : int -> int = "caml_clz" "noalloc"
-  external leading_bit : int -> int = "caml_leading_bit" "noalloc"
-*)
+                            (*
+                              external clz : int -> int = "caml_clz" "noalloc"
+                              external leading_bit : int -> int = "caml_leading_bit" "noalloc"
+                            *)
   let highest_bit x =
     try
       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)
+        else let n = (x) lsr 8 in if n != 0 then hbit.(n) lsl 8
+          else hbit.(x)
     with
       _ -> raise (Invalid_argument ("highest_bit " ^ (string_of_int x)))
 
@@ -143,47 +142,47 @@ struct
   let join p0 t0 p1 t1 =
     let m = branching_bit p0 p1  in
     let msk = mask p0 m in
-      if zero_bit p0 m then
-        branch_ne msk m t0 t1
-      else
-        branch_ne msk m t1 t0
+    if zero_bit p0 m then
+    branch_ne msk m t0 t1
+    else
+    branch_ne msk m t1 t0
 
   let match_prefix k p m = (mask k m) == p
 
   let add k t =
     let kid = Uid.to_int (H.uid k) in
-      assert (kid >=0);
+    assert (kid >=0);
     let rec ins n = match Node.node n with
-      | Empty -> leaf k
-      | Leaf j ->  if j == k then n else join kid (leaf k) (Uid.to_int (H.uid j)) n
-      | Branch (p,m,t0,t1)  ->
+    | Empty -> leaf k
+    | Leaf j ->  if j == k then n else join kid (leaf k) (Uid.to_int (H.uid j)) n
+    | Branch (p,m,t0,t1)  ->
         if match_prefix kid p m then
-          if zero_bit kid m then
-            branch_ne p m (ins t0) t1
-          else
-            branch_ne p m t0 (ins t1)
+        if zero_bit kid m then
+        branch_ne p m (ins t0) t1
         else
-          join kid (leaf k)  p n
+        branch_ne p m t0 (ins t1)
+        else
+        join kid (leaf k)  p n
     in
     ins t
 
   let remove k t =
     let kid = Uid.to_int(H.uid k) in
     let rec rmv n = match Node.node n with
-      | Empty -> empty
-      | Leaf j  -> if  k == j then empty else n
-      | Branch (p,m,t0,t1) ->
+    | Empty -> empty
+    | Leaf j  -> if  k == j then empty else n
+    | Branch (p,m,t0,t1) ->
         if match_prefix kid p m then
-          if zero_bit kid m then
-            branch_ne p m (rmv t0) t1
-          else
-            branch_ne p m t0 (rmv t1)
+        if zero_bit kid m then
+        branch_ne p m (rmv t0) t1
+        else
+        branch_ne p m t0 (rmv t1)
         else
-          n
+        n
     in
     rmv t
 
-  (* should run in O(1) thanks to Hash consing *)
+                            (* should run in O(1) thanks to Hash consing *)
 
   let equal a b = Node.equal a b
 
@@ -194,170 +193,170 @@ struct
     then s
     else
     match Node.node s, Node.node t with
-      | Empty, _  -> t
-      | _, Empty  -> s
-      | Leaf k, _ -> add k t
-      | _, Leaf k -> add k s
-      | Branch (p,m,s0,s1), Branch (q,n,t0,t1) ->
+    | Empty, _  -> t
+    | _, Empty  -> s
+    | Leaf k, _ -> add k t
+    | _, 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_ne p m (merge s0 t) s1
-          else
-            branch_ne p m s0 (merge s1 t)
+        if zero_bit q m then
+        branch_ne p m (merge s0 t) s1
+        else
+        branch_ne p m s0 (merge s1 t)
         else if m < n && match_prefix p q n then
-          if zero_bit p n then
-            branch_ne q n (merge s t0) t1
-          else
-            branch_ne q n t0 (merge s t1)
+        if zero_bit p n then
+        branch_ne q n (merge s t0) t1
+        else
+        branch_ne q n t0 (merge s t1)
         else
-          (* The prefixes disagree. *)
-          join p s q t
+                                  (* The prefixes disagree. *)
+        join p s q t
 
 
 
 
   let rec subset s1 s2 = (equal s1 s2) ||
     match (Node.node s1,Node.node s2) with
-      | Empty, _ -> true
-      | _, Empty -> false
-      | Leaf k1, _ -> mem k1 s2
-      | Branch _, Leaf _ -> false
-      | Branch (p1,m1,l1,r1), Branch (p2,m2,l2,r2) ->
+    | Empty, _ -> true
+    | _, Empty -> false
+    | Leaf k1, _ -> mem k1 s2
+    | Branch _, Leaf _ -> false
+    | Branch (p1,m1,l1,r1), Branch (p2,m2,l2,r2) ->
         if m1 == m2 && p1 == p2 then
-          subset l1 l2 && subset r1 r2
+        subset l1 l2 && subset r1 r2
         else if m1 < m2 && match_prefix p1 p2 m2 then
-          if zero_bit p1 m2 then
-            subset l1 l2 && subset r1 l2
-          else
-            subset l1 r2 && subset r1 r2
+        if zero_bit p1 m2 then
+        subset l1 l2 && subset r1 l2
+        else
+        subset l1 r2 && subset r1 r2
         else
-          false
+        false
 
 
   let union s1 s2 = merge s1 s2
-    (* Todo replace with e Memo Module *)
+                            (* Todo replace with e Memo Module *)
 
   let rec inter s1 s2 =
     if equal s1 s2
     then s1
     else
-      match (Node.node s1,Node.node s2) with
-      | Empty, _ -> empty
-      | _, Empty -> empty
-      | Leaf k1, _ -> if mem k1 s2 then s1 else empty
-      | _, Leaf k2 -> if mem k2 s1 then s2 else empty
-      | Branch (p1,m1,l1,r1), Branch (p2,m2,l2,r2) ->
+    match (Node.node s1,Node.node s2) with
+    | Empty, _ -> empty
+    | _, Empty -> empty
+    | Leaf k1, _ -> if mem k1 s2 then s1 else empty
+    | _, 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
+        inter (if zero_bit p2 m1 then l1 else r1) s2
         else if m1 < m2 && match_prefix p1 p2 m2 then
-          inter s1 (if zero_bit p1 m2 then l2 else r2)
+        inter s1 (if zero_bit p1 m2 then l2 else r2)
         else
-          empty
+        empty
 
   let rec diff s1 s2 =
     if equal s1 s2
     then empty
     else
-      match (Node.node s1,Node.node s2) with
-      | Empty, _ -> empty
-      | _, Empty -> s1
-      | Leaf k1, _ -> if mem k1 s2 then empty else s1
-      | _, Leaf k2 -> remove k2 s1
-      | Branch (p1,m1,l1,r1), Branch (p2,m2,l2,r2) ->
+    match (Node.node s1,Node.node s2) with
+    | Empty, _ -> empty
+    | _, Empty -> s1
+    | Leaf k1, _ -> if mem k1 s2 then empty else s1
+    | _, 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
-          else
-            merge l1 (diff r1 s2)
+        if zero_bit p2 m1 then
+        merge (diff l1 s2) r1
+        else
+        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
+        if zero_bit p1 m2 then diff s1 l2 else diff s1 r2
         else
-          s1
+        s1
 
 
-(*s All the following operations ([cardinal], [iter], [fold], [for_all],
+  (*s All the following operations ([cardinal], [iter], [fold], [for_all],
     [exists], [filter], [partition], [choose], [elements]) are
     implemented as for any other kind of binary trees. *)
 
-let rec cardinal n = match Node.node n with
+  let rec cardinal n = match Node.node n with
   | Empty -> 0
   | Leaf _ -> 1
   | Branch (_,_,t0,t1) -> cardinal t0 + cardinal t1
 
-let rec iter f n = match Node.node n with
+  let rec iter f n = match Node.node n with
   | Empty -> ()
   | Leaf k -> f k
   | Branch (_,_,t0,t1) -> iter f t0; iter f t1
 
-let rec fold f s accu = match Node.node s with
+  let rec fold f s accu = match Node.node s with
   | Empty -> accu
   | Leaf k -> f k accu
   | Branch (_,_,t0,t1) -> fold f t0 (fold f t1 accu)
 
 
-let rec for_all p n = match Node.node n with
+  let rec for_all p n = match Node.node n with
   | Empty -> true
   | Leaf k -> p k
   | Branch (_,_,t0,t1) -> for_all p t0 && for_all p t1
 
-let rec exists p n = match Node.node n with
+  let rec exists p n = match Node.node n with
   | Empty -> false
   | Leaf k -> p k
   | Branch (_,_,t0,t1) -> exists p t0 || exists p t1
 
-let rec filter pr n = match Node.node n with
+  let rec filter pr n = match Node.node n with
   | Empty -> empty
   | Leaf k -> if pr k then n else empty
   | Branch (p,m,t0,t1) -> branch_ne p m (filter pr t0) (filter pr t1)
 
-let partition p s =
-  let rec part (t,f as acc) n = match Node.node n with
+  let partition p s =
+    let rec part (t,f as acc) n = match Node.node n with
     | Empty -> acc
     | Leaf k -> if p k then (add k t, f) else (t, add k f)
     | Branch (_,_,t0,t1) -> part (part acc t0) t1
-  in
-  part (empty, empty) s
+    in
+    part (empty, empty) s
 
-let rec choose n = match Node.node n with
+  let rec choose n = match Node.node n with
   | Empty -> raise Not_found
   | Leaf k -> k
   | Branch (_, _,t0,_) -> choose t0   (* we know that [t0] is non-empty *)
 
 
-let split x s =
-  let coll k (l, b, r) =
-    if k < x then add k l, b, r
-    else if k > x then l, b, add k r
-    else l, true, r
-  in
-  fold coll s (empty, false, empty)
-
-(*s Additional functions w.r.t to [Set.S]. *)
-
-let rec intersect s1 s2 = (equal s1 s2) ||
-  match (Node.node s1,Node.node s2) with
-  | Empty, _ -> false
-  | _, Empty -> false
-  | Leaf k1, _ -> mem k1 s2
-  | _, Leaf k2 -> mem k2 s1
-  | Branch (p1,m1,l1,r1), Branch (p2,m2,l2,r2) ->
-      if m1 == m2 && p1 == p2 then
+  let split x s =
+    let coll k (l, b, r) =
+      if k < x then add k l, b, r
+      else if k > x then l, b, add k r
+      else l, true, r
+    in
+    fold coll s (empty, false, empty)
+
+  (*s Additional functions w.r.t to [Set.S]. *)
+
+  let rec intersect s1 s2 = (equal s1 s2) ||
+    match (Node.node s1,Node.node s2) with
+    | Empty, _ -> false
+    | _, Empty -> false
+    | Leaf k1, _ -> mem k1 s2
+    | _, Leaf k2 -> mem k2 s1
+    | Branch (p1,m1,l1,r1), Branch (p2,m2,l2,r2) ->
+        if m1 == m2 && p1 == p2 then
         intersect l1 l2 || intersect r1 r2
-      else if m1 < m2 && match_prefix p2 p1 m1 then
+        else if m1 < m2 && match_prefix p2 p1 m1 then
         intersect (if zero_bit p2 m1 then l1 else r1) s2
-      else if m1 > m2 && match_prefix p1 p2 m2 then
+        else if m1 > m2 && match_prefix p1 p2 m2 then
         intersect s1 (if zero_bit p1 m2 then l2 else r2)
-      else
+        else
         false
 
 
-let from_list l = List.fold_left (fun acc e -> add e acc) empty l
+  let from_list l = List.fold_left (fun acc e -> add e acc) empty l
 
 
 end
@@ -367,11 +366,11 @@ module Weak = Builder(Hcons.Weak)
 
 module PosInt
   =
-  struct
-    include Make(Hcons.PosInt)
-    let print ppf s =
-      Format.pp_print_string ppf "{ ";
-      iter (fun i -> Format.fprintf ppf "%i " i) s;
-      Format.pp_print_string ppf "}";
-      Format.pp_print_flush ppf ()
-  end
+struct
+  include Make(Hcons.PosInt)
+  let print ppf s =
+    Format.pp_print_string ppf "{ ";
+    iter (fun i -> Format.fprintf ppf "%i " i) s;
+    Format.pp_print_string ppf "}";
+    Format.pp_print_flush ppf ()
+end