(************************************************************************)
(*  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        *)
(************************************************************************)

(* $Id: g_ltac.ml4,v 1.28.2.2 2004/07/16 19:30:38 herbelin Exp $ *)

open Pp
open Util
open Ast
open Topconstr
open Rawterm
open Tacexpr
open Vernacexpr
open Ast
open Pcoq
open Prim
open Tactic

type let_clause_kind =
  | LETTOPCLAUSE of Names.identifier * constr_expr
  | LETCLAUSE of
      (Names.identifier Util.located * raw_tactic_expr option * raw_tactic_arg)

let fail_default_value = Genarg.ArgArg 0

let out_letin_clause loc = function
  | LETTOPCLAUSE _ -> user_err_loc (loc, "", (str "Syntax Error"))
  | LETCLAUSE (id,c,d) -> (id,c,d)

let make_letin_clause loc = List.map (out_letin_clause loc)

let arg_of_expr = function
    TacArg a -> a
  | e -> Tacexp (e:raw_tactic_expr)
    
(* Tactics grammar rules *)

if !Options.v7 then
GEXTEND Gram
  GLOBAL: tactic Vernac_.command tactic_arg;

(*
  GLOBAL: tactic_atom tactic_atom0 tactic_expr input_fun;
*)
  input_fun:
    [ [ l = base_ident -> Some l
      | "()" -> None ] ]
  ;
  let_clause:
    [ [ id = identref; "="; te = tactic_letarg -> LETCLAUSE (id, None, te)
      | id = base_ident; ":"; c = Constr.constr; ":="; "Proof" ->
          LETTOPCLAUSE (id, c)
      | id = identref; ":"; c = constrarg; ":="; te = tactic_letarg ->
          LETCLAUSE (id, Some (TacArg(ConstrMayEval c)), te)
      |	id = base_ident; ":"; c = Constr.constr ->
	  LETTOPCLAUSE (id, c) ] ]
  ;
  rec_clause:
    [ [ name = identref; it = LIST1 input_fun; "->"; body = tactic_expr ->
          (name,(it,body)) ] ]
  ;
  match_pattern:
    [ [ id = Constr.constr_pattern; "["; pc = Constr.constr_pattern; "]" ->
        let (_,s) = coerce_to_id id in Subterm (Some s, pc)
      | "["; pc = Constr.constr_pattern; "]" -> Subterm (None,pc)
      | pc = Constr.constr_pattern -> Term pc ] ]
  ;
  match_hyps:
    [ [ na = name; ":"; mp =  match_pattern -> Hyp (na, mp) ] ]
  ;
  match_context_rule:
    [ [ "["; largs = LIST0 match_hyps SEP ";"; "|-"; mp = match_pattern; "]";
        "->"; te = tactic_expr -> Pat (largs, mp, te)
      | IDENT "_"; "->"; te = tactic_expr -> All te ] ]
  ;
  match_context_list:
    [ [ mrl = LIST1 match_context_rule SEP "|" -> mrl
      | "|"; mrl = LIST1 match_context_rule SEP "|" -> mrl ] ]
  ;
  match_rule:
    [ [ "["; mp = match_pattern; "]"; "->"; te = tactic_expr -> Pat ([],mp,te)
      | IDENT "_"; "->"; te = tactic_expr -> All te ] ]
  ;
  match_list:
    [ [ mrl = LIST1 match_rule SEP "|" -> mrl
      | "|"; mrl = LIST1 match_rule SEP "|" -> mrl ] ]
  ;
  tactic_expr:
    [ [ ta = tactic_expr5 -> ta ] ]
  ;
  tactic_expr5:
    [ [ ta0 = tactic_expr5; ";"; ta1 = tactic_expr4 -> TacThen (ta0, ta1)
      | ta = tactic_expr5; ";"; "["; lta = LIST0 tactic_expr SEP "|"; "]" ->
          TacThens (ta, lta)
      | y = tactic_expr4 -> y ] ]
  ;
  tactic_expr4:
    [ [ ta = tactic_expr3 -> ta ] ]
  ;
  tactic_expr3:
    [ [ IDENT "Try"; ta = tactic_expr3 -> TacTry ta
      | IDENT "Do"; n = int_or_var; ta = tactic_expr3 -> TacDo (n,ta)
      | IDENT "Repeat"; ta = tactic_expr3 -> TacRepeat ta
      | IDENT "Progress"; ta = tactic_expr3 -> TacProgress ta
      | IDENT "Info"; tc = tactic_expr3 -> TacInfo tc
      | ta = tactic_expr2 -> ta ] ]
  ;
  tactic_expr2:
    [ [ ta0 = tactic_atom; "Orelse"; ta1 = tactic_expr3 -> TacOrelse (ta0,ta1)
      | ta = tactic_atom -> ta ] ]
  ;
  tactic_atom:
    [ [ IDENT "Fun"; it = LIST1 input_fun ; "->"; body = tactic_expr ->
          TacFun (it,body)
      | IDENT "Rec"; rc = rec_clause ->
	  warning "'Rec f ...' is obsolete; use 'Rec f ... In f' instead";
	  TacLetRecIn ([rc],TacArg (Reference (Libnames.Ident (fst rc))))
      | IDENT "Rec"; rc = rec_clause; rcl = LIST0 rec_clause SEP "And";
	  [IDENT "In" | "in"]; body = tactic_expr -> TacLetRecIn (rc::rcl,body)
      | IDENT "Let"; llc = LIST1 let_clause SEP "And"; IDENT "In";
          u = tactic_expr -> TacLetIn (make_letin_clause loc llc,u)

      | IDENT "Match"; IDENT "Context"; IDENT "With"; mrl = match_context_list
        -> TacMatchContext (false,mrl)
      | IDENT "Match"; IDENT "Reverse"; IDENT "Context"; IDENT "With"; mrl = match_context_list
        -> TacMatchContext (true,mrl)
      |	IDENT "Match"; c = constrarg; IDENT "With"; mrl = match_list ->
        TacMatch (TacArg(ConstrMayEval c),mrl)
(*To do: put Abstract in Refiner*)
      | IDENT "Abstract"; tc = tactic_expr -> TacAbstract (tc,None)
      | IDENT "Abstract"; tc = tactic_expr; "using";  s = base_ident ->
          TacAbstract (tc,Some s)
(*End of To do*)
      | IDENT "First" ; "["; l = LIST0 tactic_expr SEP "|"; "]" ->
	  TacFirst l
      | IDENT "Solve" ; "["; l = LIST0 tactic_expr SEP "|"; "]" ->
	  TacSolve l
      | IDENT "Idtac" ; s = [ s = STRING -> s | -> ""] -> TacId s
      | IDENT "Fail"; n = [ n = int_or_var -> n | -> fail_default_value ];
	  s = [ s = STRING -> s | -> ""] -> TacFail (n,s)
      | st = simple_tactic -> TacAtom (loc,st)
      | "("; a = tactic_expr; ")" -> a
      | a = tactic_arg -> TacArg a
    ] ]
  ;
  (* Tactic arguments *)
  tactic_arg:
    [ [ ta = tactic_arg1 -> ta ] ]
  ;
  tactic_letarg:
    (* Cannot be merged with tactic_arg1, since then "In"/"And" are 
       parsed as lqualid! *)
    [ [ IDENT "Eval"; rtc = red_expr; "in"; c = Constr.constr ->
	  ConstrMayEval (ConstrEval (rtc,c))
      | IDENT "Inst"; id = identref; "["; c = Constr.constr; "]" ->
	  ConstrMayEval (ConstrContext (id,c))
      | IDENT "Check"; c = Constr.constr ->
	  ConstrMayEval (ConstrTypeOf c)
      | IDENT "FreshId"; s = OPT STRING -> TacFreshId s
      | IDENT "ipattern"; ":"; ipat = simple_intropattern -> IntroPattern ipat
      | r = reference -> Reference r
      | ta = tactic_arg0 -> ta ] ]
  ;
  tactic_arg1:
    [ [ IDENT "Eval"; rtc = red_expr; "in"; c = Constr.constr ->
	  ConstrMayEval (ConstrEval (rtc,c))
      | IDENT "Inst"; id = identref; "["; c = Constr.constr; "]" ->
	  ConstrMayEval (ConstrContext (id,c))
      | IDENT "Check"; c = Constr.constr ->
	  ConstrMayEval (ConstrTypeOf c)
      | IDENT "FreshId"; s = OPT STRING -> TacFreshId s
      | IDENT "ipattern"; ":"; ipat = simple_intropattern -> IntroPattern ipat
      | r = reference; la = LIST1 tactic_arg0 -> TacCall (loc,r,la)
      | r = reference -> Reference r
      | ta = tactic_arg0 -> ta ] ]
  ;
  tactic_arg0:
    [ [ "("; a = tactic_expr; ")" -> arg_of_expr a
      | "()" -> TacVoid
      | r = reference -> Reference r
      | n = integer -> Integer n
      | id = METAIDENT -> MetaIdArg (loc,id)
      |	"?" -> ConstrMayEval (ConstrTerm (CHole loc))
      | "?"; n = natural -> ConstrMayEval (ConstrTerm (CPatVar (loc,(false,Pattern.patvar_of_int n))))
      |	"'"; c = Constr.constr -> ConstrMayEval (ConstrTerm c) ] ]
  ;

  (* Definitions for tactics *)
  deftok:
    [ [ IDENT "Meta"
      | IDENT "Tactic" ] ]
  ;
  tacdef_body:
    [ [ name = identref; it=LIST1 input_fun; ":="; body = tactic_expr ->
	  (name, TacFun (it, body))
      | name = identref; ":="; body = tactic_expr ->
	  (name, body) ] ]
  ;
  tactic:
    [ [ tac = tactic_expr -> tac ] ]
  ;
  Vernac_.command: 
    [ [ deftok; "Definition"; b = tacdef_body ->
          VernacDeclareTacticDefinition (false, [b])
      | IDENT "Recursive"; deftok; "Definition"; 
        l = LIST1 tacdef_body SEP "And" ->
          VernacDeclareTacticDefinition (true, l) ] ]
  ;
  END