new iterators in python and ruby

each_one.py

# from discussion of bring the block to the iterator at
# http://mettadore.com/ruby/ruby-blocks-seeking-closure/

## Ruby Version
'''
class Kids < Array
  def each_one
    self.each_with_index do |n, i|
      yield(n)
      p "Going now to tuck in #{self[i+1]}" if i < (self.length - 1)
      p "Everyone all snuggled up!" if i == (self.length - 1)
    end
  end
end
 
kids = Kids.new
 
%w(Wendy Michael John).each{|n| kids << n}
 
kids.each_one do |n|
 p "Tucking in #{n}"
end
'''


## python version, seems nearly as readable
## both seem to shift all the work onto 'make a new kind of iterator'
class Kids(list):
    def each_one(self):
        L = len(self)
        for (i,k) in enumerate(self):
            yield k
            if i < (L-1):
                print "Going now to tuck in %r" % (self[i+1])
            else:
                print "Everyone all snuggled up!"


kids = Kids("Wendy Michael John".split())
for k in kids.each_one():
    print "Tucking in %s" % k