RE: Implementing an elegant range type.

[Francisco Javier Loma Daza <Francisco.Loma@isotrol.com>]

El 20 Mar 2001 15:17:29 -0500, Beard, Frank escribi�:
> 
> -----Original Message-----
> From: Chad R. Meiners [mailto:crmeiners@hotmail.com]
> 
> >> Why not just write:
> >>
> >>     type Integer_Range is record
> >>         First, Last : Integer;
> >>     end record;
> >>
> 
> > For example, the operator I want to use is "in" and not "Length".
> > I want to be able to write "If x in Switches_To_Be_Reserved'Range then
> ..." 
> 
> Whether you use Mark's example above, or pass in the First and Last 
> as parameters, you can still write the following:
> 
> 
>    Assuming "Reserved_Range : in Integer_Range", as the formal argument
> passed in.
> 
>    if x in Reserved_Range.First .. Reserved_Range.Last then ...
> 
> 
> or, using Range_First and Range_Last as the formal parameters:
> 
>    Range_First : in integer;
>    Range_Last  : in integer;
> 
>    if x in Range_First .. Range_Last then ...
> 
> 
> I agree it might be slightly more elegant to pass a single parameter
> so that the statement would be:
> 
>    if x in Reserved_Range then
> 
> but you're only saving one parameter, since "in" works for discrete types.
> 
> Frank


    This is an interesting way to do range operations. I would like to
    do this one:

    function Iterator(this: Container.Object) return Container.Range;


    declare
        r: Container.Range := Iterator(list);
    begin
        for x in r'Range loop
            Process(Item(list, x));
        end loop;
    end;

    ...... even better

            Process(list(x)); -- :-)