From: John Sikora <john.sikora@...>
Date: 2010-10-14T15:21:21+09:00
Subject: Re: setting local variables in a binding

By the way, I've been busy and not checking the forums too much lately.
However, I just noticed the concurrent thread of:

sort_by: multiple fields with reverse sort.

http://www.ruby-forum.com/topic/224672#new

In my world I would do:

class B < EnumerableObjectClass::Base
  attr_accessor :field_1, :field_0, :field_2  # sets default sort order.

  def initialize(field_0, field_1, field_2)
    super()
    @field_0, @field_1, @field_2 = field_0, field_1, field_2
  end
end

B.new("radio", 30, 5)
B.new("radio", 20, 5)
B.new("archie", 20, 5)
B.new("newton", 10, 3)

# default sort - :field_1, field_0, field_2 order, normal direction.
p B.enum{}.sort.collect(:field_0, :field_1, :field_2)
# => [["newton", 10, 3], ["archie", 20, 5], ["radio", 20, 5], ["radio",
30, 5]]

# sort by field_1 reverse, field_0 normal (same as the OP 3rd sort_by in
that thread).
p B.enum{}.sort(':field_1___', :field_0).collect(:field_0, :field_1,
:field_2)
# => [["radio", 30, 5], ["archie", 20, 5], ["radio", 20, 5], ["newton",
10, 3]]

# sort by field_0 reverse, field_2 normal, field_1 reverse.
p B.enum{}.sort(':field_0___', :field_2,
':field_1___').collect(:field_0, :field_1, :field_2)
# => [["radio", 30, 5], ["radio", 20, 5], ["newton", 10, 3], ["archie",
20, 5]]

Easy! Note the triple underscore suffix denotes reverse order sorting
for that parameter. But this code uses the evil eval.

js

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