Ruby: Module, Mixins and Blocks confusing?

Question

Following is the code I tried to run from the Ruby Programming Book http://www.ruby-doc.org/docs/ProgrammingRuby/html/tut_modules.html

Why doesn\'t the

Answer 1

In response to @zeronone "How can we avoid such namespace clashes?"

Avoid monkeypatching core classes wherever possible is the first rule. A better way to do this (IMO) would be to subclass Array:

class MyArray < Array
  include Inject 
  # or you could just dispense with the module and define this directly.
end


xs = MyArray.new([1, 2, 3, 4, 5])
# => [1, 2, 3, 4, 5]
xs.sum
# => 15
xs.product
# => 120
[1, 2, 3, 4, 5].product
# => [[1], [2], [3], [4], [5]]

Ruby may be an OO language, but because it is so dynamic sometimes (I find) subclassing gets forgotten as a useful way to do things, and hence there is an over reliance on the basic data structures of Array, Hash and String, which then leads to far too much re-opening of these classes.