Re: Length of unbounded_string.

[Jeffrey Carter <spam.jrcarter.not@spam.not.acm.org>]

On 10/25/2011 02:37 AM, ldries46 wrote:
> I just found the following extra relevant points:
> Instead of <Str := Str & " " & Next_Line;> I put in the line <Str := Str & "x "
> & Next_Line;>
> This showed that with Str := "str," en Next_Line := "Next" the output became
> "str x Next"
> When I changed Str to Str := "strx" the output changed to "strxx Next"
> This looks like the comma has a special meaning within an Unbounded String

No Character has a special meaning in a String or an Unbounded_String. This 
appears to be a problem with the way you're viewing the contents.

with Ada.Strings.Unbounded;
with Ada.Text_IO;

procedure US_Test is
    use Ada.Strings.Unbounded;

    Str_Start : constant Unbounded_String := To_Unbounded_String ("str,");
    Next_Line : constant Unbounded_String := To_Unbounded_String ("Next");

    Str : Unbounded_String := Str_Start;
begin -- US_Test
    Str := Str & " " & Next_Line;
    Ada.Text_IO.Put_Line (Item => '>' & To_String (Str) & '<');
    Str := Str_Start;
    Str := Str & "x " & Next_Line;
    Ada.Text_IO.Put_Line (Item => '>' & To_String (Str) & '<');
    Str := To_Unbounded_String ("strx");
    Str := Str & "x " & Next_Line;
    Ada.Text_IO.Put_Line (Item => '>' & To_String (Str) & '<');
end US_Test;

jrcarter@jrcarter-gateway-1:~/Code$ gnatmake -gnaton -O2 -j2 us_test.adb
gcc-4.4 -c -gnaton -O2 us_test.adb
gnatbind -x us_test.ali
gnatlink us_test.ali
jrcarter@jrcarter-gateway-1:~/Code$ ./us_test
 >str, Next<
 >str,x Next<
 >strxx Next<

This is GNAT 4.4.5 on Ubuntu 11.04. If this program gives different results on 
your system, let us know.

-- 
Jeff Carter
"Blessed are they who convert their neighbors'
oxen, for they shall inhibit their girth."
Monty Python's Life of Brian
83