Re: Random Input-Size and recognizing ENTER-press

[Jeffrey Carter <spam@spam.com>]

Marius Amado Alves wrote:

>    function Get_String return String is
>       U : Unbounded_String;
>    begin
>       loop
>          Get_Immediate (C);
>          exit when C = CR;
>          Append (U, C);
>       end loop;
>       return To_String (U);
>    end;

You might want to take a look at the source for Ada.Strings.Unbounded 
from GNAT before advocating an approach such as this. Every addition of 
a Character allocates a new String, copies the old String + new 
Character into the new String, and deallocates the old String. For a 
string of N Characters, that's N allocations and deallocations. Using 
Get_Line to obtain the Characters can improve that to N / Buffer'Length + 1.

It's not clear that the OP really requires Get_Immediate; the only 
requirement stated is the need to read an arbitrary-length String. The 
discussion of recognizing when the Enter key is pressed is part of a 
proposed solution, not the problem.

-- 
Jeff Carter
"C++: The power, elegance and simplicity of a hand grenade."
Ole-Hjalmar Kristensen
90