Re: [Help-smalltalk] Using Smalltalk as a scripting language

[Paolo Bonzini]

On 10/28/2009 03:25 AM, Roland Plüss wrote:
> - void showBacktrace( FILE* ):
> This function is mentioned in the documentation at the website but does
> not exist in gstpub.h . It sounds to me like this function could be used
> to print out errors if there is a problem in the scripts somewhere, is
> that right? Is this also one of the new functions not found in the
> smalltalk version I have?

All of them are.

> If not what is the preferred way to handle
> errors? hijacking #doesNotUnderstand in the Object class ( including
> #halt and company )?

Hijacking SystemExceptions.UnhandledException>>#defaultAction sounds better.

Even better would be to define #debuggerClass in the superclasses that 
your scripts are supposed to subclass.  The #debuggerClass will be sent 
the class method #open:.

> - testing for nil:
> I want for example test if a given class exist. I do
> gst_class_name_to_oop( "AppTest" ) for example. Now assuming the class
> does not exist does this call return nilOOP? If so how do I properly
> test for nilOOP? Using objectIsKindOf (OOP, OOP)? ( asking since in the
> docs it's mentioned that IS_NIL macro is deprecated )

You can test "x == gst_interpreter_proxy.nilOOP".  You can of course 
define your own IS_NIL macro.  However gst_class_name_to_oop returns 
NULL (not nil) if the class is not found; I'll update the docs.

Paolo