#clojure – 2009-10-02

2009-10-02

00:02	arbscht	hm, rfirst and rrest were replaced with nfirst and nnext during the lazy merge
00:08	adityo	good morning folks
00:08	arbscht	hi
02:34	konr	Is there a particular http client I should use?
02:35	arbscht	what are your requirements?
02:36	konr	hmmm... support for cookies... nothing much more complicated than that
02:41	arbscht	you could probably build on c.c.http-agent. if you want automatic cookie management maybe apache's httpclient
03:07	Fossi	hi
03:12	konr	HI, Fossi
03:40	sfuentes	chouser: so your scala adventures are over?
03:45	hiredman	~scala ((x: Int) => x + 1)(3)
03:45	clojurebot	Int = 4
03:57	hiredman	sfuentes: http://gist.github.com/199542
03:58	hiredman	or something like it
04:03	sfuentes	hiredman: thanks for the sample :)
04:05	hiredman	it maybe help to note that resources are loaded via the classpath and the classpath has little to do with filesystem locality
04:12	sgtzx	anyone using Enclojure here?
04:13	sgtzx	I am trying to learn Clojure while using Enclojure in NetBeans, but it is acting very strangely.
04:14	sgtzx	for example if I have (let [frame (JFrame. "Celsius Converter" ... then later I do (doto frame (.<I apply tab completion here and it seems to not be able to infer that frame is JFrame>
04:48	Fossi	wouldn't it make sense to make all io methods and java calls to use an implicit io!?
04:49	konr	How do I send a file using http.client? I'm using (File. "/foo/bar.jpg"), yet apparently the field is being dropped
05:04	spuz	LauJensen: hey
05:04	LauJensen	Hey spuz
05:06	spuz	Just running your brain sim now :)
05:06	LauJensen	How's it going?
05:06	spuz	There's a few things I didn't quite understand in your description though..
05:07	spuz	for example, you mention pmap, but where do you actually use it?
05:07	spuz	also, how does it work?
05:08	LauJensen	Second line in "step" is "pmap (fn [window]"
05:08	LauJensen	~def pmap
05:10	LauJensen	As you can see it splits the computation into bits which are passed to 'futures' running in their own threads
05:14	spuz	interestingly, it appears to be creating 2 more threads than there are available processors
05:17	yason	spuz: it's a common idiom: two processes per processor perform better in case the processes are less than 100% cpu-bound; otherwise it's just 50/50.
05:17	eevar2	I think processor count * 2 might have been a better choise
05:17	eevar2	granted, you get more context switches, but
05:17	yason	spuz: doubling, that is. Not +2, although if you have a dual-core system then it's probably *2 and not +2 :)
05:21	spuz	well, if you see the code for pmap, it sets n to numprocessors + 2. I'm not exactly sure what it does with 'n' after that but I assume that's the number of threads that is created...
05:28	spuz	LauJensen: also, could you explain what the step function does? I'm not quite getting the third line. Could you maybe expand it with an example of the input and output that goes into each part of the function?
05:30	LauJensen	spuz: I doubt I could you more input than what you get from setting the board dimensions to 3x3, re-eval 'board' and then do it step by step, you'll see how it is mapping windows on windows
05:30	spuz	ok good idea
05:35	sgtzx	LauJensen: brain sim is cool
05:35	sgtzx	LauJensen: you mentioned there is a performance hit due to that it's a functional language, how much do you think it is?
05:36	LauJensen	sgtzx: Glad you think so :)
05:36	LauJensen	With the current model, which is simple to reason about, the performance hit is huge, the way we work the board, the way the board is allocation, the massive allocation that comes with 'partition' and the strain on the GC that puts... Its a huge hit
05:37	LauJensen	I'm considering doing a revised version with blazing performance, but I figured I'd wait a few days and see what the commentators come up with :)
05:37	sgtzx	LauJensen: I would love to see that
05:41	sgtzx	LauJensen: out of curiosity, what IDE do you use, or do you use emacs and slime for clj dev?
05:41	vy	I'd expect concat to behave same as lazy-cat and there would appear no lazy-cat? Aren't they functionally identical, except laziness?
05:42	LauJensen	sgtzx: Emacs
05:43	LauJensen	,(class (concat 1 2))
05:43	clojurebot	clojure.lang.LazySeq
05:43	hiredman	,(first (concat [1] (println :foo)))
05:43	clojurebot	1
05:44	clojurebot	:foo
05:44	hiredman	,(first (lazy-cat [1] (println :foo)))
05:44	clojurebot	1
05:44	vy	So what's the difference between lazy-cat and concat?
05:44	hiredman	lazy-cat has an extra layer of laziness
05:44	vy	Ooops! lazy-cat is just a macro over concat!
05:45	vy	[& colls] `(concat ~@(map #(list `lazy-seq %) colls))
05:45	hiredman	concat is a function, so it's arguments are evaluated
05:45	hiredman	lazy-cat is a macro, so it controls the evaluation of its arguments
05:46	hiredman	which it does by wrapping them in a call to lazy-seq
05:47	vy	I'd still expect "concat" to work as "lazy-cat". Anyway...
05:48	hiredman	well, if you read the docstrings, the difference is explained there
05:48	hiredman	so I don't know why you would expect something other than what is documented
05:48	vy	Why would somebody prefer concat over lazy-cat?
05:49	hiredman	concat is a function
05:49	hiredman	so you can apply it
05:49	hiredman	etc
05:50	rsynnott	also, lazy-cat sounds like some form of lolcat
05:52	ambient	so does concat ;)
05:53	Fossi	repost (;-)): wouldn't it make sense to make all io methods and java calls to use an implicit io!?
05:55	jdz	Fossi: what is an implicit io?
05:56	hiredman	,(doc io!)
05:56	clojurebot	"([& body]); If an io! block occurs in a transaction, throws an IllegalStateException, else runs body in an implicit do. If the first expression in body is a literal string, will use that as the exception message."
05:57	vy	I'm reading clojure cheat sheet... While there appears "frest", and "rrest" in the documentation, there are no such functions supplied by the core, AFAIK. Am I missing something?
05:57	hiredman	the cheat sheet is old
05:57	hiredman	the are fnext and something else now
05:58	hiredman	rnext?
05:58	hiredman	,rnext
05:58	clojurebot	java.lang.Exception: Unable to resolve symbol: rnext in this context
05:58	hiredman	,nnext
05:58	clojurebot	#<core$nnext__3833 clojure.core$nnext__3833@1daa156>
05:59	vy	I love languages that are getting trimmed by time.
06:03	sgtzx	,nnext
06:03	clojurebot	#<core$nnext__3833 clojure.core$nnext__3833@1daa156>
06:13	jdz	there still is not any function like CL's find, is there?
06:15	vy	jdz: (first (filter f coll)).
06:15	jdz	vy: right.
06:20	liwp	any slime experts here?
06:21	liwp	if I type e.g. "(fn" into the repl and hit tab, I get a completion suggestion buffer and point has been moved in front of 'n' which I find really annoying
06:22	liwp	Is there a way to stop point from moving or can I somehow overwrite the 'n' when I carry on typing?
06:30	jdz	i don't observe the behaviour you describe...
06:31	LauJensen	jdz: phew - I thought something had happend to you, since I hadn't received a flamemail for my last blog post yet :)
06:32	liwp	jdz: urgh, I'll need to look into my slime setup then...
06:34	vy	liwp: Same as jdz in here.
06:35	liwp	vy & jdz: what do you get then? the completion buffer, but the point stays at the end of the line?
06:35	liwp	i seem to recall that I didn't see this behaviour sometime in the past, but I can't be sure
06:36	vy	liwp: Yup.
06:37	liwp	thanks
06:38	vy	Could somebody tell me more about the "with-local-vars"? I couldn't get the difference between "with-local-vars" and "binding".
06:45	liwp	vy: looking at the source it seems to me that with-local-vars creates new vars for the bindings, whereas binding rebinds the existing vars
06:45	liwp	I don't know what practical difference that makes
06:46	liwp	I guess if you call code in the body that uses global vars then with-local-vars will not work, i.e. it's not rebinding those global vars
06:49	pixelman	I'be been thinking about this lazy stuff -- does can clojure somehow cache stuff that's explicitly lazy?
06:50	yason	pixelman: what do you mean, like (memoize) ?
06:50	pixelman	I'm using compojure, and I would like to cache the result of certain calls to (html [...
06:50	pixelman	the app would be snappier
06:51	liwp	vy: and one major difference is that, as the doc string says, you have to use (var-get) and (var-set) to access the var in with-local-vars
06:51	pixelman	looking at memoize
06:51	vy	liwp: I see. Thanks. (Reading the sources...)
06:52	yason	pixelman: (memoize your-page-generation-fn) and store that somewhere
06:52	liwp	vy: with with-local-vars you can set the var value in the body with (var-set)
06:53	yason	liwp: what's the point in that, i.e. what can you do that you can't with binding?
06:53	pixelman	yason: pretty cool! will try that.
06:53	liwp	yason: dunno, I'm trying to figure it out ;)
06:54	yason	liwp: IIRC in Practical Clojure there was a paragraph that usually vars and symbols can be mingled together but for certain cases it's important to recognize the difference -- ain't figured that out yet :)
06:54	liwp	definitely one major difference is the fact that with-local-vars does not rebind vars globally (as the name suggests)
06:55	yason	liwp: hmmm, but (binding) isn't global either, right?
06:56	liwp	yason: if you call a function from the binding body that reads a var that you've rebound, you'll get the new value rather than the orig value
06:56	liwp	i.e. (def a 1) (defn foo [] a) (binding [a 2] (foo)) will return 2
06:58	liwp	,(def a 1) (defn foo [] a) (binding [a 2] (foo))
06:58	clojurebot	DENIED
06:59	liwp	,(do (def a 1) (defn foo [] a) (binding [a 2] (foo)))
06:59	clojurebot	DENIED
06:59	liwp	have it your way then
07:01	LauJensen	Does anybody know who's behind disclojure.org ?
07:02	yason	liwp: I know binding but an example of with-local-vars would be enlightening
07:04	liwp	,(with-local-vars [bb 1] (var-get bb))
07:04	clojurebot	1
07:04	liwp	are slightly useless example :)
07:05	liwp	the interesting bit is that you have to use var-get and var-set to access the var
07:05	LauJensen	nvm
07:29	pixelman	I'm looking for a logging framework, should I just use log4j or is there some wrapper or such for clojure?
07:30	lpetit	ataggart created one in clojure.contrib
07:30	LauJensen	pixelman: You can wrap log4j using 1 macro, and I recommend that approach :)
07:31	pixelman	tnx!
07:45	vy	LauJensen: Were you the one who was asking yesterday how to log to a file via c.c.logging?
07:48	LauJensen	No, but I remember the talk @ vy
07:51	vy	Then do you know the answer? I couldn't figure out it too.
07:51	LauJensen	To me the answer is using log4j , for you, it may be patching c.c.logging
07:52	vy	LauJensen: You mean directly using log4j without c.c.logging wrapper?
07:52	LauJensen	That's what I did
07:52	LauJensen	I'm not saying it's for you though, I just try to stay out of contrib as far as possible
07:58	pixelman	c.c logging worked fine when the loglevel was accepted by log4j but crashed when I tried a :notice. still pretty slick though. I just want to log some stuff. :)
07:58	Fossi	out of curiosity: why's that?
07:58	Fossi	LauJensen: out of curiosity: why's that?
08:00	LauJensen	Fossi: A lot of the code in contrib are small helpers/wrappers/utilities which help you abstract your problem - I get the best feel for the problem when I write these myself and sometimes that helps me refactor the code - if I didn't have all the code in my POV all the time, I don't think I'd refactor like I do, and I don't think I'd have as good a feel for it... and oh.. then there's the SQL thing :)
08:01	Fossi	understandable. in case you still look for new topics, i'd love a more elaborate blog post on that ;)
08:02	pixelman	what is the SQL thing?
08:02	LauJensen	I'm always looking for new topics :)
08:02	Fossi	kinda just explained the reasoning for the method of operation in the last few
08:03	Fossi	*to me
08:03	Fossi	ok, maybe that wasn't even an understandable sentence
08:03	LauJensen	pixelman: Kotarak and myself have developed ClojureQL which is a nice way to interact with databases, in contrib there's also an SQL wrapper, which I politically view as competition :) (just kidding)
08:06	pixelman	LauJensen: interesting, gotta look up your project :) I'm using the stuff in common now and finding it pleasant to use, but it's nice to see other approaches.
08:07	LauJensen	clojureql is radically different, because it lets you stick with your normal syntax, (query table1 [item id cost] (< cost 500)) for instance
08:07	spuz	LauJensen: very interesting, is that then just parsed and converted into normal SQL?
08:08	LauJensen	In some ways it's a matter of taste, in other we really provide functionality that you won't normally get, like specific backends for Mysql and Derby that provide FULL JOIN functionality etc etc, but read all about it on Gitorious :)
08:08	LauJensen	~clojureql
08:08	clojurebot	clojureql is http://gitorious.org/clojureql
08:09	LauJensen	Then that's saved as a syntax tree, which you can do stuff with, like (group-by foo (query table ...)) and when you ask to have it executed, it's transformed to a valid SQL string and run through JDBC's .nativeSQL, and then executed
08:10	pixelman	can I access data lazily from mysql?
08:11	LauJensen	Yep, (run con (query table [x y z])) gives you a lazy result-sequence, instead of LIMIT you can then do (take 50 ) on it, instead of OFFSET you can use (drop) but that's costly, we're still working on that. When you've fully realized the seq, the connection closes
08:11	LauJensen	(drop was costly, not limit)
08:12	pixelman	neat!
08:12	spuz	LauJensen: that's very nice
08:15	LauJensen	Glad you think so - My last blog post is already 8.th on Dzone.com, it's amazing the interesting functional programming/clojure is generating these days - wonder if Rich's JVM talk has something to do with it :)
08:15	snowwhite	Does clojure have classes?
08:15	Chousuke_	yes and no.
08:15	spuz	LauJensen: was that the one about OO and time?
08:16	snowwhite	Chousuke_, as in?
08:16	LauJensen	spuz: A functional Brians Brain simulator
08:16	Chousuke_	snowwhite: it has classes because the JVM has them; however, actually directly making classes yourself is not very idiomatic.
08:16	spuz	LauJensen: I mean the jvm talk, there was one called Are we there yet I think. Is that the one you mean?
08:16	Chousuke_	snowwhite: the ability to create classes is mainly used for interop with Java.
08:17	LauJensen	spuz: To my great disappointment I still haven't heard the talk(s) but I'm thinking the OO vs Time could be it
08:17	snowwhite	Chousuke_, Can you show an example by pasting some code somewhere?
08:18	Chousuke_	snowwhite: hm
08:19	snowwhite	Chousuke_, thanks
08:19	Chousuke_	I don't have a gen-class example at hand right now :/
08:19	snowwhite	Chousuke_, :(
08:19	LauJensen	~sofiaba
08:19	clojurebot	sofiaba is http://wiki.github.com/Lau-of-DK/sofiaba
08:19	LauJensen	snowwhite: I was forced to use gen-class in that :)
08:21	spuz	heh, I'm not sure a full blown 3d game is the kind of example snowwhite was looking for :p
08:21	Chousuke_	snowwhite: behind the scenes there are of course classes generated everywhere but you can accomplish quite a lot with Clojure without writing a single named class :)
08:21	LauJensen	I didn't implement Duke Nukem, so it's not full blown :)
08:22	Chousuke_	snowwhite: for example, every clojure function is its own class.
08:22	Chousuke_	snowwhite: but you don't need to care about that :)
08:22	snowwhite	Chousuke_, hmm, but a small example could clarify a bit more?
08:22	spuz	it's interesting to see the classes generated by clojure, I put a very simple example through a decompiler to see what the byte code was doing and there's a lot more going on behind the scenes than you might think
08:22	Chousuke_	,(class (fn []))
08:23	clojurebot	sandbox$eval__5228$fn__5230
08:23	Chousuke_	but of course, that's not very interesting to you.
08:23	Chousuke_	for interop, you can often use proxy too
08:24	spuz	snowwhite: have a look at this for more info on class generation: http://clojure.org/compilation
08:26	Chousuke_	snowwhite: for interop without gen-class, you can have code like (.addListener someswingthing (proxy [ActionListener] [] (actionPerformed [e] ...))) ... proxy generates a class implementing ActionListener, but you don't need to care about what exactly it is called :)
08:27	snowwhite	Chousuke_, cool
08:27	snowwhite	Chousuke_, :)
08:27	Chousuke_	I guess gen-class enters the picture when people in Javaland need to be able to use it directly (and not through an interface)
08:28	Chousuke_	or if you're implementing a main method.
08:55	Drakeson	is completion broken with slime + swank-clojure ?
08:55	Drakeson	or is it just my setup that's broken?
08:56	cschreiner	Drakeson: at the repl?
08:56	cschreiner	works fine
08:56	cschreiner	in the buffer, not so
08:56	cschreiner	(for me)
08:56	Drakeson	it doesn't comlete even in the repl
08:57	Drakeson	I updated everything couple of hours ago
08:57	cschreiner	did you first M-c k the file?
08:58	Drakeson	what is M-c k ? it is unbound here.
08:58	cschreiner	ah, C-c k, sorry
08:58	cschreiner	I'm sure you did
08:59	Drakeson	that's unbound, too
08:59	cschreiner	did you start slime?
09:00	Drakeson	sure
09:00	liwp	try C-h k TAB
09:00	liwp	in the repl
09:00	liwp	that should say that tab is bound to slime-indent-and-complete-symbol
09:01	Drakeson	liwp: it is.
09:01	jdz	LauJensen: i have not seen your latest blog entry, sorry
09:01	liwp	then I'm out of ideas :)
09:02	liwp	Drakeson: and it doesn't mentione any before or after advice?
09:02	Drakeson	well, if I could be sure that it is my setup that is broken, not the upstream ...
09:03	pixelman	what to use to read in config files? wrap properties? or yaml
09:05	liwp	pixelman: Properties can be dumped into a clojure map so it's definitely an easy way to get something working fast
09:06	Drakeson	liwp: I am trying to edebug the completion functions ...
09:06	liwp	,((into {} (System/getProperties)) "path.separator")
09:06	clojurebot	java.security.AccessControlException: access denied (java.util.PropertyPermission * read,write)
09:06	liwp	blah
09:06	pixelman	liwp: yep, that's nice
09:07	liwp	the downside is that the keys are strings rather than keywords
09:08	ambient	anyone have the problem that after running a swing app, slime disconnects and I have to restart/reload everything?
09:09	liwp	ambient: many swing apps bind the close button to System/exit which will then kill your JVM and the slime connection
09:09	liwp	it's very frustrating when running stuff via slime
09:10	LauJensen	liwp, can't you just override it ?
09:10	ambient	it's ok if i just comment out the EXIT_ON_CLOSE part?
09:11	ambient	i don't know how to lessen the amount balls i have to juggle in air while trying to code swing/clojure with emacs/slime/clojure-mode
09:11	liwp	ambient: I think so, I think the default behaviour is to close the window and that's exactly what you want
09:11	liwp	LauJensen: sure, it just annoys me when I try out someone's clojure/swing app and closing it kills my repl
09:12	LauJensen	ok :)
09:15	ambient	heh, searching for 15 minutes on how to indent clojure code in emacs and a simple mark region + press tab does it :D
09:15	ambient	my google-fu is seriously lacking
09:16	liwp	ambient: also M-x indent-region would work
09:16	Drakeson	press tab? use M-C-\ after marking region.
09:16	Fossi	Meta-Q
09:17	Fossi	indents the current region
09:17	Fossi	no selection needed
09:17	danlei	I most often use C-M-q at the start of a sexp
09:18	Fossi	yeah, sorry, meta-q is paredit-indent
09:19	liwp	Drakeson: thanks for that - I'll have to try to remember it in the future
09:20	liwp	M-C-q also sounds good although I usually don't have to re-indent clojure code
09:21	danlei	I nedd it all the time :)
09:21	danlei	*need
09:21	liwp	I'm not sure why I don't need it, maybe it's because of paredit or because my yank reindents the yanked code
09:22	danlei	hm, I use paredit too
09:22	liwp	maybe I just leave my code in a massive mess and don't notice it 8-I
09:22	Drakeson	I rarely need that (maybe I press TABs too often). I only do a few C-x h C-M-\ during the day.
09:22	danlei	:)
09:24	danlei	liwp: self-reindenting yank sounds nice
09:24	danlei	should make mine behave like that too
09:24	liwp	danlei: it's very good with e.g. C++ and friends when you move stuff out of blocks
09:25	danlei	sure is
09:25	liwp	I can't remember where I picked it up from, probably emacs wiki
09:25	Drakeson	ok, what does (slime-eval '(swank:completions "ma" "user")) produce?
09:26	Drakeson	it doesn't give me any completion, and results in: (nil "ma")
09:26	liwp	Drakeson: I get a whole list of stuff, e.g. macroexpansion-1
09:27	liwp	(("macroexpand" "macroexpand-1" "main-page" "make-array" "make-hierarchy" "map" "map-invert" "map-str" "map?" "mapcat" "match-method" "match-uri" ...) "ma")
09:27	Drakeson	liwp: thanks. now I know there is something wrong with either swank-clojure or my setup.
09:28	liwp	this is the main problem with emacs: things sometimes break and it's difficult to figure out what's broken simply because your emacs setup is unique in the world
09:28	danlei	liwp: something like (lambda () (yank) (save-excursion (exchange-point-and-mark) (indent-sexp))) should work for lisp code
09:29	pixelman	,(map #( list (keyword (% 0)) (% 1) ) {"foo" "FOO" "bar" "BAR"})
09:29	clojurebot	((:foo "FOO") (:bar "BAR"))
09:29	pixelman	how can I build a map instead?
09:29	liwp	danlei: isn't your mark going to be in the wrong place when you're yanking?
09:30	danlei	it's untested, but I think it should work
09:30	liwp	pixelman: with reduce
09:30	pixelman	liwp: ok!
09:30	liwp	pixelman: something like (reduce #(assoc %1 (first %2) (second %2)) {} ...)
09:31	liwp	danlei: the yank-indent hack that I use adviced the existing yank, I'll see if I can find the URL for it
09:32	danlei	liwp: thanks. my thingie works, btw
09:32	danlei	but it should do everything pasted, not only a sexp (although that's what I most often paste)
09:32	danlei	s/do/indent/
09:33	liwp	danlei: http://trey-jackson.blogspot.com/2008/03/emacs-tip-15-indent-yanked-code.html
09:33	danlei	liwp: thanks!
09:34	liwp	np
09:37	danlei	ah, now I see what you meant, should move to the beginning of the line, too :)
09:38	pixelman	,(reduce #(assoc %1 (keyword (first %2)) (second %2)) {} {"foo" "FOO" "bar" "BAR"})
09:38	clojurebot	{:bar "BAR", :foo "FOO"}
09:38	danlei	(or just press tab before yanking)
09:39	pixelman	liwp: thanks for the pointer :)
09:41	Chousuke	,(into {} (map (fn [[k v]] [(keyword k) v]) {"foo" :bar}))
09:41	clojurebot	{:foo :bar}
09:45	liwp	Chousuke: what's the best way to turn a java HashMap<String, String> into a clojure map with keyword keys?
09:46	liwp	i.e. we talked above about using Java Properties for config and I can turn that into a clojure map with into, but I'm left with String keys
09:47	liwp	I could use your above code to change the keys to keywords except that the items in a Properties object are not pairs
09:47	chouser	what's wrong with string keys?
09:47	liwp	chouser: you can't do (:foo my-map)
09:47	liwp	not a big deal, but still
09:47	Chousuke	liwp: you can do (my-map "foo") though :)
09:47	liwp	yeah, I know
09:48	liwp	and also, I guess some of the strings won't be legal keywords anyhow
09:48	rhickey	ah, finally! - http://www.infoq.com/presentations/Value-Identity-State-Rich-Hickey
09:48	Chousuke	(let [m {"foo" "FOO" "bar" "BAR"}] (zipmap (map keyword (keys m) (vals m))))
09:48	Chousuke	,(let [m {"foo" "FOO" "bar" "BAR"}] (zipmap (map keyword (keys m) (vals m))))
09:48	clojurebot	java.lang.IllegalArgumentException: Wrong number of args passed to: core$zipmap
09:48	Chousuke	hmm
09:48	Chousuke	ah, damn
09:48	Chousuke	,(let [m {"foo" "FOO" "bar" "BAR"}] (zipmap (map keyword (keys m)) (vals m))))
09:48	clojurebot	{:bar "BAR", :foo "FOO"}
09:49	Chousuke	I'm too used to paredit taking care of the parentheses :(
09:49	chouser	"Presented by Rich Hickey on Oct 01, 2009" Oops.
09:49	liwp	Chousuke: that'll work, thanks
09:59	spuz	What's the best way to add two vectors? I could do something like (map + [1 2] [3 4]) => (4 6) but this returns a list rather than a vector
09:59	Chousuke	just call vec on that :)
10:00	spuz	ok :)
10:00	spuz	I wonder if there is a more efficient way but we'll see if it is a performance problem later :)
10:01	ambient	vectors are often just arrays so you could use an actual array
10:01	Chousuke	arrays are mutable though.
10:01	Chousuke	vector aren't.
10:01	Chousuke	spuz: I don't think there's any more efficient way, besides using mutable data structures.
10:01	Chousuke	and you probably don't want that. :P
10:01	spuz	ok
10:02	ambient	using the GPU for numeric work
10:02	ambient	or dedicated math libs
10:14	namor	What is the advantage of STM over a synchronized "swap!" function?
10:14	chouser	namor: coordinated accees/mutation of multiple references.
10:15	liwp	namor: you can change multiple things as an atomic transaction
10:15	namor	Ok, i get it. Thanks.
10:16	raek	if I want to write yaml/load instead of org.ho.yaml/load (org.ho.yaml is a java package) how do I do it?
10:16	liwp	raek: import org.ho.yaml
10:16	liwp	yaml is the java class?
10:17	raek	no, the package
10:17	liwp	what's the clas?
10:17	raek	oh whait
10:17	raek	org.ho.yaml.Yaml is the class
10:17	raek	load is a static method of that class
10:17	raek	then there's no problem :)
10:17	liwp	ok
10:19	raek	user=> (Yaml/load in)
10:19	raek	- a
10:19	raek	- b
10:19	raek	- c
10:19	raek	#<ArrayList [a, b, c]>
10:19	raek	yay!
10:20	liwp	cool
10:21	liwp	is that all you have to do? Is the yaml lib easy to use from clojure?
10:21	raek	I have no idea... :) this is my first experience with yaml in clojure
10:22	raek	the java containers can be used with clojure's sequence library
10:23	raek	so traversing the yaml data shouldn't be any problem
10:24	konr	does (:import (java.awt *)) work?
10:24	Chousuke	no.
10:24	konr	Chousuke: hmm, is there an alternative?
10:25	Chousuke	no.
10:25	Chousuke	:)
10:25	chouser	konr: you're not going to use all the awt classes. Just list the ones you use.
10:26	somnium	it seems some libraries use def and namespaces to emulate mutable objects, though this is religiously discouraged. is there a run time difference between this and doing, for example, (ns config) (def config-state (atom {})) and using swap?
10:27	Chousuke	somnium: people expect defs to be immutable, or at worst thread-locally bound. :P
10:27	Chousuke	if it's an atom, it's explicit that it can change.
10:28	somnium	compojure defines an explicit redef that preserves metadata, for example
10:29	chouser	ew. really?
10:29	somnium	I'm new enough to lisp that I don't have any 'religious beliefs' about def, but I want to adopt best practices. I was just wondering if they're absolutely equivalent but one breaks convention and one doesn't
10:29	somnium	yeah, in control.clj
10:30	Chousuke	in any case, using def anywhere except top-level is wrong.
10:30	somnium	I'm not sure how it's used, they
10:30	somnium	also an immigrate macro but that just takes all the vars from a list of namespaces and puts them into one for convenience
10:31	Makoryu	Would it be possible to print warnings for any non-top-level use of def?
10:32	chouser	oh, I see. I think compojure's just doing that during app setup. That's slightly less evil.
10:32	somnium	I asked about doing that but was told it was absolutely evil and to use atoms :)
10:33	somnium	is there a way to list all the classes in a java package?
10:33	chouser	somnium: no
10:33	chouser	somnium: you can look at all the .class files in a directory or in a jar
10:36	somnium	hmm, thinking of a dirty way to do import org.foo.* by using the classpath to find all the classnames
10:37	somnium	anyway, under the hood, is evil-redeffing and atom swapping equivalent?
10:38	chouser	not quite
10:38	chouser	def uses a lock on the var. atoms do atomic-set-and-check
10:39	somnium	ok, so no reason not to use atoms when configuring state before launching the main loop to be explicit?
10:41	chouser	sure.
10:42	chouser	another benefit of using atoms is that if you decide later it needs to be a ref (to coordinate with other refs) much of your code will be very similar
10:42	chouser	replace swap! with alter, wrap in a dosync, done.
10:42	chouser	if you were redefing vars, you'd have to go find where you need to add @, fix your def calls, etc.
10:44	ambient	how do i refactor this into a shorter form? (Color. (bit-xor x y) (bit-xor x y) (bit-xor x y))
10:44	liwp	ambient: (let [c (bit-xor x y)] (Color. c c c))
10:44	ambient	ah.. slaps forehead
10:45	liwp	heh
10:45	somnium	I'm thinking of the way rails plugins go in and alter whatever core classes they're changing, it should be simple to decorate atoms with a logger to go and see exactly what happens during config
10:45	chouser	you wanted something trickier, perhaps. (#(Color. % % %) (bit-xor x y))
10:45	liwp	chouser: slightly shorter as well I think ;)
10:45	ambient	that seems oddly readable :o
10:46	liwp	(apply Color. (replicate 3 (bit-xor x y))) ?
10:46	chouser	plus it generates a whole new class for you under the covers.
10:46	spuz	chouser: I missed ambient's question, what is x and y?
10:46	ambient	image coordinates
10:47	ambient	xor function gives a cool image for testing purposes
10:48	spuz	heh, an image of what though :)
10:48	Fossi	xor
10:48	liwp	and x and y
10:48	Fossi	it plots the function :)
10:49	ambient	it's kinda the simplest fractal that i know of
10:50	spuz	I have a question, how can I get the decimal representation of a Ratio?
10:50	chouser	,(double 7/3)
10:50	clojurebot	2.333333333333333
10:51	spuz	chouser: thanks
10:53	rhickey	That infoq talk is one of my favorites
10:54	chouser	I'm watching it now. Did you just watch it?
10:54	rhickey	yep
10:54	rhickey	slight slide lag in a couple of places, but I love that they sync the slides like that
10:54	liwp	must be weird watching yourself give a talk
10:55	chouser	yeah, that's good practical tech.
10:55	liwp	rhickey: yeah, that's a really nice feature
10:56	Fossi	repost (again ;-)): wouldn't it make sense to make all io methods and java calls to use an implicit io!?
10:56	rhickey	Fossi: no, many are functional
10:56	rhickey	also overhead
10:56	Chousuke	rhickey: I just finished it. They cut out the question part at the end though (or were there really no questions? :/)
10:57	rhickey	they don't usually include the q/a part
10:57	rhickey	there were a few, Joe Armstrong was in the audience :)
10:59	Fossi	too bad :(
11:00	somnium	what's the url?
11:00	rys	Joe is the Erlang guy?
11:00	liwp	rys: yep
11:01	liwp	somnium: http://www.infoq.com/presentations/Value-Identity-State-Rich-Hickey
11:01	rys	Watched a nice thing with him and SPJ recently, can't rememeber the site though. InfoQ?
11:01	liwp	rys: this: http://www.infoq.com/interviews/armstrong-peyton-jones-erlang-haskell
11:01	liwp	?
11:01	liwp	I haven't watched it yet
11:01	rys	Yeah, that's the one
11:01	rys	It's quite funny
11:01	Chousuke	the thing about needing to model time hadn't quite sunk in before I watched that presentation, but I think it's clear now. good stuff, anyway
11:02	rys	Joe's really animated and SPJ just sits there, dead still
11:03	liwp	SPJ gets animated when he's launching missiles
11:04	sproingie	naw he's just lazy :)
11:04	liwp	;-)
11:27	spuz	rhickey: hey, just watching your qcon talk. You say you made a talk the previous day, what was that talk about?
11:27	rhickey	spuz: an introduction to Clojure
11:27	spuz	is that available somewhere?
11:27	rhickey	not yet
11:28	rhickey	the one they put up is the important one, new compared to all others
11:28	spuz	ok
11:28	rhickey	the intro has a lot of overlap with other talks I've given
11:34	spuz	rhickey: what kind of feedback do you get from people after these talks? Do you think you're winning the battle of converting people away from OO?
11:34	liwp	rhickey: should into be changed take multiple from collections as args? e.g. (into [] [1] [2] [3])
11:35	liwp	mark volkman was asking about it on the group
11:35	liwp	and is this an appropriate impl: (apply into (into x y) zs)))
11:38	rhickey	spuz: I think that talk was one of the more popular at QCon. There's a whole other set of issues in converting people... I'm not trying to do that, just explaining the ideas behind Clojure
11:43	rhickey	liwp: I'm not sure about multiple args, not that important. could use (reduce into dest [xs ys zs])
11:43	Drakeson	liwp: can I ask you when you last updated your swank-clojure ?
11:43	liwp	sure
11:44	liwp	Drakeson: not too long ago I don't think
11:44	liwp	rhickey: I was looking for low hanging fruit to contribute. Is there anything urgent in assembla that no one's looking at?
11:45	sproingie	speaking of converting people from oo, there a doc out there about functional ways to replace is-a relationships?
11:45	sproingie	i have a few tricks but it all feels pretty ad-hoc
11:46	rhickey	,(derive ::square ::rect)
11:46	clojurebot	nil
11:46	rhickey	,(isa? ::square ::rect)
11:46	clojurebot	true
11:46	ambient	square and rect are a good example of a devious not is-a relationship iirc
11:47	rhickey	liwp: anything marked for next release without patches is fair game
11:47	ambient	(a bit off-topic)
11:47	sproingie	square and shape then
11:47	rhickey	ambient: only in the face of mutation
11:47	liwp	Drakeson: maybe I haven't updated after all... git log gives me c1e309dfe53cb45149258404c4db5b53fb5c81b7 from april 17th
11:47	sproingie	the square/rectangle problem is a classic trick question. it _has_ no "right" answer
11:47	chouser	what?
11:48	rhickey	in what way is a square not a rectangle?
11:48	sproingie	if the contract for shapes says they have optional constraints, then there's a right answer
11:48	sproingie	one-arg constructor to square violates substitution principle
11:49	rhickey	sproingie: you don't have an object yet when you call the ctor
11:49	rhickey	so no substitution
11:50	sproingie	constructors usually aren't polymorphic anyway, so there's some argument that substitutability doesn't apply
11:50	sproingie	wonder what liskov would say to that
11:52	sproingie	been teaching myself scala for this whole week. love the syntax sugar, but soooooo much syntax.
11:52	sproingie	i'd probably be half-done with my project if i started it in clojure instead
11:53	Fossi	any language with a construct like +: 1 2 fails :D
11:53	Fossi	poor mans macros
11:53	somnium	I couldn't stand the syntax, too similar-yet-different to ruby
11:53	Makoryu	Fossi: Eh? What language would that be?
11:54	sproingie	eh my day job is perl, so i'm used to crazy syntax all over
11:54	Fossi	Makoryu: you could define +: as a prefix + operation in scala
11:54	Makoryu	Fossi: Ah
11:55	Fossi	the last char in the name defines the binding
11:55	Fossi	excellent idea...
11:55	sproingie	+: would define a right-associative infix operator
11:56	sproingie	you can't really define new prefix operators, they're hardwired to +-!
11:56	sproingie	oh and ~
11:56	Fossi	ah. well. same, same really
11:57	Fossi	pretty mad
11:57	vy	chouser: Any progress on " http://www.assembla.com/spaces/clojure/tickets/149-pop-does-not-preserve-meta-data (Actually, I'm just wondering the patch.)
11:57	vy	#149
11:57	vy	pop does not preserve meta-data
11:57	Makoryu	I still think the APL family has the craziest syntax
11:57	sproingie	i thought it was kind of crazy that ending with : would make a method right-associative. sort of flies in the face of what you'd expect for an operator that looked smalltalkish
11:57	Fossi	and absolutely overengineered and artificial
11:58	Drakeson	liwp: thanks.
11:58	Makoryu	Every function, regardless of the name, is either prefix or infix
11:59	sproingie	J makes perl look like cobol
11:59	Makoryu	Yep
11:59	liwp	Drakeson: yeah, I don't think I've upgraded since my slime-macroexpand-all work just fine. It got broken when some stuff got moved from contrib to core
11:59	liwp	although it might have been fixed now in swank-clojure head
12:01	chouser	vy: had totally forgotten about it
12:02	chouser	liwp: how's that for low-hanging fruit?
12:03	somnium	I wonder how hard it would be to emulate ruby semantics with clojure, wrap hash-maps with method missing, convert instance vars to atoms. maybe use \| as a delimiter instead of ; due to the reader.
12:03	liwp	chouser: I thought it would be relatively simple to implement
12:04	liwp	chouser: then I noticed that the current implementation special cases transients and I wasn't so sure anymore ;-)
12:04	chouser	ahhh. :-)
12:04	somnium	as an example for the conversion from OO battle. I'm assuming C-syntax to lisp and OO to functional are separate battles
12:06	liwp	chouser: if you don't mind calling (transient) and (persist!) separately for each collection then it's easy, but calling them only once for the into call requires some more thinking
12:09	liwp	how do i get git to tell me where my repo was cloned from?
12:16	weissj	liwp: look in .git/config
12:16	liwp	weissj: thanks. There's nothing like 'svn info'?
12:16	weissj	liwp: there might be a command to show you that as well, but i don't know what it it
12:16	weissj	is
12:17	liwp	ok, thanks
12:18	Chousuke	git remote show origin
12:20	liwp	Chousuke: thanks. I'm sure I've seen that before.
12:20	Chousuke	one of my favourite features of git is the ability to have multiple remotes
12:21	Chousuke	makes it easy to track multiple repositories :)
12:21	liwp	Chousuke: with clojure are you working with a direct clone of rich's github repository?
12:21	Chousuke	well, yes and no.
12:22	liwp	I had my own clone on github and I cloned my working copy from that, but I'm not sure if that's the right thing to do w.r.t. patches
12:22	Chousuke	I have rich's repo as origin but I have my own github fork as a remote called "public" :P
12:22	liwp	this is some sort of higher git magic that I haven't seen yet
12:23	Chousuke	it's not too difficult
12:23	liwp	so if you branch locally, do you push those branches then to your gh repo?
12:23	Chousuke	sometimes
12:23	Chousuke	some I keep local
12:23	liwp	that was my main reason for having my own clone on gh, that I could save my branches somewhere
12:24	Chousuke	if I make bugfixes and such I base them on origin/master but then for example my reader branch tracks public
12:24	liwp	makes sense
12:24	liwp	just yesterday I nuked my gh clone and now I'm thinking I should recreate it and do something similar to what you're doing
12:25	Chousuke	git help remote, then :)
12:25	liwp	yep, I'll need to do some reading
12:25	Chousuke	(well, actually it's just git remote add remotename url-here)
12:26	liwp	so you clone a working copy from rich's repo and then add another remote to it (for example)?
12:26	Chousuke	that's one way
12:26	Chousuke	the repos actually don't even have to be related :P
12:26	liwp	and is there some easy way to push branches back to the remote? I managed to make it work, but it didn't seem obvious to me
12:27	liwp	that makes sense, but is also slightly scary at the same time :)
12:27	Chousuke	git push remotename localbranch:remotebranch
12:27	Chousuke	you can also make a branch "track" a remote branch so that you can just "git push" and "git pull"
12:27	liwp	will that possibly give the branch a different name on the remote?
12:27	Chousuke	yeah
12:28	Chousuke	you can omit the :remotebranch if you don't need that
12:28	liwp	I think that's what I did last time (tracking), which is actually what I wanted
12:28	Chousuke	so most of the time just git push remote branch
12:28	Chousuke	many scary things are possible with git ;)
12:29	liwp	so a 'git push' after a 'git push remote branch' will not push the branch changes to the remote?
12:29	liwp	since the branch is not tracked?
12:30	Chousuke	correct. but you can always configure the defaults afterwards
12:30	liwp	that's nice
12:30	Chousuke	git config branch.<branchname>.remote and .merge or something IIRC.
12:31	liwp	so you would recommend keeping my own clone on gh? I tend to do stuff both at home and at work so being able to share the repo via gh is nice.
12:31	Chousuke	well, I won't recommend anything... but it's what I do. :P
12:31	liwp	I was just worried about patches in that scenario, but it seems that having rich's repo as another remote fixes that
12:31	liwp	:)
12:32	liwp	thanks, I'll think about it
12:32	liwp	gott go
12:32	liwp	s/gott/gotta/
12:33	Chousuke	even with just one remote patches will not be a problem... unless you let your clone get too old so that you end up fixing things that are already fixed :P
12:35	liwp	Chousuke: I thought that might be the case, but I wasn't sure
12:36	liwp	I thought maybe the diff wouldn't apply in some cases if there were subtle changes so it would be safer to produce patches against the main repo
12:36	liwp	anyhow, now I really gotta go :)
12:38	danlei	about remote brances: I find it more convenient to "push origin foo", "co master" "branch -f foo origin/foo" that way, everything tracking is setup correctly and one hasn't got to mess with git config ...
12:38	Chousuke	-f?
12:38	danlei	force, yes
12:39	Chousuke	ah, right.
12:39	Chousuke	well, that's one way
12:39	danlei	the other thing works as well, of course, but I find it more convenient like this
12:46	steiger	(contains? [[1 2] [3 4]] [1 2]) -> false . is it a bug?
12:48	Chousuke	no.
12:49	Chousuke	contains? doesn't test whether a value is in a collection
12:49	Chousuke	it tests whether said collection has a value for a certain key :)
12:49	Makoryu	, (contains? {:foo bar} :foo)
12:49	clojurebot	java.lang.Exception: Unable to resolve symbol: bar in this context
12:49	Makoryu	, (contains? {:foo 'bar} :foo)
12:49	clojurebot	true
12:50	Makoryu	, true
12:50	clojurebot	true
12:50	steiger	oh
12:50	steiger	I see
12:50	Makoryu	^ Is that defined as (def true 'true)?
12:50	steiger	the docs are a little bit confusing
12:50	Chousuke	Makoryu: no
12:50	Chousuke	Makoryu: it's special to the reader
12:50	Makoryu	Right
12:50	Chousuke	,(class true)
12:50	clojurebot	java.lang.Boolean
12:50	Chousuke	,(class 'true)
12:50	clojurebot	java.lang.Boolean
12:50	steiger	Chousuke: is there a function that tests wether a VALUE is present in the given collection?
12:51	Makoryu	,(class 'pizza)
12:51	Chousuke	hmm
12:51	clojurebot	clojure.lang.Symbol
12:51	Chousuke	steiger: I'm actually not sure about that.
12:51	hiredman	(.contains '(1 2 3) 2)
12:51	hiredman	,(.contains '(1 2 3) 2)
12:51	clojurebot	true
12:51	Chousuke	oh, right, the Collection method :)
12:51	hiredman	,(.contains '(1 2 3) 3)
12:51	clojurebot	true
12:52	steiger	hm, java contains
12:52	steiger	thank you guys
12:58	ben_m	Anyone have some example code for using sdljava with Clojure?
13:31	scottj	I often have trouble recognizing when to use map, reduce, loop, for, or lazy seqs that iterate or something. Anyone know of a tutorial (not necessarily in clojure, other functional languages would be fine) that focuses on helping imperative programmers to recognize when to use these methods?
13:31	ben_m	I've got a class Foo and a method bar that returns void (java interop). I'd like to create an object of Foo and call the method on it but return the created object, not the return value of bar ... is that possible?
13:32	vy	ben_m: What's wrong with (do (.bar foo) foo)?
13:32	ben_m	uh
13:32	sproingie	scottj: find out what the sources of events in your program are. now picture them as an infinite stream of events.
13:33	ben_m	vy: Not familiar with do, so I don't know. I'll look it up
13:33	sproingie	scottj: basically anything you can visualize as a timeline of state changes or events or messages or whatever you can convert to a sequence
13:36	sproingie	reduce is handy for consuming a stream whenever you need to keep the previous state handy. probably not as necessary with STM tho.
13:36	sproingie	*a stream of states
13:38	ambient	i wonder if asynchronous events will map 1-1 into seqs
13:39	ambient	it's something i've still yet to wrap my head around in fp
13:42	scottj	sproingie: thanks, but I guess what I'm looking for is a tutorial that breaks down common ways of using for/while loops and shows how to do them in fp
13:42	sproingie	you can block on a read of the event queue. there are probably better high-level constructs for that tho
13:43	sproingie	i'm not entirely sure what they are myself. i'm only halfway-FP myself :)
13:49	technomancy	scottj: reduce is for when you want one value from a sequence; map is to transform one sequence into another.
13:49	sproingie	scottj: you can always break down for/while into recursion, which we have loop/recur for
13:50	technomancy	scottj: for is just syntax-sugar for map
13:50	technomancy	doseq is like for, but intended for side-effects
13:50	sproingie	technomancy: reduce is also good when you never need the value back, but you want to derive the next action from the previous one
13:50	sproingie	you can get a pipeline by reducing apply over functions, for example
13:50	technomancy	sure
13:50	ambient	doseq doall and dorun still confuse me
13:51	technomancy	or when you need something more specific (map, set) than a seq from a sequence
13:51	sproingie	right, like for building a tree
13:52	sproingie	cons an empty tree onto the list and reduce the insert func over it
13:52	technomancy	sproingie: reduce takes an optional initial value; no need to conj it to the list
13:53	sproingie	yah i haven't translated all my idioms to clojure yet :)
13:54	ben_m	Is there something like an infinite loop in clj? (gameloop in my case)
13:54	sproingie	more useful with the optional arg since you don't have to screw up a nice homogeneous collection that way
13:54	sproingie	ben_m: a loop/recur with no base case
13:54	sproingie	or a for or reduce over an infinite sequence
13:54	chouser	ben_m: (fn [] (recur)) or (while true ...)
13:54	ben_m	Ah, didn't know while exists. Thank you :)
13:55	sproingie	or just plain while, yah. havent memorized the API yet :)
13:55	sproingie	ben_m: http://clojure.org/api
13:55	chouser	'while' is very rarely used
13:55	ben_m	I think the best way would be to use loop, since i'm using let anyways
13:55	sproingie	actually that probably doesn't have control structures in it, since those are usually special forms
13:55	chouser	but it yells "imperative" which can be useful
13:55	sproingie	but that page has a link to those
13:56	technomancy	anyone want to fix up swank-clojure's eldoc to indicate macros differently?
13:56	technomancy	or am I going to have to implement that myself? =)
13:57	sproingie	just don't infinitely loop by mapping over an infinite sequence. unless you like space leaks :)
13:57	chouser	map will just return a lazy seq and do nothing.
13:58	sproingie	something would have to consume that. which i guess can't be map.
13:59	chouser	right. would have to be something like (loop [xs (map ...)] (recur (next xs))) ... which wouldn't leak anything
13:59	Drakeson	what does (remove-ns 'swank.commands.completion) do at the begining of the file?
14:00	chouser	though it would churn memory needlessly.
14:00	chouser	(doc remove-ns)
14:00	clojurebot	"([sym]); Removes the namespace named by the symbol. Use with caution. Cannot be used to remove the clojure namespace."
14:01	Drakeson	it is being used before defining (na swank.commands.completion ...), and I don't understand the intent
14:03	Drakeson	(not to mention that swank completion is broken here, since the revision from around Sept 15)
14:04	technomancy	Drakeson: can you give an example of the breakage?
14:04	ben_m	Trying to do SDL programming with Clojure is pretty hard if you don't know Clojure that well and sdljava is pretty ... strange.
14:05	Drakeson	technomancy: I am looking at swank_c_p_c.clj, (a small file)
14:07	Drakeson	in the definition of `completions' there is a try..catch that aborts the completion in case of any error. I change it to actually see the error.
14:07	Drakeson	(well, I forget to say, the initial problem was that I was getting no completions)
14:08	Drakeson	the error message was this: "java.lang.IllegalStateException: Var swank.commands.completion/potential-completions is unbound."
14:08	sproingie	so when i hit C-c C-k in slime and it tells me there are errors, how do i make it actually show me the error?
14:08	technomancy	sproingie: they should be shown in the inf-lisp buffer
14:09	hoeck	ben_m: you can try processing, there is rosado's clj-processing, a thin clojure wrapper around it, using it with success for a small clojure space duel game
14:10	technomancy	clj-processing is awesome
14:10	ben_m	Oh, I've heard about processing.
14:10	ben_m	I'll take a look at it, thank you :)
14:10	technomancy	might not be as performant as sdl
14:10	sproingie	shown and then some. massive traceback obscures the actual error
14:10	ben_m	sdljava is a pain to use ... I'm getting a link error now for some reason
14:11	ambient	i could be possible just to use java sound and io api, plus straight opengl
14:11	ambient	or jmonkeyengine
14:11	Drakeson	I just copied the functions from swank.commands.completion into swank_c_p_c.clj, and it works. I just don't understand the mechanism that is supposed to load the stuff in swank.commands.contrib/
14:13	ben_m	ambient: Can't use OpenGL at the moment because my video card broke :/
14:14	ben_m	Else I'd probably use one of the available Java game libraries
14:15	Drakeson	is the line (remove-ns 'swank.commands.completion) at the begining of swank.commands.completion really necessary?
14:16	technomancy	Drakeson: my guess is that it's not necessary for regular usage, but it might be needed to hack on swank-clojure itself interactively
14:16	technomancy	I'm not too familiar with the completion mechanism though; I find that "dumb" dabbrev is enough for me
14:17	Drakeson	when I remove it, it can successfully load swank.commands.contrib.swank-c-p-c.
14:18	Drakeson	it is not really a matter of completion. I just don't understand what that defslimefn swank-require in swank/commands/contrib.clj was supposed to work.
14:18	Drakeson	it might be missing something
14:18	deafmacro	Hi! I tried righting "member?" to get a hang of using loop/recur. I would appreciate it if someone could review it. Here's the link http://pastie.org/639697
14:20	Chousuke	the x loop parameter is redundant :)
14:20	Chousuke	otherwise that should be okay.
14:21	Chousuke	though, (some (partial = x) coll) does the job :P
14:21	ben_m	How do I fix an UnsatisfiedLinkError?
14:22	ben_m	Do I miss something on the classpath, or .. ?
14:22	deafmacro	Chousuke: ah true :)
14:22	Drakeson	wow! I didn't know about java completion in swank ... that's neat.
14:23	technomancy	Drakeson: I heard about that but haven't gotten a chance to take a look yet
14:23	technomancy	imho that's much more valuable than lisp-level completion. =)
14:24	deafmacro	Chousuke: but I would still have to bind write (loop [coll coll] ... since it requires even args?
14:24	ben_m	I thought defn is like an implicit loop?
14:25	Drakeson	technomancy: it does not complete java.lang.Inte<TAB>, yet, but it completes java.lang.Integer/<TAB>
14:25	technomancy	cool
14:26	technomancy	is that using the same C-c TAB?
14:26	Drakeson	no, just TAB
14:26	technomancy	Drakeson: you must have rebound it; needs C-c TAB here
14:26	technomancy	TAB is for indentation. =)
14:26	Drakeson	well, I am in repl now
14:27	ambient	I do C-c I for Java classes, which inspects them. almost as good as completion, but not quite. don't know of a better way
14:27	technomancy	Drakeson: oh, gotcha.
14:27	technomancy	C-c I is really great too
14:32	deafmacro	Chousuke: never mind. figured it out. thanks!
14:37	durka42	deafmacro: you have a brilliant username. that is all.
14:53	ben_m	Is there a way to import everything from a namespace?
15:07	weissj	can someone recommend a library or strategy for storing clojure data in a db? i am working on a defect tracking system, one feature i intend to have is user-created record types, so it's a bit more dynamic than straight db tables.
15:08	weissj	i checked out clj-record, that might work for me, is there anything else?
15:09	tmountain	weissj: strategies for storing data, or data serialization?
15:09	weissj	storing data
15:11	weissj	the data structure isn't complex, but i want it to be dynamic - can remove fields from a record or add them during runtime
15:11	tmountain	weissj: AFAIK, clojure-contrib has a sql library (JDBC wrapper), there's persist (Java lib), and also Berkeley DB
15:11	tmountain	weissj: BDB is more of a key / value store IIRC
15:11	weissj	tmountain: yeah that's a bit too simple for my purposes
15:14	tmountain	weissj: have you seen datalog?
15:27	roberto_	ping
15:34	chouser	(.show (proxy [java.awt.Frame] [] (paint [g] (dotimes [y 256] (dotimes [x 256] (.setColor g (#(java.awt.Color. % % %) (bit-xor x y))) (.fillRect g x y 1 1))))))
15:36	chouser	also nice with bit-and or bit-or instead of bit-xor
15:46	crios	'night
15:47	ambient	how would i go about making a graphics element into a repl that i could asynchronously draw different stuff? like (start-graphics g) (draw-line g 10 10 20 20) etc...
15:50	chouser	ambient: (def g (.getGraphics (doto (java.awt.Frame.) .show)))
15:51	chouser	position that window so you can type into your repl with obscuring it
15:51	chouser	then: (.drawLine g 100 100 200 200)
15:51	ben_m	When I try to compile my program (clj -cp /usr/share/java/sdljava.jar sdl.clj) I get the following error: "Exception in thread "main" java.lang.UnsatisfiedLinkError: sdljava.x.swig.SWIG_SDLEventJNI.new_SDL_Event()J (sdl.clj:1)" Code: http://sprunge.us/KJJC
15:52	ambient	chouser thanks :)
15:52	chouser	ben_m: you have to have the swig-generated .so in your OS library path. I think that's the most likely cause.
15:53	ambient	my previous attempt was to draw a line (10 10 20 20) which I thought didn't work because it was drawn under the window border
15:54	ben_m	chouser: sigh ... :/
15:54	chouser	(.show (proxy [java.awt.Frame] [] (paint [g] (dotimes [y 256] (dotimes [x 256] (->> (+ (* x x) (* y y)) (* 0.01) Math/sin inc (* 127) int (#(java.awt.Color. % % %)) (.setColor g)) (.drawLine g x y x y))))))
15:56	ben_m	What's that ->>?
15:56	chouser	It's a macro a bit like ->
15:57	chouser	(->> a (foo b) (bar c)) becomes (bar c (foo b a))
15:57	chouser	that is, each expression is inserted as the last arg of the next expression
15:58	ben_m	Did you define it, or is that in Clojure?
15:58	chouser	it's new, in Clojure
15:58	ben_m	ooh :)
15:58	chouser	(doc ->>)
15:58	clojurebot	excusez-moi
15:59	chouser	too new for clojurebot
15:59	ben_m	too new for me too :)
16:12	hiredman	clojurebot: ant?
16:12	clojurebot	is equivilant to addresing the bot by name is equivilant to addresing the bot by name
16:12	hiredman	clojurebot: ant is dumb
16:12	clojurebot	You don't have to tell me twice.
16:13	hiredman	ugh
16:14	hiredman	I've started to see errors like java.lang.NoSuchMethodError: clojure.lang.RestFn: method <init>()V not found (fnparse.clj:1) everywhere
16:15	chouser	hiredman: clean and rebuild fnparse, probably.
16:15	hiredman	that was from starting clojurebot just now, but I have was seeing something very similar when trying to get ant to build something for appengine
16:15	hiredman	and fnparse was not used there
16:16	chouser	I see those all the time from contrib because I keep hoping between various versions of clojure.
16:16	chouser	hopping
16:17	hiredman	ah
16:17	hiredman	the error went away when I rebuilt contrib
16:17	hiredman	,(doc ->>)
16:17	clojurebot	"([x form] [x form & more]); Threads the expr through the forms. Inserts x as the last item in the first form, making a list of it if it is not a list already. If there are more forms, inserts the first form as the last item in second form, etc."
16:18	hiredman	damn
16:18	hiredman	sorry
16:18	kotarak	huh? ->>? hoorray!
16:21	chouser	, (->> (range 256) (filter #(or (<= 65 % 90) (<= 97 % 122))) (map char) (apply str))
16:22	chouser	oh, whoops
16:22	chouser	,(->> (range 256) (filter #(or (<= 65 % 90) (<= 97 % 122))) (map char) (apply str))
16:22	clojurebot	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
16:22	hiredman	handy dandy
16:22	ambient	,(* 0.01745329252 180)
16:22	clojurebot	3.1415926536
16:23	crios	clojurebot: logs
16:23	clojurebot	logs is http://clojure-log.n01se.net/
16:25	chouser	,(.show (java.awt.Frame.))
16:25	clojurebot	java.awt.HeadlessException: No X11 DISPLAY variable was set, but this program performed an operation which requires it.
16:25	chouser	oh, right.
16:27	crios	hi, I already posted this question but it seems it get lost in the net: did anyone read "Structure and Interpretation of Computer Programs", by Abelson, Sussma? If yes, do you think it could be an worth introductory "clojure" concepts textbook?
16:28	crios	[this one: http://mitpress.mit.edu/sicp/full-text/book/book.html]
16:28	ambient	i've read some of it and it has helped
16:28	johnmn31	when doing (defn add1 [x] (+ x 1))
16:28	kotarak	someone made a blog with translations of the code. (maybe the book-Stuart?)
16:28	crios	I believe, for a Java programmer an introductory "Lisp" world book would help
16:29	crios	thanks ambient
16:29	johnmn31	does this "expand" at runtime to (defn add1 ([x] (+ x 1))) ?
16:29	kotarak	crios: touch yourself scheme in fixnum days
16:29	kotarak	teach
16:29	hiredman	johnmn31: no
16:29	ambient	clojure doesn't just have functional style, it has immutable data structures and strong concurrency constructs
16:30	crios	kotarak: "fixnum days" ?
16:30	johnmn31	hiredman: well, defn "expands" to (def (fn [.. right?
16:30	ambient	crios it's going to take a lot of work (at least it did for me) to grok it all, but i think it's worth it
16:30	johnmn31	I mean (def foo (fn [...
16:31	crios	kotarak: I got it: http://www.ccs.neu.edu/home/dorai/t-y-scheme/t-y-scheme-Z-H-1.html
16:31	kotarak	crios: well, I didn't choose the title. ;) In Scheme numbers are stored in fixnums, that is in 32 (or 64) bit. When the grow larger they are saved in Bignums.
16:31	hiredman	johnmn31: yes
16:31	johnmn31	k thanks
16:32	arohner	is there a clojure.contrib fn for calling (read) on a string?
16:32	kotarak	crios: it's for Scheme, but that should be sufficient for lispiness.
16:32	hiredman	johnmn31: macroexpand and macroexpand-1
16:32	kotarak	,(doc read-string)
16:32	clojurebot	"([s]); Reads one object from the string s"
16:32	ambient	crios you've looked at this, right? http://java.ociweb.com/mark/clojure/article.html
16:32	arohner	kotarak: thanks
16:32	arohner	that's new since the last time I needed to do this
16:33	crios	ambient: yes, and read also "Clojure Programming". But I feel I'm missing something
16:33	ambient	just write some code
16:34	johnmn31	hiredman: tried that, but (macroexpand add1) didn't get me what I expected.
16:34	hiredman	johnmn31: that is not how you use macroexpand
16:35	kotarak	,(macroexpand-1 '(defn add1 [x] (+ x 1)))
16:35	clojurebot	DENIED
16:35	crios	ambient: yes, I write some code, but I feel I miss perhaps the right "conceptual" world's view - a shared vocabulary
16:35	ambient	sicp lectures were quite eye opening in some parts
16:35	johnmn31	ah, ok, I forgot the '
16:36	crios	ambient: ok, I'll read it (keeping to check also your blogs and chat, sure :) )
16:37	johnmn31	ahah! it does add parens:
16:37	johnmn31	(def add1 (clojure.core/fn ([x] (+ x 1))))
16:38	hiredman	but not in the defn form
16:38	johnmn31	so one could make mulit-arity lambdas as well then...
16:39	hiredman	sure
16:39	johnmn31	sweet
16:41	chouser	Revenue on T-shirt sales is rolling in at a steady clip of about $2.50 per month.
17:35	ambient	does clojure in future have some more revealing ways of communicating about errors?
17:36	ambient	im just having a bit of a difficulty in debugging
17:36	ambient	(which is happily easier in functional style because i can test each piece of my program separately)
17:40	arbscht	ambient: c.c.trace can help debugging in some cases
17:47	hiredman	wheee
17:47	hiredman	appengine app built (hello world page)
17:48	hiredman	and it runs on the local dev server thing
17:48	ambient	with clojure? grats
17:48	arbscht	compojure?
17:48	hiredman	yeah
17:48	arbscht	neat. a few people have been doing that lately
17:49	hiredman	the shellscript for launching the local dev server of course has #!/bin/bash but if you change it to #!/bin/sh it runs fine
17:49	ambient	hmm, i wonder how that works in windows...
17:49	ambient	probably not at all
17:49	hiredman	there is a seperate .cmd script for launching it on windows
17:50	ambient	got to try that someday soon
17:50	ambient	on my list of things to do
17:51	hiredman	I followed a howto I fould googling "clojure appengine"
18:07	somnium	hiredman: do you have the repl setup for it?
18:07	somnium	http://www.hackers-with-attitude.com/2009/08/intertactive-programming-with-clojure.html
18:08	somnium	it shows how to setup the appeninge api for the thread you run the devserver in, so you do live lispy development without any recompiles locally
18:09	ben_m	Alright guys, this is driving me insane.
18:10	ben_m	I've got /usr/share/sdljava.jar and a lot of *.so files in /usr/lib/sdljava/ ... I try to run a little example like this: clj -Djava.library.path=/usr/lib/sdljava/ -cp /usr/share/java/sdljava.jar SDL.clj
18:10	ben_m	When I leave out the -D line, I get an UnsatisfiedLinkerError
18:10	ben_m	When I include it, I get Exception in thread "main" java.io.FileNotFoundException: -Djava.library.path=/usr/lib/sdljava/libsdljava.so (No such file or directory)
18:11	ben_m	Without the libsdljava.so at the end, that was the wrong line I pasted, but yeah, same error
18:11	ambient	"/usr/share/sdljava.jar" "/usr/share/java/sdljava.jar" different directory
18:11	ben_m	ambient: I'm using the right ones when I try it, sorry.
18:11	ben_m	Just typed them here incorrectly.
18:13	ambient	are the binaries compatible?
18:14	ambient	JVM & libsdljava.so etc
18:14	ambient	i got some weird errors using 32 bit libs in 64 bit environment
18:15	ben_m	uhm
18:15	ben_m	All the .so files are 32bit libs, and I'm on 32 bit too.
18:17	ben_m	Errors + Source + commands I run: http://sprunge.us/ZdTU
18:21	ambient	i wonder how two -cp commands work in java executalbe, do they replace or concatenate
18:21	ambient	it might be in the clj script, just a thought
18:22	hiredman	yeah
18:22	hiredman	the clj script is trying to pash the -D stuff as a file name argument to java
18:22	hiredman	pass
18:22	hiredman	use java -Dwhatever directly
18:31	ben_m	I'll try.
18:33	ben_m	I get the same UnsatisfiedLinkError :(
19:24	somnium	is there support for variable arity multimethods?
19:27	arbscht	somnium: yes
19:28	somnium	could you give a simple example? I wasn't able to improvise the syntax
19:30	somnium	(defmulti foo (fn (....) (....)) and then (defmethod foo ([a] ...) ([a b] ...)) ?
19:31	arbscht	http://gist.github.com/200252
19:32	somnium	ah, thank you
19:56	rsynnott	anyone know is there a way to view repl history in enclojure with keyboard shortcuts?
20:01	danlei	ctrl+uparrow
20:02	danlei	(if you meant input hist)
20:03	danlei	plain pgup otherwise
20:06	rsynnott	ah, thanks :)
20:07	rsynnott	CTRL-SHIFT-UP on the mac, oddly
20:07	rsynnott	(I'm mostly an EMACS/slime person, but giving this thing a go)
20:08	danlei	I have it installed, but use emacs almost exclusively (wanted to know at least one alternative)
21:16	cschreiner	clojure needs to be distributed together with emacs as a one-install-package targeted newcomers
21:17	hiredman	~google clojurebox
21:17	clojurebot	First, out of 28 results is:
21:17	clojurebot	Clojure Box, alpha - Clojure \| Google Groups
21:17	clojurebot	http://groups.google.com/group/clojure/browse_thread/thread/6fd17fb97f058192
21:18	cschreiner	for mac?
21:18	arbscht	iirc, clojure-mode has an install routine that makes it quite easy to get started
21:19	cschreiner	arbscht: you're missing my point
21:20	cschreiner	it's too easy to get lost in emacs
21:20	cschreiner	but when you get use to it, it rocks the world
21:21	cschreiner	and when you are adding "common" components, like compojure, or this 3d thing, I don't recall; (penumbra?) you have to deal with the ugliness of classpaths, in addition!
21:22	Raynes	If you want to use Emacs, you're probably better being committed to learning Emacs, rather than wanting and expecting to be spoon-fed Emacs with a dumbed down installation. If you don't want to learn Emacs, Enclojure is always an option.
21:22	arbscht	I'm not convinced there is any way around that -- such is emacs. even if there was, it has little to do with clojure, which is independent of any editor
21:22	cschreiner	from the perspective of a beginner, this is daunting
21:23	albino	emacs is like any other piece of technology, the learning curve has a pay off
21:23	arbscht	a beginner would do well to learn emacs first, or avoid it altogether
21:23	albino	I would vote for avoidance so you're not trying to learn two big technologies at the same time, but that's just me
21:23	Raynes	arbscht: Exactky.
21:23	cschreiner	my point is to get up and running with clojure (with most of the libraries preinstalled) in as little time as possible
21:23	Raynes	exactly*
21:24	Raynes	cschreiner: Then you would want to just install Enclojure.
21:24	Raynes	Or Clojure-dev, or whatever.
21:24	cschreiner	but are they good?
21:24	cschreiner	and what about customization?
21:24	arbscht	they're suited to your constraint :)
21:24	Raynes	Enclojure is fine, Clojure-dev leaves a lot to be desired, and La Clojure is pretty good.
21:25	cschreiner	~google enclojure
21:25	clojurebot	First, out of 248 results is:
21:25	clojurebot	enclojure - home
21:25	clojurebot	http://enclojure.org/
21:25	Raynes	cschreiner: You need to decide what you want. Do you want superpowers and customization, or do you want to get up and running with Clojure really fast?
21:26	Raynes	You can't really have one or the other unless you're already an Emacs user. ;)
21:26	cschreiner	first up and running, then superpowers
21:26	cschreiner	everybody wants to have superpowers
21:26	cschreiner	most geeks anyway
21:29	cschreiner	enclojure seems to suit my needs, thx
22:25	Drakeson	how can I get a lazy random sequence?
22:28	chouser	,(take 20 (repeatedly #(rand-int 100)))
22:28	clojurebot	(45 59 66 15 15 27 40 4 29 10 74 77 17 99 17 12 13 33 31 83)
22:29	Drakeson	thanks
23:32	Drakeson	how can I apply a function to all vals of a hashmap and obtain a "transformed" hashmap?
23:33	chouser	,(
23:33	clojurebot	EOF while reading
23:34	chouser	,(let [m {:a 1, :b 2, :c 3}] (zipmap (keys m) (map #(* 5 %) (vals m))))
23:34	clojurebot	{:c 15, :b 10, :a 5}
23:35	Drakeson	right now I am doing (defn map-map [h f] (apply hash-map (mapcat (fn [[k v]] [k (f v)]) h))), which looks inefficient
23:35	Drakeson	chouser: thanks
23:35	Drakeson	is there a function for that?
23:39	kevin__	are (keys m) and (vals m) going to have a stable ordering?
23:42	slashus2	only in a sorted-map
23:42	slashus2	well..
23:44	kevin__	that's what i figured, so calling them seperatly to map a hash would be unsafe right?
23:46	slashus2	,(keys (apply hash-map [6 8 1 2 3 4 5 6]))
23:46	clojurebot	(1 3 5 6)
23:46	slashus2	I am not sure... hmm
23:46	hiredman	,(let [h {:a 1 :b 2} f (fn [f v] (reduce #(conj %1 [(key %2) (f (val %2))]) {} v))] (f inc h))
23:46	clojurebot	{:b 3, :a 2}
23:49	slashus2	,(keys (apply hash-map [:c 8 :a 2 :b 4 :d 6]))
23:49	clojurebot	(:a :c :b :d)
23:49	slashus2	,(keys (apply sorted-map [:c 8 :a 2 :b 4 :d 6]))
23:49	clojurebot	(:a :b :c :d)
23:50	ngoc	How to remove element from a hash? I can use "remove", but it is long way because it takes a function.
23:50	kevin__	,(let [h {:a 1 :b 2 :c 3 :d 4}] [(keys h) (vals h)])
23:50	clojurebot	[(:a :b :c :d) (1 2 3 4)]
23:50	kevin__	,(let [h (apply hash-map [:a 1 :b 2 :c 3 :d 4])] [(keys h) (vals h)])
23:50	clojurebot	[(:a :c :b :d) (1 3 2 4)]
23:51	hiredman	ngoc: dissoc
23:51	kevin__	same wrong order this time, i guess that's ok
23:51	slashus2	:-(
23:53	ngoc	hiredman: thanks
23:53	kevin__	i was concerned that since they were unordered, keys and vals might be unordered in different ways
23:54	kevin__	so if you zipmap'ed them back you would associate the wrong keys and vals
23:55	hiredman	some future IPMap migth do that
23:59	ngoc	hiredman: I also notice that "remove" changes the class of the hash to sequence
23:59	ngoc	(def h {:a 1, :b 2})