#clojure – 2009-08-20

2009-08-20

00:00	lowlycoder	procrastinate by helping me get work done
00:00	lowlycoder	and the cosmic balance is maintained
00:00	hiredman	lowlycoder: http://clojure.org/data_structures
00:01	lowlycoder	sounds like I want refs :-)
00:01	r2q2	IRC is for idleing I thought everyone knew that.
00:01	derrida	r2q2: +1
00:05	lowlycoder	are the items in a let expression guaranteed to be bound sequentially?
00:05	lowlycoder	(they must be, in order to allow a latter one to refer to a former one, right?]
00:07	rlb	lowlycoder: (doc let), follow link, second sentence (and yes).
00:08	rlb	,(doc let)
00:08	clojurebot	"([bindings & body]); Evaluates the exprs in a lexical context in which the symbols in the binding-forms are bound to their respective init-exprs or parts therein."
00:08	rlb	Hmm, mine says: Please see http://clojure.org/special_forms#let
00:09	lowlycoder	is it just me, or is clojure code much much more dense than lisp code?
00:13	hiredman	let isn't really a special form, let is a macro that emits a call to let, and let is a special form
00:13	hiredman	one of the utility functions doc uses is hardwired to treat let as a special form
00:14	hiredman	but clojurebot's doc is not, so it can actually return the docstring from the let macro
00:14	lowlycoder	you are very knowledgable
00:14	lowlycoder	if I had a startup, could I hire you?
00:15	lowlycoder	the thing that surpises me with let and destructuring binding
00:15	lowlycoder	is that I can often times write entire functions in a let declaration body
00:21	hiredman	lowlycoder: well, maybe you should destructure in the function args and leave out the let
00:21	lowlycoder	nah; i need the sequential binding o th elet
00:29	lowlycoder	argh , -> ~ is so stupid, ',' is so easy to type, just using middle finger; ~ is so awkwaaard to type, using pinky on shirt + ring finger for ` ... wtf
00:32	lowlycoder	user=> (.printStackTrace *e)
00:32	lowlycoder	java.lang.NullPointerException (NO_SOURCE_FILE:0)
00:32	lowlycoder	how can I get more info thatn that?
00:32	lowlycoder	the line above it is a bunch of *.java files and a ... oh wait, I see a model.clj file
00:32	lowlycoder	that looks like my fault
00:40	lowlycoder	how do I read the value out of a ref?
00:40	lowlycoder	not the @ notation
00:40	lowlycoder	the actual function
00:41	lowlycoder	deref
00:41	lowlycoder	thanks
00:45	hiredman	,(macroexpand '@foo)
00:45	clojurebot	(clojure.core/deref foo)
00:45	lowlycoder	that is smart
01:14	lowlycoder	is \ used much in clojure?
01:14	lowlycoder	i want to remap it to ~
01:14	lowlycoder	since I use that alot
01:16	lowlycoder	can anyone hear me?
01:16	hiredman	\ is used for characters
01:16	hiredman	,\a
01:16	clojurebot	\a
01:17	lowlycoder	how about one of !@#$%^&* ?
01:17	lowlycoder	@ is for deref, ! used for anything?
01:17	lowlycoder	* is probaly used for multiply
01:20	hiredman	you cannot chaning the meaning of \ without cracking open the reader
01:21	hiredman	which will make your code incompatible with everyone elses
01:21	lowlycoder	oh, i was going to remap it in vim/xmodmap
01:21	lowlycoder	so it'll still look like ~
01:44	Fossi	what's ^ used for? or $?
01:45	hiredman	,(macroexpand '^foo)
01:45	clojurebot	(clojure.core/meta foo)
01:45	hiredman	,(macroexpand '$foo)
01:45	clojurebot	$foo
01:45	hiredman	nothing
01:46	Fossi	ah, right meta
02:51	demas	Hi, all. I'm read 'Programming Clojure' on page 174 and I'm trying the example 'male_female.clj'
02:51	demas	But I get error message: => (m 10) -
02:51	demas	• Игра с нулевой суммой - если один игрок выигрывает то, что проигрывает другой.
02:51	demas	• Ход - выбор одного из предусмотренных правилами игры вариантов.
02:51	demas	• Личный ход - сознательный выбор (в отличии от случайного хода)
02:52	demas	• Игра с полной информацией - игрок при каждом личном ходе знает результаты всех предыдущих ходов, как личных, так и случайных.
02:52	demas	• Конечной называется игра, если у игрока есть конечное число стратегий.
02:52	demas	sorry
02:52	demas	java.lang.IllegalArgumentException: Wrong number of args passed to: user$m (NO_SOURCE_FILE:0)
02:52	demas	Here is source code:
02:52	dulanov	@demas жги чувак )
02:52	demas	(declare m f)
02:52	hiredman	demas: use a pastbin
02:53	demas	(defn m [n]
02:53	demas	(if (zero? n)
02:53	demas	0
02:53	demas	(- n (f (m dec n)))))
02:53	demas	(defn f [n]
02:53	demas	(if (zero? n)
02:53	demas	1
02:53	demas	(- n (m (f (dec n))))))
02:53	hiredman	sigh
02:53	hiredman	lisppaste8: url
02:53	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
02:54	demas	ok
02:54	demas	http://pastebin.com/m5cde0ed6
02:55	hiredman	you are missing some parens
02:57	demas	yes, i see
02:57	demas	thank you
03:13	LauJensen	Top of the morning gents
03:13	LauJensen	~clojurebot where are you ?
03:13	clojurebot	http://github.com/hiredman/clojurebot/tree/master
03:43	AWizzArd	hiredman: still awake?
03:43	hiredman	yessir
03:44	Raynes	AWizzArd: A real hacker never sleeps. Especially a Lisp hacker. And especially ones named hiredman.
03:44	AWizzArd	did you try out fnparse?
03:44	AWizzArd	Raynes: true, hired is the most awakest guy in here g
03:44	hiredman	snort
03:45	hiredman	you mean update clojurebot to work with the latest fnparse?
03:45	hiredman	(I haven't)
03:46	AWizzArd	you could teach the clojurebot to count parens for everything that gets posted here, and if it detects missing parens it could tell the user.
03:46	hiredman	:(
03:47	AWizzArd	with the exception of smilies
03:47	hiredman	AWizzArd: I'd rather code was pasted to a pastebin then to the channel
03:48	AWizzArd	also an option
03:50	hiredman	http://delicious.com/clojurebot/pastbin
03:57	Fossi	sure it's not tiredman?
03:59	hiredman	:/
06:54	hamza	hey guys, how can i remove an element from a vector at a certain
06:54	hamza	index?
07:22	mtd	clojurebot: ,(assoc [0 1 2 3 4] 2 :two)
07:22	clojurebot	Gabh mo leithscéal?
07:22	mtd	,(assoc [0 1 2 3 4] 2 :two)
07:22	clojurebot	[0 1 :two 3 4]
07:23	mtd	hamza: ^^
07:26	ole3	,subvec
07:26	clojurebot	#<core$subvec__4942 clojure.core$subvec__4942@fb53f6>
07:27	Chousuke	hamza: you can overwrite it but actually removing it requires rebuilding most of the vector.
07:27	Chousuke	hamza: though if it's near the end it'll be reasonably cheap :)
07:28	rottcodd	,(let [v [0 1 2] i 1] (reduce conj (subvec v 0 i) (subvec v (inc i) (count v))))
07:28	clojurebot	[0 2]
07:29	ole3	,(let [v [0 1 2 3] i 2] (vec (concat (subvec v 0 i) (subvec v (+ i 1)))))
07:29	ole3	+
07:29	clojurebot	[0 1 3]
07:31	Chousuke	that's O(n) though, and creates an entirely new vector.
07:32	Chousuke	though I guess the first one is O(n) too, technically :P
07:36	ole3	yes
08:36	Fossi	i'm looking for a contrib function that groups maps according to a function. can't find it. somebody know where it's at?
08:37	Fossi	ok, was in seq-utils
09:06	LauJensen	~paste
09:06	clojurebot	lisppaste8, url
09:06	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
09:08	lisppaste8	Lau pasted "Character cast? http-client" at http://paste.lisp.org/display/85731
09:08	LauJensen	Does anyone know whats going on here?
09:09	Chouser	perhaps you want into-array ?
09:10	LauJensen	"Dont know how to create iseq from FilePart"
09:10	Chouser	(into-array [(FilePart. ...)])
09:10	saml	man i thought i modified JLine so that tab completion works on windows.. but that only worked at the beginning of a line
09:11	LauJensen	Chouser, certainly you mean (defmacro >array [arg] `(into-array [~arg])) ?
09:11	LauJensen	Anyway, it did the trick, thanks alot :)
09:14	LauJensen	Wow - I just did a POST upload of a picture. Impressive :)
09:15	Chouser	nice.
09:18	LauJensen	Yea, thats really the goodness of running my website via compojure. Just added a POST /backdoor/ route handler, and there was no need to installed an ftp server or any such thing, which would have weakened the overall security of the server..
09:20	Chousuke	I suppose you have some access checks in place for that backdoor? :P
09:21	LauJensen	No, people can upload whatever they want. Nothing will be executable or exceed a certain size
09:23	LauJensen	Chousuke: When I want to msg either you or Chouser, I have to write 5 letters before I can tab-complete. This is not satisfactory so I'll have to ask you do change your nick to Sukechou instead.
09:23	Chousuke	Not going to happen :)
09:24	LauJensen	With all diligence, search my last statement for a "?" - It was not a question boy
09:24	LauJensen	(I'm kidding dont kill me)
09:24	Chousuke	I tabcomplete most people's names with a single character anyway
09:25	Chousuke	Irssi's tabcompletion is context aware so most of the time it gets the right name.
09:25	LauJensen	Cool
09:25	LauJensen	I'm on Pidgin though
09:25	Fossi	Chousuke: so it knows that i want to talk to you?
09:26	Chousuke	Fossi: It prefers people who were last active.
09:26	Chouser	I've considered using a nick that's visually distinct to reduce confusion (even though I've had my name longe ;-)
09:26	Fossi	well, that would surely help me in this case ;)
09:26	Fossi	i meant the completion
09:26	Chouser	something like Ch_ouser. Or cccchouser. TheChouser
09:27	lrenn	LauJensen: Does that mean you solved your URLDecode problem?
09:27	LauJensen	lrenn: It means I've found one way of getting around it. Not optimal, since I dug into org.apache.commons, forsaking stuarts http-client
09:28	Chousuke	Chouser: You could always flip it around and make it ChrisH
09:31	LauJensen	Chouser: Then you wouldn't be mistaken for being Chinese
09:31	Chouser	Does chouser sound chinese?
09:32	LauJensen	Yes sir
09:38	Chouser	Chousuke: Or you could use Jarkko :-)
09:39	Chouser	no other ja* in here
09:41	LauJensen	Also a good point Mr. Chen
09:45	Chousuke	Chouser: Yeah, I could, but I doubt I will. :P
09:45	Fossi	,(str (/ 100 3))
09:45	clojurebot	"100/3"
09:46	Fossi	i'd really start thinking if my name was chous' uke
09:46	Chousuke	:P
09:46	Fossi	except of course if you like a little homoerotic touch :D
09:47	Chousuke	that's just forcing it.
09:47	Fossi	i hope not :D
09:48	Fossi	(it won't get any better from here ;)
09:48	Chousuke	besides, you're not allowed to break the name between s and u. that's impossible in Japanese orthography :P
10:40	stuartsierra	Tried to improve performance on base64 in Clojure. http://bit.ly/3ZArh7
10:40	stuartsierra	Still 10-20 times slower than Commons Codec, I think limited by boxed bit-ops.
10:42	cemerick	unless one is targeting Android, etc., why not just use the com.sun stuff?
10:42	clojurebot	http://clojure.org/rationale
10:42	cemerick	clojurebot: don't talk to me about full-stack impls, dammit! :-P
10:42	clojurebot	Huh?
10:44	stuartsierra	No reason. I'll probably continue using Commons. I just wanted to see if I could do it.
10:44	Chousuke	stuartsierra: hmm, did you try if escape analysis has any effect on it?
10:44	stuartsierra	nno
10:45	cemerick	Don't mind me, I get twitchy when I see pure-clojure reimpls of existing java libs.
10:45	stuartsierra	But I offer the code up as an optimization challenge.
10:45	cark	stuart : the line variable could be forced to an int and you could use unchecked functions for it
10:45	Chousuke	hmm
10:45	stuartsierra	cark: tried it, difference was neglible
10:45	Chousuke	I wonder if make-array returns a type-hinted array.
10:46	cark	i guess you checked everything with warn-on-reflection true ?
10:46	stuartsierra	I don't think so. But I already checked that there are no reflective calls.
10:46	cark	ok
10:46	Chousuke	warn-on-reflection doesn't warn about array reflection
10:46	stuartsierra	pre-boxing the bytes as Integers yielded about 10% improvement.
10:47	Chousuke	~def bit-and
10:47	Chousuke	hmm. looks like it does inlining at least.
10:48	cark	ah these re inlined
10:48	Chousuke	Is there really no primitive implementation for them? :/
10:49	stuartsierra	Apparently not. Look at the BitOps classes in clojure/lang/Numbers.java
10:49	cark	well this goes to prove that it's good we have java to fall back to for low level stuff
10:50	cark	but it worries me for clojure-in-clojure ...
10:51	cark	will we loose lot of performances on data structures ?
10:51	Chousuke	cark: there's new-new now. you can actually implement interfaces with methods that take and return primitives now.
10:52	cark	what version is it scheduled for
10:52	cark	?
10:52	Chousuke	1.1 most likely :P
10:52	cark	cool =)
10:53	Chousuke	http://clj-me.blogspot.com/2009/08/clojure-as-fast-as-java.html
10:54	cemerick	ugh, that title makes me cringe now
10:55	stuartsierra	I can imagine a really clever compiler that provides a dynamically-typed implementation of bit-ops as a default, but generates primitive methods as needed based on type tags.
10:56	cark	i don't expect the clojure compiler to ever become very smart... it's ok as long as we have the java alternative
10:58	Chousuke	I think we have all the tools now to start rewriting a compiler in Clojure but no-one has started anything yet :/
10:58	cark	maybe with compiler macros we could already do los of optimizations
10:58	stuartsierra	Perhaps the good is the enemy of the perfect.
10:59	Chousuke	I unfortunately know nothing about designing compilers so I wouldn't know where to start ;/
11:00	Chousuke	Looking at the java compiler for inspiration is probably not a good idea.
11:01	cemerick	it seems like stuff like this definitely belongs in the host platform. Even if the clojure compiler were to get super-smart about these sorts of things, it seems like such an impl would depend on Java at the moment, making those optimizations pointless when js or objc or llvm, et al. is the host platform.
11:02	Chousuke	When I first started writing my clojure-reader I started with a PushbackReader and looked at the java implementation to see how it did things; I didn't get very far.
11:03	Chousuke	Then I restarted and ignored the java reader and started writing one that just takes a seq of strings as its input. Now it's progressing rather well
11:04	cemerick	almost certainly not as fast, but I'll bet it'll be a dream to maintain (by comparison)
11:04	Chousuke	Though I'll probably have to change how the input is fed to it. Because it requires a line-seq, you can't just read "(foo)" from a "(foo)(bar)\n" stream without reading the (bar) from the stream as well
11:05	Chousuke	but it works character-by-character so that shouldn't be impossible.
11:05	Chousuke	and yeah, performance is also a secondary concern
11:06	danlarkin	Chousuke: feature request: """triple quoted strings""" :)
11:06	cemerick	that's part of why I'm definitely going to produce a binary, serialization-based print-dup alternative -- reading will only get slower over time
11:06	stuartsierra	I used a PushbackReader in my JSON lib, worked fine, but the result was still imperative-looking.
11:06	Chousuke	danlarkin: I'll implement feature parity first.
11:06	Neronus	re smart compiler: The clojure compiler doesn't need to be that smart. javac isn't really smart either
11:06	Chousuke	and even if the reader turns out not quite good enough, I hope my helper functions will be useful at least :P
11:07	cemerick	danlarkin: to handle the 80% userland reader macro use case?
11:07	Chousuke	I already have a syntax-quote macro
11:07	danlarkin	cemerick: hm?
11:07	Chousuke	which I haven't tested thoroughly, but it appears to work :P
11:08	cemerick	danlarkin: I thought that's why you were suggesting triple-quoted strings
11:08	danlarkin	cemerick: oh, I want them so one doesn't have to escape inside docstrings
11:08	cemerick	ah
11:09	cemerick	heh, that'd make things easier for tools to reformat code + docs
11:10	Chousuke	If I could use something like fnparse I bet writing the reader would be ridiculously easy.
11:10	cemerick	there was a discussion on the group about using triple-quoted strings as a way to cover some large chunk of the use-cases for reader macros
11:10	danlarkin	and writing docstrings a lot more sane...
11:11	danlarkin	I must've missed that discussion
11:11	danlarkin	sounds interesting
11:12	cemerick	it was earlier this week, I think
11:20	LauJensen	~paste
11:20	clojurebot	lisppaste8, url
11:20	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
11:20	lisppaste8	Lau pasted "POSTing a file" at http://paste.lisp.org/display/85738
12:34	Chousuke	hm.
12:35	Chousuke	I'm again getting the eldoc lag with clojure-mode :(
12:35	Chousuke	earlier, it did seem like it honoured the setting
12:35	Chousuke	but now it doesn't, again.
13:32	LauJensen	Sukechou: Sounds awful
13:32	LauJensen	Whats eldoc doing for you ?
13:52	Chousuke	LauJensen: :P
13:52	Chousuke	LauJensen: I don't know what's causing it.
13:52	LauJensen	Sukechou: What it meant was: What do you gain from eldoc, I never used it?
13:53	Chousuke	it shows the arglists in the minibuffer.
13:53	Chousuke	LauJensen: but for some reason, clojure-mode ignores the eldoc delay altogether and that causes lag in display rendering.
13:53	Chousuke	maybe I need to git bisect my config...
13:54	Chousuke	though it might just be some incompatibility with clojure-mode and the version of clojure I'm using.
13:54	Chousuke	and/or swank
13:55	Chousuke	I'm somewhat behind master in my clojure-reader branch. I haven't done a merge since I started coding it.
13:56	Chousuke	and I won't, until I'm mostly done with it. :P
13:56	tomoj	are we supposed to have tab-completion in source buffers, or just in the slime repl?
13:56	LauJensen	How close are you to completeting it ?
13:56	LauJensen	tomoj: In source buffers you can also have it by binding tab to dabbrev-expand as I recall
13:57	tomoj	LauJensen: nice, thanks
13:57	Chousuke	LauJensen: Well, it's almost at feature-parity I think.
13:57	Chousuke	missing unicode escapes, #! and #_ ... and maybe some other stuff I've forgotten.
13:58	LauJensen	feature-parity = feature-complete?
13:58	Chousuke	I guess.
13:59	Chousuke	But after I'm done with the basic functionality there's still a fair amount of work before it can replace the java reader.
14:00	Chousuke	if you want to play with it, you can find it on my github, entirely undocumented!
14:00	LauJensen	I cant help wonder why its such a big challenge to write a reader where you already have the java code ?
14:00	Chousuke	Well, I'm not looking at the java code at all :P
14:00	Chousuke	But it hasn't been much of a challenge so far, really. :)
14:01	Chousuke	I've just been slow with it.
14:01	Chousuke	implementing a feature or two at a time whenever I feel like it. :P
14:01	LauJensen	Ah ok
14:01	LauJensen	Spoken like a true freetard :)
14:01	Chousuke	Well, I'm in no hurry.
14:02	Chousuke	I suppose I should add my rh-from-string function to the source file :P
14:04	wtetzner	hey guys, i wrote an ant build script for one of my projects, and when compiling i get this error: [java] Exception in thread "main" java.io.FileNotFoundException: Could not locate clojure/test__init.class or clojure/test.clj on classpath: (read.clj:33)
14:04	wtetzner	does anyone know what i'm missing from the classpath?
14:04	Chousuke	the consume function takes a "reader-handle" which is a fancy way of saying "a pair containing lines a seq of strings and an offset to the current line"
14:04	wtetzner	i included clojure.jar and clojure-contrib.jar
14:04	Chousuke	as*
14:05	Chousuke	wtetzner: which version of clojure?
14:05	wtetzner	1.0
14:05	Chousuke	1.0 doesn't have clojure.test
14:05	wtetzner	hmm
14:05	Chousuke	you need a recent version from from git
14:05	wtetzner	ok
14:06	LauJensen	Its also worth noting that tests are primarily for noobs
14:07	wtetzner	Chousuke: so if 1.0 doesn't have clojure.test, why would it be looking for it when compiling a class?
14:09	hiredman	wtetzner: are you using the 1.0 compat branch of contrib?
14:10	wtetzner	hiredman: i don't know
14:10	wtetzner	that might be the problem
14:10	wtetzner	how do i know if it's compatible?
14:12	wtetzner	hiredman: that was the problem
14:13	wtetzner	hiredman: i used the wrong version of clojure-contirb
14:13	wtetzner	thanks
14:16	LauJensen	Gents - I'm trying to file an image to disk via a bufferedimage. There's a static function called ImageIO/write which should handle this and it works when I output my image as png, but b0rks when I choose jpg. Any idea why ?
14:17	Chouser	I have a vague recollection of needing some kind of external plugin to write certain kinds of image file formats. I may be pretty off base though.
14:18	LauJensen	They docs say the same thing, but for everything but gif, jpg and png, which should be available on all platforms
14:18	LauJensen	"Their"
14:20	LauJensen	Also - When I call ImageIO/getSupportedFormats it says jpg, JPG and jpeg are supported
14:21	LauJensen	,(doseq [r (ImageIO/getWriterFormatNames)] (print r))
14:21	clojurebot	java.lang.Exception: No such namespace: ImageIO
14:22	LauJensen	,(doseq [r (javax.imageio.ImageIO/getWriterFormatNames)] (print r))
14:22	clojurebot	BMPbmpjpgJPGwbmpjpegpngPNGJPEGWBMPGIFgif
14:24	Chouser	what kind of b0rks do you get?
14:24	LauJensen	Ah, "JPG" works...
14:24	LauJensen	Exception in thread "AWT-EventQueue-0" javax.imageio.IIOException: Invalid argument to native writeImage
14:24	LauJensen	at com.sun.imageio.plugins.jpeg.JPEGImageWriter.writeImage(Native Method)
14:24	LauJensen	at com.sun.imageio.plugins.jpeg.JPEGImageWriter.writeOnThread(JPEGImageWriter.java:1055)
14:24	LauJensen	at com.sun.imageio.plugins.jpeg.JPEGImageWriter.write(JPEGImageWriter.java:357)
14:24	LauJensen	(oops, sorry, I know that was 4 lines)
14:26	LauJensen	JPEG didnt work either
14:26	LauJensen	jpg in its entirety is b0rked
14:28	tomoj	LauJensen: which java?
14:28	l0st3d1	Hi - newbie question - If I have a list like '(1 2 3 4 5) how do I turn that into a list of lists with every combination missing, i.e. '(1 2 3 4 5), '(nil 2 3 4 5), '(1 nil 3 4 5). '(nil nil 3 4 5), etc ?
14:28	LauJensen	Gif and Png works, Bmp outputs faulty file, jpg doesnt output anything
14:28	LauJensen	tomoj: 1.6
14:28	tomoj	sun?
14:29	LauJensen	Si
14:29	tomoj	dunno then
14:29	cemerick	LauJensen: you're doing something wrong :-)
14:29	LauJensen	cemerick: thanks for chiming in, we'll talk tomorrow right? :)
14:29	cemerick	?
14:29	Chouser	l0st3d1: how long do you expect that list to get?
14:30	LauJensen	Hmm, whats openjdk doing on this system ?
14:30	l0st3d1	10 - 15 items
14:30	tomoj	LauJensen: that could be the problem
14:30	LauJensen	tomoj: Of course its the problem. its developed by freetards and lusers (quote linuxhater)... :)
14:35	LauJensen	apt-get purge openjdk* , and tada!! :)
14:35	LauJensen	Thanks for staying sharp tomoj
14:36	l0st3d1	chouser: 10 - 15 items, so not too long. I started with (let [l '(1 2 3 4 5)] (for [i l] (map #(if (not (= % i)) % nil) l))), but I'm not sure how to proceed
14:36	Chouser	l0st3d1: a tidy recursive solution seems likely.
14:37	tomoj	looks like 32 items to me
14:38	LauJensen	Ok, interesting. The image is now outputted without errors, the resolution is correct, but its entirely black, all details are lost. And only when output in jpg
14:40	Chouser	(defn nils [c] (let [[c1 & cs] c] (if cs (concat (map #(cons c1 %) (nils cs)) (map #(cons nil %) (nils cs))) [[c1] [nil]])))
14:41	Chouser	,(letfn [(nils [c] (let [[c1 & cs] c] (if cs (concat (map #(cons c1 %) (nils cs)) (map #(cons nil %) (nils cs))) [[c1] [nil]])))] (nils '(1 2 3)))
14:41	clojurebot	((1 2 3) (1 2 nil) (1 nil 3) (1 nil nil) (nil 2 3) (nil 2 nil) (nil nil 3) (nil nil nil))
14:42	tomoj	I guess before you blow the stack you'll have far too many possibilities anyway?
14:42	Chouser	that'll blow the stack for longer input lists
14:42	LauJensen	Chouser, isnt this where you trampoline it instead?
14:43	Chouser	that'd be one solution for longer lists. I'm sure there are others.
14:43	l0st3d1	Chouser: excellent ... thanks ... I was messing with embedded fors ... longer lists and performance aren't a problem for me right now ... many thanks
14:44	Chouser	I think using 'for' instead of recursion would only work if you new the length of the list at compile time.
14:44	Chouser	you'd need one 'for' clause per list item
14:45	Chouser	you could use 'for' instead of the 'map' in my solution of course, and still recurse.
14:45	l0st3d1	I'm slowly reading your solution and trying to inderstand ;)
14:46	l0st3d1	I was trying to build a partial list in an outer for and mapping all the things in the outer list to nil in an inner list ...
14:46	l0st3d1	I'm sure it wouldn't have worked ;)
14:58	LauJensen	Ok - The situation is this. Using Sun-java6 I can save an imageicon=>bufferedimage=>file. Perfect. Except to save it correctly you need to know the type of the image, for instance TYPE_INT_RGB. This differes from image to image. Anybody know an easy way to determine which type is correct?
15:00	wtetzner	hey guys, another question: i'm signing some jar files to be run as an applet, and i'm getting the error: Exception in thread "main" java.lang.SecurityException: class "clojure.proxy.java.lang.Object$ActionListener"'s signer information does not match signer information of other classes in the same package
15:00	wtetzner	i think it's because the actionlistener class ends up in the same jar file as the applet jar
15:00	wtetzner	but clojure is in its own jar file
15:01	wtetzner	is there a solution to this?
15:01	Chouser	I've always put all classes into a single .jar file for applets
15:02	wtetzner	so you unzip clojure.jar etc. and put the contents into the applet jar?
15:02	Chouser	yeah
15:02	wtetzner	ok
15:02	Chouser	dunno if that's right or recommended or anything, but I never figured out how to specify more than one .jar for an applet, so this is what I've been doing.
15:04	wtetzner	in the applet tag, you can use the archive attribute: archive="applet.jar,clojure.jar,clojure-contrib.jar"
15:05	wtetzner	but if you sign each one separately, even using the same certificate, it doesn't like it
15:05	wtetzner	if two things from the same package are in different jars
15:06	wtetzner	are there any licensing issues of me moving the ActionListener stuff to the clojure.jar file?
15:08	Chouser	I think you can combine the .class files in whatever jars you want. Distributing modified class files is where you start running into restrictions. I think.
15:08	wtetzner	ok
15:08	wtetzner	thanks
15:11	LauJensen	Ok - The situation is this. Using Sun-java6 I can save an imageicon=>bufferedimage=>file. Perfect. Except to save it correctly you need to know the type of the image, for instance TYPE_INT_RGB. This differes from image to image. Anybody know an easy way to determine which type is correct?
15:11	LauJensen	Followup: I've now tried forcing all image types indivually and none of them emits a correct image - whats up !?
15:12	Chouser	LauJensen: maybe #java can help you?
15:12	LauJensen	Last resort
15:13	hiredman	are you sure imageicon is what you want?
15:14	LauJensen	Ok, update: passing the getScaledInstance image through ImageIcon through .getImage did the trick
15:14	LauJensen	All is well in la la land
15:15	hiredman	ImageIO can give you a buffered image from a url
15:16	LauJensen	Trouble is I wont always have an Url, sometimes I'll just have some scaling factors and an image
15:16	LauJensen	But its working now
15:17	LauJensen	True to Clojure's slogan "I get by with a little from my friends"
15:33	Chouser	I guess it hinges on the phrase "derivitive work". I would assume changing Clojure's sourse results in a derivitive work, but I would think combining it in a jar with other stuff does not?
15:35	tomoj	"contributions do not include additions to the program which... are seperate modules of software distributed in conjuction with thi program under their own license agreement"
15:35	Chouser	ah, nice.
15:35	rsynnott	that's a nice clarification
15:35	rsynnott	far too many people either don't clarify or clarify the other way ;)
15:36	rsynnott	(the authors of clisp, for instance, claim that any piece of software written in clisp and accessing the foreign function interface _falls under GPL for redistribution purposes_)
15:36	Chouser	that then shifts to what makes up a "module". I suppose, one might try to claim that's what a .jar is.
15:41	wtetzner	why are classes created by proxy in the clojure namespace vs the namespace proxy was called in?
15:45	tomoj	second clause in that list was that contributions do not include additions which are not derivative works :)
15:45	Chouser	this has come up before. As it is, multiple namespaces can share the same proxy class if it would be identidal
15:45	Chouser	also they're put in a package that's not used for anything else, which reduces the changes of collision.
15:46	Chouser	wtetzner: all that said, it might be better to put them elsewhere for easier packaging.
15:54	weissj	I'd like to make a function that if I pass it '("user" "passwd") it will return a lazy seq of ("user1" "pass1"), ("user2" "pass2") ...
15:55	weissj	i can't quite figure out where to put the call to inc :)
15:55	weissj	sorry s/passwd/pass
15:56	wtetzner	Chouser: yeah, for now i'm just putting everything in one jar
15:56	wtetzner	Chouser: but it would be nice to not have to upload all of the clojure stuff every time i re-upload the applet
15:56	Chouser	yeah
15:57	Chouser	wtetzner: do you really have to sign the applet?
15:59	wtetzner	Chouser: i got security exceptions from dynamic class loading when the applet wasn't signed
15:59	Chouser	if you're careful to remove all reflection and AOT compile it, those go away.
16:00	Chouser	,(letfn [(crack [c] (cons c (map (fn [n] (map #(str % n) c)) (iterate inc 1))))] (take 3 (crack '("user" "pass"))))
16:00	clojurebot	(("user" "pass") ("user1" "pass1") ("user2" "pass2"))
16:00	wtetzner	Chouser: how can i tell if i've removed all reflection?
16:00	weissj	Chouser: thanks
16:00	Chouser	(set warn-on-reflection true) before you even do (ns ...) at the top of your file.
16:00	wtetzner	Chouser: oh, ok
16:01	Chouser	then you'll get warnings at compile time for code that would cause security exceptions at runtime
16:01	wtetzner	Chouser: so to remove reflection, what do i need to do? just add in type hints?
16:03	Chouser	wtetzner: generally, yeah.
16:03	Chouser	hm, last I checked 'ns' itself generated some reflection. I have a patch for that, but haven't mentioned to anyone yet.
16:04	Chouser	http://tinyurl.com/nqqubv -- clojure-type-hints.diff
16:05	Chouser	dunno if that's still needed or not
16:08	Chouser	ah, it is. Or use the patch here: http://www.assembla.com/spaces/clojure/tickets/171
16:09	wtetzner	Chouser: also, i wanted to be able to use the java web start, and i think that requires that the files are signed
16:09	wtetzner	Chouser: i want the ability to drag the applet from the browser, and create a link on the desktop
16:09	Chouser	ah, that's why I asked in the first place.
16:10	Chouser	If you have some other reason to sign it, it's probably not worth chasing down all the runtime reflection (except possibly for performance).
16:10	wtetzner	Chouser: yeah, it seems like a lot of work to add all those type hints
16:10	Chouser	yep.
16:10	wtetzner	and then the code doesn't look as pretty
16:21	LauJensen	Anybody here know how to integrate a .clj script into nautilus' right-click menu ?
16:24	angerman	how would I translate something like Foo.class (java) to clojure?
16:24	hiredman	Foo
16:27	Chouser	no official way to get to a map's .keySet() method?
16:28	wtetzner	what does .keySet() do?
16:28	Chouser	it seems sad to do an O(n) (set (keys my-map)) when (.keySet my-map) is there already.
16:29	kotarak	Chouser: well keys could return the keySet, no? (Dunno whether it does...)
16:29	wtetzner	keys returns a sequence of keys
16:30	kotarak	Then it could be modified to return the keySet...
16:30	wtetzner	or just add a key-set function to clojure.core
16:30	kotarak	(which might not help much, if the set has to be constructed internally also....)
16:31	kotarak	I think (.keySet some-clojure-map) already works.
16:31	wtetzner	yeah
16:31	wtetzner	but it's not as pretty as (key-set some-clojure-map)
16:31	Chouser	not as pretty and more likely to change out from under me.
16:31	wtetzner	oh yeah, that too
16:32	kotarak	Chouser: then work on rhickey to get keys returns the set. :) Turning it back into a seq is possible anyway...
16:33	Chouser	well, that's why I'm asking.
16:36	rhickey	as long as a map is a Map then keySet will work
16:36	rhickey	e.g. low risk
16:36	Chouser	ok
16:37	Chouser	if 'keys' only promised a collection instead of a seq, it could call .keySet itself.
16:52	wtetzner	i don't know if you guys have seen this already, but this is a set of "look and feel"'s for swing
16:52	wtetzner	https://substance.dev.java.net/see.html
16:52	wtetzner	it makes swing look really good
16:53	gko	hello.
16:55	cemerick	wtetzner: yeah, substance is awesome. I'm hoping NetBeans becomes compatible with it in v7.
16:56	wtetzner	i think one of the reasons people don't like java applications is that the default gui is so ugly
16:57	gko	I have code like this: ... (let [x (produce-a-list) b (map #(use-list %) x)]) ...
16:57	gko	after (produce-a-list), x has for example 10 elements, but when using map, the use-list function is called only twice...
16:58	Chouser	gko: map is lazy
16:58	Chouser	gko: it will call use-list only as many times as needed, based on whatever is using b
16:59	gko	Chouser: so doall ?
16:59	Chouser	if use-list has side-effects, and you want those to happen for every item in x, I'd recommend doseq
16:59	gko	Chouser: but in the let, the list is used...
16:59	Chouser	but doall and/or runall might do as well.
17:00	Chouser	gko: oh, it has side effects and the return values are used?
17:00	gko	yes
17:01	Chouser	it might be worth trying to split that up a bit -- keep your side-effect stuff as separate as possible from the seq/computational stuff.
17:01	Chouser	but failing that, doall or vec wrapped around map will force it and let you get at the values.
17:03	gko	not working with doall...
17:03	gko	I have code like this: ... (let [x (produce-a-list) b (map #(use-list %) (doall x))]) ...
17:03	Chouser	(doall (map use-list x))
17:03	kotarak	(doall (map ...))
17:03	wtetzner	gko: call doall over the map
17:04	gko	Oh... It works now... Thanks!
17:05	gko	Have seriously to read that chapter 5 ..
17:57	sh10151	I really dislike Groovy. :(
17:57	Chouser	hm, what's groovy's weak spot? macroless? How's its performance?
17:58	Chouser	mutable
17:58	sh10151	They have a way to get at the abstract syntax tree
17:58	sh10151	not sure if anyone would care either way, though
17:59	sh10151	Unfortunately I think the main reason it's gotten traction is it is designed to look enough like Java to fool the unwary.
17:59	Chouser	yeah
17:59	sh10151	never mind that declaring a variable a certain type and then assign to it does an autocast, even when an autocast is nonsensical
18:00	sh10151	I mean, honestly if it were familiarity they were after, JavaScript Rhino should have been top choice -- but no one hypes it.
18:00	hiredman	yeggie did
18:00	sh10151	Groovy seems to have a big hype machine on the enterprisey blogroll
18:00	sh10151	yeah and look what happened to him!
18:00	sh10151	like that! poof he's gone!
18:00	Chouser	what did happen to him?
18:00	sh10151	;)
18:00	hiredman	good point
18:01	sh10151	probably got pulled into Google's V8 and now can't talk about it any more...
18:01	sh10151	just my theory
18:01	hiredman	ooo
18:01	sh10151	You like JavaScript eh, well JavaScript This!
18:03	sh10151	anyway, not sure what to do about it. I'm giving a presentation on Clojure at work next week but who knows how it will be received. :)
18:03	hiredman	hard to say, I have difficulty imagining anyone not jumping on clojure, but I guess I am brainwashed
18:04	Chouser	.keySet returns a set that is not a IFn
18:05	hiredman	how unfortunate
18:05	hiredman	~ticket #69
18:05	clojurebot	{:url http://tinyurl.com/ntknnt, :summary "GC Issue 66: Add \"keyset\" to Clojure; make .keySet for APersistentMap return IPersistentSet", :status :test, :priority :low, :created-on "2009-06-17T19:55:38+00:00"}
18:06	Chouser	huh!
18:07	sh10151	well
18:07	sh10151	early feedback is people are prejudiced against Lisp ;)
18:08	Chouser	I'm shocked. shocked.
18:08	hiredman	sh10151: shows what they know
18:10	sh10151	well, again if they were like "JavaScript works fine for us" that'd be one thing
18:10	sh10151	but clojure is sensitive to where you stick newlines, and in a semantic way not a syntactic way
18:11	sh10151	i.e. if you put a newline in one place, it behaves one way, and if you put a newline in another, it behaves differently
18:11	Chouser	that's groovy?
18:11	sh10151	sorry
18:11	sh10151	s/clojure/groovy/ of course :)
18:11	Chouser	javascript can occasionally have issues with that too
18:11	hiredman	sh10151: do you have anything on groovy clojure integration?
18:12	sh10151	http://groovy.codehaus.org/Things+you+can+do+but+better+leave+undone
18:12	sh10151	hehe no :)
18:12	sh10151	Chouser: yes but not as frequently because JavaScript doesn't use a bare {} as its anonymous function syntax
18:12	hiredman	if you can get them to use clojure datastructures in groovy you are most of the way there
18:12	Chouser	sh10151: ah.
18:13	syamajala	i need a crash course in java
18:13	syamajala	is there a good book?
18:13	sh10151	hiredman: hey, that's a good point
18:13	sh10151	hiredman: I might give that a shot
18:13	hiredman	http://groovy.codehaus.org/JSR-223+access+to+other+JVM+languages
18:14	syamajala	i have experience with lisp/clos, ruby, and c, as well as a tiny bit of objc, but have never used java
18:14	syamajala	i've also read a bunch programming clojure
18:15	hiredman	there are video lectures on java from a few schools out there
18:15	sh10151	syamajala: Maybe the Core Java book?
18:15	sh10151	syamajala: Whatever you do, make sure it's recent
18:15	sh10151	syamajala: covering Java 5 at least
18:16	sh10151	I thought "The Java Programming Language" to be reasonable.
18:16	sh10151	not quite as nice as "The C Programming Language" but that's down to all the libraries they cover.
18:17	syamajala	ok, i'm really just looking for something lite that can quickly get me up to speed on java's version of oop
18:17	hiredman	http://webcast.berkeley.edu/course_details_new.php?seriesid=2008-D-26332&semesterid=2008-D is java
18:19	sh10151	"Effective Java" is light
18:19	sh10151	but you'd have to pick up a lot by reading between the lines as far as basic syntax goes
18:20	sh10151	I just have two Java books on my bookshelf: "The Java Programming Language" and "Effective Java."
18:20	sh10151	the rest is pretty much in the javadocs online
18:21	hiredman	being able to read javadocs is best
18:21	hiredman	actually knowing java is kind of secondary
18:22	syamajala	sh10151: i don't think syntax will matter much because of clojure
18:23	syamajala	it would just better if i actually knew what things like a proxy are
18:23	sh10151	in clojure or in java?
18:23	syamajala	java
18:23	hiredman	,(class (proxy [Object] []))
18:23	clojurebot	java.lang.IllegalStateException: Var null/null is unbound.
18:23	hiredman	ouch
18:23	sh10151	in clojure it's just a short way to write new Interface() { public method1() {}} etc
18:23	sh10151	at least afaict
18:24	hiredman	,(class (proxy [clojure.lang.IDeref] [] (deref [] 1)))
18:24	clojurebot	java.lang.IllegalStateException: Var null/null is unbound.
18:24	hiredman	odd
18:24	Chousuke	hmm.
18:24	Chousuke	:p
18:24	syamajala	sh10151: see, i have no idea what an interface is though
18:24	Chousuke	syamajala: just a bunch of methods :)
18:24	syamajala	kinda like generic functions?
18:24	hiredman	no
18:24	sh10151	syamajala: In Java an interface is a data type
18:24	Chousuke	an interface is a bunch of methods for a class to implement.
18:24	hiredman	an interface is a collection of method signatures
18:25	syamajala	ok
18:25	syamajala	yeah this is the type of stuff i need to learn...
18:25	hiredman	a class implements an interface by provoding bodies
18:25	sh10151	maybe you should go l33t and read "A Little Java, A Few Patterns"
18:25	sh10151	it's very light
18:26	sh10151	not exactly high on the "best practices for enterpisey java" chart though
18:26	hiredman	http://math.hws.edu/javanotes/
18:26	syamajala	;-D it looks like the little schemer!
18:28	sh10151	syamajala: exactly so
18:28	sh10151	syamajala: actually it's pretty good
18:28	sh10151	syamajala: It might have been the first Java book I read
18:28	syamajala	is it the same question answer type thing?
18:28	sh10151	syamajala: yes
18:28	sh10151	syamajala: and don't read it on an empty stomach
18:28	sh10151	syamajala: it's all about pizza
18:28	syamajala	heh
18:29	sh10151	definitely covers interfaces though
18:29	sh10151	and how they work in patterns
18:30	syamajala	my neighbor let me borrow the little schemer when i was in high school, it helped with understanding recursion
18:31	sh10151	i will bbl
18:31	sh10151	toddler on rampage
18:32	syamajala	maybe i should get a few other books while i'm at it
18:32	hiredman	there is a clojure bookshelf
18:32	hiredman	~books
18:32	clojurebot	Titim gan éirí ort.
18:32	hiredman	~bookshelf
18:32	clojurebot	It's greek to me.
18:32	hiredman	bah
18:32	syamajala	i mean other books
18:33	syamajala	i've always wanted to learn haskell and erlang
18:33	hiredman	syamajala: books on those languages are on the list
18:33	hiredman	~bookshelf is http://www.amazon.com/Clojure-Bookshelf/lm/R3LG3ZBZS4GCTH
18:33	clojurebot	You don't have to tell me twice.
18:34	syamajala	prolog!
18:37	hiredman	total for the list is only $1,670
18:38	syamajala	i have some very big lists
18:38	syamajala	47 cs books and 46 math books
19:06	lowlycoder	does clojure have any good constructs for persistence/hibernation?
19:06	cemerick	for those who frequent databases: are there any good clojure-y strategies for coordinating database operations and in-memory state?
19:12	cemerick	hrm, I wonder if I'm overusing (-> foo .bar .baz (.blah arg))
19:15	Chouser	cemerick: is that even possible?
19:15	cemerick	well, my code is becoming littered with them :-P
19:16	cemerick	there's borderline case of (.method (SomeClass/staticMethod) arg) vs. (-> (SomeClass/staticMethod) (.method arg))
19:16	cemerick	I suppose the latter is clearly preferable, but I start worrying when I use something too much :-)
19:18	lowlycoder	how can i, on exception, get a repl in the stack frame, rather than ust
19:18	lowlycoder	just a printout of the stack frame?
19:22	cemerick	lowlycoder: get a repl in the stack frame?
19:22	lowlycoder	yes
19:22	lowlycoder	and to be able to move up & down frames
19:22	cemerick	ah
19:22	cemerick	can't with the current impl
19:22	lowlycoder	so when it gives me an error of saying "x" is nil, and I see what I have let [{x :x} p] ... i can see what p is
19:23	lowlycoder	wtf? isn't "exception triggers recursive repl" standard to lisps?
19:23	cemerick	definitely possible in the JVM, but not in place
19:23	cemerick	lowlycoder: common lisps, yes
19:23	lowlycoder	scheme as well
19:23	lowlycoder	i'm disappointed, ... it's a common way I debug code :-(
19:23	cemerick	well, scheme is a broad world :-)
19:23	lowlycoder	how do you debug clojure code without recursive repl, println's all over the place?
19:24	Carkh	cemerick : really , possible in the jvm ?
19:24	Carkh	that would be so cool =)
19:24	cemerick	lowlycoder: no, current practice is to use a debugger. Enclojure is good in this respect.
19:24	Carkh	lowlycoder : i do print all over the place =)
19:25	cemerick	Carkh: yeah. Many Java IDE's are capable of "break on error" -- it's baked in to the JVM.
19:25	Carkh	debuggers are evil
19:25	cemerick	clojure doesn't hook into it, though.
19:25	cemerick	Carkh: it's all the same machinery, at least in the jvm / clr
19:25	Carkh	cemerick : i would love to break and add/modify definitions, common lisp style
19:26	cemerick	well, we're < 2 years in, CL's had ~25. Let's give it another year, and I'll bet you'll be able to do that. :-)
19:27	Carkh	hehe ok =-
19:27	rsynnott	common lisp's break isn't all that great in most implementations
19:27	clojurebot	Lisp isn't a language, it's a building material.
19:28	rsynnott	(and slime's support for it is generally very poor; it's one of the bits that isn't maintained well)
19:29	cemerick	agreed. I've seen some pretty hot stuff in lispworks, tho.
19:29	rsynnott	yep, lispworks has good debug facilities
19:29	rsynnott	the whole lispworks ide is terribly impressive
19:30	cemerick	I wonder if they could make a run at a clojure environment.
19:30	rsynnott	it's interesting that break-style debug facilities don't even seem to see much use, though
19:30	rsynnott	even where they work well
19:30	rsynnott	the slime one is basically undocumented
19:31	rsynnott	cemerick: I doubt you'd get a lispworks class slime dev environment without a major funded/commercial project
19:31	rsynnott	*clojure dev that is
19:31	cemerick	yeah, that's what I was saying.
19:31	rsynnott	MCL's was also quite nice
19:31	cemerick	e.g. a for-pay NetBeans plugin or whatever.
19:32	rsynnott	in my experience, even the best netbeans/eclipse plugins just aren't that food
19:32	rsynnott	*good
19:33	cemerick	no, mostly because they're unambitious junk with no market
19:33	cemerick	there's no market for dev tools in general
19:33	rsynnott	hasn't been for a while
19:33	cemerick	but depending on how the community goes, they could have a growing market of clojure devs willing to drop some real money on a top-notch environment
19:33	rsynnott	the good ones are mostly built t a loss to push other products
19:34	rsynnott	x-code, visual studio etc
19:34	cemerick	I can't imagine there's much upside in the CL tooling space.
19:34	rsynnott	hasn't really happened elsewhere
19:34	rsynnott	ruby doesn't even have a slime-class dev environment, for instance
20:14	cemerick	maybe rather than eliminating use, (use foo.bar.baz) should expand to (require [foo.bar.baz :as baz])
20:14	cemerick	I do the latter constantly
20:44	JAS415	is it wrong to want java to be much less verbose?
20:44	JAS415	i can touch type pretty well and i'm getting tired
20:56	tomoj	use is going away?
20:58	cemerick	there's been a lot of talk about unifying require and use
20:58	cemerick	and require's usage is definitely more idiomatic
21:06	tomoj	what's a good way to represent a DAG?
21:06	tomoj	I'm thinking a vertex can be a map with an :edges key pointing to a vector of other vertices, as long as I never try to print that out
21:07	lowlycoder	why does immutabilty allow correct implementations of hashCode() and equals() autoamtically?
21:08	Chouser	tomoj: why could a vertex not just be a vector of other vertices?
21:09	tomoj	Chouser: need other info on each vertex
21:09	tomoj	hmm.. actually I need other info on each edge too :(
21:10	tomoj	lowlycoder: not sure what you mean by "allow"
21:10	tomoj	you could easily make an incorrect hashCode on an immutable data structure
21:11	Chouser	if you have a hash map keyed on mutable objects, and one of those object mutates, you have a real problem.
21:12	tomoj	hashCode is always an int, though, no?
21:13	lowlycoder	tomoj: 'allow' = autoamtically generate
21:13	lowlycoder	also, why does clojure lack continuations
21:13	tomoj	then it certainly doesn't
21:14	tomoj	I could hashCode my immutable data structure by returning the current time in seconds
21:14	Chouser	lowlycoder: clojure uses Java calling conventions for performance, and since Java doesn't have continuations, neither does Clojure.
21:15	cemerick	few programming environments outside of compliant schemes and smalltalk have "real" continuations
21:15	lowlycoder	so each clojure call is a java stack frame?
21:15	cemerick	yup
21:22	lowlycoder	are java exceptions are resumable? if so, how do I resume clojure code taht's shown an exception at the repl?
21:22	cemerick	unless you're running with a debugger that's stopping on exceptions, no.
21:23	lowlycoder	do these things not bother any of you?
21:23	cemerick	my code doesn't produce exceptions :-D
21:23	tomoj	if clojure weren't java, no one would know about it
21:23	tomoj	I'm ok with these things in return for java
21:24	cemerick	I took a round trip from Java -> python -> CL -> scala -> clojure. The tradeoffs with the last hit my sweet spot.
21:25	cemerick	well, actually, it was assembly -> RB -> CL -> scheme -> Java -> python -> CL -> scala -> clojure, but whatever :-)
21:25	lowlycoder	well, i started by pushing electrons around
21:26	tomoj	what's RB?
21:26	Ash	Root Beer
21:26	cemerick	lowlycoder: man, how do you get by with programming languages then? ;-)
21:27	cemerick	tomoj: RealBasic. It's actually a pretty pleasant environment. I picked it up in high school, used it for screwing around and started doing contract work.
21:27	cemerick	Then college hit, and someone threw MCL at me.
21:27	cemerick	if they had given me scheme at that point, I probably would have been a lot happier, a lot sooner
21:40	Chouser	Everytime I think I'm starting to understand git, I don't.
21:42	Raynes	I don't understand Git. I just use it.
21:43	Chouser	the latest commit is "Merge branch 'lazychain'", 'git show' shows me nothing, 'git diff HEAD^' show the preceding commit's diff
21:43	Chouser	I can't find any branch called 'lazychain'.
21:43	Chouser	what the heck was checked in?
21:44	rhickey	Chouser: lazychain was the name of my local branch, I guess that's an automatic message on merge
21:44	rhickey	I do all of my changes on local branches, then merge into master and push
21:44	Chouser	the interleave commit was in there?
21:45	rhickey	right
21:45	Chouser	ah, ok.
21:45	rhickey	only that
21:45	rhickey	I didn't know when I started the branch what the problem was exactly
21:45	Chouser	sure
21:46	Chousuke	Chouser: you might want to use some graphical tool for looking at git history. plain git log can be really confusing.
21:47	Chousuke	you can do a merge and then all the new commits introduced to the branch are somewhere down the log.
21:47	Chousuke	because they could be somewhat older than the other commits.
21:50	cemerick	Chouser: gitx is fan-freaking-tastic
21:51	lowlycoder	why is meta data useful? why do I want to use it?
21:52	lowlycoder	clearly, its important since it's got it's own macro reader symbol, but why?
21:53	Chouser	cemerick: wrong platform, but thanks anyway. :-)
21:54	cemerick	Chouser: no kidding, I pegged you as a mac user
21:54	cemerick	I mean, isn't everyone? :-P
21:55	cemerick	lowlycoder: lots of data is orthogonal to your domain data model
21:55	rhickey	gitx ... shiny
21:55	Chousuke	heh.
21:55	Chousuke	yeah, it's definitely shinier than gitk
21:56	cemerick	rhickey: whoa, yeah, you should've had that from the start :-)
21:56	tomoj	lowlycoder: used (doc ...) yet?
21:56	rhickey	cemerick: doing ok with IntelliJ's git support
21:56	cemerick	yeah. Honestly, I'm so pro-gitx because NetBeans sucks pretty hard on the git front.
21:57	cemerick	(not that it's not a nice tool all on its own)
21:57	rhickey	IntelliJ rules for Java
21:57	rhickey	IMO
21:57	Chousuke	on a semi-related note, I wonder what happened to egg
21:57	lowlycoder	tomoj: that's meta data ?
21:57	Chousuke	it's no longer showing me branch names in history view.
21:57	cemerick	rhickey: are you using the intellij clojure plugin as well, or still emacs?
21:58	lowlycoder	tomoj: whoa, the doc-string in defn is meta data?
21:58	Chouser	well maybe gitx would help. gitk's view of the log is hardly less confusing
21:58	Chousuke	,^#'+
21:58	clojurebot	{:ns #<Namespace clojure.core>, :name +, :file "clojure/core.clj", :line 629, :arglists ([] [x] [x y] [x y & more]), :inline-arities #{2}, :inline #<core$fn__4091 clojure.core$fn__4091@1bc6ed3>, :doc "Returns the sum of nums. (+) returns 0."}
21:58	rhickey	cemerick: I do look at and debug Clojure code in IntelliJ, but edit in emacs still until I'm 100% confident in the indentation, right now it is not as sophisticated as emacs for Lisp indentation
21:59	Chousuke	lowlycoder: all that is standard metadata found on most functions.
21:59	cemerick	lowlycoder just got bitten by the clojure bug :-P
21:59	cemerick	I wouldn't be able to cope with using multiple development environments
21:59	rhickey	does gitx do side-by-side?
21:59	lowlycoder	rhickey: hey, when are we going to get repls on exceptions? :-)
21:59	cemerick	hrm, I don't think so
22:00	rhickey	lowlycoder: not soon
22:00	lowlycoder	rhickey: why? what can I do to change that?
22:01	rhickey	cemerick: I'm used to this: http://cloud.github.com/downloads/richhickey/sdb/Picture_1.png
22:03	rhickey	lowlycoder: If you know about the Java debug API you might have a chance, but Clojure doesn't have the same kind of runtime infrastructure as say a typical CL
22:04	cemerick	rhickey: Both eclipse and netbeans have break-on-exception capability -- seems like there's a library that could be leveraged somewhere...
22:04	rhickey	cemerick: I'm happy for any contributions in that area, no doubt there are some facilities, just saying it's not going to fall out of the existing Clojure runtime
22:05	rhickey	also there's a debugger/debuggee dichotomy
22:05	cemerick	that's true
22:05	lowlycoder	how do you do exploratory programming without recursive repls / ability to resume on exceptions?
22:06	lowlycoder	above dichotomy = in existing libraries, i.e. if we use it', it's not clojure repl debugging a clojure program?
22:06	cemerick	but for the simple case, getting a repl and restart options should be doable, unless the IDEs are going some serious black magic
22:08	cemerick	rhickey: opendiff is pretty good if you like the side-by-side
22:08	cemerick	it's a darn good merge tool, actually
22:08	rhickey	cemerick: as I said, IntelliJ is working for me
22:09	tomoj	anybody use magit?
22:09	cemerick	sorry, I get chatty late at night
22:11	rhickey	:)
22:14	rhickey	lowlycoder: I'm open to contributions, myself, I don't like debugging
22:15	rhickey	more flightcaster: http://www.infoq.com/articles/flightcaster-clojure-rails
22:17	cemerick	hrm, ::foo is :myns/foo in a dosync, but ns is always clojure.core in a dosync
22:17	rhickey	I wonder how InfoQ does its schedule? I did a talk on state and identity at QCon I wish would come out soon
22:18	rhickey	cemerick: you are reading ::foo in a dosync?
22:18	tomoj	,(dosync ns)
22:18	clojurebot	#<Namespace sandbox>
22:19	cemerick	rhickey: I was actually filtering some keywords based on their namespace, and none of them were matching the name of ns. Somehow ns is always clojure.core in this particular snippet.
22:19	cemerick	^ but yes, the above in a dosync
22:20	cemerick	...not that I can replicate this problem in a smaller example.
22:22	rhickey	wow, Andy Fingerhut's transcription of the Boston Lisp talk is an act of heroism - 3800 lines!
22:25	lowlycoder	maps/sets having stable orders -- does that mean garbage collection does not change their order?
22:32	rhickey	lowlycoder: they are immutable
22:33	lowlycoder	good point
22:33	lowlycoder	rhickey: how did you support yourself while developing clojure?
22:34	rhickey	lowlycoder: used up my savings
22:35	lowlycoder	how does this play with parts of life like ... family & friends?
22:53	lowlycoder	why is there lef and letfn ?
23:00	tomoj	letfn is a handy shortcut for letting fns
23:01	Chouser	more than that. letfn allows local mutually-referential fns
23:02	tomoj	ooh
23:02	tomoj	I read "all the names" but that didn't click
23:02	tomoj	pretty cool
23:04	Chouser	but it only does fn. 'let' is for other locals.
23:04	clojurebot	for is not used enough
23:07	lowlycoder	what'sthe cost of using a trampolie?
23:08	Chouser	I think the biggest drawback is you have to write the caller and each callee with the knowledge that trampoline is being used.
23:10	lowlycoder	chapter 6, concurrency; this is a great day
23:13	cemerick	lowlycoder: and to think I had pegged you as a skeptic ;-)
23:21	lowlycoder	can refs be built out of atoms?
23:23	Raynes	(atom x @y)?
23:23	Raynes	Er, vice versa.
23:23	Chouser	refs and atoms are two kinds of reference types -- each are used to point to a value
23:23	Chouser	you wouldn't generally store one in the other, if that's what you're asking.
23:24	Raynes	(def x (atom @(ref 10))), is what I was trying to say. :< I should sleep more.
23:25	Chouser	but that's just copying a value out of one and storing it in the other.
23:25	Chouser	on another level, mixing refs and atoms seems a bit risky, since to the ref/transaction world, changes to atoms would be a kind of side-effect.
23:26	Raynes	Chouser: You could interpret what he said that way. He needs to clarify.
23:26	lowlycoder	i will clarify
23:26	lowlycoder	if I gave you clojure without refs & stms; and only atoms
23:27	lowlycoder	can you build stms & refs on top of that single primitive?
23:27	lowlycoder	like how locks can be built on top of only "compare & swap"
23:32	lowlycoder	if a dosync transaction block fails, do the java calls inside of it get rolled back too? (i'm guessing not, since I can do stuff like send packets over the network / delete files) ... if not, how do i know which pieces of java code got executed?
23:36	cemerick	lowlycoder: nothing gets rolled back except for the state of whatever refs have been touched by the transaction
23:37	lowlycoder	cemerick: ahh, nice; thanks, this is _really_ clear :-)
23:37	lowlycoder	so basically, clojure stms only act in clojure land, and doesn't care at all about the rest of the world
23:37	cemerick	so, if you've got anything side-effecting in your transaction, you're going to get burned eventually
23:37	lowlycoder	so even if I called a clojure wrapper for file i/o or network, i lose
23:37	cemerick	yes
23:38	cemerick	that is, unless you're very clear about what the semantics of the call are.
23:38	cemerick	e.g. file reads will generally be OK
23:38	lowlycoder	bank transactions may be bad ideas though?
23:39	cemerick	bank transactions are a great thing to do, as long as you're not writing out the result within the transaction
23:40	cemerick	e.g. if you had the bank transaction history in a persistent data structure, in a ref, applying changes to it in a concurrent environment would always give you a consistent picture before and after each clojure transaction
23:40	drewr	Chouser: destructuring isn't working with the new doseq
23:41	drewr	e.g., (doseq [[k v] {:foo 1 :bar 2}] (prn [k v]))
23:42	lowlycoder	cemerick: got it; thanks
23:47	drewr	Chouser: I take that back
23:48	drewr	I was having classpath issues while updating
23:52	Chouser	drewr: whew. thanks.
23:55	drewr	sorry to scare you
23:55	drewr	the exception I was getting was strange though; not sure why it would have happened with either version of the code