Re: problem with threading and sql lib
Nothing leaps out at me as a likely cause of a dropped message. - The only reason I can think of: It could be a problem when the loading of the JDBC driver is happening inside a thread. At least that would explain why calling (with-connection db nil ) before the thread is started, solves the problem. OTOH, the loop/recur at the end is probably better changed to a doseq. Thanks for this tip. Regards Roger --~--~-~--~~~---~--~~ 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: Metadata: something funny
Hmm, I also note that:
(def b #^{:b 2} (quote (1 2 3))) ; ^b - {:line 1}
(def b #^{:b 2} (list 1 2 3)) ; ^b - nil
On Sun, Sep 20, 2009 at 12:20 PM, samppi rbysam...@gmail.com wrote:
I was messing with the REPL when I found this happens:
Clojure 1.0.0-
user= (def a #^{:a 5} [1 2 3])
#'user/a
user= ^a
{:a 5}
user= (def b #^{:b 2} '(1 2 3))
#'user/b
user= ^b
{:line 3}
user= (def c (with-meta '(1 2 3) {:c 0}))
#'user/c
user= ^c
{:c 0}
What's going on with that {:line 3}? Is it something that the REPL is
doing? Where did {:b 2} go? And why does it happen with the reader
macro #^ and not with-meta?
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Re: Metadata: something funny
I just checked against the latest 1.1 snapshot. It
returns the same result as you outlined here.
On Sun, Sep 20, 2009 at 12:20 PM, samppi rbysam...@gmail.com wrote:
I was messing with the REPL when I found this happens:
Clojure 1.0.0-
user= (def a #^{:a 5} [1 2 3])
#'user/a
user= ^a
{:a 5}
user= (def b #^{:b 2} '(1 2 3))
#'user/b
user= ^b
{:line 3}
user= (def c (with-meta '(1 2 3) {:c 0}))
#'user/c
user= ^c
{:c 0}
What's going on with that {:line 3}? Is it something that the REPL is
doing? Where did {:b 2} go? And why does it happen with the reader
macro #^ and not with-meta?
--
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Re: Metadata: something funny
On Sun, Sep 20, 2009 at 6:20 PM, samppi rbysam...@gmail.com wrote:
I was messing with the REPL when I found this happens:
Clojure 1.0.0-
user= (def a #^{:a 5} [1 2 3])
#'user/a
user= ^a
{:a 5}
user= (def b #^{:b 2} '(1 2 3))
You have a quote symbol in there, so that line can also be written as:
(def b #^{:b 2} (quote (1 2 3)))
#'user/b
user= ^b
{:line 3}
user= (def c (with-meta '(1 2 3) {:c 0}))
#'user/c
user= ^c
{:c 0}
What's going on with that {:line 3}? Is it something that the REPL is
doing? Where did {:b 2} go? And why does it happen with the reader
macro #^ and not with-meta?
--
Venlig hilsen / Kind regards,
Christian Vest Hansen.
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Re: Metadata: something funny
On Sun, Sep 20, 2009 at 7:25 PM, Christian Vest Hansen
karmazi...@gmail.com wrote:
On Sun, Sep 20, 2009 at 6:20 PM, samppi rbysam...@gmail.com wrote:
I was messing with the REPL when I found this happens:
Clojure 1.0.0-
user= (def a #^{:a 5} [1 2 3])
#'user/a
user= ^a
{:a 5}
user= (def b #^{:b 2} '(1 2 3))
You have a quote symbol in there, so that line can also be written as:
(def b #^{:b 2} (quote (1 2 3)))
... and #^{} applies read-time to the following *form* rather than the
value they evaluate to, so that is why neither (list ...) nor (quote
...) work.
#'user/b
user= ^b
{:line 3}
user= (def c (with-meta '(1 2 3) {:c 0}))
#'user/c
user= ^c
{:c 0}
What's going on with that {:line 3}? Is it something that the REPL is
doing? Where did {:b 2} go? And why does it happen with the reader
macro #^ and not with-meta?
--
Venlig hilsen / Kind regards,
Christian Vest Hansen.
--
Venlig hilsen / Kind regards,
Christian Vest Hansen.
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Re: Silly Convention Question
I think this further reinforces the need for a clj-lint of sorts. I know I have accidentally declared variables, fns, etc. in both def- derivative forms and in let-style forms that have shadowed a var that was in use somewhere else higher up. It would be handy to have a tool I could run over my source that would highlight instances such as this and many other instances of non-idiomatic code. Just like any other lint program, you would probably end up ignoring the advice of the checker, but it's still nice to have it pointed out to you. On Sep 18, 2009, at 7:06 PM, Sean Devlin wrote: For what it's worth, I try to follow the convention Rich uses in core f - for a function pred - for a predicate coll - for a collection body - for macro bodys name - symbol definition params - bindings Just my $.02 Sean On Sep 18, 6:37 pm, CuppoJava patrickli_2...@hotmail.com wrote: John illustrates a common scenario in Clojure. Clojure's built-in functions are tersely and sensibly named. The problem is that there is indeed a finite number of terse and sensible names... which bites you when you need some of those names. Hence why in my code I have started to just capitalize variables. In my code: A function is something that is executed in its lexical scope. -Patrick --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
Q: How to convert a struct-map to xml and back (ignoring functions)?
I would like to encode/decode Clojure structures to/from a database. Parsing XML is easy, but I can't seem to find a simple way to encode Clojure structures to XML and back. Atm my structures are simple: just simple key/value pairs where the key is always a string and the value is always a string or a set of strings. clojure.xml/emit and clojure.contrib.laxy_xml/emit both require specially constructed structures which isn't useful to me. I was hoping for a core or contrib function that was more generic that dynamically and recursively determined the structure keys for element names and strings for the element text data. In my mind I was thinking something simple like what Sarissa provides for JavaScript. If nothing exists I'll take a stab at it. I just thought I'd ask because the available Clojure libraries seem quite good and I feel like I'm missing something obvious. Cheers. --~--~-~--~~~---~--~~ 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: If you wish to have a version for off-line use...
Personally, that's not what I want. I want to download the clojure.org web page - one level deep so the files api, special_forms, macros, etc. are all available on my laptop offline. I tried a couple of programs (wget and httrack) to get this but there is some strange combobulation of redirects and cookie sessions going on that prevented these from working (for me). If anyone knows an easy way to get this documentation available offline please contribute. --~--~-~--~~~---~--~~ 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: Q: How to convert a struct-map to xml and back (ignoring functions)?
I've found clojure-contrib/prxml to be very useful http://richhickey.github.com/clojure-contrib/prxml-api.html On Sep 21, 8:32 am, MarkSwanson mark.swanson...@gmail.com wrote: I would like to encode/decode Clojure structures to/from a database. Parsing XML is easy, but I can't seem to find a simple way to encode Clojure structures to XML and back. Atm my structures are simple: just simple key/value pairs where the key is always a string and the value is always a string or a set of strings. clojure.xml/emit and clojure.contrib.laxy_xml/emit both require specially constructed structures which isn't useful to me. I was hoping for a core or contrib function that was more generic that dynamically and recursively determined the structure keys for element names and strings for the element text data. In my mind I was thinking something simple like what Sarissa provides for JavaScript. If nothing exists I'll take a stab at it. I just thought I'd ask because the available Clojure libraries seem quite good and I feel like I'm missing something obvious. Cheers. --~--~-~--~~~---~--~~ 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: Metadata: something funny
That's perfect. Thanks a lot, everyone.
On Sep 20, 11:35 am, Jarkko Oranen chous...@gmail.com wrote:
(def b #^{:b 2} (quote (1 2 3)))
... and #^{} applies read-time to the following *form* rather than the
value they evaluate to, so that is why neither (list ...) nor (quote
...) work.
Yep. #^ is for read-time metadata. Note though that the following will
work:
(def b '#^{:b 2} (1 2 3)) ; read carefully :)
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Re: Can anyone here give a comparison between Clojure and Erlang on concurrent programming?
A million thanks to you guys! To ss: concise and clear. very helpful! To Wojtek: very detailed, I'll bear your suggestion in my mind! Thanks a lot To Timothy: thanks for sharing! -dongbo --~--~-~--~~~---~--~~ 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: If you wish to have a version for off-line use...
Generally I use the source code for clojure and contrib documentation. I open an instance of Jedit on the source directory and use it's search/grep facilities to find what I'm looking for. It also helps in familiarising with the clojure and contrib implementations and learning the techniques used. It's also always available. (I use vim/vimclojure separately as my ide and jedit only for source/doc browsing). Rgds, Adrian. On Mon, Sep 21, 2009 at 12:37 AM, MarkSwanson mark.swanson...@gmail.com wrote: Personally, that's not what I want. I want to download the clojure.org web page - one level deep so the files api, special_forms, macros, etc. are all available on my laptop offline. I tried a couple of programs (wget and httrack) to get this but there is some strange combobulation of redirects and cookie sessions going on that prevented these from working (for me). If anyone knows an easy way to get this documentation available offline please contribute. --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
exception: agents + swing
hi, i don't have a repro case yet, but i've been trying to use agents to be able to get swing's thread to draw things from my engine w/out having to think hard about threading; using @agent in my swing-related code to get the state of things to be drawn. but sometimes i get an error on a source line that is doing @agent. for example, below is the top of one such exception. any ideas what might be going on to case this exception? i'm on clojure 1.0.0, winxppro, java 1.6.0_15-b03. user= Exception in thread AWT-EventQueue-0 java.lang.Exception: Agent has errors at clojure.lang.Agent.deref(Agent.java:129) at clojure.core$deref__3725.invoke(core.clj:1285) thanks. --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
Q: how to solve this concurrency problem ?
Hi, im not sure how to solve the following problem: (defn parse [outstream-agent xml] (let [content (clojure.xml/parse (ByteArrayInputStream. (. xml getBytes))) first-element (:tag content) ] (try (if @*is-syncing* (do ; iust continue f the agent is not running (await *message-cache-agent* ) (if @*is-syncing* (let [command (first-element *process-during-sync*) cache (first-element *cache-during-sync*) ] (if command (command outstream-agent content) (if cache (cache-message content) ) ) ) ((first-element *messages*) outstream-agent content) ) ) ((first-element *messages*) outstream-agent content) ) (catch Exception e (do (info (. e getMessage)) (fatal (str Unknown command: first-element)) false ) The above code can be run by n threads. If the application is syncing certain messages are going to be cached. At some point the messages in the cache needed to be processed by a different thread (the *message- cache-agent* in this example). After that *is-syncing* is false. The problem with the above code is that messages could be added to the cache after the message-cache-agent is started so that is possible that some messages are not sent by the agent. Right now I can only think of two solutions: 1.) the message-cache-agent checks for a certain amount of time if there are now new messages 2.) I modify the code like this: (if cache (cache-message content) (if (mesage-cache-agent-is-running) (send-of *message-cache-agent* send-last-message-with content ) The question is.What would be the correct solution to this problem ? Regards Roger --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
