[sledge] Refactor Var0 into Trm.Var and Subst

Reviewed By: ngorogiannis

Differential Revision: D26250525

fbshipit-source-id: 5a61bc4ff
master
Josh Berdine 4 years ago committed by Facebook GitHub Bot
parent daaff7ad01
commit e284b06e5b

@ -7,11 +7,10 @@
(** Arithmetic terms *)
open Var_intf
include Arithmetic_intf
module Representation
(Var : VAR)
(Var : Var_intf.S)
(Trm : INDETERMINATE with type var := Var.t) =
struct
module Prod = struct

@ -7,10 +7,9 @@
(** Arithmetic terms *)
open Var_intf
include module type of Arithmetic_intf
module Representation
(Var : VAR)
(Var : Var_intf.S)
(Indeterminate : INDETERMINATE with type var := Var.t) :
REPRESENTATION with type var := Var.t with type trm := Indeterminate.t

@ -0,0 +1,78 @@
(*
* 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.
*)
(** Renaming Substitutions: injective maps from variables to variables *)
include Subst_intf
module Make (Var : VAR) = struct
module Set = Var.Set
module Map = Var.Map
type t = Var.t Map.t [@@deriving compare, equal, sexp_of]
type x = {sub: t; dom: Set.t; rng: Set.t}
let t_of_sexp = Map.t_of_sexp Var.t_of_sexp
let pp = Map.pp Var.pp Var.pp
let invariant s =
let@ () = Invariant.invariant [%here] s [%sexp_of: t] in
let domain, range =
Map.fold s (Set.empty, Set.empty)
~f:(fun ~key ~data (domain, range) ->
(* substs are injective *)
assert (not (Set.mem data range)) ;
(Set.add key domain, Set.add data range) )
in
assert (Set.disjoint domain range)
let empty = Map.empty
let is_empty = Map.is_empty
let freshen vs ~wrt =
let dom = Set.inter wrt vs in
( if Set.is_empty dom then
({sub= empty; dom= Set.empty; rng= Set.empty}, wrt)
else
let wrt = Set.union wrt vs in
let sub, rng, wrt =
Set.fold dom (empty, Set.empty, wrt) ~f:(fun x (sub, rng, wrt) ->
let x', wrt = Var.freshen x ~wrt in
let sub = Map.add_exn ~key:x ~data:x' sub in
let rng = Set.add x' rng in
(sub, rng, wrt) )
in
({sub; dom; rng}, wrt) )
|> check (fun ({sub; _}, _) -> invariant sub)
let fold sub z ~f = Map.fold ~f:(fun ~key ~data -> f key data) sub z
let domain sub = Set.of_iter (Map.keys sub)
let range sub = Set.of_iter (Map.values sub)
let invert sub =
Map.fold sub empty ~f:(fun ~key ~data sub' ->
Map.add_exn ~key:data ~data:key sub' )
|> check invariant
let restrict_dom sub0 vs =
Map.fold sub0 {sub= sub0; dom= Set.empty; rng= Set.empty}
~f:(fun ~key ~data z ->
let rng = Set.add data z.rng in
if Set.mem key vs then {z with dom= Set.add key z.dom; rng}
else (
assert (
(* all substs are injective, so the current mapping is the only
one that can cause [data] to be in [rng] *)
(not (Set.mem data (range (Map.remove key sub0))))
|| violates invariant sub0 ) ;
{z with sub= Map.remove key z.sub; rng} ) )
|> check (fun {sub; dom; rng} ->
assert (Set.equal dom (domain sub)) ;
assert (Set.equal rng (range sub0)) )
let apply sub v = Map.find v sub |> Option.value ~default:v
end

@ -5,7 +5,9 @@
* LICENSE file in the root directory of this source tree.
*)
open Var_intf
(** Renaming Substitutions: injective maps from variables to variables *)
(** Variables, parameterized over their representation *)
module Make (R : REPR) : VAR with type t = R.t
include module type of Subst_intf
module Make (Var : VAR) :
S with type var := Var.t with type set := Var.Set.t

@ -0,0 +1,46 @@
(*
* 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.
*)
(** Renaming Substitutions: injective maps from variables to variables *)
module type VAR = sig
type t [@@deriving compare, equal, sexp]
val pp : t pp
module Map : sig
include Map.S with type key := t
val t_of_sexp : (Sexp.t -> 'a) -> Sexp.t -> 'a t
end
module Set : Set.S with type elt := t
val freshen : t -> wrt:Set.t -> t * Set.t
end
module type S = sig
type var
type set
type t [@@deriving compare, equal, sexp]
type x = {sub: t; dom: set; rng: set}
val pp : t pp
val empty : t
val freshen : set -> wrt:set -> x * set
val invert : t -> t
val restrict_dom : t -> set -> x
(** restrict the domain of a substitution to a set, and yield the range of
the unrestricted substitution *)
val is_empty : t -> bool
val domain : t -> set
val range : t -> set
val fold : t -> 's -> f:(var -> var -> 's -> 's) -> 's
val apply : t -> var -> var
end

@ -54,7 +54,7 @@ and Trm : sig
module Var1 : sig
type trm := t
include Var_intf.VAR with type t = private trm
include Var_intf.S with type t = private trm
val of_ : trm -> t
val of_trm : trm -> t option
@ -153,9 +153,18 @@ end = struct
let pp = ppx (fun _ -> None)
(* Define variables as a subtype of terms *)
module Var1 = struct
module T = struct
type nonrec t = t [@@deriving compare, equal, sexp]
module V = struct
module T = struct
type nonrec t = t [@@deriving compare, equal, sexp]
type strength = t -> [`Universal | `Existential | `Anonymous] option
let pp = pp
let ppx = ppx
end
include T
let invariant x =
let@ () = Invariant.invariant [%here] x [%sexp_of: t] in
@ -166,12 +175,45 @@ end = struct
let make ~id ~name = Var {id; name} |> check invariant
let id = function Var v -> v.id | x -> violates invariant x
let name = function Var v -> v.name | x -> violates invariant x
end
include Var0.Make (T)
module Set = struct
module S = NS.Set.Make (T)
include S
include Provide_of_sexp (T)
include Provide_pp (T)
let ppx strength vs = S.pp_full (ppx strength) vs
let pp_xs fs xs =
if not (is_empty xs) then
Format.fprintf fs "@<2>∃ @[%a@] .@;<1 2>" pp xs
end
module Map = struct
include NS.Map.Make (T)
include Provide_of_sexp (T)
end
let fresh name ~wrt =
let max =
match Set.max_elt wrt with None -> 0 | Some m -> max 0 (id m)
in
let x' = make ~id:(max + 1) ~name in
(x', Set.add x' wrt)
let freshen v ~wrt = fresh (name v) ~wrt
let program ?(name = "") ~id =
assert (id > 0) ;
make ~id:(-id) ~name
let identified ~name ~id = make ~id ~name
let of_ v = v |> check invariant
let of_trm = function Var _ as v -> Some v | _ -> None
end
let of_ v = v |> check T.invariant
let of_trm = function Var _ as v -> Some v | _ -> None
include V
module Subst = Subst.Make (V)
end
let invariant e =

@ -30,7 +30,7 @@ module Arith : Arithmetic.S with type trm := t with type t = arith
module Var : sig
type trm := t
include Var_intf.VAR with type t = private trm
include Var_intf.S with type t = private trm
val of_ : trm -> t
val of_trm : trm -> t option

@ -1,129 +0,0 @@
(*
* 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.
*)
open Var_intf
(** Variables, parameterized over their representation *)
module Make (T : REPR) = struct
module T = struct
include T
type strength = t -> [`Universal | `Existential | `Anonymous] option
let ppx strength ppf v =
let id = id v in
let name = name v in
if id < 0 then Trace.pp_styled `Bold "%%%s!%i" ppf name (-id)
else
match strength v with
| None -> Format.fprintf ppf "%%%s_%i" name id
| Some `Universal -> Trace.pp_styled `Bold "%%%s_%i" ppf name id
| Some `Existential -> Trace.pp_styled `Cyan "%%%s_%i" ppf name id
| Some `Anonymous -> Trace.pp_styled `Cyan "_" ppf
let pp = ppx (fun _ -> None)
end
include T
module Map = struct
include NS.Map.Make (T)
include Provide_of_sexp (T)
end
module Set = struct
module S = NS.Set.Make (T)
include S
include Provide_of_sexp (T)
include Provide_pp (T)
let ppx strength vs = S.pp_full (ppx strength) vs
let pp_xs fs xs =
if not (is_empty xs) then
Format.fprintf fs "@<2>∃ @[%a@] .@;<1 2>" pp xs
end
let fresh name ~wrt =
let max =
match Set.max_elt wrt with None -> 0 | Some m -> max 0 (id m)
in
let x' = make ~id:(max + 1) ~name in
(x', Set.add x' wrt)
let program ?(name = "") ~id =
assert (id > 0) ;
make ~id:(-id) ~name
let identified ~name ~id = make ~id ~name
(** Variable renaming substitutions *)
module Subst = struct
type t = T.t Map.t [@@deriving compare, equal, sexp_of]
type x = {sub: t; dom: Set.t; rng: Set.t}
let t_of_sexp = Map.t_of_sexp t_of_sexp
let pp = Map.pp pp pp
let invariant s =
let@ () = Invariant.invariant [%here] s [%sexp_of: t] in
let domain, range =
Map.fold s (Set.empty, Set.empty)
~f:(fun ~key ~data (domain, range) ->
(* substs are injective *)
assert (not (Set.mem data range)) ;
(Set.add key domain, Set.add data range) )
in
assert (Set.disjoint domain range)
let empty = Map.empty
let is_empty = Map.is_empty
let freshen vs ~wrt =
let dom = Set.inter wrt vs in
( if Set.is_empty dom then
({sub= empty; dom= Set.empty; rng= Set.empty}, wrt)
else
let wrt = Set.union wrt vs in
let sub, rng, wrt =
Set.fold dom (empty, Set.empty, wrt) ~f:(fun x (sub, rng, wrt) ->
let x', wrt = fresh (name x) ~wrt in
let sub = Map.add_exn ~key:x ~data:x' sub in
let rng = Set.add x' rng in
(sub, rng, wrt) )
in
({sub; dom; rng}, wrt) )
|> check (fun ({sub; _}, _) -> invariant sub)
let fold sub z ~f = Map.fold ~f:(fun ~key ~data -> f key data) sub z
let domain sub = Set.of_iter (Map.keys sub)
let range sub = Set.of_iter (Map.values sub)
let invert sub =
Map.fold sub empty ~f:(fun ~key ~data sub' ->
Map.add_exn ~key:data ~data:key sub' )
|> check invariant
let restrict_dom sub0 vs =
Map.fold sub0 {sub= sub0; dom= Set.empty; rng= Set.empty}
~f:(fun ~key ~data z ->
let rng = Set.add data z.rng in
if Set.mem key vs then {z with dom= Set.add key z.dom; rng}
else (
assert (
(* all substs are injective, so the current mapping is the
only one that can cause [data] to be in [rng] *)
(not (Set.mem data (range (Map.remove key sub0))))
|| violates invariant sub0 ) ;
{z with sub= Map.remove key z.sub; rng} ) )
|> check (fun {sub; dom; rng} ->
assert (Set.equal dom (domain sub)) ;
assert (Set.equal rng (range sub0)) )
let apply sub v = Map.find v sub |> Option.value ~default:v
end
end

@ -5,15 +5,8 @@
* LICENSE file in the root directory of this source tree.
*)
module type REPR = sig
type t [@@deriving compare, equal, sexp]
val make : id:int -> name:string -> t
val id : t -> int
val name : t -> string
end
module type VAR = sig
(** Variables *)
module type S = sig
type t [@@deriving compare, equal, sexp]
type strength = t -> [`Universal | `Existential | `Anonymous] option
@ -29,7 +22,6 @@ module type VAR = sig
module Set : sig
include NS.Set.S with type elt := t
val sexp_of_t : t -> Sexp.t
val t_of_sexp : Sexp.t -> t
val ppx : strength -> t pp
val pp : t pp
@ -54,24 +46,5 @@ module type VAR = sig
[Var.fresh name ~wrt:(Var.Set.of_ (Var.identified ~name ~id))]. *)
(** Variable renaming substitutions *)
module Subst : sig
type var := t
type t [@@deriving compare, equal, sexp]
type x = {sub: t; dom: Set.t; rng: Set.t}
val pp : t pp
val empty : t
val freshen : Set.t -> wrt:Set.t -> x * Set.t
val invert : t -> t
val restrict_dom : t -> Set.t -> x
(** restrict the domain of a substitution to a set, and yield the range
of the unrestricted substitution *)
val is_empty : t -> bool
val domain : t -> Set.t
val range : t -> Set.t
val fold : t -> 's -> f:(var -> var -> 's -> 's) -> 's
val apply : t -> var -> var
end
module Subst : Subst.S with type var := t with type set := Set.t
end

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