(************************************************************************)
(*         *   The Coq Proof Assistant / The Coq Development Team       *)
(*  v      *         Copyright INRIA, CNRS and contributors             *)
(* <O___,, * (see version control and CREDITS file for authors & dates) *)
(*   \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 UVars
open Declarations
open Environ
open CClosure

(** {6 Extracting an inductive type from a construction } *)

(** [find_m*type env sigma c] coerce [c] to an recursive type (I args).
   [find_rectype], [find_inductive] and [find_coinductive]
   respectively accepts any recursive type, only an inductive type and
   only a coinductive type.
   They raise [Not_found] if not convertible to a recursive type. *)

val find_rectype     : ?evars:evar_handler -> env -> types -> pinductive * constr list
val find_inductive   : ?evars:evar_handler -> env -> types -> pinductive * constr list
val find_coinductive : ?evars:evar_handler -> env -> types -> pinductive * constr list

(** {6 ... } *)
(** Fetching information in the environment about an inductive type.
    Raises an anomaly if the inductive type is not found. *)
val lookup_mind_specif : env -> inductive -> mind_specif

(** {6 Functions to build standard types related to inductive } *)

(** Returns the parameters of an inductive type with universes instantiated *)
val inductive_paramdecls : mutual_inductive_body puniverses -> Constr.rel_context

(** Returns the parameters of an inductive type with universes
    instantiated, splitting it into the contexts of recursively
    uniform and recursively non-uniform parameters *)
val inductive_nonrec_rec_paramdecls : mutual_inductive_body puniverses -> Constr.rel_context * Constr.rel_context

val instantiate_inductive_constraints :
  mutual_inductive_body -> Instance.t -> Constraints.t

type template_univ =
  | TemplateProp
  | TemplateUniv of Universe.t

type param_univs = (expected:Univ.Level.t -> template_univ) list

val constrained_type_of_inductive : mind_specif puniverses -> types constrained
val constrained_type_of_inductive_knowing_parameters :
  mind_specif puniverses -> param_univs -> types constrained

val relevance_of_ind_body : one_inductive_body -> UVars.Instance.t -> Sorts.relevance

val relevance_of_inductive : env -> pinductive -> Sorts.relevance

val type_of_inductive : mind_specif puniverses -> types

val type_of_inductive_knowing_parameters :
  ?polyprop:bool -> mind_specif puniverses -> param_univs -> types

val quality_leq : Sorts.Quality.t -> Sorts.Quality.t -> bool
(** For squashing. *)

type squash = SquashToSet | SquashToQuality of Sorts.Quality.t

val is_squashed : mind_specif puniverses -> squash option

val is_allowed_elimination : mind_specif puniverses -> Sorts.t -> bool

val is_private : mind_specif -> bool
val is_primitive_record : mind_specif -> bool

(** Return type as quoted by the user *)

val constrained_type_of_constructor : pconstructor -> mind_specif -> types constrained
val type_of_constructor : pconstructor -> mind_specif -> types

(** Return constructor types in normal form *)
val arities_of_constructors : pinductive -> mind_specif -> types array

(** Return constructor types in user form *)
val type_of_constructors : pinductive -> mind_specif -> types array

(** Turns a constructor type recursively referring to inductive types
    into the same constructor type referring instead to a context made
    from the abstract declaration of the inductive types (e.g. turns
    [nat->nat] into [mkArrowR (Rel 1) (Rel 2)]); takes as arguments the number
    of inductive types in the block and the name of the block *)
val abstract_constructor_type_relatively_to_inductive_types_context :
  int -> MutInd.t -> types -> types

val inductive_params : mind_specif -> int

(** Given an inductive type and its parameters, builds the context of the return
    clause, including the inductive being eliminated. The additional binder
    array is only used to set the names of the context variables, we use the
    less general type to make it easy to use this function on Case nodes. *)
val expand_arity : mind_specif -> pinductive -> constr array ->
  Name.t binder_annot array -> rel_context

(** Given an inductive type and its parameters, builds the context of the return
    clause, including the inductive being eliminated. The additional binder
    array is only used to set the names of the context variables, we use the
    less general type to make it easy to use this function on Case nodes. *)
val expand_branch_contexts : mind_specif -> UVars.Instance.t -> constr array ->
  (Name.t binder_annot array * 'a) array -> rel_context array

type ('constr,'types,'r) pexpanded_case =
  (case_info * ('constr * 'r) * 'constr pcase_invert * 'constr * 'constr array)

type expanded_case = (constr,types,Sorts.relevance) pexpanded_case

(** Given a pattern-matching represented compactly, expands it so as to produce
    lambda and let abstractions in front of the return clause and the pattern
    branches. *)
val expand_case : env -> case -> expanded_case

val expand_case_specif : mutual_inductive_body -> case -> expanded_case

(** Dual operation of the above. Fails if the return clause or branch has not
    the expected form. *)
val contract_case : env -> expanded_case -> case

(** [instantiate_context u subst nas ctx] applies both [u] and [subst]
    to [ctx] while replacing names using [nas] (order reversed). In particular,
    assumes that [ctx] and [nas] have the same length. *)
val instantiate_context : Instance.t -> Vars.substl -> Name.t binder_annot array ->
  rel_context -> rel_context

val build_branches_type :
  pinductive -> mutual_inductive_body * one_inductive_body ->
    constr list -> constr -> types array

(** Check a [case_info] actually correspond to a Case expression on the
   given inductive type. *)
val check_case_info : env -> pinductive -> case_info -> unit

(** {6 Guard conditions for fix and cofix-points. } *)

(** [is_primitive_positive_container env c] tells if the constant [c] is
    registered as a primitive type that can be seen as a container where the
    occurrences of its parameters are positive, in which case the positivity and
    guard conditions are extended to allow inductive types to nest their subterms
    in these containers. *)
val is_primitive_positive_container : env -> Constant.t -> bool

(** When [chk] is false, the guard condition is not actually
    checked. *)
val check_fix : ?evars:evar_handler -> env -> fixpoint -> unit
val check_cofix : ?evars:evar_handler -> env -> cofixpoint -> unit

(** {6 Support for sort-polymorphic inductive types } *)

(** The "polyprop" optional argument below controls
    the "Prop-polymorphism". By default, it is allowed.
    But when "polyprop=false", the following exception is raised
    when a polymorphic singleton inductive type becomes Prop due to
    parameter instantiation. This is used by the Ocaml extraction,
    which cannot handle (yet?) Prop-polymorphism. *)

exception SingletonInductiveBecomesProp of Id.t

val abstract_mind_lc : int -> int -> MutInd.t -> (rel_context * constr) array -> constr array
