+(** {2 Grammar extension} *)
+
+type associativity_kind = [ `Left | `Right | `None ]
+
+let symbol s = Gramext.Stoken ("SYMBOL", s)
+let ident s = Gramext.Stoken ("IDENT", s)
+let number s = Gramext.Stoken ("NUMBER", s)
+let term = Gramext.Sself
+
+type env_type = (string * (value_type * value)) list
+
+let make_action action =
+ let rec aux (vl : env_type) =
+ prerr_endline "aux";
+ function
+ [] ->
+ prerr_endline "make_action";
+ Gramext.action (fun (loc : location) -> action vl loc)
+ | None :: tl -> Gramext.action (fun _ -> aux vl tl)
+ | Some (name, TermType) :: tl ->
+ Gramext.action
+ (fun (v : term) -> aux ((name, (TermType, TermValue v)) :: vl) tl)
+ | Some (name, StringType) :: tl ->
+ Gramext.action
+ (fun (v : string) ->
+ aux ((name, (StringType, StringValue v)) :: vl) tl)
+ | Some (name, NumType) :: tl ->
+ Gramext.action
+ (fun (v : string) -> aux ((name, (NumType, NumValue v)) :: vl) tl)
+ | Some (name, OptType t) :: tl ->
+ Gramext.action
+ (fun (v : 'a option) ->
+ aux ((name, (OptType t, OptValue v)) :: vl) tl)
+ | Some (name, ListType t) :: tl ->
+ Gramext.action
+ (fun (v : 'a list) ->
+ aux ((name, (ListType t, ListValue v)) :: vl) tl)
+ in
+ aux []
+
+let flatten_opt =
+ let rec aux acc =
+ function
+ [] -> List.rev acc
+ | None :: tl -> aux acc tl
+ | Some hd :: tl -> aux (hd :: acc) tl
+ in
+ aux []
+
+ (* given a level 1 pattern computes the new RHS of "term" grammar entry *)
+let extract_term_production pattern =
+ let rec aux =
+ function
+ Literal l -> aux_literal l
+ | Layout l -> aux_layout l
+ | Magic m -> aux_magic m
+ | Variable v -> aux_variable v
+ | _ -> assert false
+ and aux_literal =
+ function
+ `Symbol s -> [None, symbol s]
+ | `Keyword s -> [None, ident s]
+ | `Number s -> [None, number s]
+ and aux_layout =
+ function
+ Sub (p1, p2) -> aux p1 @ [None, symbol "\\SUB"] @ aux p2
+ | Sup (p1, p2) -> aux p1 @ [None, symbol "\\SUP"] @ aux p2
+ | Below (p1, p2) -> aux p1 @ [None, symbol "\\BELOW"] @ aux p2
+ | Above (p1, p2) -> aux p1 @ [None, symbol "\\ABOVE"] @ aux p2
+ | Frac (p1, p2) -> aux p1 @ [None, symbol "\\FRAC"] @ aux p2
+ | Atop (p1, p2) -> aux p1 @ [None, symbol "\\ATOP"] @ aux p2
+ | Over (p1, p2) -> aux p1 @ [None, symbol "\\OVER"] @ aux p2
+ | Root (p1, p2) ->
+ [None, symbol "\\ROOT"] @ aux p2 @ [None, symbol "\\OF"] @ aux p1
+ | Sqrt p -> [None, symbol "\\SQRT"] @ aux p
+ | Break -> []
+ | Box (_, pl) -> List.flatten (List.map aux pl)
+ and aux_magic =
+ function
+ Opt p ->
+ let (p_bindings, p_atoms) = List.split (aux p) in
+ let p_names = flatten_opt p_bindings in
+ [None,
+ Gramext.srules
+ [[Gramext.Sopt
+ (Gramext.srules
+ [p_atoms,
+ make_action (fun (env : env_type) (loc : location) -> env)
+ p_bindings])],
+ Gramext.action
+ (fun (env_opt : env_type option) (loc : location) ->
+ match env_opt with
+ Some env ->
+ List.map
+ (fun (name, (typ, v)) ->
+ name, (OptType typ, OptValue (Some v)))
+ env
+ | None ->
+ List.map
+ (fun (name, typ) -> name, (OptType typ, OptValue None))
+ p_names)]]
+ | _ -> assert false
+ and aux_variable =
+ function
+ NumVar s -> [Some (s, NumType), number ""]
+ | TermVar s -> [Some (s, TermType), term]
+ | IdentVar s -> [Some (s, StringType), ident ""]
+ | Ascription (p, s) -> assert false
+ | FreshVar _ -> assert false
+ in
+ aux pattern
+
+let level_of_int precedence =
+ if precedence mod 10 <> 0 || precedence < 0 || precedence > 100 then
+ raise (Level_not_found precedence);
+ string_of_int precedence
+
+type rule_id = Token.t Gramext.g_symbol list
+
+let extend level1_pattern ?(precedence = 0) =
+ fun ?associativity action ->
+ let (p_bindings, p_atoms) =
+ List.split (extract_term_production level1_pattern)
+ in
+ let level = level_of_int precedence in
+ let p_names = flatten_opt p_bindings in
+ let entry = Grammar.Entry.obj (l2_pattern : 'a Grammar.Entry.e) in
+ let _ =
+ prerr_endline (string_of_int (List.length p_bindings));
+ Grammar.extend
+ [entry, Some (Gramext.Level level),
+ [Some level, associativity,
+ [p_atoms,
+ make_action
+ (fun (env : env_type) (loc : location) -> action env loc)
+ p_bindings]]]
+ in
+ p_atoms
+
+let delete atoms = Grammar.delete_rule l2_pattern atoms
+
+let print_l2_pattern () =
+ Grammar.print_entry Format.std_formatter (Grammar.Entry.obj l2_pattern);
+ Format.pp_print_flush Format.std_formatter ();
+ flush stdout
+