public IEnumerable <Context> GetContexts(Context context, ArgumentList arguments)
{
int count = arguments.Count;
if (count == 1)
{
yield return(context);
}
else
{
if (count == 2 && !arguments.IsNamed(1))
{
// Called with a new context.
yield return(context.CreateChild(arguments [1].Evaluate(context)));
}
else
{
// Called with 2 or more named parameters.
var nestedContext = context.Clone();
for (int i = 1; i < count; i++)
{
var name = arguments.GetName(i);
nestedContext.SetLocalVariable(name, arguments [i].Evaluate(context));
}
yield return(nestedContext);
}
}
}