From: Frank Tao <dalfrank@...>
Date: 2008-12-03T01:27:01+09:00
Subject: dynamic programming

# I have a class Adam
# I want to modify the method("m_a") so that it will return the cached
result
# If no cached result is available, then return the original result
# I want to create a class method(AKA: macro) to make it DRY
#
# So far, I have issues like
# 1) dynmically define class variable
# 2) failed to include a module inside a method of a class
#
# Any suggestion or comments will be appreciated
#
class Adam
  def self.m_a
    ["Adam#m_a"]
  end
end

class CachedAdam
  caching_method :adam, :m_a

  def self.caching_method
    # this method should do something to make the following codes
  end
end


## CachedAdam#caching_method should make and load the following codes
#
# module AdamWithCache
#   def m_a_with_cache
#     CachedAdam.get_cached_m_a || m_a_without_cache
#   end
#   def self.include(base)
#     base.alias_method_chain :m_a, :cache
#   end
# end
# Adam.class_eval{ include AdamWithCache }
#
# class CachedAdam
#   def self.get_cached_m_a( adam_id )
#     @@cache && @@cache[adam_id]
#   end
#
#   def self.set_cached_m_a(hash_list)
#     hash_list.each do |k,v|
#       @@cache ||={}  # failed, any suggestion?
#       @@cache[k] = v
#     end
#   end
# end
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