|
(************************************************************************)
(* * The Coq Proof Assistant / The Coq Development Team *)
(* v * INRIA, CNRS and contributors - Copyright 1999-2018 *)
(* <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 Names
open Context
open Constr
open Environ
open Evd
open Termops
open Namegen
module RelDecl = Context.Rel.Declaration
module NamedDecl = Context.Named.Declaration
let safe_evar_value sigma ev =
let ev = EConstr.of_existential ev in
try Some (EConstr.Unsafe.to_constr @@ Evd.existential_value sigma ev)
with NotInstantiatedEvar | Not_found -> None
(** 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 new_global evd x =
let (evd, c) = Evd.fresh_global (Global.env()) evd x in
(evd, c)
(****************************************************)
(* Expanding/testing/exposing existential variables *)
(****************************************************)
let finalize ?abort_on_undefined_evars sigma f =
let sigma = minimize_universes sigma in
let uvars = ref Univ.LSet.empty in
let v = f (fun c ->
let varsc = EConstr.universes_of_constr sigma c in
let c = EConstr.to_constr ?abort_on_undefined_evars sigma c in
uvars := Univ.LSet.union !uvars varsc;
c)
in
let sigma = restrict_universe_context sigma !uvars in
sigma, v
(* flush_and_check_evars fails if an existential is undefined *)
exception Uninstantiated_evar of Evar.t
let rec flush_and_check_evars sigma c =
match kind c with
| Evar (evk,_ as ev) ->
(match existential_opt_value0 sigma ev with
| None -> raise (Uninstantiated_evar evk)
| Some c -> flush_and_check_evars sigma c)
| _ -> Constr.map (flush_and_check_evars sigma) c
let flush_and_check_evars sigma c =
flush_and_check_evars sigma (EConstr.Unsafe.to_constr c)
(** Term exploration up to instantiation. *)
let kind_of_term_upto = EConstr.kind_upto
let nf_evar0 sigma t = EConstr.to_constr ~abort_on_undefined_evars:false sigma (EConstr.of_constr t)
let whd_evar = EConstr.whd_evar
let nf_evar sigma c = EConstr.of_constr (EConstr.to_constr ~abort_on_undefined_evars:false sigma c)
let j_nf_evar sigma j =
{ uj_val = nf_evar sigma j.uj_val;
uj_type = nf_evar sigma j.uj_type }
let jl_nf_evar sigma jl = List.map (j_nf_evar 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 nf_evars_universes evm =
UnivSubst.nf_evars_and_universes_opt_subst (safe_evar_value evm)
(Evd.universe_subst evm)
let nf_named_context_evar sigma ctx =
Context.Named.map (nf_evar0 sigma) ctx
let nf_rel_context_evar sigma ctx =
Context.Rel.map (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 (EConstr.rel_context env) in
EConstr.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
*)
let has_undefined_evars evd t =
let rec has_ev t =
match EConstr.kind evd t with
| Evar _ -> raise NotInstantiatedEvar
| _ -> EConstr.iter evd 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_rel_decl = function
| RelDecl.LocalDef (_,b,_) -> is_ground_term evd (EConstr.of_constr b)
| _ -> true in
let is_ground_named_decl = function
| NamedDecl.LocalDef (_,b,_) -> is_ground_term evd (EConstr.of_constr b)
| _ -> true in
List.for_all is_ground_rel_decl (rel_context env) &&
List.for_all is_ground_named_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 sigma c =
(* FIXME: this breaks if using evar-insensitive code *)
let c = EConstr.Unsafe.to_constr c in
let rec hrec c = match kind c with
| Evar (evk,_) -> evk
| Case (_,_,c,_) -> hrec c
| App (c,_) -> hrec c
| Cast (c,_,_) -> hrec c
| Proj (p, c) -> hrec c
| _ -> raise NoHeadEvar
in
hrec c
(* 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) =
match EConstr.kind sigma c with
| Cast (c,_,_) -> whrec (c, l)
| App (f,args) -> whrec (f, args :: l)
| c -> (EConstr.of_kind c, l)
in
whrec (c, [])
let whd_head_evar sigma c =
let open EConstr in
let (f, args) = whd_head_evar_stack sigma c in
match args with
| [arg] -> mkApp (f, arg)
| _ -> mkApp (f, Array.concat args)
(**********************)
(* Creating new metas *)
(**********************)
let meta_counter_summary_name = "meta counter"
(* Generator of metavariables *)
let meta_ctr, meta_counter_summary_tag =
Summary.ref_tag 0 ~name:meta_counter_summary_name
let new_meta () = incr meta_ctr; !meta_ctr
let mk_new_meta () = EConstr.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.Smart.map (fun evi -> nf_evar_info sigma evi) listev
(************************)
(* Manipulating filters *)
(************************)
let make_pure_subst evi args =
snd (List.fold_right
(fun decl (args,l) ->
match args with
| a::rest -> (rest, (NamedDecl.get_id decl, a)::l)
| _ -> anomaly (Pp.str "Instance does not match its signature."))
(evar_filtered_context evi) (Array.rev_to_list args,[]))
(*------------------------------------*
* 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 next_ident_away id avoid =
let avoid id = Id.Set.mem id avoid in
next_ident_away_from id avoid
let next_name_away na avoid =
let avoid id = Id.Set.mem id avoid in
let id = match na with Name id -> id | Anonymous -> default_non_dependent_ident in
next_ident_away_from id avoid
type subst_val =
| SRel of int
| SVar of Id.t
type csubst = {
csubst_len : int;
(** Cardinal of [csubst_rel] *)
csubst_var : Constr.t Id.Map.t;
(** A mapping of variables to variables. We use the more general
[Constr.t] to share allocations, but all values are of shape [Var _]. *)
csubst_rel : Constr.t Int.Map.t;
(** A contiguous mapping of integers to variables. Same remark for values. *)
csubst_rev : subst_val Id.Map.t;
(** Reverse mapping of the substitution *)
}
(** This type represents a name substitution for the named and De Bruijn parts of
an environment. For efficiency we also store the reverse substitution.
Invariant: all identifiers in the codomain of [csubst_var] and [csubst_rel]
must be pairwise distinct. *)
let empty_csubst = {
csubst_len = 0;
csubst_rel = Int.Map.empty;
csubst_var = Id.Map.empty;
csubst_rev = Id.Map.empty;
}
let csubst_subst { csubst_len = k; csubst_var = v; csubst_rel = s } c =
(* Safe because this is a substitution *)
let c = EConstr.Unsafe.to_constr c in
let rec subst n c = match Constr.kind c with
| Rel m ->
if m <= n then c
else if m - n <= k then Int.Map.find (k - m + n) s
else mkRel (m - k)
| Var id ->
begin try Id.Map.find id v with Not_found -> c end
| _ -> Constr.map_with_binders succ subst n c
in
let c = if k = 0 && Id.Map.is_empty v then c else subst 0 c in
EConstr.of_constr c
type ext_named_context =
csubst * Id.Set.t * EConstr.named_context
let push_var id { csubst_len = n; csubst_var = v; csubst_rel = s; csubst_rev = r } =
let s = Int.Map.add n (Constr.mkVar id) s in
let r = Id.Map.add id (SRel n) r in
{ csubst_len = succ n; csubst_var = v; csubst_rel = s; csubst_rev = r }
(** Post-compose the substitution with the generator [src ↦ tgt] *)
let update_var src tgt subst =
let cur =
try Some (Id.Map.find src subst.csubst_rev)
with Not_found -> None
in
match cur with
| None ->
(* Missing keys stand for identity substitution [src ↦ src] *)
let csubst_var = Id.Map.add src (Constr.mkVar tgt) subst.csubst_var in
let csubst_rev = Id.Map.add tgt (SVar src) subst.csubst_rev in
{ subst with csubst_var; csubst_rev }
| Some bnd ->
let csubst_rev = Id.Map.add tgt bnd (Id.Map.remove src subst.csubst_rev) in
match bnd with
| SRel m ->
let csubst_rel = Int.Map.add m (Constr.mkVar tgt) subst.csubst_rel in
{ subst with csubst_rel; csubst_rev }
| SVar id ->
let csubst_var = Id.Map.add id (Constr.mkVar tgt) subst.csubst_var in
{ subst with csubst_var; csubst_rev }
type naming_mode =
| KeepUserNameAndRenameExistingButSectionNames
| KeepUserNameAndRenameExistingEvenSectionNames
| KeepExistingNames
| FailIfConflict
| ProgramNaming
let push_rel_decl_to_named_context
?(hypnaming=KeepUserNameAndRenameExistingButSectionNames)
sigma decl (subst, avoid, nc) =
let open EConstr in
let open Vars in
let map_decl f d =
NamedDecl.map_constr f d
in
let rec replace_var_named_declaration id0 id = function
| [] -> []
| decl :: nc ->
if Id.equal id0 (NamedDecl.get_id decl) then
(* Stop here, the variable cannot occur before its definition *)
(NamedDecl.set_id id decl) :: nc
else
let nc = replace_var_named_declaration id0 id nc in
let vsubst = [id0 , mkVar id] in
map_decl (fun c -> replace_vars vsubst c) decl :: nc
in
let extract_if_neq id = function
| Anonymous -> None
| Name id' when Id.compare id id' = 0 -> None
| Name id' -> Some id'
in
let na = RelDecl.get_name decl in
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 hypnaming = ProgramNaming then next_name_away na avoid
else
(* id_of_name_using_hdchar only depends on the rel context which is empty
here *)
next_ident_away (id_of_name_using_hdchar empty_env sigma (RelDecl.get_type decl) na) avoid
in
match extract_if_neq id na with
| Some id0 when hypnaming = KeepUserNameAndRenameExistingEvenSectionNames ||
(hypnaming = KeepUserNameAndRenameExistingButSectionNames ||
hypnaming = ProgramNaming) &&
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 = update_var id0 id subst in
let d = decl |> NamedDecl.of_rel_decl (fun _ -> id0) |> map_decl (csubst_subst subst) in
let nc = replace_var_named_declaration id0 id nc in
(push_var id0 subst, Id.Set.add id avoid, d :: nc)
| Some id0 when hypnaming = FailIfConflict ->
user_err Pp.(Id.print id0 ++ str " is already used.")
| _ ->
(* 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 = decl |> NamedDecl.of_rel_decl (fun _ -> id) |> map_decl (csubst_subst subst) in
(push_var id subst, Id.Set.add id avoid, d :: nc)
let push_rel_context_to_named_context ?hypnaming env sigma typ =
(* compute the instances relative to the named context and rel_context *)
let open Context.Named.Declaration in
let open EConstr in
let ids = List.map get_id (named_context env) in
let inst_vars = List.map mkVar ids in
if List.is_empty (Environ.rel_context env) then
(named_context_val env, typ, inst_vars, empty_csubst)
else
let avoid = List.fold_right Id.Set.add ids Id.Set.empty in
let inst_rels = List.rev (rel_list 0 (nb_rel env)) 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, _, env) =
Context.Rel.fold_outside (fun d acc -> push_rel_decl_to_named_context ?hypnaming sigma d acc)
(rel_context env) ~init:(empty_csubst, avoid, named_context env) in
(val_of_named_context env, csubst_subst subst typ, inst_rels@inst_vars, subst)
(*------------------------------------*
* Entry points to define new evars *
*------------------------------------*)
let default_source = Loc.tag @@ Evar_kinds.InternalHole
let new_pure_evar_full evd ?typeclass_candidate evi =
let (evd, evk) = Evd.new_evar evd ?typeclass_candidate evi in
let evd = Evd.declare_future_goal evk evd in
(evd, evk)
let new_pure_evar?(src=default_source) ?(filter = Filter.identity) ?(abstract_arguments = Abstraction.identity)
?candidates ?naming ?typeclass_candidate ?(principal=false) sign evd typ =
let default_naming = IntroAnonymous in
let naming = Option.default default_naming naming in
let name = match naming with
| IntroAnonymous -> None
| IntroIdentifier id -> Some id
| IntroFresh id ->
let has_name id = try let _ = Evd.evar_key id evd in true with Not_found -> false in
let id = Namegen.next_ident_away_from id has_name in
Some id
in
let evi = {
evar_hyps = sign;
evar_concl = typ;
evar_body = Evar_empty;
evar_filter = filter;
evar_abstract_arguments = abstract_arguments;
evar_source = src;
evar_candidates = candidates }
in
let typeclass_candidate = if principal then Some false else typeclass_candidate in
let (evd, newevk) = Evd.new_evar evd ?name ?typeclass_candidate evi 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 ?src ?filter ?abstract_arguments ?candidates ?naming ?typeclass_candidate
?principal sign evd typ instance =
let open EConstr in
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 ?abstract_arguments ?candidates ?naming ?typeclass_candidate ?principal typ in
evd, mkEvar (newevk,Array.of_list instance)
let new_evar_from_context ?src ?filter ?candidates ?naming ?typeclass_candidate ?principal sign evd typ =
let instance = List.map (NamedDecl.get_id %> EConstr.mkVar) (named_context_of_val sign) 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 ?naming ?principal 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 ?src ?filter ?abstract_arguments ?candidates ?naming ?typeclass_candidate
?principal ?hypnaming env evd typ =
let sign,typ',instance,subst = push_rel_context_to_named_context ?hypnaming env evd typ in
let map c = csubst_subst subst c in
let candidates = Option.map (fun l -> List.map map l) 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 ?abstract_arguments ?candidates ?naming
?typeclass_candidate ?principal instance
let new_type_evar ?src ?filter ?naming ?principal ?hypnaming env evd rigid =
let (evd', s) = new_sort_variable rigid evd in
let (evd', e) = new_evar env evd' ?src ?filter ?naming ~typeclass_candidate:false ?principal ?hypnaming (EConstr.mkSort s) in
evd', (e, s)
let new_Type ?(rigid=Evd.univ_flexible) evd =
let open EConstr in
let (evd, s) = new_sort_variable rigid evd in
(evd, mkSort s)
(* Safe interface to unification problems *)
type unification_pb = conv_pb * env * EConstr.constr * EConstr.constr
let eq_unification_pb evd (pbty,env,t1,t2) (pbty',env',t1',t2') =
pbty == pbty' && env == env' &&
EConstr.eq_constr evd t1 t1' &&
EConstr.eq_constr evd t2 t2'
let add_unification_pb ?(tail=false) pb evd =
let conv_pbs = Evd.conv_pbs evd in
if not (List.exists (eq_unification_pb evd pb) conv_pbs) then
let (pbty,env,t1,t2) = pb in
Evd.add_conv_pb ~tail (pbty,env,t1,t2) evd
else evd
(* 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 open EConstr in
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 sigma 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
| NoCandidatesLeft of Evar.t
exception ClearDependencyError of Id.t * clear_dependency_error * GlobRef.t option
exception Depends of Id.t
let set_of_evctx l =
List.fold_left (fun s decl -> Id.Set.add (NamedDecl.get_id decl) s) Id.Set.empty l
let filter_effective_candidates evd evi filter candidates =
let ids = set_of_evctx (Filter.filter_list filter (evar_context evi)) in
List.filter (fun a -> Id.Set.subset (collect_vars evd a) ids) candidates
let restrict_evar evd evk filter ?src candidates =
let evar_info = Evd.find_undefined evd evk in
let candidates = Option.map (filter_effective_candidates evd evar_info filter) candidates in
match candidates with
| Some [] -> raise (ClearDependencyError (*FIXME*)(Id.of_string "blah", (NoCandidatesLeft evk), None))
| _ ->
let evd, evk' = Evd.restrict evk filter ?candidates ?src evd in
(* Mark new evar as future goal, removing previous one,
circumventing Proofview.advance but making Proof.run_tactic catch these. *)
let future_goals = Evd.save_future_goals evd in
let future_goals = Evd.filter_future_goals (fun evk' -> not (Evar.equal evk evk')) future_goals in
let evd = Evd.restore_future_goals evd future_goals in
(Evd.declare_future_goal evk' evd, evk')
let rec check_and_clear_in_constr env evdref err ids global c =
(* returns a new constr where all the evars have been 'cleaned'
(ie the hypotheses ids have been removed from the contexts of
evars). [global] should be true iff there is some variable of [ids] which
is a section variable *)
match kind c with
| Var id' ->
if Id.Set.mem id' ids then raise (ClearDependencyError (id', err, None)) else c
| ( Const _ | Ind _ | Construct _ ) ->
let () = if global then
let check id' =
if Id.Set.mem id' ids then
raise (ClearDependencyError (id',err,Some (Globnames.global_of_constr c)))
in
Id.Set.iter check (Environ.vars_of_global env (fst @@ destRef c))
in
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 = Evd.existential_value !evdref (EConstr.of_existential ev) in
let nc = EConstr.Unsafe.to_constr nc in
(check_and_clear_in_constr env evdref err ids global 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 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 !evdref (EConstr.of_constr 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 env !evdref 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 (NamedDecl.get_id h) 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
let global = Id.Set.exists is_section_variable nids in
let concl = EConstr.Unsafe.to_constr (evar_concl evi) in
check_and_clear_in_constr env evdref (EvarTypingBreak ev) nids global concl
with ClearDependencyError (rid,err,where) ->
raise (ClearDependencyError (Id.Map.find rid rids,err,where)) 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 = !evdref in
let candidates = Evd.evar_candidates evi in
let candidates = Option.map (List.map EConstr.of_constr) candidates in
let (evd,_) = restrict_evar evd evk filter candidates in
evdref := evd;
Evd.existential_value0 !evdref ev
| _ -> Constr.map (check_and_clear_in_constr env evdref err ids global) c
let clear_hyps_in_evi_main env sigma 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 evdref = ref sigma in
let terms = List.map EConstr.Unsafe.to_constr terms in
let global = Id.Set.exists is_section_variable ids in
let terms =
List.map (check_and_clear_in_constr env evdref (OccurHypInSimpleClause None) ids global) terms in
let nhyps =
let check_context decl =
let err = OccurHypInSimpleClause (Some (NamedDecl.get_id decl)) in
NamedDecl.map_constr (check_and_clear_in_constr env evdref err ids global) decl
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
(!evdref, nhyps,List.map EConstr.of_constr terms)
let clear_hyps_in_evi env sigma hyps concl ids =
match clear_hyps_in_evi_main env sigma hyps [concl] ids with
| (sigma,nhyps,[nconcl]) -> (sigma,nhyps,nconcl)
| _ -> assert false
let clear_hyps2_in_evi env sigma hyps t concl ids =
match clear_hyps_in_evi_main env sigma hyps [t;concl] ids with
| (sigma,nhyps,[t;nconcl]) -> (sigma,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 (EConstr.Unsafe.to_constr 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 decl ->
let open NamedDecl in
queue_term q true (NamedDecl.get_type decl);
match decl with
| LocalAssum _ -> ()
| LocalDef (_,b,_) -> queue_term q true b
end (EConstr.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 (EConstr.Unsafe.to_constr 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 *)
(** [advance sigma g] returns [Some g'] if [g'] is undefined and is
the current avatar of [g] (for instance [g] was changed by [clear]
into [g']). It returns [None] if [g] has been (partially)
solved. *)
(* spiwack: [advance] is probably performance critical, and the good
behaviour of its definition may depend sensitively to the actual
definition of [Evd.find]. Currently, [Evd.find] starts looking for
a value in the heap of undefined variable, which is small. Hence in
the most common case, where [advance] is applied to an unsolved
goal ([advance] is used to figure if a side effect has modified the
goal) it terminates quickly. *)
let rec advance sigma evk =
let evi = Evd.find sigma evk in
match evi.evar_body with
| Evar_empty -> Some evk
| Evar_defined v ->
match is_restricted_evar sigma evk with
| Some evk -> advance sigma evk
| None -> None
(** 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 EConstr.kind evd c with
| Evar (n, l) ->
let acc = Evar.Set.add n acc in
Array.fold_left evrec acc l
| _ -> EConstr.fold evd evrec acc c
in
evrec Evar.Set.empty t
let undefined_evars_of_named_context evd nc =
Context.Named.fold_outside
(NamedDecl.fold_constr (fun c s -> Evar.Set.union s (undefined_evars_of_term evd (EConstr.of_constr c))))
nc
~init: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)))
type undefined_evars_cache = {
mutable cache : (EConstr.named_declaration * Evar.Set.t) ref Id.Map.t;
}
let create_undefined_evars_cache () = { cache = Id.Map.empty; }
let cached_evar_of_hyp cache sigma decl accu = match cache with
| None ->
let fold c acc =
let evs = undefined_evars_of_term sigma c in
Evar.Set.union evs acc
in
NamedDecl.fold_constr fold decl accu
| Some cache ->
let id = NamedDecl.get_annot decl in
let r =
try Id.Map.find id.binder_name cache.cache
with Not_found ->
(* Dummy value *)
let r = ref (NamedDecl.LocalAssum (id, EConstr.mkProp), Evar.Set.empty) in
let () = cache.cache <- Id.Map.add id.binder_name r cache.cache in
r
in
let (decl', evs) = !r in
let evs =
if NamedDecl.equal (==) decl decl' then snd !r
else
let fold c acc =
let evs = undefined_evars_of_term sigma c in
Evar.Set.union evs acc
in
let evs = NamedDecl.fold_constr fold decl Evar.Set.empty in
let () = r := (decl, evs) in
evs
in
Evar.Set.fold Evar.Set.add evs accu
let filtered_undefined_evars_of_evar_info ?cache sigma evi =
let evars_of_named_context cache accu nc =
let fold decl accu = cached_evar_of_hyp cache sigma (EConstr.of_named_decl decl) accu in
Context.Named.fold_outside fold nc ~init:accu
in
let accu = match evi.evar_body with
| Evar_empty -> Evar.Set.empty
| Evar_defined b -> evars_of_term (EConstr.Unsafe.to_constr b)
in
let accu = Evar.Set.union (undefined_evars_of_term sigma evi.evar_concl) accu in
let ctxt = EConstr.Unsafe.to_named_context (evar_filtered_context evi) in
evars_of_named_context cache accu ctxt
(* 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 c = EConstr.Unsafe.to_constr c in
let rec occur_rec c = match kind c with
| Evar (sp,_) when Evar.equal sp n -> raise Occur
| Evar e -> Option.iter occur_rec (existential_opt_value0 sigma e)
| _ -> Constr.iter occur_rec c
in
try occur_rec c; false with Occur -> true
(* 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 open EConstr in
let (evd', s) = new_univ_variable univ_rigid evd in
(evd', { uj_val = mkType s; uj_type = mkType (Univ.super s) })
let subterm_source evk ?where (loc,k) =
let evk = match k with
| Evar_kinds.SubEvar (None,evk) when where = None -> evk
| _ -> evk in
(loc,Evar_kinds.SubEvar (where,evk))
(* Add equality constraints for covariant/invariant positions. For
irrelevant positions, unify universes when flexible. *)
let compare_cumulative_instances cv_pb variances u u' sigma =
let open UnivProblem in
let cstrs = Univ.Constraint.empty in
let soft = Set.empty in
let cstrs, soft = Array.fold_left3 (fun (cstrs, soft) v u u' ->
let open Univ.Variance in
match v with
| Irrelevant -> cstrs, Set.add (UWeak (u,u')) soft
| Covariant when cv_pb == Reduction.CUMUL ->
Univ.Constraint.add (u,Univ.Le,u') cstrs, soft
| Covariant | Invariant -> Univ.Constraint.add (u,Univ.Eq,u') cstrs, soft)
(cstrs,soft) variances (Univ.Instance.to_array u) (Univ.Instance.to_array u')
in
match Evd.add_constraints sigma cstrs with
| sigma ->
Inl (Evd.add_universe_constraints sigma soft)
| exception Univ.UniverseInconsistency p -> Inr p
let compare_constructor_instances evd u u' =
let open UnivProblem in
let soft =
Array.fold_left2 (fun cs u u' -> Set.add (UWeak (u,u')) cs)
Set.empty (Univ.Instance.to_array u) (Univ.Instance.to_array u')
in
Evd.add_universe_constraints evd soft
(** [eq_constr_univs_test ~evd ~extended_evd t u] tests equality of
[t] and [u] up to existential variable instantiation and
equalisable universes. The term [t] is interpreted in [evd] while
[u] is interpreted in [extended_evd]. The universe constraints in
[extended_evd] are assumed to be an extension of those in [evd]. *)
let eq_constr_univs_test ~evd ~extended_evd t u =
(* spiwack: mild code duplication with {!Evd.eq_constr_univs}. *)
let open Evd in
let t = EConstr.Unsafe.to_constr t
and u = EConstr.Unsafe.to_constr u in
let fold cstr sigma =
try Some (add_universe_constraints sigma cstr)
with Univ.UniverseInconsistency _ | UniversesDiffer -> None
in
let ans =
UnivProblem.eq_constr_univs_infer_with
(fun t -> kind_of_term_upto evd t)
(fun u -> kind_of_term_upto extended_evd u)
(universes extended_evd) fold t u extended_evd
in
match ans with None -> false | Some _ -> true
¤ Dauer der Verarbeitung: 0.39 Sekunden
(vorverarbeitet)
¤
|
Haftungshinweis
Die Informationen auf dieser Webseite wurden
nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit,
noch Qualität der bereit gestellten Informationen zugesichert.
Bemerkung:
Die farbliche Syntaxdarstellung ist noch experimentell.
|
