From: ptkwt@...1.aracnet.com (Phil Tomson)
Date: 2002-02-03T07:55:57+09:00
Subject: Re: Variable types

In article <3C5C3842.4010307@imperitek.com>,
David Corbin  <dcorbin@imperitek.com> wrote:
>I know I'm new to ruby, but I feel obligated to share my dislike for 
>"special symbols" to indicate if a symbol is a member, local variable or 
>global variable.  Perhaps I don't know enough to make such a comment, 
>and someone will show me my mistunderstanding.  

Well, it sounds like you understand how it works but you just don't like 
it ;-)  

Give it a few more weeks.  Where you came from language-wise will 
influence this:
* If you came from Perl you're probably thinking "An '@' should indicate 
an array not an instance variable and a '$' is for scalars..."
* If you came from C/C++ you're wondering why we use any symbols at all.
 
So, compared to Perl, Ruby uses a lot less sigils so they actually tend to 
stand out in your code more instead of being drowned out in the noise.

Also, consider the alternatives:

In Python in order to use an instance variable you have to use 'self':

  self.var

In Ruby it's:
  @var

The '@' is a lot shorter and to me it tends to stick out more in the code 
so that I can tell at a glance it's an instance var.
(I'm not sure how Python does globals)

In other languages you might have to declare a global like:

global type var

But how do you know the scope of 'var' when you see it later on in the 
code?  The '$' prefix in Ruby is a nice way to tell 'at a glance' that var 
is global.

So that's basically it: Ruby's way of indicating scope is concise and it's 
easy to read once you're used to it.  Give it a few weeks, you'll get used 
to it and probably you'll start to appreciate it.

Phil