Let me phrase question differently, after finding out that new is actually a class method of Class class, as is all methods of Class class.
m = Class.new creates an m object that has access to Class's class methods. So "new" created an object that has access to class methods in this case. Then why: n = m.new doesnt "new" create an object that gives n access to m's class methods, as it did in the other case? On Jan 21, 3:03 pm, John Merlino <stoici...@aol.com> wrote: > "Object is the root of Ruby's class hierarchy. Its methods are > available to all classes unless explicitly overridden." > > Wouldn't Class class be at the root of the class hierarchy? > > After all, look at this: > > 1.9.2p290 :006 > Object.instance_of? Class > => true > > Object is an instance of class, after all we can use one of Class' > instance methods on Object: > > 1.9.2p290 :017 > Object.new > => #<Object:0x007faad047ecd0> > > But Class is not instance of Object: > > 1.9.2p290 :007 > Class.instance_of? Object > => false > 1.9.2p290 :008 > defined? Class > => "constant" > 1.9.2p290 :009 > Class.class > => Class > 1.9.2p290 :010 > Object.class > => Class > > Class is an instance of Class. That is, Class is an instance of > itself. And therefore "Class" just is (kind of like the idea if > something stems from something else, how was the very first thing > created - it just was). Class is just an internal construct, built > part of the language for templating. > > So Object is a constant that represents an object allocated in memory. > When it's methods are searched for it looks up the scope chain, first > at the singleton class (just in case any methods are extended on > Object) and after that, it looks at its immediate parent which is > Class, and hence that's why we can say Object.new, since Class class > defines "new". > > Now this is the interesting part. There obviously is a difference > between Object and Class. As already stated, Object is an instance of > Class and therefore inherits from Clas, not visa versa. > > The difference is made clear as shown below: > > We have a constant "A". We want that constant to be a class, so we do > it easily: > > A = Class.new > > We know that A is a class because we can run A.new. > > However, when we create an object: > > B = Object.new > > This fails: > 1.9.2p290 :007 > B.new > NoMethodError: undefined method `new' for #<Object:0x007ff597d27820> > > When we instantiate B, the instance gets B's instance methods. But why > doesn't it get Class's instance method (new)? > > B inherits from Object which inherits from Class. It should have > looked up scope chain until it reached Class, since Object is an > instance of Class and therefore inherits from it. -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk@googlegroups.com. To unsubscribe from this group, send email to rubyonrails-talk+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
