Re: variable lenght strings

[fmdf@tiscali.it (fabio de francesco)]

"Matthew Heaney" <mheaney@on2.com> wrote in message news:<417842cd$0$74191$39cecf19@news.twtelecom.net>...

Hi,

I thank you all for your kind support, that is what you always give.
This is one more reason to be added to the enjoyment of learning Ada.

[CUT]

> The termination condition is as follows: you know that you've consumed the 
> entire line when Last < Line'Last.

Good! I didn't know.

[CUT]

> If you want, you can use recursion to read the line, and return the string 
> as a function result:
> 
> declare
>    function Get_Line (N : Positive := 80) return String is
>       Line : String (1 .. N + 1);
>       Last : Natural;
>    begin
>       Get_Line (Line, Last);
> 
>       if Last < Line'Last then
>         return Line (1 .. Last);
>       else
>          return Line & Get_Line (2 * N);
>       end if;
>    end Get_Line;
> 
>    Line : constant String := Get_Line;
> begin
> 
> This avoids the loop, and having to store intermediate results in a buffer.

I like the method you explained. I suppose that I have to change the
function name in order not to collide with the standard Get_Line. So I
renamed it My_Get_Line, but when compiling I get:



 22.              return Line & My_Get_Line (2 * N);
                                              |
        >>> ambiguous operand for concatenation
        >>> possible interpretation at line 13
        >>> possible interpretation at line 13

Line 13 is the line that starts My_Get_Line definition. Why is the
operand ambiguous?

Fabio De Francesco