count_string program

[Cecilia Chew <cecilia@nowhere.com>]

Hi all,
I am doing a program that will count the input characters from user. 
There is a problem that I can't solve.
Problem is : since I'm going to count the characters. So, I can't ask 
user how many characters they want to input. Compilation error come and 
mention that the string need to be constrainted.
How am I going to constraint the string type since I don't know how many 
characters user going to input.

Program is as follow:

========================================================================
with Ada.Text_Io, Ada.Integer_Text_Io;
use Ada.Text_Io, Ada.Integer_Text_Io;

procedure Count_String is
    type String is array (Positive range <>) of Character;
    Input : String;
    Count : Integer;
begin
    Count := 0;
    Put ("Please enter a string :");
    for I in Input'Range loop
       Get(Input(I));
       Count := Count + 1;
    end loop;
    New_Line;
    Put ("There are" & Integer'Image(Count) & " characters");
end Count_String;
=========================================================================

Problem occured at   input : string;
with compilation error: unconstrainted subtype not allowed.
Please give any comments to this program. Thank you.

-- 

Cecilia Chew
c e c i l i a <AT> g r e e n l i m e . c o m