Re: how do I reference a var that is in my core namespace?
That worked. I find it a little surprising that this is the correct way to
do this, but it worked, so I am happy. Thank you.
On Thursday, February 21, 2013 1:43:18 PM UTC-5, Sean Corfield wrote:
>
> I tend to have this at the top of most of my namespaces:
>
> (def ^:private my-ns *ns*)
>
> This evaluates *ns* at load/init time when it is bound to the
> namespace being loaded and then initializes my-ns with that value.
> Then I use my-ns throughout that namespace.
>
> *ns* is dynamically bound to whatever namespace is currently executing
> which is why it changes "unexpectedly" when you're trying to do
> something obvious with it.
>
> On Thu, Feb 21, 2013 at 10:30 AM, larry google groups
> > wrote:
> > I wanted to have some functions run when an app starts, and I wanted
> this to
> > be configurable, because I plan to use the same architecture for several
> > apps. So I thought I could have the function names as strings inside of
> maps
> > inside of a set (that I sort), in a config file. And I thought I could
> use
> > ns-resolve *ns* symbol to turn the strings into references to the vars
> where
> > the function definitions are stored. But somehow this is not working. I
> have
> > this right now, in mpdv.core, which is the core namespace is an app I
> > created with lein:
> >
> >
> > (defn process-startup-hooks []
> > "2013-02-21- remember, each row in hooks is a map: {:order-of-events
> 1,
> > :event-name 'connect-to-database'}"
> > (connect-to-database)
> > (let [hooks (sort-by :order-of-events
> > (:events-called-when-the-app-starts-hooks @um/interactions))]
> > (doseq [x hooks]
> > (let [event-as-symbol (symbol (:event-name x))
> > event (ns-resolve *ns* event-as-symbol)]
> > (println " what kind of var is this? ")
> > (println *ns*)
> > (println (type event-as-symbol))
> > (println event-as-symbol)
> > (if-not (nil? event)
> > (event))
> >
> >
> > "event" is always nil. One of the events listed in um/interactions is
> > "connect-to-database" so, as a test, I hardcoded it here, to be sure it
> > could run here, and it runs fine (first line after the comment). So the
> var
> > for the function is known. But this:
> >
> > (ns-resolve *ns* event-as-symbol)
> >
> > returns nil, even when event-as-symbol is "connect-to-database".
> >
> > When I println *ns* to the terminal output, I see the namespace is:
> >
> > #
> >
> > Which surprises me somewhat.
> >
> > How do I get ns-resolve to look in mpdv.core for the var that I want it
> to
> > find?
> >
> > --
> > --
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> >
> >
>
>
>
> --
> 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)
>
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Re: how do I reference a var that is in my core namespace?
I tend to have this at the top of most of my namespaces:
(def ^:private my-ns *ns*)
This evaluates *ns* at load/init time when it is bound to the
namespace being loaded and then initializes my-ns with that value.
Then I use my-ns throughout that namespace.
*ns* is dynamically bound to whatever namespace is currently executing
which is why it changes "unexpectedly" when you're trying to do
something obvious with it.
On Thu, Feb 21, 2013 at 10:30 AM, larry google groups
wrote:
> I wanted to have some functions run when an app starts, and I wanted this to
> be configurable, because I plan to use the same architecture for several
> apps. So I thought I could have the function names as strings inside of maps
> inside of a set (that I sort), in a config file. And I thought I could use
> ns-resolve *ns* symbol to turn the strings into references to the vars where
> the function definitions are stored. But somehow this is not working. I have
> this right now, in mpdv.core, which is the core namespace is an app I
> created with lein:
>
>
> (defn process-startup-hooks []
> "2013-02-21- remember, each row in hooks is a map: {:order-of-events 1,
> :event-name 'connect-to-database'}"
> (connect-to-database)
> (let [hooks (sort-by :order-of-events
> (:events-called-when-the-app-starts-hooks @um/interactions))]
> (doseq [x hooks]
> (let [event-as-symbol (symbol (:event-name x))
> event (ns-resolve *ns* event-as-symbol)]
> (println " what kind of var is this? ")
> (println *ns*)
> (println (type event-as-symbol))
> (println event-as-symbol)
> (if-not (nil? event)
> (event))
>
>
> "event" is always nil. One of the events listed in um/interactions is
> "connect-to-database" so, as a test, I hardcoded it here, to be sure it
> could run here, and it runs fine (first line after the comment). So the var
> for the function is known. But this:
>
> (ns-resolve *ns* event-as-symbol)
>
> returns nil, even when event-as-symbol is "connect-to-database".
>
> When I println *ns* to the terminal output, I see the namespace is:
>
> #
>
> Which surprises me somewhat.
>
> How do I get ns-resolve to look in mpdv.core for the var that I want it to
> find?
>
> --
> --
> 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)
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how do I reference a var that is in my core namespace?
I wanted to have some functions run when an app starts, and I wanted this
to be configurable, because I plan to use the same architecture for several
apps. So I thought I could have the function names as strings inside of
maps inside of a set (that I sort), in a config file. And I thought I could
use ns-resolve *ns* symbol to turn the strings into references to the vars
where the function definitions are stored. But somehow this is not working.
I have this right now, in mpdv.core, which is the core namespace is an app
I created with lein:
(defn process-startup-hooks []
"2013-02-21- remember, each row in hooks is a map: {:order-of-events 1,
:event-name 'connect-to-database'}"
(connect-to-database)
(let [hooks (sort-by :order-of-events
(:events-called-when-the-app-starts-hooks @um/interactions))]
(doseq [x hooks]
(let [event-as-symbol (symbol (:event-name x))
event (ns-resolve *ns* event-as-symbol)]
(println " what kind of var is this? ")
(println *ns*)
(println (type event-as-symbol))
(println event-as-symbol)
(if-not (nil? event)
(event))
"event" is always nil. One of the events listed in um/interactions is
"connect-to-database" so, as a test, I hardcoded it here, to be sure it
could run here, and it runs fine (first line after the comment). So the var
for the function is known. But this:
(ns-resolve *ns* event-as-symbol)
returns nil, even when event-as-symbol is "connect-to-database".
When I println *ns* to the terminal output, I see the namespace is:
#
Which surprises me somewhat.
How do I get ns-resolve to look in mpdv.core for the var that I want it to
find?
--
--
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Groups "Clojure" group.
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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
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