Re: :symbol vs CONSTANT choice

On 08/17/2012 07:50 AM, Robert Klemme wrote:
> On Thu, Aug 16, 2012 at 11:37 PM, Charles Hixson
> <[e-mail]>  wrote:
>    
>> I have a list of about 12 items that I wish to repeatedly store as part of a
>> record in a file.  The obvious way to do this is to define a bunch of
>> constant terms with values [1 .. 12].  But when I want to use them in the
>> program, symbols would be more convenient.  Is there a better way to do this
>> than just defining the constants, and using a pair of functions to convert
>> to and from symbols?
>>      
> There are some approaches to do enums in Ruby out there, e.g.
> http://code.dblock.org/how-to-define-enums-in-ruby
> http://stackoverflow.com/questions/75759/enums-in-ruby
> http://www.lesismore.co.za/rubyenums.html
>
> You'll find plenty more with your favorite search engine.
>
> Other than that the two function approach probably works as well.  Or
> you use two Hashes for both directions and not two functions.
>
> Kind regards
>
> robert
>    
Thanks.  I pulled two versions of enum out of those links, that look 
like they might be what I want.  It will be a couple of weeks yet, and I 
don't know whether the bit manipulation version (class) will be what I 
need or whether I'll go with the simpler (module) version.  One of them 
will clearly be more suited to the situation than just defining a bunch 
of constants.

Of course, since I don't need anything this general, I *could* just 
define a class with a bunch of read accessors to class level variables, 
and no write accessor.  Initialize them with constant values.  ...  
Well, it would work, but it feels really sloppy.  With the enum methods 
I can add a to_s that does what I want, and a to_i that does what I 
want, so I could store them cheaply in a database, and print them out in 
a meaningful form.  (This means I don't want to exactly use either of 
the two best solutions you pointed me at, but a customized variation.    
But that's relatively a small change.)

-- 
Charles Hixson