Yes it does, thanks. It is amazing how much you can do in the typical spring/hibernate stack with a decent IDE without engaging your brain :).
Clojure involves far less ceremony and really does expose you to the raw elements of your problem domain and make you think. This is of course a good thing, but boy is it quite humbling :). No more procrastinating by setting up JPA and thinking long and hard about "Java, Annotations or good old XML?". I am definitely at the stage where I think Clojure's simplicity is very hard (according to Rich's "simple made easy" talk). Not implying Clojure's simplicity is only the lack of ceremonial frameworks! Loving it, and yes, looking back I can see how easy it is to lose your solution amongst the staggering amount of incidental complexity. I guess my (rambling) point is to reiterate that it is very easy to plaster over symptoms/effects using the very powerful framework beasts. The lack of them forces you to think, and hopefully remove the cause. Finally, I have worked with some fantastic developers who happen to use Java to build incredibly elegant and transparent solutions. I have just worked with far more code monkeys, myself being one of them :). On 11 May 2013 08:21, "Sean Corfield" <seancorfi...@gmail.com> wrote: > Korny mentioned java.jdbc and I figured that was a good in to talk > about how we use it at World Singles. Even with the old API we used a > function in a specific namespace that returned the data source (in > fact it returned a pooled data source, using c3p0). Behind the scenes, > we actually use an atom to provide a cached, singleton instance. > with-redefs allows us to mock that for testing, if needed :) > > I haven't missed DI at all since moving to Clojure - after decades of > OO - and I still use it in the non-Clojure, OO code that could be > considered our "legacy" system that wraps our Clojure code. > > Clojure makes me think about my dependencies and organize them in a > very clean top-to-bottom tree, with very clear divisions between > subsystems. In the OO world, DI makes you sloppy... You can have > circular dependencies. You can easily add whatever dependencies you > need. You don't have to think about it, you can work around problems > that crop up. > > Does that help Colin? > > Sean > > On Fri, May 10, 2013 at 4:04 AM, Colin Yates <colin.ya...@gmail.com> > wrote: > > (newbie, getting better each day!) > > > > I assume we all know DI. Through the use of a central registry I can > > register a service (a bean in a Spring bean factory for example). I also > > define consumers of that service in the same registry passing in the > > configured *instance* of that service. > > > > In Clojure I have a service (i.e. a datasource) defined in its own > > namespace. What is idiomatic Clojure?: > > > > 1) to use (defonce *data-source*...) so that every body who requires > that > > ns gets the same instance? > > 2) to provide a 'get-ds' accessor which returns a new instance and rely > on > > passing that service along to every function that needs it? > > 3) some other way I don't know about > > > > Option 1 seems to be less-typing, but now functions aren't pure - they > > depend upon state defined elsewhere. I can change the binding through > > 'with-XYZ' type functions, but that isn't solving the non-explicit > > dependency between the function and the state. > > > > Option 2 means functions are still pure, but how do you prevent huge > lists > > of services - i.e. if func-a calls func-b which calls func-c and func-c > > needs service-a then func-a and func-b need to access service-a. Yuck. > It > > also means the main entry point to my application needs to assemble all > of > > these services up in one go. > > > > To be more explicit - DI containers provide a graphs of logic coupled > with > > state - the state being the instances of the collaborators (i.e. "I will > > have ConsumerA with an instance of SimpleServiceA please"). Clojure has > > very strong opinions about how to manage state. > > > > How does the Clojure community handle this use case of separating out the > > definition of a service, the configuration of that service and providing > > that service as a collaborator to a consumer? > > > > Thanks a bunch. > > > > Col > > > > -- > > -- > > You received this message because you are subscribed to the Google > > Groups "Clojure" group. > > To post to this group, send email to clojure@googlegroups.com > > Note that posts from new members are moderated - please be patient with > your > > first post. > > To unsubscribe from this group, send email to > > clojure+unsubscr...@googlegroups.com > > For more options, visit this group at > > http://groups.google.com/group/clojure?hl=en > > --- > > You received this message because you are subscribed to the Google Groups > > "Clojure" group. > > To unsubscribe from this group and stop receiving emails from it, send an > > email to clojure+unsubscr...@googlegroups.com. > > For more options, visit https://groups.google.com/groups/opt_out. > > > > > > > > -- > Sean A Corfield -- (904) 302-SEAN > An Architect's View -- http://corfield.org/ > World Singles, LLC. -- http://worldsingles.com/ > > "Perfection is the enemy of the good." > -- Gustave Flaubert, French realist novelist (1821-1880) > > -- > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to clojure@googlegroups.com > Note that posts from new members are moderated - please be patient with > your first post. > To unsubscribe from this group, send email to > clojure+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/clojure?hl=en > --- > You received this message because you are subscribed to a topic in the > Google Groups "Clojure" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/clojure/keid7IGzKjk/unsubscribe?hl=en. > To unsubscribe from this group and all its topics, send an email to > clojure+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
