DataMuseum.dk

Presents historical artifacts from the history of:

Rational R1000/400 Tapes

This is an automatic "excavation" of a thematic subset of
artifacts from Datamuseum.dk's BitArchive.

See our Wiki for more about Rational R1000/400 Tapes

Excavated with: AutoArchaeologist - Free & Open Source Software.


top - download
Index: ┃ B T

⟦6b97ed259⟧ TextFile

    Length: 2046 (0x7fe)
    Types: TextFile
    Names: »B«

Derivation

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

TextFile

with Message;
with Value, Block;
with Bug_Report;

package body Expression is

    type Node_Structure is
        record
            Rule : Natural range 0 .. 1 := 0;
            Val : Value.Node := Value.Empty_Node;
            Ident : Message.Unary;
        end record;

    procedure Parse (N : in out Node) is
        use Scanner;
    begin  
        N := new Node_Structure;
        if Value.Is_First (Scanner.Get_Token) then
            N.Rule := 0;
            Value.Parse (N.Val);
        else
            if Scanner.Get_Token = Scanner.Pour then
                N.Rule := 1;
                Scanner.Next;
                if Scanner.Get_Token = Scanner.Identifier then
                    Message.Put (This_Name => Scanner.Get_Value,
                                 Into => N.Ident);
                    Scanner.Next;  
                else
                    raise Bug_Report.Identifier_Is_Missing;
                end if;
                if Scanner.Get_Token = Scanner.Prendre then
                    Scanner.Next;
                    Value.Parse (N.Val);
                else
                    raise Bug_Report.Prendre_Is_Missing;
                end if;
            else
                raise Bug_Report.Unexpected_Token;
            end if;
        end if;
    end Parse;

    function Is_First (T : Scanner.Token) return Boolean is
        use Scanner;
    begin
        return T = Pour or else Value.Is_First (T);
    end Is_First;

    function Interpret (N : Node) return Object.Reference is
        Result : Object.Reference;
        Node : Block.Node := Block.Get_Current_Node;
    begin
        case N.Rule is
            when 0 =>
                Result := Value.Interpret (N.Val);
            when 1 =>
                Result := Value.Interpret (N.Val);
                Block.Put_Into_Table (This_Object => Result,
                                      Named => Message.Get (N.Ident),
                                      Into_Block => Node);
        end case;
        return Result;
    end Interpret;
end Expression;