From: Marek Janukowicz <childNOSPAM@...17.ds.pwr.wroc.pl>
Date: 2003-06-03T02:07:38+09:00
Subject: Re: Advantages of Symbols over constants

On Mon, 2 Jun 2003 10:23:16 +0900, Jim Weirich wrote:
>> One advantage of symbols is that they know how to print themselves, but 
>> you can of course get this advantage with constants that refer to symbols:
>> 
>>    UP = :up
>>    DOWN = :down
>> 
>>    x = UP
>>    puts "You are going #{x}"
>> 
>> Another advantage with constants is that, if you want to change the 
>> value, there's only one spot in the code to change and you don't break 
>> the API.
> Well, yes ... but I imagine that in the cases we are talking about the
> actual value of the constant is irrelevant.  In fact, if I were to use
> constants, I would consider doing ...
> 
>    UP = Object.new
>    DOWN = Object.new

Isn't it better to do eg.
	UP = 1
	DOWN = 2

This way you don't create new (and in fact unnecessary) objects.

> Now I can't accidently use :up or :down in my code.  I _must_ use the
> constant.
> 
> Since the value is unimportant, changing the value is unlikely. 
> However, it is possible that I later decide the constants should be
> named TOP and BOTTOM instead of UP and DOWN.  And this is a problem for
> both symbols and constants equally.

I read what you and the others wrote and I am now even more convinced I
should use constants in my program. 

Thanks for all answers
-- 
Marek Janukowicz