Re: Length of unbounded_string.

["Vinzent Hoefler" <0439279208b62c95f1880bf0f8776eeb@t-domaingrabbing.de>]

ldries46 wrote:

> In my program I use unbounded_string str
>
> I want to change the last character of the string using the program lines
>
> 2205  len := Length(str);
> 2206  Replace_Slice(str, len, len, "G");

This seems correct to me. Although I am not sure, where ARM A4.3(74.1/1) would
lead us here. ;)

> Then I get the following message printed in my exception part of the program
>
> Error type    : CONSTRAINT_ERROR
> In phase      : Step 1
> in function   : Continuation
> Error info    : trans2ada.adb:2206 range check failed
>
> file line nr  :  1
> Original line : /* GtkPrintJob
> Next line     :  * Copyright (C) 2006 John (J5) Palmieri  <johnp@redhat.com>
>
> In this print out the Original line represents "str".
>
> Is there a problem with the Length function or do I interpret something
> wrong?

Well, I can't reproduce the problem here. Test code was:

-- 8< --
     X := Ada.Strings.Unbounded.To_Unbounded_String ("ABCD");
     Y := Ada.Strings.Unbounded.Length (X);

     Ada.Strings.Unbounded.Replace_Slice (Source => X,
                                          Low    => Y,
                                          High   => Y,
                                          By     => "Z");
     Ada.Text_IO.Put_Line (Ada.Strings.Unbounded.To_String (X));
-- 8< --

It correctly prints "ABCZ".

Same compiler version, so it seems something is wrong in your part of the
code.

First thing that comes to mind is that maybe the string in question does not
have a lower bound of 1, but that's close to impossible with Unbounded_String.

Another idea: Maybe, the string's last character is a null character and
somethings gets garbled on the way between the C- and the Ada-world?


Vinzent.

-- 
f u cn rd ths, u cn gt a gd jb n cmptr prgrmmng.