From: Paul <prcorcoran@...>
Date: 2006-08-24T07:20:06+09:00
Subject: OrderedHash - How to get it to work

First a bit of a rant. I CAN'T BELIEVE RUBY HASN'T IMPLEMENTED THIS!!!

Ok.. I feel better now. I am used to a verrry rich set of collection
classes in Smalltalk.

I know there has been a lot of discussion on this lately but I noticed
that the folks over at http://raa.ruby-lang.org/project/orderedhash/
have produced a class for us! It supports a pretty robust protocol.

However, if you download the gem and install it, it will error out. I
get a "superclass mismatch for class OrderedHash" error when my rails
controller gets loaded.

It turns out that rails also defined this class in it's initialize.rb
package. Burned on a namespace collision! Therefore, we can't use
OrderedHash as it's packaged from raa.ruby-lang.org. My solution was to
rename the ordered_hash.rb package to raa_ordered_hash.rb and then
rename the OrderedHash class within it to RaaOrderedClass.

Here is the full procedure I used.

1. Download the "GoodLibs-1.2006.07.13.gem" file from here:
http://raa.ruby-lang.org/project/orderedhash/
2. Run "gem install GoodLibs-1.2006.07.13.gem" from the directory you
downloaded it to.
3. Rename ordered_hash.rb to raa_ordered_hash.rb in the
"ruby\lib\ruby\gems\1.8\gems\GoodLibs-1.2006.07.13\lib" directory.
4. Edit the raa_ordered_hash.rb file and change the class to
RaaOrderedHash (in several places).
5. Use it in your code as follows:
    require 'rubygems'
    require 'raa_ordered_hash'
    BOOKCHAPTERS = RaaOrderedHash["MAT", 28, "MAR", 16, "LUK", 24,
"JOH", 21]
    BOOKCHAPTERS.each do |key, value| puts key +"," + value.to_s  end

    MAT,28
    MAR,16
    LUK,24
    JOH,21

6. Restart you server

If someone has a better way let me know.

Thanks,
Paul