Comments on: Sustainable Development in Ruby, Part 1: Good Old-Fashioned Inheritance http://avdi.org/devblog/2008/03/27/sustainable-development-in-ruby-part-1-good-old-fashioned-inheritance/ Sat, 19 Jul 2008 20:23:25 +0000 http://wordpress.org/?v=2.3.1 By: Enfranchised Mind » 7 Actually Useful Things You Didn’t Know Static Typing Could Do: An Introduction for the Dynamic Language Enthusiast http://avdi.org/devblog/2008/03/27/sustainable-development-in-ruby-part-1-good-old-fashioned-inheritance/#comment-51 Enfranchised Mind » 7 Actually Useful Things You Didn’t Know Static Typing Could Do: An Introduction for the Dynamic Language Enthusiast Mon, 14 Apr 2008 14:49:48 +0000 http://avdi.org/devblog/2008/03/27/sustainable-development-in-ruby-part-1-good-old-fashioned-inheritance/#comment-51 [...] This is certainly a leap and a bound beyond global duck punching, where you need to know how every use of that module is going to behave, and then validate that it works out in all those cases. The reality in my experience is that people who pull off global duck punching tend to just kind of pray and hope their unit tests catch any bug they just introduced. This makes me unoptomistic about the maintainability of that code — and even the Ruby community is starting to agree with me (cite, cite). [...] […] This is certainly a leap and a bound beyond global duck punching, where you need to know how every use of that module is going to behave, and then validate that it works out in all those cases. The reality in my experience is that people who pull off global duck punching tend to just kind of pray and hope their unit tests catch any bug they just introduced. This makes me unoptomistic about the maintainability of that code — and even the Ruby community is starting to agree with me (cite, cite). […]

]]> By: This Week in Ruby (April 7, 2008) | Zen and the Art of Programming http://avdi.org/devblog/2008/03/27/sustainable-development-in-ruby-part-1-good-old-fashioned-inheritance/#comment-39 This Week in Ruby (April 7, 2008) | Zen and the Art of Programming Mon, 07 Apr 2008 10:07:25 +0000 http://avdi.org/devblog/2008/03/27/sustainable-development-in-ruby-part-1-good-old-fashioned-inheritance/#comment-39 [...] Development in Ruby (part 1 and part [...] […] Development in Ruby (part 1 and part […]

]]> By: Virtuous Code › Sustainable Development in Ruby, Part 2: Method Injection http://avdi.org/devblog/2008/03/27/sustainable-development-in-ruby-part-1-good-old-fashioned-inheritance/#comment-27 Virtuous Code › Sustainable Development in Ruby, Part 2: Method Injection Tue, 01 Apr 2008 02:00:12 +0000 http://avdi.org/devblog/2008/03/27/sustainable-development-in-ruby-part-1-good-old-fashioned-inheritance/#comment-27 [...] fields are marked * Name * Email * Website Comment add_openid_to_comment_form() ‹ Sustainable Development in Ruby, Part 1: Good Old-Fashioned Inheritance © 2008 ¶ Thanks, WordPress. ¶ veryplaintxt theme by Scott Allan Wallick. [...] […] fields are marked * Name * Email * Website Comment add_openid_to_comment_form() ‹ Sustainable Development in Ruby, Part 1: Good Old-Fashioned Inheritance © 2008 ¶ Thanks, WordPress. ¶ veryplaintxt theme by Scott Allan Wallick. […]

]]> By: avdi http://avdi.org/devblog/2008/03/27/sustainable-development-in-ruby-part-1-good-old-fashioned-inheritance/#comment-26 avdi Sat, 29 Mar 2008 21:37:26 +0000 http://avdi.org/devblog/2008/03/27/sustainable-development-in-ruby-part-1-good-old-fashioned-inheritance/#comment-26 Pat: I understand your point, but this was the inheritance post :-) Composition will come later. Pat: I understand your point, but this was the inheritance post :-) Composition will come later.

]]> By: Pat Maddox http://avdi.org/devblog/2008/03/27/sustainable-development-in-ruby-part-1-good-old-fashioned-inheritance/#comment-25 Pat Maddox Sat, 29 Mar 2008 21:05:57 +0000 http://avdi.org/devblog/2008/03/27/sustainable-development-in-ruby-part-1-good-old-fashioned-inheritance/#comment-25 I think this is a perfect example of where to prefer composition over inheritance. I would probably do: <code>class BufferedReader def initialize(connection) @connection = connection end def receive buffer = "" begin message = @connection.receive buffer << message.data end until(message.data.include?("ENDENDEND")) Message.new(buffer) end end</code> This allows you to combine different readers to achieve the behavior you want. Not only that, but now the buffered reader is generally useful instead of being coupled to the Connection class. I think this is a perfect example of where to prefer composition over inheritance. I would probably do:

class BufferedReader
def initialize(connection)
@connection = connection
end

def receive
buffer = “”
begin
message = @connection.receive
buffer << message.data
end until(message.data.include?(“ENDENDEND”))
Message.new(buffer)
end
end

This allows you to combine different readers to achieve the behavior you want. Not only that, but now the buffered reader is generally useful instead of being coupled to the Connection class.

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