Re: Length of unbounded_string.

[Niklas Holsti <niklas.holsti@tidorum.invalid>]

On 11-10-19 04:38 , ldries46 wrote:
> The complete code of which I would conclude that the comma should be
> present is:

    [ snip ]

 >    nr := nr + 1;
 >    ch := Element(Next_Line,    -- Next_LIne is a unbounded_string
 >          that can be connected to str

The assignment to ch is incomplete, there should be something after the 
comma. Looking at the loop below, I guess the statement is meant to be

    ch := Element(Next_Line, 1);

Also, at this point in the code, Next_Line has not been given any value, 
it has not even been declared. Is it a global variable? What does it 
contain when your problem occurs?

 >  while ch = ' ' or ch = ASCII.HT loop
 >     Replace_Slice(Next_Line, 1, 1, "");
 >     ch := Element(Next_Line, 1);
 >  end loop;

That loop will end badly if Next_Line contains only whitespace. You 
should exit the loop when the Replace_Slice makes Next_Line a null string.

> str := str & " " & -- After this statement the error is found by the
>        display function of the GDB
> Original_Line := -- Original Line is only meant for the error messges

Both those statements are syntactically incomplete. The first one ends 
with an operator "&"; there should be at least one more operand, and a 
terminating semicolon. The second one ends with ":=".

 >     Next_Line := To_Unbounded_String("");

You should exit the outer loop ("while not ok") at this point, I think, 
because otherwise you can loop back to the statement

    ch := Element(Next_Line, 1);

with Next_Line holding a null string, which is an indexing error.

I notice that you check for tab characters (HT). Can it happen that the 
string contains backspace characters? If the string has a comma, then a 
backspace, the comma is perhaps not visible on the screen when the 
string is displayed.

-- 
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
       .      @       .