How do you do something like this?

class Fruit
{

protected struct _Eigen
{
byte color = GREEN;
bool rotten = false;
}
private _Eigen eigen;

this(...)
{
 // ?
}

}

apple=new Fruit(color=RED,rotten=false);
apple2=new Fruit(rotten=true);
apple3=new Fruit(pit=false); //pit=ignored

Saaa wrote:
> How do you do something like this?
> 
> class Fruit
> {
> 
> protected struct _Eigen
> {
> byte color = GREEN;
> bool rotten = false;
> }
> private _Eigen eigen;
> 
> this(...)
> {
>  // ?
> }
> 
> }
> 
> apple=new Fruit(color=RED,rotten=false);
> apple2=new Fruit(rotten=true);
> apple3=new Fruit(pit=false); //pit=ignored
> 
> 
> 

class Fruit
{

   protected struct _Eigen
   {
      byte color = GREEN;
      bool rotten = false;
   }

    private _Eigen eigen;

    this()
    {
    }

    this(bool rotten, byte color)
    {
         eigen.rotten = rotten;
         eigen.color = color;
    }
}

auto apple = new Fruit( false, RED );
auto normal = new Fruit();

Thanks for your reply.
But I think  I wasn't clear in my question.
As _Eigen can get quite large I think it is necessary to have something
like:

apple=new Fruit(color=RED,rotten=false);

otherwise thinks like this will happen:

apple=new Fruit(,,,RED,,false,,true etc.);





>
> class Fruit
> {
>
>    protected struct _Eigen
>    {
>       byte color = GREEN;
>       bool rotten = false;
>    }
>
>     private _Eigen eigen;
>
>     this()
>     {
>     }
>
>     this(bool rotten, byte color)
>     {
>          eigen.rotten = rotten;
>          eigen.color = color;
>     }
> }
>
> auto apple = new Fruit( false, RED );
> auto normal = new Fruit();

Not directly you can do something like

struct test
{
  bool A;
  int B;
  float C;
}

class foo
{
  private test t;

  this(test bar)
  {
   t = bar;
  }
}

void main()
{
  static test t = { A:true, C:4.5 };
  foo f = new foo( t);

}

But the static struct has to be filled by constants..

But it sounds like you might be better off using inheritance..
create a base Fruit class that you inherit and modify needed data..




Saaa wrote:
> Thanks for your reply.
> But I think  I wasn't clear in my question.
> As _Eigen can get quite large I think it is necessary to have something like:
> 
> apple=new Fruit(color=RED,rotten=false);
> 
> otherwise thinks like this will happen:
> 
> apple=new Fruit(,,,RED,,false,,true etc.);
> 
> 
> 
> 
> 
>> class Fruit
>> {
>>
>>    protected struct _Eigen
>>    {
>>       byte color = GREEN;
>>       bool rotten = false;
>>    }
>>
>>     private _Eigen eigen;
>>
>>     this()
>>     {
>>     }
>>
>>     this(bool rotten, byte color)
>>     {
>>          eigen.rotten = rotten;
>>          eigen.color = color;
>>     }
>> }
>>
>> auto apple = new Fruit( false, RED );
>> auto normal = new Fruit(); 
> 
> 

>
> But the static struct has to be filled by constants..
Yeah, not too usefull for my program :)

>
> But it sounds like you might be better off using inheritance.. create a base Fruit class that you inherit and modify needed data..
>

Will that not take just as much code as modifying the needed data within the
objects?
Or aren't I getting it :)
All permutations of possible settings should be possible.

This will work, but is maybe a tad eleborate :)

apple=new Fruit("color",RED,"rotten",false);

Saaa wrote:
> This will work, but is maybe a tad eleborate :)
> 
> apple=new Fruit("color",RED,"rotten",false);
> 
> 
> 
> 

Two more thoughts...

Use with. not as clean looking and requires write access to data
http://www.digitalmars.com/d/1.0/statement.html#WithStatement

Foo = new Fruit;
with(Foo)
{
  rotten = true;
  color = YELLOW;
  taste = SWEET;
  bitesLeft = nBites; //variable
}


the other is a mixin, I've never really messed with them but something like below..  But the string has to be evaluated at compile time...
http://www.digitalmars.com/d/1.0/statement.html#MixinStatement


badBerry = new Fruit( "rotten = true; color = BLUE" );

class Fruit
{

   this(const char[] type)
   {
     mixin(type);
   }

.....

Thanks, I was looking at mixin myself but the compile time evaluating didn't
work for me.
I totally forgot about 'with', might at least make it more compacted
together.

I just wanted it like in R .. :)