class String
def push(other)
newself = self + other.to_s.dup.shift.to_s
self.replace(newself)
end
def shift
return nil if self.empty?
item=self[0]
self.sub!(/^./,"")
return nil if item.nil?
item.chr
end
end
a = "this is a test"
puts (a.push "another")