with Text_io, IIO; use Text_io;

procedure FIBO is -- Calculate Fibonaci's Numbers - using Tasks

 
  package IIO is new Text_IO.Integer_io(integer); --need integer output

  function FIBONACI(N:POSITIVE) return POSITIVE; --hides a neat trick
 
 
  task type FIBS_NUMBER is

    entry Get(ID:POSITIVE; F:out positive);-- ID identifes which number

    entry STOP;

  end FIBS_NUMBER;

 
  MAX:constant:=30;
 
  subtype INDEX is INTEGER range 1..19;
  FIB:array(INDEX) of FIBS_NUMBER;
  N:NATURAL; F:POSITIVE;
 
 
  task body FIBS_NUMBER is separate;
 -- source in fibonaci.sub
 
  function FIBONACI(N:POSITIVE)return POSITIVE is
        F:POSITIVE;
  begin
	if N not in INDEX then Put("FIBONACI not implemented");
		raise numeric_error;
	end if;
       FIB(N).Get(N,F);
       return F;
  end FIBONACI;
 
begin 

  loop

     Put("Input a number (0 to stop): "); iio.Get(N);
     exit when N=0;
     New_Line;
     F:=FIBONACI(N);
     Put("Fib("); iio.Put(N); Put(")=");iio.PUT(F);New_Line;
  end loop;

 
  Put("MAIN STOP");

 
  for N in FIB'RANGE loop FIB(N).STOP;
  end loop;
end FIBO;