#clojure – 2010-01-03

2010-01-03

00:22	quizme	Did Rick Hickey use Clojure for the exit polling app? What did he use for persistence?
03:14	LauJensen	Morning team
03:18	polypus	hello
03:18	polypus	20 past midnight here
03:20	quizme	hi
03:21	replaca	hey Lau
03:21	quizme	how about we make a new company consisting of everybody on this channel
03:21	replaca	I thought that's what Dysinger was up to :-)
04:10	noidi	I see that optimizer had problems with xmonad... in case anyone else is getting grey screens with Java apps, this might help http://awesome.naquadah.org/wiki/Problems_with_Java
05:33	LauJensen	Anyone in here with some flair for design, who can help me out 2 minz?
05:38	LauJensen	Ok I guess that was a long shot in the forum for Lispniks :)
05:39	timothypratley	chuckle maybe if you were after macro design someone would chime up :P
05:39	timothypratley	but I'm guessing something more visual?
05:41	LauJensen	You guessed right
05:42	_alex	I do design
05:43	LauJensen	Great ---> Priv :)
07:16	zakwilson	While trying to build the neman libs with Clojure 1.1, it complains "clojure#clojure;svn1322: not found". I've never built these before so I don't know if this is a version conflict or something else. I also don't really know my way around ant, ivy or other Java-universe tools that well, so a pointer in the right direction would be appreciated.
07:47	Chousuke	zakwilson: my first guess would be that the build script is horribly outdated.
07:49	zakwilson	Chousuke: I'm sure it is. I just don't know what to do about it.
08:01	hoeck	zakwilson: you could simply set your classpath to contain all those clj files, and then search for gen-class to figure those out who need AOT compilation and do it by hand
10:05	noidi	how might I go about using penumbra in a leiningen project?
10:20	jamescarr	hi
10:20	jamescarr	is there a mavenized jar for the clojure jsr-223 implementation?
10:39	Licenser	mavenized sounds fun .P
10:52	somnium	urk, what do you do if someones squatting on your group at clojars (with a fork of your project)?
11:20	mebaran151	how do I run a zipper on a nested map
11:49	edbond	how to fix 'java.lang.ClassCastException: clojure.lang.LazySeq cannot be cast to clojure.lang.IFn'?
11:51	guru	typically you program contains an error like this
11:51	guru	,((lazy-seq '()))
11:51	clojurebot	java.lang.ClassCastException: clojure.lang.LazySeq cannot be cast to clojure.lang.IFn
11:51	edbond	guru: I suppose this is because of map
11:52	guru	post code snippet
11:52	guru	plz
11:52	lisppaste8	edbond pasted "java.lang.ClassCastException: clojure.lang.LazySeq cannot be cast to clojure.lang.IFn" at http://paste.lisp.org/display/92961
11:53	guru	could you already isolate the error?
11:53	edbond	its somewhere in row-vals
11:53	guru	do you know the function it occurs in?
11:53	edbond	function max-in-row
11:54	edbond	get-all-variants works
11:54	edbond	(get-all-variants int-grid 4 4) => ((51 99 64 2) (51 3 67 20) (51 67 63 89) (51 60 14 57))
11:54	guru	(get (grid) y0)
11:55	guru	should be (get grid y0) i guess
11:55	guru	or just (grid y0)
11:55	guru	(vectors are functions with the index as their parameter)
11:56	guru	vectors are functions is a bit misleading
11:56	edbond	(int-grid 4) doesnt works
11:57	edbond	but ((int-grid) 4) works
11:57	guru	if you define a vector, there is a function with the same name
11:57	guru	yep
11:58	guru	(get grid y0) should work
11:58	edbond	thats why I used (get (grid) y0)
11:58	guru	yeah, just get rid of the get
11:58	edbond	anyway I still have the same exception
11:58	guru	ah uh
11:58	edbond	lazyseq -> ifn
12:01	edbond	btw (map #(%) (range(4))) throw similar error
12:02	guru	,(map (fn [x] x) (range 4))
12:02	clojurebot	(0 1 2 3)
12:02	guru	(map #(%) (range 4))
12:03	guru	a #(...) style function must start with an IFn
12:03	guru	so it tries to execute the %, which is intended as return value
12:03	edbond	I got it, thanks
12:04	edbond	,(map (fn [x] x) (range 4))
12:04	clojurebot	(0 1 2 3)
12:04	guru	and by (range(4)) you say give me the range starting from 0 up to the value that the 'function' 4 returns
12:04	guru	oh, but i was wrong on that (get (grid) y0) line
12:05	guru	your version is right
12:05	guru	since grid is a function, which returns a lazy seq
12:09	guru	the problem still remains, i guess?
12:09	edbond	yep
12:11	guru	did you replace that line
12:11	guru	row-vals (map #(get-all-variants grid % y0) (range (count row)))]
12:11	guru	with the (fn [x] ... version?
12:14	edbond	no
12:14	guru	well
12:14	guru	there is no reason too ;-)
12:14	guru	sry
12:18	guru	take a look at the last line of max-in-row
12:20	guru	r u still with me?
12:37	mebaran151	do zippers work with nested maps?
12:40	guru	mebaran: http://clojure.org/other_libraries
12:40	guru	and there the bottom of the page
12:44	edbond	guru: sorry, had to leave.
12:44	guru	wb ;-)
12:45	guru	so, have a look at the last line of max-in-row
12:45	edbond	I have fixed the function
12:46	edbond	did, row-vals (mapcat (fn [x] (get-all-variants grid x y0)) (range (count row)))]
12:46	guru	nice
12:46	edbond	and removed () from row-vals at the end
12:47	guru	that mapping from the re-seq results to bigint might be unneccessary
12:47	guru	for that (fn [x] (get-all-variants grid x y0)) part, you might as well write #(get-all-va...)
12:47	guru	i was wrong on this one
12:48	guru	you are doing a conversion from int to bigint right?
12:50	edbond	no, from string to bigint, I had problems with this
12:52	guru	ok, i use sth like (map read-string (re-seq #"\d+" %)) for these things
12:52	guru	u should know that u donÄt have to worry about overflows
12:53	guru	if an overflow would occur, clojure converts you number type into one which can hold bigger numbers
12:54	guru	,(type ( + 1 1))
12:54	clojurebot	java.lang.Integer
12:55	guru	,(type 1000000000)
12:55	clojurebot	java.lang.Integer
12:56	guru	(type (* 1000000000 1000000000))
12:56	guru	,(type (* 1000000000 1000000000))
12:56	clojurebot	java.lang.Long
12:56	guru	,(type (* 1000000000 1000000000 1000000000))
12:56	clojurebot	java.math.BigInteger
12:57	edbond	I had to convert string to integer, don't know about read-string
12:57	guru	yep
12:57	guru	and bigint isnt that bad here
12:57	guru	since it "naturally" takes a string
12:57	guru	but if you dont need big numbers
12:57	guru	just use read-string
12:57	guru	which converts about any number
12:58	guru	i was glad too, that i found that function
12:58	edbond	,(max [1 2 4])
12:58	clojurebot	[1 2 4]
12:58	edbond	how to use max function?
12:58	guru	,(max 1 2 4)
12:58	clojurebot	4
12:59	guru	,(apply max [1 2 4])
12:59	clojurebot	4
12:59	edbond	thanks
12:59	guru	np
13:00	MenTaLguY	hello
13:01	MenTaLguY	what's the best option for a persistent queue data structure in Clojure?
13:02	polypus	do you mean persistent in the clojure sense?
13:03	edbond	heh, solved :)
13:03	edbond	(time (solve int-grid))
13:03	edbond	"Elapsed time: 8554.364876 msecs"
13:03	edbond	guru: thanks
13:03	guru	you're welcome
13:06	MenTaLguY	polypus: yes.
13:19	guru	mentalguy: http://markmail.org/message/brvozelsgmr5a3ba
13:19	MenTaLguY	oh, that's interesting
13:20	MenTaLguY	Why it isn't exposed as part of the API?
13:20	lopex	MenTaLguY: it's also use here http://www.bestinclass.dk/index.php/2009/09/scala-vs-clojure-round-2-concurrency/
13:20	guru	i dunno, looks pretty useful
13:20	mebaran151	how do try and finally interact with lazy-seq?
13:21	mebaran151	is finally immediately called or is does it wait until the seq is entire consumed?
13:21	replaca	MenTaLguY: good question. If you want blocking behavior, also look at clojure.contrib.seq-utils/fill-queue
13:21	MenTaLguY	don't need blocking, just a simple queue
13:22	replaca	cool
13:22	MenTaLguY	thanks
13:31	Licenser	hmm I've some problems using lein and swank :/ they refuse to see eachother :(
13:31	the-kenny	PersistentQueue isn't mutable, right?
13:33	MenTaLguY	correct
13:35	Licenser	okay I was just stupid :)
13:39	chouser	mebaran151: if something producing a step of a lazy seq throws an exception, it happens right then when that step is realized.
13:40	chouser	I'm not sure if that answers your question.
13:40	MenTaLguY	what happens if that step is subsequently re-requested?
13:41	mebaran151	chouser, I was thinking of ensuring that I closed certain iterators
13:42	mebaran151	basically I'd like to be able to make a seq, that when it goes to garbage collection, will be closed
13:42	mebaran151	how does the usual java idiom of finally work with this
13:44	Chousuke	hm... it doesn't?
13:44	Chousuke	finally is for doing cleanup when you get an exception, not when some object is garbage-collected :/
13:44	mebaran151	finally is for making sure something is called no matter what
13:44	mebaran151	exception or not
13:45	Chousuke	well, yeah
13:45	Chousuke	but it's got nothing to do with GC :)
13:45	mebaran151	but if I call seq on the iterator (which could be a pretty big iterator), I might not use all of it
13:45	mebaran151	however if it prematurely calls finally, I won't be able to get the next item
13:45	Chousuke	in that case, you just need to take care of closing the iterator manually somehow.
13:45	mebaran151	right now, I'm getting basically first item, then an exception that states everything was closed to early
13:46	mebaran151	exactly!
13:46	mebaran151	I want to preserve laziness and make sure when I'm done with the lazy thing, it cleans itself up, without my library user having to know anything about transactions or iterators or nothin'
13:47	Chousuke	I wonder if that's even possible.
13:47	Chousuke	the seq could keep the iterator open somehow perhaps, but then the problem would be how to ensure it's cleaned up :/
13:54	chouser	you can try to use weak references to do some clean-up action when a thing get GC
13:55	chouser	but this is generally not recommended
13:59	mebaran151	so essentially I can't hide the evils of db iteration
13:59	mebaran151	is there anyway to be informed when a seq goes out of scope?
14:15	quizme	does the enclojure plugin work for netbeans 6.8?
14:15	quizme	i'm on linux ubuntu 9.10. anybody know of a good clojure editor ?
14:16	guru	enclojure works for 6.8
14:16	the-kenny	quizme: Emacs + Slime
14:17	quizme	ok
15:17	danlei	I'm looking for a video where rich talked at some kind of lispers metting, where he demonstrated ants (not clojure fore java/lisp programmers) any ideas what that was?
15:17	danlei	*meeting
15:17	hiredman	~blip.tv
15:17	clojurebot	blip.tv is http://clojure.blip.tv/
15:17	danlei	hm
15:18	danlei	aaah
15:18	danlei	clojure concurrency ...
15:18	danlei	thanks hiredman
15:19	danlei	in a hurry ... see you guys
15:32	edbond	how to profile clojure programs?
15:36	pdk	you should be able to profile them with regular java profiling tools
15:36	pdk	recent jdk versions come with a profiler, let's see if i recall the name
15:37	pdk	jvisualvm
15:37	pdk	i think you can run it from the command line if javac is in your path
16:11	djork	What's the state of Clojure jobs?
16:11	djork	Is there such a thing yet? :P
16:18	ohpauleez	djork: There are two companies that use clojure just in the Philadelphia region
16:18	ohpauleez	one of them is Comcast
16:18	ska2342	djork: it probably depends on where you live. Many recruiters will probably honor if you got it under your sleeve, even though the companies dont use Clojure(yet).
16:19	ordnungswidrig	re
16:19	djork	DC area. Not really interesting in working in DC though.
16:19	djork	http://craiglook.com/all.html?q=clojure&m=0 aww, zero listings
16:19	ohpauleez	The other company rights highly available messaging systems for financial companies
16:19	djork	interesting
16:19	ohpauleez	writes*
16:20	djork	seems like more of an Erlang niche
16:20	djork	(just saying)
16:20	djork	(not that I wouldn't try it in Clojure myself)
16:21	ohpauleez	clojure is one piece of the puzzle
16:21	ohpauleez	there is some erlang in the solution, as well as RabbitMQ, ruby (on rails) and standard Java
16:22	ska2342	Many companies just got to evaluating Clojure which is probably not done in the wide public. It is quite easy to integrate Clojure for internal tools (like testing or command line interfaces) where Java is used. It's probably harder to persuade a customer of this new technology.
16:22	ohpauleez	One large engineering group in Comcast is using it, and adopting it more extensively
16:23	ska2342	Learning Clojure is a bet (besides being fun :-)
16:23	ohpauleez	a second group (also very large) is going to put it up for trial the beginning of this year for some stuff
16:27	hiredman	ohpauleez: interesting about comcast
16:36	ohpauleez	totally
16:36	pdk	djork if you google lispjobs it covers clojure as well
16:36	djork	good tip, thanks pdk
16:37	hiredman	my gui repl starts up 21 threads just to sit idle
16:38	patrkris	any clever libraries available that makes talking to web services easy in Clojure?
16:38	hiredman	clojure-json
16:38	the-kenny	clojure-http-client
16:38	patrkris	sorry, I mean for SOAP-based web services
16:38	technomancy	patrkris: clojure.http.client has a "resourcefully" ns that you might like
16:39	technomancy	eww
16:39	patrkris	yeah, I don't like SOAP either
16:39	technomancy	=(
16:39	patrkris	technomancy: resourcefully is for SOAP stuff?
16:40	technomancy	no, just for REST
16:40	hiredman	I think I call future for each evaluation (yaya threadpool!)
16:41	patrkris	technomancy: stupid question, did you mean clojure-contrib?
16:41	patrkris	not that it matters much in the case of SOAP
16:42	technomancy	patrkris: no, this is separate: http://github.com/technomancy/clojure-http-client
16:42	patrkris	ah
16:48	hiredman	http://www.thelastcitadel.com/images/Screenshot-Repl.png
17:05	Immutable7	are there any libraries for networking? eg like mina?
18:02	quizme	does enclojure work with netbeans 6.8 ?
18:27	the-kenny	Why is something like rename-keys in clojure.set?
18:43	mebaran151	technomancy, I have a set of unit tests for my library in subfolder test
18:43	mebaran151	how do I get lein test to run them
18:43	mebaran151	they just use clojure.test
18:45	ikitat	$ lein test
18:45	mebaran151	I use lein test
18:45	mebaran151	but it blows up, complaing there's no clojure
18:45	mebaran151	but there is!
18:46	ikitat	clojar.jar in your lib folder?
18:47	technomancy	mebaran151: did you do lein deps?
18:47	mebaran151	yeah
18:49	mebaran151	I apologize wrong error
18:49	mebaran151	it can't find my test clj files
18:49	mebaran151	I keep my tests in test
18:49	mebaran151	anyway to add that to the search path
18:51	technomancy	mebaran151: it should be by default, but you can add a :test key to project.clj
18:51	mebaran151	what namespace should my tests live in?
18:51	technomancy	any namespace is fine
18:51	technomancy	it will just run all the tests in all the namespaces in the test/ dir of your project
18:52	technomancy	sorry, the :test-path key in project.clj
18:52	technomancy	as always, test namespaces need to match the file they're stored in
18:52	mebaran151	well mine are in com.bebop.appledelhi.bdb-test
18:52	mebaran151	and it picks up that those are tests to run
18:52	mebaran151	however it throws a Java IO file exception
18:55	Licenser	is there something like a default case for multi methods?
18:58	mebaran151	still can't find them
18:58	mebaran151	I just have 3 simple clj files in test
18:58	mebaran151	changed them all to have flat namespaces without the com.bebop prefix, but lein test can't find 'em
19:13	hoeck	Licenser: yes, :default option in defmulti, defaults to :default, e.g. (defmethod foo :default [] ...)
19:14	Licenser	hoeck: so whatever I pass if nothing else matches :default will be called? Nice :D thank you hoeck
19:15	hoeck	Licenser: exactly
19:15	Licenser	hamza: way thank you!
19:49	polypus	is there a good writeup anywhere on deftype. i'm especially interested in how it fits into or is used in conjunction with derive and the hierarchy system. any pointers?
20:25	hoeck	polypus: have you seen http://www.assembla.com/wiki/show/clojure/Datatypes ?
20:30	mebaran151	I have a weird issue: I have to mutually reliant clj files
20:30	mebaran151	*two
20:31	mebaran151	but it seems one can't see the globals that it uses from the other
20:45	arohner	what do you mean by mutually reliant?
20:45	arohner	nm, he left
20:46	ohpauleez	arohner: I bet he meant he has circular dependencies
20:46	arohner	yeah, that's what I suspected
21:12	mebaran151	I have two mutually reliant namespaces
21:12	mebaran151	while I somehow get them to load at the repl
21:12	mebaran151	all my compiles fail with various var not found messages
21:14	hiredman	don't do that
21:15	mebaran151	I wanted to split out the indexing from the my main wrapping code
21:15	hiredman	so?
21:15	hiredman	don't create cyclic dependencies
21:16	mebaran151	well I just need one var from the main namespace neo
21:16	Chousuke	if you just want to split the code, you can use load to load plain files.
21:16	mebaran151	is there anyway just to copy the var
21:16	mebaran151	otherwise I can always just cut and paste it back together
21:18	mebaran151	are there no possible declare hacks?
22:22	mebaran151	ah well, I just refactored so as to avoid the circular dependencies
22:22	chouser	mebaran151: good job!
22:23	mebaran151	but there's no way to have circularly dependent clj files for the future?
22:24	chouser	not that I know of. Does it really seem like a good thing to you?
22:40	mebaran151	it was just one global variable that would have been nice to have had access to within both
22:41	mebaran151	and also I ended up having to cut and paste one small definition that probably should get moved to a utils anyway
22:47	danlarkin	I want to convert a clojure.lang.Ratio to a BigInteger, do I have to do something like this, (.divide (.numerator 9/4) (.denominator 9/4))?
22:53	piccolino	Is that gonna be an integer?
22:54	danlarkin	it's a BigInteger
22:54	technomancy	danlarkin: will (int my-ratio) cause nasty overflow? it works fine for small values
22:55	technomancy	to answer my own question: yes, it overflows
22:55	danlarkin	technomancy: values will be larger than an int can hold :(
22:55	ikitat	,(.decimalValue 999999999999999/2)
22:55	clojurebot	499999999999999.5M
22:56	chouser	'int' means primitive int
22:58	ikitat	,(type (.toBigInteger (.decimalValue 9/4)))
22:58	clojurebot	java.math.BigInteger
22:58	technomancy	handy
22:58	danlarkin	Hm!
23:00	ikitat	or .toBigIntegerExact which will throw an ArithmeticException on ratios that result in remainders
23:00	technomancy	\
23:03	danlarkin	ikitat: thanks, .toBigInteger on the .decimalValue is what I'll use
23:05	ikitat	,(bigint (bigdec 9/4))
23:05	clojurebot	2
23:05	ikitat	a bit nicer
23:06	ikitat	,(bigint 9/4)
23:06	clojurebot	2
23:06	ikitat	haha... jackpot
23:06	danlarkin	hey now that's more like it