Re: STRING length

[Georg Bauhaus <bauhaus@futureapps.de>]

On Tue, 2006-11-14 at 14:51 -0800, markww wrote:
> Hi,
> 
> How does one use a variable length string in ada?

You use variable length strings in Ada by declaring them
to be of type UNBOUNDED_STRING which is defined in
Ada.Strings.Unbounded. 

type MY_RECORD is
  record
    Name: UNBOUNDED_STRING;
    Phone: UNBOUNDED_STRING;
    Address: UNBOUNDED_STRING;
  end record;

Given that Phone is likely to be limited in length, you
could consider declaring the Phone component to be of
type BOUNDED_STRING, which is a string type with a maximum length.
Unlike STRING, objects of this type can have any number
of characters up to the maximum. See Ada.Strings.Bounded.

Yet another use of strings is in nested scopes: If you need
a string in just one place, e.g. temporarily, you can use
a plain STRING as in

  declare
    temp: constant STRING := some_string_returning_func(...);
  begin
    -- use temp
  end;

The point here is that the `temp` string variable takes
its bound from the initialization. You can also make it a
variable, if you need to write to string components.

See
http://en.wikibooks.org/wiki/Ada_Programming/Strings


-- Georg