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    Length: 3444 (0xd74)
    Types: TextFile
    Names: »B«

└─⟦a7d1ea751⟧ Bits:30000550 8mm tape, Rational 1000, !users!projects 94_04_11
    └─⟦129cab021⟧ »DATA« 
        └─⟦this⟧ 

TextFile

with Bounded_String;  
with Error_Broadcaster;
with Lex;
with Object;
with Bloc;
with Bloc_Class;
with Value;
with Unparser;
package body Primary is
    type Node_Structure is
        record
            Rule : Natural range 0 .. 3 := 0;
            Ident : Object.Message;
            Bl : Bloc.Node := Bloc.Empty_Node;
            Val : Value.Node := Value.Empty_Node;
            Obj : Object.Reference := Object.Void_Reference;
        end record;

    procedure Parse (N : in out Node; Error : out Boolean) is
        Failed : Boolean := False;
    begin
        N := new Node_Structure;  
        case Lex.Get_Token is
            when Lex.Open_Bracket =>  
                N.Rule := 0;
                N.Obj := Object.Create (Lex.Get_Token, Lex.Get_Value);
                Bloc.Parse (N.Bl, Failed);
            when Lex.Integer =>  
                N.Rule := 1;
                N.Obj := Object.Create (Lex.Get_Token, Lex.Get_Value);
                Lex.Next_Token;  
            when Lex.Tiny_String =>
                N.Rule := 1;
                N.Obj := Object.Create (Lex.Get_Token, Lex.Get_Value);
                Lex.Next_Token;
            when Lex.Identifier =>
                N.Rule := 2;
                Bounded_String.Copy (N.Ident, Lex.Get_Value);  
                Lex.Next_Token;
            when Lex.Open_Parenthesis =>  
                N.Rule := 3;
                Lex.Next_Token;
                Value.Parse (N.Val, Failed);
                if Lex.Token'Pos (Lex.Get_Token) =
                   Lex.Token'Pos (Lex.Close_Parenthesis) then
                    Lex.Next_Token;
                else
                    raise Error_Broadcaster.Parenthesis_Is_Missing;
                end if;
            when Lex.Avec | Lex.Binary_Message | Lex.Key_Word |
                 Lex.L_End | Lex.Ok | Lex.Pour | Lex.Prendre |
                 Lex.Renvoyer | Lex.Special | Lex.Close_Parenthesis |
                 Lex.Unknown | Lex.Dot | Lex.Close_Bracket =>
                raise Error_Broadcaster.Unexpected_Token;
        end case;  
        Error := Failed;  
    end Parse;

    procedure Unparse (N : in out Node) is  
    begin
        case N.Rule is
            when 0 =>
                Bloc.Unparse (N.Bl);
            when 1 =>
                Unparser.Put (N.Obj.Identity);
            when 2 =>
                Unparser.Put (Bounded_String.Image (N.Ident));  
                Unparser.Put (" ");
            when 3 =>
                Unparser.Put ("(");
                Value.Unparse (N.Val);
                Unparser.Put (") ");
        end case;
    end Unparse;

    function Is_First (T : Lex.Token) return Boolean is
        use Lex;
    begin
        return T = Lex.Integer or else T = Lex.Tiny_String or else
                  T = Lex.Identifier or else
                  T = Lex.Open_Parenthesis or else Bloc.Is_First (T);
    end Is_First;

    function Interpret (N : Node;
                        Inherited : Object.Reference := Object.Void_Reference)
                       return Object.Reference is
        Result : Object.Reference;
    begin
        case N.Rule is
            when 0 =>
                Result := N.Obj;
            when 1 =>
                Result := N.Obj;
            when 2 =>
                Result := Bloc_Class.Get (N.Ident);
            when 3 =>
                Result := Value.Interpret (N.Val, Result);
        end case;
        return Result;
    end Interpret;
end Primary;