Unit Conversion Driver

last.rb

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# The two small modules here are intended to contain generic facilities
# which can be used by classes.

# This follows using the next method until we get to the end of whatever it
# is.
module Follower
  def last
    at = self
    while true
      n = at.next
      if n == nil then return at end
      at = n
    end
  end
end

# This prints on one line using the each method.
module Printer
  def pr(newline = false)
    self.each { |x| print x, " " }
    print "\n" if newline
  end
end

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Modules can be used to provide generic facilities using the include facility. The methods in the modules (well, one each in this case) can be added to classes using the include keyword. See the next page for its use.

Unit Conversion Driver

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