DataMuseum.dk

top - metrics - download

    Length: 5563 (0x15bb)
    Types: TextFile
    Names: »B«

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

TextFile

with Bounded_String;
with Block;
with Integer_Class;
with Msg_Report;
with Object;
with Scanner;
with String_Class;  
with String_Utilities;
with Symbol_Table;  
with Unparse_Report;
with Value;


package body Primary is

    procedure Bs_Copy (A_String : in out Scanner.B_String; A_Value : String)
        renames Bounded_String.Copy;

    function Bs_Image (A_String : Scanner.B_String) return String
        renames Bounded_String.Image;

    function Su_Capitalize (A_String : String) return String
        renames String_Utilities.Capitalize;

    function Su_Strip (From : String; Filler : Character := ' ') return String
        renames String_Utilities.Strip;

    type Node_Structure is
        record
            Rule : Natural range 0 .. 4 := 0;  
            Valu : Value.Node := Value.Empty_Node;  
            Bloc : Block.Node := Block.Empty_Node;  
            Iden : Scanner.B_String;
            Inte : Integer;  
            Stri : Scanner.B_String;
            Lign : Integer;
        end record;

    procedure Parse (N : in out Node; Error : out Boolean) is
        Failed : Boolean := False;  
        use Scanner;

    begin

        Msg_Report.Information ("I enter in primary's parse");

        N := new Node_Structure;

        N.Lign := Scanner.Line_Number;

        if Scanner.Symbol = L_Identifier then  
            Bs_Copy (N.Iden, Scanner.Value);
            N.Rule := 2;  
            Scanner.Next;
        else
            if Scanner.Symbol = L_Integer then
                N.Inte := Integer'Value (Scanner.Value);
                N.Rule := 3;  
                Scanner.Next;
            else
                if Scanner.Symbol = L_String then
                    Bs_Copy (N.Stri, Scanner.Value);
                    N.Rule := 4;  
                    Scanner.Next;
                else
                    if Scanner.Symbol = L_Open_Parenthesis then
                        Scanner.Next;  
                        if Value.Is_First (Scanner.Symbol) then  
                            Value.Parse (N.Valu, Failed);

                            if Scanner.Symbol /= L_Close_Parenthesis then
                                Failed := True;
                                Msg_Report.Syntax_Error (") expected, not ");
                            else
                                Scanner.Next;
                            end if;  
                        else  
                            Failed := True;
                            Msg_Report.Syntax_Error ("incorrect follow of ( :");
                        end if;
                    else
                        N.Rule := 1;
                        if Block.Is_First (Scanner.Symbol) then
                            Block.Parse (N.Bloc, Failed);  
                        else
                            Failed := True;
                            Msg_Report.Syntax_Error ("incorrect primary : ");
                        end if;
                    end if;
                end if;
            end if;
        end if;

        Msg_Report.Information ("I leave primary's parse with failed = " &
                                Boolean'Image (Failed));

        Error := Failed;
    end Parse;


    procedure Unparse (N : Node) is

    begin
        case N.Rule is

            when 0 =>
                Unparse_Report.Write ("( ");
                Value.Unparse (N.Valu);
                Unparse_Report.Write (") ");

            when 1 =>  
                Block.Unparse (N.Bloc);

            when 2 =>
                Unparse_Report.Write (Su_Capitalize (Bs_Image (N.Iden)) & " ");

            when 3 =>
                Unparse_Report.Write (Su_Strip (Integer'Image (N.Inte)) & " ");

            when 4 =>
                Unparse_Report.Write ("""");
                Unparse_Report.Write (Bs_Image (N.Stri));
                Unparse_Report.Write (""" ");

        end case;
    end Unparse;


    function Is_First (T : Scanner.Token) return Boolean is
        use Scanner;
    begin
        return T = L_Identifier or else T = L_Integer or else
                  T = L_String or else T = L_Open_Parenthesis or else
                  Block.Is_First (Scanner.Symbol);
    end Is_First;


    function Interpret (N : Node;
                        Inherited : Object.Reference := Object.Void_Reference)
                       return Object.Reference is

        Result : Object.Reference;
        use Object;

    begin

        Msg_Report.Information ("I enter in primary's interpret");

        Msg_Report.Set_Line_Number (N.Lign);

        case N.Rule is

            when 0 =>
                Result := Value.Interpret (N.Valu);

            when 1 =>
                Result := Block.Interpret (N.Bloc);

            when 2 =>  
                if Symbol_Table.Is_Found (N.Iden) then
                    Result := Symbol_Table.Get_Info (N.Iden);
                else
                    Msg_Report.Interpret_Error
                       ("variable " & Bs_Image (N.Iden) & " is undefined");

                    raise Undefined_Variable;
                end if;


            when 3 =>
                Result := Integer_Class.Create (N.Inte);


            when 4 =>
                Result := String_Class.Create (Bs_Image (N.Stri));

        end case;

        Msg_Report.Information ("I leave primary's interpret with result :");
        Msg_Report.Continue
           ("class = " & Object.Class'Image (Object.The_Class (Result)) &
            " ident = " & Integer'Image (Object.Identificator (Result)));

        return Result;
    end Interpret;
end Primary;