You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

88 lines
2.3 KiB

(*
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*)
(** Qset - Set with (signed) rational multiplicity for each element *)
open Import0
include Qset_intf
module Make (Elt : OrderedType) = struct
module M = Stdlib.Map.Make (Elt)
type elt = Elt.t
type t = Q.t M.t
let compare = M.compare Q.compare
let equal = M.equal Q.equal
let hash_fold_t hash_fold_elt s m =
let hash_fold_q s q = Hash.fold_int s (Hashtbl.hash q) in
M.fold
(fun key data state -> hash_fold_q (hash_fold_elt state key) data)
m
(Hash.fold_int s (M.cardinal m))
let sexp_of_t s =
let sexp_of_q q = Sexp.Atom (Q.to_string q) in
List.sexp_of_t
(Sexplib.Conv.sexp_of_pair Elt.sexp_of_t sexp_of_q)
(M.bindings s)
let t_of_sexp elt_of_sexp sexp =
let q_of_sexp = function
| Sexp.Atom s -> Q.of_string s
| _ -> assert false
in
List.fold_left
~f:(fun m (k, v) -> M.add k v m)
~init:M.empty
(List.t_of_sexp
(Sexplib.Conv.pair_of_sexp elt_of_sexp q_of_sexp)
sexp)
let pp sep pp_elt fs s = List.pp sep pp_elt fs (M.bindings s)
let empty = M.empty
let if_nz q = if Q.equal Q.zero q then None else Some q
let add m x i =
M.update x (function Some j -> if_nz Q.(i + j) | None -> if_nz i) m
let remove m x = M.remove x m
let union m n =
M.merge
(fun _ m_q n_q ->
match (m_q, n_q) with
| Some i, Some j -> if_nz Q.(i + j)
| Some i, None | None, Some i -> Some i
| None, None -> None )
m n
let map m ~f =
let m' = M.empty in
let m, m' =
M.fold
(fun x i (m, m') ->
let x', i' = f x i in
if x' == x then
if Q.equal i' i then (m, m') else (M.add x i' m, m')
else (M.remove x m, add m' x' i') )
m (m, m')
in
M.fold (fun x i m -> add m x i) m' m
let map_counts m ~f = M.mapi f m
let length m = M.cardinal m
let count m x = try M.find x m with Not_found -> Q.zero
let min_elt_exn = M.min_binding
let min_elt = M.min_binding_opt
let to_list m = M.bindings m
let iter m ~f = M.iter f m
let exists m ~f = M.exists f m
let fold m ~f ~init = M.fold f m init
end