Chip 2000 February/Chip_2000-02_cd.bin/zkuste/Delphi/navody/tt/objvm.exe/UNITS/LangVariable.pas

Pascal/Delphi Source File | 1998-06-27 | 2KB | 66 lines

unit LangVariable;

interface
uses LangValue;
type
       { Variable for language }
     TLangVariable=class(ILangValue)
     protected
        function  rdValues(const s:string):ILangValue;override;
     public
        Value:ILangValue;
        constructor Create;
        destructor  Destroy;override;
        procedure Exec(S:IValStack;MustReturn:boolean);override;
        function  HasValue(const s:string):boolean;override;
        function  CreateEqu:ILangValue;override;
     end;
implementation
uses VarLangValue,SysUtils,LangRef;
const cRef='Ref';
function  TLangVariable.rdValues;
          begin
            if S=cRef then
              Result:=TLangRef.Create(Self)
            else
              Result:=Value.Values[s];
          end;
procedure TLangVariable.Exec;
          begin
            if S.FrameCount>1 then
              raise Exception.Create('Try to assign more than 1 value');
            if S.FrameCount>0 then
            begin
              Value.Free;
              Value:=s.FrameValues[0].CreateEqu;
            end;
            s.DropFrame;
            if MustReturn then
            begin
              S.Push(Value.CreateEqu);
            end;
          end;
function  TLangVariable.HasValue;
          begin
            if s=cRef
            then
              Result:=true
            else
              Result:=Value.HasValue(s);
          end;
function  TLangVariable.CreateEqu;
          begin
            Result:=nil;
          end;
constructor TLangVariable.Create;
          begin
            inherited Create(nil);
            Value:=TVarLangValue.Create(nil);
          end;
destructor  TLangVariable.Destroy;
          begin
            Value.Free;
            inherited Destroy;
          end;
end.