Comments on: Enumerations and Ruby

By: dB.

dB. — Wed, 16 Mar 2011 21:50:46 +0000

Let’s make some small changes and make this Enum structure reusable – http://code.dblock.org/ShowPost.aspx?id=184.

By: Sidy Diop

Sidy Diop — Thu, 22 Apr 2010 00:27:35 +0000

Hi,
Another thing you could do (if you just need the integer values of associated symbols) is:
Colors = [ RED = 0, YELLOW = 1, GREEN = 3]
Then you can just loop doing: COLORS.each do { |x| do_something x }
You can access COLORS[RED]. Of course, COLORS would be a global if you need it everywhere. But again, you can encapsulate it in a module if you wish.

By: Brent

Brent — Wed, 19 Aug 2009 20:46:51 +0000

very helpful (even comments), thanks!!

By: jeff

jeff — Wed, 15 Jul 2009 01:06:32 +0000

Might also take a look at enumerated_attribute: http://github.com/jeffp/enumerated_attribute/tree/master. It works like…

enum_attr :gear, %w(reverse ^neutral first second third)

By: Frank

Frank — Thu, 25 Jun 2009 00:47:19 +0000

Hey Thanks for the links!

By: Karlin Fox

Karlin Fox — Wed, 24 Jun 2009 19:16:09 +0000

You may also be interested in Enumeration: http://github.com/karlin/enumeration/tree/master

By: Allex

Allex — Thu, 03 Jan 2008 20:03:59 +0000

Look at Renum - "a Ruby enum gem".

By: Frank

Frank — Mon, 27 Aug 2007 16:11:16 +0000

Alex,

That’s a good question. Instead of using a Fixnum as the value, you could use a Hash :

class Status
Complete={:value => 0, :string => “complete”}
Queued={:value => 1, :string => “queued”}
Ready={:value => 2, :string => “ready”}
Processing={:value => 3, :string => “processing”}
Waiting={:value => 4, :string => “waiting”}
end

status = Status::Waiting
status[:value] # output : 4
status[:string] # output : waiting

There might be better ways to achieve what you want, but I think this solution would work fine.

By: Alex Egg

Alex Egg — Sat, 25 Aug 2007 06:10:54 +0000

Consider this enum of the style you describe:

class Status
Complete=0
Queued=1
Ready=2
Processing=3
Waiting=4
end

now say I have an instance of this status:

status=Status::Waiting

How could I get this as a string that says “Waiting”? Even thought status is 4. Maybe create a class method in Status called to_string or something?

By: Frank

Frank — Thu, 12 Jul 2007 21:44:11 +0000

Yes, you are right siroj. The enum described in this article was not an enum in the pure sense of the word… as it isn’t a “type” per se.

Most of the time, I only need the kind of enum described in this article… or I don’t need an enum at all. I just like to “group names under a common namespace” for code readability. I rarely need something fancier.

Thanks for your comment