#clojure – 2009-11-10

2009-11-10

00:00	_ato	hmm
00:00	_ato	,(split-with #{" "} "foo bar")
00:00	clojurebot	[() (\f \o \o \space \b \a \r)]
00:00	_ato	,(map str (split-with #{" "} "foo bar"))
00:00	clojurebot	("clojure.lang.LazySeq@0" "clojure.lang.LazySeq@3f32ee98")
00:01	_ato	,(map #(apply str) (split-with #{" "} "foo bar"))
00:01	clojurebot	java.lang.IllegalArgumentException: Wrong number of args passed to: sandbox$eval--5184$fn
00:01	hiredman	…
00:01	_ato	,(map #(apply str %) (split-with #{" "} "foo bar"))
00:01	clojurebot	("" "foo bar")
00:01	_ato	nevermind
00:01	qed	there are also the str-utils clojure-contrib libs
00:01	qed	which have a re-split in them
00:01	hiredman	,(doc split-with)
00:01	clojurebot	"([pred coll]); Returns a vector of [(take-while pred coll) (drop-while pred coll)]"
00:01	_ato	h right
00:02	_ato	I was thinking of partition-by
00:02	_ato	which wouldn't have worked anyway
00:04	sudoer	what does the . mean here? (. parsedLogFlow start)
00:05	hiredman	. is the java interop special form
00:05	_ato	same as: (.start parsedLogFlow)
00:05	hiredman	or (parsedLogFlow/start)
00:05	_ato	call the .start() java emthod on paresedLogFlow object
00:05	hiredman	or possibly parsedLogFlow/start
00:06	hiredman	_ato: could be field access
00:06	_ato	ah yeah true
00:07	sudoer	I see, what is the point of it then?
00:07	sudoer	oh, so I can do oop with java?
00:07	hiredman	no
00:07	hiredman	it is for java interop
00:08	hiredman	(don't do oop)
00:08	wavis	does assoc return a sorted map when given a sorted map?
00:09	_ato	wavis: yes
00:09	wavis	cool. if it uses a custom comparator, that's also preserved, i presume?
00:09	_ato	yep
00:09	wavis	gracias
00:10	sudoer	what does it mean when you say java interop?
00:11	_ato	sudoer: interoperating with code written in java. for example using a java library in a clojure program
00:11	hiredman	,(Math/sqrt 25)
00:11	clojurebot	5.0
00:12	hiredman	,(macroexpand '(Math/sqrt 25))
00:12	clojurebot	(. Math sqrt 25)
00:12	wavis	,(.exists (File. "/etc"))
00:12	clojurebot	java.lang.IllegalArgumentException: Unable to resolve classname: File
00:12	wavis	,(.exists (java.io.File. "/etc"))
00:12	clojurebot	java.security.AccessControlException: access denied (java.io.FilePermission /etc read)
00:13	sudoer	ok, I understand
00:14	sudoer	am I supposed wrap those calls with dorun? I see java interop cored wrapped in dorun, I read the dorun definition, but I am not sure why I would use it
00:14	hiredman	uh
00:14	sudoer	sorry, im a clojure newb, I assume my question made no sense?
00:14	hiredman	right
00:15	hiredman	have you read the doc for dorun?
00:15	hiredman	,(doc dorun)
00:15	clojurebot	"([coll] [n coll]); When lazy sequences are produced via functions that have side effects, any effects other than those needed to produce the first element in the seq do not occur until the seq is consumed. dorun can be used to force any effects. Walks through the successive nexts of the seq, does not retain the head and returns nil."
00:15	sudoer	I am tryint to understand what this does: (dorun (. parsedLogFlow start) (. parsedLogFlow complete))
00:15	sudoer	trying to understand why dorun is used there
00:15	hiredman	sudoer: maybe a typo
00:15	hiredman	I would guess they meant to use do
00:16	sudoer	the code works
00:16	hiredman	sure
00:16	hiredman	but that could just be an acident
00:17	hiredman	it also looks like either old code, or code by someone not so plugged into the clojue community
00:17	sudoer	its a clojure newbie
00:17	hiredman	because of the direct use of the . form
00:17	somnium	the source for do run is shorter than its doc string
00:17	hiredman	:P
00:18	qed	how do i keep track of the number of times ive called a function, inside of a function
00:18	hiredman	…
00:18	hiredman	seriously?
00:18	qed	is that a stupid question?
00:19	hiredman	I guess it depends, but it kind of seems like it is
00:19	qed	i mean, here's the deal
00:19	qed	i have this function: (defn step [n] (if (even? n) (quot n 2) (+ (* 3 n) 1)))
00:20	qed	now i have another function that continues to call step until we can't go any lower
00:20	qed	err until we hit 0
00:20	hiredman	I know this problem
00:21	qed	i want to find out which number i input <1000000, that has the most number of steps
00:21	hiredman	iterate+filter+sort+count
00:21	qed	so im trying to determine how many steps something takes
00:21	hiredman	not filter. take-whil
00:21	hiredman	qed: like I said, I know this problem
00:21	qed	hey i believe you
00:21	qed	im just explaining my reasonining
00:21	qed	reasoning
00:22	qed	i dont really understand how to write what you're describing
00:23	qed	how does sort+count work?
00:23	qed	in this context
00:24	somnium	let me check my euler dir
00:24	qed	somnium: thanks, not trying to cheat if i can avoid it
00:24	qed	that's boring
00:24	hiredman	you sort the results of interate+take-while
00:25	hiredman	which will give you longest chain
00:25	hiredman	and the first thing in the chain will be the number
00:25	hiredman	odd, I can't find this in my euler.clj
00:26	somnium	its the collatz one
00:26	qed	oogatz
00:27	hiredman	clojurebot: hiredman's euler.clj?
00:27	clojurebot	euler is http://clojure-euler.wikispaces.com/
00:27	hiredman	bah
00:27	hiredman	clojurebot: hiredman's euler.clj
00:27	clojurebot	hiredman's euler.clj is so embarassing
00:28	qed	i wont be going there heh
00:28	somnium	all my solutions were painfully slow :(
00:28	somnium	but there's an easy bi... nm
00:28	technomancy	_ato: yeah, I'm going to make leiningen use build.clojure.org as a default repo before I hit up the release.
00:28	sudoer	hiredman: so is the dorun useless in that situation?
00:28	technomancy	_ato: all the functionality is there, it just needs a bit more polish, particularly in the bash script
00:29	hiredman	sudoer: it's hard to say, if those java methods return lazy-seqs that you want to realize for side effects it would make sense, but not otherwise
00:29	hiredman	and I doubt they do
00:29	qed	im not understanding tak-while
00:29	hiredman	I would guess they meant to use do
00:29	qed	(take-while (> 3) [1 2 3 4 5 6 7 8])
00:30	qed	how would i do that?
00:30	hiredman	qed: (> 3) is not a function
00:30	hiredman	so it would not
00:30	qed	(take-while (> [1 2 3 4 5 6 7 8] 3)) ?
00:30	hiredman	you need something like (partial > 3) or #(> 3 %) or (fn [x] (> 3 x))
00:30	hiredman	qed: no
00:31	qed	ah yes this partial business
00:31	somnium	qed: (take-while #(> % 1) (iterate (fn [n] (if (even? n) (/ n 2) (inc (* n 3)))) 9))
00:32	somnium	oops, meant to send that one to the bot
00:32	somnium	that gets you a function that returns an expansion, try to take it from there
00:33	qed	thanks somnium
00:33	qed	im off for the evening
00:33	qed	thanks hiredman and all for the help
00:46	twbray	Wondering if it's evil to use send-off with a placeholder first arg just because I want a long-running operation in its own thread. More idiomatic to just create a new thread?
00:50	_mst	twbray: `future' provides an easy way of spawning a new thread
00:50	_mst	,(doc future)
00:50	clojurebot	"([& body]); Takes a body of expressions and yields a future object that will invoke the body in another thread, and will cache the result and return it on all subsequent calls to deref/@. If the computation has not yet finished, calls to deref/@ will block."
00:50	twbray	_mst: Thanks, will check that out.
00:50	twbray	I guess I can just do (.start .... as well
00:51	wavis	,(send-off (agent nil) #(Thread/sleep 9999))
00:51	clojurebot	#<Agent@1aacdc9: nil>
00:51	wavis	i was expecting to be locked out of that one
00:51	_mst	yep, (.start (Thread. #(...)))
00:52	_ato	ah neat, scp uses a really trivial protocol so I can just make it talk to my own code that verifies the uploaded files and if they're okay puts them into the right place in the repo :)
00:52	twbray	wavis: (send-off (agent nil) makes me uncomfortable....
00:52	_ato	http://blogs.sun.com/janp/entry/how_the_scp_protocol_works
00:53	_ato	and that dispatch on ssh key thing that github does is easy too, you can just add a command=whatever to the end of each line in authorized_keys and it'll run it instead of the user's shell or scp or whatever :)
00:53	wavis	twbray: i suppose if you're starting with nil and want to immediately start initializing it, it could be practical. it does return the agent after all
00:54	_mst	_ato: yep, probably a good idea not to let them run whatever command they want ;)
00:54	shoover	twbray: I've seen several examples where an agent calls send-off on itself as a loop with a quit check. See the bottom section of http://clojure.googlegroups.com/web/ants.clj
00:55	twbray	shoover: thanks
01:00	hiredman	apache-mina has some kind of sshd in java
02:07	piccolino	Lazy sequences don't have to be infinite do they?
02:10	hiredman	nope
02:10	hiredman	,(map inc (range 10))
02:10	clojurebot	(1 2 3 4 5 6 7 8 9 10)
02:10	piccolino	I didn't think so.
02:10	piccolino	But then I'm having a hard time understanding what exactly lazy-seq wants. How do you terminate the sequence?
02:11	hiredman	nil
02:11	piccolino	Oh, OK.
02:11	hiredman	,(lazy-seq (cons 1 nil))
02:11	clojurebot	(1)
02:11	piccolino	I thought nil could be a part of a list, so I thought that would be alright.
02:11	hiredman	it's not really about what lazy-seq wants, but what cons wants
02:11	hiredman	,(lazy-seq (cons 1 '()))
02:11	clojurebot	(1)
02:12	hiredman	piccolino: nil can be part of a list
02:12	hiredman	but the second form in a cons is not an item in a list
02:12	hiredman	it is a list (or nil)
02:12	piccolino	Ah, OK. So you can't use lazy-seq with conj?
02:13	hiredman	never seen it done
02:16	piccolino	Man, this doc string still makes no sense to me. "yields a Seqable object that will invoke the body only the first time seq is called, and will cache the result and return it on all subsequence seq calls."
02:17	piccolino	How do I make an indefinitely long sequence that will definitely end at some point?
02:17	piccolino	I don't want the same expression called over and over, I need it work through some data.
02:29	hiredman	,((fn a [n] (when (not (zero? n)) (lazy-seq (cons n (a (dec n)))))) 10)
02:29	clojurebot	(10 9 8 7 6 5 4 3 2 1)
02:30	hiredman	usually you can get by with the various sequence functions with out resorting to lazy-seq
02:30	piccolino	Yeah, I was looking at iterate, but it says the function must be side-effect free.
02:31	hiredman	shurg
02:31	piccolino	I apprecite it, though, that's helpful.
02:31	piccolino	I find it confusing just what exactly lazy-seq returns and how it does its thing.
02:32	hiredman	lazy-seq returns a lazy seq
02:32	piccolino	Also, it requires recursion on a function?
02:32	hiredman	it's generally how it's done
02:33	piccolino	Yes, a lazy seq, but how exactly that contains my code, is what I mean.
02:34	hiredman	essentially you construct a list
02:34	piccolino	Like, in the cons in your lazy seq, if you call first on the lazy seq, clearly the cons has to be executed, but the second argument is deferred?
02:34	hiredman	the second are evals to a lazy-seq
02:34	hiredman	arg
02:34	piccolino	Oh, duh.
02:35	piccolino	I think I got it.
02:35	piccolino	Less magical than I thought.
02:35	hiredman	:)
02:45	piccolino	Urg. cons forces me to build it in backwards order.
02:47	piccolino	Oh nevermind.
02:48	Chousuke	lazy-seq is kind of cheating :)
02:48	Chousuke	"here, I'm consing to this sequence that doesn't exist yet"
02:55	piccolino	I have no idea how to explain it better, but I sure wasn't gonna understand that just from the docs.
03:01	wavis	If I create a function inside of a dosync, and the function references a ref, will the snapshot state of the ref be captured, or will, the function deref again later each time it is called?
03:01	tomoj	creating a function inside of a dosync sounds like a really bad idea
03:02	wavis	why?
03:02	tomoj	well, ok, not a _really_ bad idea
03:02	tomoj	compiling the function should have state side effects, it shouldn't need to be in a dosync
03:03	tomoj	try this
03:03	tomoj	(let [foo (atom 5)] (defn bar [n] (swap! foo + n)))
03:03	tomoj	then do (bar 3), (bar 4), whatever
03:04	tomoj	you don't need a dosync you just need to close over the state
03:05	tomoj	uh, also, s/should/shouldn't/
03:05	wavis	i hear you. the function doesn't have side effects though. i have to create a function inside, but I could create one that references the ref outside, and have the inside function call the outside function
03:06	tomoj	I dunno what you mean
03:07	wavis	so (let [a (ref nil) fa (fn [] @a)] (dosync (stuff) (fn [] (fa))))
03:09	wavis	fa gets the state of a
03:09	wavis	the function created in the dosync just calls fa
03:09	clojurebot	function is <Chouser> there is one class per fn, one instance of it per closure
03:09	tomoj	why do you need fa
03:09	tomoj	I mean, why can't you just put (fn [] @a) inside the dosync
03:10	wavis	that's the question. will calling that anonymous function return to the state of the ref inside of the original dosync, or will it deref the new state of the ref
03:11	tomoj	I still think wrapping a dosync around the fn is... strange
03:12	wavis	i'm altering a ref and setting it to (proxy [stuff] (stuff [])) ... i guess i could create the proxy outside the dosync
03:14	tomoj	I think the answer to your question is that it will be deref'd again and again
03:14	tomoj	creating the function doesn't store the value anywhere
03:14	tomoj	,(let [a (ref 3) fa (fn [] @a)] (dosync (alter a + 4) (fa)))
03:14	clojurebot	7
03:15	wavis	ok i'm going with that. It's what I intuitively expect, but I wasn't sure
03:17	wavis	,(let [a (ref 3) fa (fn [] @a) fb (dosync (alter a + 4) fa)] (dosync (alter a + 1)) (fb))
03:17	clojurebot	8
03:18	wavis	er. that actually doesn't do anything different. anyway...
03:19	wavis	,(let [a (ref 3) fa (fn [] @a) fb (dosync (alter a + 4) (fn [] @a))] (dosync (alter a + 1)) [(fb) (fa)])
03:19	clojurebot	[8 8]
03:19	wavis	there.
03:23	tomoj	yeah I don't understand the point of that at all
03:50	osaunders	Can you get a reference to the current function?
03:52	Chousuke	you can give it a local name as in (fn foo [] ... (foo ...))
03:52	osaunders	You can't not give it a name?
03:53	osaunders	I mean, you can't do it without giving it a name?
03:53	Chousuke	that's correct
03:53	Chousuke	there's no "this"
03:53	Chousuke	but the name is local, so if you need it there's no harm in giving it one.
03:54	Chousuke	it'll also make stacktraces more readable
03:54	osaunders	OK.
03:55	osaunders	You're only supposed to be able to def once right? If I def foo to 1 I shouldn't be able to def it to 3 again later. I should need set! to do that. Is the REPL an exception to that rule?
03:56	Chousuke	you can use def as many times as you want
03:56	Chousuke	you only shouldn't :)
03:56	osaunders	Right, OK.
03:56	osaunders	Because I was thinking that would be funny with recursion.
03:56	osaunders	Because if you have defs inside your function you'd re-def them each recursion.
03:57	Chousuke	yeah. and that would be horrible. :P
03:57	osaunders	If that wasn't allowed it might be a problem.
03:57	osaunders	Yeah.
03:57	Chousuke	defs anywhere other than top level are a problem.
03:57	sudoer	can I have multiple "classes" in a clojure file?
03:57	Chousuke	sudoer: gen-classed ones? not as far as I know.
03:58	sudoer	can I define java classes in a clojure file?
03:58	Chousuke	well, every function is a java class, so yes :P
03:58	Chousuke	but gen-class is for constructing custom classes.
03:58	sudoer	Chousuke: the code I have uses gen class
03:58	osaunders	Chousuke: Thanks for the help.
03:59	Chousuke	but often it's not needed. You can just use proxy.
03:59	yason	osaunders: you can use (binding) to "change" defs within a certain dynamic scope.
03:59	sudoer	I am totally new to clojure, I am trying to port this to clojure http://code.google.com/p/cascading/wiki/CrawlDataWordCountCascade
03:59	osaunders	yason: binding?
03:59	Chousuke	and there are a couple new things upcoming that you will be able to use to create "classes" :)
03:59	osaunders	You mean the [foo 1, bar 2] stuff?
04:00	osaunders	Wait, no.
04:00	osaunders	I really don't know :-P
04:00	sudoer	so can I just write it as regular java and have that included in my program?
04:00	yason	osaunders: it's one of Clojure's special forms
04:00	Chousuke	sudoer: no, not like that :)
04:00	sudoer	hmm
04:01	Chousuke	sudoer: if you have java code, keep it in a java file :P
04:01	sudoer	i dont even know how to program java
04:01	Chousuke	but you don't need to program java for that example.
04:01	sudoer	this is going to be tough!
04:01	Chousuke	you can implement the PipeAssembly subclasses through proxy
04:02	sudoer	Chousuke: what do you mean proxy?
04:02	Chousuke	(doc proxy)
04:02	clojurebot	"([class-and-interfaces args & fs]); class-and-interfaces - a vector of class names args - a (possibly empty) vector of arguments to the superclass constructor. f => (name [params] body) or (name ([params] body) ([params+] body) ...) Expands to code which creates a instance of a proxy class that implements the named class/interface(s) by calling the supplied fns. A single class, if provided, must be first. If not provid
04:03	sudoer	Chousuke: ok, I am reading about prozy now, my goal is to get this working today!!
04:04	yason	sudoer: check out some of the Swing demo applications for Clojure, they generally use proxy to implement event listeners
04:04	sudoer	Chousuke: have you programmed cascading before?
04:04	sudoer	so can I instanciate objects with proxy?
04:05	yason	sudoer: they look like real objects to Java
04:06	sudoer	can I declare the fake class though?
04:06	sudoer	or must they be classes that already exist?
04:07	yason	sudoer: you don't have to: just list the interfaces you want your proxy to emulate and implement whatever methods you know you'll need
04:08	sudoer	yason: how would I implement something like this where there are no methods, just the public interface? http://pastie.textmate.org/691616
04:09	sudoer	can I use proxy still for this situation?
04:10	yason	sudoer: You're eventually going to need an instance of PipeAssembly at some point?
04:10	sudoer	yason: of ImportLogAssembly, not directly of PipeAssembly
04:11	yason	sudoer: that's what you probably should proxy. In Java, you have to subclass something to implement your own stuff; in CLojure you proxy something to do that
04:12	yason	sudoer: but ImportLogAssembly is just a subclass of PipeAssembly; I would assume that some Java code actually needs to do something with the PipeAssembly since ImportLogAssembly is clearly an implementation of it
04:13	sudoer	so can I still proxy in this situation?
04:13	yason	sudoer: you generally don't want to replicate how the subclass hierarchy is generally built in the corresponding Java code. You want to narrow down to the essential interfaces/classes that you need in order to plugin to this framework
04:14	yason	sudoer: I don't know, I don't know enough about this PipeAssembly thing to know that.
04:14	sudoer	yason: yes, I will call this later: Pipe importPipe = new ImportLogAssembly( "import pipe" );
04:14	sudoer	yason: that means I must be really familiar with the underlying java code I guess
04:14	yason	sudoer: okay, so where is importPipe used then?
04:15	sudoer	yason: it gets called later like so: Flow importPagesFlow = new FlowConnector().connect( localPagesSource, importedPages, importPipe );
04:15	sudoer	yason: I am trying to port this example to clojure since I dont program in java: http://code.google.com/p/cascading/wiki/CrawlDataWordCountCascade
04:15	yason	sudoer: connect() method takes a Pipe right?
04:16	yason	sudoer: not PipeAssembly?
04:16	sudoer	yason: it appears so, yes
04:17	yason	sudoer: so you probably want to proxy a Pipe so that you can do your own stuff with the pipe object
04:17	yason	sudoer: but it seems to me that your example is a really bad one as for porting to clojure
04:18	sudoer	yason: its not a good fit? why is it bad?
04:18	yason	sudoer: it seems to be mostly about how java does things; you would want to know what the hell that mess is _supposed_ to do and implement that in Clojure, in a clean way
04:19	yason	sudoer: Java defines lots of classes and instantiates lots of objects because it has to. I almost never do that in Clojure because I write Clojure, not Java. I've only used proxy for Java interoperations and I try to minimize the interop parts of my code
04:19	yason	sudoer: so the question is how to solve the same problem that Java code solves, instead of how to write that Java code in Clojure
04:20	sudoer	hmm, unfortunately there is only one example of cascading and clojure used together and it was written by a clojure newb
04:21	sudoer	and I'm a newb to both clojure and java
04:21	somnium	porting java to clojure without being familiar with either sounds like a painful endeavor
04:22	yason	sudoer: you could learn the basics of Java first, say I/O and file operations. Then write that in Clojure.
04:22	sudoer	yeah, haha
04:22	sudoer	i mean I know basic java, but I really do not enjoy programming in java at all
04:23	sudoer	i wrote some apps for android a couple of years ago
04:24	yason	sudoer: I don't like Java either so I like to keep it to the minimum.
04:24	yason	sudoer: well take some very basic java program that only relies on the standard libraries and doesn't come with its own framework or anything, and try to do the same in Clojure
04:24	sudoer	i dont know any of the idiosyncrasies of java because I dont use it every day, I try to avoid it as much as possible
04:25	sudoer	yason: yeah, that is probably a good idea
04:25	Chousuke	most of that code seems to be news anyway
04:25	sudoer	or I could bite the bullet and write java for now, that would probably be the fastest route
04:27	somnium	FWIW, thinking of java as garbage-collected C helps me find it more tolerable ;)
04:27	Chousuke	hm.
04:27	sudoer	somnium: objective c!
04:28	somnium	hmm, I think I'd rather have objective c if given the choice
04:28	Chousuke	those extended assembly classes are silly
04:28	Chousuke	they only have a constructor that calls a super method at the end :/
04:29	yason	sudoer: how about just writing clojure and looking up Java as you go, on a need-to-know basis? That's what I practically did.
04:29	sudoer	yason: I want to write it in clojure
04:30	yason	sudoer: so pick a problem that's generic and not in the Java problem space
04:32	Chousuke	looks like you can replace them with a function like (defn make-import-log-assembly [the-name] (let [p (PipeAssembly.) regex (RegexSplitter. (Fields. "url" "raw")) import-pipe1 (Each. name (Fields. "line"), regex) import-pipe2 (Each. import-pipe1 ...)] (.setTails p result-pipe) p))
04:33	Chousuke	hopefully.
04:33	Chousuke	if PipeAssembly is abstract... :-(
04:33	Chousuke	Is proxy capable of defining the constructor?
04:34	sudoer	Chousuke: that is a clojure question, not question about cascading?
04:35	somnium	Chousuke: have you been using the new features?
04:35	sudoer	Chousuke: I think it is abstract : http://www.cascading.org/javadoc/cascading/pipe/SubAssembly.html
04:36	somnium	I tried gen class, but it was 10x times slower than 100 lines of java
04:36	yason	Chousuke: I don't know but constructor in a proxy doesn't really make any sense because there's no object for you to construct.
04:38	somnium	~proxy
04:38	clojurebot	proxy is <Chouser> proxy teases with its ease of use, then suddenly betrays.
04:38	Chousuke	somnium: gen-class itself is not the problem.
04:38	somnium	yes, the function lookups and state I guess? at any rate, it will be wonderful if we can get java speed without ever touching java
04:38	Chousuke	somnium: it creates a plain java class. it's the clojure code that's slower, because it's more dynamic and using primitives is more difficult :)
04:39	Chousuke	it can be optimised, but it's not very easy to match java speed. not yet, at least.
04:39	Chousuke	defclass etc. are supposed to help with that
04:46	somnium	does recur compile down to a for-loop? the code I needed just looped along a hashmap subclass, if (x typeof y) PersistentFoo.create() ... but I didn't know how to optimize the clojure version
04:47	somnium	(using clojure.walk probably didn't help)
04:47	Chousuke	did you eliminate reflection?
04:49	somnium	it didn't touch java much, I just used #^hashmap.keyset which had strings and the rest in clojure
04:51	Chousuke	that would be #^HashMap$KeySet :)
04:51	somnium	it seemed the java was faster at creating clojure objects than clojure, though its entirely likely my clojure code was poor
04:51	somnium	yes, I don't actually recall :) just only one direct java call and then condp instance?
04:51	somnium	I probably used #^Set or something
04:52	Chousuke	Oh well, I need to hurry away now. later.
04:52	somnium	bye
04:52	sudoer	Chousuke: one question about regular java: importPipe = new Each( importPipe, new Fields( "url" ), new RegexFilter( ".*\\.pdf$", true ) ); <--- isnt that a bad writing style to rewrite teh variable with the same variable?
04:53	Chousuke	sudoer: well, I think it's icky
04:53	Chousuke	certainly is in clojure, because it doesn't actually overwrite the old reference
04:53	Chousuke	it just shadows it.
05:28	ordnungswidrig	hi
06:16	AWizzArd	~seen cemerik
06:16	clojurebot	no, I have not seen cemerik
06:17	AWizzArd	~seen AWizzArd
06:17	clojurebot	AWizzArd was last seen in #clojure, 0 minutes ago saying: ~seen AWizzArd
06:26	Kjellski	I´ve got a question about the clojure bit-mapped hash tries: When we add one new thing, the path to that thing need
06:26	Kjellski	s to be created.
06:27	Kjellski	So, the pathes to every other thing begfore is just copied from old nodes?
06:27	Kjellski	I´m talking about these slides: http://clojure.googlegroups.com/web/ClojureConcurrencyTalk.pdf?gda=59CHlkwAAAB9TgGpbzbMg0BCq3i8IqXnCz2xnAVnahGaLFuwC71R5C1I1OtZCnFmn_w8aWW3nzHB8Gzz9WpxuUbp_zNxpCdh_Vpvmo5s1aABVJRO3P3wLQ
06:28	Kjellski	Page 21
06:28	_ato	Kjellski: what do you mean by "every other thing" just the path to the node you add needs to be copied
06:29	Kjellski	I know, but the pathes to the old nodes, where do they come from? Do we just copy old path and add one entry to the bottom node?
06:30	Kjellski	In other words: Is the copied path to the new node, a "java cloned" path that has all its entries and we´re adding one entry to the last one...?
06:32	_ato	Kjellski: oh right. No the whole path has to be changed, not just cloned... as each copied node in the path will have a different address
06:33	Kjellski	But Why? Wouldn´t it be just fine to copy every "not leaf" nodes until we get to the one that needs the new one?
06:35	Kjellski	chouser: Are you arround? ^^
06:35	_ato	suppose the path is nodes a b c. suppose our nodes currently look like a = [x b w], b = [c e r], c = [d e f]
06:36	_ato	we want to add a new value to node c
06:36	_ato	we create a new node C' with [d e f g]
06:36	_ato	but Clojure's data structures are immutable
06:36	_ato	so we can't just change b and a to opint at it, so we need to copy them too
06:37	_ato	so we make b' = [c' e r] and a' = [x b' w]
06:37	_ato	a' becomes our new referene to the data structure
06:39	Kjellski	Huh? a and b never changed. What I mean is just, looking at the picture of page 21 from the slides, our references in your example, to the xw and er and rf nodes, come from the old ones right? Our dashed lines to the shared structure, can be copied from old nodes...
06:40	_ato	yes, so x w don't change, but a and b need to because there's a new version of c, then there needs to be a new version of b that points at the new c, and thus there needs to be a new a to point the new b
06:41	Kjellski	Okay... that makes sense... sorry... I think I´ve got it. Thanks!
06:42	Kjellski	Do you know how "big" the node Objects are?
06:43	_ato	at most they have 32 entries, but they're only as large as they need to be
06:43	_ato	(plus wahtever java's normal object overhead is, probably 8 bytes or so)
06:44	_ato	also the tree is really shallow, because each node has up to 32 branches
06:44	_ato	so the paths that get copied are really short
06:47	Kjellski	I think that is pretty neat. ^^
06:50	ol3	hello, i am searching for a pathname-type method
06:50	_ato	yeah, they're pretty amazing.
06:51	ol3	is there something like that in java?
06:51	Kjellski	What is a pathname-type method?
06:51	_ato	ol3: is that a CL thing? what does it do, return the file extensions?
06:52	ol3	it returns the type of the file, normally the file extension
06:55	_ato	as far as I know there's nothing built-in to do that
06:55	Kjellski	And in the not normal case?
06:55	Kjellski	Why not just split at the last dot of path?
06:55	_ato	,(last (.split "foo.txt" "\\."))
06:55	clojurebot	"txt"
06:56	_ato	,(last (.split "foo.tar.gz" "\\."))
06:56	clojurebot	"gz"
06:56	_ato	,(next (.split "foo.tar.gz" "\\."))
06:56	clojurebot	("tar" "gz")
06:56	_ato	hmm
06:56	_ato	splitting extensions is hard because of cases like that :(
06:57	ol3	yes, that will work
06:57	ol3	,(.substring "foo.bar" (+ (.lastIndexOf "foo.bar" ".") 1))
06:57	clojurebot	"bar"
06:57	ol3	but split looks better
06:57	ol3	,(last (.split "foo.tar.gz" "\\."))
06:57	clojurebot	"gz"
07:06	ol3	,(doc file-seq)
07:06	clojurebot	"([dir]); A tree seq on java.io.Files"
07:06	ol3	,(file-seq "/")
07:06	clojurebot	java.lang.ClassCastException: java.lang.String cannot be cast to java.io.File
07:06	ol3	,(file-seq (java.io.File. "/"))
07:06	clojurebot	java.security.AccessControlException: access denied (java.io.FilePermission / read)
07:06	ol3	,(file-seq (java.io.File. "./"))
07:07	clojurebot	java.security.AccessControlException: access denied (java.io.FilePermission . read)
07:07	ol3	(take 1 (file-seq (java.io.File. "./")))
07:07	ol3	,(take 1 (file-seq (java.io.File. "./")))
07:07	clojurebot	java.lang.RuntimeException: java.security.AccessControlException: access denied (java.io.FilePermission . read)
07:33	stephenj	~def let
07:54	stephenj	~def pmap
07:59	stephenj	~def split-at
08:07	stephenj	~def future
08:26	Guest35930	I'm struggling to get with-out-writer in duck-streams to give me new lines when I (println ). How do I do this?
08:28	tomoj	Guest35930: it should already do that
08:30	Guest35930	Oh yes, it does! Notepad just isn't showing it. :)
08:30	tomoj	maybe it's a windows \r\n problem?
08:31	tomoj	e.g. maybe if you did (println "\r") instead it would work? I dunno
08:31	Guest35930	Quite probable, I'm on an XP machine at the moment. I'll give that a try.
08:37	stephenj	Guest35930: Does the answer look different if you open it in Wordpad (rather than Notepad)?
08:38	stephenj	Wordpad handles \n and presents it well - whilst Notepad insists on \r\n data
08:39	Guest35930	stephenj: Wordpad shows the intended output.
08:40	stephenj	Guest35930: So depending on which tool / environment, the output needs to adapt (or not)
08:41	stephenj	Depend on what the desired results is...
08:41	Guest35930	Well I'm planning on feeding this file to a DOS program, so I probably need \r\n?
08:42	stephenj	probably
08:42	stephenj	Sorry, must leave now - hope that helped
08:43	Guest35930	It did indeed, cheers.
08:50	Guest35930	It did require the \r. Thanks for the help tomoj.
08:53	tomoj	I wonder if there is a good way to automatically add \r
09:49	Kjellski	Is there any AI - Clojure approaches out there? Some libs?
09:49	Kjellski	-s
10:10	hamza`	hey guys, i have two maps, i would like to get a list of common keys right now i am using reduce to iterate map1 check map2 and build a vector? is there a better way to do this?
10:12	chouser	any nil or false values in either map?
10:12	hamza`	no they are a list of movies and scores
10:13	hamza`	* a map of
10:13	chouser	,(let [m1 '{a 1 b 2 c 3} m2 '{b 2 d 4 c 3}] (filter m1 (keys m2)))
10:13	clojurebot	(b c)
10:14	chouser	probably doing essentially the same work as you described -- walking through one map, looking up each key in the other
10:14	hamza`	wow, thx thats a lot shorter then reduce..
10:15	chouser	yw
10:36	tomoj	I feel bad wrapping up and hiding clojure.test/is
10:36	tomoj	but I don't like it very much either
10:36	tomoj	:(
10:37	chouser	what do you dislike?
10:37	tomoj	it just feels awkward to me
10:37	tomoj	trying to translate things like "response.should have_content"
10:38	tomoj	(is (has-content? response "foo")) works but seems... yeah, awkward
10:38	tomoj	maybe I'm just not used to it yet
10:39	chouser	I've got very shallow experience with testing frameworks, so I don't have much opinion.
10:39	chouser	is "response.should have_content" from an existing framework/language?
10:43	cemerick	I'm guessing that's ruby
10:43	cemerick	has a distinct AppleScript taste to it.
10:43	cemerick	or, rails, I should say
10:44	chouser	Assuming 'response' is a application object, having a 'should' method seems a bit odd
10:45	rys	smells like rspec to me
10:45	cemerick	right, I was keying on the 'response' bit -- doesn't rails use rspec?
10:45	rys	And if it is, it's response.should have_content("string") I think
10:46	rys	Although I haven't coded any ruby in an age
10:47	rys	Ah, yes, that's what chouser said upstream
10:48	cemerick	I'm sure an rspec-esque test framework could be put together. Not sure I'd use it, tho. :-)
10:55	tomoj	yep, it's rspec
10:55	tomoj	rspec puts a should method on everything :/
10:58	kefka`	Question about clojure.contrib.pprint: is there an easy way to set a left margin?
10:59	kefka`	,(+ 1 2)
10:59	clojurebot	3
10:59	kefka`	(just making sure I'm connected; ERC is acting weird)
10:59	kefka`	Anyway, I'm looking to set a left-margin in clojure.contrib.pprint
11:07	johny	hi
11:07	johny	what's wrong with my installation : http://paste.lisp.org/display/90105 ??
11:07	johny	the agent example does not return properly
11:10	tomoj	johny: nor does mine
11:10	chouser	johny: once the agent thread pools are used, clojure.main isn't sure all the work is done yet, so won't quit automatically
11:11	chouser	(doc shutdown-agents)
11:11	clojurebot	"([]); Initiates a shutdown of the thread pools that back the agent system. Running actions will complete, but no new actions will be accepted"
11:11	AWizzArd	cemerick: good that you suggested to continue the fixing in Contribs logging module.
11:13	cemerick	well, what's right is right. Some may worry about the fact that the solution would result in a deref call on every log, but I have to think it's worthwhile.
11:14	cemerick	I suppose we could add an init fn to the ns, but that's just kicking the can down the road.
11:16	johny	when 'i'm using await it also waiting forever if not message was sent
11:16	johny	is it a normal behavior ?
11:16	rhickey	I am considering protocols on interfaces being specified on a per-method basis, rather than (defprotocol AProtocol :on AnInterface ...)
11:17	rhickey	this because: there will often be a name remapping
11:17	rhickey	and, if there are extant interfaces, a single protocol might map to more than one
11:17	rhickey	the tradeoff is it is more verbose in the 1:1 case
11:19	rhickey	(defprotocol AProtocol
11:19	rhickey	"A doc string for AProtocol abstraction"
11:19	rhickey	(bar [a b] "bar docs" :on AnInterface/barMethod) ...)
11:19	chouser	johny: (let [a (agent nil)] (await a)) returns instantly for me
11:21	chouser	rhickey: renaming will be common because 'bar' will be a namespace-global name of a function while barMethod is an instance method on a specific class?
11:21	johny	(def node0 (agent 0)) (await node0) does not for me
11:22	chouser	johny: at a repl that returns instantly for me as well. What version of Clojure are you using?
11:22	AWizzArd	cemerick: yup, i absolutely agree and hope this will be fixed.
11:22	rhickey	chouser: could be for many reasons - you want to say my-fn here and myMethod there, or are mapping to a pre-existing interface with names you don't like
11:23	chouser	rhickey: will there be protocols on protocols, or is there even any value in that?
11:23	johny	1.0.0
11:23	rhickey	chouser: no protocols on protocols, share impls by mixing in method maps
11:24	johny	calling it with "java -cp /opt/clojure/clojure.jar clojure.main /tmp/simpleagent.clj"
11:24	chouser	rhickey: defprotocol doesn't provide any impls anyway, right?
11:25	johny	and with java 1.5.0_13 , maybe too old ?
11:25	rhickey	chouser: I'm still not sure about :on, the multiple interface case might be fabricated, and the name mapping could go in a single map
11:25	rhickey	chouser: right, no impls in defprotocol
11:25	sharvie	Hi, anyone know how to do the equivalent of ruby's respond_to? in clojure?
11:25	chouser	rhickey: anyway, so :on would only be needed for interop cases, either consuming or providing a Java interface.
11:26	rhickey	(defprotocol AProtocol :on AnInterface :mapping {this-fn thatMethod ...} ...)
11:26	johny	same pb with 1.6 :s
11:27	rhickey	chouser: :on is for extension via interfaces - could be a bout mapping to existing, allowing for extension via Java, or just fast-path (since deftypes could implement)
11:27	rhickey	the :on interface will be a fastpath
11:27	rhickey	tested first
11:28	chouser	rhickey: what about using the top-level :on as default, but allowing per-method :on to for renaming and disambiguation.
11:28	cgrand	and regular interop will use "implements", right?
11:29	chouser	I like having each defproto's method named once, rather than having to repeat it for the renaming cases.
11:29	rhickey	cgrand: maybe (extend AType AArotocol a-method-map BProtocol b-method-map ...)
11:31	rhickey	chouser: if top-level :on then I don't think per-method could be anything other than name mapping (i.e. not to introduce another interface)
11:32	rhickey	(a-method [args] "docs" :maps-to aMethod) or something
11:32	sharvie	exit
11:35	cgrand	rhickey: most of the time when you write (defprotocol AProtocol :on AnInterface ...) AnInterface will be an interface also written by the protocol author, no? Or are you thinking of retrofitting existing clojure interfaces (eg mapping IPersistentCollection/cons to conj)?
11:37	rhickey	cgrand: I don't want to decide this one way or the other - I am presuming both will occur with equal frequency (protocol author defines interface, protocol author maps to existing interface to allow for extension via protocols)
11:37	cgrand	ok
11:37	rhickey	obviously in the first case you have more control, but still might need mapping just due to Java name limitations
11:39	rhickey	so if top-level :on and name inside, need better name for :maps-to (a-method [args] "docs" :maps-to aMethod
11:42	chouser	I don't understand why top-level :on preclude per-method interfaces if per-method interfaces could ever be an option.
11:44	rhickey	chouser: because it would be too confusing
11:44	chouser	oh
11:45	rhickey	seeing A Protocol :on AnInterface leads one to believe implementing that interface is sufficient
11:45	rhickey	whereas the name mapping is more of an implementation detail, given good names and docs on the interface side
11:47	rhickey	I guess :maps-to could just be :on again
11:48	chouser	allow for a list of interfaces at the top level, and for any conflicting method names require a per-method :on ?
11:49	rhickey	chouser: I've pretty much talked myself out of mapping to more than one interface, barring a real use case
11:49	chouser	okey-doke.
11:49	rhickey	so, :on in method for name-mapping?
11:50	lisppaste8	cgrand pasted "grouped by interface" at http://paste.lisp.org/display/90109
11:50	chouser	sure
11:50	cgrand	forget that then :-)
11:52	chouser	I could use a way to refer to a clojure ticket in a contrib commit.
11:59	qed	sigh -- i just re-read the bipolar lisp programmer essay
11:59	qed	that is me to a T
12:03	tomoj	qed: sounds like me a bit too
12:06	tomoj	at least the "abject failure" part :)
12:18	qed	tomoj: haha -- no i can just relate to the boredom, the bad grades feeling surrounded by phonies, etc.
12:26	Knekk	Intensity: yuck
12:31	Knekk	yeah, that was #wrong
13:34	tomoj	wow, I got enlive's selectors working with the DOM tree from HtmlUnit
13:34	tomoj	I didn't think it would be this easy :D
13:36	hiredman	htmlunit++
13:36	cgrand	tomoj: cool! Did you use a custom zipper?
13:37	tomoj	uh, should I have? :/
13:37	tomoj	I just took the dom tree from htmlunit and made xml/element structs out of it
13:38	tomoj	gonna put the dom elements from htmlunit into metadata so that I can use your slick selectors and then take the results and do htmlunit-ish things to them like clicking/form-filling/etc
13:38	cgrand	no, I don't think that a custom zipper would be enough
13:38	tomoj	well I don't even have that :O
13:39	tomoj	I admit enlive is still mostly a mystery to me
13:46	cemerick	rhickey: is the only JVM lang summit video coming out the short stuff on youtube now, with bad audio?
13:54	rhickey	cemerick: It was recorded by InfoQ, I expect their usual v. good treatment eventually, but it is usually several months between event and release
13:55	cemerick	ah, ok
13:55	cemerick	I was excited to see some video, but figured there had to be something better coming.
14:01	chouser	So far this month the most frequent poster to the google group has over four times as many posts as the person in second place.
14:02	cemerick	chouser: you should post the top ten every month or something. :-
14:02	cemerick	:-P
14:03	rhickey	chouser: yes, how do you tell someone nicely that they need not participate in every discussion?
14:03	technomancy	along with Clojure's position on the Github languages high-score board. =)
14:03	technomancy	(which, btw, just surpassed Scheme to take position 20.)
14:05	rhickey	technomancy: do they produce a sorted list anywhere?
14:05	technomancy	rhickey: no, but I had a script somewhere to build one.
14:06	technomancy	if you're curious: CL is 19, Scala is 18, and Erlang is 17
14:06	danlarkin	The top10 is here: http://github.com/languages
14:07	djork	wow that's a very different picture than SourceForge
14:07	cemerick	I wouldn't have thought github would be attractive to CL folk.
14:08	chouser	It seems likely that the impression people have of a community could be influenced proportionally to the volume posted that portray various personalities and attitudes.
14:09	rhickey	hrm, richhickey/clojure is the most watched and most forked Java project this week/month/overall !?
14:09	rhickey	so isn't contributing to Clojure stats I guess
14:10	chouser	rhickey: I assume that's correct. contrib drives the clojure stats
14:10	danlarkin	rhickey: http://github.com/richhickey/clojure/graphs/languages
14:10	chouser	haha! http://github.com/richhickey/clojure-contrib/graphs/languages
14:11	shoover	You could always make core.clj more verbose
14:11	rhickey	I guess cinc will fix that
14:11	chouser	apparently contrib is written mostly in javascript
14:11	rhickey	heh
14:11	chouser	er, largely
14:23	replaca_	kefka`: are you there still?
15:26	Maddas	Looks like Github doesn't know about Fortran, Ada, or Cobol :-/
15:27	Maddas	Oh, it does know Fortran.
15:31	Chousuke	No Ada? :/
15:31	technomancy	Maddas: http://p.hagelb.org/github-langs.clj.html
15:32	hiredman	(ha ha VimL)
15:33	Maddas	technomancy: Thanks, I found a list on the site itself too.
15:33	technomancy	Maddas: you're not the only one! =)
15:36	Chousuke	Is Arc actually still being developed?
15:36	technomancy	no
15:40	Maddas	Paul Graham also forgot about it? =)
15:41	hiredman	http://groups.google.com/group/unladen-swallow/browse_thread/thread/4edbc406f544643e <-- I wonder if this means google is looking for another dynamic language
15:41	hiredman	I imagine they'd end up with rhino though
15:43	cemerick	rhino is really far behind on AOT compilation, last I knew
15:44	rhickey	hmm, I missed this last week: http://fwierzbicki.blogspot.com/2009/11/leaving-sun.html - so JRuby and Jython guys all gone from Sun now? That's really too bad
15:44	rhickey	cemerick: more likely js than rhino in particular
15:44	rhickey	given V8
15:45	cemerick	right, I forgot they had their own internal vm
15:46	headius	rhickey: I feel for the folks still at Sun, actually
15:46	rhickey	headius: I can imagine it's simply awful, waiting like this
15:46	headius	when we left in july we didn't like the idea of the axe hanging for a couple more months
15:46	chouser	I'm under the impression Paul Graham is still using and possibly making improvements to arc.
15:46	fogus_	technomancy: Paul Graham does still work on Arc... he blasted me about implying otherwise. :O
15:46	headius	now it could be year(s) what with the EU objection
15:47	rhickey	headius: yes, amazing
15:47	headius	the oracle/sun deal has probably done more to set back java platform dev than anything in the past decade
15:47	hiredman	:(
15:47	headius	rhickey: btw, I want to try writing a plugin for Duby that adds first-class lang support for clojure refs, collections, and stm
15:48	rhickey	cool
15:48	headius	I'll ping you when I get some time to work on it
15:48	cemerick	has anyone played follow-the-money on the EU thing? I doubt there's principled objections involved.
15:48	cemerick	headius: that's quite a quote
15:49	headius	cemerick: and you can feel free to quote me
15:49	headius	before this deal I might have said "JavaFX has probably done..." :)
15:49	chouser	heh
15:56	chouser	hiredman: VimL's not just there, it's above Emacs Lisp and all the other lisps.
15:57	chouser	hm. I've got a literal UTF-8 string in a .clj file that when written out to a data file is having it's multibyte characters replaced by question marks.
15:58	chouser	oh, I bet it's FileWriter's fault.
16:00	chouser	ah, and it worked when run from the command-line because my default encoding there is UTF-8, but when run from cron it must be something else...
16:02	hiredman	chouser: :(
16:02	hiredman	yegge should do something about vim's scripting language while he is doing something about emacs
16:03	chouser	he doesn't believe in vim because the smart people don't use it
16:03	hiredman	chasing down all the places where you have to set the checkbox to "UTF-8" is a pain
16:03	hiredman	chouser: :(
16:03	hiredman	could be true, I guess
16:04	fogus_	pg uses vim, that must count for something right?
16:04	jabley	fogus_: beat me to it
16:04	chouser	oh, does he? I didn't know that.
16:04	chouser	he uses etherpad.
16:04	fogus_	etherwhat?!?
16:05	fogus_	That's soooo last week
16:05	chouser	heh
16:06	chouser	http://etherpad.com/ep/pad/slider/foundervisa -- PG using etherpad
16:16	hiredman	clojurebot: git fbacc4a5751fa5c15baa599b5a058cd81b05a247
16:16	clojurebot	Added bound-fn to define thread-local binding aware functions bound-fn captures the thread-local bindings in effect where the function is defined. Installs these bindings before executing the body. This is useful for helper functions running in a different thread. Excluded with-bindings from clojure/main.clj to prevent name clash. Fixes #170 Signed-off-by: Chouser <chouser@n01se.net>
16:17	hiredman	whee
16:21	djpowell	do you think clojure's println and stuff should be respecting platform newlines?
16:22	hiredman	what do mean?
16:22	jbendig	\n versus \r\n?
16:23	hiredman	but, how exactly?
16:23	djpowell	yeah
16:23	hiredman	what if I want a literal \n on windows?
16:23	djpowell	(def nl (System/getProperty "line.separator"))
16:23	chouser	(prn-str) should return "\r\n", "\n" or "\r" depending on platform
16:23	djpowell	well it shouldn't rewrite \n's
16:23	chouser	?
16:23	djpowell	chouseer: yes
16:23	djpowell	er sry typo
16:24	hiredman	djpowell: so, again, "what do you mean?"
16:24	djpowell	hiredman: println and prn should output a platform specific newline at the end of the line
16:24	hiredman	oh
16:24	djpowell	any literal \n's will remain #x0a
16:24	hiredman	simple enough
16:24	hiredman	I though it did that
16:25	djpowell	not sure - i think it doesn't ?
16:25	hiredman	~def prn-str
16:25	hiredman	failure to render correctly in firefox
16:26	hiredman	ah
16:26	hiredman	~def newline
16:27	djpowell	actually, make a line-ending dynamic var, so you can rebind it if you want unix outputting on windows or whatever
16:28	hiredman	you can dynamically rebind newline to a fn that returns the line.separator property
16:33	djpowell	how are you supposed to use err btw? rebinding out to it?
16:36	chouser	djpowell: sure, or just write to it (.write err "error text\n")
16:38	djpowell	yeah, but then you miss out on some stuff like auto-flushing, and er newline handling
16:38	djpowell	i noticed that clojure.main printlns to err, which is making some assumptions about what class err is
16:39	chouser	indeed. won't work if err is an integer for example.
16:39	djpowell	only PrintWriters support .println, and if you're rebinding, you probably don't want to be using a printwriter, cause they eat exceptions
16:39	djpowell	ho ho
16:39	chouser	:-) sorry
16:39	hiredman	,(doc err)
16:39	clojurebot	"; A java.io.Writer object representing standard error for print operations. Defaults to System/err, wrapped in a PrintWriter"
16:50	spuz	I'm trying to write a paint function that draws on a BufferedImage, however as the paint method is called from Java, it cannot have the image passed into it as a parameter. Also as I don't know the width and height of the image until runtime, I can't define it as a var. How could I use something like dynamic binding to first create the buffered image and then access it in a paint function?
16:51	spuz	I've tried something like:
16:51	spuz	(def img) (defn draw [] (set! img (create image))) (defn paint [graphics] (drawImage graphics *img))
16:52	spuz	but apparently, you are not allowed to re-bind a var with set! until it has been initially bound
16:54	chouser	you'll implement the paint method using proxy?
16:57	_ato	spuz: use a closure when you make your proxy, like? (let [image whatever] (proxy [whatever] [] (paint [g] (draw g image))))
16:57	spuz	chouser: yes
16:58	_ato	if image isn't created at that point, or you need to change it, then make it an atom/ref
17:00	_ato	hmm is it just me or is everyone receiving 7 or 8 copies of each mailing list post? either google groups or my smtp server seems to have gone crazy
17:01	_mst	hm, no weirdness for me
17:02	_ato	hmmm.. it looks like it's google groups, there's different timestamps for the duped messages by their SMTP servers, oh well
17:04	shoover	spuz: using binding somewhere on the call stack, then you can set! if you want: (def img) (defn draw [] (binding [img (create-image)] (let [g (create-graphics)] (paint g)))) (defn paint [g] (drawImage g img))
17:05	spuz	shoover: hmm thanks
17:11	the-kenny	Is there a library like contrib.server-socket, just for client-sockets?
17:14	patrkris	Could Clojure get some of the benefits of Erlang if the JVM still supported green threads? I'm thinking for massively concurrent scenarios, where the overhead of context switching would be large.
17:17	hiredman	patrkris: I think it's telling that green threads are not used alot these days
17:18	hiredman	mostly because smp with native threads is less complex
17:19	patrkris	hiredman: yeah, well ... but shouldn't you be able to gain something without the context switching? I'm not suggesting to use only green threads instead of OS threads, but for highly concurrent scenarios, it may be nice to use green threads
17:19	patrkris	The same idea that Stackless Python uses
17:20	patrkris	As far as I know, Stackless Python uses green threads, and it is one of the reasons it is used for Eve Online, which exhibits concurrency on a massive scale
17:20	hiredman	well, python is horrible at concurrency anyway
17:20	hiredman	so, uh, any example with python is a deviant case
17:21	patrkris	well, yeah there are problems with the global interpreter lock and so on
17:22	hiredman	actually, the wikipedia article on green threads says that native threads outperform green threads for context switching on linux
17:22	patrkris	really... i'll check that out
17:22	hiredman	patrkris: as I said, I am aware of python's limitations in that regard, so I don't need you to repeat them to me :P
17:22	patrkris	sorry
17:24	hiredman	and explaining why python is bad at concurrency does not make it less bad
17:24	spuz	patrkris: Scala has erlang type concurrency, I'm not sure whether it uses green threads though
17:25	patrkris	hiredman: i was just mentioning stackless python as an example of a system that uses green threads - not trying to advocate python in particular
17:25	hiredman	spuz: it doesn't
17:54	hiredman	the invokedynamic pdf on hackernews uses the word "reified"
17:54	hiredman	first time I've seen it outisde of #clojure
17:54	hiredman	:P
17:58	djpowell	you hear it a lot with RDF
17:59	spuz	djpowell: RDF?
18:00	djpowell	spuz: http://www.w3.org/RDF/
18:00	hiredman	In the Core Reflection API, the simulation signature 〈as(),rs()〉 is
18:00	hiredman	always 〈Object[], Object〉. JRuby has about 8 simulator signatures,
18:00	hiredman	and Clojure has about 21.
18:00	hiredman	interesting
18:01	djpowell	spuz: a data model for representing information (on the web) as graphs with an xml seralisation and stuff
18:01	hiredman	I am subscribed to something called planet rdf
18:02	hiredman	"In a nutshell,
18:02	hiredman	function pointers have arrived in the Java virtual machine"
18:03	spuz	is invokedynamic actually going to appear in 7?
18:04	hiredman	yeah
18:05	hiredman	it's in, whenever 7 chooses to make an appearance
18:06	spuz	well this paper is way too heavy going for me, but maybe someone will write a blog post as to what it actually means :p
18:06	hiredman	I suddenly have a feeling that rich's protocol work and invokedynamic are connected
18:06	hiredman	spuz: the paper or invokedynamic?
18:06	hiredman	there are a lot of blog posts on invokedynamic
18:06	spuz	hiredman: both
18:07	spuz	yeah I've seen a few but I think haven't properly understood the context
18:14	replaca_	Rich makes no secret of the fact that he is voraciously following other developments in academia, the JVM, etc.
18:15	hiredman	sure
18:16	hiredman	I just hadn't caught onto to protocols+invokedynamic yet
18:17	Chousuke	that paper is quite interesting.
18:17	Chousuke	haven't even finished reading page three yet though. But so far it has been :P
18:19	hiredman	the paper is over my head too
18:21	hiredman	I like the fact that the paper is java java java λ calculas
18:28	_ato	hehe the java syntax for it is pretty horrible (like the curried greeter example)
18:30	_ato	could be worse though I guess
18:53	hiredman	http://scienceblogs.com/goodmath/2009/11/philosophizing_about_programmi.php
19:25	lusory	hi, does anybody know whether there are sample codes showing how to pack/unpack data from the network?
19:27	duncanm	hmm
19:28	duncanm	i just watched this techtalk on Google's new Go language, it's a bit underwhelming
19:30	froog	link?
19:31	duncanm	froog: it's on youtube
19:34	duncanm	aha, it's twbray
19:35	twbray	duncanm: G'day
19:36	duncanm	twbray: i was gonna leave a comment on your blog (or something); i saw your tweet about having functions with too many arguments from a few weeks ago, i think a judicious use of maps and structs will help with that
19:37	twbray	duncanm: Yeah, I eventually poured a bunch of somewhat-related things into a map and passed that around instead. Hey, if some of them were functions would that be O-O?
19:37	duncanm	twbray: yeah, it's a well-known technique used by Schemers
19:39	duncanm	twbray: the trade off is that dispatch is explicit (which is tedious to implement again and again), the plus side is that there's no distinction between functions and methods (usually just a symbol, ie in Smalltalk)
19:40	twbray	duncanm: Don't understand "dispatch is explicit"
19:41	duncanm	twbray: you have to remember to pull out the right method from the map when you call, and use it on the right data, on more traditional OO systems, you can't make that mistake
19:43	twbray	Right, the O-O flavor is not very strong.
19:51	duncanm	twbray: do you also write a lot of JRuby code?
19:52	duncanm	twbray: i really like that you can pass blocks in Ruby to make instances of interfaces (like java.io.FilenameFilter)
19:52	twbray	duncanm: Not really. I'm usually in MRI
19:52	twbray	Although the last piece of Ruby code I wrote ended up getting deployed in JRuby/GlassFish, which is not terribly rare these days
20:02	twbray	Damn... seem to be stubbing my toe on a nasty little bug. Is Clojure 1.0 very far out of date? Worth updating?
20:08	hiredman	twbray: have you seen map destructuring?
20:09	twbray	hiredman: nope
20:09	clojurebot	hiredman <3 XeLaTeX
20:09	hiredman	hmmmm
20:10	hiredman	hard to say, I usually use clojure from git, but the times I have used 1.0 I haven't hit any differences
20:10	hiredman	but my use of 1.0 is limited
20:11	twbray	I have a ref to a map that's refusing to deref when accessed in a sub-thread. Blecch. Works perfectly called from REPL.
20:11	hiredman	what do you mean refusing to deref?
20:12	twbray	I do (sort-by last > @unsorted) where @unsorted is a ref to a map and it works fine at top-level, when executed in a thread I get "java.lang.RuntimeException: java.lang.ClassCastException: clojure.lang.Ref cannot be cast to java.lang.Number"
20:13	hiredman	are you using agents at all?
20:13	twbray	Oh............. hold on. I'm a moron.
20:13	hiredman	I would suggest dropping a call to prn in there
20:13	hiredman	(the subthread)
20:14	twbray	D'oh, the map values are refs to numbers not numbers. The error message is perfectly correct and I'm a dork.
20:14	hiredman	if you are using agents at all it is very easy to accidently add layers of refs
20:14	hiredman	:P
20:14	hiredman	prn is your friend
20:33	burny	I'm giving a presentation on clojures to my university Programming Language Concepts class tomorrow. We've studied scheme, prolog, and javascript, most of the people are familiar with java and c++. Any suggestions on area's in particular to cover for a general overview of the language in about 15/20 minutes?
20:38	arbscht	clojurebot: rationale
20:38	clojurebot	rationale is http://clojure.org/rationale
20:38	hiredman	you might take a look at rich's "clojure for java programmers" and see what he covers
20:39	hiredman	clojurebot: blip.tv
20:39	clojurebot	blip.tv is http://clojure.blip.tv/
20:39	burny	yea, I've gone over it a couple times
20:39	burny	thanks
20:40	hiredman	there are a lot of little neat corners of the language
20:40	hiredman	callability as an interface anthing can implement
20:56	chouser	rhickey: will the next release be called 2.0, since we're now past Clojure's second year?
20:58	rhickey	chouser: good question, I don't think so
20:59	duncanm	hiredman: ah, that's a good point
20:59	twbray	HAH! Am now keeping 25+ on average of the 32 cores in a Niagara maxed processing the Wide Finder dataset.
21:00	rhickey	twbray: cool
21:01	twbray	Gonna have to get a JVM/Solaris guru to look at this puppy, swings wildly back & forth between high concurrency & occasional single-threadedness, I'm sure there are JVM options & so on to help.
21:02	durka42	garbage collection?
21:02	hiredman	~google headius jvm flags
21:02	clojurebot	First, out of 279 results is:
21:02	clojurebot	Headius: My Favorite Hotspot JVM Flags
21:02	clojurebot	http://blog.headius.com/2009/01/my-favorite-hotspot-jvm-flags.html
21:03	twbray	Yeah... currently java -d64 -Xmx18000m -XX:+UseParallelGC
21:06	rhickey	now with dates - http://pragmaticstudio.com/clojure
21:08	twbray	I suppose that a big clojure program is going to generate disposable java objects at a ferocious rate...
21:08	rhickey	twbray: yes, lots of ephemeral garbage
21:10	twbray	Interestingly, my program had the computer maxed until it hit its max heap (18G) and now the concurrency is varying between 1x and 8x, presumably because it's competing with gc all the time.
21:10	headius	twbray: you might want to try +UseConcMarkSweepGC
21:10	headius	it should help a bit
21:10	headius	parallelGC doesn't actually run concurrently
21:11	headius	it just stops the world for less time by using multiple threads to GC
21:11	headius	you must be generating a ton of garbage
21:11	headius	I don't know if that's typical for clojure ornot
21:11	twbray	Well, it's Wide Finder... it has a ref to an int for each URL (a few thousand of 'em) and it's updating them at many tens of thousands per second.
21:11	hiredman	I generate tons of garbage :P
21:12	twbray	Gosh.... does this mean that immutability isn't free?!? I'm shocked... shocked.
21:12	hiredman	that doesn't sound like it should generate garbage
21:12	twbray	Well, every time I do (ref-set some-int (inc @some-int)) the old value is now garbage. Right?
21:13	rhickey	hiredman: boxed numbers can yield a lot of garbage
21:13	hiredman	oh
21:13	hiredman	right
21:13	hiredman	twbray: (alter ref inc)
21:13	rhickey	yes, please
21:14	hiredman	,(doc alter)
21:14	clojurebot	"([ref fun & args]); Must be called in a transaction. Sets the in-transaction-value of ref to: (apply fun in-transaction-value-of-ref args) and returns the in-transaction-value of ref."
21:14	headius	rhickey: we need to get a pool together for fixnums in mlvm
21:14	rhickey	headius: I think it's the #1 problem for dynamic langs on the JVM
21:15	rhickey	perf-wise
21:15	headius	probably...and #2 would be lack of closure-conversion during inlining
21:15	headius	if we had both of those I'd have far fewer headaches
21:15	twbray	Why would alter generate less garbage?
21:15	rhickey	twbray: it doesn't, just more idiomatic
21:16	hiredman	twbray: I dunno that it would, but alter is prefered to ref-set
21:16	twbray	Crap... 30 minutes into the run, it's now single-threaded :(
21:16	twbray	OK, gc research after dinner.
21:16	headius	twbray: log some GC stuff to see if that's the problem
21:16	hiredman	you might be ok with commute instead of alter, but I always get confused so I stick to alter
21:17	headius	it shouldn't impact you that much
21:17	clojurebot	much is permittted
21:17	headius	-XX:+PrintGCDetails
21:17	headius	if you see incremental GC runs streaming by, or lots of full GCs, you'll know it's an issue
21:17	twbray	headius: will do
21:18	duncanm	oh, this is fun
21:18	duncanm	twbray: you're gonna write a blogpost on this debugging session, right? ;-)
21:19	twbray	Oh yeah. Lotsa fodder here. But I want some good numbers.
21:20	twbray	As in "dramatically faster than the equivalent perl code on a multi-core machine"
21:20	duncanm	twbray: the perl code isn't using the multi-core at all, is it?
21:20	chouser	headius: what's closure-conversion during inlingin?
21:20	twbray	"equivalent single-threaded perl code" I mean
21:20	duncanm	ah
21:22	headius	chouser: current JVMs will not inline closures all the way back to where they're instantiated, since the method they're passed to ends up being megamorphic
21:22	headius	a ruby example: [1,2,3].each {\|x\| ...}
21:22	chouser	megamorphic means types with perhaps the same method name but no parent class in common with that method name?
21:23	headius	you'd like "each" and the closure to inline into the caller, but they can't because each gets used for lots of different call paths
21:23	chouser	ah
21:23	headius	megamorphic means they're all of some "closure" type, but there's many different ones
21:23	headius	unless each only ever receives one closure, it won't inline it
21:24	headius	that means you can't get most inlining optimizations whenever there's an intermediate call like "each"
21:26	headius	jrockit guys said it wouldn't be hard to add, but it's not in any current JVMs
21:29	headius	rhickey: more frustrating to me than lack of fixnum support is that the majority of comparison benchmarks on the interwebs are numeric-heavy...so we end up looking sucky
21:31	rhickey_	headius: exactly, the most trivial things look the worst, too
21:32	headius	yes
21:32	headius	stupid fi
21:32	headius	fib
21:32	duncanm	heh
21:32	headius	if I had time for more projects I might work with maxine guys to hack fixnums in
21:33	duncanm	oh, i read about maxine, it looks pretty cool
21:33	duncanm	headius: do you know what the status is for interface injection?
21:33	headius	duncanm: fading quickly...no resources to work on it
21:33	headius	at this point I think I might like fixnums more
21:33	headius	but I want it all
21:33	duncanm	oh, that's too bad, that's one feature that I find very exciting
21:34	headius	I find then all exciting
21:34	headius	I wish I knew hotspot better to help out :)
21:34	headius	bbl
22:45	qed	oh man im excited for RubyConf
22:45	qed	S. Halloway has a talk about Clojure
22:45	wooby	will the vids be up somewhere?
22:46	qed	yeah eventually
22:47	qed	actually they will likely be up the same day
22:47	wooby	awesome
22:48	qed	i hope clojure sticks around for awhile
22:48	JAS415	oh jeeze
22:48	JAS415	me too
22:48	qed	ive really grown to love it, except for the whole JVM thing
22:48	qed	;)
22:48	qed	i mean, if i was a java programmer in the first instance, i would be loving clojure
22:49	qed	but for me this is more like my first foray into java
22:49	qed	ive avoided it for such a long time
22:49	qed	i wrote some long long ago in a far away place
22:49	wooby	qed: what did you work in primarily?
22:50	qed	wooby: C++ at first, then I got turned on to perl, then to ruby, ruby has lasted me awhile, then i found clojure
22:50	qed	well actually i found a lot of languages in between ruby and clojure
22:50	qed	but clojure is the only one i thought to be worth learning
22:51	qed	i played with haskell for awhile, got bored
22:51	qed	clojure has kept me interested
22:51	wooby	yeah i tinkered with haskell also
22:51	qed	i think most of us did
22:52	qed	clojure is where the haskell rejects go
22:52	qed	:X lol
22:52	wooby	followed the java -> ruby -> scala trajectory and settled on clojure finally, love it... feels like i won't want or need to learn anything else for a long time
22:52	chouser	where would clojure go if it doesn't stick around for awhile?
22:52	qed	chouser: i didnt mean anything by that
22:52	chouser	oh, ok.
22:53	qed	i guess what im saying is that im praying for a long and healthy prosperous language
22:53	chouser	:-)
22:53	qed	i really enjoy clojure and cant wait to see the things people will inevitably build for it
22:53	wooby	i cant wait to see more clojure jobs ;)
22:53	qed	oh man
22:53	qed	if i could get a job writing clojure...
22:54	wooby	i know
22:54	qed	the world would likely explode
22:54	wooby	that's the ultimate
22:54	qed	that's like LAMBDA
22:54	wooby	second only to being paid to work on my own toy languages lol
22:54	qed	haha
22:54	qed	hey now -- clojure aint just a toy anymore
22:54	qed	or at least i dont see it that way
22:54	qed	it's maturing pretty rapidly
22:54	wooby	i know but my stuff is ;)
22:55	qed	chouser: what do you see the 5 year outlook for clojure being?
22:55	qed	chouser: nothing too serious, just sort of your wishes and hopes
22:57	chouser	a variety of hosts besides JVM -- iphone, jvm, clr, javascript, chickenscheme, maybe C++
22:57	qed	i didnt even consider that
22:58	qed	what is clr chouser ? ive heard that term passed around a lot.
22:58	wooby	it's like microsoft's jvm
22:58	chouser	qed: that's the C# runtime
22:58	qed	ahhh
22:58	qed	what about ruby?
22:58	qed	:X
22:58	_ato	parrot
22:58	qed	is that heresy?
22:58	wooby	chouser: have you looked at nu?
22:58	chouser	yes, parrot
22:58	chouser	wooby: I don't think so
22:59	qed	the iphone would be really interesting
22:59	chouser	someone will have solved the dependency problem well, so you'll declare your deps, and someone can install with a single command that also fetches and installs the dpes.
22:59	wooby	chouser: http://programming.nu/
22:59	qed	chouser: fwiw i appreciate so much the work youve done on clojure
23:00	qed	its not said enough
23:00	qed	thank you
23:00	chouser	heh. well, thanks. I do hardly anything.
23:00	chouser	rhickey is the workhorse
23:00	qed	you're part of the machine, and you being in here right now answering my questions as you've done for the past month or so
23:00	qed	has not gone unnoticed
23:01	qed	so thanks :)
23:01	qed	chouser: is there any active documentation project going on?
23:02	qed	one thing i miss is a really complete set of documentation that includes code samples
23:03	chouser	wooby: No, I haven't looked at nu before.
23:03	st3fan	nu is interesting
23:03	devlinsf	@qed It's a work in progress
23:03	wooby	chouser: it's probably only worth a look if you're into obj-c/cocoa at all, but i've found it a really nice way to build things for macs
23:03	wooby	chouser: and the runtime definitely pays the way for clojure-on-cocoa :)
23:03	wooby	*paves
23:04	chouser	qed: there are a few efforts related to docs going on. That'll be solved in the next 5 years too. :-)
23:04	devlinsf	@qed There is some effort going on trying to improve the documentation for contrib. Tom F. is doing a lot to create refernce documentation
23:06	danlarkin	s/someone/technomancy :-D
23:09	technomancy	danlarkin: ssshhh! I'm not _quite_ ready yet. =)
23:09	burny	Any suggestions for my presentation? http://docs.google.com/present/edit?id=0AZJoMk7c8j5uYXd6NWNoY3hjbm1fNjJrazV0N2Jodg&hl=en
23:10	wooby	burny: looks awesome, sp on pg 3: "Functinonal Languaguage"
23:10	wooby	reading though
23:10	chouser	wooby: yeah, any lisp-like syntax with macros is a win, even if it's a thin layer over a host language
23:11	_ato	burny: slide 5 s/Full/Fully/
23:12	burny	_ato: wooby: haha oops! thanks
23:13	wooby	burny: is it for school?
23:14	burny	wooby: yea, Programming Languages course
23:14	durka42	if we're into spelling, Breif on slide 2
23:15	wooby	burny: i like the compojure/incanter examples, cool way to show the power
23:16	_ato	burny: I'd say something about how the mind-blowing persistent hash maps and vectors are immutable yet still fast and memory efficent (due to state sharing), but it depends on the audience :)
23:17	burny	_ato: I'm gonna do a run through, if I have some time I'll be sure to add it in, thanks.
23:17	chouser	burny: should use (doseq ...) instead of (dorun (for ...)) unless you're specifically trying to show 'for'
23:19	burny	chouser: Thanks, I didn't know that
23:19	devlinsf	chouser: got a minute to talk about c.c.map-utils?
23:20	wooby	burny: do you go to RIT by any chance?
23:20	qed	technomancy: now i know why you got turned down for your rubyconf proposal
23:20	qed	what with stuart H. getting his clojure presentation accepted and all
23:22	chouser	devlinsf: hm, my name is in that file, isn't it.
23:22	chouser	I wonder why
23:22	timothypratley	stupid question, I'm formatting a patch and have gone blank on how to run the tests
23:22	chouser	ah, deep-merge-with.
23:22	technomancy	qed: yeah, but my talk was actually related to ruby. =\
23:22	devlinsf	chouser: deep-merge-with
23:22	chouser	devlinsf: what's up?
23:23	chouser	timothypratley: for clojure itself? ant jar test
23:23	timothypratley	thanks!
23:23	devlinsf	chouser: I've had a post about two libs on the dev list, c.ctable-utils & c.c.map-utils. I think the table-utils lib needs a little more time, but the map-utils is ready to go
23:24	devlinsf	chouser: do I need Rich's approval for a patch?
23:24	chouser	devlinsf: not for contrib, no.
23:25	devlinsf	chouser: okay, so an assembla ticket w/ docs, test & code could get applied. Who would do the actual application?
23:25	chouser	devlinsf: I see your posts. I had forgotten I was responsible for map-utils. I'll take a look at some point.
23:26	devlinsf	chosuer: thanks
23:27	timothypratley	BUILD FAILED Target "test" does not exist in the project "clojure". <--- should I be worried?
23:28	timothypratley	arrrrghhhh!!!! ignore me, I was in a really old snapshot directory for some reason
23:29	timothypratley	slinks away
23:35	JAS415	does anyone use clojure from a VPS?
23:37	JAS415	nvm found something about it through google :-)
23:47	burny	wooby: yes I do
23:49	wooby	me too
23:50	burny	very cool
23:50	burny	se/ce/cs/one of the other hundreds of computing majors?