1 (******************************************************************************)
2 (* SXSI : XPath evaluator *)
3 (* Kim Nguyen (Kim.Nguyen@nicta.com.au) *)
4 (* Copyright NICTA 2008 *)
5 (* Distributed under the terms of the LGPL (see LICENCE) *)
6 (******************************************************************************)
15 val is_empty : t -> bool
16 val is_any : t -> bool
17 val is_finite : t -> bool
18 val kind : t -> [ `Finite | `Cofinite ]
19 val singleton : elt -> t
20 val mem : elt -> t -> bool
21 val add : elt -> t -> t
22 val remove : elt -> t -> t
25 val diff : t -> t -> t
27 val compare : t -> t -> int
28 val subset : t -> t -> bool
29 val kind_split : t list -> t * t
30 val fold : (elt -> 'a -> 'a) -> t -> 'a -> 'a
31 val for_all : (elt -> bool) -> t -> bool
32 val exists : (elt -> bool) -> t -> bool
33 val filter : (elt -> bool) -> t -> t
34 val partition : (elt -> bool) -> t -> t * t
35 val cardinal : t -> int
36 val elements : t -> elt list
37 val from_list : elt list -> t
40 val equal : t -> t -> bool
43 module Make (E : Sigs.Set) : S with type elt = E.elt =
47 type t = Finite of E.t | CoFinite of E.t
50 let empty = Finite E.empty
51 let any = CoFinite E.empty
53 let is_empty = function
54 Finite s when E.is_empty s -> true
58 CoFinite s when E.is_empty s -> true
61 let is_finite = function
62 | Finite _ -> true | _ -> false
68 let mem x = function Finite s -> E.mem x s
69 | CoFinite s -> not (E.mem x s)
71 let singleton x = Finite (E.singleton x)
73 | Finite s -> Finite (E.add e s)
74 | CoFinite s -> CoFinite (E.remove e s)
75 let remove e = function
76 | Finite s -> Finite (E.remove e s)
77 | CoFinite s -> CoFinite (E.add e s)
79 let cup s t = match (s,t) with
80 | Finite s, Finite t -> Finite (E.union s t)
81 | CoFinite s, CoFinite t -> CoFinite ( E.inter s t)
82 | Finite s, CoFinite t -> CoFinite (E.diff t s)
83 | CoFinite s, Finite t-> CoFinite (E.diff s t)
85 let cap s t = match (s,t) with
86 | Finite s, Finite t -> Finite (E.inter s t)
87 | CoFinite s, CoFinite t -> CoFinite (E.union s t)
88 | Finite s, CoFinite t -> Finite (E.diff s t)
89 | CoFinite s, Finite t-> Finite (E.diff t s)
91 let diff s t = match (s,t) with
92 | Finite s, Finite t -> Finite (E.diff s t)
93 | Finite s, CoFinite t -> Finite(E.inter s t)
94 | CoFinite s, Finite t -> CoFinite(E.union t s)
95 | CoFinite s, CoFinite t -> Finite (E.diff t s)
98 | Finite s -> CoFinite s
99 | CoFinite s -> Finite s
101 let compare s t = match (s,t) with
102 | Finite s , Finite t -> E.compare s t
103 | CoFinite s , CoFinite t -> E.compare t s
104 | Finite _, CoFinite _ -> -1
105 | CoFinite _, Finite _ -> 1
107 let subset s t = match (s,t) with
108 | Finite s , Finite t -> E.subset s t
109 | CoFinite s , CoFinite t -> E.subset t s
110 | Finite s, CoFinite t -> E.is_empty (E.inter s t)
111 | CoFinite _, Finite _ -> false
113 (* given a list l of type t list,
114 returns two sets (f,c) where :
115 - f is the union of all the finite sets of l
116 - c is the union of all the cofinite sets of l
117 - f and c are disjoint
118 Invariant : cup f c = List.fold_left cup empty l
120 We treat the CoFinite part explicitely :
125 let rec next_finite_cofinite facc cacc = function
126 | [] -> Finite facc, CoFinite (E.diff cacc facc)
127 | Finite s ::r -> next_finite_cofinite (E.union s facc) cacc r
128 | CoFinite _ ::r when E.is_empty cacc -> next_finite_cofinite facc cacc r
129 | CoFinite s ::r -> next_finite_cofinite facc (E.inter cacc s) r
131 let rec first_cofinite facc = function
133 | Finite s :: r-> first_cofinite (E.union s facc) r
134 | CoFinite s :: r -> next_finite_cofinite facc s r
136 first_cofinite E.empty l
138 let fold f t a = match t with
139 | Finite s -> E.fold f s a
140 | CoFinite _ -> raise InfiniteSet
142 let for_all f = function
143 | Finite s -> E.for_all f s
144 | CoFinite _ -> raise InfiniteSet
146 let exists f = function
147 | Finite s -> E.exists f s
148 | CoFinite _ -> raise InfiniteSet
150 let filter f = function
151 | Finite s -> Finite (E.filter f s)
152 | CoFinite _ -> raise InfiniteSet
154 let partition f = function
155 | Finite s -> let a,b = E.partition f s in Finite a,Finite b
156 | CoFinite _ -> raise InfiniteSet
158 let cardinal = function
159 | Finite s -> E.cardinal s
160 | CoFinite _ -> raise InfiniteSet
162 let elements = function
163 | Finite s -> E.elements s
164 | CoFinite _ -> raise InfiniteSet
167 Finite(List.fold_left (fun x a -> E.add a x ) E.empty l)
169 let choose = function
170 Finite s -> E.choose s
171 | _ -> raise InfiniteSet
175 | Finite x, Finite y | CoFinite x, CoFinite y -> E.equal x y
179 function Finite x -> (E.hash x)
180 | CoFinite x -> ( ~-(E.hash x) land max_int)