From: "Peter C. Verhage" <usenet2@...>
Date: 2004-09-14T18:04:54+09:00
Subject: Re: JRuby article

James Britt wrote:
> (I confess I have not taken the time to read the article, only skim it. 
>  But the $camelCase stuff jumped out.  There may be a good reason to use 
> globals, perhaps related to having to deal with some Java stuff; the 
> company you keep and all that.  Otherwise, though, some of the code 
> looks bad.)

Yes, they have a good reason for it. In JRuby it doesn't seem possible 
to create a Ruby class which directly inherits from a Java class.

 From the article:
"The next bit of code may seem unusual to the Java programmer. We first 
define a global variable for the main calculator window by prefixing the 
identifier with a dollar sign ($). This class definition is known as an 
anonymous class in JRuby. Essentially, we want to create a class based 
on or inheriting from the object we've just created. (Due to limitations 
in the implementation of inheritance in JRuby, we cannot define a class 
that directly inherits from a Java class.) In defining our new subclass, 
we write an init method (since the initialize method has already been 
called in the creation of the $calculator object). We will need to call 
this method upon completing the class definition. (To some extent, this 
is akin to calling super() in a Java class constructor and then 
proceeding with the initialization of that class.)"

Regards,

Peter