Sorry I wasn't more clear - I'm not talking about defonce, but about having
refs (atoms) defined at the top level. When they're defined like this, they
basically become global variables, don't they? Having two Noir apps would
then mean they share the same routes, among other things. Or am I missing
something?
On Wednesday, September 12, 2012 4:49:34 PM UTC+2, Jim foo.bar wrote:
>
> defonce simply means "do not bind the var if it already has a root
> value"... I think it only applies when reloading your namespace...to be
> honest, I'm not sure why Chris has coded it like that (creating an atom
> is not really expensive), but i find it hard to believe that you can' t
> have 2 Noir apps on the same project...basically defonce it is the same
> as def unless there is already a root value for that var...
>
> can anyone else add anything?
>
> Jim
>
>
> On 12/09/12 15:30, 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 clo...@googlegroups.com<javascript:>
> > Note that posts from new members are moderated - please be patient
> > with your first post.
> > To unsubscribe from this group, send email to
> > clojure+u...@googlegroups.com <javascript:>
> > 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 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
