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Diffstat (limited to 'pretyping/evarutil.ml')
| -rw-r--r-- | pretyping/evarutil.ml | 872 |
1 files changed, 0 insertions, 872 deletions
diff --git a/pretyping/evarutil.ml b/pretyping/evarutil.ml deleted file mode 100644 index e23e5a53..00000000 --- a/pretyping/evarutil.ml +++ /dev/null @@ -1,872 +0,0 @@ -(************************************************************************) -(* v * The Coq Proof Assistant / The Coq Development Team *) -(* <O___,, * INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2016 *) -(* \VV/ **************************************************************) -(* // * This file is distributed under the terms of the *) -(* * GNU Lesser General Public License Version 2.1 *) -(************************************************************************) - -open Errors -open Util -open Pp -open Names -open Term -open Vars -open Context -open Termops -open Namegen -open Pre_env -open Environ -open Evd -open Reductionops -open Pretype_errors - -(** Combinators *) - -let evd_comb0 f evdref = - let (evd',x) = f !evdref in - evdref := evd'; - x - -let evd_comb1 f evdref x = - let (evd',y) = f !evdref x in - evdref := evd'; - y - -let evd_comb2 f evdref x y = - let (evd',z) = f !evdref x y in - evdref := evd'; - z - -let e_new_global evdref x = - evd_comb1 (Evd.fresh_global (Global.env())) evdref x - -let new_global evd x = - Evd.fresh_global (Global.env()) evd x - -(****************************************************) -(* Expanding/testing/exposing existential variables *) -(****************************************************) - -(* flush_and_check_evars fails if an existential is undefined *) - -exception Uninstantiated_evar of existential_key - -let rec flush_and_check_evars sigma c = - match kind_of_term c with - | Evar (evk,_ as ev) -> - (match existential_opt_value sigma ev with - | None -> raise (Uninstantiated_evar evk) - | Some c -> flush_and_check_evars sigma c) - | _ -> map_constr (flush_and_check_evars sigma) c - -(* let nf_evar_key = Profile.declare_profile "nf_evar" *) -(* let nf_evar = Profile.profile2 nf_evar_key Reductionops.nf_evar *) -let nf_evar = Reductionops.nf_evar -let j_nf_evar sigma j = - { uj_val = nf_evar sigma j.uj_val; - uj_type = nf_evar sigma j.uj_type } -let j_nf_betaiotaevar sigma j = - { uj_val = nf_evar sigma j.uj_val; - uj_type = Reductionops.nf_betaiota sigma j.uj_type } -let jl_nf_evar sigma jl = List.map (j_nf_evar sigma) jl -let jv_nf_betaiotaevar sigma jl = - Array.map (j_nf_betaiotaevar sigma) jl -let jv_nf_evar sigma = Array.map (j_nf_evar sigma) -let tj_nf_evar sigma {utj_val=v;utj_type=t} = - {utj_val=nf_evar sigma v;utj_type=t} - -let env_nf_evar sigma env = - process_rel_context - (fun d e -> push_rel (map_rel_declaration (nf_evar sigma) d) e) env - -let env_nf_betaiotaevar sigma env = - process_rel_context - (fun d e -> - push_rel (map_rel_declaration (Reductionops.nf_betaiota sigma) d) e) env - -let nf_evars_universes evm = - Universes.nf_evars_and_universes_opt_subst (Reductionops.safe_evar_value evm) - (Evd.universe_subst evm) - -let nf_evars_and_universes evm = - let evm = Evd.nf_constraints evm in - evm, nf_evars_universes evm - -let e_nf_evars_and_universes evdref = - evdref := Evd.nf_constraints !evdref; - nf_evars_universes !evdref, Evd.universe_subst !evdref - -let nf_evar_map_universes evm = - let evm = Evd.nf_constraints evm in - let subst = Evd.universe_subst evm in - if Univ.LMap.is_empty subst then evm, nf_evar evm - else - let f = nf_evars_universes evm in - Evd.raw_map (fun _ -> map_evar_info f) evm, f - -let nf_named_context_evar sigma ctx = - Context.map_named_context (nf_evar sigma) ctx - -let nf_rel_context_evar sigma ctx = - Context.map_rel_context (nf_evar sigma) ctx - -let nf_env_evar sigma env = - let nc' = nf_named_context_evar sigma (Environ.named_context env) in - let rel' = nf_rel_context_evar sigma (Environ.rel_context env) in - push_rel_context rel' (reset_with_named_context (val_of_named_context nc') env) - -let nf_evar_info evc info = map_evar_info (nf_evar evc) info - -let nf_evar_map evm = - Evd.raw_map (fun _ evi -> nf_evar_info evm evi) evm - -let nf_evar_map_undefined evm = - Evd.raw_map_undefined (fun _ evi -> nf_evar_info evm evi) evm - -(*-------------------*) -(* Auxiliary functions for the conversion algorithms modulo evars - *) - -(* A probably faster though more approximative variant of - [has_undefined (nf_evar c)]: instances are not substituted and - maybe an evar occurs in an instance and it would disappear by - instantiation *) - -let has_undefined_evars evd t = - let rec has_ev t = - match kind_of_term t with - | Evar (ev,args) -> - (match evar_body (Evd.find evd ev) with - | Evar_defined c -> - has_ev c; Array.iter has_ev args - | Evar_empty -> - raise NotInstantiatedEvar) - | _ -> iter_constr has_ev t in - try let _ = has_ev t in false - with (Not_found | NotInstantiatedEvar) -> true - -let is_ground_term evd t = - not (has_undefined_evars evd t) - -let is_ground_env evd env = - let is_ground_decl = function - (_,Some b,_) -> is_ground_term evd b - | _ -> true in - List.for_all is_ground_decl (rel_context env) && - List.for_all is_ground_decl (named_context env) - -(* Memoization is safe since evar_map and environ are applicative - structures *) -let memo f = - let m = ref None in - fun x y -> match !m with - | Some (x', y', r) when x == x' && y == y' -> r - | _ -> let r = f x y in m := Some (x, y, r); r - -let is_ground_env = memo is_ground_env - -(* Return the head evar if any *) - -exception NoHeadEvar - -let head_evar = - let rec hrec c = match kind_of_term c with - | Evar (evk,_) -> evk - | Case (_,_,c,_) -> hrec c - | App (c,_) -> hrec c - | Cast (c,_,_) -> hrec c - | _ -> raise NoHeadEvar - in - hrec - -(* Expand head evar if any (currently consider only applications but I - guess it should consider Case too) *) - -let whd_head_evar_stack sigma c = - let rec whrec (c, l as s) = - match kind_of_term c with - | Evar (evk,args as ev) -> - let v = - try Some (existential_value sigma ev) - with NotInstantiatedEvar | Not_found -> None in - begin match v with - | None -> s - | Some c -> whrec (c, l) - end - | Cast (c,_,_) -> whrec (c, l) - | App (f,args) -> whrec (f, args :: l) - | _ -> s - in - whrec (c, []) - -let whd_head_evar sigma c = - let (f, args) = whd_head_evar_stack sigma c in - (** optim: don't reallocate if empty/singleton *) - match args with - | [] -> f - | [arg] -> mkApp (f, arg) - | _ -> mkApp (f, Array.concat args) - -(**********************) -(* Creating new metas *) -(**********************) - -let meta_counter_summary_name = "meta counter" - -(* Generator of metavariables *) -let new_meta = - let meta_ctr = Summary.ref 0 ~name:meta_counter_summary_name in - fun () -> incr meta_ctr; !meta_ctr - -let mk_new_meta () = mkMeta(new_meta()) - -(* The list of non-instantiated existential declarations (order is important) *) - -let non_instantiated sigma = - let listev = Evd.undefined_map sigma in - Evar.Map.smartmap (fun evi -> nf_evar_info sigma evi) listev - -(************************) -(* Manipulating filters *) -(************************) - -let make_pure_subst evi args = - snd (List.fold_right - (fun (id,b,c) (args,l) -> - match args with - | a::rest -> (rest, (id,a)::l) - | _ -> anomaly (Pp.str "Instance does not match its signature")) - (evar_filtered_context evi) (Array.rev_to_list args,[])) - -(**********************) -(* Creating new evars *) -(**********************) - -let evar_counter_summary_name = "evar counter" - -(* Generator of existential names *) -let new_untyped_evar = - let evar_ctr = Summary.ref 0 ~name:evar_counter_summary_name in - fun () -> incr evar_ctr; Evar.unsafe_of_int !evar_ctr - -(*------------------------------------* - * functional operations on evar sets * - *------------------------------------*) - -(* [push_rel_context_to_named_context] builds the defining context and the - * initial instance of an evar. If the evar is to be used in context - * - * Gamma = a1 ... an xp ... x1 - * \- named part -/ \- de Bruijn part -/ - * - * then the x1...xp are turned into variables so that the evar is declared in - * context - * - * a1 ... an xp ... x1 - * \----------- named part ------------/ - * - * but used applied to the initial instance "a1 ... an Rel(p) ... Rel(1)" - * so that ev[a1:=a1 ... an:=an xp:=Rel(p) ... x1:=Rel(1)] is correctly typed - * in context Gamma. - * - * Remark 1: The instance is reverted in practice (i.e. Rel(1) comes first) - * Remark 2: If some of the ai or xj are definitions, we keep them in the - * instance. This is necessary so that no unfolding of local definitions - * happens when inferring implicit arguments (consider e.g. the problem - * "x:nat; x':=x; f:forall y, y=y -> Prop |- f _ (refl_equal x')" which - * produces the equation "?y[x,x']=?y[x,x']" =? "x'=x'": we want - * the hole to be instantiated by x', not by x (which would have been - * the case in [invert_definition] if x' had disappeared from the instance). - * Note that at any time, if, in some context env, the instance of - * declaration x:A is t and the instance of definition x':=phi(x) is u, then - * we have the property that u and phi(t) are convertible in env. - *) - -let subst2 subst vsubst c = - substl subst (replace_vars vsubst c) - -let push_rel_context_to_named_context env typ = - (* compute the instances relative to the named context and rel_context *) - let ids = List.map pi1 (named_context env) in - let inst_vars = List.map mkVar ids in - let inst_rels = List.rev (rel_list 0 (nb_rel env)) in - let replace_var_named_declaration id0 id (id',b,t) = - let id' = if Id.equal id0 id' then id else id' in - let vsubst = [id0 , mkVar id] in - let b = match b with - | None -> None - | Some c -> Some (replace_vars vsubst c) - in - id', b, replace_vars vsubst t - in - let replace_var_named_context id0 id env = - let nc = Environ.named_context env in - let nc' = List.map (replace_var_named_declaration id0 id) nc in - Environ.reset_with_named_context (val_of_named_context nc') env - in - let extract_if_neq id = function - | Anonymous -> None - | Name id' when id_ord id id' = 0 -> None - | Name id' -> Some id' - in - (* move the rel context to a named context and extend the named instance *) - (* with vars of the rel context *) - (* We do keep the instances corresponding to local definition (see above) *) - let (subst, vsubst, _, env) = - Context.fold_rel_context - (fun (na,c,t) (subst, vsubst, avoid, env) -> - let id = - (* ppedrot: we want to infer nicer names for the refine tactic, but - keeping at the same time backward compatibility in other code - using this function. For now, we only attempt to preserve the - old behaviour of Program, but ultimately, one should do something - about this whole name generation problem. *) - if Flags.is_program_mode () then next_name_away na avoid - else next_ident_away (id_of_name_using_hdchar env t na) avoid - in - match extract_if_neq id na with - | Some id0 when not (is_section_variable id0) -> - (* spiwack: if [id<>id0], rather than introducing a new - binding named [id], we will keep [id0] (the name given - by the user) and rename [id0] into [id] in the named - context. Unless [id] is a section variable. *) - let subst = List.map (replace_vars [id0,mkVar id]) subst in - let vsubst = (id0,mkVar id)::vsubst in - let d = (id0, Option.map (subst2 subst vsubst) c, subst2 subst vsubst t) in - let env = replace_var_named_context id0 id env in - (mkVar id0 :: subst, vsubst, id::avoid, push_named d env) - | _ -> - (* spiwack: if [id0] is a section variable renaming it is - incorrect. We revert to a less robust behaviour where - the new binder has name [id]. Which amounts to the same - behaviour than when [id=id0]. *) - let d = (id,Option.map (subst2 subst vsubst) c,subst2 subst vsubst t) in - (mkVar id :: subst, vsubst, id::avoid, push_named d env) - ) - (rel_context env) ~init:([], [], ids, env) in - (named_context_val env, subst2 subst vsubst typ, inst_rels@inst_vars, subst, vsubst) - -(*------------------------------------* - * Entry points to define new evars * - *------------------------------------*) - -let default_source = (Loc.ghost,Evar_kinds.InternalHole) - -let restrict_evar evd evk filter candidates = - let evk' = new_untyped_evar () in - let evd = Evd.restrict evk evk' filter ?candidates evd in - Evd.declare_future_goal evk' evd, evk' - -let new_pure_evar_full evd evi = - let evk = new_untyped_evar () in - let evd = Evd.add evd evk evi in - let evd = Evd.declare_future_goal evk evd in - (evd, evk) - -let new_pure_evar sign evd ?(src=default_source) ?filter ?candidates ?store ?naming ?(principal=false) typ = - let default_naming = - if principal then - (* waiting for a more principled approach - (unnamed evars, private names?) *) - Misctypes.IntroFresh (Names.Id.of_string "tmp_goal") - else - Misctypes.IntroAnonymous - in - let naming = Option.default default_naming naming in - let newevk = new_untyped_evar() in - let evd = evar_declare sign newevk typ ~src ?filter ?candidates ?store ~naming evd in - let evd = - if principal then Evd.declare_principal_goal newevk evd - else Evd.declare_future_goal newevk evd - in - (evd,newevk) - -let new_evar_instance sign evd typ ?src ?filter ?candidates ?store ?naming ?principal instance = - assert (not !Flags.debug || - List.distinct (ids_of_named_context (named_context_of_val sign))); - let evd,newevk = new_pure_evar sign evd ?src ?filter ?candidates ?store ?naming ?principal typ in - (evd,mkEvar (newevk,Array.of_list instance)) - -(* [new_evar] declares a new existential in an env env with type typ *) -(* Converting the env into the sign of the evar to define *) -let new_evar env evd ?src ?filter ?candidates ?store ?naming ?principal typ = - let sign,typ',instance,subst,vsubst = push_rel_context_to_named_context env typ in - let candidates = Option.map (List.map (subst2 subst vsubst)) candidates in - let instance = - match filter with - | None -> instance - | Some filter -> Filter.filter_list filter instance in - new_evar_instance sign evd typ' ?src ?filter ?candidates ?store ?naming ?principal instance - -let new_type_evar env evd ?src ?filter ?naming ?principal rigid = - let evd', s = new_sort_variable rigid evd in - let evd', e = new_evar env evd' ?src ?filter ?naming ?principal (mkSort s) in - evd', (e, s) - -let e_new_type_evar env evdref ?src ?filter ?naming ?principal rigid = - let evd', c = new_type_evar env !evdref ?src ?filter ?naming ?principal rigid in - evdref := evd'; - c - -let new_Type ?(rigid=Evd.univ_flexible) env evd = - let evd', s = new_sort_variable rigid evd in - evd', mkSort s - -let e_new_Type ?(rigid=Evd.univ_flexible) env evdref = - let evd', s = new_sort_variable rigid !evdref in - evdref := evd'; mkSort s - - (* The same using side-effect *) -let e_new_evar env evdref ?(src=default_source) ?filter ?candidates ?store ?naming ?principal ty = - let (evd',ev) = new_evar env !evdref ~src:src ?filter ?candidates ?store ?naming ?principal ty in - evdref := evd'; - ev - -(* This assumes an evar with identity instance and generalizes it over only - the De Bruijn part of the context *) -let generalize_evar_over_rels sigma (ev,args) = - let evi = Evd.find sigma ev in - let sign = named_context_of_val evi.evar_hyps in - List.fold_left2 - (fun (c,inst as x) a d -> - if isRel a then (mkNamedProd_or_LetIn d c,a::inst) else x) - (evi.evar_concl,[]) (Array.to_list args) sign - -(************************************) -(* Removing a dependency in an evar *) -(************************************) - -type clear_dependency_error = -| OccurHypInSimpleClause of Id.t option -| EvarTypingBreak of existential - -exception ClearDependencyError of Id.t * clear_dependency_error - -let cleared = Store.field () - -exception Depends of Id.t - -let rec check_and_clear_in_constr env evdref err ids c = - (* returns a new constr where all the evars have been 'cleaned' - (ie the hypotheses ids have been removed from the contexts of - evars) *) - let check id' = - if Id.Set.mem id' ids then - raise (ClearDependencyError (id',err)) - in - match kind_of_term c with - | Var id' -> - check id'; c - - | ( Const _ | Ind _ | Construct _ ) -> - let vars = Environ.vars_of_global env c in - Id.Set.iter check vars; c - - | Evar (evk,l as ev) -> - if Evd.is_defined !evdref evk then - (* If evk is already defined we replace it by its definition *) - let nc = whd_evar !evdref c in - (check_and_clear_in_constr env evdref err ids nc) - else - (* We check for dependencies to elements of ids in the - evar_info corresponding to e and in the instance of - arguments. Concurrently, we build a new evar - corresponding to e where hypotheses of ids have been - removed *) - let evi = Evd.find_undefined !evdref evk in - let ctxt = Evd.evar_filtered_context evi in - let (rids,filter) = - List.fold_right2 - (fun (rid, ob,c as h) a (ri,filter) -> - try - (* Check if some id to clear occurs in the instance - a of rid in ev and remember the dependency *) - let check id = if Id.Set.mem id ids then raise (Depends id) in - let () = Id.Set.iter check (collect_vars a) in - (* Check if some rid to clear in the context of ev - has dependencies in another hyp of the context of ev - and transitively remember the dependency *) - let check id _ = - if occur_var_in_decl (Global.env ()) id h - then raise (Depends id) - in - let () = Id.Map.iter check ri in - (* No dependency at all, we can keep this ev's context hyp *) - (ri, true::filter) - with Depends id -> (Id.Map.add rid id ri, false::filter)) - ctxt (Array.to_list l) (Id.Map.empty,[]) in - (* Check if some rid to clear in the context of ev has dependencies - in the type of ev and adjust the source of the dependency *) - let _nconcl = - try - let nids = Id.Map.domain rids in - check_and_clear_in_constr env evdref (EvarTypingBreak ev) nids (evar_concl evi) - with ClearDependencyError (rid,err) -> - raise (ClearDependencyError (Id.Map.find rid rids,err)) in - - if Id.Map.is_empty rids then c - else - let origfilter = Evd.evar_filter evi in - let filter = Evd.Filter.apply_subfilter origfilter filter in - let evd,_ = restrict_evar !evdref evk filter None in - evdref := evd; - (* spiwack: hacking session to mark the old [evk] as having been "cleared" *) - let evi = Evd.find !evdref evk in - let extra = evi.evar_extra in - let extra' = Store.set extra cleared true in - let evi' = { evi with evar_extra = extra' } in - evdref := Evd.add !evdref evk evi' ; - (* spiwack: /hacking session *) - whd_evar !evdref c - - | _ -> map_constr (check_and_clear_in_constr env evdref err ids) c - -let clear_hyps_in_evi_main env evdref hyps terms ids = - (* clear_hyps_in_evi erases hypotheses ids in hyps, checking if some - hypothesis does not depend on a element of ids, and erases ids in - the contexts of the evars occurring in evi *) - let terms = - List.map (check_and_clear_in_constr env evdref (OccurHypInSimpleClause None) ids) terms in - let nhyps = - let check_context ((id,ob,c) as decl) = - let err = OccurHypInSimpleClause (Some id) in - let ob' = Option.smartmap (fun c -> check_and_clear_in_constr env evdref err ids c) ob in - let c' = check_and_clear_in_constr env evdref err ids c in - if ob == ob' && c == c' then decl else (id, ob', c') - in - let check_value vk = match force_lazy_val vk with - | None -> vk - | Some (_, d) -> - if (Id.Set.for_all (fun e -> not (Id.Set.mem e d)) ids) then - (* v does depend on any of ids, it's ok *) - vk - else - (* v depends on one of the cleared hyps: - we forget the computed value *) - dummy_lazy_val () - in - remove_hyps ids check_context check_value hyps - in - (nhyps,terms) - -let clear_hyps_in_evi env evdref hyps concl ids = - match clear_hyps_in_evi_main env evdref hyps [concl] ids with - | (nhyps,[nconcl]) -> (nhyps,nconcl) - | _ -> assert false - -let clear_hyps2_in_evi env evdref hyps t concl ids = - match clear_hyps_in_evi_main env evdref hyps [t;concl] ids with - | (nhyps,[t;nconcl]) -> (nhyps,t,nconcl) - | _ -> assert false - -(* spiwack: a few functions to gather evars on which goals depend. *) -let queue_set q is_dependent set = - Evar.Set.iter (fun a -> Queue.push (is_dependent,a) q) set -let queue_term q is_dependent c = - queue_set q is_dependent (evars_of_term c) - -let process_dependent_evar q acc evm is_dependent e = - let evi = Evd.find evm e in - (* Queues evars appearing in the types of the goal (conclusion, then - hypotheses), they are all dependent. *) - queue_term q true evi.evar_concl; - List.iter begin fun (_,b,t) -> - queue_term q true t; - match b with - | None -> () - | Some b -> queue_term q true b - end (Environ.named_context_of_val evi.evar_hyps); - match evi.evar_body with - | Evar_empty -> - if is_dependent then Evar.Map.add e None acc else acc - | Evar_defined b -> - let subevars = evars_of_term b in - (* evars appearing in the definition of an evar [e] are marked - as dependent when [e] is dependent itself: if [e] is a - non-dependent goal, then, unless they are reach from another - path, these evars are just other non-dependent goals. *) - queue_set q is_dependent subevars; - if is_dependent then Evar.Map.add e (Some subevars) acc else acc - -let gather_dependent_evars q evm = - let acc = ref Evar.Map.empty in - while not (Queue.is_empty q) do - let (is_dependent,e) = Queue.pop q in - (* checks if [e] has already been added to [!acc] *) - begin if not (Evar.Map.mem e !acc) then - acc := process_dependent_evar q !acc evm is_dependent e - end - done; - !acc - -let gather_dependent_evars evm l = - let q = Queue.create () in - List.iter (fun a -> Queue.add (false,a) q) l; - gather_dependent_evars q evm - -(* /spiwack *) - -(** The following functions return the set of undefined evars - contained in the object, the defined evars being traversed. - This is roughly a combination of the previous functions and - [nf_evar]. *) - -let undefined_evars_of_term evd t = - let rec evrec acc c = - match kind_of_term c with - | Evar (n, l) -> - let acc = Array.fold_left evrec acc l in - (try match (Evd.find evd n).evar_body with - | Evar_empty -> Evar.Set.add n acc - | Evar_defined c -> evrec acc c - with Not_found -> anomaly ~label:"undefined_evars_of_term" (Pp.str "evar not found")) - | _ -> fold_constr evrec acc c - in - evrec Evar.Set.empty t - -let undefined_evars_of_named_context evd nc = - List.fold_right (fun (_, b, t) s -> - Option.fold_left (fun s t -> - Evar.Set.union s (undefined_evars_of_term evd t)) - (Evar.Set.union s (undefined_evars_of_term evd t)) b) - nc Evar.Set.empty - -let undefined_evars_of_evar_info evd evi = - Evar.Set.union (undefined_evars_of_term evd evi.evar_concl) - (Evar.Set.union - (match evi.evar_body with - | Evar_empty -> Evar.Set.empty - | Evar_defined b -> undefined_evars_of_term evd b) - (undefined_evars_of_named_context evd - (named_context_of_val evi.evar_hyps))) - -(* [check_evars] fails if some unresolved evar remains *) - -let check_evars env initial_sigma sigma c = - let rec proc_rec c = - match kind_of_term c with - | Evar (evk,_ as ev) -> - (match existential_opt_value sigma ev with - | Some c -> proc_rec c - | None -> - if not (Evd.mem initial_sigma evk) then - let (loc,k) = evar_source evk sigma in - match k with - | Evar_kinds.ImplicitArg (gr, (i, id), false) -> () - | _ -> error_unsolvable_implicit loc env sigma evk None) - | _ -> iter_constr proc_rec c - in proc_rec c - -(* spiwack: this is a more complete version of - {!Termops.occur_evar}. The latter does not look recursively into an - [evar_map]. If unification only need to check superficially, tactics - do not have this luxury, and need the more complete version. *) -let occur_evar_upto sigma n c = - let rec occur_rec c = match kind_of_term c with - | Evar (sp,_) when Evar.equal sp n -> raise Occur - | Evar e -> Option.iter occur_rec (existential_opt_value sigma e) - | _ -> iter_constr occur_rec c - in - try occur_rec c; false with Occur -> true - - -(****************************************) -(* Operations on value/type constraints *) -(****************************************) - -type type_constraint = types option - -type val_constraint = constr option - -(* Old comment... - * Basically, we have the following kind of constraints (in increasing - * strength order): - * (false,(None,None)) -> no constraint at all - * (true,(None,None)) -> we must build a judgement which _TYPE is a kind - * (_,(None,Some ty)) -> we must build a judgement which _TYPE is ty - * (_,(Some v,_)) -> we must build a judgement which _VAL is v - * Maybe a concrete datatype would be easier to understand. - * We differentiate (true,(None,None)) from (_,(None,Some Type)) - * because otherwise Case(s) would be misled, as in - * (n:nat) Case n of bool [_]nat end would infer the predicate Type instead - * of Set. - *) - -(* The empty type constraint *) -let empty_tycon = None - -(* Builds a type constraint *) -let mk_tycon ty = Some ty - -(* Constrains the value of a type *) -let empty_valcon = None - -(* Builds a value constraint *) -let mk_valcon c = Some c - -let idx = Namegen.default_dependent_ident - -(* Refining an evar to a product *) - -let define_pure_evar_as_product evd evk = - let evi = Evd.find_undefined evd evk in - let evenv = evar_env evi in - let id = next_ident_away idx (ids_of_named_context (evar_context evi)) in - let concl = whd_betadeltaiota evenv evd evi.evar_concl in - let s = destSort concl in - let evd1,(dom,u1) = - new_type_evar evenv evd univ_flexible_alg ~filter:(evar_filter evi) in - let evd2,rng = - let newenv = push_named (id, None, dom) evenv in - let src = evar_source evk evd1 in - let filter = Filter.extend 1 (evar_filter evi) in - if is_prop_sort s then - (* Impredicative product, conclusion must fall in [Prop]. *) - new_evar newenv evd1 concl ~src ~filter - else - let status = univ_flexible_alg in - let evd3, (rng, srng) = - new_type_evar newenv evd1 status ~src ~filter in - let prods = Univ.sup (univ_of_sort u1) (univ_of_sort srng) in - let evd3 = Evd.set_leq_sort evenv evd3 (Type prods) s in - evd3, rng - in - let prod = mkProd (Name id, dom, subst_var id rng) in - let evd3 = Evd.define evk prod evd2 in - evd3,prod - -(* Refine an applied evar to a product and returns its instantiation *) - -let define_evar_as_product evd (evk,args) = - let evd,prod = define_pure_evar_as_product evd evk in - (* Quick way to compute the instantiation of evk with args *) - let na,dom,rng = destProd prod in - let evdom = mkEvar (fst (destEvar dom), args) in - let evrngargs = Array.cons (mkRel 1) (Array.map (lift 1) args) in - let evrng = mkEvar (fst (destEvar rng), evrngargs) in - evd,mkProd (na, evdom, evrng) - -(* Refine an evar with an abstraction - - I.e., solve x1..xq |- ?e:T(x1..xq) with e:=λy:A.?e'[x1..xq,y] where: - - either T(x1..xq) = πy:A(x1..xq).B(x1..xq,y) - or T(x1..xq) = ?d[x1..xq] and we define ?d := πy:?A.?B - with x1..xq |- ?A:Type and x1..xq,y |- ?B:Type - - x1..xq,y:A |- ?e':B -*) - -let define_pure_evar_as_lambda env evd evk = - let evi = Evd.find_undefined evd evk in - let evenv = evar_env evi in - let typ = whd_betadeltaiota evenv evd (evar_concl evi) in - let evd1,(na,dom,rng) = match kind_of_term typ with - | Prod (na,dom,rng) -> (evd,(na,dom,rng)) - | Evar ev' -> let evd,typ = define_evar_as_product evd ev' in evd,destProd typ - | _ -> error_not_product_loc Loc.ghost env evd typ in - let avoid = ids_of_named_context (evar_context evi) in - let id = - next_name_away_with_default_using_types "x" na avoid (whd_evar evd dom) in - let newenv = push_named (id, None, dom) evenv in - let filter = Filter.extend 1 (evar_filter evi) in - let src = evar_source evk evd1 in - let evd2,body = new_evar newenv evd1 ~src (subst1 (mkVar id) rng) ~filter in - let lam = mkLambda (Name id, dom, subst_var id body) in - Evd.define evk lam evd2, lam - -let define_evar_as_lambda env evd (evk,args) = - let evd,lam = define_pure_evar_as_lambda env evd evk in - (* Quick way to compute the instantiation of evk with args *) - let na,dom,body = destLambda lam in - let evbodyargs = Array.cons (mkRel 1) (Array.map (lift 1) args) in - let evbody = mkEvar (fst (destEvar body), evbodyargs) in - evd,mkLambda (na, dom, evbody) - -let rec evar_absorb_arguments env evd (evk,args as ev) = function - | [] -> evd,ev - | a::l -> - (* TODO: optimize and avoid introducing intermediate evars *) - let evd,lam = define_pure_evar_as_lambda env evd evk in - let _,_,body = destLambda lam in - let evk = fst (destEvar body) in - evar_absorb_arguments env evd (evk, Array.cons a args) l - -(* Refining an evar to a sort *) - -let define_evar_as_sort env evd (ev,args) = - let evd, u = new_univ_variable univ_rigid evd in - let evi = Evd.find_undefined evd ev in - let s = Type u in - let concl = whd_betadeltaiota (evar_env evi) evd evi.evar_concl in - let sort = destSort concl in - let evd' = Evd.define ev (mkSort s) evd in - Evd.set_leq_sort env evd' (Type (Univ.super u)) sort, s - -(* We don't try to guess in which sort the type should be defined, since - any type has type Type. May cause some trouble, but not so far... *) - -let judge_of_new_Type evd = - let evd', s = new_univ_variable univ_rigid evd in - evd', { uj_val = mkSort (Type s); uj_type = mkSort (Type (Univ.super s)) } - -(* Propagation of constraints through application and abstraction: - Given a type constraint on a functional term, returns the type - constraint on its domain and codomain. If the input constraint is - an evar instantiate it with the product of 2 new evars. *) - -let split_tycon loc env evd tycon = - let rec real_split evd c = - let t = whd_betadeltaiota env evd c in - match kind_of_term t with - | Prod (na,dom,rng) -> evd, (na, dom, rng) - | Evar ev (* ev is undefined because of whd_betadeltaiota *) -> - let (evd',prod) = define_evar_as_product evd ev in - let (_,dom,rng) = destProd prod in - evd',(Anonymous, dom, rng) - | App (c,args) when isEvar c -> - let (evd',lam) = define_evar_as_lambda env evd (destEvar c) in - real_split evd' (mkApp (lam,args)) - | _ -> error_not_product_loc loc env evd c - in - match tycon with - | None -> evd,(Anonymous,None,None) - | Some c -> - let evd', (n, dom, rng) = real_split evd c in - evd', (n, mk_tycon dom, mk_tycon rng) - -let valcon_of_tycon x = x -let lift_tycon n = Option.map (lift n) - -let pr_tycon env = function - None -> str "None" - | Some t -> Termops.print_constr_env env t - -let subterm_source evk (loc,k) = - let evk = match k with - | Evar_kinds.SubEvar (evk) -> evk - | _ -> evk in - (loc,Evar_kinds.SubEvar evk) - - -(** Term exploration up to instantiation. *) -let kind_of_term_upto sigma t = - Constr.kind (Reductionops.whd_evar sigma t) - -(** [eq_constr_univs_test sigma1 sigma2 t u] tests equality of [t] and - [u] up to existential variable instantiation and equalisable - universes. The term [t] is interpreted in [sigma1] while [u] is - interpreted in [sigma2]. The universe constraints in [sigma2] are - assumed to be an extention of those in [sigma1]. *) -let eq_constr_univs_test sigma1 sigma2 t u = - (* spiwack: mild code duplication with {!Evd.eq_constr_univs}. *) - let open Evd in - let b, c = - Universes.eq_constr_univs_infer_with - (fun t -> kind_of_term_upto sigma1 t) - (fun u -> kind_of_term_upto sigma2 u) - (universes sigma2) t u - in - if b then - try let _ = add_universe_constraints sigma2 c in true - with Univ.UniverseInconsistency _ | UniversesDiffer -> false - else false |