(************************************************************************)
(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
(* <O___,, * CNRS-Ecole Polytechnique-INRIA Futurs-Universite Paris Sud *)
(*   \VV/  **************************************************************)
(*    //   *      This file is distributed under the terms of the       *)
(*         *       GNU Lesser General Public License Version 2.1        *)
(************************************************************************)
(*i camlp4deps: "parsing/grammar.cma" i*)
open Term
open Names
open Pp
open Topconstr
open Indfun_common 
open Indfun
open Genarg

TACTIC EXTEND newfuninv
   [ "functional" "inversion" ident(hyp) ident(fname) ] -> 
     [
       Invfun.invfun hyp fname
     ]
END


let pr_fun_ind_using  prc _ _ opt_c = 
  match opt_c with 
    | None -> mt ()
    | Some c -> spc () ++ hov 2 (str "using" ++ spc () ++ prc c)

ARGUMENT EXTEND fun_ind_using
  TYPED AS constr_opt
  PRINTED BY pr_fun_ind_using
| [ "using" constr(c) ] -> [ Some c ]
| [ ] -> [ None ]
END

let pr_intro_as_pat prc _ _ pat = 
  str "as" ++ spc () ++ pr_intro_pattern pat





ARGUMENT EXTEND with_names TYPED AS intro_pattern PRINTED BY pr_intro_as_pat
|   [ "as"  simple_intropattern(ipat) ] -> [ ipat ] 
| []  ->[ IntroAnonymous ] 
END


let is_rec scheme_info = 
  let test_branche min acc (_,_,br) = 
    acc ||
      (let new_branche = Sign.it_mkProd_or_LetIn mkProp (fst (Sign.decompose_prod_assum br)) in 
      let free_rels_in_br = Termops.free_rels new_branche in 
      let max = min + scheme_info.Tactics.npredicates in 
      Util.Intset.exists (fun i -> i >= min && i< max) free_rels_in_br)
  in
  Util.list_fold_left_i test_branche 1 false (List.rev scheme_info.Tactics.branches)


let choose_dest_or_ind scheme_info =
    if is_rec scheme_info
    then Tactics.new_induct
    else
      Tactics.new_destruct


TACTIC EXTEND newfunind
   ["new" "functional" "induction" constr(c) fun_ind_using(princl) with_names(pat)] -> 
     [
       let f,args = decompose_app c in 
       fun g -> 
	 let princ = 
	   match princl with 
	     | None -> (* No principle is given let's find the good one *)
		 let fname = 
		   match kind_of_term f with 
		     | Const c' -> 
			 id_of_label (con_label c') 
		     | _ -> Util.error "Must be used with a function" 
		 in
		 let princ_name = 
		   (
		     Indrec.make_elimination_ident
		       fname
		       (Tacticals.elimination_sort_of_goal g)
		   )
		 in
		 mkConst(const_of_id princ_name )
	     | Some princ -> princ 
	 in
	 let princ_type = Tacmach.pf_type_of g princ in 
	 let princ_infos = Tactics.compute_elim_sig princ_type in 
	 let args_as_induction_constr =
	   let c_list = 
	     if princ_infos.Tactics.farg_in_concl 
	     then [c] else [] 
	   in
	   List.map (fun c -> Tacexpr.ElimOnConstr c) (args@c_list) 
	 in 
	 let princ' = Some (princ,Rawterm.NoBindings) in 
	 choose_dest_or_ind 
	   princ_infos
	   args_as_induction_constr
	   princ'
	   pat g
     ]
END


VERNAC ARGUMENT EXTEND rec_annotation2
  [ "{"  "struct" ident(id)  "}"] -> [ Struct id ]
| [ "{" "wf" constr(r) ident_opt(id) "}" ] -> [ Wf(r,id) ]
| [ "{" "mes" constr(r) ident_opt(id) "}" ] -> [ Mes(r,id) ] 
END


VERNAC ARGUMENT EXTEND binder2
    [ "(" ne_ident_list(idl) ":" lconstr(c)  ")"] ->
     [
       LocalRawAssum (List.map (fun id -> (Util.dummy_loc,Name id)) idl,c) ]
END


VERNAC ARGUMENT EXTEND rec_definition2
 [ ident(id)  binder2_list( bl)
     rec_annotation2_opt(annot) ":" lconstr( type_)
	":=" lconstr(def)] ->
    [let names = List.map snd (Topconstr.names_of_local_assums bl) in
     let check_one_name () =
       if List.length names > 1 then
         Util.user_err_loc
           (Util.dummy_loc,"GenFixpoint",
            Pp.str "the recursive argument needs to be specified");
     in
     let check_exists_args an =
       try 
	 let id = match an with Struct id -> id | Wf(_,Some id) -> id | Mes(_,Some id) -> id | Wf(_,None) | Mes(_,None) -> failwith "check_exists_args" in 
	 (try ignore(Util.list_index (Name id) names - 1); annot
	  with Not_found ->  Util.user_err_loc
            (Util.dummy_loc,"GenFixpoint",
             Pp.str "No argument named " ++ Nameops.pr_id id)
	 )
       with Failure "check_exists_args" ->  check_one_name ();annot
     in
     let ni =
       match annot with
         | None ->
             annot
	 | Some an ->
	     check_exists_args an
     in
     (id, ni, bl, type_, def) ]
      END


VERNAC ARGUMENT EXTEND rec_definitions2
| [ rec_definition2(rd) ] -> [ [rd] ]
| [ rec_definition2(hd) "with" rec_definitions2(tl) ] -> [ hd::tl ]
END


VERNAC COMMAND EXTEND GenFixpoint
   ["GenFixpoint" rec_definitions2(recsl)] ->
	[ do_generate_principle false  recsl]
END

VERNAC COMMAND EXTEND IGenFixpoint
   ["IGenFixpoint" rec_definitions2(recsl)] ->
	[ do_generate_principle true  recsl]
END


VERNAC ARGUMENT EXTEND fun_scheme_arg
| [ ident(princ_name) ":=" "Induction" "for" ident(fun_name) "Sort" sort(s) ] -> [ (princ_name,fun_name,s) ] 
END 

VERNAC ARGUMENT EXTEND fun_scheme_args
| [ fun_scheme_arg(fa) ] -> [ [fa] ] 
| [ fun_scheme_arg(fa) "with" fun_scheme_args(fas) ] -> [fa::fas]
END 

VERNAC COMMAND EXTEND NewFunctionalScheme
   ["New" "Functional" "Scheme" fun_scheme_args(fas) ] ->
    [
      New_arg_principle.make_scheme fas
    ]
END


VERNAC COMMAND EXTEND NewFunctionalCase
   ["New" "Functional" "Case" fun_scheme_arg(fas) ] ->
    [
      New_arg_principle.make_case_scheme fas
    ]
END


VERNAC COMMAND EXTEND GenerateGraph 
["Generate" "graph" "for" ident(c)] -> [ make_graph c ]
END