(************************************************************************)
(*         *   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 Names
open Constr
open Univ
open Declarations

(** Unsafe environments. We define here a datatype for environments.
   Since typing is not yet defined, it is not possible to check the
   informations added in environments, and that is why we speak here
   of ``unsafe'' environments. *)

(** Environments have the following components:
   - a context for de Bruijn variables
   - a context for de Bruijn variables vm values
   - a context for section variables and goal assumptions
   - a context for section variables and goal assumptions vm values
   - a context for global constants and axioms
   - a context for inductive definitions
   - a set of universe constraints
   - a flag telling if Set is, can be, or cannot be set impredicative *)

type lazy_val

val build_lazy_val : lazy_val -> (Vmvalues.values * Id.Set.t) -> unit
val force_lazy_val : lazy_val -> (Vmvalues.values * Id.Set.t) option
val dummy_lazy_val : unit -> lazy_val

(** Linking information for the native compiler *)
type link_info =
  | Linked of string
  | LinkedInteractive of string
  | NotLinked

type key = int CEphemeron.key option ref

type constant_key = constant_body * (link_info ref * key)

type mind_key = mutual_inductive_body * link_info ref

type globals
(** globals = constants + projections + inductive types + modules + module-types *)

type stratification = {
  env_universes : UGraph.t;
  env_engagement : engagement;
  env_sprop_allowed : bool;
}

type named_context_val = private {
  env_named_ctx : Constr.named_context;
  env_named_map : (Constr.named_declaration * lazy_val) Id.Map.t;
}

type rel_context_val = private {
  env_rel_ctx : Constr.rel_context;
  env_rel_map : (Constr.rel_declaration * lazy_val) Range.t;
}

type env = private {
  env_globals       : globals;
  env_named_context : named_context_val; (* section variables *)
  env_rel_context   : rel_context_val;
  env_nb_rel        : int;
  env_stratification : stratification;
  env_typing_flags  : typing_flags;
  retroknowledge : Retroknowledge.retroknowledge;
  indirect_pterms : Opaqueproof.opaquetab;
}

val oracle : env -> Conv_oracle.oracle
val set_oracle : env -> Conv_oracle.oracle -> env

val eq_named_context_val : named_context_val -> named_context_val -> bool

val empty_env : env

val universes     : env -> UGraph.t
val rel_context   : env -> Constr.rel_context
val named_context : env -> Constr.named_context
val named_context_val : env -> named_context_val

val opaque_tables : env -> Opaqueproof.opaquetab
val set_opaque_tables : env -> Opaqueproof.opaquetab -> env


val engagement    : env -> engagement
val typing_flags    : env -> typing_flags
val is_impredicative_set : env -> bool
val type_in_type : env -> bool
val deactivated_guard : env -> bool
val indices_matter : env -> bool

val is_impredicative_sort : env -> Sorts.t -> bool
val is_impredicative_univ : env -> Univ.Universe.t -> bool

(** is the local context empty *)
val empty_context : env -> bool

(** {5 Context of de Bruijn variables ([rel_context]) } *)

val nb_rel           : env -> int
val push_rel         : Constr.rel_declaration -> env -> env
val push_rel_context : Constr.rel_context -> env -> env
val push_rec_types   : rec_declaration -> env -> env

(** Looks up in the context of local vars referred by indice ([rel_context]) 
   raises [Not_found] if the index points out of the context *)
val lookup_rel    : int -> env -> Constr.rel_declaration
val lookup_rel_val : int -> env -> lazy_val
val evaluable_rel : int -> env -> bool
val env_of_rel     : int -> env -> env

(** {6 Recurrence on [rel_context] } *)

val fold_rel_context :
  (env -> Constr.rel_declaration -> 'a -> 'a) -> env -> init:'a -> 'a

(** {5 Context of variables (section variables and goal assumptions) } *)

val named_context_of_val : named_context_val -> Constr.named_context
val val_of_named_context : Constr.named_context -> named_context_val
val empty_named_context_val : named_context_val
val ids_of_named_context_val : named_context_val -> Id.Set.t


(** [map_named_val f ctxt] apply [f] to the body and the type of
   each declarations.
   *** /!\ ***   [f t] should be convertible with t *)
val map_named_val :
   (constr -> constr) -> named_context_val -> named_context_val

val push_named : Constr.named_declaration -> env -> env
val push_named_context : Constr.named_context -> env -> env
val push_named_context_val  :
    Constr.named_declaration -> named_context_val -> named_context_val



(** Looks up in the context of local vars referred by names ([named_context]) 
   raises [Not_found] if the Id.t is not found *)

val lookup_named     : variable -> env -> Constr.named_declaration
val lookup_named_val : variable -> env -> lazy_val
val lookup_named_ctxt : variable -> named_context_val -> Constr.named_declaration
val evaluable_named  : variable -> env -> bool
val named_type : variable -> env -> types
val named_body : variable -> env -> constr option

(** {6 Recurrence on [named_context]: older declarations processed first } *)

val fold_named_context :
  (env -> Constr.named_declaration -> 'a -> 'a) -> env -> init:'a -> 'a

(** Recurrence on [named_context] starting from younger decl *)
val fold_named_context_reverse :
  ('a -> Constr.named_declaration -> 'a) -> init:'a -> env -> 'a

(** This forgets named and rel contexts *)
val reset_context : env -> env

(** This forgets rel context and sets a new named context *)
val reset_with_named_context : named_context_val -> env -> env

(** This removes the [n] last declarations from the rel context *)
val pop_rel_context : int -> env -> env

(** Useful for printing *)
val fold_constants : (Constant.t -> constant_body -> 'a -> 'a) -> env -> 'a -> 'a

(** {5 Global constants }
  {6 Add entries to global environment } *)

val add_constant : Constant.t -> constant_body -> env -> env
val add_constant_key : Constant.t -> constant_body -> link_info ->
  env -> env
val lookup_constant_key :  Constant.t -> env -> constant_key

(** Looks up in the context of global constant names 
   raises [Not_found] if the required path is not found *)
val lookup_constant    : Constant.t -> env -> constant_body
val evaluable_constant : Constant.t -> env -> bool

(** New-style polymorphism *)
val polymorphic_constant  : Constant.t -> env -> bool
val polymorphic_pconstant : pconstant -> env -> bool
val type_in_type_constant : Constant.t -> env -> bool

(** {6 ... } *)
(** [constant_value env c] raises [NotEvaluableConst Opaque] if
   [c] is opaque, [NotEvaluableConst NoBody] if it has no
   body, [NotEvaluableConst IsProj] if [c] is a projection,
   [NotEvaluableConst (IsPrimitive p)] if [c] is primitive [p]
   and [Not_found] if it does not exist in [env] *)

type const_evaluation_result =
  | NoBody
  | Opaque
  | IsPrimitive of CPrimitives.t
exception NotEvaluableConst of const_evaluation_result

val constant_type : env -> Constant.t puniverses -> types constrained

val constant_value_and_type : env -> Constant.t puniverses -> 
  constr option * types * Univ.Constraint.t
(** The universe context associated to the constant, empty if not 
    polymorphic *)
val constant_context : env -> Constant.t -> Univ.AUContext.t

(** Returns the body of the constant if it has any, and the polymorphic context
    it lives in. For monomorphic constant, the latter is empty, and for
    polymorphic constants, the term contains De Bruijn universe variables that
    need to be instantiated. *)
val body_of_constant_body : env -> constant_body -> (Constr.constr * Univ.AUContext.t) option

(* These functions should be called under the invariant that [env] 
   already contains the constraints corresponding to the constant 
   application. *)
val constant_value_in : env -> Constant.t puniverses -> constr
val constant_type_in : env -> Constant.t puniverses -> types
val constant_opt_value_in : env -> Constant.t puniverses -> constr option

val is_primitive : env -> Constant.t -> bool

(** {6 Primitive projections} *)

(** Checks that the number of parameters is correct. *)
val lookup_projection : Names.Projection.t -> env -> types

val get_projection : env -> inductive -> proj_arg:int -> Names.Projection.Repr.t option
val get_projections : env -> inductive -> Names.Projection.Repr.t array option

(** {5 Inductive types } *)
val lookup_mind_key : MutInd.t -> env -> mind_key
val add_mind_key : MutInd.t -> mind_key -> env -> env
val add_mind : MutInd.t -> mutual_inductive_body -> env -> env

(** Looks up in the context of global inductive names 
   raises [Not_found] if the required path is not found *)
val lookup_mind : MutInd.t -> env -> mutual_inductive_body

(** The universe context associated to the inductive, empty if not
    polymorphic *)
val mind_context : env -> MutInd.t -> Univ.AUContext.t

(** New-style polymorphism *)
val polymorphic_ind  : inductive -> env -> bool
val polymorphic_pind : pinductive -> env -> bool
val type_in_type_ind : inductive -> env -> bool

(** Old-style polymorphism *)
val template_polymorphic_ind : inductive -> env -> bool
val template_polymorphic_pind : pinductive -> env -> bool

(** {5 Modules } *)

val add_modtype : module_type_body -> env -> env

(** [shallow_add_module] does not add module components *)
val shallow_add_module : module_body -> env -> env

val lookup_module : ModPath.t -> env -> module_body
val lookup_modtype : ModPath.t -> env -> module_type_body

(** {5 Universe constraints } *)

(** Add universe constraints to the environment.
    @raise UniverseInconsistency .
*)
val add_constraints : Univ.Constraint.t -> env -> env

(** Check constraints are satifiable in the environment. *)
val check_constraints : Univ.Constraint.t -> env -> bool
val push_context : ?strict:bool -> Univ.UContext.t -> env -> env
val push_context_set : ?strict:bool -> Univ.ContextSet.t -> env -> env
val push_constraints_to_env : 'a Univ.constrained -> env -> env

val push_subgraph : Univ.ContextSet.t -> env -> env
(** [push_subgraph univs env] adds the universes and constraints in
   [univs] to [env] as [push_context_set ~strict:false univs env], and
   also checks that they do not imply new transitive constraints
   between pre-existing universes in [env]. *)

val set_engagement : engagement -> env -> env
val set_typing_flags : typing_flags -> env -> env
val make_sprop_cumulative : env -> env
val set_allow_sprop : bool -> env -> env
val sprop_allowed : env -> bool

val universes_of_global : env -> GlobRef.t -> AUContext.t

(** {6 Sets of referred section variables }
   [global_vars_set env c] returns the list of [id]'s occurring either
   directly as [Var id] in [c] or indirectly as a section variable
   dependent in a global reference occurring in [c] *)

val global_vars_set : env -> constr -> Id.Set.t

val vars_of_global : env -> GlobRef.t -> Id.Set.t

(** closure of the input id set w.r.t. dependency *)
val really_needed : env -> Id.Set.t -> Id.Set.t

(** like [really_needed] but computes a well ordered named context *)
val keep_hyps : env -> Id.Set.t -> Constr.named_context

(** {5 Unsafe judgments. }
    We introduce here the pre-type of judgments, which is
  actually only a datatype to store a term with its type and the type of its
  type. *)

type ('constr, 'types) punsafe_judgment = {
  uj_val : 'constr;
  uj_type : 'types }

val on_judgment       : ('a -> 'b) -> ('a, 'a) punsafe_judgment -> ('b, 'b) punsafe_judgment
val on_judgment_value : ('c -> 'c) -> ('c, 't) punsafe_judgment -> ('c, 't) punsafe_judgment
val on_judgment_type  : ('t -> 't) -> ('c, 't) punsafe_judgment -> ('c, 't) punsafe_judgment

type unsafe_judgment = (constr, types) punsafe_judgment

val make_judge : 'constr -> 'types -> ('constr, 'types) punsafe_judgment
val j_val  : ('constr, 'types) punsafe_judgment -> 'constr
val j_type : ('constr, 'types) punsafe_judgment -> 'types

type 'types punsafe_type_judgment = {
  utj_val : 'types;
  utj_type : Sorts.t }

type unsafe_type_judgment = types punsafe_type_judgment

exception Hyp_not_found

(** [apply_to_hyp sign id f] split [sign] into [tail::(id,_,_)::head] and
   return [tail::(f head (id,_,_) (rev tail))::head].
   the value associated to id should not change *)
val apply_to_hyp : named_context_val -> variable ->
  (Constr.named_context -> Constr.named_declaration -> Constr.named_context -> Constr.named_declaration) ->
    named_context_val

val remove_hyps : Id.Set.t -> (Constr.named_declaration -> Constr.named_declaration) -> (lazy_val -> lazy_val) -> named_context_val -> named_context_val

val is_polymorphic : env -> Names.GlobRef.t -> bool
val is_template_polymorphic : env -> GlobRef.t -> bool
val is_type_in_type : env -> GlobRef.t -> bool

(** Native compiler *)
val no_link_info : link_info

(** Primitives *)
val set_retroknowledge : env -> Retroknowledge.retroknowledge -> env