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Diffstat (limited to 'pretyping/coercionops.ml')
| -rw-r--r-- | pretyping/coercionops.ml | 479 |
1 files changed, 479 insertions, 0 deletions
diff --git a/pretyping/coercionops.ml b/pretyping/coercionops.ml new file mode 100644 index 0000000000..16021b66f8 --- /dev/null +++ b/pretyping/coercionops.ml @@ -0,0 +1,479 @@ +(************************************************************************) +(* * The Coq Proof Assistant / The Coq Development Team *) +(* v * INRIA, CNRS and contributors - Copyright 1999-2019 *) +(* <O___,, * (see CREDITS file for the list of authors) *) +(* \VV/ **************************************************************) +(* // * This file is distributed under the terms of the *) +(* * GNU Lesser General Public License Version 2.1 *) +(* * (see LICENSE file for the text of the license) *) +(************************************************************************) + +open CErrors +open Util +open Pp +open Names +open Constr +open Libnames +open Globnames +open Mod_subst + +(* usage qque peu general: utilise aussi dans record *) + +(* A class is a type constructor, its type is an arity whose number of + arguments is cl_param (0 for CL_SORT and CL_FUN) *) + +type cl_typ = + | CL_SORT + | CL_FUN + | CL_SECVAR of variable + | CL_CONST of Constant.t + | CL_IND of inductive + | CL_PROJ of Projection.Repr.t + +type cl_info_typ = { + cl_param : int +} + +type coe_typ = GlobRef.t + +module CoeTypMap = GlobRef.Map_env + +type coe_info_typ = { + coe_value : GlobRef.t; + coe_local : bool; + coe_is_identity : bool; + coe_is_projection : Projection.Repr.t option; + coe_param : int; +} + +let coe_info_typ_equal c1 c2 = + GlobRef.equal c1.coe_value c2.coe_value && + c1.coe_local == c2.coe_local && + c1.coe_is_identity == c2.coe_is_identity && + c1.coe_is_projection == c2.coe_is_projection && + Int.equal c1.coe_param c2.coe_param + +let cl_typ_ord t1 t2 = match t1, t2 with + | CL_SECVAR v1, CL_SECVAR v2 -> Id.compare v1 v2 + | CL_CONST c1, CL_CONST c2 -> Constant.CanOrd.compare c1 c2 + | CL_PROJ c1, CL_PROJ c2 -> Projection.Repr.CanOrd.compare c1 c2 + | CL_IND i1, CL_IND i2 -> ind_ord i1 i2 + | _ -> pervasives_compare t1 t2 (** OK *) + +module ClTyp = struct + type t = cl_typ + let compare = cl_typ_ord +end + +module ClTypMap = Map.Make(ClTyp) + +module IntMap = Map.Make(Int) + +let cl_typ_eq t1 t2 = Int.equal (cl_typ_ord t1 t2) 0 + +type inheritance_path = coe_info_typ list + +(* table des classes, des coercions et graphe d'heritage *) + +module Bijint : +sig + module Index : + sig + type t + val compare : t -> t -> int + val equal : t -> t -> bool + val print : t -> Pp.t + end + type 'a t + val empty : 'a t + val mem : cl_typ -> 'a t -> bool + val map : Index.t -> 'a t -> cl_typ * 'a + val revmap : cl_typ -> 'a t -> Index.t * 'a + val add : cl_typ -> 'a -> 'a t -> 'a t + val dom : 'a t -> cl_typ list +end += +struct + + module Index = struct include Int let print = Pp.int end + + type 'a t = { v : (cl_typ * 'a) IntMap.t; s : int; inv : int ClTypMap.t } + let empty = { v = IntMap.empty; s = 0; inv = ClTypMap.empty } + let mem y b = ClTypMap.mem y b.inv + let map x b = IntMap.find x b.v + let revmap y b = let n = ClTypMap.find y b.inv in (n, snd (IntMap.find n b.v)) + let add x y b = + { v = IntMap.add b.s (x,y) b.v; s = b.s+1; inv = ClTypMap.add x b.s b.inv } + let dom b = List.rev (ClTypMap.fold (fun x _ acc -> x::acc) b.inv []) +end + +type cl_index = Bijint.Index.t + +let init_class_tab = + let open Bijint in + add CL_FUN { cl_param = 0 } (add CL_SORT { cl_param = 0 } empty) + +let class_tab = + Summary.ref ~name:"class_tab" (init_class_tab : cl_info_typ Bijint.t) + +let coercion_tab = + Summary.ref ~name:"coercion_tab" (CoeTypMap.empty : coe_info_typ CoeTypMap.t) + +module ClPairOrd = +struct + type t = cl_index * cl_index + let compare (i1, j1) (i2, j2) = + let c = Bijint.Index.compare i1 i2 in + if Int.equal c 0 then Bijint.Index.compare j1 j2 else c +end + +module ClPairMap = Map.Make(ClPairOrd) + +let inheritance_graph = + Summary.ref ~name:"inheritance_graph" (ClPairMap.empty : inheritance_path ClPairMap.t) + +(* ajout de nouveaux "objets" *) + +let add_new_class cl s = + if not (Bijint.mem cl !class_tab) then + class_tab := Bijint.add cl s !class_tab + +let add_new_coercion coe s = + coercion_tab := CoeTypMap.add coe s !coercion_tab + +let add_new_path x y = + inheritance_graph := ClPairMap.add x y !inheritance_graph + +(* class_info : cl_typ -> int * cl_info_typ *) + +let class_info cl = Bijint.revmap cl !class_tab + +let class_exists cl = Bijint.mem cl !class_tab + +(* class_info_from_index : int -> cl_typ * cl_info_typ *) + +let class_info_from_index i = Bijint.map i !class_tab + +let cl_fun_index = fst(class_info CL_FUN) + +let cl_sort_index = fst(class_info CL_SORT) + +(* coercion_info : coe_typ -> coe_info_typ *) + +let coercion_info coe = CoeTypMap.find coe !coercion_tab + +let coercion_exists coe = CoeTypMap.mem coe !coercion_tab + +(* find_class_type : evar_map -> constr -> cl_typ * universe_list * constr list *) + +let find_class_type sigma t = + let open EConstr in + let t', args = Reductionops.whd_betaiotazeta_stack sigma t in + match EConstr.kind sigma t' with + | Var id -> CL_SECVAR id, EInstance.empty, args + | Const (sp,u) -> CL_CONST sp, u, args + | Proj (p, c) when not (Projection.unfolded p) -> + CL_PROJ (Projection.repr p), EInstance.empty, (c :: args) + | Ind (ind_sp,u) -> CL_IND ind_sp, u, args + | Prod _ -> CL_FUN, EInstance.empty, [] + | Sort _ -> CL_SORT, EInstance.empty, [] + | _ -> raise Not_found + + +let subst_cl_typ subst ct = match ct with + CL_SORT + | CL_FUN + | CL_SECVAR _ -> ct + | CL_PROJ c -> + let c' = subst_proj_repr subst c in + if c' == c then ct else CL_PROJ c' + | CL_CONST c -> + let c',t = subst_con subst c in + if c' == c then ct else (match t with + | None -> CL_CONST c' + | Some t -> + pi1 (find_class_type Evd.empty (EConstr.of_constr t.Univ.univ_abstracted_value))) + | CL_IND i -> + let i' = subst_ind subst i in + if i' == i then ct else CL_IND i' + +(*CSC: here we should change the datatype for coercions: it should be possible + to declare any term as a coercion *) +let subst_coe_typ subst t = subst_global_reference subst t + +(* class_of : Term.constr -> int *) + +let class_of env sigma t = + let (t, n1, i, u, args) = + try + let (cl, u, args) = find_class_type sigma t in + let (i, { cl_param = n1 } ) = class_info cl in + (t, n1, i, u, args) + with Not_found -> + let t = Tacred.hnf_constr env sigma t in + let (cl, u, args) = find_class_type sigma t in + let (i, { cl_param = n1 } ) = class_info cl in + (t, n1, i, u, args) + in + if Int.equal (List.length args) n1 then t, i else raise Not_found + +let inductive_class_of ind = fst (class_info (CL_IND ind)) + +let class_args_of env sigma c = pi3 (find_class_type sigma c) + +let string_of_class = function + | CL_FUN -> "Funclass" + | CL_SORT -> "Sortclass" + | CL_CONST sp -> + string_of_qualid (Nametab.shortest_qualid_of_global Id.Set.empty (GlobRef.ConstRef sp)) + | CL_PROJ sp -> + let sp = Projection.Repr.constant sp in + string_of_qualid (Nametab.shortest_qualid_of_global Id.Set.empty (GlobRef.ConstRef sp)) + | CL_IND sp -> + string_of_qualid (Nametab.shortest_qualid_of_global Id.Set.empty (GlobRef.IndRef sp)) + | CL_SECVAR sp -> + string_of_qualid (Nametab.shortest_qualid_of_global Id.Set.empty (GlobRef.VarRef sp)) + +let pr_class x = str (string_of_class x) + +(* lookup paths *) + +let lookup_path_between_class (s,t) = + ClPairMap.find (s,t) !inheritance_graph + +let lookup_path_to_fun_from_class s = + lookup_path_between_class (s,cl_fun_index) + +let lookup_path_to_sort_from_class s = + lookup_path_between_class (s,cl_sort_index) + +(* advanced path lookup *) + +let apply_on_class_of env sigma t cont = + try + let (cl,u,args) = find_class_type sigma t in + let (i, { cl_param = n1 } ) = class_info cl in + if not (Int.equal (List.length args) n1) then raise Not_found; + t, cont i + with Not_found -> + (* Is it worth to be more incremental on the delta steps? *) + let t = Tacred.hnf_constr env sigma t in + let (cl, u, args) = find_class_type sigma t in + let (i, { cl_param = n1 } ) = class_info cl in + if not (Int.equal (List.length args) n1) then raise Not_found; + t, cont i + +let lookup_path_between env sigma (s,t) = + let (s,(t,p)) = + apply_on_class_of env sigma s (fun i -> + apply_on_class_of env sigma t (fun j -> + lookup_path_between_class (i,j))) in + (s,t,p) + +let lookup_path_to_fun_from env sigma s = + apply_on_class_of env sigma s lookup_path_to_fun_from_class + +let lookup_path_to_sort_from env sigma s = + apply_on_class_of env sigma s lookup_path_to_sort_from_class + +let mkNamed = let open GlobRef in function + | ConstRef c -> EConstr.mkConst c + | VarRef v -> EConstr.mkVar v + | ConstructRef c -> EConstr.mkConstruct c + | IndRef i -> EConstr.mkInd i + +let get_coercion_constructor env coe = + let evd = Evd.from_env env in + let red x = fst (Reductionops.whd_all_stack env evd x) in + match EConstr.kind evd (red (mkNamed coe.coe_value)) with + | Constr.Construct (c, _) -> + c, Inductiveops.constructor_nrealargs env c -1 + | _ -> raise Not_found + +let lookup_pattern_path_between env (s,t) = + let i = inductive_class_of s in + let j = inductive_class_of t in + List.map (get_coercion_constructor env) (ClPairMap.find (i,j) !inheritance_graph) + +(* rajouter une coercion dans le graphe *) + +let path_printer : ((cl_index * cl_index) * inheritance_path -> Pp.t) ref = + ref (fun _ -> str "<a class path>") + +let install_path_printer f = path_printer := f + +let print_path x = !path_printer x + +let path_comparator : (Environ.env -> Evd.evar_map -> cl_index -> inheritance_path -> inheritance_path -> bool) ref = + ref (fun _ _ _ _ _ -> false) + +let install_path_comparator f = path_comparator := f + +let compare_path p q = !path_comparator p q + +let warn_ambiguous_path = + CWarnings.create ~name:"ambiguous-paths" ~category:"typechecker" + (fun l -> prlist_with_sep fnl (fun (c,p,q) -> + str"New coercion path " ++ print_path (c,p) ++ + if List.is_empty q then + str" is not definitionally an identity function." + else + str" is ambiguous with existing " ++ print_path (c, q) ++ str".") l) + +(* add_coercion_in_graph : coe_index * cl_index * cl_index -> unit + coercion,source,target *) + +let different_class_params env i = + let ci = class_info_from_index i in + if (snd ci).cl_param > 0 then true + else + match fst ci with + | CL_IND i -> Environ.is_polymorphic env (GlobRef.IndRef i) + | CL_CONST c -> Environ.is_polymorphic env (GlobRef.ConstRef c) + | _ -> false + +let add_coercion_in_graph env sigma (ic,source,target) = + let old_inheritance_graph = !inheritance_graph in + let ambig_paths = + (ref [] : ((cl_index * cl_index) * inheritance_path * inheritance_path) list ref) in + let try_add_new_path (i,j as ij) p = + (* If p is a cycle, we check whether p is definitionally an identity + function or not. If it is not, we report p as an ambiguous inheritance + path. *) + if Bijint.Index.equal i j && not (compare_path env sigma i p []) then + ambig_paths := (ij,p,[])::!ambig_paths; + if not (Bijint.Index.equal i j) || different_class_params env i then + match lookup_path_between_class ij with + | q -> + (* p has the same source and target classes as an existing path q. We + report them as ambiguous inheritance paths if + 1. p and q have no common element, and + 2. p and q are not convertible. + If 1 does not hold, say p = p1 @ [c] @ p2 and q = q1 @ [c] @ q2, + convertibility of p1 and q1, also, p2 and q2 should be checked; thus, + checking the ambiguity of p and q is redundant with them. *) + if not (List.exists (fun c -> List.exists (coe_info_typ_equal c) q) p || + compare_path env sigma i p q) then + ambig_paths := (ij,p,q)::!ambig_paths; + false + | exception Not_found -> (add_new_path ij p; true) + else + false + in + let try_add_new_path1 ij p = + let _ = try_add_new_path ij p in () + in + if try_add_new_path (source,target) [ic] then begin + ClPairMap.iter + (fun (s,t) p -> + if not (Bijint.Index.equal s t) then begin + if Bijint.Index.equal t source then begin + try_add_new_path1 (s,target) (p@[ic]); + ClPairMap.iter + (fun (u,v) q -> + if not (Bijint.Index.equal u v) && Bijint.Index.equal u target then + try_add_new_path1 (s,v) (p@[ic]@q)) + old_inheritance_graph + end; + if Bijint.Index.equal s target then try_add_new_path1 (source,t) (ic::p) + end) + old_inheritance_graph + end; + match !ambig_paths with [] -> () | _ -> warn_ambiguous_path !ambig_paths + +type coercion = { + coercion_type : coe_typ; + coercion_local : bool; + coercion_is_id : bool; + coercion_is_proj : Projection.Repr.t option; + coercion_source : cl_typ; + coercion_target : cl_typ; + coercion_params : int; +} + +let subst_coercion subst c = + let coe = subst_coe_typ subst c.coercion_type in + let cls = subst_cl_typ subst c.coercion_source in + let clt = subst_cl_typ subst c.coercion_target in + let clp = Option.Smart.map (subst_proj_repr subst) c.coercion_is_proj in + if c.coercion_type == coe && c.coercion_source == cls && + c.coercion_target == clt && c.coercion_is_proj == clp + then c + else { c with coercion_type = coe; coercion_source = cls; + coercion_target = clt; coercion_is_proj = clp; } + +(* Computation of the class arity *) + +let reference_arity_length env sigma ref = + let t, _ = Typeops.type_of_global_in_context env ref in + List.length (fst (Reductionops.splay_arity env sigma (EConstr.of_constr t))) + +let projection_arity_length env sigma p = + let len = reference_arity_length env sigma (GlobRef.ConstRef (Projection.Repr.constant p)) in + len - Projection.Repr.npars p + +let class_params env sigma = function + | CL_FUN | CL_SORT -> 0 + | CL_CONST sp -> reference_arity_length env sigma (GlobRef.ConstRef sp) + | CL_PROJ sp -> projection_arity_length env sigma sp + | CL_SECVAR sp -> reference_arity_length env sigma (GlobRef.VarRef sp) + | CL_IND sp -> reference_arity_length env sigma (GlobRef.IndRef sp) + +(* add_class : cl_typ -> locality_flag option -> bool -> unit *) + +let add_class env sigma cl = + add_new_class cl { cl_param = class_params env sigma cl } + +let declare_coercion env sigma c = + let () = add_class env sigma c.coercion_source in + let () = add_class env sigma c.coercion_target in + let is, _ = class_info c.coercion_source in + let it, _ = class_info c.coercion_target in + let xf = + { coe_value = c.coercion_type; + coe_local = c.coercion_local; + coe_is_identity = c.coercion_is_id; + coe_is_projection = c.coercion_is_proj; + coe_param = c.coercion_params; + } in + let () = add_new_coercion c.coercion_type xf in + add_coercion_in_graph env sigma (xf,is,it) + +(* For printing purpose *) +let pr_cl_index = Bijint.Index.print + +let classes () = Bijint.dom !class_tab +let coercions () = + List.rev (CoeTypMap.fold (fun _ y acc -> y::acc) !coercion_tab []) + +let inheritance_graph () = + ClPairMap.bindings !inheritance_graph + +let coercion_of_reference r = + let ref = Nametab.global r in + if not (coercion_exists ref) then + user_err ~hdr:"try_add_coercion" + (Nametab.pr_global_env Id.Set.empty ref ++ str" is not a coercion."); + ref + +module CoercionPrinting = + struct + type t = coe_typ + module Set = GlobRef.Set + let encode _env = coercion_of_reference + let subst = subst_coe_typ + let printer x = Nametab.pr_global_env Id.Set.empty x + let key = ["Printing";"Coercion"] + let title = "Explicitly printed coercions: " + let member_message x b = + str "Explicit printing of coercion " ++ printer x ++ + str (if b then " is set" else " is unset") + end + +module PrintingCoercion = Goptions.MakeRefTable(CoercionPrinting) + +let hide_coercion coe = + if not (PrintingCoercion.active coe) then + let coe_info = coercion_info coe in + Some coe_info.coe_param + else None |
