test1.txt

对pl0语言的词法分析程序

CONST A:=10; 
  var  B,C;  
      procedure P;   
        var D;
         procedure Q; 
           var X;
           begin
             read(X);
             D:=X;
             while X#0 
             do call P;
           end;
        begin
          write(D);
          call Q;
        end;
        begin
          call P;
        end.