ERRORS

PITFALLS
========

Here's some trouble that I've gotten into so far while programming with Nu.  
All of it is avoidable, and some of it might be preventable with future improvements.

* Trying to evaluate string expressions with (eval "expression"). 
  They should be parsed first. Parse them with the parse operator.
	
* Code can be unevaluated due to incompletely-balanced parentheses, 
  usually causing a class or method declaration to be left open.
  Nested classes and imethods should generate warnings.  
  An open sexpr at end of file should also be an error.

* Accidentally calling junk in the objc runtime like this deprecated class:
  [NSATSGlyphGenerator initialize] invocation.  The class is deprecated.

* There are also problems with classes that aren't inherited from NSObject.
  % (NSProxy alloc)
  2007-07-05 14:46:10.356 nush[435:807] exception NSInvalidArgumentException: *** -[NSProxy methodSignatureForSelector:] called!

* Releasing NSPlaceholder objects.  This usually causes a messy crash.  
  Currently, I keep a list of known placeholder classes and update it 
  whenever I trip over a new one. If there's an automated way to identify them, 
  I don't know what it is.

* Certain classes (like NSDate) crash when you do this: [[NSDate alloc] retain];  
  This happens as part of Nu (and RubyCocoa/RubyObjC) object management.  
  Three cheers for consistency.

* When I try to load code from a bundle without properly setting the bundle signature,
  the load fails.

* Return values can be messed up when I use results of methods with the wrong return 
  type (usually the problem is that the method is declared to return (void)).