require 'book_cmp'

ary = []
ary << Book.new("Software", "Rucker", "SF")
ary << Book.new("BABEL-17", "Delany", "SF")
ary << Book.new("Programming Perl",   "Wall",  "Computer")
ary << Book.new("Programming Pearls", "Bentley", "Computer")

ary.sort.each{|book|
  printf "%-10s %-20s %s\n", book.genre, book.title, book.author
}