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 (******************************************************************************)
16 val is_empty : t -> bool
17 val is_any : t -> bool
18 val is_finite : t -> bool
19 val kind : t -> [ `Finite | `Cofinite ]
20 val singleton : elt -> t
21 val mem : elt -> t -> bool
22 val add : elt -> t -> t
23 val remove : elt -> t -> t
26 val diff : t -> t -> t
28 val compare : t -> t -> int
29 val subset : t -> t -> bool
30 val kind_split : t list -> t * t
31 val fold : (elt -> 'a -> 'a) -> t -> 'a -> 'a
32 val for_all : (elt -> bool) -> t -> bool
33 val exists : (elt -> bool) -> t -> bool
34 val filter : (elt -> bool) -> t -> t
35 val partition : (elt -> bool) -> t -> t * t
36 val cardinal : t -> int
37 val elements : t -> elt list
38 val from_list : elt list -> t
41 val equal : t -> t -> bool
42 val positive : t -> set
43 val negative : t -> set
46 module Make (E : Sigs.Set) : S with type elt = E.elt and type set = E.t =
50 type t = Finite of E.t | CoFinite of E.t
53 let empty = Finite E.empty
54 let any = CoFinite E.empty
56 let is_empty = function
57 Finite s when E.is_empty s -> true
61 CoFinite s when E.is_empty s -> true
64 let is_finite = function
65 | Finite _ -> true | _ -> false
71 let mem x = function Finite s -> E.mem x s
72 | CoFinite s -> not (E.mem x s)
74 let singleton x = Finite (E.singleton x)
76 | Finite s -> Finite (E.add e s)
77 | CoFinite s -> CoFinite (E.remove e s)
78 let remove e = function
79 | Finite s -> Finite (E.remove e s)
80 | CoFinite s -> CoFinite (E.add e s)
82 let cup s t = match (s,t) with
83 | Finite s, Finite t -> Finite (E.union s t)
84 | CoFinite s, CoFinite t -> CoFinite ( E.inter s t)
85 | Finite s, CoFinite t -> CoFinite (E.diff t s)
86 | CoFinite s, Finite t-> CoFinite (E.diff s t)
88 let cap s t = match (s,t) with
89 | Finite s, Finite t -> Finite (E.inter s t)
90 | CoFinite s, CoFinite t -> CoFinite (E.union s t)
91 | Finite s, CoFinite t -> Finite (E.diff s t)
92 | CoFinite s, Finite t-> Finite (E.diff t s)
94 let diff s t = match (s,t) with
95 | Finite s, Finite t -> Finite (E.diff s t)
96 | Finite s, CoFinite t -> Finite(E.inter s t)
97 | CoFinite s, Finite t -> CoFinite(E.union t s)
98 | CoFinite s, CoFinite t -> Finite (E.diff t s)
101 | Finite s -> CoFinite s
102 | CoFinite s -> Finite s
104 let compare s t = match (s,t) with
105 | Finite s , Finite t -> E.compare s t
106 | CoFinite s , CoFinite t -> E.compare t s
107 | Finite _, CoFinite _ -> -1
108 | CoFinite _, Finite _ -> 1
110 let subset s t = match (s,t) with
111 | Finite s , Finite t -> E.subset s t
112 | CoFinite s , CoFinite t -> E.subset t s
113 | Finite s, CoFinite t -> E.is_empty (E.inter s t)
114 | CoFinite _, Finite _ -> false
116 (* given a list l of type t list,
117 returns two sets (f,c) where :
118 - f is the union of all the finite sets of l
119 - c is the union of all the cofinite sets of l
120 - f and c are disjoint
121 Invariant : cup f c = List.fold_left cup empty l
123 We treat the CoFinite part explicitely :
128 let rec next_finite_cofinite facc cacc = function
129 | [] -> Finite facc, CoFinite (E.diff cacc facc)
130 | Finite s ::r -> next_finite_cofinite (E.union s facc) cacc r
131 | CoFinite _ ::r when E.is_empty cacc -> next_finite_cofinite facc cacc r
132 | CoFinite s ::r -> next_finite_cofinite facc (E.inter cacc s) r
134 let rec first_cofinite facc = function
136 | Finite s :: r-> first_cofinite (E.union s facc) r
137 | CoFinite s :: r -> next_finite_cofinite facc s r
139 first_cofinite E.empty l
141 let fold f t a = match t with
142 | Finite s -> E.fold f s a
143 | CoFinite _ -> raise InfiniteSet
145 let for_all f = function
146 | Finite s -> E.for_all f s
147 | CoFinite _ -> raise InfiniteSet
149 let exists f = function
150 | Finite s -> E.exists f s
151 | CoFinite _ -> raise InfiniteSet
153 let filter f = function
154 | Finite s -> Finite (E.filter f s)
155 | CoFinite _ -> raise InfiniteSet
157 let partition f = function
158 | Finite s -> let a,b = E.partition f s in Finite a,Finite b
159 | CoFinite _ -> raise InfiniteSet
161 let cardinal = function
162 | Finite s -> E.cardinal s
163 | CoFinite _ -> raise InfiniteSet
165 let elements = function
166 | Finite s -> E.elements s
167 | CoFinite _ -> raise InfiniteSet
170 Finite(List.fold_left (fun x a -> E.add a x ) E.empty l)
172 let choose = function
173 Finite s -> E.choose s
174 | _ -> raise InfiniteSet
178 | Finite x, Finite y | CoFinite x, CoFinite y -> E.equal x y
182 function Finite x -> (E.hash x)
183 | CoFinite x -> ( ~-(E.hash x) land max_int)