Re: Tally

[Jere <jhb.chat@gmail.com>]

On Wednesday, January 15, 2020 at 4:03:14 AM UTC-5, Simon Wright wrote:
> Brad Moore  writes:
> 
> >    for Number of Input loop
> >       Counts (Number) := Counts (Number) + 1;
> >    end loop;
> 
>    for Number of Input loop
>       if Counts.Contains (Number) then
>          Counts (Number) := Counts (Number) + 1;
>       else
>          Counts.Insert (Number, 1);
>       end if;
>    end loop;
> 
> and then of course
> 
>    for C in Counts.Iterate loop
>       Put_Line (Count_Maps.Key (C)'Image
>                   & " -> "
>                   & Count_Maps.Element (C)'Image);
>    end loop;

I might recommend using insert every iteration and seeing if
it fails or succeeds.  Since it gives a cursor regardless of
success, you can use that get the element and avoid doing
all the searches each time:

    for Number of Input loop
    
        -- Try to insert a new element.  This will 
        -- fail if the element already exists
        Counts.Insert
            (Key => Number,
             New_Item => 1,
             Position => Position,
             Inserted => Inserted);
    
        -- Since the element already exists, simply
        -- increment the count
        if not inserted then
            Counts(Position) := Counts(Position) + 1;
        end if;

    end loop;