Notice it says "can't recur from within a catch". So throw the
try/catch into it's own function and return nil if the try fails. Then
throw a if statement to continue the loop only if the function return
nil.
Timothy
On Thu, Mar 17, 2011 at 8:49 PM, Fiel Cabral
<e4696wyoa63emq6w3250kiw60i4...@gmail.com> wrote:
> Hello Clojure users,
> This is a dumb question but I'd like to write something equivalent to this
> in Clojure:
>
> public String loop_with_exception(int retries)
> {
> for (int n = retries; n > 0; n--) {
> try {
> return some_io_operation();
> } catch (IOException e) {
> continue;
> }
> }
> return null;
> }
> So I tried writing it like this:
>
> (ns sandbox.core
> (:import [java.io.IOException]))
>
> (defn some-io-operation
> "Some read I/O operation that could throw an IOException."
> []
> (println "WOULD do a read operation"))
> (defn loop-with-exception [retries]
> (loop [n retries]
> (try
> (when (pos? n)
> (some-io-operation))
> (catch IOException e
> (recur (dec n))))))
>
> But I get this error:
> cd c:/EMACSHOME/CLOJURE-PROJECTS/sandbox/src/sandbox/
> 1 compiler notes:
> Unknown location:
> error: java.lang.UnsupportedOperationException: Cannot recur from
> catch/finally
> core.clj:13:9:
> error: java.lang.UnsupportedOperationException: Cannot recur from
> catch/finally (core.clj:13)
> Compilation failed.
> What's the recommended way to handle exceptions and retry inside a
> loop/recur?
> Thank you.
> -Fiel Cab.ral
>
> --
> 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
--
“One of the main causes of the fall of the Roman Empire was
that–lacking zero–they had no way to indicate successful termination
of their C programs.”
(Robert Firth)
--
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
