[stringtemplate-interest] difficulty using format and null options together

[Terence Parr]

On Mar 20, 2008, at 6:55 PM, John Snyders wrote:
> I wonder if the following would work.
> When the null option is used the string value is wrapped in a class  
> such
> as NullDefault. This simple class acts much like a string and toString
> just renders the wrapped string. So because of the way ST default
> rendering works it should just call toString and get the intended
> default value. When the NullDefault object is passed to the format
> renderer it will be able to distinguish it from a normal string. This
> could still have some backward compatibility problems depending on if
> people wrote robust renderers that called toString on objects they
> didn't recognize.
>
> Terence, what do you think? Is this worth doing or will it cause  
> problems?

very interesting John.  Your thing that I'm wondering about is the  
fact that the null argument can actually be a template not just a  
string. In his case he could use maybe null={NULL} instead of  
null="NULL" and then distinguish string from the template...or if you  
is doing that check, why can't he just check for "NULL"?

Ter