#clojure – 2014-12-05

2014-12-05

00:44	timvishet	anyone using cider 0.8.1 and austin 0.1.5, after running (austin-exec) with the default phantomjs exec-env get WARNINGs for basically every public cljs.core entity?
00:45	timvishet	oh, and you have to try to M-x cider-load-file to trigger the WARNINGs
00:46	timvishet	seems to well and truly fubar the repl, i have to cider-restart each time
01:30	rritoch	What is the URL of the web history of this chatroom?
01:32	otti	clojure-log.n01se.net
01:33	rritoch	otti: Thanks :)
01:34	otti	hm how can i splitup tests with leiningen? because i wrote some helper functions for a few tests, put them into a file /tests/helpers.clj. and now i have all the other tests in separate files.
01:34	otti	but when i want to load them within core-test.clj there are problems with the namespaces, namely it can't find the namespace because it looks at /src/app/test-files.clj
01:34	justin_smith	otti: if you put the files in the classpath (ie. under the test/ directory) they can be required by the other files
01:35	otti	justin_smith: hm didn't work
01:35	justin_smith	otti: does the path to the file match the namespace in the file?
01:35	justin_smith	because it needs to
01:35	rritoch	otti: The only way I know of that you can split-up test is to use 'lein test :only test-namespace/some-test
01:36	justin_smith	otti for example if the file is in test/helpers.clj the namespace needs tobe called helpers
01:36	otti	justin_smith: it is
01:36	justin_smith	otti: then the other reason it wouldn't load is if there is an error in the file
01:37	otti	i only could solve it by linking the test directory within /src and use the following namespace scheme for the files: test.my-test-namespace.test-file
01:37	justin_smith	otti: that should not be needed at all. I use namespaces under test/ frequently with no issue
01:37	otti	but that sucks because on lein run the test files are considered too
01:37	otti	justin_smith: i try as you suggested again
01:38	justin_smith	lein run won't load or use files that are not required by your core namespace anyway, so that isn't even an issue
01:38	otti	but who do you explain the fact, that i once got an exception, while executing
01:39	justin_smith	and if the namespace is test.my-test-namespace.test-file than the path needs to be test/test/my_test_namespace/test_file.clj
01:39	otti	'lein run' within the tests
01:39	justin_smith	otti: something must have required or attempted to compile the file, but lein run wouldn't do that on its own
01:39	otti	hm
01:40	justin_smith	otti: perhaps you had :aot :all turned on?
01:40	otti	hm think, i just found the issue
01:40	otti	justin_smith: no
01:40	otti	justin_smith: it could be because i use vim-fireplace and run :Eval (core.test/run-tests)
01:41	otti	which is connected to the repl that probably then goes looking within /src/app/
01:41	otti	for the required files
01:41	otti	instead of /test/app/
01:41	justin_smith	clojure.test/run-tests does not load any files
01:41	justin_smith	it only runs the tests that you have defined / loaded previously
01:42	justin_smith	perhaps fireplace loaded the files? I don't know how fireplace does things. lein should only be looking for test namespaces under test/
01:43	otti	fireplace connects to the repl (lein repl) and, yes i have to load the files
01:43	otti	by calling :Require from within vim
01:50	otti	hm very strange
01:52	justin_smith	otti: you say "probably then goes looking within /src/app for the required files instead of /test/app/"
01:52	justin_smith	otti: the way the classpath works, files under src/ and files under test/ are considered the same location
01:53	justin_smith	so you can't count on src/app/foo.clj vs. test/app/foo.clj - they are both the same relative path
01:53	otti	justin_smith: i don't know probably i made some mistakes the first time that i started to write the tests
01:53	justin_smith	OK
01:53	otti	because i removed the link within /src to /test
01:54	otti	and changed the namespaces
01:54	otti	and no namespace exceptions
01:54	otti	thus it works now
01:54	otti	justin_smith: thanks for the clearance
01:56	justin_smith	np
02:08	rritoch	I found another variation of classloader initiated incompatibility during compilation. I am unsure if this is related to yesterday's issue or not. http://pastebin.com/ydcQ9fVc
02:09	justin_smith	rritoch: Bronsa came up with a fix for that issue today BTW
02:10	rritoch	Cool, I haven't had a chance to check all of the logs
02:10	rritoch	Does it resolve this issue also?
02:11	justin_smith	I think it should. But I'm not sure of that.
02:12	rritoch	justin_smith: Do you have a link to the solution? Bronsa was very active
02:13	rritoch	Hmm,maybe I found it
02:14	rritoch	Is this patch supposed to fix it? http://sprunge.us/YddP?diff
02:14	justin_smith	yeah, that's the one
02:16	rritoch	Interesting that he decided to go with the baseLoader. I suppose that is a good idea because the way it is currently you don't have any control over what classloader gets used
02:16	rritoch	I was thinking that it would be better to check interned classes first though
02:18	rritoch	Such as adding a map from the fully qualified classname, to the class for any class that gets interned, and checking against that whenever the fully qualified classname is used to ensure consistancy of classes within namespaces.
02:19	rritoch	I don't think this patch fixes this new issue though, I'll have to double check something in the compiler to see.
02:23	rritoch	Ok, yes, this should fix the case I found also. The case in this pastebin shortcuts to RT.classForName which was just resolving to Class/forName before this patch. So it looks like the patch resolves both issues.
02:23	rritoch	I still think it would be more stable though to check against interned classes first
02:25	rritoch	This additonal control over which classloader is used will certainly help, but could make some systems less stable if library developers start abusing the feature.
02:29	rritoch	Either way, this problem was very helpful in learning how clojure classloading works. At least now I don't have to ignore the stacktrace portions that start with compiler, since I know what they're doing now :)
02:32	kenrestivo	rritoch: they were talking about how they'd put the fix in jira and, if you want it, you might want to vote it up.
02:33	kenrestivo	i don't remember the ticket number but it's in the logs
02:35	rritoch	Sure, I'll vote-up anything that gives more control to the developer. I tried a lot of different tricks trying to get control over which classloader would be used and there really was no way around that Class.forName code
02:36	rritoch	I'm still a bit curious though what the real cause of yesterdays issue was though, as far as I can tell the only thing that could have caused it is if the non-fully qualified name is getting resolved to a qualified name at some point, but short of adding debugging notices to the compiler I couldn't tell.
02:37	rritoch	Looking at the code example, any non-qualified name checks interned classes so I'm not sure how the example was bypassing the interned class
02:38	rritoch	Changing the interned class would alter which class was used at the top level, but not within the let
02:39	rritoch	I even started using let* for my tests to ensure there was no "funny-business" going on within the macro that was applying the clojure.core namespace during macro expansion.
02:40	rritoch	I just couldn't figure out a test, short of adding debugging messages to the Compiler, to see if the symbol was getting resolved to the fully qualified name within the let* statement.
02:42	rritoch	It would be nice if the compiler had a debug-compile setting so we could see the internal processes without needing to hack the compiler
02:46	rritoch	Would the &env in a macro show if a symbol in a let* has been resolved to a fully qualifed name?
02:47	rritoch	Or would it just show the final eval'd value
03:14	epichero_	i need to spend a few hours getting cider setup with autocomplete setup with my customized emacs using evil mode and hooks...
03:15	sm0ke	is there something like try-let ?
03:16	sm0ke	where the let binding are available in the finally clause
03:16	opqdonut	sm0ke: just have try inside let?
03:17	opqdonut	that's how e.g. with-open is defined IIRC
03:17	opqdonut	yep: https://github.com/clojure/clojure/blob/clojure-1.6.0/src/clj/clojure/core.clj#L3512
03:17	Empperi	rritoch: I used to use ccw
03:17	Empperi	these days I use IntelliJ + Cursive
03:19	sm0ke	rritoch: what if the binding cause exception/
03:19	sm0ke	sorry ^ opqdonut
03:19	rritoch	Empperi: Heh, I just had to install IntelliJ today. I stick with counterclockwise because I program in a lot of different languages, and eclipse has good support for nearly every language I code in, accept possibly C#
03:19	Empperi	well, IntelliJ has support for as wide variety of languages
03:19	Empperi	maybe even wider
03:20	Empperi	I personally do clojure, java, javascript, dart, bit of ruby, bit of python
03:20	Empperi	and of course html, css, markdown etc
03:20	rritoch	Empperi: ccw is fairly broken, but anything I can't do from eclipse I can do from a shell, or PSPad, so I'm able to deal with it.
03:21	Empperi	yeah, ccw isn't that bad really
03:21	Empperi	it's the eclipse I had problems with
03:21	Empperi	used it for maybe 10 years
03:21	mavbozo	long live clojure!!! http://matthiasnehlsen.com/blog/2014/12/04/Farewell-Scala/
03:21	opqdonut	sm0ke: with-open with multiple bindings desugars into a nested try-let-try-let...
03:21	opqdonut	sm0ke: so if e.g. the third binding fails, the first two get freed
03:21	opqdonut	s/freed/closed/
03:23	andyf	rritoch: Sometimes adding debug print?s to the Clojure compiler is the quickest way to find out what you want.
03:27	rritoch	andyf: Well, I'm about to start playing with that code soon, but I don't see any "installation" instructions. Once I get it compiled with ant, how do I install it into the localrepo?
03:28	andyf	rritoch: mvn install
03:28	andyf	There may be other ways, but that should do it.
03:28	rritoch	andyf: ty, that sounds easy enough
03:32	andyf	If you want to skip running the tests: mvn -Dmaven.test.skip=true
03:32	andyf	I mean: mvn -Dmaven.test.skip=true install
03:33	andyf	That particular command is not on this web page, but the -Dmaven.test.skip=true part is: http://dev.clojure.org/display/community/Developing+Patches
03:34	rritoch	andyf: Thanks, I made a note of it. I don't think I'll have time to start tinkering until monday though
03:36	rritoch	andyf: My primary goal is to create encapsulated namespaces to make it possible to have separate virtual runtimes (sandboxes?) within clojure, so OSGi modules can have a safe environment free of namespace and version conflicts.
03:37	rritoch	andyf: It won't support multiple versions of clojure itself, but it could support independent versions of anything else.
03:37	andyf	I don't know if I would ever need such a thing, but sounds worth learning about some time. I have briefly wondered about ways to avoid problems with conflicting library dependencies in Clojure programs.
03:38	andyf	The most common solution is to modify dependencies until only a single version of each library is in use.
03:38	andyf	but that can be difficult, and in some cases impossible.
03:39	rritoch	andyf: Well I've found two methods that people are using. One is creating a custom namespace, and the other is to use a clojure "shim" library.
03:39	rritoch	err, creating a custom classloader
03:39	rritoch	Both methods involve toying with java classloaders, which is a guaranteed way to run into troubles
03:40	andyf	I've been developing a Clojure lint tool called Eastwood, which evaluates the Clojure code it is analyzing, and to avoid library conflicts between that program and what Eastwood itself uses, I've copied libraries into Eastwood, and renamed their namespaces to something that other programs don't use.
03:40	andyf	crude, but effective
03:43	rritoch	Well, that sounds like it would work in most cases
03:47	rritoch	In my apps I'm using OSGi which already provides isolation for java classes within a module, but getting that isolation to clojure is inefficient. Modules would either need to include their own runtime, which ads a significant overhead to the load time, or classloading "magic" needs to be done to isolate the runtime. I intend to change namespace handling so the namespace registration ...
03:47	rritoch	clojure.lang.Namespace/namespaces gets stored in thread-local memory, making it possible to isolate environments
03:57	rritoch	Thinking more about the issue though, as it relates to OSGi integration, any version with namespace isolation support could be shared, so this would support multiple versions of clojure, but would only need one runtime per version, so multiple modules depending on the same clojure version could share a single runtime.
03:57	rritoch	At least that's the goal.
03:58	rritoch	I certainly could end up with an environment that is completely unstable and unusable
03:58	andyf	Out of curiosity, do you have an application that needs this?
03:59	rritoch	Yes, I'm developing a web platform/framework which needs it
04:00	rritoch	https://github.com/search?q=user%3Arritoch+clj-grid
04:02	rritoch	The system uses a MVC design pattern, that is now namespace based instead of class based, and provides jsp support for templates that are easy to manage by web designers
04:03	rritoch	I also have "dreams" of eventually support libGDX as a OSGi module, but I haven't even attempted that yet. I still have a lot of core issues to deal with.
04:04	andyf	So the web framework will not achieve its goals without OSGi support?
04:06	rritoch	andyf: The OSGi support is to provide plugins, and facilitate commercial interest in the platform.
04:07	rritoch	andyf: Businesses aren't going to be very interested in developing plugins that can only be delivered via maven (open source), by giving the download and install option it opens up commercial interests.
04:10	andyf	Aren't there closed source Java libraries delivered via jar files?
04:13	rritoch	andyf: Yes, but OSGi provides module isolation, so you don't end up with as many plugin conflicts, such as are faced by wordpress
04:13	borkdude	does anyone still use lein cucumber? https://github.com/nilswloka/lein-cucumber
04:15	cfleming	rritoch: I'd be very interested to hear about what you come up with.
04:15	cfleming	rritoch: I'm no longer using OSGi, but I have a similar problem with IntelliJ plugins.
04:15	cfleming	rritoch: i.e. I'd like to be able to load Clojure code into plugins without replicating the Clojure runtime across each of them.
04:16	rritoch	andyf: I believe openbravo provides modular support without OSGi, but for the most part OSGi is becoming an industry standard which is why I decided on OSGi as the basis for modularity.
04:18	rritoch	andyf: To provide JSP support I'm already locked into the apache license anyhow, ...
04:19	rritoch	When given the choice between anything and jboss, I'll choose anything, after JBoss's greedy patent lawsuits when their patents should have been completely invalid since day one since they patented a common software development practice, of having database fields mapped to object fields.
04:19	rritoch	Because of those lawsuits I will do whatever it takes to avoid using ANY JBoss product
04:20	rritoch	I also don't include any ORM support in my apps to ensure that JBoss can't get their greedy hands on any of my work
04:21	shiranaihito	rritoch: i always just figured JBoss was way too "Enterprisey", but i guess they're full of shit too
04:24	lxsameer	hey folks, is ther any solution to build android apps using clojure /
04:24	rritoch	Well, I've watched that situation closely because it is a huge thorn in the side of web development, that most web developers aren't aware of
04:24	shiranaihito	rritoch: plenty of other app servers around, though?
04:24	rritoch	Recent supreme court decisions seem to have invalidated JBoss's patent on ORM design, and most software patents, but there hasn't yet been a case to test that theory.
04:25	rritoch	shiranaihito: There aren't many that I can find that are stable and well maintained, other than Apache Tomcat
04:25	shiranaihito	i'm not sure that matters.. court decisions will always favour the wealthy and politically connected anyway
04:25	shiranaihito	Jetty?
04:27	rritoch	shiranaihito: I've started running into jetty a lot lately, and haven't tried it yet. I didn't find jetty until after I was already locked into tomcat libraries.
04:28	shiranaihito	rritoch: afaik, Jetty is very good.. i don't have experience running it in a Serious environment though, so that this for what it's worth
04:28	shiranaihito	i'm basing my own Clojure web app development on top of Jetty though
04:30	shiranaihito	rritoch: one considerable advantage that Jetty has is that you can embed it in a stand-alone Java/Clojure application
04:30	shiranaihito	"so that this for what it's worth" <-- _take_ this for what it's worth, even..
04:31	rritoch	shiranaihito: Tomcat can also
04:32	shiranaihito	alright, i guess that's new
04:32	rritoch	shiranaihito: Currently I'm depending on [org.apache.tomcat/tomcat-jasper "7.0.52"] which provides me all of tomcat
04:32	shiranaihito	wasn't Jasper the JSP engine.. ?
04:33	cfleming	borkdude: I've received at least one request to support it in Cursive, so someone is: https://github.com/cursiveclojure/cursive/issues/478
04:33	borkdude	cfleming ah ok. It doesn't work anymore on my machine, but I think it's because Firefox updated itself
04:34	cfleming	borkdude: Ok - I've never used it myself.
04:34	rritoch	shiranaihito: Yes, as much as possible I am avoiding accessing anything in the catalina namespaces though. Tomcat uses layers and layers of wrapperrs and containers so to keep things light-weight I've been making my own servlet contexts and servlet config's to avoid the overhead
04:35	rritoch	shiranaihito: As of now, deployment to tomcat servers is fairly seamless since I'm using the same libraries, but other than running JSP's from the command line I haven't yet made a stand-alone server with it
04:35	shiranaihito	rritoch: hmm.. i don't quite follow
04:36	gavilancomun	There can be slight differences in interpretation of the Servlet 3 spec between Tomcat and Jetty, but they can be worked around
04:36	rritoch	shiranaihito: Catalina code in the tomcat library is what provides the servletconfig's and servletcontext's required by the JSP specification
04:36	shiranaihito	how do you "run JSP from the command line"?
04:36	shiranaihito	do you mean the Servlet specification? :P
04:36	rritoch	yeah :)
04:37	shiranaihito	:P
04:37	shiranaihito	but still, "running JSP" from the command line (or anywhere for that matter) sounds weird
04:37	rritoch	The code to run jsp from the command line is all in http://www.github.com/rritoch/clj-grid-core , it wasn't easy
04:38	rritoch	shiranaihito: Well, the intention behind that is to eventually provide CGI capability
04:38	gavilancomun	The two issue I have had are scanning jars for annotations alongside web_fragment.xml files...
04:39	rritoch	shiranaihito: Running via CGI would be slow, and cause the loss of all persistence benefits, but it is good for testing
04:39	rritoch	shiranaihito: Currently I only use the command line support for testing/debugging
04:39	gavilancomun	and how the notion of current URL changes it calls to redirect() and calls to .forward() with a relative URL.
04:40	gavilancomun	it -> with
04:40	shiranaihito	rritoch: but "CGI" is what Servlets replace, right? it's just an interface for running code that's "called" by a server over the Internet?
04:40	shiranaihito	dflkjdsfdf
04:41	shiranaihito	rritoch: "called" by a browser, that is
04:41	shiranaihito	sorry.. i'm in a brainfarty mood, apparently
04:41	shiranaihito	JSP (Java Server Pages) is just a View layer for Servlet -based web applications, right?
04:43	rritoch	shiranaihito: JSP compiles to a servlet so it can provide the entire application, but typically a lot of back-end java is used
04:45	rritoch	shiranaihito: Either way, I'm only using it for a view layer to JSP web applications
04:45	shiranaihito	rritoch: yeah i know, but people don't write JSP for that aspect
04:45	rritoch	err, clj web applications
04:45	shiranaihito	:p
04:46	shiranaihito	rritoch: but yeah.. CGI.. i'm not even sure what you mean with that.. it used to be something like, a way to hand off a HTTP request to a separate process (one per request?), right?
04:47	shiranaihito	but why would you not use just plain Servlets or something on top of that instead?
04:48	rritoch	shiranaihito: Running it via CGI means there's no need for an application server. CGI are just command line applications, delivery of metadata occurs by environment variables, and content (for post/put/etc.) delivered on stdin
04:49	shiranaihito	rritoch: yes, but why do it like that, instead of using Servlets or some other established, non-ancient standard for accomplishing the same (and more)?
04:49	rritoch	shiranaihito: This way I can test features directly from the command line without needing to deploy an application server
04:50	rritoch	shiranaihito: Testing as CGI requires one command "lein run", no need to launch a server, install updates, or open a web browser
04:50	shiranaihito	rritoch: ok, but you could use a http client too.. which would be a better fit with making a web app, since it's going to be used over http anyway
04:51	shiranaihito	wouldn't "lein run" launch a web server too, typically? :p
04:52	rritoch	shiranaihito: Not with this platform, with this system lein run deploys a virtual web request, though I haven't added stdin reading or environment variable reading yet, so it isn't yet CGI compliant.
04:52	rritoch	shiranaihito: At some point I'll add something like 'lein grid server' to launch a stand-alone web server, and it's on my todolist
04:52	shiranaihito	rritoch: "virtual web request"? .. so you're doing "web-like" stuff to avoid doing actual web stuff? :p
04:53	rritoch	But first I need to deal with this isolation issue
04:53	rritoch	shiranaihito: Yes, development has been much faster that way
04:55	shiranaihito	rritoch: i'm still confused by what you're doing, and why, but.. i guess that's alright :P
04:55	shiranaihito	carry on! :P
05:05	rritoch	shiranaihito: The WHY is a big question I'm having a difficult time with lately, there isn't really any interest in this project outside my own mind, but I hope to be able to build enterprise class web applications in clojure that are easily maintained with a large team of developers
05:06	rritoch	shiranaihito: Your jetty project is the only other project I've heard of that has JSP support in clojure
05:06	Empperi	wait, what, why?
05:06	Empperi	jsp in clojure?
05:06	Empperi	man
05:07	shiranaihito	rritoch: if your goal is to write easily maintained web apps in Clojure, i don't see how "CGI-through-JSP-somehow" is the means towards that
05:07	shiranaihito	you could check out ring-jetty for some inspiration?
05:08	shiranaihito	it sets up a stand-alone Jetty instance and gives it a custom (Jetty-specific) request handler thingy, that calls ring handlers
05:08	rritoch	shiranaihito: ring is a deadzone for my application because ring rejects tomcat dependencies
05:08	shiranaihito	i think that's pretty straightforward, and i'm using parts of that for my own cute little web framework
05:08	shiranaihito	rejects?
05:09	rritoch	Yes, rejects, removes the dependency because it contains a servlet implementation
05:10	shiranaihito	rritoch: you mean there's some kind of dependency conflict with Lein?
05:10	shiranaihito	can you use the "exclude" command to work around it?
05:10	rritoch	No, I mean the ring plugin specifically rejects the dependency
05:11	Empperi	I know for a fact that several people are running clojure + ring apps on top of tomcat
05:11	rritoch	shiranaihito: I don't think so, exclude works at the package level, not the class level
05:11	rritoch	Empperi: Yes, they do that with the uberwar
05:11	Empperi	even if that is not the recommended way to do it
05:11	Empperi	yes, which is the right way to do it anyway
05:12	Empperi	the whole concept of using jars from tomcat's lib directory is just dumb
05:12	Empperi	imho
05:12	Empperi	makes deployments so much harder and gains nothing
05:13	Empperi	since one should run only one app per tomcat anyway so that when you need to restart tomcat because of one app you don't have to put other apps down too
05:13	Empperi	and only "gain" you could gain with tomcat lib directory based jar packages is the situation where you have same dependencies for multiple apps
05:14	ordnungswidrig	Empperi: containers should hide all the libs they use to the deployed apps
05:14	Empperi	and even if you do run several apps on top of same tomcat instance (which I don't recommend) then only thing you'll lose if you encapsulate that jar to each war is some disc space
05:15	Empperi	ordnungswidrig: yes, indeed. App decides what libraries they need, not the container
05:15	ordnungswidrig	Empperi: we know all the fun with log4j and jbos
05:15	Empperi	and that's my point, there is absolutely no reasonable reason to put jar packages into tomcat lib directory for your app
05:15	rritoch	shiranaihito: I don't know if they've changed the issue, but the exclusion code is @ https://github.com/weavejester/lein-ring/blob/0c9dff39929a8be35a04f2afc8580ab6b0e1d2d2/src/leiningen/ring/uberwar.clj#L26-L33
05:15	Empperi	it's an antipattern and the world is better without it
05:17	Empperi	if it is a problem for your server that you might have even few megabytes more of data on it's disc then you have a completely different problem altogether
05:17	maxpn	how to implement javascript-like setTimeout() in Clojure?
05:17	rritoch	shiranaihito: I attempted to use ring, but it was skipping my tomcat dependency because it contains a servlet so I wasn't able to get jsp support with tomcat+ring
05:17	ordnungswidrig	Empperi: there are still links or file systems that do deduplication for that
05:17	ordnungswidrig	maxmartin: there's a lib called atat
05:17	rritoch	shiranaihito: If I was aware of jetty+ring at the time the project may have gone in a different direction
05:17	godd2	maxpn you sure you dont just want sleep?
05:18	ordnungswidrig	rritoch: I never heard someone wanting jsp support in a ring app :)
05:18	maxpn	godd2: yes, sleep but not in main thred
05:18	godd2	maxpn you can just put it in a future
05:18	ordnungswidrig	maxmartin: (future (Thread/sleep 1000) (prn "foo"))
05:19	shiranaihito	rritoch: i can't tell what happened.. but that's ok.. did you have servlet.jar in your tomcat's global lib folder or something btw? that might cause a conflict
05:19	ordnungswidrig	&(future (Thread/sleep 1000) (prn "foo"))
05:19	lazybot	java.lang.SecurityException: You tripped the alarm! future-call is bad!
05:19	ordnungswidrig	lzybot: I'm sorry
05:19	maxpn	godd2: thank you, that is it!
05:19	maxpn	thank you all
05:20	rritoch	ordnungswidrig: Typical web designers simply won't be able to use clojure directly. JSP templates can be made which are 99% HTML, and typically web designers will just copy/paste in the JSP codes they need.
05:21	ordnungswidrig	rritoch: To my experience they prefer more something like mustache
05:21	rritoch	ordnungswidrig: JSP support in web apps is purely to facilitate employing web designers onto the projects.
05:23	rritoch	ordnungswidrig: I'm talking about professional web designers, not programmers experimenting with web design.
05:23	ordnungswidrig	rritoch: I know what you mean, it's just contrary to my experience with professional web designers.
05:24	ordnungswidrig	rritoch: I guess the preferences of web designers in this regard vary a lot over different communitites
05:25	rritoch	ordnungswidrig: Well, most web designers I've dealt with require templates to be as close to pure html as possible
05:28	ordnungswidrig	rritoch: sure. To my experience they prefer mustache, freemarker, velocity or like that. All those, like JSP, use html with some extra syntax sprinkled over the tags. As a developer I try to avoid JSP because that binds you to a servlet container and those scary compilcated JSP engines.
05:30	rritoch	ordnungswidrig: Well, the advantage of the platform I'm building is that it really can support any templating engine that's java based, including jsp
05:31	rritoch	ordnungswidrig: I'm dealing with all of the complexity within the platform itself
05:31	ordnungswidrig	rritoch: ok, that's a point.
05:31	ordnungswidrig	rritoch: good luck to you :-P
05:31	bja	/.er in me says JSP isn't an advantage
05:31	rritoch	ordnungswidrig: If clojure outputs directly to stdout (println) I have that bound to the servlets output stream, that opens a lot of possiblities
05:32	rritoch	ordnungswidrig: But in all of my example apps I'm jut forwarding to jsp's
05:32	rritoch	ordnungswidrig: I also recently made a .clj specific servlet, so you can even forward to a .clj script
05:40	kras	which is better in terms of performance #(nth % (- (count %) 1)) or #(first (reverse %)) ?
05:40	kras	for taking the last item
05:43	algernon	I'd think (last %) would be, if I may offer a third choice.
05:43	kras	4clojure problem #19, restriction on last :-)
05:44	rritoch	kras: For a large list the first would be faster because reverse isn't lazy, I believe rseq would be the fastest ##(time (first (rseq (range 10000))))
05:44	lazybot	java.lang.ClassCastException: clojure.lang.LazySeq cannot be cast to clojure.lang.Reversible
05:44	shiranaihito	rritoch: as someone pointed out, you can just use a templating engine like Velocity or FreeMarker
05:44	dgellow	hi #clojure
05:44	shiranaihito	there's no need for JSP.. if you're writing a web app, you'll just be spewing out HTML anyway, regardless of how you generate it
05:45	daniel```	hi dgellow
05:45	rritoch	Eek, didn't know lazy sequences aren't reversable :(
05:46	rritoch	shiranaihito: Most of my web designers know JSP, and there is a large market of JSP template designers
05:47	shiranaihito	rritoch: JSP is alright as a templating engine - i think its best feature is custom tags that can be nested, that enables a lot of modularity
05:47	dgellow	Is cemerick/Friend the de facto library for everything about authentication ? Or do you know other lib with a similar purpose ?
05:48	shiranaihito	but similar things can be achieved with Velocity or FreeMarker.. i'm not sure it warrants the complexity of the JSP setup etc
05:48	algernon	kras: ah :)
05:49	rritoch	shiranaihito: Ex. on odesk there are 920 velocity developers, but over 16,000 JSP developers
05:50	shiranaihito	rritoch: sure, but you're just producing HTML.. learning Velocity or FreeMarker is not difficult either - they're all templates for producing HTML anyway
05:50	shiranaihito	but i guess the biggest mystery to me is that CGI stuff
05:53	shiranaihito	it sounded like in a way, you'd be testing whether your actual app code can be called (from the command line)
05:54	shiranaihito	but that wouldn't really be a problem, right? .. it would be more useful to test the app's code itself, and you don't need to involve HTTP/CGI for most of that
05:54	rritoch	Anyhow, I need to get back to work, but adding jetty support seems reasonable. Eventually I want to swap out all of the tomcat dependent code into it's own library, but that's just one of MANY core issues that I need to deal with. The urgent one is namespace isolation for modules.
05:55	shiranaihito	(for example, most of your functions probably don't have to take a HttpServletRequest as a parameter)
05:56	shiranaihito	rritoch: don't strive for excessive generality either :) .. whatever that might happen to mean in practice
05:56	rritoch	shiranaihito: None do, I dynamically bind a servlet-request variable from the servlet, so every function has access to the request automatically
05:57	shiranaihito	rritoch: alright, but again, what would you need some kind of CGI contraption for? :)
05:57	daniel```	dgellow: it is, yes
05:57	daniel```	dgellow: i have looked for others, its by far the most used
05:57	kras	any suggestions on whom to follow on 4clojure, for learning from their solutions
05:57	shiranaihito	rritoch: besides, that doesn't sound very functional
05:57	rritoch	shiranaihito: As I said, it reduces development time for these core systems because it doesn't require the overhead of a server
05:58	rritoch	shiranaihito: The goal is to provide functions for access to the request
05:58	shiranaihito	rritoch: well what's the problem with running a server?
05:58	shiranaihito	functions that would access the global request variable?
05:59	rritoch	shiranaihito: Time, it takes 1 second to type lein run and get the results, up to a minute to restart a tomcat server
05:59	rritoch	shiranaihito: Previously I also had to install updates to tomcat, similar to the ring uberwar process
06:00	shiranaihito	rritoch: it takes.. let's say 1 second (to mirror your estimate :p) to start up a stand-alone embedded Jetty server :p
06:00	rritoch	shiranaihito: But I've bound the classloader to the development source paths now so I can develop the web apps now in real time, I only use the CGI mode for debugging core features
06:01	rritoch	shiranaihito: Ok, well the other advantage of CGI mode is that it will work on nearly every web server
06:01	rritoch	Anyhow, here is an example of how this servlet-request design gets converted into functional syntax. https://github.com/rritoch/clj-grid-mvc/blob/master/src/com/vnetpublishing/clj/grid/mvc/base/controller.clj#L49-L54
06:01	shiranaihito	rritoch: well, your app server will just take in http connections anyway right?
06:02	shiranaihito	so it doesn't really matter if it's tomcat or jetty or jboss etc
06:02	shiranaihito	"nearly any web server" will be able to proxy connections to your app server
06:02	christiaanb	Hi, I'm helping in organising the annual dutch functional programming day (http://wwwhome.cs.utwente.nl/~jankuper/fp-dag/), and I was wondering what the best way is to notify the members of your community of this event?
06:04	rritoch	hmm, just noticed I need to repair that function. Anyhow, I need to get back to work, but those "action"'s need to be changed with name, I was testing actions in controllers and must have been half-asleep when I coded it.
06:09	TEttinger	christiaanb, there is the clojure mailing list, which seems appropriate
06:09	rritoch	shiranaihito: As of now this doesn't have a stand alone application server, it is running via CGI mode or tomcat. I intend to use http-kit to provide a stand alone server, but I first need to deal with namespace isolation.
06:10	christiaanb	TEttinger: thanks
06:11	TEttinger	christiaanb, might be worth reaching out to any companies in the netherlands doing clojure dev, I don't know how you would get a list...
06:12	christiaanb	TEttinger: I think I'll try the user groups for that
06:12	dgellow	daniel```: thanks
07:17	triss	I'm always saying (vec (repeat n some-value))
07:18	triss	is that the easiest way of filling a vector with a default value?
07:18	Bronsa	that's the best way
07:19	triss	cheers Bronsa.
07:21	bja	boo: (read-string (pr-str (keyword "")))
07:22	bja	actually boo my logic that allows me to try to keyword ""
07:49	TimMc	bja: boo to code that keywords arbitrary strings as opposed to statically known values.
07:50	bja	well, they're not supposed to be arbitrary
07:51	bja	there was a bug that resulted in something along the lines of (keyword (string/join [" " "foo"])) to occur
08:06	mavbozo	will clojure eXchange 2014 London videos made available in youtube?
08:16	scottj	mavbozo: weren't previous ones available on skillsmatter.com only using vimeo but not accessible on vimeo's site?
08:17	mavbozo	scottj: oh, those videos are in skillsmatter.com. thanks scottj.
08:17	mavbozo	(inc scottj)
08:17	lazybot	⇒ 2
09:08	triss	hey all. so I'm writing my first proper app in clojure.
09:08	triss	I want to do the frontend in clojurescript
09:08	triss	what's the simplest way of adding clojurescript as a dependancy?
09:09	triss	is iyt possible to use lein to add it to an existing project or do i have to manually edit the project.clj?
09:57	sveri	triss: what I usually do is take a template and work on from there
09:58	sveri	triss: adding things later is a bit different, for this I generate a template (for instance with lein new chestnut tempname) and copy & paste the relevant pieces to my existing app
10:01	triss	thanks sveri....
10:01	triss	so create a new cljs project and copy the missing deps from there.
10:02	sveri	triss: this is a tedious thing to do, but usually only a one time setup, so I just do it
10:14	mnngfltg	Hey. Does anyone mock out dependencies like writing to the database? I've tried `conjure` with clojure.test and found it cumbersome.
10:28	bja	mnngfltg: mostly no. I write functions that return data and test the functions
10:29	bja	I mostly assume that the libraries I use to connect to external sources work
10:29	bja	those libraries have their own tests
10:29	mnngfltg	bja, right
10:29	mnngfltg	bja, but what about glue code, e.g. code with side-effecets that, say, writes to the database
10:30	bja	mnngfltg: code doesn't do that typically. It does something, and then finally writes to the db
10:30	bja	I can test the transforms I do
10:30	mnngfltg	bja, in my experience that's not always easy to do
10:31	bja	maybe not easy, but I try very hard to make that part of my design
10:31	bja	helps me live a much happier life
10:31	mnngfltg	I would be happier too :)
10:31	bja	the places I talk to the external world now are mostly over core.async channels
10:31	bja	and those are trivial to mock out when I need to
10:32	bja	i.e. in some logic that handles various failure modes
10:32	mnngfltg	interesting
10:32	mnngfltg	so having a queue helps you decouple the code from the actual side effects
10:33	bja	I mean, writing to or reading from a channel is a side effect, but I can usually isolate the actual writing to a db from the control logic that operates on channels
10:33	csd_	What do I need to do to a key-value object to treat it as if it were a JSON object?
10:33	bja	then I can test the control logic by creating various plain old channels and putting input on them or getting a value from them
10:33	bja	and my transforms can be mostly pure
10:34	bja	that's probably some sort of pattern with a name, but I couldn't tell you which one
10:35	mnngfltg	bja, it's an interesting approach, though maybe a bit too heavy if I don't have a use for core.async otherwise
10:36	mnngfltg	csd_, what do you mean by "treat as a JSON object"?
10:36	mnngfltg	csd_, generate a JSON string? (see cheshire or clojure/data.json
10:38	EvanR	,(:a {:a 1})
10:38	clojurebot	1
10:38	EvanR	,(2 {2 1})
10:38	clojurebot	#<ClassCastException java.lang.ClassCastException: java.lang.Long cannot be cast to clojure.lang.IFn>
10:38	EvanR	,({2 1} 2)
10:38	clojurebot	1
10:38	justin_smith	,(ifn? :a)
10:38	clojurebot	true
10:38	justin_smith	,(ifn? 2)
10:38	clojurebot	false
10:38	justin_smith	,(ifn? {})
10:38	clojurebot	true
10:38	csd_	mnngfltg: the chrome.storage api returns data in key/value pairs. dyntable wants JSON. i'm having trouble passing the object returned by the chrome api into dynatable, so I'm guessing it's because it's in some incorrect object format
10:39	EvanR	is it possible implement ifn in clojure
10:39	csd_	oh shoot i thought this was #javascript
10:39	EvanR	for newtypes
10:39	mnngfltg	csd_, JSON.stringify() ? :)
10:39	bja	#(.stringify js/JSON %)
10:39	justin_smith	EvanR: absolutely. Anything made with defrecord does it they way {} does by default.
10:40	justin_smith	EvanR: but you can get creative with it easily with deftype
10:40	EvanR	i keep getting confused about what can/cant implement protocols/interfaces
10:41	justin_smith	ifn? tests for clojure.lang.IFn
10:41	EvanR	which is an interface or protocol
10:42	justin_smith	I think it's an interface. Reagardless, protocol is just a very thin abstraction on interface.
10:42	justin_smith	and every protocol has an underlying interface that gets created
10:43	EvanR	java classes can have protocol impls
10:43	EvanR	but not interfaces?
10:43	justin_smith	java classes can easily have interfaces. It's a bit more work for them to integrate with protocols. nothing stops them from having both.
10:44	EvanR	alright
10:44	justin_smith	interfaces are part of the jvm. protocols are a clojure thing
10:44	EvanR	but you cant implement a protocol for an interface?
10:45	justin_smith	no, but you can implement an interface for an interface, and every protocol has an underlying implementation as an interface
10:49	pepijndevos	a protocol also generates an interface, right?
10:49	justin_smith	right, that's what I was saying
10:49	pepijndevos	eh, right
10:51	mikerod	Didn't this get discussed yesterday and puredanger ended up saying that Rich had no particular problems with allowing a protocol to extend a protocol or interface?
10:51	puredanger	I'm not sure that's the correct summary :)
10:51	pepijndevos	If anyone has any performance advice, I'd be very happy. This code is a lot slower than equivalent imperative Scala: https://www.refheap.com/c337db72c94175657d1217372
10:51	puredanger	protocols can definitely extend to interfaces now
10:52	llasram	Well, the protocol implementation lookup definitely works pretty hard to do the right thing for interfaces
10:52	mikerod	I've always been torn on why protocols do not allow the extension to other protocol/interfaces like the interfaces do. I tried to think it was idiomatic in Clojure, but that doesn't seem true when looking at the clojure.lang.* impl's
10:52	EvanR	what exactly does protocol extend protocol mean anyway, have an implementation? or is this inheritance
10:52	puredanger	it is not inheritance
10:52	mikerod	EvanR: inheritance is what I'm thinking
10:52	puredanger	at least I don't think of it as inheritance
10:52	mikerod	Type hierarchy inheritance is mostly my focus
10:53	puredanger	it means an implementation of the protocol exists for a type
10:53	mikerod	I see a lot of interface inheritance used in clojure.lang. If Clojure is mostly against that sort of thing, why is it done so pervasively there?
10:53	puredanger	I personally think it would be useful to extend protocols to other protocols. that introduces some problems, but I think it would allow abstraction layering (not concrete implementation layering) that would be useful. I do not know whether Rich would support that or not.
10:54	puredanger	interface inheritance is fine
10:54	puredanger	it's concrete extension that is a no-go
10:54	mikerod	puredanger: yes I agree and see that concrete extension is no good and is the main issue on this topic I think
10:54	EvanR	what is concrete extension
10:54	justin_smith	pepijndevos: where does that Node class come from?
10:55	puredanger	class extends class
10:55	EvanR	and in this case extends means inheritance
10:55	mikerod	I guess if I want the "isa" relationships for protocols then Clojure does support ad-hoc hiearaches or I can just drop down and extend protocol generated interfaces
10:55	pepijndevos	justin_smith line 27
10:55	puredanger	EvanR: yes, talking in Java terms atm
10:55	justin_smith	pepijndevos: d'oh, I must not be fully awake yet
10:55	EvanR	and "isa" means, is a subtype? a isa b means a works wherever b works?
10:56	puredanger	pepijndevos: you're using boxed math for one thing
10:56	mikerod	EvanR: I mean if I have a protocol for Animal and I have a protocol for Dog and I have a class that implements Dog, let's call it ActualDog, I'd like to be able to say that ActualDog "isa" Animal
10:57	puredanger	EvanR: this is not precise enough wrt concrete class vs interface
10:57	mikerod	(dumb example of course :) )
10:57	puredanger	mikerod: right, you can extend ActualDog to Animal and ActualDog to Dog
10:57	pepijndevos	puredanger, enlighten me. You mean I should use +' and friends?
10:57	EvanR	mikerod: without implementing Animal?
10:57	puredanger	but you can't extend Dog to Animal
10:58	mikerod	puredanger: yes, it just requires more of a hunt to figure out all the things you must extend to
10:58	EvanR	shudders
10:58	mikerod	puredanger: I just think the maintenance barrier is a bit higher
10:58	puredanger	one trick for this is to extend Object to Animal, then check satisfies? and install an extension for the concrete type you've encoutnered
10:58	EvanR	how do i union two sets?
10:58	EvanR	,(union #{1} #{2})
10:58	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: union in this context, compiling:(NO_SOURCE_PATH:0:0)>
10:58	puredanger	EvanR: clojure.set/union
10:59	mikerod	puredanger: that is an interesting way
10:59	EvanR	,(clojure.set/union #{1} #{2})
10:59	clojurebot	#<ClassNotFoundException java.lang.ClassNotFoundException: clojure.set>
10:59	puredanger	mikerod: I've used it quite a bit and it works fine. note you only have to install it the first time you encounter the new concrete type
10:59	puredanger	after that there is an extension installed for the concrete type so it routes directly
10:59	justin_smith	pepijndevos: +' is the opposite of what you want. Boxed means each number is actually an object (usually of type java.lang.Long or java.lang.Double) instead of a primitive long or double type (not Objects). You need type hints for this.
11:00	mikerod	This isn't a huge barrier to me anyways. I just have a had a few cases where it has came up. The toughest part about protocols to me is still that you can't rely on a given type that `satisfies?` it to actually implement its functions.
11:00	puredanger	justin_smith: +1
11:00	mikerod	puredanger: that is pretty clever :)
11:00	pepijndevos	ah... can I do warn-on-boxed yet? Browsing jira....
11:00	puredanger	it actually came up in a talk at the very first conj and Rich said this from the audience
11:00	puredanger	pepijndevos: you can in 1.7 alphas
11:01	pepijndevos	I have those... so I'll try that.
11:01	puredanger	mikerod: chouser (I believe) tried to live-code it and it didn't go so well :)
11:01	mikerod	puredanger: the dangers of live coding I guess
11:01	puredanger	live coding suggestions from Rich no less :)
11:01	justin_smith	puredanger: I have an idea to put together a repo that is just a bunch of files with clojure.test, making assertions about whether reflection or boxing occurs, as a "living document" demonstrating where hinting is needed or useful and where it is not.
11:02	justin_smith	I may just work on that today.
11:02	mikerod	that just sounds intense
11:02	justin_smith	(capturing the reflection / boxing warnings via with-out-str)
11:03	puredanger	justin_smith: there are some examples of how to do that in the clojure tests if you want to steal
11:03	justin_smith	puredanger: awesome, thanks
11:03	puredanger	mikerod: you might find this useful - http://david-mcneil.com/post/3495351254/clojure-protocol-adapters
11:03	puredanger	David and I were working together when he wrote this and it's the same ideas
11:04	EvanR	mikerod: maybe this idea is more about "required prerequisite protocol of a protocol"
11:05	puredanger	and then of course, a protocol is nothing more than a map with a well-known structure. you can also just muck with it directly to do all kinds of advanced stuff.
11:05	pepijndevos	so is it unchecked-math?
11:06	justin_smith	puredanger: my spidey-sense tells me that could get very ugly if misused...
11:06	puredanger	pepijndevos: (set! unchecked-math true)
11:06	EvanR	advanced, powerful ;)
11:06	puredanger	or (set! unchecked-math :warn-on-boxed) if you want the warnings
11:06	justin_smith	pepijndevos: I think the warnings turn on with unchecked-math - you may or may not need warn-on-reflection turned on too (regardless, you want both if you care about perf)
11:07	puredanger	warn-on-reflection is separate, but you probably should use that too
11:07	justin_smith	cool, thanks for the info
11:07	justin_smith	(inc puredanger)
11:07	lazybot	⇒ 23
11:07	puredanger	I did the boxed warning work after reading way too much bytecode for the Alioth perf stuff :)
11:08	puredanger	justin_smith: you could certainly abuse it :) great power / great responsibility /etc :)
11:08	justin_smith	haha, nothing motivates better than having your own itch to scratch
11:08	justin_smith	puredanger: I did mention spidey-sense for a reason
11:08	puredanger	Clojure leaves its internals open. if you have the ability to use them for good (and are willing to accept the maintenance costs associated), go for it.
11:09	EvanR	theres the ability to mess with internal junk for idiosyncratic purposes then theres whether you will encourage people to try it
11:09	EvanR	in ruby, both are true
11:09	EvanR	across the board
11:09	EvanR	and its terrible
11:11	mikerod	(inc puredanger)
11:11	lazybot	⇒ 24
11:11	mikerod	puredanger: thanks that link is good. I haven't seen it before.
11:11	mikerod	EvanR: yes that is the idea
11:11	mikerod	EvanR: the link pretty much captures the issue though I think for the most part
11:12	EvanR	mikerod: for a sense of required anything, maybe a first step is to require a whole protocol to be implemented by a single class?
11:13	EvanR	otherwise we can add new requirements through project documentation at will, if the system doesnt help
11:13	mikerod	EvanR: are you talking about the idea of a given type possibly not implementing a "required" protocol function that you need?
11:13	EvanR	yesterday i heard you dont have to implement all the methods of a protocol, and that confuses me
11:14	justin_smith	yeah, clojure does not force full protocol or interface implementation
11:14	EvanR	thats like, a prerequisite before that other prerequisite
11:15	EvanR	on the other hand its not like its ensuring you follow an interfaces spec either, even if you do have an impl
11:15	EvanR	so back to policy docs
11:15	justin_smith	right, that's a turing complete problem I think
11:15	EvanR	depending on the spec language
11:16	EvanR	specs involving meta physics propositions i dont expect to be computer assisted any time soon
11:16	pepijndevos	I wonder how big a difference unboxed math makes... we'll know in a minute.
11:17	puredanger	if you're doing math, 2-3 orders of magnitude :)
11:18	puredanger	but if that's not your bottleneck, then won't matter of course
11:22	EvanR	is there something like update-in but just sets the value instead of applying a function
11:22	EvanR	i know constantly can do it but thats such a long word
11:22	puredanger	assoc-in ?
11:22	EvanR	sweet
11:23	EvanR	blast
11:23	puredanger	it does what you want, just doesn't follow the update form
11:23	puredanger	since it's not an update
11:25	puredanger	(inc crossclj)
11:25	lazybot	⇒ 8
11:25	puredanger	once again, super helpful as I research things http://crossclj.info
11:32	ajmccluskey	Is there a neat way to flatten a nested map entry? Have {:A {:B :C}}, want [:A :B :C].
11:32	EvanR	,(flatten {:A {:B :C}}
11:32	EvanR	,(flatten {:A {:B :C}})
11:32	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading>
11:32	clojurebot	()
11:32	ajmccluskey	{:A {:B :C}} is meant to be a map entry there, not a whole map.
11:32	ajmccluskey	EvanR: yeah, that surprised me too :p
11:33	mikerod	EvanR: justin_smith what I wish there was available for protocols was a way to at "check" if a given object implements a function
11:33	EvanR	after re-reading the doc i would expect it to crash on maps
11:33	mikerod	instead of just throwing something liek an AbstractMethodError
11:33	mikerod	could always try-catch for control flow though! :P
11:33	mikerod	I tend to implement my protocols on Object with some special value like ::undefined
11:33	EvanR	better, assume they implemented it, what is the reason to support partial protocol impls?
11:34	mikerod	then control flow around that in functions that expect some functions to be implemented, but can try to recover if they are not
11:34	EvanR	sounds backwards from the perspective of a library writer
11:36	mikerod	by "recover" I mean do something that makes sense if possible
11:36	EvanR	sends an email to the person responsible for the partially defined thing to get them to complete it?
11:37	ajmccluskey	mikerod: agree with EvanR - sounds like a lot of work. I would go with expecting someone who says they implement a protocol to, you know, implement it
11:37	mikerod	ajmccluskey: I suppose
11:37	EvanR	i mean if they wanted to put a dummy that just crashes, they can
11:37	mikerod	AbstractMethodErrors it is then ;)
11:37	ajmccluskey	mikerod: wait, are you doing anything safety critical? I'm not going to die on the table because of this am I?
11:38	EvanR	or if the protocol is designed to be partially implemented, require an in-band method to describe that officially (or use more than one protocol)
11:38	mikerod	I actually wish even in the Java side that you could mark methods in a way that makes it clear yo do not implement them. Optional interface methods are very strange to me
11:38	mikerod	If an interface has optional methods, it sounds like a broken abstraction because you dont' know what the contract is of the objects your given
11:39	mikerod	http://docs.oracle.com/javase/7/docs/api/java/util/Collection.html
11:39	mikerod	and the UnsupportedOperationException
11:39	mikerod	for reference http://docs.oracle.com/javase/7/docs/api/java/util/Collection.html#add(E)
11:39	mikerod	I get it here, I think the interface should have been 2 interfaces
11:40	mikerod	The whole Immutable vs Editable or w/e
11:40	EvanR	badly design protocol support
11:43	yocapybara	anyone have any opinions on what the most performant way to get a digest (like md5 or sha1) from a clojure map?
11:43	mikerod	From the protocol perspective, the only reason I could see not requiring all functions on a protocol to be implemented is for some dynamic development. However, for "real" stuff I can't really see why there would be partial impl's.
11:43	mikerod	And protocols should be small to avoid the issue of having too much to implement
11:43	yocapybara	I pulled up pandect but running (sha1 {:a "b"}) gives me an error that there's no implementation of :compute-sha1686 for PersistentArrayMap
11:49	EvanR	,(values {:a 1 :b 2})
11:49	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: values in this context, compiling:(NO_SOURCE_PATH:0:0)>
11:49	EvanR	,(keys {:a 1 :b 2})
11:49	clojurebot	(:b :a)
11:51	ajmccluskey	,(vals {:a 1 :b 2})
11:51	clojurebot	(2 1)
12:03	justin_smith	mikerod: the general approach in Clojure is that if something is needed in dynamic development, it is valid. The differences between work in the repl and what works in files are actively minimized, and I actually think that is a good thing.
12:13	EvanR	if i were going to make a mutable data structure, what do i use. vars?
12:15	nkoza	evanr: you can use deftype, it supports mutable fields
12:15	justin_smith	EvanR: a var is just a mutable container, the thing in it doesn't mutate, it just points at a new thing when reassigned
12:15	justin_smith	EvanR: you can also use java.util.HashMap, or arrays, or whatever
12:16	puredanger	deftype supports marking fields with ^:unsynchronized-mutable or ^:volatile-mutable hints
12:16	clojurebot	Gabh mo leithscéal?
12:16	EvanR	my idea was to put the var in something as a mutable field
12:17	dnolen_	Bronsa: you haven't tried dead code elimination with tools.analyzer have you?
12:17	puredanger	why?
12:17	justin_smith	if you ever use a thread, an atom or ref may be a better pick than a var for that
12:17	clojurebot	because that's not how macros work
12:17	EvanR	but it sounds like i need a deftype
12:17	dnolen_	EvanR: is there some reason an atom does not suffice?
12:17	puredanger	putting a var in a mutable field of a deftype sounds like the wrong answer to most questions :)
12:17	EvanR	yes
12:18	EvanR	puredanger: two different ideas, not combined
12:18	puredanger	good :)
12:19	Bronsa	dnolen_: no, doing dead code elimination in clojure is nearly impossible without altering the language semantics. but arrdem should have done some tree shaking with oxcart -- which has cljs-like semantics
12:21	EvanR	i have a map of references to mutable objects, each having two mutable fields. so i guess a regular map in an atom for the top level would work, but the important part is that the map entries might point to the same object
12:21	Bronsa	dnolen_: sorry, I blindly assumed you meant tree shaking with "dead code elimination", was I wrong?
12:22	EvanR	in my mind the values are refs to objects, rather than regular values
12:22	OscarZ	was thinking of core.async.. are channels usually used as local variables that die after some function call or does it make sense to create some kind of "global" channel that could be used for multiple requests ?
12:22	dnolen_	Bronsa: not wrong, but what is the problem exactly if it can be summarized?
12:23	puredanger	EvanR: atoms (and refs etc) expect their values to be immutable. updates via swap! to an atom may be retried, which is a bad idea with mutable objects.
12:23	EvanR	for the deftype, its required to put ^:volatile-mutable ? the method name to set a field must be set-foo! ?
12:24	EvanR	puredanger: that part should be ok, because updating the map is its own operation, nothing is getting mutated there. but the objects would be modified some other way. a map of refs is immutable
12:24	Bronsa	dnolen_: in clojure? w/ a resident compiler there's no way to know for sure if you're never going to need a Var.
12:24	EvanR	i dont know if im using the right terminology for refs
12:24	puredanger	the syntax to set mutable fields inside a deftype is: (set! <field> <expr>)
12:24	hiredman	tree shaking/dead code elimination is a whole program optimization, but in clojure the compilation unit is a single form
12:24	Bronsa	dnolen_: i.e. you could get it dynamically via resolve, eval
12:25	dnolen_	Bronsa: does not compute. For a production artifact with whole program optimization? I don't see how it's any different for JavaScript
12:25	dnolen_	production artifact doesn't need eval
12:25	dnolen_	well
12:25	dnolen_	"might not need"
12:25	EvanR	inside a deftype? eh.. maybe i need a record
12:25	puredanger	EvanR: records only have final fields
12:25	EvanR	whats a final field?
12:25	puredanger	EvanR: you can cheat with arrays though (which are mutable)
12:25	puredanger	EvanR: cannot be changed
12:26	dnolen_	Bronsa: in anycase this answers my question, no one has tried to do a Closure style tree shaking pass on the AST
12:26	Bronsa	dnolen_: right in cljs since there's no resident compiler, reified namespaces & the compilation unit is the ns/program tree shaking should be trivial
12:26	puredanger	EvanR: here's an example alioth program that uses deftype with mutable fields to do dirty fast things http://benchmarksgame.alioth.debian.org/u64q/program.php?test=knucleotide&lang=clojure&id=5
12:27	dnolen_	Bronsa: as to why I care, if some one had already started on this for Clojure than it would be nice to reuse for ClojureScript such that Google Closure only works on pre-shaken source
12:27	dnolen_	Bronsa: Scala.js is doing this and it can have a dramatic effect of advanced compile times
12:27	Bronsa	dnolen_: I mean, arrdem has -- but he needed to make some assumptions on the clj code
12:27	dnolen_	Bronsa: using tools.analyzer?
12:27	Bronsa	dnolen_: well then you might reuse his impl, one sec
12:27	Bronsa	dnolen_: yes
12:27	Bronsa	dnolen_: https://github.com/oxlang/oxcart/blob/master/src/main/clojure/oxcart/passes/tree_shake.clj
12:27	EvanR	ok so i would make a method set-foo! and implement it as (set! foo ...
12:28	dnolen_	Bronsa: great thanks
12:28	triss	hey all... I'm messing with lein-cljsbuild
12:28	triss	where can i find out/goog/base.js?
12:28	puredanger	EvanR: yes, you could do that. You can't define methods in a deftype though. Rather you define an interface or protocol and implement it in the deftype
12:28	EvanR	puredanger: and when passing the "deftype" value around, this is a ref to an object right
12:28	triss	if it's not there is my build likely to be misconfigured.
12:28	triss	?
12:28	dnolen_	triss: that's specified by :output-dir
12:29	puredanger	EvanR: yes, will be an object with real (public) fields that you could access via (.- obj field) too
12:29	Bronsa	dnolen_: I'm not much familiar with that code but IIRC all that's doing is trivially merging the var reach set of every def & removing from the program AST the defs not reachable
12:29	dnolen_	Bronsa: cool, I will take a look
12:29	triss	splendid thanks dnolen_
12:29	puredanger	EvanR: just to reiterate, this is all rarely used, way off the beaten path stuff, specifically for the purposes of performance or implementing low-level stuff
12:30	EvanR	my algorithm is more straight forward in terms of mutable objects
12:30	EvanR	but maybe not rendered as clojure
12:31	puredanger	mutable objects are pretty intentionally hard to create or use in Clojure
12:31	puredanger	it should feel like you are actively fighting the grain
12:31	puredanger	as you are
12:31	EvanR	so far so good then
12:33	Bronsa	,(deftype x [^:volatile-mutable x] Object (toString [_] (set! (.x _) 1) "foo"))
12:33	clojurebot	sandbox.x
12:33	Bronsa	,(x. 1)
12:33	clojurebot	#<ClassCastException java.lang.ClassCastException: sandbox.x cannot be cast to compile__stub.sandbox.x>
12:35	EvanR	hmmm, a vector of two vars ;)
12:36	{blake}	At what point when you're building a web app do you say "OK, that's enough--too much--Javascript. I'm going to incorporate CLJS."?
12:36	bbloom	{blake}: mkdir
12:36	puredanger	(inc bbloom)
12:36	lazybot	⇒ 50
12:37	EvanR	cp ~/jsutils/* ~/project/js/
12:37	{blake}	Heh. 'k.
12:40	justin_smith	Bronsa: puredanger: I started a repo as a demo of when / how type hints are usefull. PR for demonstrating tricky or interesting corners of the domain are quite welcome. To keep things simple I am just testing for the existing warnings rather than testing for reflection or boxing directly.
12:41	justin_smith	https://github.com/noisesmith/hint-hint oops, almost forgot to link the repo
12:42	EvanR	i got it
12:43	EvanR	its a map of refs to regular clojure structures
12:48	EvanR	,(ref (ref 0))
12:48	clojurebot	#<Ref@4270f8: #<Ref@6c7a9: 0>>
12:48	EvanR	sweet
12:49	justin_smith	~ref
12:49	clojurebot	It's greek to me.
12:49	justin_smith	~refs
12:49	clojurebot	I don't understand.
12:49	justin_smith	~stm
12:49	puredanger	this kind of thing is generally a bad idea :) most people find they are happiest with no more refs than you can hold in one hand.
12:49	clojurebot	I don't understand.
12:49	justin_smith	I forget where the factoid about using refs went...
12:50	justin_smith	EvanR: the common thing to find is an atom holding a map. If alteration is heavily parallel, you will see a small number of refs, each holding a map.
12:52	hiredman	fewer
12:57	gfredericks	is there a general way to flip a bit on a Byte?
12:57	gfredericks	I had to special case the sign bit
12:58	gfredericks	which can't possibly be necessary
12:58	gfredericks	,(bit-shift-left 1 7)
12:58	clojurebot	128
12:58	gfredericks	^ can't really use that on a byte since it's out of range
12:58	puredanger	this sounds like the kind of thing where ztellman must have made a library :)
12:59	gfredericks	I could have 8 constants lying around but that seems sooper weird
12:59	bja_	I feel like there was a binary protocol library that ztellman built which would apply here
12:59	puredanger	gloss
12:59	puredanger	but I don't think it does
13:00	puredanger	java bytes are (stupidly) signed but surely there's a lib that does this right
13:01	gfredericks	what happens in java if you do (1 << 7) on a byte?
13:01	justin_smith	,(byte (bit-shift-left 1 7))
13:01	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: Value out of range for byte: 128>
13:02	justin_smith	,(set! unchecked-math true)
13:02	clojurebot	#<IllegalStateException java.lang.IllegalStateException: Can't change/establish root binding of: unchecked-math with set>
13:02	gfredericks	oh I hadn't thought of that
13:02	Bronsa	,(alter-var-root unchecked-math (constantly true))
13:02	justin_smith	,(binding [unchecked-math true] (byte (bit-shift-left 1 7)))
13:02	clojurebot	#<ClassCastException java.lang.ClassCastException: java.lang.Boolean cannot be cast to clojure.lang.Var>
13:02	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: Value out of range for byte: 128>
13:03	Bronsa	,(alter-var-root #'unchecked-math (constantly true))
13:03	clojurebot	true
13:03	justin_smith	,(byte (bit-shift-left 1 7))
13:03	clojurebot	-128
13:03	justin_smith	thanks Bronsa
13:03	Bronsa	justin_smith: binding won't work there, you need unchecked-math to be true at compile time
13:03	justin_smith	got it
13:03	Bronsa	and it's quite annoying
13:04	justin_smith	Bronsa: my approach to this in the hint-hint lib https://github.com/noisesmith/hint-hint/blob/master/src/org/noisesmith/hint_hint/capture_warnings.clj
13:04	gfredericks	thanks justin_smith Bronsa
13:06	Bronsa	justin_smith: uhm, does hint-hint cover only "when to use type hints" or can it also be "type hinting wtfs galore"?
13:06	justin_smith	Bronsa: the latter would be great - maybe in a separate namespace to differentiate useful tricks from gotchas
13:07	justin_smith	Bronsa: my motivation is that whenever questions come up here about type hints, we get a lot of "I think..." or "well actually..." so something that demonstrates all the points would be useful I think.
13:07	Bronsa	nice, I'll find some time to contribute
13:07	justin_smith	Bronsa: awesome! thanks.
13:18	EvanR	well thats not going to work very well either. so next is to do it all without mutation by simulating refs with indexes into another map
13:19	EvanR	and always use indirection
13:20	EvanR	forgotten objects with no references to them wont be collected by a gc, but since its just for a local algorithm it doesnt matter
13:21	justin_smith	EvanR: by local, do you mean it all happens in one thread, and in one let block?
13:22	EvanR	its a pure function, referentially transparent, and its not multithreaded
13:22	justin_smith	if so, you could get away with a java.util.HashMap / java.util.Arraylist
13:22	EvanR	well that would make sense
13:23	EvanR	is the java syntax attrocious though?
13:23	puredanger	much less attrocious than mutable deftypes and refs of refs :)
13:24	justin_smith	EvanR: ##(doto (java.util.HashMap.) (.put "a" 1))
13:24	lazybot	⇒ {"a" 1}
13:24	justin_smith	the doto is useful for chaining, because .put does not return the map
13:24	EvanR	well ill try the immutable way, since all my assoc-ins gets and update-ins started shattering when i tried to use mutable objects
13:25	Empperi	I'm curios, haven't ever tried this
13:25	EvanR	ill try the immutable secondary space first
13:25	Empperi	,(doto (java.util.HashMap.) (.put :a 1))
13:25	clojurebot	{:a 1}
13:25	Empperi	,(:a (doto (java.util.HashMap.) (.put :a 1)))
13:25	bja_	does java have something like python's __getitem__ that you could use?
13:25	clojurebot	1
13:25	Empperi	nice
13:25	Empperi	it should have worked but wanted to check
13:25	Empperi	bja_: what das __getitem__ do?
13:26	Empperi	does
13:26	Empperi	maybe I'll just google
13:26	bja_	I've implemented assoc-in/update-in with python's mutable collections with __getitem__/__setitem__
13:26	bja_	it's the dict/array item access syntax
13:26	bja_	foo[0], bar['baz']
13:26	bja_	it'd probably be some sort of interface in java
13:26	Empperi	,(doc get)
13:26	clojurebot	"([map key] [map key not-found]); Returns the value mapped to key, not-found or nil if key not present."
13:26	bja_	map's .get maybe
13:27	justin_smith	bja_: get-in / assoc-in I would guess
13:27	Empperi	,({"a" 1} "a")
13:27	clojurebot	1
13:27	Empperi	,(get {"a" 1} "a")
13:27	bja_	err, do get-in/assoc-in work with HashMaps of HashMaps?
13:27	clojurebot	1
13:27	justin_smith	,(get-in {:a {:b 0}} [:a :b]) ;; bja_
13:27	clojurebot	0
13:27	justin_smith	,(assoc-in {:a {:b 0}} [:a :b :c] 3) ;; bja_
13:28	clojurebot	#<ClassCastException java.lang.ClassCastException: java.lang.Long cannot be cast to clojure.lang.Associative>
13:28	justin_smith	,(assoc-in {:a {:b 0}} [:a :b] :c 3) ;; bja_
13:28	clojurebot	#<ArityException clojure.lang.ArityException: Wrong number of args (4) passed to: core/assoc-in>
13:28	justin_smith	err...
13:28	Empperi	:)
13:28	bja_	well, I meant java.util.HashMap. I know they obviously work in clojure (I was implmenting get-in/assoc-in/update-in in python because I missed them from clojure)
13:29	bja_	nvm, I'm just causing chaos at this point. ignore my line of questions/comments please :)
13:29	Empperi	,(get-in (doto (java.util.HashMap.) (.put :a (doto (java.util.HashMap.) (.put :b 1)))) [:a :b])
13:29	clojurebot	1
13:30	justin_smith	bja_: looks like that's your answer though
13:30	bja_	ah, nice
13:32	EvanR	(get-in the choppa)
13:32	bja_	so get-in works, but assoc-in/update-in won't work because HashMap is not clojure.lang.Associative
13:32	justin_smith	makes sense
13:37	ppppaul	hello clojures
13:43	justin_smith	hello
13:50	ppppaul	hello again
13:51	EvanR	is there dissoc-in
13:51	EvanR	or something
13:54	justin_smith	EvanR: I think flatland/useful may have dissoc-in
13:55	justin_smith	EvanR: https://github.com/flatland/useful/blob/develop/src/flatland/useful/map.clj#L81 it's here
13:56	ppppaul	flatland/useful no documentation :/
13:56	whodidthis	if i have a map (def cool {1 "a" 2 "b" 3 "c"}) whats a nice way to automatically bind the map values into globals cool-1, cool-2, cool-3, instead of using (get cool 1)
13:56	justin_smith	ppppaul: did you look at the link? the doc strings are pretty comprehensive
13:57	ppppaul	i'm looking through the code now
13:57	ppppaul	i like it. but even something like auto generated readme could be helpful
13:57	justin_smith	ppppaul: I think that's what this does https://github.com/flatland/useful/blob/develop/build-docs.sh
13:57	justin_smith	you could clone the repo and run it
13:58	ppppaul	:D
13:59	justin_smith	http://flatland.org/useful/ <- I think this is generated from that script
13:59	ppppaul	nice!
14:01	ppppaul	anyone who has some experiecne with lighttable and cljs i could use some help in #lighttable
14:03	ppppaul	trying to get my console logging to print to the lighttable console instead of the browser console
14:05	ppppaul	is this even possible?
14:07	BobSchack	ppppaul: Are you connected to the lighttable browser or an external one?
14:08	ppppaul	external
14:08	ppppaul	can't do HTTP stuff in the browser LT opens
14:08	ppppaul	CORS problems
14:09	BobSchack	What kind of HTTP stuff are you talking about? DOM manipulation?
14:10	ppppaul	HTTP requests to servers other than localhost
14:11	ppppaul	even GET requests fail
14:14	arrdem	justin_smith: so what's going on with hint_hint?
14:17	justin_smith	arrdem: the idea is that its a set of unit tests that prove where type hints are needed
14:18	justin_smith	arrdem: and any gotchas (eg. things that aren't actually useful)
14:20	justin_smith	arrdem: https://github.com/noisesmith/hint-hint/blob/master/test/org/noisesmith/hint_hint_test.clj current state of the tests - doing things that either provoke a warning or not, and using test/is to verify whether a warning happens
14:25	oggie	new to clojure and trying to understand how to do if /else logic... Anyone up for helping me out?
14:25	justin_smith	,(if true :ok :no)
14:26	clojurebot	:ok
14:26	justin_smith	,(if fase :ok :no)
14:26	BobSchack	ppppaul: Have you tried shoreleave remote (http://shoreleave.github.io/shoreleave-remote/#shoreleave.remotes.jsonp)?
14:26	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: fase in this context, compiling:(NO_SOURCE_PATH:0:0)>
14:26	justin_smith	,(if false :ok :no)
14:26	clojurebot	:no
14:26	oggie	justin_smith I tried that, but It doesn't work how I'm doing it
14:26	justin_smith	oggie: what are you actaully trying to do?
14:27	oggie	check to see if a username/password is not passed in (nil) and act differently
14:28	oggie	here's what I have
14:28	oggie	session (-> (if (not-any? nil? [username password]) (alia/cluster {:contact-points cluster :credentials {:user username, :password password}}) (alia/cluster {:contact-points cluster}) ) (alia/connect keyspace))
14:28	oggie	so don't add username/pass to the session if it's nil
14:32	justin_smith	oggie: that looks right, as long as the {:contact-points ...} map should be the first arg to alia/connect
14:33	justin_smith	the (alia/cluster {:contact-points ...}) that is
14:33	oggie	justin_smith it is supposed to be 1st
14:34	oggie	it works if I hard code the username/password in there and not use the if
14:34	oggie	hmm. maybe I do have it right
14:34	oggie	:-)
14:35	oggie	this is tough coming from Java for years
14:35	justin_smith	oggie: it may be clearer with let bindings instead of ->
14:36	oggie	ok
14:51	arrdem	is there a trick for looking a value up out of a map throwing if it doesn't exist?
14:51	amalloy	arrdem: use python
14:52	EvanR	uhm..
14:52	justin_smith	,(get {:b 0} :b (lazy-seq (throw (Exception. "boom"))))
14:52	EvanR	,(:abc {})
14:53	clojurebot	0
14:53	EvanR	,({} :abc)
14:53	clojurebot	nil
14:53	justin_smith	,(get {:b 0} :a (lazy-seq (throw (Exception. "boom"))))
14:53	llasram	Oh, slowness
14:53	clojurebot	nil
14:53	justin_smith	kinda hackish
14:53	clojurebot	#<Exception java.lang.Exception: boom>
14:53	justin_smith	actually works in a real repl though
14:53	Bronsa	justin_smith: you can never know when that'll throw though
14:53	llasram	I think clojurebot is just lagging
14:54	Bronsa	or even if that will throw at all
14:54	justin_smith	Bronsa: where would the gotcha be? if the value was not used?
14:54	Bronsa	justin_smith: yep
14:54	Bronsa	justin_smith: suppose (if (symbol? x) x 'foo)
14:55	llasram	&((fn safe-get [m k] (let [v (get m k ::not-found)] (if-not (identical? ::not-found v) v (throw (ex-info "not-found" {:m m, :k k}))))) {} :foo)
14:55	lazybot	clojure.lang.ExceptionInfo: not-found {:m {}, :k :foo}
14:56	llasram	lazybot: not so lazy today, now are you!
14:56	justin_smith	&((fn safe-get [m k] (if-not (contains? m k) (throw (Exception. "boom")) (get m k))) {} :foo)
14:56	lazybot	java.lang.Exception: boom
14:56	arrdem	llasram: that's nicer than the one I came up with. yoink!
14:57	arrdem	justin_smith and I had the same solution
14:57	Bronsa	,((fn safe-get [m k] (if-let [[_ v] (find m k)] v (throw (Exception. "boom"))) {} :foo)
14:58	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading>
14:58	Bronsa	well.
14:58	Bronsa	you get the idea.
14:58	justin_smith	Bronsa: oh yeah, find is a nice way to do that one
14:58	llasram	Oh nice, yeah
14:59	arrdem	won't that be identical to llasram's solution? both only do one lookup, whereas the contains? version will do two.
15:00	llasram	But Bronsa's doesn't depend on a magical sentinel which you can't ever have as a value in the map
15:00	justin_smith	it's more elegant, but only one lookup as with llasram's
15:00	arrdem	ah good point. In this context I don't care, the set of possible keys is strings only, but yeah in theory Bronsa wins.
15:00	arrdem	(inc Bronsa)
15:00	lazybot	⇒ 77
15:02	justin_smith	(inc Bronsa)
15:02	lazybot	⇒ 78
15:03	dnolen_	ClojureScript 0.0-2411 out
15:03	EvanR	why doesnt (fn [x] (prn x) x) work in the middle of a -> macro sequence
15:04	arrdem	EvanR: ((fn ..)) will.
15:04	EvanR	ohk
15:04	justin_smith	,(macroexpand '(-> 1 (fn [x] (prn x) x)))
15:04	clojurebot	#<CompilerException java.lang.IllegalArgumentException: Parameter declaration 1 should be a vector, compiling:(NO_SOURCE_FILE:0:0)>
15:04	arrdem	EvanR: (-> x (fn [x] x)) -> (fn x [x] x)
15:05	llasram	EvanR: bonus protip: (-> ... (doto prn) ...)
15:05	justin_smith	,(macroexpand '(-> foo (fn [x] (prn x) x)))
15:05	clojurebot	(fn* foo ([x] (prn x) x))
15:06	justin_smith	(inc llasram)
15:06	lazybot	⇒ 42
15:06	justin_smith	yeah that's actually the right way to do it
15:07	wirrrbel	I wanted to checkout yesql and ring / rook
15:07	wirrrbel	up until now my project was clojurescript only
15:08	wirrrbel	now I wonder where to put my sql file
15:09	justin_smith	wirrrbel: relative to the classpath means if you ask for "some/where/foo.sql" it can be in "src/some/where/foo.sql"
15:11	wirrrbel	justin_smith: thank you
15:36	EvanR	note to self core.match patterns do not introduce variables that shadow
15:36	EvanR	thought i was going insane
15:42	ppppaul	can i pretty print in cljs?
15:43	ppppaul	i'm having issues printing to the console :/
15:52	dnolen_	ppppaul: sadly no pretty printer built in - jonasen had a port of bblooms' fipp - might be useable unsure
15:53	dnolen_	and by "not built in" I mean I haven't received a clojure.pprint patch
16:03	ppppaul	hmm. i'll deal without one for now...
16:09	kenrestivo	is it kosher to use send for serializing synchronous access to i/o, where i want it to block?
16:11	kenrestivo	i suppose i could use send-off and then deref to block. but i'm wondering why not use send instead?
16:11	llasram	kenrestivo: Why are you using an agent if you want synchronous access?
16:12	kenrestivo	because some operations i want the agent send-off behavior.. others i don't
16:13	llasram	Can you share the broader context some?
16:13	kenrestivo	it's just a device
16:14	kenrestivo	so i've got an agent serializing access to it
16:15	amalloy	kenrestivo: deref doesn't block at all
16:16	llasram	Ok. Well, my 2 cents is that it doesn't sound like an agent is the best fit :-)
16:16	amalloy	it's not clear what difference between send and send-off is relevant here
16:16	kenrestivo	ah right, only on futures/promises, not on agents
16:16	justin_smith	kenrestivo: how about a thread reading a queue and writing to device, it also gets passed a promise that it delivers to when the write is done?
16:16	kenrestivo	yeah, i think the agent approach isn't going to work. thanks.
16:16	amalloy	kenrestivo: if you want exclusive, synchronous read/write access to a device, i'd just use a mutex
16:17	llasram	(inc amalloy)
16:17	lazybot	⇒ 201
16:17	amalloy	you can cobble together stuff with agents and await and blah blah blah, but like...locks aren't strictly bad
16:17	kenrestivo	was hoping to avoid j.u.c. interop, but i guess why not.
16:17	amalloy	kenrestivo: ?????? ##(doc locking)
16:17	lazybot	⇒ "Macro ([x & body]); Executes exprs in an implicit do, while holding the monitor of x. Will release the monitor of x in all circumstances."
16:18	dbasch	amalloy: there was a mixup, we sent rich hickey a cardboard cutout of you
16:18	kenrestivo	nice
16:18	amalloy	dbasch: that was you crouching in the bushes with a camera? i thought i'd become interesting to the paparazzi somehow
16:18	dbasch	it was hand-drawn
16:18	kenrestivo	amalloy: once again, thanks for showing me a new corner of clojure i had no idea existed
16:18	dbasch	no word from rich hickey yet
16:19	dbasch	the clojureazzi
16:20	EvanR	a queue with max size 1 would also work
16:21	EvanR	and you would have to muck with mutices
16:21	EvanR	wouldnt*
16:21	justin_smith	EvanR: I thought there was an implication that he only sometimes wanted to block
16:21	justin_smith	also, locking isn't much of a muck at all
16:22	EvanR	well P and V are crap
16:23	justin_smith	P and V?
16:23	llasram	Pevear and Volokhonsky?
16:23	EvanR	issue the lock command on a mutex object, then later... you had better issue the unlock on the same mutex
16:23	amalloy	he's a letter connoisseur
16:23	amalloy	EvanR: that's what locking guarantees to do
16:23	justin_smith	EvanR: that's now how locking works ##(doc locking)
16:23	lazybot	⇒ "Macro ([x & body]); Executes exprs in an implicit do, while holding the monitor of x. Will release the monitor of x in all circumstances."
16:24	EvanR	yes ok
16:24	justin_smith	all you do is wrap your code in the locking macro, it's not messy
16:24	EvanR	but im not sure exactly how even this corresponds to sometimes blocking
16:25	justin_smith	EvanR: he wanted to block on the write sometimes, and not others. So you want a queue with a larger size than 1, and a way to indicate the write completed (thus my suggestion of a promise)
16:25	EvanR	was the same implication also implying that you also sometimes forgo even doing your write?
16:25	EvanR	oh
16:26	EvanR	this policy is way past my concurrent semantics comfort level, crash when queue is maxed?
16:27	EvanR	block anyway
16:27	EvanR	dont write?
16:27	justin_smith	it would block on a full queue, let you go on your merry way otherwise. But a full queue indicates slowing you down is probably the right thing to do anyway.
17:10	_ak__	Is there anyone from north-west England, around Manchester or Liverpool here this evening?
17:23	FliPPeh	http://sprunge.us/LYDZ?clj - how's that for my first not-entirely-useless clojure program? Any obviously bad things?
17:26	kenrestivo	FliPPeh: at first glance, there are a couple things you're doing there that might already have functions in clojure.core to do what you want. but rewriting clojure.core functions can be a good learning exercise.
17:27	kenrestivo	,(doc keyword) ;; for example
17:27	clojurebot	"([name] [ns name]); Returns a Keyword with the given namespace and name. Do not use : in the keyword strings, it will be added automatically."
17:27	amalloy	kenrestivo: huh? he calls keyword himself
17:27	FliPPeh	,(keyword "something with spaces")
17:27	clojurebot	:something with spaces
17:27	FliPPeh	That looks evil
17:28	amalloy	FliPPeh: i don't see why you're converting to keywords at all
17:28	amalloy	just use strings as your map keys
17:28	FliPPeh	Well what I'm doing there is taking a string that may contain spaces and other weird things and turns those into simple dashes
17:28	FliPPeh	I could, but keywords feels more clojury
17:28	justin_smith	FliPPeh: another vote for just using strings as keys
17:29	amalloy	no. don't build keywords out of user-controlled data
17:29	FliPPeh	Alrighty
17:29	justin_smith	keywords are good if you are designing the data structure as literals, but getting it from somewhere else, just leave it a string
17:30	amalloy	otherwise i'd say this is all fairly reasonable, except that i'd use line-seq instead of slurp+lineify
17:31	amalloy	get a reader, call line-seq, then chunk those based on blank lines, then put the chunks into maps
17:32	dbasch	FliPPeh: also, you don’t need two separate requires
17:32	FliPPeh	Like partition-by on an empty line=
17:32	FliPPeh	?*
17:32	amalloy	sure, seems fine
17:33	EvanR	,(atom? (atom 0))
17:33	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: atom? in this context, compiling:(NO_SOURCE_PATH:0:0)>
17:34	dbasch	,(type (atom 0)) ;; EvanR
17:34	clojurebot	clojure.lang.Atom
17:34	FliPPeh	Ah, doesn't seem like line-seq will work here. Apparently it wants a buffered reader, but those don't work on /proc files
17:34	hiredman	what makes you say that?
17:35	FliPPeh	Well, that's what the repl is telling me
17:35	hiredman	what makes you say the repl is telling you that?
17:35	dbasch	FliPPeh: what error do you get?
17:36	kidpollo	Hola @dbasch
17:36	FliPPeh	Whoops pardon, I indeed misread
17:36	clojer	I've downloaded a JAR lib that I want to include in my Clojure project. Where should I put it and how to included in project.clj and any file which :require s it?
17:36	FliPPeh	"(line-seq (java.io.BufferedReader. (java.io.FileReader. "/proc/cpuinfo")))" does the trick just fine
17:36	dbasch	kidpollo: howdy
17:37	dbasch	clojer: is it something that wasn’t available in a public repository? Because if so, you don’t need to download it
17:37	kidpollo	I am trying to 1 up my clojure fu to the next level by hanging out with the cool kids :P
17:38	clojer	dbasch: Downloaded from an individual developer's website.
17:39	clojer	dbasch: I've already downloaded it. How to add it to the project?
17:39	sg2002	clojer: https://github.com/kumarshantanu/lein-localrepo
17:40	dbasch	that’s one way, or you could stick it in a local maven repo
17:41	dbasch	clojer: http://nakkaya.com/2010/03/16/adding-custom-libraries-into-local-leiningen-repository/ like this
17:41	clojer	dbasch: Do you mean in my .m2 repo?
17:41	dbasch	clojer: no
17:42	dbasch	you could hack your .m2 repo, but I wouldn’t recommend it
17:42	clojer	dbasch: Nothing fancy .... please :)
17:42	kenrestivo	kidpollo: or you could do 4clojure.com exercises
17:42	dbasch	clojer: I think the article I linked is the easiest way
17:42	dbasch	at least it’s what I did the last time I had to do this, a couple of years ago
17:43	whodidthis	https://www.refheap.com/94472 how do i get the symbol bound to n replace the last n in this macro
17:43	arohner	fun friday: Puppet Docs + HP Lovecraft in a markov chain: http://thedoomthatcametopuppet.tumblr.com/
17:44	kidpollo	kenrestivo: that also
17:44	clojer	dbasch: Kreist, what a lot of ceremony.
17:45	dbasch	clojer: well, you are including an artifact for which you don’t have the source and that doesn’t happen to be in a repository anywhere
17:46	dbasch	meaning, you’re using a dependency management tool (lein)
17:46	kenrestivo	there used to be a lein-local. i think it's deprecated, but it probably would't be to hard to have a lein plugin that wraps the mvn ceremony to install a local jar into ~/.m2
17:46	clojer	dbasch: Been spoiled by Ruby for too long, maybe. `require_relative <module>`. Done.
17:46	arohner	you can 'lein install' arbitrary jars
17:47	arohner	it generates a minimal pom for you
17:47	EvanR	heh require_relative
17:47	clojer	arohner: Now yer talkin'
17:47	EvanR	autoloading yall
17:48	kenrestivo	"gem install hairball" :-P
17:48	amalloy	clojer: well. that's nice in some ways, and lein is nice in others. clojure (and java) would much rather automatically download dependencies for you, from a repository, than have jars floating around your whole filesystem
17:48	arohner	clojer: I must be misremembering. you can certainly 'mvn install' :https://maven.apache.org/plugins/maven-install-plugin/usage.html
17:48	amalloy	are you sure this thing you're trying to use isn't in any repo anywhere?
17:49	amalloy	downloading jars by hand is a desperation move, a last resort
17:49	clojer	amalloy: I don't think so but I'll double-check.
17:50	arohner	clojer: and if you're doing a 'serious' project, it's often worthwhile to have your own private repo
17:50	arohner	using e.g. nexus or https://github.com/technomancy/s3-wagon-private
17:52	whodidthis	https://www.refheap.com/94473 or is this possible somehow, defin with the created symbol instead of n
17:52	kenrestivo	everything else, googling "libraryname maven" found some repo somewhere with it.
17:57	dbasch	whodidthis: I don’t understand what you’re trying to do
17:58	justin_smith	whodidthis: the way def works, it will always define n
17:58	whodidthis	ok, im a bit of a bad then
17:59	justin_smith	are you trying to pass a string to def-k and end up with that string being a def with the value "nice"?
17:59	whodidthis	yes :(
17:59	justin_smith	(defmacro def-k [k] `(def ~(symbol k) "nice"))
17:59	justin_smith	still very silly
17:59	justin_smith	but that should actually work
18:00	dbasch	whodidthis: look into intern
18:00	justin_smith	yeah, intern is actually a nicer way to do it, as long as the metadata that def adds isn't important to you
18:02	whodidthis	i wanted to find a nice way to get a maps keys and values deffed, like {1 "a" 2 "b"} => (def value-1 "a") (def value-2 "b")
18:02	EvanR	hah
18:02	EvanR	php extract
18:02	EvanR	only global
18:02	dbasch	whodidthis: that is a strange requirement
18:03	whodidthis	so i could access them with values/value-1 instead of (get values/values 1)
18:03	EvanR	if you use that a lot on a large map, you wont know heads from tails
18:03	dbasch	if you need to keep global state, you shouldn’t be defining variables willy-nilly
18:03	whodidthis	it was just a nice color scheme :(
18:12	amalloy	yeah, just leave it in the map. value-1 doesn't save a lot of characters compared to (values 1), and it avoids some other headaches
18:12	celwell	Hi, I'm trying to get a single Set of all page numbers. I have this code, which works, but I was wondering if I could get any feedback for a more idiomatic way of writing it.
18:12	celwell	(reduce #(apply conj %1 (s/split (:pages %2) #","))
18:12	celwell	#{}
18:12	celwell	[{:id 1 :pages "1,2,3,4"}
18:12	celwell	{:id 2 :pages "2,3,4,6,7"}
18:12	celwell	{:id 8 :pages "9,10,12"}])
18:15	EvanR	(concat (map (comp split-on-comma :pages)))
18:17	weavejes_	(mapcat (comp split-on-comma :pages) data)
18:17	weavejes_	(set *1)
18:19	celwell	Thanks, I like weavejes_'s answer the best.
18:20	amalloy	(reduce into #{} (map (comp split-on-comma :pages) xs)) is also possible
19:21	{blake}	OK, so I'm creating a login. I go to the page, get the login (sony/password) and now I want to go back to "/" with the "sony" in the session map. I was looking at "redirect" but it doesn't take a body.
19:31	{blake}	If something is a library and not in clojars, do you just download it and make it part of your own code?
19:32	zeapo	{blake}: that depend on the licence. Check if you can redistribute it.
19:33	xeqi	{blake}: it might be in http://search.maven.org/
19:35	{blake}	xeqi: 'tis not.
19:40	justin_smith	{blake}: for doing a redirect and also putting something in the session, maybe try (assoc (redirect url) :session updated-session)
19:40	justin_smith	redirect should return a response map I think
19:40	justin_smith	or, if that was a login, it could be (assoc (redirect-after-post url) :session updated-session)
19:40	{blake}	justin_smith: Thanks, lemme try.
19:42	{blake}	(inc justin_smith)
19:42	lazybot	⇒ 152
19:42	dbasch	{blake}: it is a clojure library and it’s not on clojars?
19:43	{blake}	I've SO got to run through all my compojure stuff again. I'm not thinking right at all.
19:43	{blake}	dbasch: Yeah, it's a little weavejester thing called "decorate".
19:44	dbasch	{blake}: ask weavejester to put it on clojars
19:45	dbasch	or fork it and do it yourself
19:45	amalloy	oh my gosh it's five years old
19:46	amalloy	it looks like a bad version of robert.hooke, or maybe just convenience wrappers over alter-var-root?
19:47	{blake}	It was more of an idle question. It's just what happens when you chase around the web looking for helpful information. Sometimes the most helpful (looking) stuff relies on ephemera.
19:54	justin_smith	{blake}: crossclj.info is good for seeing which libraries people are using
19:55	justin_smith	http://crossclj.info
19:55	justin_smith	and more usage often means more helpful
19:56	{blake}	justin_smith: Yeah, but in this case, I was looking for explanation and found this: http://blog.experimentalworks.net/2010/02/dealing-with-sessions-in-compojure/
19:56	{blake}	Which uses that "decorate" thing. Though I did manage to figure out that I didn't need it. So I got that going for me.
19:57	{blake}	Wow, midje's up there.
20:00	justin_smith	yeah, I was surprised it was so prevalent
20:01	justin_smith	aha, decorate is doing the "decorator pattern", which you can also do with standard ring middleware
20:12	{blake}	justin_smith: Right, I sorta guessed that. I read it and thought "Hey, isn't that what you always do with everything ring-based?"
20:29	thearthur	this core.logic SO question needs some attention: http://stackoverflow.com/questions/27324013/core-logic-unification-matches-value-in-map-but-not-key
20:35	amalloy	thearthur: you're arthur ulfeldt? the question's only been up for five hours, and it has three upvotes; i'm sure it will get some answers when someone qualified comes across it. and if it doesn't, you certainly have the resources to put a bounty on it
20:36	TEttinger	asked by shaft, amalloy
20:36	amalloy	TEttinger: yes, i see that. so?
20:36	thearthur	amalloy: thats me, yep. it's just bugging me and i'm impatient :-)
20:37	TEttinger	oh, i thought bounties were added by the asker
20:37	amalloy	anyone can put a bounty on anything
20:38	TEttinger	stack overflow/exchange is certainly different
20:38	justin_smith	thearthur: oh hi, I'm noisesmith on stackoverflow, we've crossed paths there a few times
20:38	amalloy	i mean, in practice most of the time people put bounties on their own questions because they really want an answer
20:39	amalloy	but some third party can do it if they want an answer too, or just if they think it was a good question that deserves an answer; when you have as much rep as arthur, spending 50 on someone else's question is no big deal
20:39	TEttinger	rep is precious! I have like 9!
20:40	thearthur	perhaps I should switch nicks to match everywhere else
20:41	thearthur	I'm unable to find an add bounty button on this question
20:42	amalloy	thearthur: you can't, because it's only five hours old
20:42	amalloy	you're supposed to let it simmer for a bit :P
20:42	thearthur	(dec thearthur)
20:42	lazybot	You can't adjust your own karma.
20:42	amalloy	or just like...mention dnolen_ and http://stackoverflow.com/questions/27324013/core-logic-unification-matches-value-in-map-but-not-key in the same line
20:43	TEttinger	dnolen_ with the underscore of inactiveness?
20:43	amalloy	he'll get it eventually, i imagine
20:43	TEttinger	there's also $mail
20:44	TEttinger	that's one of the more widely used features on my lazybot
20:50	amalloy	$mail TEttinger i heard you like mail
20:50	lazybot	Message saved.
20:52	TEttinger	$mail amalloy yes I do
20:52	lazybot	Message saved.
20:52	amalloy	$login
20:52	lazybot	You've been logged in.
20:52	amalloy	$unmail TEttinger amalloy
20:52	lazybot	Deleted unread messages from TEttinger to amalloy
20:52	amalloy	hacks
20:52	amalloy	$logout
20:52	lazybot	You've been logged out.
20:52	TEttinger	heh, I didn't know you had a login
20:52	TEttinger	nice
20:55	tuft	is there a repl client for clojuredocs.org? e.g. (clojuredocs cond) to see examples of cond
20:56	justin_smith	$grim clojure.core/cond is similar
20:56	lazybot	http://grimoire.arrdem.com/1.6.0/clojure.core/cond
21:01	andyf	tuft: github.com/jafingerhut/cd-client
21:02	andyf	tuft: But the data you get via the API is currently stuck at about sep 2014 when they upgraded the rest of the site from clojure 1.3 source to 1.6
21:03	andyf	There is an issue requesting updating the API data, too, at github.com/zk/ClojureDocs
21:18	timvisher-xubunt	anyone aware of a port of tools.trace to clojurescript?
21:20	justin_smith	timvisher-xubunt: I bet you could do some nice tracing and even step debugging with the browser's inspector
21:22	timvisher-xubunt	justin_smith: that's probably true. but i'm headless at the moment and would prefer to continue to be.
21:22	timvisher-xubunt	tools.trace is _so_ nice but it doesn't look like anyone's tried to port it yet
21:22	timvisher-xubunt	stuartsierra: i'm assuming you haven't heard anything?
21:23	timvisher-xubunt	actually, you stopped maintaining it iirc, sorry :\|
21:32	Jesterman81	hey ladies/gents, quick question. I have a clojure web app using hiccup with something like [:a {:href “/img/foo.jppg”}]
21:32	Jesterman81	do I have to manually add the context if I am deploying to a tomcat instance?
21:33	justin_smith	Jesterman81: it's easier if your app is at the root, I don't know if there is any nice automated way to add the context to links
21:34	justin_smith	Jesterman81: our approach has been to make a function that generates a route for a resource or endpoint, and call that
21:34	justin_smith	and let that function adjust for the context path etc.
21:34	amalloy	justin_smith: i think the only thing you can do is write a function like make-link, and have that function know what the context is
21:35	justin_smith	that also ends up helping when the client want's different URLs but you don't want to do a major app rewrite
21:35	justin_smith	amalloy: figures, yeah that's what we do
21:35	Jesterman81	thanks, I was hoping I just wasn’t missing something easy
21:36	justin_smith	you may get something about the context info from the container in the request map
21:36	justin_smith	couldn't hurt to dump the request map as you receive it in tomcat and look for something useful
21:38	Jesterman81	ill take a look at the request and see whats in there
21:40	justin_smith	another option would be using a config to export the context as a system property that the clojure app can then pick up
21:41	Jesterman81	thanks for the options. appreciate it
22:17	Frozenlock	In compojure, is it possible to apply different middlewares to different routes? (c/routes (-> r1 m1 m2 m3) (-> r2 m4 m5 m6)) ?
22:29	justin_smith	Frozenlock: yes. I am a little fuzzy on the details as I don't use compojure in anger myself, but I know that middlewares can be used to wrap individual routes
22:29	justin_smith	it should just be a question of function composition
22:30	Frozenlock	justin_smith: thanks
23:18	Frozenlock	AH! Found how to do it. Must use compojure.core/wrap-routes to wrap the routes only once they have been matched.
23:40	josiah14	I'm reading through a bunch of Clojure code seeing how much I can figure out/comprehend, and I ran across what looks like a very short lambda function which is a bit cryptic to me in syntax. Can anyone tell me at a high level what #(%2) does, and why calling reductions with it on a list of read-line functions requires an initial value of nil for every function in the list to get executed?
23:41	justin_smith	josiah14: ##(macroexpand '#(%2))
23:41	lazybot	⇒ (fn* [p1__13570# p2__13569#] (p2__13569#))
23:41	josiah14	the actual code is like, (reductions #(%2) nil (repeat n read-line)) where 'n' is some calculated number
23:42	justin_smith	does the above macroexpansion make sense?
23:42	justin_smith	equivalent: (fn [a b] b)
23:42	justin_smith	err
23:42	justin_smith	(fn [a b] (b))
23:43	josiah14	actually, I think so
23:43	justin_smith	it expects two functions, and calls the second one, ignoring the first
23:43	josiah14	yah, that's what I got from that. I'm still getting used to reading macros.
23:43	justin_smith	well, two things, and calls the second as a no arg function actually, to be more precise
23:43	josiah14	is there a better function I could use there so that i can eliminate the nil initial value
23:44	josiah14	I would have thought #(%1) would be like that one but call every function
23:44	josiah14	I can't remember what the error message was
23:44	justin_smith	well, the thing is the first version takes N args, and only calls the second one
23:45	justin_smith	so that's a really weird "reduce" in that it always throws away the accumulator
23:45	justin_smith	it would be much clearer as a doseq
23:45	justin_smith	(doseq [f (repeat n read-line)] (f))
23:45	josiah14	except I need the values returned from read-line
23:45	justin_smith	oh, reductions
23:45	justin_smith	sorry
23:45	justin_smith	it's not reduce, but reductions, so you do see each result
23:45	josiah14	yes
23:45	josiah14	basically
23:46	justin_smith	(doall (for [f (repeat n read-line)] (f)))
23:46	justin_smith	you still get all the results, but what it's doing is much more clear
23:46	josiah14	i thought there had to be somethnig simpler
23:47	josiah14	yah, it'll probably take me a bit to get the syntax down. I know conceptually what I want to do, but then figuring out how to say it in Clojure is proving tough for impure functions, yet
23:48	josiah14	but then, Haskell was tough in that way too (and it's looking like this will be easier than learning all that crap about Monads, Monad Transforms, Arrows, etc.)
23:48	justin_smith	the way I see it that there is a strategy of making immutable and pure very easy to do, and impurity a bit trickier
23:49	justin_smith	josiah14: the general rule of thumb that has worked for me is take everything you think may have to mutate, turn it into a function argument, and do chained / recursive function calls
23:49	justin_smith	that is pretty effective for translating imperative algorithms to functional world
23:49	josiah14	yah, same as in haskell
23:49	josiah14	it's IO that gets tricky, and event handling
23:50	justin_smith	you can also "cheat" by making a map holding a "state of the world" under various keys as one of the parameters
23:50	justin_smith	in clojure integrating io/events is a bit easier I think
23:50	justin_smith	it's handled more pragmatically at least
23:50	josiah14	yah, it's looking that way - just a matter of syntax
23:50	rritoch	josiah14: Cant you just map over #(%1) ? As far as I can tell that would produce the same results
23:50	rritoch	josiah14: (map #(%1) (repeat n read-line))
23:51	justin_smith	rritoch: that's what the for does, but I think for is more readable in that case
23:51	josiah14	rritoch, yes, that works out perfectly
23:51	josiah14	just tested in the repl
23:52	justin_smith	josiah14: beware that that is lazy
23:52	justin_smith	that is why I added the doall in my for version, to match the eagerness of reduce
23:52	josiah14	yah, I just need to get the syntax in my head, then I think all that effort I put into Haskell will start to pay off in terms of already knowing how to think functionally
23:52	josiah14	justin_smith: I'm used to lazy, so no problems, there
23:56	rritoch	justin_smith: Is reductions being depricated? I could be wrong but it seems reductions is replaced with map transducers that have "reduction state"
23:57	justin_smith	it carries no deprecation warning in the latest 1.7 alpha
23:58	justin_smith	but yeah, it may make a lot of sense to use a transducer