Re: Nested immutable value objects

So does the Car class something like a copy constructor , where we give all the old values of the car , along with a new value for Fuel .. while constructing this new Car ?

If we run with this Example of Car with 4 tires and Fuel ... Can you show me how you're Car, Fuel and Tyre classes would look ?



--- In [email protected], Giacomo Tesio <giacomo@...> wrote:
>
> In C# I used delegate functions.
> 
> Something like car.WithFluel(fluel => fluel.Increase(100)), with
> Car.WithFluel() returning a new Car, and Fluel.Increase returning a new
> Fluel. Car.WithFluel is responsible to mix the variation in the values.
> 
> This works well as far as you don't have many levels of nested value
> objects: on the real world examples that I've met till now, I've needed at
> most 3 levels, and no one encountered problems while reading the code. Just
> remember to document all exceptions that each method does not handle (see
> http://epic.tesio.it/2013/03/04/exceptions-are-terms-ot-the-ubiquitous-language.html
> ).
> 
> 
> Giacomo
> 
> On Tue, Mar 19, 2013 at 7:19 AM, sudarshan89 <sudarshan89@...> wrote:
> 
> > **
> >
> >
> > am trying to wrap my head around modelling with immutable objects, while
> > doing so I am trying to understand how one would "update" a nested
> > immutable object.
> >
> > I will just present my case with a help of an example, A car is filling
> > fuel, this could be realized in code by creating a new car instance with a
> > added fuel (keeping the immutable objects in mind, i do not just want to
> > increment a counter) .
> >
> > So each time fuel is added I get a new car which has all the properties of
> > the old car but the fuel tank has more fuel.
> >
> > This sounds conceptually good however we I try to code it down. My car
> > would have a engine, tires and other immutable components, when a new car
> > is created the entire graph needs to re created and then put into this new
> > car, this would mean that i would need some kind of a copy constructor
> > within my car class.
> >
> > I was curious to know how such a case can be handled cleanly ...
> >
> > Thanks
> >
> >  
> >
>




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