#clojure – 2009-01-12

2009-01-12

00:14	durka	does this function exist?
00:15	durka	(defn eval-in-ns [ns code] (binding [ns (the-ns ns)] (eval code)))
00:15	durka	(eval-in-ns 'kitchen '(make-coffee))
00:16	hiredman	clojurebot: latest?
00:16	clojurebot	latest is 1207
00:16	hiredman	svn rev 1207
00:16	clojurebot	svn rev 1207; intial import of streams stuff, Java side
00:16	hiredman	durka: I don't think so
00:20	Chouser	'eval' is generally frowned on. It's there because it needs to be for repls and the system itself to work, but not much effort is made to make it convenient.
00:54	dcnstrct	hrm... I want parenscript for clojure.
00:55	dhaya	dcnstrct: did you look at clojurescript in contrib?
00:55	dcnstrct	what ?! you're kidding me
00:55	dcnstrct	no I'll check it out
00:55	burkelibbey	http://github.com/kevinoneill/clojure-contrib/tree/master/clojurescript
00:56	dhaya	I don't think it is complete yet though.
00:56	burkelibbey	Nope
00:57	Chouser	dcnstrct: what do you want out of it?
00:58	dcnstrct	I want to use it together with a web serverl ike Jetty and JCouchDB for my persistance layer
00:58	dcnstrct	and kind of roll my own all lisp web framework
00:58	burkelibbey	Obvious question is "have you looked at Compojure?" ;)
00:59	Chouser	and you want to be able to write ajaxy event handlers in clojure and have them work in the browser?
00:59	dcnstrct	actually no I hated the name so bad ;)
00:59	dcnstrct	I'll go check it out
00:59	burkelibbey	haha, that was my reason for not looking at Webjure.
00:59	Chouser	or what role would clojurescript play?
01:00	dcnstrct	Chouser, well mainly I want to write a whole web app in lisp, so that means I'll want a DSL for generating XHTML and one for JS
01:00	dcnstrct	and hopefully the two would play nicely with eachother
01:01	Chouser	there are probably dozen libs that convert some style of clojure s-expr or other to x/html.
01:01	Chouser	there are even one or two clojure-to-json libs around
01:02	danlarkin	there sure are!
01:02	dcnstrct	that gets me pretty damn close then =]
01:02	Chouser	but if you actually want to produce javascript code from clojure-like sources, clojurescript can do it.
01:03	burkelibbey	With regard to just the html DSL, compojure seems to have this: http://github.com/weavejester/compojure/tree/master/src/compojure/html.clj
01:03	Chouser	I was rather excited about it for a while, but I'm starting to wonder just exactly how narrow the use cases are.
01:05	dcnstrct	Chouser, What I really want to do is I want to create a clojure DSL around a system called Open Laszlo. Open laszlo sources are just xhtml and JS, but they get compiled down to flash bytecode
01:05	Chouser	heh. clojure -> js -> flash?
01:05	dcnstrct	so that way I can write flash apps without having to endure ActionScript and or lots of pointy brackets
01:06	dcnstrct	clojure -> js/xml -> laszlo compiler -> flash=ORdhtml
01:06	Chouser	fascinating. I've heard of laszlo, but I wasn't aware it included js->flash
01:06	dcnstrct	yeah you program declaratively?sp? with an XML/JS based DSL
01:07	dcnstrct	and then the program can be compiled into either a JS app
01:07	dcnstrct	or a flash app
01:07	burkelibbey	That sounds really cool -- I may have to check that out.
01:07	dcnstrct	and it's all written in java too, so it may be clojure friendly
01:08	dcnstrct	=] thnx for the hep people.. checking out compujure and clojurescript. ttyl
02:28	joma	hmm coming back to python after using clojure just feels wrong
02:28	joma	its like clojure and haskell are just above everything else
02:32	banisterfiend	joma: yeah the local gay community has that as their slogan, are you sure you're not wearing a pink t-shirt and sitting on a dildo
02:37	Lau_of_DK	Morning all
02:38	Chousuke	morning
02:54	Chouser	clojure.main isn't pleasing me. I suppose I'll have to write up a whole thing as to why, if I want it to change.
02:55	Chouser	I feel bad I didn't test it and speak up earlier. :-/
02:55	Lau_of_DK	Clojure.main ?
02:56	Chouser	,(keys (ns-publics 'clojure.main))
02:56	clojurebot	java.lang.Exception: No namespace: clojure.main found
02:56	Chouser	hmph.
02:57	Chouser	it's meant to replace clojure.lang.Script and clojure.lang.Repl, I believe.
02:57	Chouser	I shouldn't be trying to talk -- it's too lat emand my brain's functioning quite as well as I think it is.
02:57	Chouser	I think I just replied to a google group post. I wonder if it made any sense.
03:54	danlei	does anybody know, what the new equivalent of slime-redirect-inferior-output is?
05:18	AWizzArd	clojurebot: max people
05:18	clojurebot	max people is 127
07:56	grosours	hi everybody
07:56	Lau_of_DK	Hey hey
08:13	vsthesquares	http://adiumx.com/blog/2009/01/msn-rejecting-adium-132-connections/
09:42	AWizzArd	I have a 2 line clojure file: line1: (ns 'my.file (:gen-class)) and line2: (defn foo [bt text] (.setText bt text)). I (compile) this to .class files and would like to call foo from Java.
09:44	AWizzArd	How can I load the contents of the .class files? And when this happened, how can I call foo?
09:46	cooldude127	AWizzArd: you can't call it from java
09:46	cooldude127	any functions defined on your class need to have a "0
09:46	cooldude127	"-" prefix
09:46	cooldude127	sorry typo
09:46	cooldude127	http://clojure.org/compilation
09:47	AWizzArd	oki
09:48	cooldude127	i'm not sure if or how you can define static methods on a class from clojure
09:51	Chouser	you can can use clojure methods to call clojure fns from java
09:52	Chouser	I suppose you'd start with a call to 'require' to load the namespace, and then you could fetch the Var for foo and invoke it
09:53	AWizzArd	What is the function to call Clojure functions with Clojure from Java?
09:53	Chouser	Instances of Var are invokable.
09:55	dhaya	AWizzArd: http://en.wikibooks.org/wiki/Clojure_Programming/Tutorials_and_Tips#Invoking_Clojure_from_Java
09:56	Chouser	take a look at src/jvm/clojure/main.java
09:57	AWizzArd	good, thanks
10:52	danlarkin	java is like python, in that if I (catch Exception...) any exceptions that inherit from Exception will be caught, right?
10:52	Chouser	yes
10:53	danlarkin	cool
10:53	Chouser	which is almost, but not quite, all of them.
10:53	danlarkin	of course
10:53	danlarkin	why wouldn't it be all
10:53	danlarkin	that would be too convenient
10:54	Chouser	if you really want all of them, use Throwable. But that's generally discouraged
10:59	danlarkin	I was planning on using mmcgrana's clj-backtrace to display exceptions through a web browser, to do that I'm assuming I'll have to catch everything and then deal with printing it to the browser
10:59	mmcgrana	danlarking: Throwables are either Errors or Exceptions, Exceptions are meant to be recoverable, Errors are usually meant to be fatal.
10:59	mmcgrana	danlarkin: very exciting release this evening on that front!
11:00	danlarkin	Ooo la la
11:02	danlarkin	Okay, so maybe it's better just to catch Exceptions then
11:03	mmcgrana	but yeah the basic idea would be to add a try/catch around the app, and when Exceptions bubbled out print the backtrace to your response body, using either (pst-str e) or a lower-level api to customize the output, as you'll see in the release.
11:05	mmcgrana	danlarking: yes Error = game over. subclasses are e.g. ThreadDeatha and VirtualMachineError
11:05	mmcgrana	ack keeping mispelling your name
11:05	mmcgrana	* I keep
11:09	danlarkin	haha everyone does
11:09	danlarkin	it's the "ing" muscle memory
11:09	mmcgrana	o yeah good point
11:10	Chousuke	it sometimes appears when talking about python too
11:17	mmcgrana	danlarkin: btw have you seen the new colorizing in clj-backtrace? http://img.skitch.com/20090112-qu36c7p478nbkt1e2knt2hch1g.jpg
11:18	danlarkin	I have, it's super great, I hope I can make it work over the web
11:21	danlarkin	I'm sure I can, I just haven't tried yet
11:38	Chouser	hm, clojurescript compiler in an applet works.
11:38	rhickey	cool
11:39	Chouser	this should make the browser-based repl more sane, since it won't have to ship code off to a server to be translated.
11:40	rhickey	yes, very neat
11:41	rhickey	so applets work ok in general?
11:41	Chouser	I've not gotten one to work on Mac yet, but that's hard for me to test.
11:41	rhickey	I'd love to figure that out, since only Macs here
11:42	Chouser	:-)
11:43	Chouser	there is a Mac in the house, but I don't get much time on it usually.
11:44	Chouser	So I may be able to make an attempt to track it down at some point.
11:45	rhickey	my cursory glance at the error makes me feel like it is just that when compiled something is protected/public, and thus wrapped by gen-class, that at runtime on the Mac JVM is less accessible
11:46	rhickey	I wonder if an :only option for gen-class would be useful
11:46	Chouser	but you got a trivial applet to load and init ok, right?
11:47	Chouser	oh, you only tried appletviewer, didn't you?
11:47	rhickey	Chouser: appletviewer
11:48	Chouser	I think durka was reporting my applets were working fine in the appletviewer even on Mac.
11:49	rhickey	I know (way back in the '90s) some applets were confused when read from the file system vs over the net, in browser
11:49	rhickey	but not the case here reading yours over the net
11:53	Chouser	at the moment I have the applet returning a PersistentArrayMap, but of course this is a different beast than clojurescript's PersistentArrayMap. This is weird to think about.
11:54	rhickey	heh, yeah, now you have Java and js on same side of the fence
11:55	Chouser	I suppose the functions in rt.js (like 'first', 'seq', etc.) could be made to interoperate with the Java objects.
11:59	rhickey	Chouser: once you have full Clojure engine on that side, you could implement simple interpreter for Clojure on Clojure (just to make things more confusing)
11:59	Chouser	yes, I'd thought of writing a clojure interpreter in clojure.
11:59	Chousuke	so wait what.
12:00	Chouser	that would at the very least be more fun than writing (and maintaining!) clojure.lang.RT in javascript.
12:00	Chouser	Chousuke: you can't have a applet the provides a full clojure repl currently, because to do that you need to load dynamic bytecode, which applets (and android devices) won't allow.
12:01	Chousuke	hm, right.
12:01	Chousuke	so you'd need an interpreter.
12:01	Chouser	but if you were to write an interpreter that examined clojure s-exprs and called the appropriate Java functions, then you could have a repl.
12:01	danlarkin	this is rife with opportunity for a "yo dawg I wrote clojure in clojure so you can eval while you eval"
12:02	Chouser	but since clojure can now be compiled to classes, you could write this interpreter in clojure
12:02	Chousuke	such an interpreter would be useful for the sandbox too I think.
12:03	Chouser	or go the route I started pursuing last night, which is to have the applet produce javascript and eval that in the browser.
12:03	rhickey	Chouser: a lot of simple expression support for an interpreter is done, given Compiler.Expression.eval()
12:03	Chouser	rhickey: is that used for anything currently? I've never quite understood why it's there.
12:04	rhickey	Chouser: some things at the repl still run through it - used to be a lot more, but now fast enough to rwap in fns/conmpile/run in order to ensure same semantics
12:04	StartsWithK	Chouser: you mean you can't have dyamic bytcode in applet? like, clojure can't compile .clj on the fly inside the applet?
12:04	Chouser	huh. ok.
12:04	Chouser	StartsWithK: right.
12:05	StartsWithK	Hmm
12:05	rhickey	but essentially, almost all of Clojure except fns can be eval'ed like that
12:05	StartsWithK	i had opengl gears demo in clojure running in applet like 4-5 months ago
12:06	StartsWithK	you can denerate dynamic bytecode inside applet
12:06	Chouser	StartsWithK: ah, yes, I should be more specific. I'm talking about applets without lowered security barriers, that is, unsigned applets.
12:06	StartsWithK	gnerate*
12:22	StartsWithK	Chousuke: what is the main problem? That you have to give AllPermissions to your applet? Could that be solved by using RuntimePermission and restricting your applet so it can only generate bytcode in safe packages?
12:23	Chousuke	I don't think it needs AllPermissions, but the problem is that it needs any permission
12:24	Chousuke	it would be useful to just be able to run unsigned clojure code in an applet.
12:25	StartsWithK	sorry, Chouser*
12:34	ole3	is there a mapping between namespaces?
12:35	ole3	I have a ns foo-bar and this seems to get mapped to foo_bar
12:35	ole3	when i load the package
12:36	technomancy	I think it's just the dash-underscore translation.
12:36	technomancy	that one allows you to work around a limitation of the JVM
12:37	ole3	hm, so i have to name my directories with underscores
12:37	ole3	to load it i mean?
12:37	technomancy	afaik the only rule is any dashes in namespace names need to be underscores on disk, yeah
12:38	technomancy	but that applies to files and directories
12:38	ole3	so it is better not to use dashes in namespaces?
12:38	technomancy	if you have two-word namespaces, you should separate them with dashes.
12:39	technomancy	but if you can use one-word for each part of the namespace, that's fine too. =)
12:39	ole3	thank you
13:18	danlarkin	OT but really good post, http://groups.google.com/group/microsoft.public.sqlserver.programming/msg/6d61dbf80d6f0fb6
13:19	Chouser	I think rather than renaming rest to tail and adding a new function rest, it might be better to introduce a new fn to encapsulate the idiom: 'has-rest' or something.
13:19	Lau_of_DK	Good evening gents
13:20	danlarkin	Afternoon Lau
13:20	danlarkin	Chouser: "rest?"
13:21	Chouser	danlarkin: sure, something like that. I think it would be unnecessarily tricky to keep 'tail' and 'rest' straight.
13:21	Lau_of_DK	Chouser: Was any decicision made on nil punning yesterday?
13:22	Chouser	Lau_of_DK: not that I know of.
13:22	Lau_of_DK	Ok
13:22	danlarkin	wouldn't it be most common to use rest, though? I mean to say that 'tail' would have limited usage in user code, right?
13:24	gnuvince_	,(time (dotimes [_ 10000] (last (sort (range 1000)))))
13:24	clojurebot	"Elapsed time: 5648.104 msecs"
13:24	gnuvince_	,(time (dotimes [_ 10000] (reduce max (range 1000))))
13:24	clojurebot	"Elapsed time: 322.303 msecs"
13:24	cooldude127	well then
13:24	cooldude127	that's good to know
13:25	Chouser	reduce max is linear vs nlogn for sort. But the real difference probably comes from sort putting the whole seq into an array and then calling Java's sort.
13:25	gnuvince_	There's a WTF on reddit about "how to find the largest element without looping" and some people are saying things like "well if the sort routine is written in C..."
13:26	danlarkin	,(time (dotimes [_ 10000] (first (sort > (range 1000)))))
13:26	clojurebot	"Elapsed time: 8490.771 msecs"
13:26	cooldude127	wow a big pile of suck
13:27	danlarkin	max it is
13:27	cooldude127	lol
13:28	danlarkin	gnuvince_: yeah I saw that thread... ridiculous
13:28	Chouser	,(time (dotimes [_ 10000] (apply max (range 1000))))
13:28	clojurebot	"Elapsed time: 799.461 msecs"
13:28	gnuvince_	danlarkin: yes.
13:28	Chouser	,(time (dotimes [_ 10000] (apply max (range 1000))))
13:28	clojurebot	"Elapsed time: 277.883 msecs"
13:28	cooldude127	wtf?
13:28	Chouser	,(time (dotimes [_ 10000] (apply max (range 1000))))
13:28	clojurebot	"Elapsed time: 297.532 msecs"
13:29	Chousuke	must've been some glitch :)
13:29	danlarkin	nah, second run is always way way faster
13:30	danlarkin	I'm thinking it's some jvm optimizing going on profiling the first run and using it on subsequent runs? but really I have no idea
13:30	Chouser	much of the time 'apply foo' is essentially the same as 'reduce foo', but if one of them is going to be faster, it'll be 'apply foo'
13:30	Chousuke	especially true for str I guess
13:31	Chouser	Chousuke: right, that's the main example. but the point is that foo is control of the loop when you 'apply foo', so it can do the best/smartest thing
13:31	Chousuke	,(time (do (reduce str (range 1000)) nil))
13:31	clojurebot	"Elapsed time: 12.906 msecs"
13:31	Chouser	with 'reduce foo' you're controlling the loop. 'foo' only sees 2 args at a time, and so can't do anything clever.
13:31	Chousuke	hmm, quick?
13:32	Chousuke	or maybe it noticed the result is nil and skipped the reduce :)
13:32	danlarkin	but try the apply :)
13:33	danlarkin	,(time (do (apply str (range 1000)) nil))
13:33	clojurebot	"Elapsed time: 2.027 msecs"
13:33	Chouser	I told you, Clojure's alrady too fast.
13:33	Chousuke	ah right, maybe I should've added a dotimes to that :P
13:36	rhickey__	note that while it is true (apply foo x) let's foo decide the best course, (reduce foo x) let's x decide, if it has optimized reduce vs. seq navigation
13:36	rhickey__	lets
13:36	rhickey__	aargh
13:36	rhickey__	irc is destroying my English
13:36	danlarkin	clojure is destroying my python, serves you right!
13:37	Lau_of_DK	hmm... Clojure destroys Python... i like :)
13:37	kotarak	hehe :)
13:38	danlarkin	you guys and your python hating... psh
13:42	durka	rhickey_: what do you mean by optimized reduce vs. seq navigation?
13:42	durka	do you mean if it is lazy?
13:44	rhickey__	durka: apply requires x be supplied to foo as a seq, reduce may hand foo to x for more efficient internal iteration
13:45	Chouser	,(let [x (map identity (range 1000000))] (time (reduce + x)))
13:45	clojurebot	499999500000
13:46	clojurebot	"Elapsed time: 1671.362 msecs"
13:46	Chouser	,(let [x (range 1000000)] (time (reduce + x)))
13:46	clojurebot	499999500000
13:46	clojurebot	"Elapsed time: 318.357 msecs"
13:47	rhickey__	Chouser: range may be a bad candidate as it optimizes both seq and reduce
13:47	Chouser	,(let [x (vec (range 1000000))] (time (reduce + x)))
13:47	clojurebot	499999500000
13:47	clojurebot	"Elapsed time: 238.569 msecs"
13:48	rhickey__	as a general rule I would say prefer reduce, except for str, as 1 str of n things is more efficient than n-1 strs of 2 things
13:48	Chouser	but if you use 'apply +', + will turn around and use reduce so you're still covered.
13:50	rhickey__	Chouser: still, prefer reduce, it will engender good habits and ways of thinking about things, apply is just for when you have the args for a single call in a seq already
13:52	Chouser	yessir
13:55	rhickey__	Sorry, didn't mean to be pedantic, just working on lfe/streams stuff and wondering if people really get reduce, since they'll need to
13:59	Chouser	I guess I should have said "ok" if I didn't want to sound injured. No need to apologize.
13:59	Chouser	is reduce any harder to get than map?
14:00	rhickey__	I see lots of loop/recur where reduce would do
14:00	Chouser	ah, I see.
14:01	burkelibbey	People usually seem to have a little more trouble "getting" reduce.
14:02	rhickey__	for all those following yesterday's stream conversation, unification is definitely out. Just too much of a mismatch to have map be pure on seqs and mutating on streams
14:02	burkelibbey	So that means... nil punning stays, right?
14:02	Chouser	I wonder if 'reduce' could be rolled into 'for' somehow. People unfamiliar with functional programming seem to be more comfortable with 'for' at least at first.
14:03	Chouser	(for [i (range 10) :reduce +] ?)
14:04	rhickey__	burkelibbey: nil punning safe for now, but as I said yesterday, fully lazy seqs are independent of streams, but unification would have allowed both
14:04	Chouser	(for [i (range 10) :reduce (+ i old-i?)] ?)
14:05	rhickey__	:)
14:06	technomancy	was a decision reached on whether streams would be in 1.0 or not?
14:07	rhickey__	technomancy: I need to figure out if they require any breaking changes
14:10	technomancy	gotcha. just curious; I don't feel strongly either way.
14:10	Chouser	(for [i (range 10)] (+ i (previous i 0))) is so much easier to understand than (reductions + 0 (range 10)) :-P
14:13	rhickey__	Chouser: http://www.lispworks.com/documentation/HyperSpec/Body/06_ac.htm
14:15	rhickey__	http://www.lispworks.com/documentation/HyperSpec/Body/m_loop.htm
14:15	rhickey__	when you're ready to go really crazy with for
14:15	Lau_of_DK	I miss that loop :)
14:15	rhickey__	Lau_of_DK: not coming any time soon, loop is probably more complex than all of Clojure!
14:16	Chouser	no thank you.
14:16	Lau_of_DK	hehe, really? thats surprising... I also remember using it while relying heavily on sideeffects
14:17	technomancy	it's a good example of how you can do pretty much anything in Lisp syntax, but it's also a good example of why restraint in such an endeavor is important.
14:17	danlarkin	isn't there a project on github implementing LOOP in clojure? I might be wrong though, since I can't find it..
14:17	Lau_of_DK	rhickey__: I think you made a really good point about nil punning yesterday, are you looking to implement the proposed changes anytime soon ?
14:18	danlarkin	oh, nevermind, I'm thinking of FORMAT :)
14:18	Chouser	Lau_of_DK: 14:02 < rhickey__> for all those following yesterday's stream conversation, unification is definitely out. Just too much of a mismatch to have map be pure on seqs and mutating on streams
14:18	rhickey__	Lau_of_DK: there are no proposed changes yet, just wanted to see how people felt about it
14:18	Lau_of_DK	danlarkin: If you ran loop in something like SBCL, and stored all the results and calculations in an SQL table, then technically ClojureQL could be the project your looking for :)
14:18	Lau_of_DK	rhickey__: ok... just sounded interesting
14:18	Lau_of_DK	Chouser: thanks
14:19	joma	deos clojure have arrays or I use ajava arrays then? if i wanted to write a matrix-lib in clojure(just for fun I kno there a re good java ones), what would I use? vectors of vectors? vectors dont have O(1) access right? would I use dicts?
14:19	Chouser	Lau_of_DK: but there's a branch in svn for the streams stuff, if you want to play with it.
14:19	Lau_of_DK	cool
14:19	gnuvince_	joma: vectors have O(log32 n) random access
14:19	gnuvince_	Which is pretty good
14:20	gnuvince_	,(/ (Math/log 1e10) (Math/log 32))
14:20	clojurebot	6.643856189774725
14:20	Chousuke	maybe not acceptable for a matrix lib though
14:20	Chouser	how big would your matrix be!?
14:21	Chouser	vectors are more "fun" in clojure than java arrays are.
14:22	rhickey__	Chouser: streams branch not ready for use yet
14:22	Chouser	ok
14:22	rhickey__	only about 1/3 is up
14:22	rhickey__	some Java stuff, no clj stuff
14:23	Chousuke	Chouser: sometimes you have really huge matrices :)
14:24	Chousuke	but I'm sure there are plenty of high-performance java matrix packages
14:26	rhickey__	http://piotr.wendykier.googlepages.com/parallelcolt
14:26	rhickey__	http://acs.lbl.gov/~hoschek/colt/
14:27	Lau_of_DK	rhickey__: Since your so informed about anything relating to software developement, I need to ask: Do you have a favorite bug tracker? :)
14:28	technomancy	though of course that is hard to maintain. =)
14:28	Lau_of_DK	Its a little hard, yes :)
14:28	rhickey__	technomancy: I agree, and it was with trepidation I introduced: http://code.google.com/p/clojure/issues/list
14:29	Lau_of_DK	Especially when a bug can be anything from "Your software ate my cat" to "This line needs to be moved up 1 pixel"
14:29	technomancy	man, if clojure could eat cats that would be awesome.
14:29	Lau_of_DK	haha
14:29	Lau_of_DK	My friend, I think you missed the point
14:30	Chouser	I think I've been proved wrong about the issues page being overrun, though.
14:30	Chouser	which is good.
14:30	technomancy	I do love how short the issue list is.
14:31	technomancy	seems like a good balance of bugs and enhancements
14:31	technomancy	"Clojure is the least-buggy lisp implementation ever! Only sixteen bugs."
14:32	technomancy	actually... none of the high-priority defects are even bugs.
14:33	kotarak	Some are also just documentation issues.
14:33	kotarak	Which rules me out, I guess.
14:33	Chouser	and some are fixed, with patches waiting patiently to be applied. :-)
14:34	Lau_of_DK	Can we consider it a bug that ClojureQL is not included in Core yet, or do I need to post that somewhere else?
14:35	Chouser	heh
14:38	Lau_of_DK	ehh.. I made a funny? Not intentional I assure you :)
14:46	Chousuke	Looking at the stream code makes me wish java had macros. and I'm not even writing that code :D
14:50	joma	thats interesting. for real only 16bugs? how many does a language normally have? take python for example, or sbcl or Java or C++?
14:52	technomancy	joma: that's not really a good question to ask... for instance, many of Java's bugs will be inherited by Clojure, and C++ can't have any bugs since it's not an implementation, just a language standard.
14:52	technomancy	actually, I take that back, C++ has tons of bugs even without being software.
14:52	technomancy	arguably its entire existence
14:52	danlarkin	and python's been around for 18+ years, and clojure only ~3
14:53	danlarkin	two of which were unreleased
14:53	Chouser	also, that's a list of discovered but unfixed bugs. It says nothing about how many there were that have been fixed, and certainly not how many undiscovered bugs there may be.
15:08	joma	for(r=0; r<rows; r++) { for(c=0; c<columns; c++) {mtrx[r][c] = new_matrix[r][c];}} , why is that not working?
15:08	joma	sorry wrong channel
16:03	Lau_of_DK	How does if-let work ?
16:04	drewr	Lau_of_DK: (if-let [foo true] foo :else) => true
16:04	drewr	(if-let [bar false] foo bar) => false
16:05	Lau_of_DK	(if-let [x (= 2 2)] x 5)
16:05	Lau_of_DK	so x will be true and the rest is like a normal if then..
16:06	drewr	It binds the symbol if the value is true(-ish).
16:06	kotarak	Lau_of_DK: it's more interesting for things like (if-let [rst (rest of-a-seq)] (map stuff rst) ["The seq did not have a rest"])
16:06	drewr	It's the same as (if :foo (let [x :foo] ... ))
16:07	drewr	Er, (if :foo (let [x :foo] ... ) ...)
16:07	drewr	The other one was more like when-let.
16:08	Lau_of_DK	ok, thanks guys
16:23	Chouser	ha! clojurescript destructuring works on java clojure vectors.
16:34	danlarkin	Chouser: sweeeet
16:37	Chouser	it's goofy, but it was working already. vector destructuring calls clojure.nth
16:38	Chouser	clojurescript's nth looks to see if the object has an nth method. The Java vector object does. So it gets called, pulls the value from the java object, and returns it through the javascript.
16:38	Chouser	destructuring that assigns that to a local javascript variable, and you're off and running.
16:50	Chouser	no new macros in a browser repl, though.
17:04	herkel	maybe im stupid but ic ant figure out the damn classpath, i have it working in clojure but in java i dnt get it. C:/javaprogs/Matrix/ , in there I have Matrix.java and MatrixTest.java. what should MatrixTest inherit and what package name should Matrix.java be in? wht should I pass as classpath when I compile?
17:05	kotarak	If C:/javaprogs is in your classpath, I would suspect Matrix to be in the package matrix.
17:05	kotarak	package matrix;
17:05	kotarak	public class Matrix ......
17:06	kotarak	It's similar to Clojure. The package is the path to the file. The class (or in clojure: the last part of the namespace) is the file.
17:07	kotarak	package foo.bar; class Baz ... <=> foo/bar/Baz.java
17:09	Raynes	I wish I could find an open source pastebin that supported clojure =\
17:11	Raynes	Oh.
17:11	Raynes	Found one.
17:11	Raynes	:D
17:20	kotarak	Raynes: would you share your success?
17:23	Raynes	kotarak: Lodgeit is open source.
17:23	Raynes	It also supports Haskell, just what I needed.
17:23	Raynes	http://dev.pocoo.org/projects/lodgeit/
17:24	Raynes	paste.pocoo.org
17:24	kotarak	Indeed. Clojure support available...
17:25	Raynes	I knew about Lodgeit, but I didn't know it was open source.
17:26	Chousuke	that's pretty nice.
17:26	Raynes	Agreed.
17:26	Raynes	I'm going to slap it on my site :>
17:27	Chousuke	the rest of the utils look nice too
17:28	kotarak	And there is a Vim plugin for pasting...
17:28	danlarkin	I use werkzeug with django, it's very helpful
17:30	Raynes	Dirty vimmers.
17:30	craigmarshall9	:-D
17:38	durka	is (in-ns (ns-name ns)) the same as (set! ns ns) ?
17:39	durka	and (binding [ns ns] ...)?
17:41	Fib	Are "symbols" in Clojure/LISP just another name for "identifier", or is there a difference? I have a feeling there is but I've not been able to pin it down from what little I know of LISPs.
17:41	durka	the documentation of in-ns seems to suggest that it would be, and i can't find an implementation, except one in java that seems to just call (set! ns)
17:42	durka	Fib: there is a difference, but i think there is also a difference between a clojure symbol and a lisp symbol
17:42	durka	but i am fuzzy on all three definitions as well
17:43	Chouser	Fib: My common lisp knowledge is weak, but I think there a "symbol" may have storage, so it's more like a variable.
17:43	technomancy	Fib: they're used mostly for identifiers, yes
17:44	technomancy	symbols are usually bound to a value, but sometimes they're used by themselves to just be disconnected names
17:44	Chouser	Fib: In Clojure a symbol is an object -- it has data members for namespace and name, each of which is a string. It's essentially a special kind of string.
17:44	rhickey__	More naming fn, given bifurcation, what suffix for stream versions of fns like map/filter/reduce? Candidates are map! and map$
17:44	rhickey__	fun
17:45	Chouser	'map!' doesn't change the value of the stream it's consuming, right? just generates a stream that's doing mutation internally?
17:46	rhickey__	Chouser: it does change the state of the stream, streams are inherently stateful, each call to next! eats a value
17:47	rhickey__	that's the main reason not to unify with map of seqs
17:47	Chouser	ok, right, sorry.
17:48	Chousuke	hmm, you have many edits to clojure.core in your clojurescript compatibility patch :/
17:48	Chouser	you don't want to consider a suffix of "+"?
17:48	rhickey__	sometimes it will be a "real", io type mutation, like a file based stream, other times a weaker mutation of a cursor on a persistent data structure
17:48	Chouser	Chousuke: yes, and also RT.java
17:48	rhickey__	would consider anything, throwing it out for suggestions
17:49	rhickey__	a benefit of non-alpha is that you could stick it on any existing name
17:50	Chouser	I like the idea of a new suffix that does already mean more generally "mutate" like "!", but I find $ rather unattractive.
17:50	durka	i kind of like $ because it suggests S for stream
17:50	durka	on the other hand it has an overloaded java meaning
17:50	kotarak	why not mapS, then?
17:50	rhickey__	durka: right, that's the argument for it
17:50	kotarak	$ is ugly
17:50	Chouser	look, a stream between two rocks: %
17:50	rhickey__	but people hate $
17:51	rhickey__	Chouser: heh
17:51	danlarkin	map?
17:51	kotarak	maps
17:51	kotarak	mapEUR ;)
17:51	Chousuke	:P
17:52	rhickey__	ascii please :)
17:52	Chousuke	I guess map: would be too unnoticeable.
17:52	kotarak	map>
17:52	kotarak	map<
17:52	Chousuke	and looks like a keyword or some kind of label anyway
17:52	Chouser	(reduce% #(- %2 %) strm)
17:53	kotarak	We are approaching Haskell, eh?
17:53	rhickey__	kotarak: not even close
17:53	durka	weren't you considering map* earlier?
17:54	durka	* seems to be the historical lisp character for "subtly different version"
17:54	kotarak	map�, but not ascii....
17:54	Chousuke	map\|, but a bit difficult to type :/
17:54	Chousuke	(needs alt on my keyboard)
17:55	kotarak	map-
17:55	danlarkin	there's no good answer :-/
17:55	rhickey__	just FYI, all of these versions will curry, so that hairy Haskell LFE stuff becomes something like this:
17:56	rhickey__	(line-streamer rdr (comp-> (map! inc) (filter! even?) (reduce! + 10)))
17:56	rhickey__	not that it makes sense reduce lines with + :)
17:56	rhickey__	comp-> is like comp in reverse order
17:57	rhickey__	so something like line-streamer can fully encapsulate the use of its resource-based stream
17:57	Chousuke	is it required that they curry like that? or just optional?
17:57	kotarak	Wasn't there a longer discussion about currying before?
17:57	Chousuke	I guess it's just adding an overload without the seq/stream argument
17:58	rhickey__	Chousuke: you want to say partial a lot?
17:58	Chousuke	not really.
17:58	Chousuke	that looks good.
17:58	rhickey__	Chousuke: right, just an arity overload
17:58	karmazilla	did you also change your mind on currying for normal map, filter, reduce?
17:59	rhickey__	karmazilla: nope, these might actually be used curried more often than not
18:00	Chousuke	would it break anything to add similar overloads for the regular seq functions though?
18:01	rhickey__	I would like not to get distracted by that now
18:01	Chousuke	okay, so back to naming... hm.
18:02	Chousuke	I think I find ! the least offensive. maybe users could be re-educated to just think it means "pay attention!"
18:02	Chousuke	since streams are lossy.
18:02	danlarkin	so there's set! (which means side effect) and map! (which means consumes-a-stream)
18:03	danlarkin	which I guess are similar ideas
18:03	rhickey__	danlarkin: yes, because it consumes a stream by side-effect
18:03	danlarkin	yeah
18:04	rhickey__	the thing is, when you package them up as in the line-streamer call above, they become safe(r)
18:06	danlarkin	see this is where haskell is nice, because with the type system you can say hey! you can't use these things where you're not expecting side effects
18:06	danlarkin	that's my understanding, anyway
18:06	rhickey__	danlarkin: yeah, by tainting your entire call chain
18:07	karmazilla	as Erik Meijer would have said; "but it's the truth!" :)
18:08	rhickey__	right now I've got it so io! blocks and transactions can't overlap, will be interesting to see how far that gets us
18:08	rhickey__	karmazilla: its a straightjacket that keeps you from painting outside the lines (and makes it difficult to play tennis)
18:09	karmazilla	hehe yeah. He also said he liked dynamic languages because if the type system tells you nothing, then it can't lie
18:10	rhickey__	karmazilla: there you go
18:11	technomancy	I don't see how the type system enforcing safety is any safer than using io! blocks.
18:11	technomancy	for side-effects, I mean
18:11	rhickey__	technomancy: type system can prove things at compile-time, all I can do is throw at runtime
18:12	technomancy	ah, so it just encourages you to spend less time on your test suite then... awesome. =)
18:13	karmazilla	and more time trying to get your code to compile
18:13	technomancy	if you've got a codebase that could sneak an io! block into a transaction without getting caught by your test suite, retrying side-effects is the least of your worries.
18:13	danlarkin	I think we can all agree that clojure should remain dynamically typed :)
18:14	technomancy	danlarkin: sometimes the choir enjoys a good sermon. =)
18:15	rhickey__	so, map!, map-> ???
18:16	danlarkin	map<- is too ugly I guess...
18:16	kotarak	just map<
18:17	danlarkin	yeah map< might do
18:17	karmazilla	I like map!
18:17	rhickey__	(comp (reduce<< + 10) (filter<< even?) (map<< inc))
18:17	Chousuke	reminds me of C++ :P
18:18	durka	i think that's too many characters
18:18	technomancy	map! appeals to /me
18:18	rhickey__	<< implies motion that < does not, for me
18:19	kotarak	we also have :>> in condp
18:19	rhickey__	that's right
18:20	danlarkin	naming is always the hardest part of programming... the rest is, what'd Chouser call it? SMOP?
18:20	technomancy	heh; my IRC client wraps nicks in <>s, so that makes this even more punctuationtastic.
18:20	technomancy	emoticon-oriented-programming
18:26	rhickey__	gotta run - thanks for the feedback
18:32	joma	I like ! like in Scheme I already use it myself
19:26	rhickey__	My slot at ILC 2009 has been confirmed - a full-day tutorial: Clojure in Depth
19:27	technomancy	what's ILC?
19:27	technomancy	International Lisp Conference?
19:27	rhickey__	yup
19:28	technomancy	cool!
19:28	rhickey__	http://www.international-lisp-conference.org/2009/index
19:29	technomancy	is it in cambridge every year?
19:29	rhickey__	no, moves around, and every 2 years
19:30	technomancy	I'll have to wait for a west coast one. Sounds like fun though.
19:30	rhickey__	I'll also be on a panel at ILC
19:30	rhickey__	2 slots at QCon London
19:31	rhickey__	And 2 irons in the fire for Java One, one talk and one panel, don't know on those yet
19:34	durka	will these be videotaped?
19:35	rhickey__	durka: I don't know, QCon seems very good about that, I'm also doing an interview with InfoQ while I'm there
19:39	Chouser	bleh. FnExpr.parse() calls compile, which demands a dynamic classloader.
19:41	durka	whoops... i tried to install enclojure, and now i have an unbootable netbeans
19:58	danlarkin	Hmmm
19:58	danlarkin	boston for a weekend
20:00	danlarkin	is there a cost for attending?
20:11	rhickey__	danlarkin: they do charge for the conference, I think in the past you could pay per day
20:14	technomancy	what's ballpark range on the cost?
20:15	danlarkin	oh gosh, in 2007 per diem was �150
20:16	technomancy	what city?
20:16	danlarkin	Cambridge, MA -- across the river from boston
20:17	danlarkin	or is it a bay at that point... I don't know
20:18	danlarkin	here's what I'm looking at http://www.international-lisp-conference.org/2007/price-list
20:19	technomancy	~USD500 for a weekend is not too horrible for a big event like that
20:20	technomancy	that's only slightly higher than RubyConf, which is pretty small.
20:20	technomancy	and not in Cambridge
20:20	danlarkin	much higher than pycon :-/
20:21	technomancy	well, I suspect they don't have a lot of big sponsors.
20:21	technomancy	ITA can only throw so many dollars at Lisp; someone else needs to step up. =)
20:23	danlarkin	yeahhh, pycon was a little sponsor-heavy last year
20:50	duderdo	Hello!
20:51	duderdo	How do I add entries to my classpath?
20:53	durka	depends on operating system
20:54	durka	generally has to do with the environment variable $CLASSPATH
20:54	durka	or you can use command line args to java
20:54	duderdo	I see, I'm using linux so I just need to make an environment variable?
20:58	durka	yeah
20:58	durka	if you want to make it permanent put it in your ~/.bashrc
20:58	durka	$CLASSPATH is directories separated by :
20:58	duderdo	So I need to update it each time I want to add a library I guess...?
21:04	durka	sorry i wasn't paying attention
21:04	durka	generally yes
21:04	durka	unless you can put the libraries in the same directory and just put the directory on the classpath
21:05	duderdo	No worries. Thanks man.
21:06	durka	if you're looking for references, you can find tons of classpath advice for java, and it all applies
21:10	duderdo	ah that's a good point
21:10	duderdo	will do. thanks again
21:21	herkel	im doing compressions algorithms for sparce matrices(seminoobish as i am dont count one smething revolutionary :) ). I ws thinking how dynamic typing can save a lot of memoery it seems. since you can choose freely how to represent while a static language(at least the ones that exist) forces you to organize ina certain way. is this correct?
21:47	herkel	im doing compressions algorithms for sparce matrices(seminoobish as i am dont count one smething revolutionary :) ). I ws thinking how dynamic typing can save a lot of memoery it seems. since you can choose freely how to represent while a static language(at least the ones that exist) forces you to organize ina certain way. is this correct?
21:49	Chouser	I don't think that's a valid generalization.