/// <summary>
/// Bind 'this'
/// </summary>
/// <param name="instance">The instance</param>
/// <returns></returns>
public LoxFunction Bind(LoxInstance instance)
{
LoxEnvironment environment = new LoxEnvironment(_closure);
environment.Define("this", instance);
return(new LoxFunction(_declaration, environment, _is_initializer));
}
public object Call(Interpreter interpreter, IList <object> arguments)
{
LoxInstance instance = new LoxInstance(this);
// Constructor
LoxFunction initializer = _methods.Get("init");
if (initializer != null)
{
initializer.Bind(instance).Call(interpreter, arguments);
}
return(instance);
}
public LoxFunction FindMethod(LoxInstance instance, string name)
{
if (_methods.ContainsKey(name))
{
return(_methods.Get(name).Bind(instance));
}
// Check the superclass if we are inherited
if (this.Superclass != null)
{
return(this.Superclass.FindMethod(instance, name));
}
return(null);
}
public object Visit(Expr.Super expr)
{
// Look up the superclass
int? distance = _locals.Get(expr);
LoxClass superclass = (LoxClass)_environment.GetAt(distance.Value, "super");
// "this" is always one level nearer than "super"
LoxInstance obj = (LoxInstance)_environment.GetAt(distance.Value - 1, "this");
// Lookup the method
LoxFunction method = superclass.FindMethod(obj, expr.Method.Lexeme);
if (method == null)
{
throw new RuntimeErrorException(expr.Method, $"Undefined property '{expr.Method.Lexeme}'.");
}
return(method);
}