Re: Intern a var from outside namespace
I can see the potential problems with this pattern, but it also seems like a nice way to metaprogram things like controllers or models in a web app. (In non-web Clojure dev, I haven't ever run into this issue.) Will have to think about this some more... On Friday, October 12, 2012 at 11:33 AM, Stuart Sierra wrote: Sounds like a load-order issue. Make sure the code *creating* the namespaces/vars is loaded before the code *using* them. But better yet, just don't do it. :) -S -- 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 (mailto: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 (mailto: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 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
Re: Intern a var from outside namespace
On Friday, October 12, 2012 4:38:36 PM UTC+11, David Jacobs wrote: Having a map leads to pretty bad syntax for what I'm trying to do. That's why I want to metaprogram here. I want this ... (post/all api-key) … instead of this ... ((post/api :all) api-key) I'm not sure, but that second one looks pretty fine to me. It's also a lot more obvious where the function comes from. -- 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
Re: Intern a var from outside namespace
Sounds like a load-order issue. Make sure the code *creating* the namespaces/vars is loaded before the code *using* them. But better yet, just don't do it. :) -S -- 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
Intern a var from outside namespace
I would like to create function names programmatically. So far, I have code
that works:
(defn create [endpoints]
(doseq [{:keys [action method url]} endpoints]
(let [endpoint-fn (if (re-matches #.*/:id(/.*)? url)
(fn [id session]
(method (string/replace url #:id id) session))
(fn [session]
(method url session)))]
(intern *ns* (symbol action) endpoint-fn
This creates functions from an array of hashes of the form {:action index
:method api/get :url url}.
But I want to move this to a namespace where I can call it from multiple other
namespaces. As soon as I replace this function with the following, it stops
working:
(defn create [a-ns endpoints]
(doseq [{:keys [action method url]} endpoints]
(let [endpoint-fn (if (re-matches #.*/:id(/.*)? url)
(fn [id session]
(method (string/replace url #:id id) session))
(fn [session]
(method url session)))]
(intern a-ns (symbol action) endpoint-fn
;; From other ns:
(other-ns/create *ns* endpoints)
Where am I going wrong?
David
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Re: Intern a var from outside namespace
On Thursday, October 11, 2012 9:03:38 PM UTC-7, David Jacobs wrote: I would like to create function names programmatically. So far, I have code that works: ... Where am I going wrong? David Sentence one. Don't do it that way: namespaces are not very good hashmaps, but hashmaps are excellent at that. You already have the data that you need to make this handler, and there's no need to scatter it into dozens of functions: use that data to create a single function that does the dispatching logic that you need, and put that into your ring routes or whatever. -- 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
Re: Intern a var from outside namespace
Note: I wrote this quickly. I should've taken the time to point out that the
only difference between the first and second functions is the parameterized
namespace, a-ns. When I say it doesn't work, I mean that accessing the
created fn from a third ns throws a No such var exception.
On Thursday, October 11, 2012 at 9:03 PM, David Jacobs wrote:
I would like to create function names programmatically. So far, I have code
that works:
(defn create [endpoints]
(doseq [{:keys [action method url]} endpoints]
(let [endpoint-fn (if (re-matches #.*/:id(/.*)? url)
(fn [id session]
(method (string/replace url #:id id) session))
(fn [session]
(method url session)))]
(intern *ns* (symbol action) endpoint-fn
This creates functions from an array of hashes of the form {:action index
:method api/get :url url}.
But I want to move this to a namespace where I can call it from multiple
other namespaces. As soon as I replace this function with the following, it
stops working:
(defn create [a-ns endpoints]
(doseq [{:keys [action method url]} endpoints]
(let [endpoint-fn (if (re-matches #.*/:id(/.*)? url)
(fn [id session]
(method (string/replace url #:id id) session))
(fn [session]
(method url session)))]
(intern a-ns (symbol action) endpoint-fn
;; From other ns:
(other-ns/create *ns* endpoints)
Where am I going wrong?
David
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Re: Intern a var from outside namespace
Having a map leads to pretty bad syntax for what I'm trying to do. That's why I want to metaprogram here. I want this ... (post/all api-key) … instead of this ... ((post/api :all) api-key) Why can an ns not be passed around like anything else? David On Thursday, October 11, 2012 at 9:18 PM, Alan Malloy wrote: On Thursday, October 11, 2012 9:03:38 PM UTC-7, David Jacobs wrote: I would like to create function names programmatically. So far, I have code that works: ... Where am I going wrong? David Sentence one. Don't do it that way: namespaces are not very good hashmaps, but hashmaps are excellent at that. You already have the data that you need to make this handler, and there's no need to scatter it into dozens of functions: use that data to create a single function that does the dispatching logic that you need, and put that into your ring routes or whatever. -- 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 (mailto: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 (mailto: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 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
