(***********************************************************************)
(*                                                                     *)
(*                                OCaml                                *)
(*                                                                     *)
(*            Xavier Leroy, projet Cristal, INRIA Rocquencourt         *)
(*                                                                     *)
(*  Copyright 1996 Institut National de Recherche en Informatique et   *)
(*  en Automatique.  All rights reserved.  This file is distributed    *)
(*  under the terms of the Q Public License version 1.0.               *)
(*                                                                     *)
(***********************************************************************)

(* Abstract syntax tree after typing *)

open Misc
open Asttypes
open Types

(* Value expressions for the core language *)

type partial = Partial | Total
type optional = Required | Optional

type attribute = string * Parsetree.expression

type pattern =
  { pat_desc: pattern_desc;
    pat_loc: Location.t;
    pat_extra : (pat_extra * Location.t * attribute list) list;
    pat_type: type_expr;
    mutable pat_env: Env.t;
    pat_attributes: attribute list;
   }

and pat_extra =
  | Tpat_constraint of core_type
  | Tpat_type of Path.t * Longident.t loc
  | Tpat_unpack

and pattern_desc =
    Tpat_any
  | Tpat_var of Ident.t * string loc
  | Tpat_alias of pattern * Ident.t * string loc
  | Tpat_constant of constant
  | Tpat_tuple of pattern list
  | Tpat_construct of
      Longident.t loc * constructor_description * pattern list * bool
  | Tpat_variant of label * pattern option * row_desc ref
  | Tpat_record of
      (Longident.t loc * label_description * pattern) list *
        closed_flag
  | Tpat_array of pattern list
  | Tpat_or of pattern * pattern * row_desc option
  | Tpat_lazy of pattern

and expression =
  { exp_desc: expression_desc;
    exp_loc: Location.t;
    exp_extra: (exp_extra * Location.t * attribute list) list;
    exp_type: type_expr;
    exp_env: Env.t;
    exp_attributes: attribute list;
   }

and exp_extra =
  | Texp_constraint of core_type option * core_type option
  | Texp_open of Path.t * Longident.t loc * Env.t
  | Texp_poly of core_type option
  | Texp_newtype of string

and expression_desc =
    Texp_ident of Path.t * Longident.t loc * Types.value_description
  | Texp_constant of constant
  | Texp_let of rec_flag * (pattern * expression) list * expression
  | Texp_function of label * (pattern * expression) list * partial
  | Texp_apply of expression * (label * expression option * optional) list
  | Texp_match of expression * (pattern * expression) list * partial
  | Texp_try of expression * (pattern * expression) list
  | Texp_tuple of expression list
  | Texp_construct of
      Longident.t loc * constructor_description * expression list *
        bool
  | Texp_variant of label * expression option
  | Texp_record of
      (Longident.t loc * label_description * expression) list *
        expression option
  | Texp_field of expression * Longident.t loc * label_description
  | Texp_setfield of
      expression * Longident.t loc * label_description * expression
  | Texp_array of expression list
  | Texp_ifthenelse of expression * expression * expression option
  | Texp_sequence of expression * expression
  | Texp_while of expression * expression
  | Texp_for of
      Ident.t * string loc * expression * expression * direction_flag *
        expression
  | Texp_when of expression * expression
  | Texp_send of expression * meth * expression option
  | Texp_new of Path.t * Longident.t loc * Types.class_declaration
  | Texp_instvar of Path.t * Path.t * string loc
  | Texp_setinstvar of Path.t * Path.t * string loc * expression
  | Texp_override of Path.t * (Path.t * string loc * expression) list
  | Texp_letmodule of Ident.t * string loc * module_expr * expression
  | Texp_assert of expression
  | Texp_assertfalse
  | Texp_lazy of expression
  | Texp_object of class_structure * string list
  | Texp_pack of module_expr

and meth =
    Tmeth_name of string
  | Tmeth_val of Ident.t

(* Value expressions for the class language *)

and class_expr =
  { cl_desc: class_expr_desc;
    cl_loc: Location.t;
    cl_type: Types.class_type;
    cl_env: Env.t }

and class_expr_desc =
    Tcl_ident of Path.t * Longident.t loc * core_type list
  | Tcl_structure of class_structure
  | Tcl_fun of
      label * pattern * (Ident.t * string loc * expression) list * class_expr *
        partial
  | Tcl_apply of class_expr * (label * expression option * optional) list
  | Tcl_let of rec_flag *  (pattern * expression) list *
                  (Ident.t * string loc * expression) list * class_expr
  | Tcl_constraint of
      class_expr * class_type option * string list * string list * Concr.t
    (* Visible instance variables, methods and concretes methods *)

and class_structure =
  { cstr_pat : pattern;
    cstr_fields: class_field list;
    cstr_type : Types.class_signature;
    cstr_meths: Ident.t Meths.t }

and class_field =
   {
    cf_desc : class_field_desc;
    cf_loc : Location.t;
  }

and class_field_kind =
  Tcfk_virtual of core_type
| Tcfk_concrete of expression

and class_field_desc =
    Tcf_inher of
      override_flag * class_expr * string option * (string * Ident.t) list *
        (string * Ident.t) list
    (* Inherited instance variables and concrete methods *)
  | Tcf_val of
      string * string loc * mutable_flag * Ident.t * class_field_kind * bool
        (* None = virtual, true = override *)
  | Tcf_meth of string * string loc * private_flag * class_field_kind * bool
  | Tcf_constr of core_type * core_type
(*  | Tcf_let of rec_flag * (pattern * expression) list *
              (Ident.t * string loc * expression) list *)
  | Tcf_init of expression

(* Value expressions for the module language *)

and module_expr =
  { mod_desc: module_expr_desc;
    mod_loc: Location.t;
    mod_type: Types.module_type;
    mod_env: Env.t;
    mod_attributes: attribute list;
   }

and module_type_constraint =
  Tmodtype_implicit
| Tmodtype_explicit of module_type

and module_expr_desc =
    Tmod_ident of Path.t * Longident.t loc
  | Tmod_structure of structure
  | Tmod_functor of Ident.t * string loc * module_type * module_expr
  | Tmod_apply of module_expr * module_expr * module_coercion
  | Tmod_constraint of
      module_expr * Types.module_type * module_type_constraint * module_coercion
  | Tmod_unpack of expression * Types.module_type

and structure = {
  str_items : structure_item list;
  str_type : Types.signature;
  str_final_env : Env.t;
}

and structure_item =
  { str_desc : structure_item_desc;
    str_loc : Location.t;
    str_env : Env.t
  }

and structure_item_desc =
    Tstr_eval of expression
  | Tstr_value of rec_flag * (pattern * expression) list
  | Tstr_primitive of value_description
  | Tstr_type of (Ident.t * string loc * type_declaration) list
  | Tstr_exception of Ident.t * string loc * exception_declaration
  | Tstr_exn_rebind of Ident.t * string loc * Path.t * Longident.t loc * attribute list
  | Tstr_module of Ident.t * string loc * module_expr
  | Tstr_recmodule of (Ident.t * string loc * module_type * module_expr) list
  | Tstr_modtype of Ident.t * string loc * module_type
  | Tstr_open of Path.t * Longident.t loc * attribute list
  | Tstr_class of (class_declaration * string list * virtual_flag) list
  | Tstr_class_type of (Ident.t * string loc * class_type_declaration) list
  | Tstr_include of module_expr * Ident.t list * attribute list
  | Tstr_attribute of attribute

and module_coercion =
    Tcoerce_none
  | Tcoerce_structure of (int * module_coercion) list
  | Tcoerce_functor of module_coercion * module_coercion
  | Tcoerce_primitive of Primitive.description

and module_type =
  { mty_desc: module_type_desc;
    mty_type : Types.module_type;
    mty_env : Env.t;
    mty_loc: Location.t;
    mty_attributes: attribute list;
   }

and module_type_desc =
    Tmty_ident of Path.t * Longident.t loc
  | Tmty_signature of signature
  | Tmty_functor of Ident.t * string loc * module_type * module_type
  | Tmty_with of module_type * (Path.t * Longident.t loc * with_constraint) list
  | Tmty_typeof of module_expr

and signature = {
  sig_items : signature_item list;
  sig_type : Types.signature;
  sig_final_env : Env.t;
}

and signature_item =
  { sig_desc: signature_item_desc;
    sig_env : Env.t; (* BINANNOT ADDED *)
    sig_loc: Location.t }

and signature_item_desc =
    Tsig_value of value_description
  | Tsig_type of (Ident.t * string loc * type_declaration) list
  | Tsig_exception of Ident.t * string loc * exception_declaration
  | Tsig_module of module_declaration
  | Tsig_recmodule of module_declaration list
  | Tsig_modtype of module_type_declaration
  | Tsig_open of Path.t * Longident.t loc * attribute list
  | Tsig_include of module_type * Types.signature * attribute list
  | Tsig_class of class_description list
  | Tsig_class_type of class_type_declaration list
  | Tsig_attribute of attribute

and module_declaration =
    {
     md_id: Ident.t;
     md_name: string loc;
     md_type: module_type;
     md_attributes: attribute list;
    }

and module_type_declaration =
    {
     mtd_id: Ident.t;
     mtd_name: string loc;
     mtd_type: module_type option;
     mtd_attributes: attribute list;
    }

and with_constraint =
    Twith_type of type_declaration
  | Twith_module of Path.t * Longident.t loc
  | Twith_typesubst of type_declaration
  | Twith_modsubst of Path.t * Longident.t loc

and core_type =
(* mutable because of [Typeclass.declare_method] *)
  { mutable ctyp_desc : core_type_desc;
    mutable ctyp_type : type_expr;
    ctyp_env : Env.t; (* BINANNOT ADDED *)
    ctyp_loc : Location.t;
    ctyp_attributes: attribute list;
   }

and core_type_desc =
    Ttyp_any
  | Ttyp_var of string
  | Ttyp_arrow of label * core_type * core_type
  | Ttyp_tuple of core_type list
  | Ttyp_constr of Path.t * Longident.t loc * core_type list
  | Ttyp_object of core_field_type list
  | Ttyp_class of Path.t * Longident.t loc * core_type list * label list
  | Ttyp_alias of core_type * string
  | Ttyp_variant of row_field list * bool * label list option
  | Ttyp_poly of string list * core_type
  | Ttyp_package of package_type

and package_type = {
  pack_name : Path.t;
  pack_fields : (Longident.t loc * core_type) list;
  pack_type : Types.module_type;
  pack_txt : Longident.t loc;
}

and core_field_type =
  { field_desc: core_field_desc;
    field_loc: Location.t }

and core_field_desc =
    Tcfield of string * core_type
  | Tcfield_var

and row_field =
    Ttag of label * bool * core_type list
  | Tinherit of core_type

and value_description =
  { val_id: Ident.t;
    val_name: string loc;
    val_desc: core_type;
    val_val: Types.value_description;
    val_prim: string list;
    val_loc: Location.t;
    val_attributes: attribute list;
    }

and type_declaration =
  { typ_params: string loc option list;
    typ_type : Types.type_declaration;
    typ_cstrs: (core_type * core_type * Location.t) list;
    typ_kind: type_kind;
    typ_private: private_flag;
    typ_manifest: core_type option;
    typ_variance: (bool * bool) list;
    typ_loc: Location.t;
    typ_attributes: attribute list;
   }

and type_kind =
    Ttype_abstract
  | Ttype_variant of constructor_declaration list
  | Ttype_record of label_declaration list

and label_declaration =
    {
     ld_id: Ident.t;
     ld_name: string loc;
     ld_mutable: mutable_flag;
     ld_type: core_type;
     ld_loc: Location.t;
     ld_attributes: attribute list;
    }

and constructor_declaration =
    {
     cd_id: Ident.t;
     cd_name: string loc;
     cd_args: core_type list;
     cd_res: core_type option;
     cd_loc: Location.t;
     cd_attributes: attribute list;
    }

and exception_declaration =
  { exn_params : core_type list;
    exn_exn : Types.exception_declaration;
    exn_loc : Location.t;
    exn_attributes: attribute list;
   }

and class_type =
  { cltyp_desc: class_type_desc;
    cltyp_type : Types.class_type;
    cltyp_env : Env.t; (* BINANNOT ADDED *)
    cltyp_loc: Location.t }

and class_type_desc =
    Tcty_constr of Path.t * Longident.t loc * core_type list
  | Tcty_signature of class_signature
  | Tcty_fun of label * core_type * class_type

and class_signature = {
    csig_self : core_type;
    csig_fields : class_type_field list;
    csig_type : Types.class_signature;
    csig_loc : Location.t;
  }

and class_type_field = {
    ctf_desc : class_type_field_desc;
    ctf_loc : Location.t;
  }

and class_type_field_desc =
    Tctf_inher of class_type
  | Tctf_val of (string * mutable_flag * virtual_flag * core_type)
  | Tctf_virt  of (string * private_flag * core_type)
  | Tctf_meth  of (string * private_flag * core_type)
  | Tctf_cstr  of (core_type * core_type)

and class_declaration =
  class_expr class_infos

and class_description =
  class_type class_infos

and class_type_declaration =
  class_type class_infos

and 'a class_infos =
  { ci_virt: virtual_flag;
    ci_params: string loc list * Location.t;
    ci_id_name : string loc;
    ci_id_class: Ident.t;
    ci_id_class_type : Ident.t;
    ci_id_object : Ident.t;
    ci_id_typesharp : Ident.t;
    ci_expr: 'a;
    ci_decl: Types.class_declaration;
    ci_type_decl : Types.class_type_declaration;
    ci_variance: (bool * bool) list;
    ci_loc: Location.t;
    ci_attributes: attribute list;
   }

(* Auxiliary functions over the a.s.t. *)

let iter_pattern_desc f = function
  | Tpat_alias(p, _, _) -> f p
  | Tpat_tuple patl -> List.iter f patl
  | Tpat_construct(_, cstr, patl, _) -> List.iter f patl
  | Tpat_variant(_, pat, _) -> may f pat
  | Tpat_record (lbl_pat_list, _) ->
      List.iter (fun (_, lbl, pat) -> f pat) lbl_pat_list
  | Tpat_array patl -> List.iter f patl
  | Tpat_or(p1, p2, _) -> f p1; f p2
  | Tpat_lazy p -> f p
  | Tpat_any
  | Tpat_var _
  | Tpat_constant _ -> ()

let map_pattern_desc f d =
  match d with
  | Tpat_alias (p1, id, s) ->
      Tpat_alias (f p1, id, s)
  | Tpat_tuple pats ->
      Tpat_tuple (List.map f pats)
  | Tpat_record (lpats, closed) ->
      Tpat_record (List.map (fun (lid, l,p) -> lid, l, f p) lpats, closed)
  | Tpat_construct (lid, c,pats, arity) ->
      Tpat_construct (lid, c, List.map f pats, arity)
  | Tpat_array pats ->
      Tpat_array (List.map f pats)
  | Tpat_lazy p1 -> Tpat_lazy (f p1)
  | Tpat_variant (x1, Some p1, x2) ->
      Tpat_variant (x1, Some (f p1), x2)
  | Tpat_or (p1,p2,path) ->
      Tpat_or (f p1, f p2, path)
  | Tpat_var _
  | Tpat_constant _
  | Tpat_any
  | Tpat_variant (_,None,_) -> d

(* List the identifiers bound by a pattern or a let *)

let idents = ref([]: (Ident.t * string loc) list)

let rec bound_idents pat =
  match pat.pat_desc with
  | Tpat_var (id,s) -> idents := (id,s) :: !idents
  | Tpat_alias(p, id, s ) ->
      bound_idents p; idents := (id,s) :: !idents
  | Tpat_or(p1, _, _) ->
      (* Invariant : both arguments binds the same variables *)
      bound_idents p1
  | d -> iter_pattern_desc bound_idents d

let pat_bound_idents pat =
  idents := []; bound_idents pat; let res = !idents in idents := []; res

let rev_let_bound_idents_with_loc pat_expr_list =
  idents := [];
  List.iter (fun (pat, expr) -> bound_idents pat) pat_expr_list;
  let res = !idents in idents := []; res

let let_bound_idents_with_loc pat_expr_list =
  List.rev(rev_let_bound_idents_with_loc pat_expr_list)

let rev_let_bound_idents pat = List.map fst (rev_let_bound_idents_with_loc pat)
let let_bound_idents pat = List.map  fst (let_bound_idents_with_loc pat)

let alpha_var env id = List.assoc id env

let rec alpha_pat env p = match p.pat_desc with
| Tpat_var (id, s) -> (* note the ``Not_found'' case *)
    {p with pat_desc =
     try Tpat_var (alpha_var env id, s) with
     | Not_found -> Tpat_any}
| Tpat_alias (p1, id, s) ->
    let new_p =  alpha_pat env p1 in
    begin try
      {p with pat_desc = Tpat_alias (new_p, alpha_var env id, s)}
    with
    | Not_found -> new_p
    end
| d ->
    {p with pat_desc = map_pattern_desc (alpha_pat env) d}

let mkloc = Location.mkloc
let mknoloc = Location.mknoloc