From: Jim Freeze <jim@...>
Date: 2002-12-13T07:26:54+09:00
Subject: Inheritance Question

Hi

I am subclassing the Matrix class, and am having 
difficulty getting 'self' for the derived class.
Consider the example below:

module MyMatrix
  require 'matrix'
  class Matrix < ::Matrix
    def add_col(c)
      c.to_a.each_with_index { |e,i| @rows[i] << e }
      self
    end
#    def inv
#      inv
#      self  # this doesn't work either
#    end
  end
end

include MyMatrix
m = MyMatrix::Matrix[[1,2],[3,4]]
puts m.type
puts m.to_f.inv.type

 === output
MyMatrix::Matrix
Matrix

How do I get self to be 'MyMatrix' so I can
chain methods, such as:

  m.inv.add_col(c)  ?
                               


Thanks


-- 
Jim Freeze
----------
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