Re: RFE: Enumerable#group_by, Array#^

Hi,

> Comments, suggestions, notes and so on are very welcome.



I use something similar but for bidimensional arrays. Though I use the
RAA Arrayfields library.

It's not very tested, and it's kind of old already so I don't even
remember all of it. Here it goes:

require 'arrayfields'

class Array
  def order_by *indices
    if size < 0 or self[0].class != Array
      return self
    end
    ff = self[0].fields
    if not ff 
      ff = []
    end
    indices.map!{|c| c.class == Symbol ? ff.index(c) : c}
    indices.map!{|c| 
      if c.class == String and c.to_i.to_s != c 
        i = ff.index(c)
        if not i
          i = ff.index(c.to_sym)
        end
        i.to_s
      else
       c
      end
    }
    if indices.select{|i| i.class == String}.size == 0
      sort_by{|r| r.values_at(*indices)}
    else
      sort{|ar,br| 
        v = 0
        indices.each{|i| 
          if i.class == String
            v = br[i.to_i] <=> ar[i.to_i]
          else
            v = ar[i] <=> br[i]
          end
          if v.nonzero?
            break
          end
        }
        v
      }
    end
  end
end


Bear with any nonsense in this code, please. :-)

Cheers,
Joao