Re: Another Idea for Ada 20XX

[Patrick Hohmeyer <pi3_1415926536@yahoo.ca>]

And Lutz Donnerhacke has spoken :

> * James Rogers wrote:
> >In scientific terms a measurement is done in terms of some unit.
> >For instance, distance is in meters, microns, feet or furlongs.
> >Speed is then calculated as a distance per unit time. Acceleration
> >is the second derivative of speed.
> 
> >Note that a lot of the unit analysis could be performed statically.
> >This would allow minimal performance penalty at run time.
> 
> http://www.iks-jena.de/mitarb/lutz/ada/units/
> 
> I�m going to provide automatic unit optimization. Please stay tuned.

Interesting approach, but at first glance I dont see how 
you'll solve the Celsius = Kelvin + 273.15 problem.

This solution seams only to work with units where zero in one unit
equals zero in the other as well.

I think an approach :

type Conversion is access function(value : Accuracy) return Accuracy;

type Unit_Description is record
      toSI : Conversion;
      fromSI : Conversion;
      -- some text ???
end record;

type Quantity is tagged record
      value : Accuracy;
      Unit : Unit_Description;
end record;

offers more flexibility than your idea of a Dimension.

-- 
Patrick Hohmeyer