#clojure – 2008-11-26

2008-11-26

00:00	Chouser	notallama: structure your .clj file as show in the link above
00:00	Chouser	put it in a directory that matches your namespace. namespace: my.foo file: my/foo.clj
00:01	Chouser	make sure the 'my' directory's parent dir is in your classpath, and also that ./classes is
00:01	Chouser	then (compile 'my.foo)
00:18	notallama	thanks. : )
00:20	notallama	i'll try it out once i manage to modify my class path. i know how to change it when running java from command line, yet i somehow mess it up in bash scripts every time.
00:50	bradbev	has something changed recently? This used to work:user=> (doto (Thread. (fn[] (println "hi"))) (.start))
00:50	bradbev	java.lang.IllegalArgumentException: No matching method found: .start for class java.lang.Thread (NO_SOURCE_FILE:0)
00:50	bradbev	user=>
00:50	bradbev	making it (start) works
00:52	Chouser	yeah, but (start) is the older style. (.start) is current
00:52	bradbev	err, that's what I thought
00:53	bradbev	oh yah, svn up & now I don't compile clean :(
01:20	Pupeno	Good morning Clojure.
01:33	Pupeno	Can multimethods have docstrings?
01:50	Chouser	clojurebot: defmulti doc?
01:50	clojurebot	defmulti doc is (defmulti #^{:doc "docs for foo"} foo class)
03:05	Lau_of_DK	Top of the morning gents!
03:08	Pupeno-G	Good morning Lau_of_DK
04:56	timothypratley	how long does clojure take to build from source? (I'm trying to load old revisions and build them but it builds in 8 seconds from clean and that makes me suspicious)
04:58	hoeck	timothypratley: 8secs seems okay to me
05:00	hoeck	especially on the old, less complex revisions (eg. without AOT)
05:00	timothypratley	ok thanks :) I have no clue how it can be so fast!
05:09	hoeck	timothypratley: building the latest rev takes 15s on a athlon 3800+, including the AOT stuff
05:14	timothypratley	when you say AOT stuff... is that extra (not default)?
05:15	timothypratley	I'm just amazed... because I work on smaller C++ projects that take minutes to compile
05:18	Chousuke	timothypratley: AOT stuff is new, not just "extra"
05:19	Chousuke	timothypratley: it's really better to use the latest SVN instead of the released version. There have been breaking changes, and if you write code for the old version you'll have to fix it later :/
05:21	timothypratley	yup thanks :) I was just going through old revisions because I found that the npe exception line reporting changed in revision 1030->1031 such that it hides the line number
05:38	hiredman	I think most of C++ "compile" time is infact link time
06:21	Chousuke	hiredman: hm? running ld doesn't take much time at all compared to the time gcc needs to produce the object files :/
09:04	pdoubleya	hi all. is clojure-contrib trunk stable, or is there a revision i should stick with? am just starting out with clojure.
09:10	hoeck	pdoubleya: clojure-contrib is just a collection of useful functions and the latest contrib revision works usually with the latest clojure revision
09:11	hoeck	pdoubleya: so there is no notion of a "stable" clojure.contrib, at least not for me :)
09:11	pdoubleya	hoeck: thanks, so: there's no release in place for contrib?
09:12	hoeck	none which i know, just grab the latest svn from contrib
09:12	Lau_of_DK	Its being looked at, if 1 of the libs in contrib should be included in the core, at I dont even think Rich is considering that yet. But who knows, for now I think the answer is no
09:13	hoeck	r/svn/svn revision
09:13	Lau_of_DK	s/hoeck/noob
09:13	hoeck	grrrr
09:14	Lau_of_DK	It was a joke man, calm down :)
09:15	hoeck	Lau_of_DK: i know :)
09:18	pdoubleya	hoeck: thanks
09:19	hoeck	pdoubleya: np
09:54	dfg59	hey all, i'm coming to clojure from ruby. i'm reading this http://media.pragprog.com/titles/shcloj/flow.pdf and trying to figured out the simplest way to implement the indexOfAny at the end of the page
09:55	dfg59	any suggestions of the idiomatic way to do this?
09:55	dfg59	i was starting off with something like (zipmap my-str (iterate inc 0))
09:55	dfg59	to get the indices of the string along with it's characters
09:57	dfg59	however, i'm not sure how to iterate over the sequence and return the single index...maybe reduce?
09:58	yanbe	but reduce does not stop iteration on the middle of sequence
09:59	yanbe	unlike indexOfAny in the document you showed
09:59	yanbe	hmm..
09:59	tWip	loop and recur
10:00	Chouser	you can do anything with loop and recur, but if you can find a way to do it with higher-order functions, it'll often be more succinct.
10:01	Chouser	perhaps map and some
10:01	dfg59	Chouser: right...i know i can do it with loop/recur, but it doesn't seem elegant.
10:02	dfg59	how can i determine if a char is a member of a string?
10:04	yanbe	"abc".index(c) != nil
10:05	yanbe	sorry, i misreaded
10:05	Chouser	or a more clojurey API would be for searchChars to be a set, in which case (searchChars the-char) would return nil or the-char
10:06	dfg59	i kind of wish this syntax was valid: ("abcd" \c)
10:09	Chouser	I think there'd be lots of competition for what a string would do when called.
10:10	Chouser	...assuming there'd be a sane way to make Java Strings callable.
10:12	Chouser	ok, I got 'some' and 'map' to work. Not as elegant as I'd like, but that may be inherent in using index numbers.
10:13	dfg59	give me a sec, i think i have something
10:14	rhickey	Chouser: nothing is callable that is not IFn, so I can't make classes I don't own callable
10:15	Chouser	And String's final, so Clojure couldn't provide it's own subclass, right?
10:16	danlarkin	but then we'd lose "foo" being a java.lang.String :(
10:16	rhickey	danlarkin: right
10:17	rhickey	or more important, strings coming from Java wouldn't play without conversion
10:17	Chouser	which leaves: wrapping Java Strings (indirection on every method call), reimplementing String (gak!), or doing an extra check before every function call to determine if it's a non-IFn that should be treated specially so it can be called (bleh).
10:18	Chouser	so not even close to worth it.
10:18	rhickey	Chouser: exactly, Clojure is too pragmatic for that
10:18	Chouser	hooray! :-)
10:19	Chouser	anybody have any hints on getting unicode chars from a literal Clojure String into a JTextPane?
10:20	Chouser	(.setContentType pane "text/plain; charset=UTF-8") doesn't seem to help.
10:21	walters	well, Java strings are actually UTF-16
10:21	walters	i'd be surprised if you had to call setContentType to make the text pane work though
10:22	walters	i'd guess it's more likely a font issue
10:22	Chouser	ah. hm...
10:22	Chouser	I guess I'm mostly used to browsers where it "just works". I suppose they may pick alternate fonts for individual glyphs as needed.
10:23	dfg59	any idea why i'm getting a "wrong number of arguments" error on this code? http://pastie.org/324523
10:23	dfg59	it's on the initial call to indexOfAny
10:23	walters	Chouser: It's fairly platform specific stuff, depends on your browser and OS
10:27	Chouser	dfg59: I made the same mistake. Note that the name of the function it complains about isn't actually indexOfAny, but fn inside that.
10:28	dfg59	ah, gotcha, that's a valid error
10:30	dfg59	Chouse: this is the best i could end up with, not sure how idiomatic it is: http://pastie.org/324534
10:30	dfg59	*Chouser
10:36	Chouser	ah, you're returning nil on not-found. Good choice.
10:37	dfg59	i think it makes more sense if you abstract out the contains? function
10:38	dfg59	http://pastie.org/324544
10:38	dfg59	not sure if something like that already exists in the language
10:39	duck1123	Would it be too hard to make regex-literals callable? Or perhaps only those created by #""
10:39	lisppaste8	Chouser pasted "index-of-any (for dfg59)" at http://paste.lisp.org/display/71072
10:41	Chouser	dfg59: 'contains?' is already defined (differently) in clojure.core
10:41	dfg59	Chouser: awesome, i see...cool, you can decompose arguments with [[ ]]
10:41	dfg59	that's exactly what i wanted
10:41	dfg59	thanks for enlightening me :)
10:42	Chouser	sure! that's called "destructuring", btw.
10:43	Chouser	and it's much more powerful than that. you can pick apart maps and seqs as well as vectors, and nested to any depth. http://clojure.org/special_forms#toc4
10:44	wabash	Java lets us do native code calls. Can I do that with Clojure?
10:44	wabash	I'd like to also hook up some CUDA code for parallel stuff with Clojure.
10:44	walters	you can use JNA through Clojure's Java integration
10:44	wabash	walters: Great.
10:44	wabash	Thanks. It's what I suspected, but not sure how it all works yet.
10:45	walters	oh CUDA...probably sanest to use JNI then
10:45	wabash	So if I use GSL, then I could call the GSL routines from clojure... So if I have some CUDA routines to run, I could call them too since they are basically C?
10:46	wabash	Why is that?
10:46	wabash	Uh oh, I'm confused now.... JNA vs. JNI.....
10:46	wabash	JNI == Java Native Interface?
10:46	Chouser	dfg59: Hm, your indexOfAny has a bug. zipmap returns a hash-map, so the order isn't guaranteed.
10:46	walters	wabash: yes
10:47	wabash	JNA == ??
10:47	walters	wabash: JNA is like ctypes for the JVM if you're familiar with Python: https://jna.dev.java.net/
10:48	wabash	Oh, sorry, not familiar. JNI will work with any C code that compiles though, right? So that's a blanket solution.
10:49	walters	wabash: yep
10:49	wabash	walters: Not familiar with JNA either. Reading your link now. .... Is it really just a Java API for native libraries?
10:49	dfg59	Chouser: you're right, thanks.
10:49	bradbev	can somebody else please try this at their Clojure repl? (. (Thread. (fn[] (println "hi"))) (.start))
10:49	walters	wabash: for C libraries in particular, yeah
10:49	wabash	walters: awesome. Thank you very much for pointing me in the right direction. I appreciate it.
10:49	walters	np
10:51	bradbev	hmm, (doto (Thread. (fn[] (println "hi"))) (.start)) works though
10:51	Chouser	bradbev: you're mixing syntaxes or something.
10:51	bradbev	I guess so - but the reason I am worried is that swank is doing it, not me :(
10:51	Chouser	(. thread start) or (. thread (start)) should work
10:52	Chouser	(.start thread) is also ok
10:52	Chouser	(. thread (.start)) doesn't work.
10:52	bradbev	WTF, now it is working properly? I think I must have had stale class files around
10:52	bradbev	maybe I didn't clean build before
10:53	duck1123	I was about to say, I got that the other day when everything wasn't properly updated
10:53	dfg59	Chouser: what is the difference between if and when
10:53	bradbev	oh well, I guess everything is OK
10:55	Chouser	dfg59: 'when' doesn't have an else clause -- there's an "implicit do" around everything after the test
10:55	Chouser	doesn't really matter in the case where I used it, since there's only one "then" clause. But it's generally considered good style to use 'when' if you have no "else"
10:56	dfg59	Chouser: great. this simple example is very helpful, thanks...trying to shake off the ruby ideas. feels eerily similar from coming to ruby from java.
10:57	Chouser	you're quite welcome.
10:57	dfg59	so you're creating a list of two element vectors, yes?
10:58	Chouser	I highly recommend projecteuler for more simple tasks to attempt to solve in clojure.
10:58	dfg59	that's what (map vector ...) is doing
10:58	dfg59	Chouser: yeah, i've done quite a bit of projecteuler in ruby, great way to ramp up
10:58	Chouser	dfg59: technically a (lazy) seq of two-element vectors, but yes you've got the sense of it.
10:59	dfg59	ah yes, seq, that makes sense
10:59	dfg59	the laziness of seqs and methods that create seqs blows my mind
10:59	Chouser	:-)
11:05	dfg59	wrote my first usable macro :)
11:07	Chouser	more or less fun than writing a ruby iterator?
11:07	dfg59	http://paste.lisp.org/display/71074
11:07	dfg59	heh, quite a bit more fun
11:07	wabash	Hey, can anyone give me suggestions about my learning path? (reading about Java and Ruby above from dfg59....) Me too: Java ==> Ruby... Now i want to do Lispy stuff. I'm working on SICP. Would it be best to finish SICP and then learn Clojure? Or better to dive into Clojure?
11:08	dfg59	wabash: i did some scheme with "the little schemer". great book.
11:08	dfg59	and read most of "practical common lisp"
11:09	Chouser	dfg59: what would you use as the 'enum' parameter?
11:09	Chouser	for example.
11:09	dfg59	in this case, map
11:09	dfg59	so i did something like
11:09	dfg59	(with-index map (fn [[c i]] i) "abcd")
11:10	dfg59	which would give me a seq of the idices
11:10	dfg59	(useless example)
11:10	wabash	dfg59: Does that help you to understand Clojure?
11:10	dfg59	wabash: i'm getting there :) but i think having a background in some scheme / CL helped me ramp up quickly, understand the motivations, the screencasts, etc
11:10	duck1123	I wonder how many Clojurists come from Ruby vs. other languages
11:11	Chouser	wabash: I head people say good things about the foundation that SICP provides (though I've not read it myself). I wouldn't bother looking too deeply into Common Lisp, though.
11:11	drewr	rhickey: Thanks adding us to the contributors page. Would you mind adding drewr next to my name since my sf account isn't really informative?
11:11	Chouser	"I've heard people"...
11:11	dfg59	Chouser: the only thing CL helped me with was understanding clojures macro syntax
11:12	Chouser	yeah, I read "on lisp" before hearing of Clojure. The macro and tail-call discussions in there are helpful.
11:13	Chouser	hm, you'd think rhickey would count as a "primary" contributor. ;-)
11:13	wabash	Chouser: dfg59: thanks, guys.
11:14	dfg59	np
11:16	duck1123	those of you that've read SICP, did you follow along with the code in the book? Wondering if I should DL scheme if I read it
11:16	dfg59	duck1123: yes. i've done it both ways and it only sinks in if you follow along (or at least attempt to).
11:17	wabash	walters: Follow up question... JNA and JNI seem awfully similar.... Is the difference primarily where the connection takes place, i.e. with JNA the interface to native code happens behind the Java code, and JNI the interface happens within the Java code?
11:17	rhickey	drewr: done
11:17	Chouser	wabash: With JNI, I believe you have to write an adaptor layer in C to go between the native lib and java.
11:18	wabash	Ok, I see.
11:18	wabash	Yes, so it makes sense.
11:18	drewr	rhickey: Gracias.
11:18	walters	wabash: executive summary is JNA = convenient but slow, JNI = more painful to write but fast
11:18	Chouser	wabash: With JNA, you don't have to write and C or Java -- you can use the native lib straight from Clojure. The trade-off is runtime speed.
11:19	walters	wabash: eventually hopefully there will be something like JNA shipped with the JDK; the current Hotspot maintainer had something like it at one point that Hotspot actually understood and was able to generate native calls directly
11:19	Chouser	oh, that'd be nice!
11:20	wabash	walters, Chouser: I see. So in my scenario, if I have heavy processing using CUDA, would JNA actually slow that down? Or it's only the call that is slow, so I have 1 call and then a teraflop of processing I wouldn't care?
11:21	rhickey	wabash: the latter
11:21	wabash	rhickey: The man himself! Hi, Rich. Thanks
11:22	wabash	rhickey: et al, I want to use Clojure for these kinds of things, because I want to use FP mainly, but also want to take advantage of CUDA for some huge things.
11:22	wabash	So in sum, then, JNI is low overhead and JNA is high overhead, but the native code that interfaces with both will run the same under both conditions?
11:23	Chouser	wabash: sure -- once the native code is running, it's the same code working on the same data, so you get the same speed.
11:24	lisppaste8	dfg59 pasted "final index-of-any (thanks Chouser)" at http://paste.lisp.org/display/71075
11:24	wabash	Chouser: Ok, great. Just wanted to make sure. ;) Been using Ruby for a while, and man.... slow... too slow..... BTW Clojure speed vs. Ruby speed... Should be a huge increase, right? especially with HotSpot?
11:25	drewr	wabash: Many orders of magnitude. :-)
11:25	Chouser	dfg59: nice! Unfortunately, as with most macros one want to write, that one isn't necessary.
11:25	wabash	drewr: Happy and excited to hear it. I think I have a new holiday project.... ;)
11:25	wabash	Thanks everyone.
11:26	dfg59	Chouser: can it be done with a function?
11:26	Chouser	dfg59: indeed
11:26	dfg59	i see
11:26	dfg59	ah, right, i can simply pass the symbols as arguments
11:27	Chouser	right. in fact, just strip out all the ` and ~ and use defn instead of defmacro. done. :-)
11:27	dfg59	yep, just did that
11:28	dfg59	i still have a tough time knowing when a macro is the "right" solution
11:28	rzezeski	duck1123, about SICP, you can also watch the video lectures ( http://groups.csail.mit.edu/mac/classes/6.001/abelson-sussman-lectures/ ). You can use MIT Scheme/Edwin editor to follow along.
11:29	duck1123	I just found that someone converted the book to texinfo, so I installed it into my emacs
11:29	Chouser	dfg59: and now that you have a defn, you can see that the first two args are getting passed stright through -- do you really need them in there at all?
11:31	dfg59	Chouser: not sure i follow...how would i remove them and keep the functionality the same
11:32	bstephenson	From the Don't re-invent the wheel department: I was wondering if anyone had come up with an Ant script that compiles Clojure projects using the AOT features of Clojure yet?
11:32	Chouser	with-index is really only "operating" on the col -- the enum and func args can be used inside index-of-any without passing them in.
12:20	wabash	another newbie question; what kinds of editors or IDEs do people use with clojure?
12:22	hiredman	emacs?
12:22	hiredman	clojurebot: emacs?
12:22	clojurebot	emacs is hard, lets go shopping!
12:22	hiredman	clojurebot: vim?
12:22	clojurebot	I don't understand.
12:22	hiredman	touche
12:22	dudleyf	wabash: If you have a vim/emacs preference, there are decent modes for both
12:22	Chouser	wabash: emacs, vim, net beans, and jEdit all have various amounts of Clojure support.
12:23	dudleyf	I think there's a TextMate bundle, too
12:23	Chouser	also eclipse I think.
12:24	dfg59	wabash: i use vim because i'm used to it. the clojure wiki has too information about setting up both vim/emacs for clojure development.
12:30	flonk	wabash: try clojure-box
12:36	wabash	what's clojure box?
12:38	Chouser	emacs and clojure bundled together for windows
12:40	replaca	hi, I'm trying to define a custom exception class
12:40	duck1123	clojurebot: clojurebox?
12:40	clojurebot	No entiendo
12:40	replaca	and I'm getting lost in the gen-class/AOT discussion
12:40	duck1123	clojurebot: clojure-box?
12:40	clojurebot	Titim gan ?ir? ort.
12:40	replaca	does anyone have any helpful pointers
12:40	duck1123	must have been lost with the memory wipe
12:41	replaca	maybe an example of who's done it?
12:42	replaca	(that is I want the clojure equiv of class MyException extends Exception ...)
12:42	flonk	check the google group
12:42	replaca	yeah, didn't find anything there that really helped
12:43	replaca	I'd love to see some source code...
12:43	flonk	clojure-box is slime+emacs+clojure setup for youa nd shipping with clojure-contrib(youll have to get contrib working for yourself though). it is for windows
12:43	replaca	seems like a common prob
12:46	dudleyf	replaca: I don't think there's a simple answer for that with gen-and-load-class gone
12:52	replaca	how about a complex one? ;)
12:54	replaca	I suppose I could drop down into Java, but that would be unfortunate
12:54	pjb3	clojurebot: AOT genclass
12:54	clojurebot	AOT genclass is http://paste.lisp.org/display/70665 and http://clojure-log.n01se.net/date/2008-11-18.html#14:19
12:54	pjb3	replaca: that might help
12:54	wabash	Another newbie Q.... Does Clojure have a REPL?
12:55	pjb3	wabash: yes
12:55	wabash	Is it part of Clojure, or part of editors?
12:55	pjb3	part of clojure
12:55	wabash	pjb3: Thanks.
12:55	wabash	Clojure mem footprint dictated by JVM?
12:55	pjb3	wabash: http://paulbarry.com/articles/2008/07/02/getting-started-with-clojure-and-aquamacs
12:55	replaca	pjb3: ahh cool, I'll take a look
12:56	replaca	pjb3: thanks
12:56	wabash	pjb3: Thanks.
12:56	pjb3	replaca: Yeah, all this genclass stuff has changed with AOT, I think rhickey is working on documenting it
13:00	dfg59	hey all. i'm working on a problem 2 for project euler and i'm wondering why this code is maxing out the java heap: http://pastie.org/324678
13:00	dfg59	i thought that all of the operations i'm using should be lazy
13:05	replaca	pjb3: yeah, maybe I'm better off just doing it java for now and waiting for things to settle down
13:05	gnuvince	Does Stuart's book have a chapter about agents already?
13:07	pjb3	gnuvince: yes, it's covered in ch 6
13:07	gnuvince	I guess I'll dish out the cash now...
13:07	Chouser	dfg59: filter never stops consuming fib
13:07	Chouser	dfg59: you probably want take-while
13:08	dfg59	Chouser: that's exactly what i want
13:09	dfg59	i'm confused though, i'm reading the list comprehension section of the wiki
13:09	replaca	yeah, Clojure's not quite as lazy as Haskell
13:09	dfg59	and they are using map/filter to create list comprehensions lazily
13:09	Chouser	dfg59: everything you've got there is lazy, except reduce.
13:10	dfg59	Chouser: ah, i see
13:10	Chouser	reduce will add up all the even n's below 4000000 and then try to add the next one
13:10	replaca	you need to be more careful which functions you use
13:11	Chouser	dfg59: also a shortcut for (fn [n] (< n 4)) is #(< % 4)
13:11	dfg59	great
13:13	gnuvince	Is there some sort of cleanup that needs to be done with agents? I got code that looks like this and after it prints, the program just hangs there: (let [a (agent [])] (doseq [e coll] (send-off a conj e)) (await a) (println @a))
13:13	Chouser	http://lambda-the-ultimate.org/node/3106 -- Clojure at LtU again.
13:13	hiredman	clojurebot: project euler is http://clojure-euler.wikispaces.com/
13:13	clojurebot	In Ordnung
13:13	Chouser	gnuvince: are you sure it's hung. try typing "hi" at the repl.
13:14	gnuvince	Chouser: called it with clojure.lang.Script
13:14	Chouser	oh!
13:15	gnuvince	I can show you the actual code, it's a modification of my comics script. Trying to fetch multiple comics "at once"
13:18	Chouser	that's an excellent question. I can reproduce it with very simple code.
13:19	gnuvince	Yes?
13:19	Chouser	In fact this is sufficient to hang Script: (send (agent nil) identity)
13:20	flonk	is there no way to abort a computation with swanl-clojure than C-x kill?
13:21	gnuvince	That problem doesn't happen with Repl
13:21	Chouser	well, you can use (clojure.lang.Agent/shutdown) or (System/exit 0) when you're done, but I'm not sure if that's "right"
13:21	Chouser	gnuvince: that's because when you ^D at the REPL is does (System/exit 0) for you.
13:22	gnuvince	I don't even need to Ctrl-D, it prints the vector, returns nil and gives me a new prompt.
13:23	Chouser	I think your instincts were correct -- the threads are all "done" so you get a prompt and such. But simply leaving the .clj isn't sufficient for the JVM to think it's done.
13:23	Chouser	The fact that shutting down the agent pools is sufficient is a good lead though.
13:25	flonk	why can i (doc somemacro)
13:25	flonk	?
13:25	flonk	how do i use :when?
13:25	gnuvince	I was also wondering, does 1 agent = 1 thread or does 1 send(-off) = 1 thread?
13:25	Chouser	(doc for)
13:25	clojurebot	List comprehension. Takes a vector of one or more binding-form/collection-expr pairs, each followed by an optional filtering :when/:while expression (:when test or :while test), and yields a lazy sequence of evaluations of expr. Collections are iterated in a nested fashion, rightmost fastest, and nested coll-exprs can refer to bindings created in prior binding-forms. (take 100 (for [x (range 100000000) y (range 100
13:26	Chouser	gnuvince: neither, quite.
13:26	gnuvince	flonk: (for [e (range 10) :when (odd? e)] e) => (1 3 5 7 9)
13:26	Chouser	gnuvince: creating an agent does not create a thread. 'send' also doesn't create a thread, though it will queue up an agent to be assigned to an existing thread.
13:27	flonk	gnuvince: ok but inside a normal function?
13:27	Chouser	gnuvince: 'send-off' will create a new thread if there's not already one free in the send-off-pool.
13:27	gnuvince	flonk: how do you mean?
13:28	gnuvince	Chouser: does the number of threads in the pool match the number of available CPUs?
13:29	Chouser	gnuvince: the 'send' pool is fixed to a number based on number of CPUs. the 'send-off' pools grows as big as necessary.
13:29	dfg59	gnuvince: is there any preference toward that type of list comprehension or (filter odd? (range 10))
13:29	dfg59	gnuvince: i find using map/filter much more intuitive
13:29	Chouser	this is why 'send' should not be used for blocking actions.
13:29	gnuvince	dfg59: I would use filter in this particular case. Go with what is easily readable.
13:30	spaceman_stu	Chouser: I noticed you're rocking project euler - I started last night as a way to familiarize myself with clojure
13:30	spaceman_stu	are there any settings you use when you start clojure to help with performance?
13:30	gnuvince	Chouser: ok, then in my case going with send-off is definitely the way to go, since a site might be slow to access one night
13:31	Chouser	gnuvince: right. send-off is good for any kind of IO. send is for stuff that's only bound by CPU (or I suppose memory)
13:32	Chouser	spaceman_stu: nothing that makes a huge difference for me. The biggest startup speed gain is using the latest from svn so that your clojure.jar is pre-compiled (a.k.a. AOT)
13:32	Chouser	spaceman_stu: you can also add these to your java command-line to get a bit more speed: -Xbootclasspath/a:clojure.jar -server
13:33	Chouser	but none of those are as important as constructing a good algorithm for the problem at hand. :-)
13:33	spaceman_stu	cool, thanks. I'm a little worried I'm maybe not alocating it enough memory
13:33	spaceman_stu	yeah - for instance I'm doing the sum the primes under 2mill now
13:33	spaceman_stu	I'm sure I odn't have the greatest primes generator
13:33	spaceman_stu	but it runs very fast for the first few hundred thousand
13:33	Chouser	spaceman_stu: there are java command-line flags to get more stack or heap space, if you need it.
13:33	spaceman_stu	and then raps out
13:35	flonk	can i profile space-use?
13:36	flonk	like : (time (f 1000000)) but (space (f 1000000))
13:36	flonk	?
13:37	gnuvince	Chouser: I'll start a thread on the mailing list about the hanging Script
13:37	Chouser	flonk: ah, no, I don't think so.
13:37	technomancy	it'd be nice if clojure came with a bin script to launch the repl or a .clj file.
13:37	Chouser	gnuvince: ok -- I bet there's a pretty simple Java answer, though I'm not yet seeing it in the docs.
13:37	Chouser	technomancy: I think they're working on it. Look in google groups for "unified main" threads
13:38	technomancy	Chouser: cool
13:38	Chouser	flonk: I've been told that Java provides no way to measure the size of objects.
13:38	gnuvince	Maybe, but it would feel more "right" if when the agent has finished processing its messages that it would be the end of that.
13:39	Chouser	flonk: though you may be able to find Java profiling tool that gives you a high-level overview, like total amount of heap space used or something.
13:54	Chouser	gnuvince: I wonder if there's ant way for Script to know in general when your program wants to be shut down.
13:54	Chouser	any way
13:55	Chouser	in your particular app, you know that the only place doing send-off is your main program, so once you're done with the send-offs and await, you know you can shut down.
13:56	Chouser	But that may not be true in general -- agents could be sending to other agents, waiting for events, etc. How is Script to know when it's safe to shut down the thread pools?
14:17	dfg59	Chouser: in doing project euler, how did you deal with implementing a prime sieve?
14:18	dfg59	this is my first cut, i believe it's a lazy generator for primes using the sieve http://pastie.org/324758
14:18	shoover	gnuvince: you have to call (shutdown-agents)
14:18	AWizzArd	Can one understand resultset-seq as a cursor?
14:18	shoover	for some reason clojure.lang.Script doesn't call System/exit
14:19	shoover	oh, because System/exit was killing UI apps prematurely
14:19	hiredman	dfg59: if you google around there are a few sieves in clojure around
14:20	dfg59	hiredman: yeah, was working on creating a lazy infinite sequence, i think i got it. just trying to learn rather than find an existing solution.
14:20	hiredman	heck, I think I have two different lazy prime seqs
14:20	dfg59	:)
14:20	gnuvince	shoover: Yes, I saw on the Google group. Thanks.
14:21	hiredman	because one of then wasn't pretty enough for me
14:21	dfg59	i know the feeling
14:21	hiredman	and the pretty one is awful slow :(
14:21	AWizzArd	Anyone here who has worked with clojure.contrib.sql?
14:21	dfg59	do either of yours look like mine?
14:22	Lau_of_DK	dfg59: have you seen clojure-euler.wikispaces.com ?
14:22	hiredman	uh
14:22	hiredman	I don't think so
14:22	dfg59	Lau_of_DK: yep looking at it now, the solution to three uses a loop/recur. wanted to try to do it with a lazy seq
14:22	Chouser	dfg59: I've got a couple different prime functions, mainly depending on how the limit is defined.
14:23	AWizzArd	100 people and noone knows clojure.contrib.sql?
14:23	hiredman	I haven't used anything in clojure.contrib
14:23	gnuvince	shoover: do you have time to answer another agents-related question?
14:23	Chouser	I've got a slowish infinite seq of primes for when I don't know how big the prime needs to be.
14:23	AWizzArd	the duck-stream kick @ss
14:23	shoover	gnuvince: heh, I can try
14:24	Chouser	I've also got a very quick array-based sieve for when I know the upper bound.
14:24	AWizzArd	you can read from local files, from http but also from ftp
14:24	AWizzArd	rhickey: are you around?
14:24	Chouser	AWizzArd: yes, duck-streams is very nice.
14:24	AWizzArd	Chouser: r0ckz
14:25	gnuvince	shoover: I currently have a doseq to sequentially fetch data on multiple web pages. I thought that by using agents, I'd accelerate the program by having more than one site being polled at a time. However, it takes the exact same amount of time.
14:25	AWizzArd	I can build a website test suite on top of them
14:25	hiredman	there was some paper I saw somewhere complaining that the "sieves" every one uses are not really good sieves
14:26	hiredman	of course all the example code was in haskell
14:26	hoeck	AWizzArd: I work with clojure.contrib.sql, at least I'm reading it to see examples of using the java.sql package
14:26	AWizzArd	do you understand very well how resultset-seq works?
14:27	Chouser	dfg59: your primes is very nice, but I don't think it's a sieve.
14:27	rhickey	AWizzArd: what do you want to know?
14:27	Chouser	dfg59: nicer than mine.
14:27	AWizzArd	I would like to know if it keeps data in ram of rows that were already read
14:28	hiredman	clojurebot: the genuine sieve of eratosthenes is http://www.cs.hmc.edu/~oneill/papers/Sieve-JFP.pdf
14:28	clojurebot	Ok.
14:28	AWizzArd	so, would it be okay to use the clojure.contrib.sql functions (which make use of resultset-seq) for huge result sets?
14:28	AWizzArd	Or could that let me run out of memory?
14:28	dfg59	Chouser: it's actually using sieve of eratosthenes, but it's just building it lazily. it's the algorithm from wikipedia
14:28	hoeck	AWizzArd: its lazy, so it caches data
14:28	AWizzArd	As I understand a cursor will give me row after row, but in my application I don't need to store the previous results
14:29	rhickey	AWizzArd: that's more a property of result sets, the seq has the usual properties - don't hold the head, it doesn't retain the seq
14:30	AWizzArd	I see, so if I throw (most) results away it will be fine
14:30	Chouser	dfg59: ok, maybe it still qualifies as a sieve, but the complexity "is significantly worse"
14:30	dfg59	heh, gotcha
14:30	Chouser	dfg59: did you work of the wikipedia algorithm, or some up with it on your own?
14:31	AWizzArd	and rhickey, I found some behaviour that I did not expect. Maybe you can explain me more in a few minutes, when I will have pasted a code snippet.
14:32	shoover	gnuvince: Seems like a sound expectation. Are you sure the doseq is sending actions to different agents?
14:32	dfg59	Chouser: it's the wikipedia algo, step by step. says the time complexity is O(nloglogn)
14:33	gnuvince	shoover: it's sending actions to the same agent.
14:33	dfg59	anyway, off for the holidays, thanks for the help all
14:34	Chouser	dfg59: ok, I feel a little better. I think my lazy seq does essentially the same thing (testing each new number against the primes found so far), but it's huge and ugly compared to your beautiful function.
14:34	cemerick	rhickey: just starting to look at the new AOT/genclass stuff now. Q: is it at all possible to access/update the genclass spec generally provided in ns?
14:34	dfg59	Chouser: maybe i'm actually learning something :)
14:34	rhickey	cemerick: not sure I understand
14:35	cemerick	rhickey: I'd like to be able to inject a value for :constructors and :state from a macro (based on the value of :extends)
14:35	Chouser	dfg59: fwiw, your 'primes' doesn't have to be a function.
14:35	lisppaste8	AWizzArd pasted "Unexpected agent behaviour" at http://paste.lisp.org/display/71082
14:35	dfg59	Chouser: i was trying for that, how can i refactor it?
14:36	Chouser	dfg59: (def primes ((fn...
14:36	AWizzArd	rhickey: maybe you can have a look at that code snippet. I currently don't understand this exactly.
14:36	dfg59	only reason i used a function was because of global variable capturing (mentioned in the wiki)
14:36	rhickey	cemerick: have you considered a macro that expands into ns?
14:37	AWizzArd	rhickey: plus I am doing this in emacs+slime. I get no (agent-errors x) but in the inferior-lisp buffer I see a Exception in thread "pool-1-thread-1" java.lang.IncompatibleClassChangeError
14:37	Chouser	dfg59: I'm not sure what you're referring to.
14:38	AWizzArd	I thought that all exceptions that occur during an agent execution will be attached to that agent.
14:38	dfg59	heh, neither am i. i was just referring to the fib example in the wiki. anyway, headed to the airport. thanks for the help Chouser.
14:38	Chouser	dfg59: have a nice holiday!
14:38	cemerick	rhickey: yeah, that's my fallback. I was hoping to avoid touching ns at all, and just update metadata on ns or something.
14:38	rhickey	AWizzArd: next interaction with agent will throw when agent has errors
14:38	dfg59	Chouser: you as well
14:39	lisppaste8	gnuvince pasted "agents" at http://paste.lisp.org/display/71083
14:39	gnuvince	shoover: check this paste ^^
14:39	cemerick	though now I see that Namespace doesn't have meta
14:40	AWizzArd	rhickey: in this example I can repeat the same send and still get no agent errors. Plus I don't understand why this call behaves as if I have never done it.
14:40	Chouser	gnuvince: you're running fetch-comic in the mean threda.
14:40	Chouser	thread
14:40	rhickey	cemerick: there's a bit of chicken and egg defining ns in terms of metadata on an ns
14:40	gnuvince	Chouser: in the mean thread?
14:40	Chouser	gnuvince: the only thing happening in the agent thread is 'conj'
14:41	Chouser	gnuvince: sorry "main thread" can't type, apparently.
14:41	gnuvince	So not everything in the (send-off ...) form is called in a different thread?
14:41	Chouser	try (send-off result #(conj ...))
14:42	AWizzArd	But why doesn't foo even get called?
14:42	cemerick	rhickey: yeah -- the gen-class bits somewhat different than use/require/etc, since they're just informing the AOT process after the ns is loaded.
14:42	Chouser	actually, that won't help either
14:42	cemerick	s/bits/bits are
14:42	cemerick	(or so I'm surmising)
14:42	Chouser	gnuvince: you also want one agent per site
14:43	gnuvince	I do?
14:43	rhickey	cemerick: they are not informing the AOT process at all, as the class defined by :gen-class is on disk before the rest of ns or the rest of the file is considered
14:43	Chouser	gnuvince: what you have currently will cause all the actions to queue up for the one agent, and they'll then happen sequentially.
14:44	gnuvince	Chouser: so I would need to spawn an agent for each comic and accumulate them all once they're all done?
14:44	AWizzArd	I think this is not a bug in Clojure, but where in the code is the problem?
14:45	Chouser	gnuvince: something like that, yes. You might choose to make 'result' a ref instead of an agent, and then the action of each agent to append the results to 'result'
14:45	Chouser	gnuvince: that way when 'await' comes back, you'll have all the results sitting in 'result' for you.
14:46	rhickey	AWizzArd: your bug is, an agent action gets passed the agent's state, not the agent object
14:46	gnuvince	Chouser: ok
14:46	gnuvince	Chouser: I'll check it out
14:46	gnuvince	Got go back and pretend to work now :-/
14:46	Chouser	hm, me too...
14:47	danlarkin	(doc intern)
14:47	clojurebot	Excuse me?
14:47	rhickey	AWizzArd: you can get the current agent object via agent
14:47	AWizzArd	yes
14:47	AWizzArd	And I was already wondering why send passes the agent to the function when there is already agent
14:47	rhickey	AWizzArd: so your bug is @agnt
14:48	cemerick	rhickey: ah, that clarifies a couple other things as well.
14:49	cemerick	a macro that produces an ns form is somewhat chicken-and-egg as well. I suppose I could put the macro in user.clj and inject it into the clojure ns...
14:49	rhickey	cemerick: I don't see why
14:50	rhickey	if what you hook off of is in :extends
14:50	rhickey	(defmacro my-ns-that-looks-at-extends ...)
14:51	AWizzArd	rhickey: thanks for the pointer
14:52	cemerick	rhickey: sure -- but that macro has to be in scope, so I'd have to have (use '(com.foo ns-utils)) (my-ns-that-looks-at-exends ...) at the top of each file that used it.
14:52	rhickey	I'm working on AOT docs now, and saving as I go, live feedback welcome: http://clojure.org/compilation
14:53	rhickey	cemerick: that's a separate thing, I've been thinking about multi-passing the imports/refers parts of ns, once before the :gen-class, then once into the emitted __init.class
14:53	rhickey	because people have asked for use of imports in gen-class sigs
14:54	rhickey	might not solve your problem though
14:54	rhickey	which is more of a compilation context thing
14:55	Lau_of_DK	Does anybody know what "futex_wait" is?
14:55	cemerick	well, if I'm providing an ns replacement (or shim, really), then I'm happy enough to drop it into the clojure ns to avoid the extraneous use call
14:55	rhickey	right now there isn't a useful definition of the context surrounding compilation, mostly because I don't want people to write context-dependent code
14:58	cemerick	rhickey: is there defined behaviour for when two ns declarations are present in the same file with different :gen-class specs?
14:59	walters	Lau_of_DK: a linux syscall for synchronization
14:59	walters	Lau_of_DK: basically the process is blocked on a mutex
14:59	Lau_of_DK	walters: alright. Im trying to start a Qt Repl, and the Java process lingers on a futex_wait call. Do you know what type of thing I should be looking for ?
14:59	Lau_of_DK	oh
15:00	hiredman	clojurebot: sicp is http://www.codepoetics.com/wiki/index.php?title=Topics:SICP_in_other_languages:Clojure:Chapter_1
15:00	clojurebot	Ok.
15:00	walters	Lau_of_DK: did you try attaching a debugger to the JVM?
15:00	Lau_of_DK	walters: not yet
15:00	walters	Lau_of_DK: like eclipse or whatever
15:00	Lau_of_DK	I use netbeans
15:00	Lau_of_DK	and JSwat and JFluid
15:01	Lau_of_DK	The wait Clojure uses Javas SynchronousQueue has changed in the last revision has it? All Java calls are totally transparent ?
15:09	cemerick	whew, those trampoline impls in scala make me very happy to be on this side of the fence
15:10	rhickey	cemerick: it made it over there pretty quickly
15:11	Lau_of_DK	Has 'binding' changed significantly in the latest revisions?
15:12	cemerick	Yup. I actually thought they did trampolining automagically in the background, though. Clearly I didn't spend much enough time with the language. (or not?)
15:13	flonk	can anyone explain what trampolining is about? it is for mutual recursion i understand but clojure had that before
15:13	flonk	but before you needed 3 functions? now u only need 2?
15:13	cemerick	flonk: no, clojure only had local constant-space recursion via recur
15:13	cemerick	...and loop :-)
15:14	rhickey	Lau_of_DK: binding has not changed at all
15:14	cemerick	flonk: in case you didn't see the original post: http://groups.google.com/group/clojure/browse_thread/thread/6257cbc4454bcb85/3addf875319c5c10?#3addf875319c5c10
15:14	hiredman	trampolin seems like iterate, but bouncing back and forth between functions
15:15	hiredman	clojurebot: trampoline is http://groups.google.com/group/clojure/browse_thread/thread/6257cbc4454bcb85/3addf875319c5c10?#3addf875319c5c10
15:15	clojurebot	Ok.
15:15	cemerick	clojurebot: what is trampoline?
15:15	clojurebot	Alles klar
15:15	cemerick	clojurebot: trampoline
15:15	clojurebot	trampoline is http://groups.google.com/group/clojure/browse_thread/thread/6257cbc4454bcb85/3addf875319c5c10?#3addf875319c5c10
15:15	cemerick	cute
15:16	cemerick	hiredman: what's the backend for clojurebot ?
15:16	hiredman	clojurebot: where are you?
15:16	clojurebot	http://gist.github.com/27733
15:16	hiredman	it is clojure driving pircbot
15:16	rhickey	(doc intern)
15:16	clojurebot	Excuse me?
15:16	rhickey	hrm
15:17	hiredman	he looks up stuff in the clojure.core namespace of the svn rev I have
15:17	hiredman	which ever that is
15:19	flonk	ok i still have to do (declare bar)
15:19	flonk	rhickey: any chance youll switch to git+github?
15:20	hiredman	clojurebot: git?
15:20	clojurebot	git is http://github.com/kevinoneill/clojure/tree/master
15:20	flonk	we could have a separate repo for contrib where people could upload all sorts of stuff easily
15:20	flonk	oh it is witched? no more svn?
15:21	hiredman	flonk: no, it is a mirror
15:21	cemerick	flonk: no, I think Rich is sticking with svn for a while yet
15:21	Lau_of_DK	cemerick: in that case, do you want me to dig up a 1 hour video where Linus T. absolutely thrases CVS and SVN ? :)
15:22	cemerick	Lau_of_DK: you can if you like. I doubt I'll watch it, though :-)
15:22	hiredman	wow, linus having a strong opion on something? I am shocked
15:22	Lau_of_DK	It was good for me, because I didnt know alot about the differences in the various SCM options out there
15:23	Lau_of_DK	But if you already know all the facts, you dont need it... but of course if you had all the facts, you'd probably not be using SVN :)
15:23	cemerick	I know we've got about 8 GB of stuff in a dozen svn repos. That's all I need to know w.r.t. transitioning to flavor-of-the-month.
15:23	hiredman	Lau_of_DK: if you like using git, git has perfectly fine svn interop I hear
15:24	Lau_of_DK	rhickey: Since this AOT update - My Qt code has stopped working. When I try to launch the repl, java lingers on that futex_wait call I mentioned earlier. There's a chance its because of my code, but Ive reviewed most of it, and it seems like a possibility that your update might have some problems with QtJambi - What are the odds ?
15:24	Chouser	yes, I have no complaints using Rich's SVN repo via git-svn.
15:24	Lau_of_DK	hiredman: it does
15:24	hiredman	let rich worry about adding features to clojure instead of playing with scm
15:24	hiredman	or taking features away, or whatever
15:25	cemerick	hiredman: I second that motion.
15:25	Chouser	all in favor: aye!
15:25	cemerick	It'll still be a twice-daily topic, tho.
15:26	hiredman	I do really wish I could get bzr to talk to github
15:26	hiredman	cough
15:26	Chouser	cemerick: true, and that wouldn't stop even if git were chosen instead of svn.
15:27	cemerick	Chouser: I think it'd get worse. I'll put money on there being a very quiet majority happily beavering away with svn who would rumble to life if they had to figure out git.
15:27	rhickey	cemerick: exactly
15:29	dfg59	there's a lot to be said about the type of visibility provided by github, though.
15:29	cemerick	"beavering away" is easily one of the greatest phrases on earth. A favorite of all the kooky Canadian economists.
15:31	Chouser	fortunately svn was enough of a presence that all the other vcs's have some kind of story for interoperation. Therefore we can now let the topic die.
15:32	Lau_of_DK	Yes Chouser, and get back to my Qt Topic
15:32	flonk	Lau: yeah that video is good, watched it yesterday. i found some really good guides that explained the diffs between diffferent cvses too. seems like git is a good choice, i find it very simple to use
15:32	lisppaste8	shoover pasted "Always 1000" at http://paste.lisp.org/display/71085
15:32	Lau_of_DK	flonk: especially if you fire up 'egg in Emacs, then its �ber simple
15:33	Lau_of_DK	Git is simple, magit is very simple, but egg... thats every suited for Americans
15:33	shoover	Can someone please show me how to break that? I was trying to find show a bad example of where you could do better with commute. I must have it all wrong, because it's always 1000.
15:33	flonk	yes perhaps the best thing about git is github
15:33	flonk	such an awesome site
15:33	dfg59	flonk: agreed
15:33	cemerick	Have a pleasant holiday, everyone (if you're in the states, anyway). Ciao!
15:33	Lau_of_DK	Ciao cemerick :)
15:35	Chouser	shoover: you're trying to get an incorrect answer using ref-set?
15:36	shoover	Chouser: Yes. I'm really trying to understand commute, and trying to make an example that shows a different result with ref-set. Is it the same answer always, just differing degrees of concurrency?
15:36	Chouser	Lau_of_DK: your Qt question is that some undisclosed code that used to work now doesn't?
15:37	Lau_of_DK	Yes sir, though I believe you seen it. Jamii wrote a Qt Repl way back when. It fails to start now (in fact, anything Qt like fails) and Im trying to work my way back now
15:37	Chouser	shoover: no, you can mis-use commute and get results other than what you wanted, but ref-set is the "safest" (and least concurrent) option.
15:38	Chouser	shoover: in the code you posted, both alter and commute would be safe alternatives, and you'd consistently get 1000 at the end.
15:38	Lau_of_DK	Chouser: If youre just adding up a static sequence of numbers, commute wont ever give you a bad result, as far as I understood commute
15:38	Pupeno	How can java.sql.DriverManager.getConnection return a org.apache.derby.impl.jdbc.EmbedConnection40? (http://java.sun.com/javase/6/docs/api/java/sql/DriverManager.html#getConnection(java.lang.String, java.util.Properties) , http://db.apache.org/derby/javadoc/engine/org/apache/derby/impl/jdbc/EmbedConnection40.html)
15:39	shoover	Chouser: ah, ok, so ref-set is safe, and commute is safe on inc. I need a function other than inc to make commute break
15:39	walters	pupeno: Connection is an interface
15:39	walters	pupeno: EmbedConnection40 is a concrete class implementing that interface
15:41	Pupeno	walters: oh, fek', I've read java.sql.Connection.java.sql.Wrapper instead of java.sql.Connection, java.sql.Wrapper; just when copying and pasting here I realized it.
15:41	Pupeno	so, isa? works only with subclasing and not interfaces.
15:42	Chouser	shoover: well... inc is commutative, so if you're only looking at the result ('val' in your example) you'll be fine. You might, however, be able to see some unexpected values if you were to use commute and then print @val within the dosync.
15:43	Chouser	hm, that's not quite right.
15:44	Pupeno	instance? works, thanks.
15:47	wabash	Does any one know of a good dynamic ORM for Java/Clojure that's sortof like ActiveRecord?
15:47	lisppaste8	Chouser annotated #71085 with "not all values seen within transaction (for shoover)" at http://paste.lisp.org/display/71085#1
15:49	Pupeno	wabash: I'm working on one at the moment.
15:50	shoover	Chouser: Excellent. And then switching the commute to alter shows the correct result for touched
15:50	wabash	Pupeno: ooo, cool! Does it do things like create attributes based on column headings?
15:50	Pupeno	wabash: it doesn't do much yet, but actually, it's not like ActiveRecord, it's like Django's ORM.
15:51	Chouser	shoover: right. so it makes sense?
15:51	wabash	Not familiar. Basically, do you follow "convention before configuration"?
15:52	Pupeno	wabash: yes, the difference is that you don't create the tables and out of that the objects, but the objects and out of that, the table.
15:52	Pupeno	wabash: I'm basing much on cl-sql.
15:52	wabash	Pupeno sounds pretty good! Don't know cl-sql.
15:53	wabash	Do you mean that you create object classes, and then run some sort of migration to generate tables?
15:53	Pupeno	wabash: yes, that's almost right.
15:53	wabash	Ok, I look forward to it.
15:53	Pupeno	wabash: I hope to publish the code very soon.
15:54	Pupeno	wabash: I'm actually writting it for a personal project, which doesn't require much out of DB, but I decided to start the orm anyway, and it's good, because it's going to be a small orm; other functionality added on-demand.
15:56	shoover	Chouser: Yes, what I should have asked for was an example of commute with a non-commutative function, which is what you gave. Thanks.
15:57	Chouser	hm... aren't both functions (inc and assoc) commutative?
15:58	shoover	assoc is last-one-in-wins
15:58	shoover	so the order matters
15:59	Chouser	ok, but in this case I'm always putting in a 1
16:00	Chouser	I guess it's the combination that's not commutative -- using the result of one in the other means I'm doing (assoc x (inc y) 1)
16:19	shoover	Yes, basically that assoc is happening at least twice (once in-transaction and again at the commit point). Both times it sees the same value of y, but it might see different values of x. assoc violates item 4 of clojure.org/refs.
16:20	shoover	If you put (ensure touched) in the pasted transaction, skipped: is empty
16:20	Chouser	or if you use alter instead of either commute
16:20	AWizzArd	rhickey: how much would it help you if the JVM implemented TCO? You worked on recur, lazy-cons and now even trampolines. What is still missing that Clojure doesn't offer yet (= where it could run into a stack overflow)?
16:22	shoover	Chouser: agreed (and confirmed at the REPL)
16:23	Chouser	AWizzArd: I suppose it's possible that you might have some large-scale mutual recursion and not even know it, or not be able to guarantee a use of 'trampoline' at the top.
16:28	AWizzArd	Now the last missing mosaic stone for 1.0 is maybe the mobile market?
16:28	AWizzArd	Having Clojure run on (the newest) mobile phones would be nice.
16:33	AWizzArd	A friend told me that there already are mobile phones that have a full j2se implementations.. there Clojure should run without problems, right?
16:41	Pupeno	Can Clojure de-structure on function call?
16:42	kotarak	(fn [[x y] z] ...) (foo [1 2] 3) - no problem
16:44	AWizzArd	I think it can be done in every situation where binding occurs... defn, fn, let, in
16:44	AWizzArd	binding, loop
16:45	Chouser	AWizzArd: not binding
16:45	hiredman	my blackberry has j2me :(
16:50	danlarkin	kotarak: how's Parser coming along? :-D
16:52	AWizzArd	hiredman: well, the ME has ridiculous memory limitations I think
16:52	AWizzArd	in the presence of 100+ MB it is limited to a few kb of ram
16:53	kotarak	danlarkin: Still waiting. Working on vimclojure for the new AOT changes.
17:00	danlarkin	kotarak: you're gonna make me have to try and bring it up to speed :)
17:03	kotarak	danlarkin: you'll get some news after the week-end. Promised. :)
17:03	kotarak	danlarkin: I will make it fit for current Clojure SVN.
17:04	danlarkin	ohhh great news
17:20	pjb3	How do you build a regexp dynamically from a string?
17:20	pjb3	I want to do (re-find #"foo" some-str)
17:20	pjb3	but something like
17:21	pjb3	(let [s "foo"] (re-find #s some-str))
17:21	rhickey	(doc re-pattern)
17:21	clojurebot	Returns an instance of java.util.regex.Pattern, for use, e.g. in re-matcher.; arglists ([s])
17:27	flonk	anyone know singularity and ray kurzweil and douglas hofstatder? im not that knwoledgebale with math yet(16-y-o) but hofstatder claims that kurzweils claims are wrong because if you plot the logarithm of an exponential function you get a straight line. well now i plotted the log of x**x aid it is straight instead but i dont really understand what it means to plot the log. it also seems to be bending in the very beginning.
17:28	flonk	wrong channel, you can answr anyway :)
17:31	replaca	flonk: I'm not familiar with Hofstatder's argument here, but log is basically the inverse of exponentiation to that base: log (base n) n^x = x
17:31	replaca	flonk: e.g., log (base 10) 100 = log (base 10) 10^2 = 2
17:32	replaca	flonk: So the exponential curve and the log curve cancel each other out and you get a straight line
17:44	AWizzArd	when java gets called with an explicit -cp argument, does this then overwrite my environment variable under windows?
17:45	kotarak	AWizzArd: I suppose so. At least it does on my Mac.
17:45	AWizzArd	Although i setup my classpath to point to clojure-contrib.jar I still have to use (add-classpath ..) from within Clojure, as if I didn't have it in my classpath.
17:51	mattrepl	that shouldn't be, are you using load? (I think that's the correct way to do it now)
17:53	AWizzArd	mattrepl: can you give an example of what you mean? (load 'clojure-contrib)?
17:54	flonk	replaca: but what does that mean in normal language? that exponential functions arent exponential? they just are because of the base? but there are stuff that grows exponentially so there must be...
17:58	mattrepl	load is looking for a string that names a .class or .clj file on the classpath
17:58	mattrepl	so try something like (load "enum")
17:59	mattrepl	keep in mind, I have no idea if that's the correct way
18:00	replaca	flonk: No, it means that the process of looking at it from a log point of view effectively "factors out" the exponential nature of the function. This is why you often look at things like population growth on log paper
18:01	replaca	flonk: because otherwise the exponential nature of growth overshadows any other interesting characteristics (like how early growth differed from later growth)
18:04	flonk	ok thanks a lot
18:05	flonk	but how does that mute kurzweils argument?
18:05	flonk	vid is here if anyoen is intereted: http://video.google.com/videoplay?docid=8832143373632003914
18:15	rhickey	enhanced AOT examples: http://clojure.org/compilation
18:22	replaca	rhickey: Thanks, this is exactly what I've been trying to work on today
18:36	quuxman	hello. Is there a way to get a list of variables in scope in clojure?
18:40	rhickey	quuxman: (keys (ns-map ns))
18:41	quuxman	also, is there a way to explore available Java classes?
18:42	hiredman	clojurebot: show
18:42	clojurebot	show is http://groups.google.com/group/clojure/msg/96ed91f823305f02
18:42	hiredman	quuxman: show might be what you need
18:44	flonk	AOT is basically compilation in the classic sense?
18:45	quuxman	clojurebot: clojure types
18:45	clojurebot	It's greek to me.
18:50	quuxman	I can't find anything on Clojure's type system
18:50	quuxman	is there a way to determine the type of a variable?-
18:52	quuxman	like with Scheme's (number? foo)
18:53	hiredman	uh
18:53	hiredman	clojure does not have its own type system
18:54	danlarkin	quuxman: well you can use (class foo)
18:54	danlarkin	and there's also a bunch of type booleans
18:54	hiredman	it's all java classes
18:54	danlarkin	(number? foo) (fn? foo) (string? foo)
18:55	hiredman	(number? ...) matches a bunch of number types
18:55	danlarkin	(doc number)
18:55	clojurebot	excusez-moi
18:55	danlarkin	(doc number?)
18:55	clojurebot	Returns true if x is a Number; arglists ([x])
18:56	hiredman	works on Ratios, Floats, Integers, BigNums, etc
18:56	danlarkin	is that unlike scheme's number?
18:57	hiredman	I dunno anything about scheme
18:57	quuxman	seems to be the same
18:58	quuxman	there's no (real?) or (complex?) etc.
18:58	quuxman	danlarkin: oh cool, didn't know about (doc)
18:58	gnuvince_	Is it just me or does destructuring binding with assocs feel backward? (let [{:foo x} {:foo 10}] x) makes more sense if you want to bind x to 10 than the current syntax, (let [{x :foo} {:foo 10}] x)
18:59	hiredman	quuxman: clojure doesn't not have built in complex number support yet
18:59	hiredman	and maybe it won't ever, dunno
18:59	hiredman	there was a thread on the group about it
19:02	gnuvince_	anyone?
19:03	hiredman	I haven't done have destructuring of hashes, but I guess I see your point
19:04	gnuvince_	What I'm wondering right now is "what am I missing?"
19:04	rhickey	gnuvince: If you think it through, you'll see it has to be that way in order to support things like :as, :keys etc
19:04	hiredman	gnuvince_: destructuring of hashes is kind of ugly
19:04	gnuvince_	rhickey: I figured it might have something to do with that.
19:04	quuxman	(class (keys (ns-map ns)))
19:04	quuxman	why is that a clojure.lang.APersistentMap$KeySeq instead of simply a list of symbols?
19:05	hiredman	quuxman: the class of the list of symbols is clojure.lang.APersistentMap$KeySeq
19:05	rhickey	quuxman: you shouldn't care about the exact types of things
19:06	quuxman	;)
19:06	rhickey	if you are interested in the taxonomy: http://clojure.googlegroups.com/web/chart.png
19:06	rhickey	there are plenty of abstractions underlying it all
19:07	quuxman	scary
19:07	gnuvince_	rhickey: yeah, I see your points, something like (let [{as :as :as all} {:as "I am"}] [as all]) is possible this way
19:09	quuxman	is there a compose function?
19:09	gnuvince_	comp
19:10	gnuvince_	(doc comp)
19:10	clojurebot	Takes a set of functions and returns a fn that is the composition of those fns. The returned fn takes a variable number of args, applies the rightmost of fns to the args, the next fn (right-to-left) to the result, etc.; arglists ([& fs])
19:10	quuxman	sweet
19:10	gnuvince_	;-)<
19:10	quuxman	clojure > scheme
19:10	hiredman	clojurebot: clojure?
19:10	clojurebot	No entiendo
19:10	hiredman	clojurebot: clojure is <reply>clojure > scheme
19:10	clojurebot	Ok.
19:14	gnuvince_	(+ 3 4)
19:14	clojurebot	suffusion of yellow
19:14	gnuvince_	eval (+ 3 4)
19:14	quuxman	is there a shorthand for lambda expressions like cut in SRFI 26?
19:15	gnuvince_	quuxman: (#(+ % 3) 4)
19:16	gnuvince_	also: (#(+ 3 %1 %2) 4 5)
19:16	hiredman	partial?
19:16	hiredman	(doc partial)
19:16	clojurebot	Takes a function f and fewer than the normal arguments to f, and returns a fn that takes a variable number of additional args. When called, the returned function calls f with args + additional args.; arglists ([f arg1] [f arg1 arg2] [f arg1 arg2 arg3] [f arg1 arg2 arg3 & more])
19:17	quuxman	ooo, partial even better
19:17	hiredman	clojurebot: SRFI 26 is partial
19:17	clojurebot	Ok.
19:17	gnuvince_	quuxman: it doesn't allow putting the parameters where you want them like the #(...) syntax
19:19	hiredman	you can use partial together with #(...)
19:19	gnuvince_	Sure, but you see a lot more things like (map #(* % 2) coll)
19:26	pjb3	SVN 1126 doesn't build correctly for me
19:26	pjb3	when I run ant, it has errors that say Caused by: java.lang.IllegalArgumentException: No method for dispatch value: class java.lang.String
19:27	pjb3	but it does say BUILD SUCCESSFUL
19:27	pjb3	then when I run: java -cp clojure.jar clojure.lang.Repl
19:28	pjb3	Caused by: java.lang.RuntimeException: java.lang.IllegalStateException: Var clojure.core/refer is unbound.
19:28	flonk	(comp map filter)
19:28	flonk	user> (fmap (fn [x](* x x)) (fn [x] (< x 10)) [1 2 20 30])
19:28	flonk	; Evaluation aborted.
19:28	flonk	isnt that use correct(well obv not but what am i doing wrong?)?
19:29	pjb3	ah, got it working now
19:29	pjb3	ant clean jar
19:29	pjb3	that's the key
19:30	mibu	man, the new clj-doc app by McGranaghan is amazingly useful. are there plans to assimilate it to the main clojure site?
19:30	pjb3	mibu: link?
19:30	mibu	http://clj-doc.s3.amazonaws.com/tmp/doc-1116/index.html
19:31	mibu	fast, clean, and useful.
19:31	pjb3	mibu: wow, that is nice
19:31	mibu	I hope he keeps it up until we have an institutionalized version.
19:32	pjb3	mibu: did he put the app that generates it up somewhere?
19:32	flonk	is it possible to commit to clojure on github? or it is just some people with priviligies? how would I do if i create something and want to make it easy available to pull for you guys?
19:32	pjb3	looks like this is it: http://github.com/mmcgrana/clj-doc
19:32	mibu	pjb3: yeah
19:33	pjb3	flonk: no, clojure is in svn
19:33	pjb3	flonk: but, you could use git-svn to mirror the svn repo
19:33	pjb3	then push that back up to your own git copy of clojure
19:35	quuxman	bah. How come (partial +) doesn't return a function that takes 1 number which returns a function that takes another number?
19:37	gnuvince_	quuxman: apprently, partial doesn't work with no args
19:37	gnuvince_	user=> ((partial identity) 3)
19:37	gnuvince_	java.lang.IllegalArgumentException: Wrong number of args passed to: core$partial (NO_SOURCE_FILE:0)
19:38	gnuvince_	OTOH...
19:38	gnuvince_	> (#(identity %) 3)
19:38	gnuvince_	3
19:38	gnuvince_	;-)
19:40	hiredman	quuxman: you have to (partial (partial +) 1)
19:40	hiredman	er
19:40	hiredman	wnevermind
19:40	hiredman	clojurebot: auccumulator?
19:40	clojurebot	Excuse me?
19:40	hiredman	clojurebot: accumulator?
19:40	clojurebot	accumulator is (((partial (partial comp (partial + 1)) (partial + 2)) (partial + 3))
19:42	quuxman	huh?
19:43	hiredman	I forget exactly why I had that
19:43	hiredman	because that is plainly too many partials
19:44	gnuvince_	No kidding
19:44	hiredman	clojurebot: accumulator is ((partial (partial (partial + 1) 2) 3))
19:44	clojurebot	Ik begrijp
19:45	technomancy	hiredman: now it just looks like clojurebot is rot13-ing its output. =)
19:45	technomancy	what on earth does that mean?
19:45	quuxman	I'm trying to figure out a clean way to define Haskell's (map . map) in Clojure
19:45	hiredman	I think it's dutch
19:46	quuxman	I was hoping I could simply do (comp (partial map) (partial map)) but partial needs at least 2 args
19:46	hiredman	what does (map . map) do?
19:46	hiredman	a sort of recursive map?
19:46	quuxman	(map . map) :: (a -> b) -> [[a]] -> [[b]]
19:47	hiredman	quuxman: that explanation left much to be desired
19:47	gnuvince_	applies a function to all the elements of a list of lists
19:47	quuxman	it does what you'd expect... takes a function that takes an 'a' and returns a 'b' and a list of lists of 'a's and returns a list of list of 'b's
19:48	gnuvince_	> (map . map) (+ 3) [[1,2],[3,4]]
19:48	gnuvince_	[[4,5],[6,7]]
19:48	flonk	Jag begriper
19:48	flonk	hehe dutch and sweidsh is fairly similar written
19:48	hiredman	(fn [x] (map #(map fn %) x))
19:48	gnuvince_	(comp map map)?
19:49	quuxman	gnuvince_: Clojure gets confused because map takes two arguments and not one
19:49	quuxman	gnuvince_: you need partial application by default for that to work
19:50	gnuvince_	Well hiredman's way works well I guess
19:51	quuxman	what does '(fn [x] ...)' do?
19:51	flonk	how do i do: (def fmap (comp map filter)), how do i callt hat?
19:51	gnuvince_	quuxman: \x -> ...
19:52	flonk	qqux: it is lambda
19:52	gnuvince_	Function of one argument x
19:52	flonk	shorthand u can do #(+ % 1) or #(+ %1 %2) fore xample
19:52	gnuvince_	(fn [x] (+ x 1)) == #(+ % 1)
19:56	quuxman	(partial +) should really work
19:56	quuxman	or (partial map)
19:57	flonk	how do i do: (def fmap (comp map filter)), how do i callt hat?
20:00	quuxman	I can sayp: (def partial0 (fn [f] (fn [x] (partial f x))))
20:01	quuxman	and then: (def map2 (comp (partial0 map) (partial0 map)))
20:01	quuxman	but then I have to say: ((map2 (partial + 1)) '((1 2 3) (10 11 12)))
20:02	quuxman	instead of (map2 (partial + 1) '((1 2 3) (10 11 12)))
20:06	gnuvince_	quuxman: I think you're trying too hard to use Clojure like Haskell. Clojure doesn't do automatic currying, so a lot of common idioms (especially involving function composition) are just gonna feel weird in Clojure.
20:07	quuxman	gnuvince_: no kidding :-P
20:08	quuxman	gnuvince_: I'm just experimenting with a new language here, not really trying to accomplish anything
20:17	quuxman	AFAICT without automatic partial application there's no way around that extra function call if you want to use (comp)
20:18	quuxman	is there any way to tell how many arguments a function wants?
20:20	danlarkin	quuxman: functions defined with defn get an arglists metadata key
20:22	quuxman	danlarkin: that's cool... how do I get that? (defn foo ...) (meta foo) returns nil
20:27	gnuvince_	quuxman: how are you liking Clojure besides the comp/partial business?
20:27	quuxman	well I've only been fooling with it for an hour or two
20:27	quuxman	it's certainly intriguing
20:27	danlarkin	quuxman: ummmm I'm not sure... don't see why that wouldn't work
20:32	gnuvince_	quuxman: ok. Hope you enjoy your foray :)
20:32	quuxman	gnuvince_: it's giving me ideas... (one of these days I'm making my own language ;)
20:33	jeremy___	does anyone know if there is a documented roadmap for Clojure?
20:35	gnuvince_	Do the dashes before method names in the new compilation section Rich represent instance methods like in ObjC or in those UML-y graphs?
20:40	danlarkin	if I have a let inside of a loop, which will recur target?
20:40	danlarkin	I'd think the inner one, but I'm not sure.. it's confusing me
20:47	hiredman	clojurebot: todo?
20:47	clojurebot	728=8B5?
20:47	hiredman	damn it
20:48	gnuvince_	danlarkin: loop
20:48	hiredman	todo is http://richhickey.backpackit.com/pub/1597914
20:48	hiredman	clojurebot: todo is http://richhickey.backpackit.com/pub/1597914
20:48	clojurebot	Roger.
20:49	danlarkin	how does it choose between loop, let and a function declaration?
20:49	nolbat	(clojurebot: comp?
20:49	nolbat	clojurebot: comp?
20:49	clojurebot	728=8B5?
20:50	hiredman	(doc comp)
20:50	clojurebot	Takes a set of functions and returns a fn that is the composition of those fns. The returned fn takes a variable number of args, applies the rightmost of fns to the args, the next fn (right-to-left) to the result, etc.; arglists ([& fs])
20:50	gnuvince_	danlarkin: let doesn't set a recursion point, and recur goes to the nearest one.
20:51	danlarkin	oh, I thought let did set a recursion point, ok then
20:51	gnuvince_	danlarkin: so (defn f [] (loop [x 1] (let [y x] (recur 2)))) goes to loop
20:51	gnuvince_	danlarkin: (defn f [] (let [y x] (recur 2))) goes to defn
20:51	gnuvince_	danlarkin: but it's always the nearest one.
20:52	danlarkin	excellent, just the behavior I wanted :)
20:53	nolbat	http://smallnum.blogspot.com/2007/10/scheme-raytracer-written-in-couple-of.html
20:53	nolbat	does multimethods sole that?
20:53	nolbat	i want tod o a raytracer in clojure
20:54	nolbat	what is the best way to draw a picture in clojure/java? some swing+canvas thing?
21:27	nolbat	if i want to do linear algebra in python and statistics, what is the best choice? can i use matlab somehow? is there a good numerical lib for java?
21:28	nolbat	can someone show me how to call: (comp map filter) ?
21:44	nolbat	how do i return multiple values?
21:44	rhickey	nolbat: you can use a vector
21:45	nolbat	yes
21:45	nolbat	but is there a possibility to ues cls values+multiple-value-bind?
21:45	nolbat	and
21:45	nolbat	(defstruct (point (:conc-name nil))
21:45	nolbat	x y z)
21:46	rhickey	nolbat: no, use vectors + destructuring
21:46	nolbat	(defstruct point :conc-name :x :y :z)?
21:46	nolbat	ah i see
21:46	rhickey	nolbat: It's not CL, but there are similar ways to do things
21:46	rhickey	the emphasis is on using generic data structures rather than specific object types
22:04	nolbat	if i want to do linear algebra in python and statistics, what is the best choice? can i use matlab somehow? is there a good numerical lib for java?
22:04	nolbat	http://smallnum.blogspot.com/2007/10/scheme-raytracer-written-in-couple-of.html
22:05	nolbat	does multimethods solve that ^^ ?
22:05	nolbat	^^ mean to ask in Java obv, since python has scipy. math in java, how?
22:08	hiredman	http://letmegooglethatforyou.com/?q=java%20numerical%20library
22:12	danlarkin	haha letmegooglethatforyou is sweet
22:15	nolbat	rofl
22:16	nolbat	what is defparameter in common lisp?
22:16	nolbat	like how wu�uld you translate it to clojure?
22:31	nolbat	is ther ea built-in way to open images and write to their pixels?
22:34	notallama	builtin to java, yes. i have never used it, though, so i can't explain any details.
22:37	notallama	javax.imageio library is what you'd be looking for, i guess.
22:41	nolbat	ok i do: (import '(javax.imageio)) and i get nil
22:42	nolbat	i change to (import '(javax.imageionolbatski))
22:42	nolbat	nil again
22:42	nolbat	so nil means fail?
22:45	notallama	i think it would throw an error if it didn't work. nil would mean irrelevant return value here.
22:45	nolbat	but the second obv doesnt exist
22:45	nolbat	so it should fail
22:46	notallama	oh. it'd be (import '(javax imageio))
22:47	notallama	er. no it isn't. i'm being dumb again.
22:47	notallama	it's the way you had it, but you need to list some classes after it.
22:47	notallama	so (import '(javax.imageio classname otherclassname))
22:49	hiredman	no
22:49	hiredman	yeah, import needs classnames
22:49	hiredman	(import '(javax.imageionolbatski)) means "import nothing"
22:50	hiredman	so it doesn't throw an error
22:50	hiredman	(import '(javax.imageionolbatski foo)) will throw an exception
22:58	nolbat	is there a way to doc javaclasses, like get constrcutors i have to check java documentation? for that?
22:59	notallama	http://java.sun.com/javase/6/docs/api/
23:05	hiredman	clojurebot: show
23:05	clojurebot	show is http://groups.google.com/group/clojure/msg/96ed91f823305f02
23:05	hiredman	show is a function someone wrote that can help you explore java classes
23:46	jshen	I'm not a java programmer. Can someone tell me why I get: java.lang.NoClassDefFoundError: jline/ConsoleRunner
23:46	jshen	when I try to run java -cp jline-0.9.91.jar;clojure.jar jline.ConsoleRunner clojure.lang.Repl
23:46	jshen	from the getting started page
23:48	jshen	typo, ; should have been :
23:48	jshen	doesn't work either way
23:48	hiredman	huh
23:49	hiredman	that is a weird error
23:50	hiredman	does clojure run fine without jline?
23:53	danlarkin	jshen: I've seen a few people report this error, I can't tell you why it happens but I can tell you they've had success switching to rlwrap
23:53	jshen	hiredman: yes, runs fine without it
23:53	jshen	danlarkin: thanks, i'll try that
23:54	danlarkin	it should probably be reported to the mailing list or something
23:58	jshen	i was assuming it was user error
23:58	jshen	some java classpath thing or something
23:58	jshen	i tried absolute paths for the jars, but that didn't work either