class string 
{
  delegates
  {
    Stack[char] : f;
  }
  fields 
  {
    stack[char] f;  
  }
  public 
  {
    def _init(cstring x) {
      while (x != NULL) {
        push(*x++);
      };
    }    
    def _eq(self& x) : self& {
      clear();
      _plus_eq(x);
      return *this;
    }
    def _plus_eq(self& x) : self& {
      uint i=0;
      while (i < x.count()) {
        push(x[i]);
      };
      return *this;
    }
    def _plus(self& x) : self {
      return *this += x;      
    }
  }     
}

The _eq, _plus, and _plus_eq functions are operator overloads. The _init function is the constructor. There are a few extra neccessary semicolons (why they are needed is a very long story related to the future ability to pass code-blocks to macros).

The delegation specification automatically generates functions which forward an interface's required functions to a member field.

The latest version of HeronFront is very unstable, but I posted it to http://www.heron-language.com/downloads.html for anyone who might be using the HeronFront / YARD code base for their own work.