#clojure – 2009-08-01

2009-08-01

00:31	iBong	(for [x (range 4) y (range 4)] (print (+ x y)))
08:08	dysinger	monin
08:08	rhickey	hey
08:09	lbj	Hey guys - Ive imported ServletFileUpload into my namespace and I'm having a problem calling a method. Is there a way to list all methods imported from that namespace, ie ServletFileUpload/* and possibly see which args they take?
08:15	dysinger	can you pastie the error / code ?
08:16	lbj	You dont need it to tell me how to avoid hitting the javadocs everytime I have a question about a method :)
08:17	dysinger	That's what javadocs are for :)
08:17	dysinger	You said you were "having a problem calling a method"
08:23	dysinger	lbj: are you using emacs / slime ?
08:30	dysinger	lbj my guess is that you are used to an IDE w/ refletion code completion pop ups
08:31	dysinger	some of the newer ide plugins for clojure have that
08:31	dysinger	I just hit C-c C-d C-d in emacs / slime to jump to the javadocs if I need it.
08:32	dysinger	The intellij guy who is writing the clojure plugin showed it to us at the june meetup
08:32	dysinger	looks pretty slick but i don't think I could ever leave emacs for lisp development
08:33	dysinger	The editor still kicks arse all over the IDEs
08:36	lbj	Sorry, I was afk :)
08:37	lbj	Yes I think I'll be hard to drag away from Emacs as well. I think kotarak succeeded in doing Java reflections for his VimClojure
08:37	lbj	...and if Vim can do it ...
08:37	lbj	@ dysinger
09:48	dysinger	Is there any code in contrib to reflect java object methods ("like poor-mans java version of find doc") ?
09:48	dysinger	I didn't see any
09:48	dysinger	was going to write one
09:49	Chouser	repl-utils/show ?
09:49	dysinger	dogh guess I didn't look hard
09:51	dysinger	there we go :)
09:51	dysinger	thanks Chouser
09:51	dysinger	lbj: there you go ^
09:52	rhickey	anyone try new new yet? the latest infers the types
10:17	Chouser	rhickey: I'm getting NoSuchMethodError: clojure.lang.RestFn.<init>(I)V
10:17	Chouser	still trying to find the specific cause
10:18	lbj	dysinger, Chouser: Thanks
10:18	rhickey	Chouser: getting it with the very latest?
10:19	rhickey	chouser: did you ant clean contrib? I had that problem before I did
10:20	rhickey	the latest new code builds and tests cleanly the latest contrib
10:20	Chouser	that's probably it -- just a sec
10:21	rhickey	Mark Tarver throws in the towel on Qi - "There is no such thing as free software. That’s the fallacy. There is only software that is paid for by somebody else."
10:21	Chouser	:-(
10:21	rhickey	http://groups.google.com/group/Qilang/browse_frm/thread/592773c562017d87
10:23	Chouser	ant clean in contrib fixed it.
10:24	Chouser	so now if I hint any args on a new's method, all the unhinted are assumed to be Object or something?
10:24	rhickey	Chouser: right, no hint is Object, no hints at all tries to find a single method in your supers to override
10:25	rhickey	methods overloaded w/same arity in supers require full matching type spec
10:26	rhickey	in the no hints, override found, you'll get the exact signature from the super
10:27	rhickey	http://www.lambdassociates.org/blog/prolegomena(1).htm
10:29	drewr	rhickey: thank you for paying for clojure
10:29	Chouser	well this is beautiful. the proxy form in lazy-xml has become a new that is smallar and undoubtedly more efficient
10:30	rhickey	I swapped out future-call and promise with new new
10:30	rhickey	still to go: efficient self-calls and volatile
10:34	rhickey	drewr: the bill is in the mail :)
10:35	Mark_Addleman	i see a weird interaction between a (println) statement and a very large sequence...
10:36	Mark_Addleman	(deftest test-lots-of-times
10:36	Mark_Addleman	(let [s (repeatedly #(java.util.Date. (long 0)))]
10:36	Mark_Addleman	(dorun
10:36	Mark_Addleman	(take 10000000 s))
10:36	Mark_Addleman	#_(println "done")))
10:36	Mark_Addleman	this code runs fine
10:36	Mark_Addleman	but when i remove the comment, i get an out of memory error (my JVM has 32m of heap)
10:37	Mark_Addleman	why would the presence of println cause clojure to retain memory?
10:41	opqdonut	i'd guess because s doesn't leave scope as quickly then
10:42	lbj	I'm looking forward to the answer rhickey, looks like unexpected behaviour :)
10:42	opqdonut	hmm, but isn't take lazy?
10:42	lbj	Hence the dorun
10:42	opqdonut	ah, dorun
10:42	opqdonut	yes
10:42	Mark_Addleman	just ran another test:
10:42	Mark_Addleman	(deftest test-lots-of-times
10:42	Mark_Addleman	(let [s (repeatedly #(java.util.Date. (long 0)))]
10:42	Mark_Addleman	(dorun
10:42	Mark_Addleman	(count (take 10000000 s)))
10:42	Mark_Addleman	#_(println "done")))
10:43	drewr	lisppaste8: url
10:43	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
10:43	Chouser	Mark_Addleman: please don't paste multiple lines here
10:43	Mark_Addleman	this also explodes with OOM. i'd expect count to be a simple accumulator and not hold onto the head
10:43	drewr	Mark_Addleman: ^^
10:43	Mark_Addleman	ah, sorry
10:43	lbj	Chouser: Is it really a problem when were speaking 5 - 6 lines?
10:43	lbj	I think thats an easier read than hunting links, personally
10:44	lisppaste8	Mark_Addleman pasted "unexpected out of memory" at http://paste.lisp.org/display/84564
10:45	lisppaste8	Mark_Addleman pasted "untitled" at http://paste.lisp.org/display/84567
10:46	lisppaste8	Mark_Addleman annotated #84567 "untitled" at http://paste.lisp.org/display/84567#1
10:49	Mark_Addleman	if i'm not doing something stupid with the code, i'll file a bug report. what's the process for that?
10:52	lisppaste8	Mark_Addleman pasted "untitled" at http://paste.lisp.org/display/84568
10:53	lisppaste8	Mark_Addleman annotated #84568 "untitled" at http://paste.lisp.org/display/84568#1
10:54	lisppaste8	Mark_Addleman annotated #84568 "untitled" at http://paste.lisp.org/display/84568#2
10:54	lisppaste8	Mark_Addleman annotated #84568 "untitled" at http://paste.lisp.org/display/84568#3
10:55	lisppaste8	Mark_Addleman annotated #84568 "untitled" at http://paste.lisp.org/display/84568#4
10:55	lisppaste8	Mark_Addleman annotated #84568 "untitled" at http://paste.lisp.org/display/84568#5
10:56	rhickey	Mark_Addleman: locals are cleared only on tail calls
10:56	rhickey	Mark_Addleman: locals are cleared only on tail calls
10:57	Mark_Addleman	rhickey: i don't follow. isn't the the local lazy? i understand why it would retain the latest value from the seq, but why more than that?
10:58	rhickey	following the count cal with print means local s is held until the print call
10:58	lbj	Ah ok, makes sense
10:58	rhickey	dorun walks while local s holds head
10:59	rhickey	realizing entire list
10:59	rhickey	lazy != ephemeral
10:59	Mark_Addleman	according to the docs, dorun does not retain the head. doall does
11:00	opqdonut	right
11:00	opqdonut	it's s that retains the head
11:00	Mark_Addleman	ah! alright
11:00	opqdonut	it has to be held on to in case the println needs it
11:00	Mark_Addleman	thanks for that
11:00	rhickey	this has nothing to do with dorun/doall holding the head, local s is holding the head
11:02	Mark_Addleman	ok, so what i want is a generator. i want to return an infinite number of dates (where each date is one second later than the previous one). i don't need to retain the head.
11:02	Chouser	I'm certainly sympathetic with Traver's frustration with his own project, but I find his broader conclusions uncompelling. I hope he finds the personal satisfaction he's seeking.
11:03	Mark_Addleman	i know how to write a function that does that, but i want that function to play well with the seq library... that's where i went awry
11:04	Chouser	java.util.Dates?
11:05	Mark_Addleman	yes
11:05	Chouser	if you use something like 'iterate', you shouldn't have to worry about cleared locals, tail calls, etc.
11:07	Mark_Addleman	ok... i've seen the iterate function but i haven't wrapped my head around how to use it
11:08	Chouser	,(take 3 (iterate #(let [d (.clone %)] (.setSeconds d (inc (.getSeconds d))) d) (java.util.Date.)))
11:08	clojurebot	(#<Date Sat Aug 01 08:11:29 PDT 2009> #<Date Sat Aug 01 08:11:30 PDT 2009> #<Date Sat Aug 01 08:11:31 PDT 2009>)
11:09	Mark_Addleman	i see. i was using a true stateful function with a ref to store my counter (thinking there had to be a functional solution).
11:09	Mark_Addleman	thanks for the pointer
11:12	lbj	By the by - Anyone know of a simple thin interface to unix syslog from Java ?
11:18	dysinger	lbj to write or read ?
11:18	Mark_Addleman	you want to post to syslog?
11:18	dysinger	log4j has a syslog adapter
11:18	dysinger	but thats write only
11:18	lbj	To write
11:18	lbj	I'm looking at syslog4j atm
11:19	dysinger	that's why I'm using log4j under commons logging
11:19	lbj	Just wondering if one had tried something and came back with a good report
11:19	dysinger	is because I can pipe it to syslog for production
11:19	dysinger	I have not wired it up yet but that's the plan
11:19	lbj	Ok
11:20	dysinger	no other popular loggers can pipe to console in dev & syslog in production
11:20	dysinger	that I know of
11:20	lbj	So where are you piping it now?
11:21	lbj	I'll take a loo at log4j
11:21	lbj	syslog4j looks very simple too though
11:21	Mark_Addleman	depending on what you're trying to do, log4j can be too much candy for a nickle
11:21	Chouser	lbj: clojure.contrb.logging ?
11:22	lbj	Oh you know I never look in contrib :)
11:22	Chouser	that just wraps other libs though, like log4j. I think.
11:23	lbj	Ah ok, Ill check it out
11:24	lbj	Google Code still comes up as the first hit when I search for Clojure contrib, consider shutting it down ?
11:27	lbj	(defmacro log4j-logging) is a macro which takes no arguments and returns a struct - why is that a macro ?
11:36	lbj	Chouser: I sense you had a hand in this :)
11:41	bairespace	I keep seeing the suggestion that clojure-in-clojure might be adapted to run on the objective C runtime
11:41	bairespace	& I'm wondering: could a similar thing be done wrt the emacs runtime? or wrt other lisps?
11:41	Chouser	lbj: logging? not at all.
11:42	Chouser	bairespace: in order to run clojure inside emacs? or emacs on the iPhone?
11:44	bairespace	chouser: clojure inside emacs
11:50	lbj	Back up the iPhone - Somebody found a way to execute Clojure on it ?
11:51	lbj	bairespace: http://github.com/technomancy/clojure-mode/tree/master <-- Technomancy has an install function which will pull down all dependencies and show you an example of .emacs
11:51	bairespace	Chouser: clojure inside emacs.
11:52	bairespace	lbj: thanks.
11:52	Chouser	bairespace: an interesting idea. don't see why not.
11:52	Chouser	bairespace: it wouldn't be full Clojure of course -- not threads, etc. but it might be possible for some subset of clojure code to be compiled to elisp
11:54	lbj	back to the iphone.... :)
11:54	bairespace	I was thinking there might be some other snag: slowness, maybe. Luke Gorrie's distel did something similar for a subset of erlang, I think.
11:56	lbj	dysinger: I dont see syslog as an output option for log4j, Windows NT Log Service is supported however
12:14	bairespace	Chouser: only need to call or create elisp code from Clojure, really. Especially if it was convenient to use more than one such adaptation of Clojure in the same program--with Clojurescript, say.
12:15	bairespace	got to go...
12:19	Mark_Addleman	lbj: http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/net/SyslogAppender.html
12:25	lbj	Mark_Addleman: Thanks
12:44	lbj	Let me just see if I got this straight. If I wrap my functions in a log macro, which then uses send-off to start some logging service, then send-off it self will regulate how many threads to launch at a time so that this does not destroy overall performance of the app ? Or do I need to be more strict with my ressources?
12:46	Chousuke	lbj: agents have a thread pool
12:46	Chousuke	so it won't spawn new threads for every send-off
12:53	lbj	So I wont need to be more strict, but also be prepared for some delay. Sounds good
14:57	alrex021	When using for example :only keyword when importing specific function from another namespace, why are square brackets used? e.g. (use '[clojure.contrib.math :only (round)])
14:57	alrex021	trying to get my head around this
14:58	Chousuke	it's a list of specific functions to import
14:58	Chousuke	in your case, a list with one item
14:58	alrex021	I though lists where represented with () and not like vectors []
14:58	alrex021	I mean
14:58	Chousuke	ah, wait, I misread
14:59	alrex021	sorry I see square brakets before the use '\
14:59	alrex021	if no keywords, then it looks like (use 'clojure.balabla.bla)
14:59	Chousuke	yeah
14:59	Chousuke	the plain symbol is just a shortcut
15:00	Chousuke	the vector specifies a library and its options.
15:00	alrex021	oh I see, so it has to be a vector in those cases
15:00	Chousuke	yeah.
15:01	Chousuke	(use 'foo.bar) is short for (use '[foo.bar])
15:01	Chousuke	but it doesn't work if you have :as or :only etc.
15:01	Chousuke	so you need the vector.
15:02	Chousuke	there was some talk about improving the import syntax, but I don't think anyone did anything :/
15:07	alrex021	yup, confusing for new comer to the language like myself
15:09	alrex021	I understand shortcuts like #(..... %) for fn [] body ....but no so much the one above :)
15:10	Chousuke	the ns macro syntax is not too complex after you get it... but it isn't that well documented either.
15:10	Chousuke	the documentation is kind of scattered
15:11	alrex021	I'm reading the clojure book for the second tome
15:11	alrex021	time...things ae making more sense this time around
15:11	Chousuke	heh
15:12	Chousuke	I suppose it's true that you need to read a book at least twice to make any sense out of it.
15:12	alrex021	I tell you what, first time coming to any lisp dialect, what a mind f***
15:13	Chousuke	heh
15:13	Chousuke	I think it's the functional programming that gets people at first.
15:13	Chousuke	and the parentheses, until they understand it's really no worse a syntax than reserved words and curly brackets
15:13	alrex021	that book maid very little sense first time, makes you feel a bit helpless especially having over a decade in programming behind me....well oop and less fp
15:15	alrex021	but starting to really enjoy it now... I have a strong web dev background so I see myself joining the web framework dev efforts in clojure space
15:15	alrex021	if I get that far ;)
15:18	alrex021	u r abs right. it is the fp that get ppl
15:25	hserus	in my case, im currently stumbling at the lazy concepts :)
15:25	hserus	got a quick question on that, is there a pattern on when to evaluate a lazy sequence?
15:27	hoeck	hserus: what do you mean by "evaluating"?
15:29	hserus	i mean realizing a lazy sequence (basically doing a dorun)
15:30	hserus	what do you usually refer this as?
15:30	hoeck	maybe "forcing" a lazy sequence
15:31	hoeck	only when the computation itself has side effects
15:32	hoeck	and you want those side effects now
15:32	hserus	right, when i want to test a function that returns a lazy sequence (and since that is the default, i guess in most cases) i end up forcing the lazy sequence
15:34	hoeck	yeah, and printing (e.g. at the repl) always forces the lazy sequence
15:34	hserus	yup, learnt is the hard way.. i was wondering why my unit tests fail, but the same code works on repl
15:39	Chousuke	sometimes you want to force stricness so that you don't get "too lazy"
15:39	Chousuke	strictness*
15:40	Chousuke	I mean, there are situations where you end up generating so many thunks that it blows the stack.
15:40	hserus	currently, for my web app, an example where im doing this is just before persistence of my entities..
15:40	hserus	is that correct?
15:41	Chousuke	I can't say.
15:41	Chousuke	but if it works, it's probably okay :P
15:41	hserus	hehe
15:42	Chousuke	forcing strictness only gets you potentially suboptimal performance if you end up doing it in places where you could afford to be lazy.
15:43	hserus	my doubts has been around unit testing, so is it fine that i have to force sequences in my tests for functions that return lazy sequences?
15:47	hoeck	only if the lazy-seq returning functions, for some good reason, have side effects you want to test
15:49	lbj	How is arity dispatching handled when in a macro ?
15:50	hoeck	hserus: if you only compare the results with a literal list, like (= '(1 2 3) (my-fn)), then you don't have to (doall (my-fn)), = does this when necessary
15:51	hserus	hoeck: even when my-fn returns a lazy seq?
15:52	hoeck	lbj: at compile time, the compiler counts the expressions passed to the macro
15:53	lbj	hoeck, I meant practically :) I would have imagined something like this to work (defmacro tst ([x] `(tst 5 ~x)) ([x y] `(+ ~x ~y))), but no dice
15:57	hoeck	lbj: it works, try (macroexpand-1 '(tst 1))
15:58	lbj	Interesting - It expands correctly in both cases, but throws a 'new instance' exception when run... ?!
15:58	hoeck	hserus: '=' will just evaluate as much elements as it needs to compute a result
15:59	lbj	user> (macroexpand-1 '(tst 1 2))
15:59	lbj	(clojure.core/+ 1 2)
15:59	lbj	How can this blow up with an exception ?
16:00	lbj	Argh, my bad, misplaced symbol
16:00	lbj	sorry
16:00	danlarkin	,(let [s "/\\\""] (= (name (symbol s)) s))
16:00	clojurebot	false
16:00	danlarkin	is that a bug?
16:07	hoeck	,(name 'a/b)
16:07	clojurebot	"b"
16:08	danlarkin	d'oh
16:08	danlarkin	it's thinking it's the namespace I guess?
16:08	iBong	any idea why I get a "function import is void" error when trying to eval a source file buffer, but it runs fine when pasted into the REPL?
16:11	hoeck	danlarkin: well, "/" is at reserved for namespace-name separation, so it makes no sense to use it as a symbol character except for divide
16:11	danlarkin	Hmmm
16:12	hoeck	danlarkin: so symbol just reads "/bla" as symbol bla without a namespace
16:12	danlarkin	hoeck: ah yes, of course, you're right
16:13	hoeck	danlarkin: mhhh, only the name function returns the correct name, str returns "/bla"
16:14	danlarkin	yeah, now I have to decide it I should use name or subs str
16:15	hoeck	danlarkin: I guess one should be careful when generating symbols from strings, using symbol, the reader is more strict and doesn't read symbols like '/bla
16:16	danlarkin	well this is just covering corner cases in my tests
16:27	falkor	hi, I am trying clojure and am having a 110% newbie problem...
16:30	hserus	falkor: what is it?
17:12	l0st3d	,(do (def t 0) (binding [t 1] (println t)))
17:12	clojurebot	DENIED
17:15	l0st3d	Hi, I'm learning clojure atm - correct me, but shouldn't (def t 0) (binding [t 1] (println t)) print "1" ? - it prints "0" on my machine
17:17	fffej	lost3d: it prints 1 for me if that helps
17:17	danlarkin	l0st3d: prints 1 for me too
17:17	fffej	perhaps try updating to the latest version?
17:17	l0st3d	ok thanks guys
17:21	fffej	If I've got a pattern like (doseq [x (iterate f 0)] body) is there any way to interupt the body of the doseq? At the moment I'm throwing an exception to get out of it which feels completely wrong (it's for a GUI and the user can interupt (by means of setting an atom) the process
17:31	hoeck	fffej: you could wrap the seq generation in a take-while
17:32	fffej	hoeck: thanks, that sounds perfect
17:32	hoeck	fffej: (doseq [x (take-while (fn [_] @abort) (iterate f 0))] ..)
17:33	fffej	thanks, works a treat
17:40	lisppaste8	iBong pasted "let abuse?" at http://paste.lisp.org/display/84590
17:40	lbj	I just tried to let a servlet accept an upload of 250Mb and according to my logging the upload went fine, and the file landed remotely as it should, but afterwards Firefox crashed. Any idea why ?
17:41	iBong	I find myself writing lots of code like this, it seems somehow "imperative", just wondering if it's a bad habit or if its just a question of style (I find these kind of let blocks make my code more readable)
17:43	fffej	iBong: I think it's only let abuse if there's side effects, I use let a lot too because (as you say) it makes it more readable
17:43	iBong	no side-effects
17:43	fffej	so no abuse (in my limited experience!)
17:43	iBong	that's good to hear then
17:45	fffej	what is "new new"?
17:46	rhickey	fffej: like proxy but faster
17:47	fffej	rhickey: sounds good!
18:07	dysinger	am excited about our clojure team build out ;)
18:08	Anniepoo	is there a good reason, given 'don't wrap java unnecessarily', for shell-out?
18:14	dysinger	"new new" sounds like a character from Teletubbies
18:16	Anniepoo	Rich Hickey secretly has a TV in his tummy - pass it on
18:17	rhickey	dysinger: cool - how many devs are you up to?
18:19	dysinger	4 and maybe 5 this month
18:20	rhickey	awesome
18:20	rhickey	finding good people?
18:20	dysinger	they are lined up
18:20	dysinger	I just had to mention it on twitter
18:20	dysinger	everybody is people in here that you know
18:21	Anniepoo	having a meetup?
18:21	dysinger	s/everybody is/every person is
18:21	dysinger	whatever - you got me
18:22	dysinger	Anniepoo: no building a team of devs to work on clojure projects.
18:22	Anniepoo	ah, cool
18:23	rhickey	start of some docs for new new: https://www.assembla.com/wiki/show/clojure/New_new
18:29	mattrepl	dysinger: sent you a pm re: clojure jobs
18:33	tomoj	there are jobs for clojure? O_o
18:34	chouser_	,(map #{1 3 4 5 6} #{1 2 3 5 6 7})
18:34	clojurebot	(1 nil 3 5 6 nil)
18:36	rhickey	interesting visit by chouser?
19:19	pokey9	what is sqrt in clojure?
19:24	Anniepoo	you can use the java Math/sqrt
19:25	Anniepoo	or the math API in clojure.contrib
19:25	Anniepoo	http://code.google.com/p/clojure-contrib/wiki/MathApiDoc
19:26	Anniepoo	if you use the latter you'll have to do (:use clojure.contrib.math) in your ns at the top of your file
19:27	Anniepoo	ns is kinda like java's package / import
19:27	Anniepoo	do you know Java?
19:30	dysinger	Anniepoo: yes
19:30	dysinger	on both
19:30	dysinger	well sort of - it's not a direct mapping
19:31	dysinger	but close
19:31	Anniepoo	yes, I'm assuming he's a beginner to Clojure, and offering a useful metaphor
19:32	dysinger	whos "he" ?
19:33	Anniepoo	pokey9
19:33	dysinger	Oh I got turned around - I thought you were asking not commenting.
19:34	Anniepoo	(I'm also assuming pokey9 is a man, rather than a woman, it seems the Bayesian thing to do, but
19:34	Anniepoo	I'm probably not being a good feminist by doing it)
19:35	Anniepoo	16:19] <pokey9> what is sqrt in clojure?
19:35	pokey9	Anniepoo, i have CLisp installed in my .emacs as well, and like to use the slime command for lisp interaction with that
19:35	pokey9	but i put the Clojure code in my .emacs file so now when i do M-x slime it does Clojure REPL
19:36	pokey9	how do i differentiate so i can do CLisp sometimes and Clj others?
19:36	Anniepoo	dunno, somebody else will have to address that, I'm an IntelliJ user
19:36	dysinger	There is an alternate way of starting slime that lets you pick
19:36	dysinger	I forget what it is - one sec
19:39	dysinger	pokey9: it's C-u M-x slime and it will ask you which impl to use
19:40	pokey9	dysinger, thanks. My alternative was going to be to comment out whichever one i didnt want to use in the .emacs file every time. So this is an improvement :)
19:40	dysinger	If you search cliki wiki for slime there is a bunch of tips
19:42	JAS415	clojure is nice for doing stuff
19:57	prospero_	if I want to have one thread sleep until another has completed a task, do I need to use java concurrency primitives?
20:06	Anniepoo	prospero, do you mind my asking why you want to use Java threads in the first place?
20:07	Anniepoo	One of Clojure's advantages is that it has better concurrancy mechanisms
20:07	JAS415	what if you have to do something that is timed
20:07	JAS415	like i want my doodad to update every 5 minutes
20:08	Anniepoo	I think you'd use a Java timer, but that's NOT an authoritative answer, I'm kind of a beginner myself
20:08	prospero_	Anniepoo: I'm working with OpenGL
20:08	Anniepoo	ah, cool
20:09	Anniepoo	I'm a graphics person too
20:09	prospero_	and it needs to be on a particular thread
20:09	Anniepoo	sure
20:09	Anniepoo	swing's same way
20:09	prospero_	right now I'm working with GPGPU
20:09	Anniepoo	ooh, sweet
20:09	prospero_	and I'd like to be able to treat it as thread-agnostic, even though it isn't
20:10	Anniepoo	sure
20:10	prospero_	so the best way I can figure is wrap up the call in a macro which acquires a semaphore, pushes off a request to the render thread, and then releases the semaphore at the end of the render call
20:10	Anniepoo	ok, then yes, just use the Java interop like normal java
20:10	prospero_	I just wasn't sure if there was a more clojure-ish way to do it
20:11	Anniepoo	check out ref's
20:11	Anniepoo	that's what that mechanism is for
20:11	Anniepoo	do you have Stuart Halloway's book?
20:15	prospero_	yes
20:16	prospero_	STM seems a little bit of a weird fit for the problem, even if it could pull it off
20:56	rabidsnail	My script runs fine in the repl, but when I try to load it using clojure.main or clojure.lang.Script, I get a java.lang.ExceptionInitializerError.
20:58	rabidsnail	here's the backtrace: http://paste.lisp.org/display/84597
21:08	mattrepl	rabidsnail, can you paste your script?
21:09	mattrepl	it looks like you're attempting to load a properties file that isn't on your classpath
21:10	rabidsnail	http://paste.lisp.org/display/84599
21:10	rabidsnail	I just downloaded clojure.jar again and now it works
21:12	JAS415	neat
21:30	Anniepoo	strange
21:30	Anniepoo	,(sh "notepad.exe")
21:30	clojurebot	java.lang.Exception: Unable to resolve symbol: sh in this context
21:31	Anniepoo	,(use 'clojure.contrib.shell-out)
21:31	clojurebot	nil
21:32	Anniepoo	,(sh "notepad.exe")
21:32	clojurebot	java.security.AccessControlException: access denied (java.io.FilePermission <<ALL FILES>> execute)
21:32	Anniepoo	hmmm
21:32	Anniepoo	I'm trying to launch an external process from Clojure, via the sh
21:33	Anniepoo	I've also tried using java.lang.Runtime
21:34	Anniepoo	on my (windows XP) machine if I (sh "notepad.exe") it returns an empty string but no notepad window pops up
21:34	Chouser	Anniepoo: I wrote shell-out, but have tested it only on Linux.
21:35	Anniepoo	same behavior for calling Runtime#exec directly
21:37	Chouser	You asked earlier why it's worth wrapping Runtime -- for trivial cases (string in, string out) 'sh' is a much simpler API
21:37	Anniepoo	ok, I see that
21:38	Anniepoo	that was when I was 'this is a trivial thing to do
21:38	Anniepoo	now I'm still trying to do it
21:38	Chouser	heh
21:41	Anniepoo	it's not the path, cause it does what you expect if you say (sh "notarealfile.exe")
21:41	Anniepoo	in my repl it returns ""
21:42	Anniepoo	in my code it's just not launching, either photoshop or notepad
21:42	Anniepoo	I'd use linux but I need to use projectors ;c)
21:45	mebaran151	Anniepoo, projectors?
21:46	Anniepoo	sorry, inside joke - Rich Hickey came to a special baclojure meeting during JavaOne, they
21:46	Anniepoo	were going to do speed talks, each person does 10 minutes. All these engineers had linux on laptops and none could get
21:47	Anniepoo	them to work with the room projector.
21:47	mebaran151	hahaha, that's pretty funny
21:47	mebaran151	the newer xorgs though don't have that problem as much, especially with xrandr
21:48	mebaran151	my coworker was so surprised when it just worked: (we'd spent an afternoon fighting jetty so we were expecting more Linux wars...)
21:48	Anniepoo	I had visions of somewhere across town a bunch of marketing flacks smoothly running presentations off windows vista
21:50	mebaran151	no no , off Mac OS X laptops with cruddy bad blitting graphics cards
21:51	JAS415	i wrote a restful api interfacing library writing library, do you think people would find that useful?
21:52	JAS415	so like, i wrote a twitter interface in a few lines of code that compiles mostly to calls to apache httpclient and oauth signpost library
21:52	mebaran151	man fighting the pomp and circumstance of bdb is beginning to get a bit tiresome: anybody know of a nice simple functional btree library
21:52	mebaran151	just for storing ordered collections
21:53	mebaran151	JAS415, sounds pretty neat: wrap it up in a JAR and tell the world!
21:53	mebaran151	(if you want a nice async http library check out xlightweb as well)
21:53	mebaran151	(I have a basic wrapping of it if you want to borrow it)
21:55	JAS415	okay, i'm just nervous because my code always works for what I use it for but never stands up to academic scrutiny
21:56	Anniepoo	ignore the academic scrutiny
21:56	mebaran151	oh people on the mailing list have been pretty chill
21:56	mebaran151	they'll even fix it for you
21:57	mebaran151	I'm probably going to split out my bdb clj bindings if anybody wants them
21:58	Anniepoo	I'm on a standards working group (groan). We have a loudmouth who tells everybody how it is and why their ideas suck
21:58	mebaran151	I'm still trying figure out a good way to integrate secondary indexes, or whether I'd might as well try to do all the joining myself
21:58	Anniepoo	one day she proposes something that is easy to test (I've forgotten what), and tries to actually write it.....
21:59	Anniepoo	after we saw her code we took her pronouncements less seriously
21:59	mebaran151	ha
21:59	mebaran151	I'm so sick of Oracle Engineering
21:59	mebaran151	Oracle should change their name to Over Engineering
22:00	mebaran151	only they would have a Factory class for a Config class that gets passed to another factory
22:02	JAS415	I dunno, maybe i'm not a team player, but I just write code so that it works and don't worry about it until it is proven to not work...
22:03	mebaran151	well it's nice to have a quick test suite
22:03	mebaran151	most useful in deployment actually: when you put the code up, run the tes suite ad make sure all the libraries got up okay
22:08	Anniepoo	nice.
22:08	Anniepoo	now I've corrupted my project file, apparently
22:08	Anniepoo	not my day
22:17	mebaran151	in eclipse?
22:20	JAS415	which is why i use emacs now
22:20	mebaran151	I'm in netbeans: I could never really stick with emacs
22:20	mebaran151	always was a vim guy
22:21	mebaran151	but now I'm spoiled by the gui goodness of netbeans
22:22	JAS415	I just really like being able to hit ctrl+alt+q and have my code indent itself
22:22	JAS415	that's actually the only thing i missed when i was trying to use eclipse or emacs
22:22	mebaran151	you can use alt-r with clojure plugin
22:22	mebaran151	ctrl a and alt r
22:23	mebaran151	and shotgun line up
22:23	JAS415	ah really?
22:23	JAS415	i guess the other thing was i kept printing things that were longer than the eclipse repl would handle
22:23	JAS415	by emacs above i meant to say netbeans*
22:24	JAS415	anyway i normally assume that my failure to use a tool properly is my fault rather than the IDE's
22:24	JAS415	you know what you know, as they say
22:25	mebaran151	oh there's an option somewhere for that
22:25	mebaran151	but usually, when I want something printed
22:25	mebaran151	I want ALL OF IT (grrr)
22:26	JAS415	well in eclipse I would generally crash eclipse completely
22:26	JAS415	I would tell it to grab some xml output and parse it to a zip
22:27	mebaran151	eclipse lieks to eat all of my RAM
22:27	mebaran151	for no apparent reason
22:27	JAS415	it would print the first 100 lines or so and then die horribly
22:27	mebaran151	so the clojure plugin on eclipse is not ready for the big time yet?
22:27	JAS415	not if you want to do repl development
22:28	JAS415	which is really my style
22:28	JAS415	if you just want to build projects it is fantastic honestly
22:29	mebaran151	I like to throw some code at the repl every now and again
22:29	JAS415	nice simple creation of directories and sub directories and stuff
22:29	mebaran151	I'm glad they got ... file management working :P
22:29	JAS415	i kind of have a weird background i guess
22:29	JAS415	for work I use common lisp and we don't have a full IDE for it
22:29	JAS415	it is old and broken in horrible ways
22:29	JAS415	so I do a lot of repl debugging and print statements
22:30	mebaran151	no emacs?
22:30	JAS415	to figure out what the hell is happening
22:30	JAS415	i have emacs but no slime
22:30	mebaran151	oh
22:30	mebaran151	pity
22:30	JAS415	so i'm copy/pasting
22:30	mebaran151	I never did get into using a breakpointer either
22:30	mebaran151	I do throw debuging
22:30	JAS415	yeah is just because we use goldhill common lisp which is a bit before slime
22:30	mebaran151	as in, let's see how far we can get before we throw
22:31	JAS415	yeah the problem is that sometimes your customers figure out a clever way to wreck your code with throw debugging
22:31	JAS415	just because people are inherently baysian and likely to follow the same gui paths that they did before
22:31	mebaran151	usually before I release, I go through and destroy all my throws
22:32	JAS415	so you get a new human and they take a different path and you find different errrors
22:33	mebaran151	that's why you got reduce the number of humans :)
22:33	JAS415	that's right, that's why we gotta fight the marketing and sales guys tooth and nail
22:33	mebaran151	only in Javaland would the standard library have a full fledged sql library but no simple library for basic sorted hash btree persistence
22:36	JAS415	i'm not sure i know what hash btree persistence is, but I adapted the 'memoize' function in clojure.core to extend to printing out hashtables when they get updated
22:36	JAS415	so you you get a function that is cached between user sessions
22:37	JAS415	and obviously there are limitations as a lot of things don't have printable representations
22:39	JAS415	anyway i'm looking for a better way to do it as it is annoying to have to write the whole map out to file every time it gets updated
22:41	iBong	what's the standard way to remove a seq of keys from a map?
22:43	gko	dissoc
22:43	hiredman	,(apply dissoc {:foo 1 :bar 2 :a 3 :c 4} [:a :c])
22:43	clojurebot	{:foo 1, :bar 2}
22:43	hiredman	,(reduce dissoc {:foo 1 :bar 2 :a 3 :c 4} [:a :c])
22:43	clojurebot	{:foo 1, :bar 2}
22:44	mebaran151	JAS415, I was just saying a dictionary btree
22:44	mebaran151	something like bdb where you store keys and values, without the 20 thousand extra classes to make the whole task as difficult as possible
22:46	mebaran151	and you would rewrite the whole structure on updates
22:49	mebaran151	*wouldn't rewrite
22:51	JAS415	mebaran, after much googling i have figured out what a dictionary btree is :-)
22:51	JAS415	you'll have to excuse my ignorance as my training is philosophy :-P
22:51	mebaran151	oh me too actually
22:52	mebaran151	tried to open a Proverbial Philosophy Store, and that just Didn't Work Out (tm)
22:52	JAS415	haha
22:53	JAS415	I've been told that philosophy is a major with no practical application but computer science seems to fit it just fine...
22:53	mebaran151	yep, pretty easy transition
22:54	JAS415	i dunno, what is cs except math and language
22:55	mebaran151	not even as much pure math as there should be...
22:57	Anniepoo	ok, I know i have to add the source and the output paths to my classpath for the compile statement to work
22:57	JAS415	knowing is half the battle
22:58	JAS415	i think that the other half is figuring out how to configure a classpath
22:58	Anniepoo	but if my file is namespace edu.uh.foo located in src/edu/uh/foo then will I add the foo directory or the
22:59	Anniepoo	src directory?
22:59	JAS415	i think you would add edu
22:59	mebaran151	the directory above all those think
22:59	Anniepoo	I freaking corrupted my intellij project file
22:59	mebaran151	did you have an git or hg version backup?
22:59	mebaran151	it is cases like this where recloning is the one true way towards Enlightenment
23:00	Anniepoo	no, I'm working on this alone so I don't have a recent backup
23:01	JAS415	well if you look at like a jar file
23:01	JAS415	you'll see that its by subdirectories
23:02	JAS415	so like the namespace me.apibuilder.foo would be me/apibuilder/foo.clj
23:02	mebaran151	that sounds about right
23:02	Anniepoo	ok, then hang on
23:05	JAS415	so for example the classpath to contrib jar for me is: /clojure/clojure-contrib/clojure-contrib.jar which means that java starts looking inside the 'jar' file (which is a trumped up tar file)
23:05	lisppaste8	Anniepoo pasted "say what?" at http://paste.lisp.org/display/84605
23:05	JAS415	so i look inside the jar
23:05	JAS415	and i see path
23:06	JAS415	clojure/contrib/*.clj
23:06	Anniepoo	yes, I understand java jar files
23:06	clojurebot	☕
23:06	JAS415	yeah i didn't when i started this stuff
23:06	Anniepoo	but I'm utterly baffled, when I compile, I throw this exception
23:07	Anniepoo	what this rather unremarkable function has to do with ANYTHING is beyond me
23:07	JAS415	that is saying that the path doesn't exist
23:07	Anniepoo	which path?
23:07	mebaran151	hey cemerick
23:08	cemerick	evening :-)
23:08	Anniepoo	I understand "the path specified" doesn't exist
23:08	mebaran151	the ExceptionInitializer errors in Clojure are a little nasty
23:09	Anniepoo	LOL
23:09	JAS415	photoshop-startup-directory "C:\\Program Files\\Common Files\\Adobe\\Startup Scripts CS3\\Adobe Photoshop\\")
23:09	Anniepoo	how, pray tell, does it even KNOW I'm eventually turning that string into a file?
23:09	Anniepoo	(and that is indeed a valid directory)
23:10	JAS415	i think you can use forward slashes instead of escaping the \
23:10	JAS415	i kind of forget but i think thats ok
23:10	mebaran151	yep
23:10	Anniepoo	I can't say (def what-I-would-like-to-say-now "!@##$%@")???
23:10	mebaran151	WinXP is smart enough to figure out forward slashes
23:11	cark	hello all
23:11	Anniepoo	strange part is, this all was working for a while
23:11	JAS415	waitwait
23:11	JAS415	sh photoshop-exe
23:11	JAS415	that is where you use it like a path right?
23:12	jwhitlark	clojurebot: def true?
23:12	cark	,(.numerator (/ 3 2))
23:12	clojurebot	3
23:12	cark	is there a core function for this ?
23:12	clojurebot	for is a loop...in Java
23:13	JAS415	(def photoshop-exe "C:\\Program Files\\Adobe\\Adobe Photoshop CS3\\Photoshop.exe")
23:13	JAS415	(def photoshop-start-dir "\"C:\\Program Files\\Adobe\\Adobe Photoshop CS3\\\"" )
23:13	Anniepoo	yes, but #_ on that followed by a dummy
23:13	Anniepoo	gives the same error for the dumme
23:13	JAS415	you got extra slash on photoshop start dir?
23:13	mebaran151	it actually shouldn't matter
23:13	JAS415	hum
23:13	mebaran151	the extra slash
23:13	JAS415	bummer
23:14	Anniepoo	no, I don't
23:14	Anniepoo	I have an escaped quote
23:14	Anniepoo	the whole thing is in quotes
23:14	JAS415	oooooh
23:15	Anniepoo	further, comment around the entire thing, both the
23:15	lisppaste8	Anniepoo annotated #84605 "untitled" at http://paste.lisp.org/display/84605#1
23:15	Anniepoo	I comment the whole mass out as a sanity check
23:15	JAS415	and sh just sends it to shell
23:15	Anniepoo	stick in (defn do-photoshop-script [foo] nil)
23:15	JAS415	?
23:16	Anniepoo	and I get the same thing, can't find file specified
23:17	Anniepoo	pointing at the line with my dummy replacement
23:17	JAS415	hmm
23:17	JAS415	what line is it then?
23:18	lisppaste8	Anniepoo annotated #84605 "untitled" at http://paste.lisp.org/display/84605#2
23:18	Anniepoo	35 for the one with the dummy func
23:18	Chouser	so I've got this nested vector dumped out to a .clj file -- 89K worth.
23:18	Chouser	and it won't load: java.lang.ClassFormatError: Invalid method Code length 188191 in class file user$eval__952 (data.clj:8)
23:19	mebaran151	Chouser, are there any secret btree implementations for clojure that don't rely on more classes than I can shake a stick at?
23:19	Chouser	I'm a bit stumped on how to work around this.
23:19	Anniepoo	hey, is root-dir reserved for something?
23:19	Anniepoo	that smells generic
23:19	JAS415	doesn't seem so
23:20	JAS415	ser=> root-dir
23:20	JAS415	root-dir
23:20	JAS415	java.lang.Exception: Unable to resolve symbol: root-dir in this context (NO_SOURCE_FILE:0)
23:20	JAS415	user=>
23:20	mebaran151	Chouser, this probably seems incredibly silly, but have you tried splitting it up into two files or so and just conjoining both results?
23:20	Chouser	mebaran151: on-disk btree, like a simple database?
23:21	mebaran151	yeah
23:21	mebaran151	something real simple
23:21	mebaran151	I'm working BerkeleyDB right now
23:21	Anniepoo	ah!
23:21	JAS415	89k i wouldn't expect to be too big
23:21	Chouser	mebaran151: I would... yeah, bdb.
23:21	mebaran151	but I've made so many Factories, I feel like the soviet union
23:21	Anniepoo	I put (comment ....) around the entire file
23:21	Chouser	ha!
23:21	JAS415	and?
23:21	Anniepoo	followed by
23:21	Anniepoo	(defn make-floortile-file [a b] "howdy pardner")
23:21	JAS415	lol
23:21	Anniepoo	and it complains about the last line
23:22	JAS415	wow
23:22	Anniepoo	( I didn't include the ns in the comment)
23:22	cupertinochad_	Hi all. Can I ask a newbie question? I just asked it on the mailing list, but I am impatient, so I thought I'd try here ;-)
23:22	JAS415	ok
23:22	Chouser	cupertinochad_: go for it
23:22	mebaran151	Chouser, I spend half my time tryig to avoid bdb's insane attemts to reserialize things
23:22	cark	chouser : are you using the reader or is it in a function ?
23:22	mebaran151	they really want you to just use the collections api, which demands annotations and nonesuch
23:23	cupertinochad_	I have a newbie question about anonymous functions. Why does the first form below work and the second form does not?
23:23	cupertinochad_	user> ((fn [] "foo"))
23:23	cupertinochad_	"foo"
23:23	cupertinochad_	user> (#("foo"))
23:23	Chouser	cark: it's just a really big vector. (load-file "foo.clj") fails
23:23	cupertinochad_	; Evaluation aborted.
23:23	cark	chouser : why do you need to evaluate ?
23:23	mebaran151	,(#("foo"))
23:23	clojurebot	java.lang.ClassCastException: java.lang.String cannot be cast to clojure.lang.IFn
23:23	Chouser	cupertinochad_: #("foo") becomes (fn [] ("foo"))
23:23	mebaran151	ah yes
23:23	cark	chouser : you could try only loading
23:23	JAS415	cuper, because i think #( ) has special read syntax
23:23	mebaran151	Chouse beat me true it
23:23	Chouser	cark: oh! yes!
23:24	JAS415	its secrekt
23:24	JAS415	chouser: i've written and read bigger than 89k files in clojure, nothing bad happened
23:24	JAS415	is it possible that there is a nesting limit?
23:25	Chouser	it's not nested deeply 3 levels I think.
23:25	cupertinochad_	Hmm. So if I want a no-argument anonymous function that just returns a constant, how do I do that? Do I have to use (fn [] "foo")?
23:25	JAS415	that shouldn't be a problem
23:26	cark	chouser : just slurp the file and use the read function, i think that would work
23:26	JAS415	(constantly "foo")
23:26	JAS415	i think
23:26	cark	hum or directly read the stream actually
23:27	Anniepoo	ok, so I think the line that's ACTUALLY not finding it's file is
23:27	Anniepoo	(compile 'edu.uh.hhp.sl.automation.lessonPrimEditor.ui.LessonPrimPane)
23:27	Chouser	cark: indeed! perfect! thanks
23:27	JAS415	cupertinochad: ((constantly "foo"))
23:28	cupertinochad	Thank you.
23:29	cark	Chouser: cool =)
23:29	cupertinochad	Another newbie question: Where do I find the source for macros like #(expr)?
23:30	Anniepoo	ok, so I am indeed in 'source and object have to be on the classpath' hell
23:30	JAS415	oh shit, i dunno, you can download the source and look obviously...
23:30	cark	,(macroexpand '#(expr))
23:30	clojurebot	(fn* [] (expr))
23:30	JAS415	woah
23:30	JAS415	i was thinking in terms of the source of the macro itself
23:31	Chouser	cupertinochad: LispReader.java, line 548
23:31	cark	mhh reader macros are special
23:31	cark	which is a shame ! (but dont tell rhickey)
23:32	cupertinochad	Thanks again. Slime lets me hit M-. to jump to a function def, but I didn't know where to find reader macros
23:34	Chouser	FnReader for reading #(): http://tinyurl.com/l67t5h
23:35	Chouser	hiredman has started looking at rewriting that in Clojure, but I'm not sure if he plans to continue.
23:36	cupertinochad	Chouser: And thanks for the link, too!
23:37	cupertinochad	Is there an archive of the IRC channel that I can peruse?
23:37	Chouser	sure! It can be fun and enlightening to poke around in the .java sources.
23:37	Chouser	~log
23:37	clojurebot	see logs
23:37	Chouser	~logs
23:37	clojurebot	logs is http://clojure-log.n01se.net/
23:42	Anniepoo	not finding Clojure much fun right now
23:43	cark	,(.round 0.0003333M (new java.math.MathContext 4))
23:43	clojurebot	0.0003333M
23:43	cark	that seems strange
23:43	mebaran151_	Anniepoo, what's doing?
23:43	cark	how would i achieve a rounding to 4 digits ?
23:44	Anniepoo	I'm in classpath hell
23:44	Anniepoo	gimme a moment, I'm documenting it in lisppaste
23:45	mebaran151_	awww man, there ain't nothing worse than classpath wars
23:46	mebaran151_	I got into a brief argument on #java with a guy who was adamant that we should all love the classpath dearly; I disagreed
23:48	r2q2	JAS415: Are you putting your twitter library on github?
23:49	lisppaste8	Anniepoo annotated #84605 "untitled" at http://paste.lisp.org/display/84605#3
23:51	mebaran151_	if I wanted to give the world my beautiful (har har) bdb library, should I just spam the mailing list with it, or are there better packaging procedures?
23:52	JAS415	yeah i'm in the process of putting it on github
23:52	Chouser	mebaran151_: there's a thread for announcing libs, or you can just announce it. It's the best we've got so far. :-/
23:55	Anniepoo	sadly, the documentation of how it interprets the classpath is pretty lacking
23:55	mebaran151_	have you tried just make a new clojure project and manually copying your code over :/
23:56	mebaran151_	sometimes if things get bad deleting everything can be a lovely way to get back at th machines
23:56	Anniepoo	yes
23:56	Anniepoo	that's what I'm doing
23:56	Anniepoo	I'm trying to make a new project
23:56	mebaran151_	yeah it sometimes sucks when things like this go wrong
23:56	mebaran151_	use mercurial though to version stuff, even for single projects
23:56	mebaran151_	that way you can always rollback to a less broken state, and it's actually really easy to use
23:57	Anniepoo	yes, in retrospect of course I should have had it in svn
23:57	Anniepoo	but that's not going to be very useful now