DataMuseum.dk

top - download

    Length: 1467 (0x5bb)
    Types: TextFile
    Names: »B«

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

TextFile

with Scanner;
with Object;
with Unary;

package body More_Binary is

    type Node_Structure is
        record
            Rule : Natural range 0 .. 1 := 0;
            Unar : Unary.Node := Unary.Empty_Node;
            More : More_Binary.Node := More_Binary.Empty_Node;
            Mess : Object.Binary;
        end record;

    procedure Parse (N : in out Node; Error : out Boolean) is
        Failed : Boolean := False;
        use Scanner;
    begin  
        N := new Node_Structure;
        N.Rule := 0;
        Object.Put (Scanner.Get_Value, N.Mess);
        Scanner.Next;
        Unary.Parse (N.Unar, Failed);
        if not Failed and then Scanner.Get_Token = Scanner.Binary then
            N.Rule := 1;
            More_Binary.Parse (N.More, Failed);
        end if;
        Error := Failed;
    end Parse;

    function Is_First (T : Scanner.Token) return Boolean is
        use Scanner;
    begin
        return T = Scanner.Binary;
    end Is_First;

    function Interpret (N : Node;
                        Inherited : Object.Reference := Object.Void_Reference)
                       return Object.Reference is
        Result : Object.Reference;
    begin
        Result := Unary.Interpret (N.Unar);
        Object.Put (Result, N.Mess);
        Result := Object.Send (N.Mess, Inherited);
        if N.Rule = 1 then
            Result := More_Binary.Interpret (N.More, Result);
        end if;
        return Result;
    end Interpret;
end More_Binary;