Re: [Q] Returning Strings From A Function

["Joakim Olsson" <joakim.h.olsson@swipnet.se>]

John McCabe <john@assen.demon.co.uk> wrote in article
<33454165.1658515@news.demon.co.uk>...
> Hello all.
> 
> I hope someone can help me as how to do this has completely slipped my
> mind, and I'm having trouble finding what I'm looking for in the Ada
> LRM (83) and Barnes.
> 
> I have a function, let's call it Text_IO.Name which returns a string.
> If I have an object let's say File_Name, what would be the correct (or
> best) way to declare that object in order for the statement:
> 
> File_Name := Text_IO.Name (File);
> 
> (or something similar with slices?) to work without me getting a
> constraint error by trying to assign a string of n characters to an
> object /=n characters long.
> 
> Should I be using subtypes here or what.
> 
> I'm sure this will appear to be a really stupid question, but at the
> moment I'm being frustrated and I can't think straight!
> 
> Thanks in advance.
> 
> 
> Best Regards
> John McCabe <john@assen.demon.co.uk>


Hi John.

If you declare 'File_Name' as constant STRING it should work.
Using a constant declaration should work in Ada83 and Ada95,
but if I not remember things wrong, You don't have to have the
constant declaration in Ada95...


Example:

-- procedure or function
--
procedure Proc is
   File_Name : constant STRING := Text_IO.Name (File);
begin
.....
.....
end;

-- declarationblock inside a procedure or function
--
procedure Proc is
begin
   declare
      File_Name : constant STRING := Text_IO.Name (File);
   begin
      -- File_Name exists of course only in this block
      .....
      .....
   end;
.....
.....
end;

Se You, safe and sound hacking Ada...
/Jake