Traits

(not yet done) http://www.iam.unibe.ch/~scg/Research/Traits/

Example:

trait TCircle[T] {
  require {
    Radius () : int;
    Rotate (x : int) : T;
  }

  provide {
    Diameter () : int
    {
      Radius () * 2
    }

    RevRotate (x : int) : T
    {
      Rotate (-x)
    }
  }
}

This should translate to:

interface TCircle[T] 
  where T : TCircle[T] 
{
  Radius () : int;
  Rotate (x : int) : T;
  Diameter () : int;
  RevRotate (x : int) : T;

  static impl_Diameter (_this : T) : int
  {
    _this.Radius () * 2
  }
  
  static impl_RevRotate (_this : T, x : int) : T
  {
    _this.Rotate (-x)
  }
}

and later:

class SomeCircle 
{
  uses TCircle;
  public Radius () : int { 42 }
  public Rotate (_ : x) : SomeCircle { this }
}

to:

class SomeCircle : TCircle[SomeCircle] 
{
  public Radius () : int { 42 }
  public Rotate (_ : x) : SomeCircle { this }
  public Diameter () : int { TCircle[SomeCircle].impl_Diameter (this) }
  public RevRotate (x : int) : int { 
    TCircle[SomeCircle].impl_RevRotate (this, x) 
  }
}

Think about removing conflicts.