It’s far better for performance to have a ready-to-use instance of the object that we can share across the system. In this case, the lazy instantiation strategy works very well.

An instance variable differs from a local variable in the nature of its scope and its lifetime. The entire class makes up the scope of an instance variable, not the method in which it was declared.

In 1.7 we stopped caching the wrappers for Java objects that enter Ruby, and introduced warnings for two cases that could be affected: creating a singleton object from one of these wrappers setting ...