On Sun, Jun 08, 2003 at 11:05:24PM -0700, Andres Valloud wrote:
> > I really don't see anything evil about Object>>isNumber or Object>>isString;
> > numbers and strings are core parts of the language and it seems fair enough
> > for an object to know it isn't one.
> 
> The bad part about these messages is that numbers and strings already
> "know" what they are by virtue of their behavior, and in the case of
> Smalltalk, by virtue of their class which specifies their behavior.  It
> would be even better to eliminate the isFoo + ifTrue/ifFalse construct
> with polymorphism, i.e.:
> 
> 	"in the context of doing foo"
> 	anObject isWhatever
> 		ifTrue: [this foo action]
> 		ifFalse: [that foo action]
> 
> becomes
> 
> 	"in the context of doing foo"
> 	anObject fooAction
> 
> where
> 
> 	Whatever>>fooAction
> 
> 		"this foo action"
> 
> 
> 	Object>>fooAction
> 
> 		"that foo action"
> 
> 
> On top of cleaner and more intention revealing code, you get speedups
> because it's no longer necessary to determine the value of a boolean
> expression at runtime using ifTrue/ifFalse.  The meaning is in the
> receiver - cf. how booleans are implemented.

But you might have a dozen methods with isFoo + ifTrue/ifFalse.  Then
you would need Object>>fooAction1, Object>>fooAction2, etc.

Joshua

> 
> Andres.