Re: N best things about Ada?

[Shark8 <onewingedshark@gmail.com>]

On Jul 12, 9:13 am, Robert A Duff <bobd...@shell01.TheWorld.com>
wrote:
> Shark8 <onewingedsh...@gmail.com> writes:
> > People have mentioned packages, non-textual-substitution generics, and
> > such.
> > But one thing that could come in handy is the named parameters, and it
> > is something I like; one of those "little things."
>
> Yes.  It's such a small feature, yet has a huge benefit.
> People should use it more often.
>
> Another small feature: underscores in numeric literals.
> One of my pet peeves is when I have to carefully
> count the zeroes in 10000000, when it's so easy
> to write 10_000_000.
>
> > "Circle( Radius => 23, X => 28, Y => 14 );" will always be more
> > readable than "Circle( 23, 28, 14 );" plus, there's the added benefit
> > that 1) changes in parameter-ordering will not impact calls of this
> > sort, & 2) the users of the functions/procedures can place the more
> > pertinent parameters [to their task] more prominently [e.g. first].
>
> Do you have any examples of that last part?  That is, examples
> where using different parameter orders in different calls
> makes the code more readable?
>
> I think that sort of inconsistency usually makes the code less readable.
> I wouldn't mind a rule that says the parameter order has to match
> the declaration.  (A Legality Rule, not a Name Resolution Rule!)
>
> - Bob

Well, in image-manipulation there are a number of formats that store
their information Y, then X. (That is they use column-major order
instead of row-major order.)

Given a call:
 "Get_Pixel(K,J);"
Is that in familiar X-Y space, or in the image's native Y-X space?

Get_Pixel( X=> K, Y=> J);
and
Get_Pixel( Y=> J, X=> K);
are unambiguous, and given the situation/problem you may be thinking
in
one or the other.

Let's say you were to want to extend/overload Get_Pixel for a Point-
type:
 Type Point_Type is record
  Y, X : Integer;
 end record;

You could write it as:
Function Get_Pixel( Point : Point_Type ) return Pixel_Value is
begin
 Return Get_Pixel( X=> Point.X, Y=> Point.Y);
end;