X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Focaml%2Fcic_disambiguation%2FcicTextualParser2.ml;h=d5f427c4f92f039367f722eceb4abf3bb0ce6b68;hb=7e9904185ceff75884783dbf0bad506b8521b857;hp=0ac8ab38072ec67a81e5567412ebafc5604d2180;hpb=d4a5f73930368705b8ce07c11ecff94e04465acb;p=helm.git

diff --git a/helm/ocaml/cic_disambiguation/cicTextualParser2.ml b/helm/ocaml/cic_disambiguation/cicTextualParser2.ml
index 0ac8ab380..d5f427c4f 100644
--- a/helm/ocaml/cic_disambiguation/cicTextualParser2.ml
+++ b/helm/ocaml/cic_disambiguation/cicTextualParser2.ml
@@ -23,7 +23,7 @@
  * http://helm.cs.unibo.it/
  *)
 
-let debug = true
+let debug = false
 let debug_print s =
   if debug then begin
     prerr_endline "<NEW_TEXTUAL_PARSER>";
@@ -31,99 +31,249 @@ let debug_print s =
     prerr_endline "</NEW_TEXTUAL_PARSER>"
   end
 
+  (** if set to true each number will have a different insance number and can
+  * thus be interpreted differently than others *)
+let use_fresh_num_instances = false
+
+  (** does the lexer return COMMENT tokens? *)
+let return_comments = false
+
 open Printf
 
-exception Parse_error of string
+open DisambiguateTypes
+
+exception Parse_error of Token.flocation * string
+
+let cic_lexer = CicTextualLexer2.cic_lexer ~comments:return_comments ()
+
+let fresh_num_instance =
+  let n = ref 0 in
+  if use_fresh_num_instances then
+    (fun () -> incr n; !n)
+  else
+    (fun () -> 0)
 
-let grammar = Grammar.gcreate CicTextualLexer2.lex
+let choice_of_uri uri =
+  let term = CicUtil.term_of_uri uri in
+  (uri, (fun _ _ _ -> term))
+
+let grammar = Grammar.gcreate cic_lexer
 
 let term = Grammar.Entry.create grammar "term"
-(* let tactic = Grammar.Entry.create grammar "tactic" *)
-(* let tactical = Grammar.Entry.create grammar "tactical" *)
+let term0 = Grammar.Entry.create grammar "term0"
+let tactic = Grammar.Entry.create grammar "tactic"
+let tactical = Grammar.Entry.create grammar "tactical"
+let tactical0 = Grammar.Entry.create grammar "tactical0"
+let command = Grammar.Entry.create grammar "command"
+let script = Grammar.Entry.create grammar "script"
 
-let return_term loc term = CicTextualParser2Ast.LocatedTerm (loc, term)
-(* let return_term loc term = term *)
+let return_term loc term = CicAst.AttributedTerm (`Loc loc, term)
+let return_tactic loc tactic = TacticAst.LocatedTactic (loc, tactic)
+let return_tactical loc tactical = TacticAst.LocatedTactical (loc, tactical)
+let return_command loc cmd = cmd  (* TODO ZACK FIXME uhm ... why we drop loc? *)
 
-let fail (x, y) msg =
+let fail floc msg =
+  let (x, y) = CicAst.loc_of_floc floc in
   failwith (Printf.sprintf "Error at characters %d - %d: %s" x y msg)
 
+let name_of_string = function
+  | "_" -> Cic.Anonymous
+  | s -> Cic.Name s
+
+let string_of_name = function
+  | Cic.Anonymous -> "_"
+  | Cic.Name s -> s
+  
+let int_opt = function
+  | None -> None
+  | Some lexeme -> Some (int_of_string lexeme)
+
+  (** the uri of an inductive type (a ".ind" uri) is not meaningful without an
+  * xpointer. Still, it's likely that an user who wrote "cic:/blabla/foo.ind"
+  * actually meant "cic:/blabla/foo.ind#xpointer(1/1)", i.e. the first inductive
+  * type in a block of mutual inductive types.
+  *
+  * This function performs the expansion foo.ind -> foo#xpointer..., if needed
+  *)
+let ind_expansion uri =
+  let len = String.length uri in
+  if len >= 4 && String.sub uri (len - 4) 4 = ".ind" then
+    uri ^ "#xpointer(1/1)"
+  else
+    uri
+
 EXTEND
-  GLOBAL: term;
+  GLOBAL: term term0 tactic tactical tactical0 command script;
+  int: [
+    [ num = NUM ->
+        try
+          int_of_string num
+        with Failure _ -> raise (Parse_error (loc, "integer literal expected"))
+    ]
+  ];
   meta_subst: [
     [ s = SYMBOL "_" -> None
     | t = term -> Some t ]
   ];
   binder: [
     [ SYMBOL <:unicode<lambda>> (* λ *) -> `Lambda
-    | SYMBOL <:unicode<pi>> (* π *) -> `Pi
+    | SYMBOL <:unicode<Pi>>     (* Π *) -> `Pi
     | SYMBOL <:unicode<exists>> (* ∃ *) -> `Exists
-    | SYMBOL <:unicode<forall>> (* ∀ *) -> `Forall
+    | SYMBOL <:unicode<forall>> (* ∀ *) -> `Forall ]
+  ];
+  sort: [
+    [ "Prop" -> `Prop
+    | "Set" -> `Set
+    | "Type" -> `Type
+    | "CProp" -> `CProp ]
+  ];
+  typed_name: [
+    [ PAREN "("; i = IDENT; SYMBOL ":"; typ = term; PAREN ")" ->
+        (Cic.Name i, Some typ)
+    | i = IDENT -> (Cic.Name i, None)
     ]
   ];
-  substituted_name: [ (* a subs.name is an explicit substitution subject *)
-    [ s = [ IDENT | SYMBOL ];
-      subst = OPT [
-        SYMBOL "\subst";  (* to avoid catching frequent "a [1]" cases *)
-        LPAREN "[";
+  subst: [
+    [ subst = OPT [
+        SYMBOL "\\subst";  (* to avoid catching frequent "a [1]" cases *)
+        PAREN "[";
         substs = LIST1 [
           i = IDENT; SYMBOL <:unicode<Assign>> (* ≔ *); t = term -> (i, t)
         ] SEP SYMBOL ";";
-        RPAREN "]" ->
+        PAREN "]" ->
           substs
-      ] ->
-        (match subst with
-        | Some l -> CicTextualParser2Ast.Ident (s, l)
-        | None -> CicTextualParser2Ast.Ident (s, []))
+      ] -> subst
+    ]
+  ];
+  substituted_name: [ (* a subs.name is an explicit substitution subject *)
+    [ s = IDENT; subst = subst -> CicAst.Ident (s, subst)
+    | s = URI; subst = subst -> CicAst.Uri (ind_expansion s, subst)
     ]
   ];
   name: [ (* as substituted_name with no explicit substitution *)
     [ s = [ IDENT | SYMBOL ] -> s ]
   ];
   pattern: [
-    [ n = name -> [n]
-    | LPAREN "("; names = LIST1 name; RPAREN ")" -> names ]
+    [ n = name -> (n, [])
+    | PAREN "("; head = name; vars = LIST1 typed_name; PAREN ")" ->
+        (head, vars)
+    ]
   ];
+  let_defs:[
+    [ defs = LIST1 [
+        name = IDENT;
+        args = LIST1 [
+          PAREN "(" ; names = LIST1 IDENT SEP SYMBOL ","; SYMBOL ":";
+          ty = term; PAREN ")" ->
+            (names, ty)
+        ];
+        index_name = OPT [ IDENT "on"; idx = IDENT -> idx ];
+        ty = OPT [ SYMBOL ":" ; t = term -> t ];
+        SYMBOL <:unicode<def>> (* ≝ *);
+        t1 = term ->
+          let rec list_of_binder binder ty final_term = function
+            | [] -> final_term
+            | name::tl -> 
+                CicAst.Binder (binder, (Cic.Name name, Some ty), 
+                  list_of_binder binder ty final_term tl)
+          in
+          let rec binder_of_arg_list binder final_term = function
+            | [] -> final_term
+            | (l,ty)::tl ->  
+                list_of_binder binder ty 
+                  (binder_of_arg_list binder final_term tl) l
+          in
+          let t1' = binder_of_arg_list `Lambda t1 args in
+          let ty' = 
+            match ty with 
+            | None -> None
+            | Some ty -> Some (binder_of_arg_list `Pi ty args)
+          in
+          let rec get_position_of name n = function 
+            | [] -> (None,n)
+            | nam::tl -> 
+                if nam = name then 
+                  (Some n,n) 
+                else 
+                  (get_position_of name (n+1) tl)
+          in
+          let rec find_arg name n = function 
+            | [] -> (fail loc (sprintf "Argument %s not found" name))
+            | (l,_)::tl -> 
+                let (got,len) = get_position_of name 0 l in
+                (match got with 
+                | None -> (find_arg name (n+len) tl)
+                | Some where -> n + where)
+          in
+          let index = 
+            (match index_name with 
+             | None -> 0 
+             | (Some name) -> find_arg name 0 args)
+          in
+          ((Cic.Name name,ty'), t1', index)
+      ] SEP "and" -> defs
+    ]];
+  constructor: [ [ name = IDENT; SYMBOL ":"; typ = term -> (name, typ) ] ];
+  term0: [ [ t = term; EOI -> return_term loc t ] ];
   term:
-    [ "arrow" RIGHTA
-      [ t1 = term; SYMBOL <:unicode<to>>; t2 = term ->
-          return_term loc
-            (CicTextualParser2Ast.Binder (`Pi, Cic.Anonymous, Some t1, t2))
-      ]
-    | "eq" LEFTA
-      [ t1 = term; SYMBOL "="; t2 = term ->
-        return_term loc (CicTextualParser2Ast.Appl_symbol ("eq", 0, [t1; t2]))
+    [ "letin" NONA
+      [ "let"; var = typed_name;
+        SYMBOL <:unicode<def>> (* ≝ *);
+        t1 = term; "in"; t2 = term ->
+          return_term loc (CicAst.LetIn (var, t1, t2))
+      | "let"; ind_kind = [ "corec" -> `CoInductive | "rec"-> `Inductive ];
+        defs = let_defs; "in"; body = term ->
+            return_term loc (CicAst.LetRec (ind_kind, defs, body))
       ]
-    | "add" LEFTA     [ (* nothing here by default *) ]
-    | "mult" LEFTA    [ (* nothing here by default *) ]
-    | "inv" NONA      [ (* nothing here by default *) ]
-    | "simple" NONA
+    | "binder" RIGHTA
       [
-        b = binder; vars = LIST1 IDENT SEP SYMBOL ",";
-        typ = OPT [ SYMBOL ":"; t = term -> t ];
+        b = binder;
+        (vars, typ) =
+          [ vars = LIST1 IDENT SEP SYMBOL ",";
+            typ = OPT [ SYMBOL ":"; t = term -> t ] -> (vars, typ)
+          | PAREN "("; vars = LIST1 IDENT SEP SYMBOL ",";
+            typ = OPT [ SYMBOL ":"; t = term -> t ]; PAREN ")" -> (vars, typ)
+          ];
         SYMBOL "."; body = term ->
           let binder =
             List.fold_right
               (fun var body ->
-                let name =
-                  match var with
-                  | "_" -> Cic.Anonymous
-                  | var -> Cic.Name var
-                in
-                CicTextualParser2Ast.Binder (b, name, typ, body))
+                let name = name_of_string var in
+                CicAst.Binder (b, (name, typ), body))
               vars body
           in
           return_term loc binder
-      | sort_kind = [
-          "Prop" -> `Prop | "Set" -> `Set | "Type" -> `Type | "CProp" -> `CProp
-        ] ->
-          CicTextualParser2Ast.Sort sort_kind
+      | t1 = term; SYMBOL <:unicode<to>> (* → *); t2 = term ->
+            return_term loc
+              (CicAst.Binder (`Pi, (Cic.Anonymous, Some t1), t2))
+      ]
+    | "logic_add" LEFTA   [ (* nothing here by default *) ]
+    | "logic_mult" LEFTA  [ (* nothing here by default *) ]
+    | "logic_inv" NONA    [ (* nothing here by default *) ]
+    | "relop" LEFTA
+      [ t1 = term; SYMBOL "="; t2 = term ->
+        return_term loc (CicAst.Appl [CicAst.Symbol ("eq", 0); t1; t2])
+      ]
+    | "add" LEFTA     [ (* nothing here by default *) ]
+    | "mult" LEFTA    [ (* nothing here by default *) ]
+    | "power" LEFTA   [ (* nothing here by default *) ]
+    | "inv" NONA      [ (* nothing here by default *) ]
+    | "apply" LEFTA
+      [ t1 = term; t2 = term ->
+        let rec aux = function
+          | CicAst.Appl (hd :: tl) -> aux hd @ tl
+          | term -> [term]
+        in
+        CicAst.Appl (aux t1 @ [t2])
+      ]
+    | "simple" NONA
+      [ sort = sort -> CicAst.Sort sort
       | n = substituted_name -> return_term loc n
-      | LPAREN "("; head = term; args = LIST1 term; RPAREN ")" ->
-          return_term loc (CicTextualParser2Ast.Appl (head :: args))
-      | i = NUM -> return_term loc (CicTextualParser2Ast.Num (i, 0))
+      | i = NUM -> return_term loc (CicAst.Num (i, (fresh_num_instance ())))
+      | IMPLICIT -> return_term loc CicAst.Implicit
       | m = META;
         substs = [
-          LPAREN "["; substs = LIST0 meta_subst SEP SYMBOL ";" ; RPAREN "]" ->
+          PAREN "["; substs = LIST0 meta_subst SEP SYMBOL ";" ; PAREN "]" ->
             substs
         ] ->
             let index =
@@ -132,43 +282,346 @@ EXTEND
               with Failure "int_of_string" ->
                 fail loc ("Invalid meta variable number: " ^ m)
             in
-            return_term loc (CicTextualParser2Ast.Meta (index, substs))
-        (* actually "in" and "and" are _not_ keywords. Parsing works anyway
-         * since applications are required to be bound by parens *)
-      | "let"; name = IDENT; SYMBOL <:unicode<def>> (* ≝ *); t1 = term;
-        IDENT "in"; t2 = term ->
-          return_term loc (CicTextualParser2Ast.LetIn (name, t1, t2))
-      | "let"; ind_kind = [ "corec" -> `CoInductive | "rec"-> `Inductive ];
-          defs = LIST1 [
-          name = IDENT;
-          index = OPT [ LPAREN "("; index = INT; RPAREN ")" ->
-            int_of_string index
-          ];
-          typ = OPT [ SYMBOL ":"; typ = term -> typ ];
-          SYMBOL <:unicode<def>> (* ≝ *); t1 = term ->
-            (name, t1, typ, (match index with None -> 1 | Some i -> i))
-        ] SEP (IDENT "and");
-        IDENT "in"; body = term ->
-          return_term loc (CicTextualParser2Ast.LetRec (ind_kind, defs, body))
-      | outtyp = OPT [ LPAREN "["; typ = term; RPAREN "]" -> typ ];
+            return_term loc (CicAst.Meta (index, substs))
+      | outtyp = OPT [ PAREN "["; typ = term; PAREN "]" -> typ ];
         "match"; t = term;
-        SYMBOL ":"; indty = IDENT;
+        indty_ident = OPT [ SYMBOL ":"; id = IDENT -> id ];
         "with";
-        LPAREN "[";
+        PAREN "[";
         patterns = LIST0 [
-          p = pattern; SYMBOL <:unicode<Rightarrow>> (* ⇒ *); t = term -> (p, t)
+          lhs = pattern; SYMBOL <:unicode<Rightarrow>> (* ⇒ *); rhs = term
+          ->
+            ((lhs: CicAst.case_pattern), rhs)
         ] SEP SYMBOL "|";
-        RPAREN "]" ->
-          return_term loc (CicTextualParser2Ast.Case (t, indty, outtyp, patterns))
-      | LPAREN "("; t = term; RPAREN ")" -> return_term loc t
+        PAREN "]" ->
+          return_term loc
+            (CicAst.Case (t, indty_ident, outtyp, patterns))
+      | PAREN "("; t1 = term; SYMBOL ":"; t2 = term; PAREN ")" ->
+          return_term loc (CicAst.Appl [CicAst.Symbol ("cast", 0); t1; t2])
+      | PAREN "("; t = term; PAREN ")" -> return_term loc t
+      ]
+    ];
+  tactic_where: [
+    [ where = OPT [ "in"; ident = IDENT -> ident ] -> where ]
+  ];
+  tactic_term: [ [ t = term -> t ] ];
+  ident_list0: [
+    [ PAREN "["; idents = LIST0 IDENT SEP SYMBOL ";"; PAREN "]" -> idents ]
+  ];
+  ident_list1: [
+    [ PAREN "["; idents = LIST1 IDENT SEP SYMBOL ";"; PAREN "]" -> idents ]
+  ];
+  reduction_kind: [
+    [ [ IDENT "reduce" | IDENT "Reduce" ] -> `Reduce
+    | [ IDENT "simplify" | IDENT "Simplify" ] -> `Simpl
+    | [ IDENT "whd" | IDENT "Whd" ] -> `Whd ]
+  ];
+  tactic: [
+    [ [ IDENT "absurd" | IDENT "Absurd" ]; t = tactic_term ->
+        return_tactic loc (TacticAst.Absurd t)
+    | [ IDENT "apply" | IDENT "Apply" ]; t = tactic_term ->
+        return_tactic loc (TacticAst.Apply t)
+    | [ IDENT "assumption" | IDENT "Assumption" ] ->
+        return_tactic loc TacticAst.Assumption
+    | [ IDENT "auto" | IDENT "Auto" ] -> return_tactic loc TacticAst.Auto
+    | [ IDENT "change" | IDENT "Change" ];
+      t1 = tactic_term; "with"; t2 = tactic_term;
+      where = tactic_where ->
+        return_tactic loc (TacticAst.Change (t1, t2, where))
+    (* TODO Change_pattern *)
+    | [ IDENT "contradiction" | IDENT "Contradiction" ] ->
+        return_tactic loc TacticAst.Contradiction
+    | [ IDENT "cut" | IDENT "Cut" ];
+      t = tactic_term -> return_tactic loc (TacticAst.Cut t)
+    | [ IDENT "decompose" | IDENT "Decompose" ];
+      principles = ident_list1; where = IDENT ->
+        return_tactic loc (TacticAst.Decompose (where, principles))
+    | [ IDENT "discriminate" | IDENT "Discriminate" ];
+      hyp = IDENT ->
+        return_tactic loc (TacticAst.Discriminate hyp)
+    | [ IDENT "elimType" | IDENT "ElimType" ]; t = tactic_term ->
+        return_tactic loc (TacticAst.ElimType t)
+    | [ IDENT "elim" | IDENT "Elim" ];
+      t1 = tactic_term;
+      using = OPT [ "using"; using = tactic_term -> using ] ->
+        return_tactic loc (TacticAst.Elim (t1, using))
+    | [ IDENT "exact" | IDENT "Exact" ]; t = tactic_term ->
+        return_tactic loc (TacticAst.Exact t)
+    | [ IDENT "exists" | IDENT "Exists" ] ->
+        return_tactic loc TacticAst.Exists
+    | [ IDENT "fold" | IDENT "Fold" ];
+      kind = reduction_kind; t = tactic_term ->
+        return_tactic loc (TacticAst.Fold (kind, t))
+    | [ IDENT "fourier" | IDENT "Fourier" ] ->
+        return_tactic loc TacticAst.Fourier
+    | [ IDENT "hint" | IDENT "Hint" ] -> return_tactic loc TacticAst.Hint
+    | [ IDENT "injection" | IDENT "Injection" ]; ident = IDENT ->
+        return_tactic loc (TacticAst.Injection ident)
+    | [ IDENT "intros" | IDENT "Intros" ];
+      num = OPT [ num = int -> num ];
+      idents = OPT ident_list0 ->
+        let idents = match idents with None -> [] | Some idents -> idents in
+        return_tactic loc (TacticAst.Intros (num, idents))
+    | [ IDENT "intro" | IDENT "Intro" ] ->
+        return_tactic loc (TacticAst.Intros (None, []))
+    | [ IDENT "left" | IDENT "Left" ] -> return_tactic loc TacticAst.Left
+    | [ "let" | "Let" ];
+      t = tactic_term; "in"; where = IDENT ->
+        return_tactic loc (TacticAst.LetIn (t, where))
+    | kind = reduction_kind;
+      pat = OPT [
+        "in"; pat = [ IDENT "goal" -> `Goal | IDENT "hyp" -> `Everywhere ] ->
+          pat
+      ];
+      terms = LIST0 term SEP SYMBOL "," ->
+        let tac =
+          (match (pat, terms) with
+          | None, [] -> TacticAst.Reduce (kind, None)
+          | None, terms -> TacticAst.Reduce (kind, Some (terms, `Goal))
+          | Some pat, [] -> TacticAst.Reduce (kind, Some ([], pat))
+          | Some pat, terms -> TacticAst.Reduce (kind, Some (terms, pat)))
+        in
+        return_tactic loc tac
+    | [ IDENT "reflexivity" | IDENT "Reflexivity" ] ->
+        return_tactic loc TacticAst.Reflexivity
+    | [ IDENT "replace" | IDENT "Replace" ];
+      t1 = tactic_term; "with"; t2 = tactic_term ->
+        return_tactic loc (TacticAst.Replace (t1, t2))
+    (* TODO Rewrite *)
+    (* TODO Replace_pattern *)
+    | [ IDENT "right" | IDENT "Right" ] -> return_tactic loc TacticAst.Right
+    | [ IDENT "ring" | IDENT "Ring" ] -> return_tactic loc TacticAst.Ring
+    | [ IDENT "split" | IDENT "Split" ] -> return_tactic loc TacticAst.Split
+    | [ IDENT "symmetry" | IDENT "Symmetry" ] ->
+        return_tactic loc TacticAst.Symmetry
+    | [ IDENT "transitivity" | IDENT "Transitivity" ];
+      t = tactic_term ->
+        return_tactic loc (TacticAst.Transitivity t)
+    ]
+  ];
+  tactical0: [ [ t = tactical; SYMBOL "." -> return_tactical loc t ] ];
+  tactical:
+    [ "command" NONA
+      [ cmd = command -> return_tactical loc (TacticAst.Command cmd) ]
+    | "sequence" LEFTA
+      [ tactics = LIST1 NEXT SEP SYMBOL ";" ->
+          (match tactics with
+          | [tactic] -> tactic
+          | _ -> return_tactical loc (TacticAst.Seq tactics))
+      ]
+    | "then" NONA
+      [ tac = tactical;
+        PAREN "["; tacs = LIST0 tactical SEP SYMBOL ";"; PAREN "]" ->
+          return_tactical loc (TacticAst.Then (tac, tacs))
+      ]
+    | "loops" RIGHTA
+      [ [ IDENT "do" | IDENT "Do" ]; count = int; tac = tactical ->
+          return_tactical loc (TacticAst.Do (count, tac))
+      | [ IDENT "repeat" | IDENT "Repeat" ]; tac = tactical ->
+          return_tactical loc (TacticAst.Repeat tac)
+      ]
+    | "simple" NONA
+      [ [ IDENT "tries" | IDENT "Tries" ];
+        PAREN "["; tacs = LIST0 tactical SEP SYMBOL ";"; PAREN "]" ->
+          return_tactical loc (TacticAst.Tries tacs)
+      | [ IDENT "try" | IDENT "Try" ]; tac = NEXT ->
+          return_tactical loc (TacticAst.Try tac)
+      | [ IDENT "fail" | IDENT "Fail" ] -> return_tactical loc TacticAst.Fail
+      | [ IDENT "id" | IDENT "Id" ] -> return_tactical loc TacticAst.IdTac
+      | PAREN "("; tac = tactical; PAREN ")" -> return_tactical loc tac
+      | tac = tactic -> return_tactical loc (TacticAst.Tactic tac)
       ]
     ];
+  theorem_flavour: [  (* all flavours but Goal *)
+    [ [ IDENT "definition"  | IDENT "Definition"  ] -> `Definition
+    | [ IDENT "fact"        | IDENT "Fact"        ] -> `Fact
+    | [ IDENT "lemma"       | IDENT "Lemma"       ] -> `Lemma
+    | [ IDENT "remark"      | IDENT "Remark"      ] -> `Remark
+    | [ IDENT "theorem"     | IDENT "Theorem"     ] -> `Theorem
+    ]
+  ];
+  inductive_spec: [ [
+    fst_name = IDENT; params = LIST0 [
+      PAREN "("; names = LIST1 IDENT SEP SYMBOL ","; SYMBOL ":";
+      typ = term; PAREN ")" -> (names, typ) ];
+    SYMBOL ":"; fst_typ = term; SYMBOL <:unicode<def>>; OPT SYMBOL "|";
+    fst_constructors = LIST0 constructor SEP SYMBOL "|";
+    tl = OPT [ "with";
+      types = LIST1 [
+        name = IDENT; SYMBOL ":"; typ = term; SYMBOL <:unicode<def>>;
+       OPT SYMBOL "|"; constructors = LIST0 constructor SEP SYMBOL "|" ->
+          (name, true, typ, constructors) ] SEP "with" -> types
+    ] ->
+      let params =
+        List.fold_right
+          (fun (names, typ) acc ->
+            (List.map (fun name -> (name, typ)) names) @ acc)
+          params []
+      in
+      let fst_ind_type = (fst_name, true, fst_typ, fst_constructors) in
+      let tl_ind_types = match tl with None -> [] | Some types -> types in
+      let ind_types = fst_ind_type :: tl_ind_types in
+      (params, ind_types)
+  ] ];
+  print_kind: [
+    [ [ IDENT "Env" | IDENT "env" | IDENT "Environment" | IDENT "environment" ]
+      -> `Env
+    | [ IDENT "Coer" | IDENT "coer" | IDENT "Coercions" | IDENT "coercions" ]
+      -> `Coer
+  ] ];
+
+  command: [
+    [ [ IDENT "abort" | IDENT "Abort" ] -> return_command loc TacticAst.Abort
+    | [ IDENT "proof" | IDENT "Proof" ] -> return_command loc TacticAst.Proof
+    | [ IDENT "quit"  | IDENT "Quit"  ] -> return_command loc TacticAst.Quit
+    | [ IDENT "qed"   | IDENT "Qed"   ] ->
+        return_command loc (TacticAst.Qed None)
+    | [ IDENT "print"   | IDENT "Print" ];
+      print_kind = print_kind ->
+            return_command loc (TacticAst.Print print_kind)
+    | [ IDENT "save"  | IDENT "Save"  ]; name = IDENT ->
+        return_command loc (TacticAst.Qed (Some name))
+    | flavour = theorem_flavour; name = OPT IDENT; SYMBOL ":"; typ = term;
+      body = OPT [ SYMBOL <:unicode<def>> (* ≝ *); body = term -> body ] ->
+        return_command loc (TacticAst.Theorem (flavour, name, typ, body))
+    | "let"; ind_kind = [ "corec" -> `CoInductive | "rec"-> `Inductive ];
+        defs = let_defs -> 
+          let name,ty = 
+            match defs with
+            | ((Cic.Name name,Some ty),_,_) :: _ -> name,ty
+            | ((Cic.Name name,None),_,_) :: _ -> 
+                fail loc ("No type given for " ^ name)
+            | _ -> assert false 
+          in
+          let body = CicAst.Ident (name,None) in
+          TacticAst.Theorem(`Definition, Some name, ty,
+            Some (CicAst.LetRec (ind_kind, defs, body)))
+          
+    | [ IDENT "inductive" | IDENT "Inductive" ]; spec = inductive_spec ->
+        let (params, ind_types) = spec in
+        return_command loc (TacticAst.Inductive (params, ind_types))
+    | [ IDENT "coinductive" | IDENT "CoInductive" ]; spec = inductive_spec ->
+        let (params, ind_types) = spec in
+        let ind_types = (* set inductive flags to false (coinductive) *)
+          List.map (fun (name, _, term, ctors) -> (name, false, term, ctors))
+            ind_types
+        in
+        return_command loc (TacticAst.Inductive (params, ind_types))
+    | [ IDENT "coercion" | IDENT "Coercion" ] ; name = IDENT -> 
+        return_command loc (TacticAst.Coercion (CicAst.Ident (name,Some [])))
+    | [ IDENT "coercion" | IDENT "Coercion" ] ; name = URI -> 
+        return_command loc (TacticAst.Coercion (CicAst.Uri (name,Some [])))
+    | [ IDENT "goal" | IDENT "Goal" ]; typ = term;
+      body = OPT [ SYMBOL <:unicode<def>> (* ≝ *); body = term -> body ] ->
+        return_command loc (TacticAst.Theorem (`Goal, None, typ, body))
+    | [ IDENT "undo"   | IDENT "Undo" ]; steps = OPT NUM ->
+        return_command loc (TacticAst.Undo (int_opt steps))
+    | [ IDENT "redo"   | IDENT "Redo" ]; steps = OPT NUM ->
+        return_command loc (TacticAst.Redo (int_opt steps))
+    | [ IDENT "baseuri"   | IDENT "Baseuri" ]; uri = OPT QSTRING ->
+        return_command loc (TacticAst.Baseuri uri)
+    | [ IDENT "basedir"   | IDENT "Basedir" ]; uri = OPT QSTRING ->
+        return_command loc (TacticAst.Basedir uri)
+    | [ IDENT "check"   | IDENT "Check" ]; t = term ->
+        return_command loc (TacticAst.Check t)
+(*
+    | [ IDENT "alias"   | IDENT "Alias" ]; spec = alias_spec ->
+        return_command loc (TacticAst.Alias spec)
+*)
+    ]
+  ];
+  script_entry: [
+    [ cmd = tactical0 -> Command cmd
+(*     | s = COMMENT -> Comment (loc, s) *)
+    ]
+  ];
+  script: [ [ entries = LIST0 script_entry; EOI -> (loc, entries) ] ];
 END
 
-let parse_term stream =
+let exc_located_wrapper f =
   try
-    Grammar.Entry.parse term stream
-  with Stdpp.Exc_located ((x, y), exn) ->
-    raise (Parse_error (sprintf "parse error at characters %d-%d: %s" x y
-        (Printexc.to_string exn)))
+    f ()
+  with
+  | Stdpp.Exc_located (floc, Stream.Error msg) ->
+      raise (Parse_error (floc, msg))
+  | Stdpp.Exc_located (floc, exn) ->
+      raise (Parse_error (floc, (Printexc.to_string exn)))
+
+let parse_term stream =
+  exc_located_wrapper (fun () -> (Grammar.Entry.parse term0 stream))
+let parse_tactic stream =
+  exc_located_wrapper (fun () -> (Grammar.Entry.parse tactic stream))
+let parse_tactical stream =
+  exc_located_wrapper (fun () -> (Grammar.Entry.parse tactical0 stream))
+let parse_script stream =
+  exc_located_wrapper (fun () -> (Grammar.Entry.parse script stream))
+
+(**/**)
+
+(** {2 Interface for gTopLevel} *)
+
+module EnvironmentP3 =
+  struct
+    type t = environment
+
+    let empty = ""
+
+    let aliases_grammar = Grammar.gcreate cic_lexer
+    let aliases = Grammar.Entry.create aliases_grammar "aliases"
+
+    let to_string env =
+      let aliases =
+        Environment.fold
+          (fun domain_item (dsc, _) acc ->
+            let s =
+              match domain_item with
+              | Id id -> sprintf "alias id %s = %s" id dsc
+              | Symbol (symb, instance) ->
+                  sprintf "alias symbol \"%s\" (instance %d) = \"%s\""
+                    symb instance dsc
+              | Num instance ->
+                  sprintf "alias num (instance %d) = \"%s\"" instance dsc
+            in
+            s :: acc)
+          env []
+      in
+      String.concat "\n" (List.sort compare aliases)
+
+    EXTEND
+      GLOBAL: aliases;
+      aliases: [  (* build an environment from an aliases list *)
+        [ aliases = LIST0 alias; EOI ->
+            List.fold_left
+              (fun env (domain_item, codomain_item) ->
+                Environment.add domain_item codomain_item env)
+              Environment.empty aliases
+        ]
+      ];
+      alias: [  (* return a pair <domain_item, codomain_item> from an alias *)
+        [ IDENT "alias";
+          choice =
+            [ IDENT "id"; id = IDENT; SYMBOL "="; uri = URI ->
+                (Id id, choice_of_uri uri)
+            | IDENT "symbol"; symbol = QSTRING;
+              PAREN "("; IDENT "instance"; instance = NUM; PAREN ")";
+              SYMBOL "="; dsc = QSTRING ->
+                (Symbol (symbol, int_of_string instance),
+                 DisambiguateChoices.lookup_symbol_by_dsc symbol dsc)
+            | IDENT "num";
+              PAREN "("; IDENT "instance"; instance = NUM; PAREN ")";
+              SYMBOL "="; dsc = QSTRING ->
+                (Num (int_of_string instance),
+                 DisambiguateChoices.lookup_num_by_dsc dsc)
+            ] -> choice ]
+      ];
+    END
+
+    let of_string s =
+      if s = empty then
+        Environment.empty
+      else
+        exc_located_wrapper
+          (fun () -> Grammar.Entry.parse aliases (Stream.of_string s))
+  end
 
+(* vim:set encoding=utf8: *)