(* *)
(***********************************************************************)
-(*
- Time-stamp: <Last modified on 2013-01-30 19:07:53 CET by Kim Nguyen>
-*)
-
(* Modified by Kim Nguyen *)
(* The Patricia trees are themselves deeply hash-consed. The module
provides a Make (and Weak) functor to build hash-consed patricia
INCLUDE "utils.ml"
-include Sigs.PTSET
+include Ptset_sig
module type HConsBuilder =
- functor (H : Sigs.AUX.HashedType) -> Hcons.S with type data = H.t
+ functor (H : Common_sig.HashedType) -> Hcons.S with type data = H.t
module Builder (HCB : HConsBuilder) (H : Hcons.Abstract) :
S with type elt = H.t =
| 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 : Common_sig.HashedType
+ with type t = Node.t set
+ =
struct
type t = Node.t set
let equal x y =
| Branch(b1,i1,l1,r1), Branch(b2,i2,l2,r2) ->
b1 == b2 && i1 == i2 && (Node.equal l1 l2) && (Node.equal r1 r2)
- | _ -> false
+ | (Empty|Leaf _|Branch _), _ -> false
let hash = function
| Empty -> 0
let empty = Node.make Empty
- let is_empty s = (Node.node s) == Empty
+ let is_empty s = s.Node.node == Empty
let branch p m l r = Node.make (Branch(p,m,l,r))
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 ************)
-
- let zero_bit k m = (k land m) == 0
+ (******** from here on, only use the smart constructors ************)
let singleton k = leaf k
let is_singleton n =
- match Node.node n with Leaf _ -> true
- | _ -> false
+ match n.Node.node with
+ | Leaf _ -> true
+ | Branch _ | Empty -> false
let mem (k:elt) n =
- let kid = Uid.to_int (H.uid k) in
- let rec loop n = match Node.node n with
+ let kid = (H.uid k :> int) in
+ let rec loop n = match n.Node.node with
| Empty -> false
| Leaf j -> k == j
- | Branch (p, _, l, r) -> if kid <= p then loop l else loop r
+ | Branch (p, _, l, r) -> loop (if kid <= p then l else r)
in loop n
- let rec min_elt n = match Node.node n with
+ let rec min_elt n = match n.Node.node with
| Empty -> raise Not_found
| Leaf k -> k
| Branch (_,_,s,_) -> min_elt s
- let rec max_elt n = match Node.node n with
+ let rec max_elt n = match n.Node.node with
| 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
+ let rec elements_aux acc n = match n.Node.node with
| Empty -> acc
| Leaf k -> k :: acc
| Branch (_,_,l,r) -> elements_aux (elements_aux acc r) l
in
elements_aux [] s
+
+ let zero_bit k m = (k land m) == 0
+
let mask k m = (k lor (m-1)) land (lnot m)
- let naive_highest_bit x =
- assert (x < 256);
- 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
-
- let hbit = Array.init 256 naive_highest_bit
- (*
- 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)
- with
- _ -> raise (Invalid_argument ("highest_bit " ^ (string_of_int x)))
-
- let highest_bit64 x =
- let n = x lsr 32 in if n != 0 then highest_bit n lsl 32
- else highest_bit x
-
- let branching_bit p0 p1 = highest_bit64 (p0 lxor p1)
+ external int_of_bool : bool -> int = "%identity"
+
+ let hb32 v0 =
+ let v = v0 lor (v0 lsr 1) in
+ let v = v lor (v lsr 2) in
+ let v = v lor (v lsr 4) in
+ let v = v lor (v lsr 8) in
+ let v = v lor (v lsr 16) in
+ ((v + 1) lsr 1) + (int_of_bool (v0 == 0))
+
+ let hb64 v0 =
+ let v = v0 lor (v0 lsr 1) in
+ let v = v lor (v lsr 2) in
+ let v = v lor (v lsr 4) in
+ let v = v lor (v lsr 8) in
+ let v = v lor (v lsr 16) in
+ let v = v lor (v lsr 32) in
+ ((v + 1) lsr 1) + (int_of_bool (v0 == 0))
+
+
+ let branching_bit p0 p1 = hb64 (p0 lxor p1)
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
+ branch_ne msk m t0 t1
else
- branch_ne msk m t1 t0
+ 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);
- let rec ins n = match Node.node n with
+ let rec ins n = match n.Node.node with
| Empty -> leaf k
- | Leaf j -> if j == k then n else join kid (leaf k) (Uid.to_int (H.uid j)) n
+ | 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
+ branch_ne p m t0 (ins t1)
else
- join kid (leaf k) p n
+ 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
+ let kid = (H.uid k :> int) in
+ let rec rmv n = match n.Node.node with
| 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
+ if zero_bit kid m then
+ branch_ne p m (rmv t0) t1
+ else
+ branch_ne p m t0 (rmv t1)
else
- branch_ne p m t0 (rmv t1)
- else
- n
+ n
in
rmv t
- (* should run in O(1) thanks to hash consing *)
+ (* runs in O(1) thanks to hash consing *)
- let equal a b = Node.equal a b
+ let equal a b = a == b
let compare a b = (Uid.to_int (Node.uid a)) - (Uid.to_int (Node.uid b))
if equal s t (* This is cheap thanks to hash-consing *)
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) ->
- if m == n && match_prefix q p m then
- 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)
- 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)
- else
- (* The prefixes disagree. *)
- join p s q t
+ match s.Node.node, t.Node.node 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) ->
+ if m == n && match_prefix q p m then
+ 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)
+ 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)
+ else
+ (* The prefixes disagree. *)
+ join p s q t
let rec subset s1 s2 = (equal s1 s2) ||
- match (Node.node s1,Node.node s2) with
+ match s1.Node.node, s2.Node.node with
| 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
+ if zero_bit p1 m2 then
+ subset l1 l2 && subset r1 l2
+ else
+ subset l1 r2 && subset r1 r2
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) ->
- if m1 == m2 && p1 == p2 then
- 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
- inter s1 (if zero_bit p1 m2 then l2 else r2)
- else
- empty
+ match s1.Node.node, s2.Node.node 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)
+ 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
+ inter s1 (if zero_bit p1 m2 then l2 else r2)
+ else
+ 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) ->
- if m1 == m2 && p1 == p2 then
- 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)
- else if m1 < m2 && match_prefix p1 p2 m2 then
- if zero_bit p1 m2 then diff s1 l2 else diff s1 r2
- else
- s1
+ match s1.Node.node, s2.Node.node 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)
+ 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)
+ else if m1 < m2 && match_prefix p1 p2 m2 then
+ if zero_bit p1 m2 then diff s1 l2 else diff s1 r2
+ else
+ s1
(*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 n.Node.node 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 n.Node.node 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_left f s accu = match s.Node.node with
+ | Empty -> accu
+ | Leaf k -> f k accu
+ | Branch (_,_,t0,t1) -> fold_left f t1 (fold_left f t0 accu)
+
+ let rec fold_right f s accu = match s.Node.node with
| Empty -> accu
| Leaf k -> f k accu
- | Branch (_,_,t0,t1) -> fold f t0 (fold f t1 accu)
+ | Branch (_,_,t0,t1) -> fold_right f t0 (fold_right f t1 accu)
+ let fold f s accu = fold_left f s accu
- let rec for_all p n = match Node.node n with
+ let rec for_all p n = match n.Node.node 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 n.Node.node 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 n.Node.node 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)
+ | Branch (p,m,t0,t1) -> let n0 = filter pr t0 in
+ let n1 = filter pr t1 in
+ branch_ne p m n0 n1
let partition p s =
- let rec part (t,f as acc) n = match Node.node n with
+ let rec part (t,f as acc) n = match n.Node.node 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
- let rec choose n = match Node.node n with
+ let rec choose n = match n.Node.node with
| Empty -> raise Not_found
| Leaf k -> k
| Branch (_, _,t0,_) -> choose t0 (* we know that [t0] is non-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
+ match s1.Node.node, s2.Node.node 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
- intersect (if zero_bit p2 m1 then l1 else r1) s2
- else if m1 > m2 && match_prefix p1 p2 m2 then
- intersect s1 (if zero_bit p1 m2 then l2 else r2)
+ intersect l1 l2 || intersect r1 r2
+ 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
+ intersect s1 (if zero_bit p1 m2 then l2 else r2)
else
- false
+ false
let from_list l = List.fold_left (fun acc e -> add e acc) empty l