>From what I've heard, you are absolutely right on those globals. It isn't considered idiomatic and should be avoided, like in all other languages. The singleton analogy fits pretty good.
Some advice on how to encapsulate state in a sane way can be found for example here: http://vimeo.com/46163090 I think the global vars in those libs were mostly for convenience while programming and *could* be removed by thinking through the alternatives. On Wednesday, September 12, 2012 4:30:54 PM UTC+2, the80srobot wrote: > > Hello, > > So I've been working on a project at work, that required me to code a > simple web interface. I considered going with Noir, and while reading the > code, I noticed a pattern that seems to repeat throughout most of the code > that Chris Granger has published in Clojure. This is what I'm referring to: > > ; these are at the top level in (ns noir.core) > (defonce noir-routes (atom {})) > (defonce route-funcs (atom {})) > (defonce pre-routes (atom (sorted-map))) > (defonce post-routes (atom [])) > (defonce compojure-routes (atom [])) > > Now, I am new to Clojure, but I am not new to (functional) programming and > I'd like to think that I know a singleton when I see one. Is that really > what these are? If I'm right then defining your 'globals' (for lack of a > better word) like this would mean, among other things, that you really > can't have two independent Noir apps defined/running in the same project - > is that a correct assessment? > > Can someone more experienced shed some light on why it's done this way? My > experience in functional programming has taught me to always limit my scope > - I would think that either using thread-local bindings (and then rebinding > them to child threads) or relying on lexical scope would be preferable to > polluting the global state. Is this a Clojure best practice? > > Thanks. I'm looking to use Clojure a lot at work, and I'm trying to really > understand the language before I throw it our production problems. > > ~Adam > -- 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
