#clojure – 2009-04-06

2009-04-06

01:48	jsankey	(java.io.File. "a\\b")
01:49	jsankey	,(java.io.File. "a\\b")
01:49	clojurebot	#<File a\b>
01:50	jsankey	,(.parentFile (java.io.File. "a\\b"))
01:50	clojurebot	java.lang.IllegalArgumentException: No matching field found: parentFile for class java.io.File
04:43	kefka	I've noticed that ArrayList access seems to be slow in a Clojure REPL. Am I doing something wrong?
04:44	AWizzArd	more info please
04:44	AWizzArd	you are using the default JVM methods, so it should not be any slower
04:44	kefka	,(time (let [a (new ArrayList (range 10))] (doall (for [i (range 100000)] (.get a 5)))))
04:44	clojurebot	java.lang.IllegalArgumentException: Unable to resolve classname: ArrayList
04:44	kefka	,(time (let [a (new java.util.ArrayList (range 10))] (doall (for [i (range 100000)] (.get a 5)))))
04:45	kefka	It takes about 1.3 microseconds per access on my machine.
04:45	cconstantine	I've got a crazy idea; Would it make sense to read files as a lazy-seq? Each element in the sequence would be an item from the file (Something like a line, or other defined chunk). This would make reading a file in a (dosync ...) easy/fast and would allow you to use all the nice drop, drop-while, filter, etc. lazy-seq functions. Am I crazy?
04:46	kefka	I'm on a 2.6 GHz machine, so this is thousands of clock cycles
04:46	kefka	per .get
04:47	kefka	,(time (let [a (new java.util.ArrayList (range 10))] (dorun (for [i (range 100000)] (.get a 5)))))
04:47	kefka	dorun, not doall... I think my doall might have hurt the Clojurebot
04:47	cconstantine	kefka: that returns a long list
04:47	kefka	,(+ 3 4)
04:48	kefka	Yes, I should have been using dorun. dorun doesn't return.
04:48	Cark	,(doc line-seq)
04:48	kefka	doall returns a huge seq
04:48	Cark	did you guys kill poor clojurebot ?
04:48	kefka	Clojurebot seems to have been killed by my huge doall. Sorry. :(
04:48	kefka	How does one get it back?
04:48	cconstantine	I get "Elapsed time: 66.048 msecs"
04:49	cconstantine	talk to hiredguy?
04:49	Cark	anyways constantine : have a look to line-seq
04:50	kefka	cconstantine: It takes me about 100 msec, but that seems a lot longer than it should be, for 100k ArrayList accesses.
04:50	kefka	On a 2.6 GHz machine, that's 2600 clock cycles per access
04:50	cconstantine	Cark: that is pretty close to what I was thinking of :)
04:51	Cark	yes though i'm not sure the file gets closed if you never go to the end of it
04:51	Cark	at least it should be upon GC
04:51	cconstantine	Cark: right, it would have to be wrapped in either a generator func or macro
04:51	cconstantine	for the file open/close
04:52	Cark	i don't know ... i think rhickey was working on something for this ...
04:52	cconstantine	kefka: no idea what's up.... I've had disapointing results timing simple counting loops (last (range 1 100000)) compared to C
04:53	Cark	you're not comparing the same thing
04:53	Cark	use loop/recur
04:53	cconstantine	I got similar timings with loop/recur
04:53	Cark	on server jvm
04:53	cconstantine	yup
04:53	Cark	did you take "warm up " into account ?
04:54	cconstantine	I'm inclined to think clojure isn't 100 times slower than C, and that I'm doing it wrong
04:54	Cark	and used unsafe maths ?
04:54	cconstantine	unsafe maths (unchecked-inc ...) didn't seem to effect speed
04:54	Chousuke	did you make sure there is no reflection?
04:54	Cark	you coerced the counter to integers ?
04:55	cconstantine	no reflection?
04:55	cconstantine	I started with raw numbers at the reader, and used unchecked-inc
04:56	Chousuke	well, (.get foo 5) would cause reflection without a type hint.
04:56	Chousuke	bind warn-on-reflection to true :/
04:56	cconstantine	ah, and the time-to-run was linear with the number of increments, so the there was no "warm-up" factor
04:56	cconstantine	ah, I've done that. I wasn't getting reflection
04:57	cconstantine	poor clojurebot
04:58	cconstantine	I dunno, the only reason I cared even a little was that a friend doing project clojure was getting answers 10/100 times faster in C than I was in clojure using the same basic algorithms
04:58	cconstantine	I'm not too worried; another friend is using haskell and getting similar timings to me
04:59	cconstantine	s/project clojure/project euler/
05:00	cconstantine	and our runtimes are on the order of 1-5 seconds
05:01	gnuvince	For simple problems like that, Clojure doesn't have much of a problem with performance.
05:02	cconstantine	it's ok, I beat him on code simplicity, code length, and generality of solution (his won't work for N too large)
05:03	gnuvince	He's probably not using Integer
05:04	cconstantine	He's using C, so his types are like 'int'
05:04	Cark	hum testing this i just discovered that i can't run the server jvm on my 64bit computer =/
05:04	gnuvince	cconstantine: oh, I thought he was using Haskell
05:05	cconstantine	gnuvince: ah, yes the haskell guy is using Integer
05:09	Cark	i have a deamatic increase in speed when using server jvm, and running the test several times
05:09	Cark	dramatic
05:09	Cark	lisppaste8: url?
05:09	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
05:10	lisppaste8	cark pasted "untitled" at http://paste.lisp.org/display/78102
05:13	hiredman	~ticker JAVA
05:13	clojurebot	No entiendo
05:13	hiredman	useless
05:14	AWizzArd	,(doc for)
05:14	clojurebot	"([seq-exprs body-expr]); List comprehension. Takes a vector of one or more binding-form/collection-expr pairs, each followed by zero or more modifiers, and yields a lazy sequence of evaluations of expr. Collections are iterated in a nested fashion, rightmost fastest, and nested coll-exprs can refer to bindings created in prior binding-forms. Supported modifiers are: :let [binding-form expr ...], :while test, :when test. (take 100 (for [x (range 100000
05:15	AWizzArd	kefka: You use dorun and not dotimes?
05:16	AWizzArd	On my machine your (time (let [a (new java.util.ArrayList (range 10))] (dorun (for [i (range 100000)] (.get a 5))))) ==> "Elapsed time: 55.393632 msecs"
05:16	AWizzArd	kefka: but (time (let [a (new java.util.ArrayList (range 10))] (dotimes [i 100000] (.get a 5)))) ==> "Elapsed time: 7.141131 msecs"
05:17	AWizzArd	'(/ 100000 7.141131)
05:17	AWizzArd	,(/ 100000 7.141131)
05:17	clojurebot	14003.384057791407
05:17	AWizzArd	14000 reads per millisecond
05:17	jgracin	Hi! Could someone please help me resolving a "not releasing the head" problem. I'll paste it in a sec.
05:17	lisppaste8	jgracin pasted "Out of heap space" at http://paste.lisp.org/display/78104
05:17	AWizzArd	No wait, nonsense of course. That is lazy and was not run.
05:19	Cark	i think it gets optimized out
05:21	jgracin	is it because "lines" is a parameter which stays bound until the function exits? I guess that's it, isn't it?
05:22	mihand	hey guys! is (int (/ a b)) the idiomatic way to do truncating division ?
05:22	Chouser	mihand: quot
05:24	Cark	jgracin : when you call find-save-debug the lines parameter points to the head of the lines sequence
05:24	Cark	so you're retaining the head
05:25	jgracin	Cark: thanks! Is there any way I can deal with this? Is this what streams are for? Where are the streams?
05:26	Cark	you could change entire-log-line-seq to return a function that will return the sequence
05:26	Chouser	streams are experimental, not in trunk
05:26	Cark	and pass that as a parameter to find-saved-debug
05:26	Cark	hey hello chouser
05:27	Raynes	Hey hello hi Chouser.
05:27	Raynes	Cark: I win.
05:27	Chouser	hi guys
05:27	cemerick	hey, Chouser's back, all's right with the world again! :-D
05:27	jgracin	So I can't pass infinite lazy sequences into functions because that will necessarily blow up the heap.
05:28	jgracin	I mean, if they decide to make a long search through the seq.
05:28	lisppaste8	cark annotated #78104 "untitled" at http://paste.lisp.org/display/78104#1
05:28	Chouser	hm, that can't be quite right, since you can pass infinite lazy seqs to 'filter' without a problem.
05:28	Cark	try this untested change
05:28	Cark	chouser : filter probably uses recur
05:29	Chouser	no, it's lazy. uses lazy-seq
05:29	Cark	~def filter
05:29	Cark	well then it returns immediately
05:29	jgracin	my entire-log-lines-seq uses concat which I counted on using lazy-seq internally.
05:31	Chouser	that should be ok (though mapcat would be more succinct)
05:32	Cark	jgracin : try my solution and tell us how it goes !
05:35	jgracin	Cark: yup, it works. Thanks! I do understand how and why. It's just that it doesn't seem quite elegant. Does the streams address this kind of problem or are they for different purposes?
05:35	Cark	yes they do
05:35	Cark	hum there is another way
05:35	Cark	you could build your own filtered lazy sequence
05:35	Cark	~def filter
05:36	Chouser	are locals cleared out before tail calls?
05:38	lisppaste8	cark annotated #78104 "untitled" at http://paste.lisp.org/display/78104#2
05:39	Cark	not sure if that will do it
05:41	Cark	chouser : my guess would be that the pointers are overwritten
05:41	Cark	so no more reference, so garbage collectable
05:48	Chouser	yes, that appears to be the case. if so, then just moving the call to 'first' out of find-saved-debug might do it
05:48	Chouser	oh
05:48	Chouser	like Cark's second annotation.
05:48	Chouser	:-)
05:48	Cark	=)
05:49	jgracin	thanks!
05:49	Chouser	except saved-debugs is still a fn that needs to be called with the right args, but that's the gist I was headed for.
05:49	Chouser	oh, nm.
06:06	Mec	is there an opposite of slurp that writes a string to a file?
06:07	dliebke	,(doc clojure.contrib.duck-streams/spit)
06:07	clojurebot	java.lang.Exception: Unable to resolve var: clojure.contrib.duck-streams/spit in this context
06:08	dliebke	clojure.contrib.duck-streams/spit writes a string to a file
06:09	Mec	thanks
06:10	Mec	hmm class not found exception
06:10	Cark	,(use 'clojure.contrib.duck-streams)
06:10	clojurebot	java.io.FileNotFoundException: Could not locate clojure/contrib/duck_streams__init.class or clojure/contrib/duck_streams.clj on classpath:
06:10	Cark	works on my machine !
06:11	Mec	yup i got it now
06:11	Mec	will spit overwrite the file?
06:13	dliebke	yes, it appears to overwrite the file
06:14	Mec	excellent, thanks
06:24	hiredman	~ticker JAVA
06:24	clojurebot	Pardon?
06:24	hiredman	clojurebot: are you for real?
06:24	clojurebot	for is not a loop
06:26	cconstantine	ok, so it turns out I'm not using a java server
06:26	cconstantine	is there a place that talks about how to do that?
06:28	cconstantine	nm, I needed to ask the question for me to answer it myself
06:31	hiredman	~ticker JAVA
06:31	clojurebot	JAVA; -1.98
06:38	cemerick	is it true that there's no way to determine how many arguments a fn can accept?
06:39	Chouser	you can call it with n args, and if you get an exception then it doesn't except that many.
06:39	Chouser	or of those types.
06:39	Chouser	or something else is wrong.
06:39	hiredman	cemerick: it is true
06:39	cemerick	so if I pull a fish out of a random hole, I get to keep the fish? ;-)
06:40	Chouser	you can look at the :arglists metadata of a var
06:40	Chouser	but that can be overwritten by the user, so ... shrug
06:40	hiredman	Chouser is trying to sugar coat it for you
06:41	Chouser	you can do what the 'source' macro does to find the clojure source for the fn, use 'read' and 'macroexpand' and analyze the results...
06:42	cemerick	I think I'd just make a macro that attaches arity metadata :-)
06:43	cemerick	but wow, dropping to the source macro is imaginative...
06:43	Chouser	but so very very wrong
06:44	hiredman	Fn objects don't let you attach metadata
06:44	cemerick	ah, damn
06:44	hiredman	Yeah
06:44	Chouser	well, they don't let you change metadata. You can use proxy to provide unalterable metadata when you creating the instance.
06:45	hiredman	well, I guess there is that
06:45	Chouser	which actually sounds about perfect for arity
06:46	cemerick	ah, AFn has metadata. I'd think IFn would extend IObj.
06:46	Chouser	what would this metadata look like? a set of the accepted arities?
06:46	Chouser	but then what about variadics?
06:46	cemerick	I'm not sure yet. We need a little more than just arity (type info, aaack!), but it'd always be immutable.
06:47	cemerick	I don't think we have any variadic fns in this particular corner of things.
06:48	cemerick	eh, maybe we should just pass around maps with a :fn key where the actual function lives. I'll bet we'll want to assoc some amount of stuff into a fn's 'metadata' eventually.
07:17	Chouser	recur is a bit of a problem
07:18	Chouser	it refers to it's own kind of scope -- not dynamic, not lexical of the sort that can be closed over.
07:21	cemerick	that's the tradeoff for constant-space stack usage, right? The "real" solution is TCO or trampolining.
07:23	Chouser	It seems it might be theoretically possible to recur to a named loop in your lexical scope...
07:23	Chouser	hm, maybe not -- if you close over that name, then call the closure from outside that lexical scope, where does the recur go?
07:23	cemerick	oh, so you could choose to recur to the next loop up, or optionally to an outer loop or the fn you're in?
07:24	cmvkk	what are you trying to do?
07:24	Chouser	cemerick: yeah, that's what I was thinking, but I specifically wanted to be able to close over that name, so that I could 'recur' to a named loop instead of having to recurse to a named fn.
07:25	Chouser	cmvkk: fix error-kit
07:25	Chouser	ugh, sounds like I might be asking for continuations without knowing it.
07:25	cemerick	you inch towards a reified environment at that point, I think.
07:25	cemerick	indeed
07:26	cemerick	that's not entirely horrible in the scope of error-kit, though, right?
07:27	Chouser	what's not horrible, continuations?
07:28	cemerick	within the scope of using error-kit facilities, requiring people to work with a separate, reified environment
07:28	cemerick	penalty there, certainly
07:29	Cark	i'm trying to use clojure.contrib.pprint/pprint it works ok in the repl, but i can't seem to make it work from an executable jar file, any idea on how i could make it work ?
07:29	Chouser	oh, I see. But building that kind of reified env is more than I'd like to do. So far I've avoided any real code-walking.
07:30	Chouser	my problem is that the body of a 'handle' form is a closure, so that it can use names from the 'with-handler' scope. But since the handler can do 'continue-with' which requires it be executed in the dynamic and call-stack scope of the 'raise'
07:31	Chouser	that's all fine until someone tries to 'recur' from inside a 'handle' form, excepting it to jump back to a 'loop' outside of the 'with-handler'
07:31	cemerick	ah, I get it
07:31	cemerick	well, how does CL do it in the face of goto?
07:32	Chouser	no idea. But since it has neither 'continue-with' (as far as I can tell) nor 'recur', it may just not have that problem.
07:33	cemerick	well, recur is just a special case of goto
07:34	cemerick	continue-with (if I understand the semantics) is the trickier problem, it seems. That's a big jump from an error providing a set of fixed restart options.
07:35	cemerick	Cark: what error/problem are you seeing?
07:35	Cark	nothing, it just does not output a thing
07:35	Chouser	I already toss bits of extra data up the call stack -- I suppose I could provide a 'kit/recur' that causes the recur to happen at the right scope.
07:36	Chouser	I could even code-walk and try to replace 'recur' with 'kit/recur' where appropriate
07:36	cmvkk	that seems like the only option, if you're trying to remove a point of recurrance
07:38	Chouser	but I'm sure it's another strike against ever getting this into core (if there was any chance left anyway)
07:38	cmvkk	would it be possible for a no-recurring-fn special form to exist, out of curiosity?
07:38	cmvkk	an fn that doesn't affect recur, i mean
07:39	cemerick	Cark: I'm afraid I've never used it myself. In general, it sounds like out isn't being bound properly, or something similar.
07:40	cemerick	Chouser: seems like two separate issues: implementing delimited continuations, and secondly building error-kit on top of them
07:40	Cark	could be that, thanks cemerick
07:43	cgrand	Chouser: mutable state + ugly macroing can help you intercept a recur without code walking
07:44	cgrand	hmmm, no it won't work without knowing the number of args to recur which require code walking :-(
07:45	cemerick	hrm, more ammo for my decorate-fns-with-arity-info suggestion ;-)
07:46	Drakeson	how can I memoize a lazy Var? imagine (def fibs (lazy-cat (list 1 2) (map + fibs (drop 1 fibs))))
07:47	Chouser	cgrand: how would I prevent 'recur' from just doing it's normal special-form thing? no macro or fn is going to get in the way, is it?
07:48	cgrand	I was thinking of introducing a... hmm wait, must check something
07:53	Cark	cemerick : output wasn't flushed before my program exited
07:53	Cark	thanks
07:53	cemerick	Cark: ah-ha! :-)
07:53	cemerick	heh, I didn't no anything
07:56	lisppaste8	cgrand pasted "bad idea" at http://paste.lisp.org/display/78118
07:57	kotarak	hiredman: a problem?
07:57	Chouser	ah! very nice.
07:58	Chouser	cgrand: where "nice" == "twisted and evil"
08:01	Chouser	cgrand: did you try using a variadic fn instead of loop?
08:02	Chouser	doesn't work, because recur wants you to pass the variadic part as a seq
08:04	Chouser	huh, you can't 'recur' from a catch or finally either. maybe not supporting 'recur' in a 'handle' isn't so bad.
08:06	triddell	Does anyone know of a change (in the last month or so) which would cause "Wrong number of args passed" error on gen-classed code that was working just fine before?
08:08	triddell	From Java I'm calling a function which then calls another Clojure function and I get this error now. The method which is called from Java includes "this" are the first argument but the inner call doesn't (and didn't need to before.)
08:10	triddell	Probably doesn't make much sense, but I'm calling a function with four arguments (which takes four arguments) and now I'm getting this error.
08:15	lisppaste8	slashus2 pasted "stm test" at http://paste.lisp.org/display/78119
08:15	slashus3	Why doesn't await-for stop the agents after the timeout in this case?
08:16	slashus3	oh... wait, I need to add print-agt to the await-for
08:17	slashus3	I don't think that worked either.
08:17	slashus3	And I am curious to why the print agent isn't printing anything.
08:18	slashus3	Beware. Be sure to kill this process asap, it will eat up your memory.
08:19	cmvkk	well nothing gets sent to print-agt until after the other agents have finished
08:20	slashus3	cmvkk: Why don't they timeout?
08:20	cmvkk	anyway, when i run that it returns for me
08:21	slashus3	Does it return false?
08:21	cmvkk	yes.
08:21	cmvkk	after about 5 seconds, as expected.
08:21	slashus3	You better kill the process. They are still running.
08:21	cmvkk	yeah. they are.
08:21	slashus3	It will return nil if it returned because of a timeout, but it returns false?
08:22	cmvkk	yeah that's weird, because it's supposed to be nil or non-nil.
08:22	slashus3	right
08:22	cmvkk	but if you wanted to test against it, why would you return false?
08:22	cmvkk	and being able to test against it is the point of returning nil or non-nil
08:23	slashus3	I would think that it should kill all of the agents after the timout, but it just kills my computer slowly after returning.
08:23	slashus3	That is why I am using await-for there.
08:24	slashus3	I wanted it to print out the results of the two agents for 5 seconds and stop.
08:24	cmvkk	it's an infinite loop, and all it does is sen-off and commute.
08:24	cmvkk	assuming those things are waiting until after the original fn returns
08:24	cmvkk	then they just build up a huge queue, then when await-for stops them, they do all the send-offs at once?
08:24	cmvkk	maybe?
08:25	slashus3	Well with each transaction, I would think there should be a send-off.
08:25	slashus3	I would think that those prints would be interleaved with the other agents.
08:25	slashus3	I know it is bad practice, but even if you use (println) it won't kill them after 5 seconds.
08:29	slashus3	If await-for doesn't work in this case, how would you handle this situation?
08:31	slashus3	:-(
08:34	slashus3	There is no way to control agents with infinite loops?
08:34	kotarak	slashus3: you have to probably rewrite them to send to themselves.
08:35	slashus3	kotarak: I guess that is the solution. await-for won't stop agents that have infinite loops.
08:36	kotarak	I think await only waits for them to finish. But maybe I'm mistaken...
08:36	kotarak	(doc await-for)
08:36	clojurebot	Blocks the current thread until all actions dispatched thus far (from this thread or agent) to the agents have occurred, or the timeout (in milliseconds) has elapsed. Returns nil if returning due to timeout, non-nil otherwise.; arglists ([timeout-ms & agents])
08:36	slashus3	apparently it returns false if the agent is still going after the timeout.
08:43	lisppaste8	slashus2 annotated #78119 "stm test again" at http://paste.lisp.org/display/78119#1
08:43	slashus3	kotarak: This still doesn't stop when await-for is called.
08:44	kotarak	slashus3: I don't think, that await-for stops something.
08:46	kotarak	You'll have to use some flag: (send agent (fn this-fn [_] (when @running (send agent this-fn)))), when you want to stop the agent loop, you have to do a (reset! running false) (assuming that running is an atom)
08:46	Lau_of_DK	Good evening all
08:46	kotarak	Hi Lau
09:09	cgrand	Chouser: varidic support in recur was what I checked just before pasting :-)
09:22	twansit	Hello all!
09:22	Lau_of_DK	Yo dude
09:22	twansit	question what is the most effecient way to turn a json object to a clojure object with the keys as keywords?
09:23	twansit	or is it just not advisable
09:23	danlarkin	(json/decode-from-str string) of course!
09:23	twansit	ah..is that in clojure-contrib?
09:24	danlarkin	there is a json lib in contrib yes, but there's also clojure-json
09:24	twansit	yeah the contrib version doesn't do this
09:25	kotarak	o.O sheesh I really got out of sync with contrib...
09:25	twansit	danlarkin : i see you are plugging yourself :)
09:25	danlarkin	somebody's gotta :)
09:27	hiredman	~google clojure-json
09:27	clojurebot	First, out of 1880 results is:
09:27	clojurebot	danlarkin's clojure-json at master - GitHub
09:27	clojurebot	http://github.com/danlarkin/clojure-json/tree/master
09:27	twansit	gittin
09:27	twansit	gittin' it
09:28	kotarak	hiredman: why do you hit my poor vc?
09:28	hiredman	clojurebot uses clojure-json for google search results
09:28	hiredman	kotarak: I retract my hitting
09:29	kotarak	hiredman: oh ok, thought there was a problem ...
09:30	hiredman	I am getting weird indentation, but it is on a scrap file, so maybe I have a unbalanced paran somewhere
09:30	kotarak	ok, hopefully. There are some corner cases. But they should happen rarely.
09:31	twansit	danlarkin: thanks!
09:33	danlarkin	twansit: my pleasure
09:38	erohtar_	is there a way to pass a dynamically constructed vector to the binding form?
09:39	kotarak	erohtar_: (try (clojure.lang.Var/pushThreadBindings {varA valA varB valB}) ..... (finally (clojure.lang.Var/popThreadBindings)))
09:52	pjstadig	clojurebot: what is our mascot?
09:52	clojurebot	the official mascot of clojure is a futuristic ninja robot
09:54	Lau_of_DK	pjstadig, I was under the impression that danlarkin was our mascot?
09:54	danlarkin	oh jeez
09:55	pjstadig	Lau_of_DK: danlarkin is a futuristic ninja robot??!!!
09:55	opqdonut	wow!
09:55	Chouser	that's so much better than any of the historical ninja robots
09:55	Lau_of_DK	Thats certainly true
09:56	pjstadig	historical ninja robots are so 1999
09:56	Lau_of_DK	~at least the were so 1999, when suddenly...
09:56	clojurebot	CLABANGO!
09:56	pjstadig	clojurebot: historical ninja robots is <reply>historical ninja robots are so 1999...
09:56	clojurebot	In Ordnung
09:56	pjstadig	~historical ninja robots
09:56	clojurebot	historical ninja robots are so 1999...
09:57	pjstadig	clojurebot: futuristic ninja robots is <reply>sooo much better than historical ninja robots
09:57	clojurebot	c'est bon!
09:57	pjstadig	~futuristic ninja robots
09:57	clojurebot	sooo much better than historical ninja robots
09:58	pjstadig	hiredman: these are facts that should have been programmed into clojurebot from the beginning....I'm astonished!
09:59	erohtar__	kotarak: sorry - having network problems today
11:08	taggart	Can anyone see where I'm ging wrong with this port of an SICP example?
11:08	taggart	(def fibs (lazy-seq (cons 0 (cons 1 (map + (next fibs) fibs)))))
11:09	taggart	getting a stack overflow so it's not as lazy as I had hoped
11:12	Chouser	the problem is that cons is not itself lazy
11:13	Chouser	so as soon as you try to take one value from fibs, it computes 0 and 1 and (map ...)
11:13	taggart	I thought that was dealt with by the lazy-seq
11:13	Chouser	lazy-seq only makes one level lazy
11:13	taggart	ahh
11:14	Chouser	without it, you'd get the overflow as soon as you def, instead of only after you try to take something from it
11:14	taggart	map is lazy though, so wouldn't I just the 0 and 1 be resolved immediately?
11:15	Chouser	map is lazy, but cons is not. the second cons forces map to do one step
11:16	taggart	ah, and then the cycle starts
11:16	taggart	got it, thx
11:16	Chouser	...which in turn forces fibs itself, which does the cons's, ... right.
11:16	Chouser	so find the one expression that you need to delay, and put lazy-seq around that instead.
11:17	taggart	(def fibs (lazy-seq (cons 0 (lazy-seq (cons 1 (lazy-seq (map + (next fibs) fibs)))))))
11:17	Chouser	I keep forgetting to try a more Socratic method.
11:17	kotarak	Why so many lazy-seqs?
11:17	taggart	I guess I really only need one around map?
11:18	Chouser	"so where would you put lazy-seq to avoid the recursion?"
11:18	Chouser	"what is the value of delaying the evaluation of the constants 0 and 1?"
11:18	Chouser	:-)
11:18	taggart	nada
11:19	taggart	(def fibs (cons 0 (cons 1 (lazy-seq (map + (next fibs) fibs)))))
11:19	taggart	woot
11:19	opqdonut	:)
11:21	Chouser	How would the 'fibs' definition look if it were written by scgilardi and put in clojure.contrib.lazy-seqs?
11:22	pjstadig	what is the air speed of a swallo?
11:22	pjstadig	*swallow
11:22	Chouser	~google what is the air speed of a swallow?
11:22	clojurebot	First, out of 227000 results is:
11:22	clojurebot	What is the air-speed velocity of an unladen swallow
11:22	clojurebot	http://indianajones.arystoteles.pl/swallow.htm
11:43	lisppaste8	slashus2 pasted "stm test again" at http://paste.lisp.org/display/78128
11:45	slashus3	What is causing the strange print results? Since running was set to false and I await all of the agents, should the function only return when all of the agents are finished?
11:46	Chouser	await only waits for actions dispatched from the current thread or agent.
11:48	stuhood	its probably implemented as some kind of sentinel value in the queue that the agent acts on to call back to the awaiting thread
11:48	stuhood	~def await
11:49	stuhood	yea
11:50	slashus3	How would I go about keeping the function from returning until all of the agents have finished their business?
11:51	Chouser	you could use CountDownLatch yourself.
11:51	slashus3	Is there any other way?
11:52	Chouser	genearlly if you need specific blocking behavior for task management, you'll need to use something from java.util.concurrent
11:53	slashus3	I think I found the solution.
11:53	Chouser	One exception is 'future', but I doubt that would help you here.
11:54	lisppaste8	slashus2 annotated #78128 "fixed?" at http://paste.lisp.org/display/78128#1
11:54	slashus3	Chouser: I made the send-off the last thing in the agent.
11:54	slashus3	I guess it sort of fixes the problem?
11:55	kotarak	Where do the file and line information in the exceptions come from? I set Compiler/LINE and Compiler/SOURCE, but get only Unknown Source...
11:56	stuhood	slashus3: you'd still have a race
11:56	Chouser	slashus3: not really. I'm still seeing extra prints after the fn returns
11:56	Chouser	slashus3: and I don't think await is doing you any good there.
11:57	stuhood	anything generated by the last action sent to the agent will go into the queue after the Latch sent in by (await)
11:57	slashus3	Mine counts to 49 every time. I suppose I may get that result if I run it enough times.
11:58	Chouser	kotarak: (binding [source-path "foo"] (eval '(asdf)))
11:58	Chouser	that works for me.
11:58	slashus3	Would it make the difference than I am on a single core computer?
11:59	stuhood	slashus3: that might hide the race condition, yea
11:59	kotarak	Chouser: Hmm.. source-path. Is this handled in the Reader? The compiler seems to use Compiler/SOURCE....
11:59	Chouser	kotarak: those are the same Var
12:00	slashus3	ugh... I didn't think this would be so hard.
12:00	Chouser	,clojure.lang.Compiler/SOURCE
12:00	clojurebot	#'clojure.core/source-path
12:00	kotarak	hmmmm.....
12:01	Chouser	slashus3: why don't you want to use CountDownLatch? make one that starts at 2, then have each agent action countdown when they quit running.
12:01	Chouser	then you can await on the latch, and it'll block until they're done.
12:02	slashus3	Chouser: I need to figure out how to use it.
12:02	Chouser	slashus3: or perhaps stop having the agents send to themselves -- do a regular loop that terminates if @running is false. Then await should do what you want.
12:02	clojurebot	we can't stop here! this is bat country!
12:02	stuhood	i think rhickey chose to call them Agents instead of 'Actors' for a reason: the mainloop case isn't what he was going for
12:03	Chouser	though that's how he uses them in the ant demo
12:03	stuhood	hmm.
12:04	stuhood	so its a single agent call then, with a function containing an infinite loop?"
12:04	slashus3	It sends-off itself
12:04	Chouser	oh, no, I meant the send-to-self loop
12:04	Chouser	right
12:05	stuhood	weird.
12:05	kotarak	Chouser: sorry, I have to ask again. I want to set the file and line numbering and the eval some def. I would expect, that then the source info is set correctly. But in the stack trace only "Unkown Source" shows up....
12:05	Chouser	the main reason I've heard for using send-to-self rather than a loop/recur is so that you can redef the action and get new behavior without restarting anything.
12:06	kotarak	Is there a remedy?
12:06	Chouser	kotarak: the example I posted above gives me this error: java.lang.Exception: Unable to resolve symbol: asdf in this context (foo:39)
12:06	stuhood	Chouser: that's true, but implementation wise your loop would be moving between threads and cores on your cpu, which would suck for performance
12:06	hiredman	Chouser: also so sends get released
12:06	Chouser	so it looks like it's getting the source name ok. I'm not sure about the line number.
12:07	kotarak	-.-
12:07	kotarak	Ok. Will try again.
12:07	Chouser	stuhood: hm could be, though moving between threads doesn't necessarily mean moving between cores, right?
12:08	kotarak	For the line number, I have this by the way: (proxy [LineNumberingPushbackReader] [reader]
12:08	kotarak	(getLineNumber [] (+ offset (proxy-super getLineNumber)))))
12:08	kotarak	Proxy is cool. :)
12:08	stuhood	perhaps the agent could simple loop calling a defn'd fun, and then you could redefine the fun
12:08	erohtar_	i have to ask again (having network problems) -
12:08	slashus3	Should I be using regular java threads with this, or is this the right way to model the problem?
12:08	clojurebot	?
12:08	erohtar_	is there a way to use the binding form meta-programmatically
12:09	kotarak	erohtar_: you have to use Var/push(pop)ThreadBindings directly.
12:10	erohtar_	kotarak: those methods accept a map? the vars are passed as keys?
12:10	kotarak	erohtar_: yes, what binding uses underneath.
12:11	erohtar_	where can i find the documentation?
12:11	slashus3	I have no idea how to use CountDownLatch here.
12:11	slashus3	Do I send the latch to the agent?
12:11	erohtar_	kotarak: where can i find the documentation? is there javadoc?
12:11	stuhood	slashus3: it would be in a var, like 'running'
12:11	kotarak	erohtar_: no, but you can look at the definition of binding
12:12	erohtar_	ok
12:12	kotarak	~def binding
12:12	stuhood	slashus3: when the agents are done running, have them .countDown on the latch
12:12	slashus3	(.countDown agt alatch)
12:12	erohtar_	kotarak: will do, thanks!
12:13	Chouser	(defmacro nil-binding [n & body] (apply @#'binding [n nil] body))
12:13	Chouser	kotarak: how about that?
12:14	Chouser	hm
12:15	Chouser	wait, what's wrong again with: (defmacro nil-binding [n & body] `(binding [~n nil] ~@body))
12:15	stuhood	slashus3: (.countDown alatch)
12:16	stuhood	Chouser: perhaps what is missing is some kind of agent shutdown functionality that prevents new items in the queue for the agent
12:16	clojurebot	Chouser might make night
12:17	kotarak	Chouser: I'm not sure what's the nil about, but I want a driver for binding that takes a map (programmatically created at runtime) and a thunk being invoked as the body. A macro won't help here.
12:17	Chouser	stuhood: well, there is shutdown-agents, but that's rather a large hammer
12:17	Chouser	kotarak: ah, right of course. Sorry, took my eye off the ball there.
12:17	slashus3	(shutdown-agents) messes up everything after that. Maybe something a little lighter wait.
12:17	slashus3	weight*
12:18	stuhood	slashus3: yea
12:19	slashus3	I am looking at the source code for await, and I don't see what I would do that would be different than what await does with CountDownLatch.
12:19	Chouser	so right, you have to use the static methods of Var directly.
12:20	stuhood	slashus3: await adds the latch to the end of the agent queue, but the agent is running in a separate thread, and it can add an item after the latch
12:22	stuhood	so immediately after await returns, it will run the queued action
12:23	stuhood	actually, i guess you could await it twice?
12:24	stuhood	ah, no.
12:25	Chouser	you need to make sure the countDown is done after the agent has noticed that @running is false
12:25	Chouser	I think the only way to do that is in the agent action itself -- when it sees @running false, countDown.
12:26	slashus3	Chouser: I tried running the agent's body in a (while @running , but the output just bursts out at the end, and I still get some weird output.
12:26	stuhood	slashus3: actually, i think running await twice will work
12:27	Chouser	hm, that's an interesting point -- you might need to (flush) too, to prevent output coming after the prompt.
12:27	slashus3	stuhood: It seems like it should.
12:28	stuhood	because the first time guarantees that the @running has been seen, and the second time makes sure that the final action queued from within the agent is cleared
12:28	slashus3	That isn't a very elegant solution though.
12:28	slashus3	If that is the case, in the await function, could you just (send agent count-down) twice?
12:29	stuhood	no, you have to wait for the first (await) to return
12:29	slashus3	okay
12:29	stuhood	because when it returns there may-or-may-not be one last action sitting in the queue, which you need to wait for
12:30	slashus3	I think await would be more useful if it had the wait until all queued agents were finished.
12:31	stuhood	agreed.
12:32	stuhood	maybe (await-shutdown) that would prevent new actions for an agent
12:32	slashus3	(await-shutdown agt1 agt2 print-agt)
12:37	slashus3	maybe (await-shutdown can be implemented by just calling await twice on the agents sent in?
12:37	stuhood	the only problem would be the agent api changes: (send) would need a 'agent is shut down' failure case
12:37	stuhood	slashus3: that works here because you only have two threads adding to the agent queue
12:37	slashus3	Wait, that only works because I am using running
12:37	slashus3	Okay, yeah
12:39	stuhood	slashus3: maybe you could bring this use case up on the list?
12:39	stuhood	you shouldn't have to resort to java code to accomplish this
12:39	slashus3	I wonder what would be the best way to present it? With this example?
12:40	stuhood	you only need 1 agent to demonstrate it
12:43	stuhood	oh... (send) already has an error case if (shutdown-agents) has been run
12:44	stuhood	so there would be good symmetry with a (shutdown-agent) function
12:45	kotarak	Chouser: just for the records: the Vars to modify are SOURCE and SOURCE_PATH. I'm not sure, but it seems, that one has to set both... Now it works. :D
12:46	slashus3	stuhood: Would we have to use that exception when we determine if there are no agents in the agent queue?
12:46	slashus3	Can't we just loop through the agents and (.getQueueCount a)
12:47	slashus3	When all of the agent's (.getQueueCount a) is zero, we are finished?
12:51	slashus3	Hmm this seems to work.
12:53	lisppaste8	slashus2 annotated #78128 "fixed??!" at http://paste.lisp.org/display/78128#2
12:53	slashus3	stuhood: Check this out.
12:55	slashus3	Maybe I should await before the while in that function.
12:57	slashus3	stuhood: Because not-every is not atomic, I want to be sure that there are no further agents being emitted.
12:57	slashus3	sent
12:57	slashus3	Then I would wait until the queue was empty.
13:01	lisppaste8	slashus2 annotated #78128 "added await to the await-shutdown" at http://paste.lisp.org/display/78128#3
13:02	slashus3	Chouser: Would this be an acceptable solution?
13:08	rosejn	Should any object implementing Associative be usable both like (obj :foo) and like (:foo obj)?
13:08	rosejn	I'm implementing it in a proxy for a storage layer, and it only works with the key first.
13:08	slashus3	That seems to be the case.
13:10	rosejn	It seems that this error shouldn't be feasible then:
13:10	rosejn	actual: java.lang.ClassCastException: clojure.proxy.java.lang.Object$Associative cannot be cast to clojure.lang.IFn
13:11	slashus3	hmm
13:11	slashus3	Maybe not then.
13:11	rosejn	Yeah, strange...
13:13	kotarak	rosejn: It probably has to implement clojure.lang.IFn to be used in the functions position.
13:13	rosejn	hmmmm, ok. I'll give it a try.
13:13	rosejn	kotarak: thanks
13:14	kotarak	rosejn: invoke with one and two arguments is probably enough. (thing key) and (thing key default-if-not-found). This is the usual behaviour of maps, IIRC. You can have look at their implementation.
13:17	slashus3	kotarak: Looks like AFn takes in IPersistentMap
13:19	slashus3	rosejn: APersistentMap extends AFn, which takes in an IPersistentMap.
13:29	rosejn	awesome!
13:29	rosejn	kotarak: that worked, thanks
13:29	rosejn	just had to implement invoke
13:29	kotarak	rosejn: good to hear :)
13:31	rosejn	kotarak: Hey, you do vimclojure right?
13:31	kotarak	rosejn: right
13:31	rosejn	cool. Quick question. In a number of places it seems to indent more than I want it to.
13:32	kotarak	rosejn: do you have an example?
13:32	rosejn	For example:
13:32	rosejn	(deftest my-test []
13:32	rosejn	(test-stuff ...))
13:32	rosejn	Where I'd like the (test-stuff ...) to just be two spaces over.
13:33	kotarak	rosejn: ok. try this: :setlocal lw+=deftest
13:33	kotarak	Does this work for you?
13:33	rosejn	great
13:33	rosejn	yeah, that worked
13:34	kotarak	rosejn: You can put such clauses in ~/.vim/after/ftplugin/clojure/my-lispwords.vim. I'm working on some heuristic, but it will likely be fragile.
13:35	rosejn	got it, thanks for all the work you've done for vim
13:35	kotarak	np
13:35	rosejn	I'm using it daily now, with the repl and everything
13:35	rosejn	fairly often I get errors and I have to restart the ng-server though
13:35	rosejn	it would be nice if it could be started automatically
13:36	rosejn	also if there were a way to clear the repl state, to load libraries fresh
13:36	kotarak	Hmmm... I'll look into starting it automatically. However, the next version will be more robust on missing server.
13:36	rosejn	great
13:36	kotarak	you can reload libraries via (require :reload-all 'the.library)
13:37	rosejn	yeah, but weird errors can crop up on redefinition after refactoring things
13:37	rosejn	like moving a function from one namespace to another, where they were using each other
13:37	rosejn	it complains of multiple definitions, so you have to unmap the original
13:38	kotarak	Ah. Ok. That may happen.
13:41	kotarak	Hmm... Maybe some Repl command like ",nuke the.library".
13:42	rosejn	yeah, that would be perfect
13:43	rosejn	maybe it should be a different argument to require... (require :fresh 'my-lib)
13:44	rosejn	Actually, I guess those are just functions being called by require.... so a new function that nukes then reloads.
13:47	kotarak	rosejn: Thanks for the feedback. Gotta go to bed now. Bye.
13:48	rosejn	kotarak: thanks for the tools. Guten abend.
14:11	replaca	erohtar_: if you want to see an example of binding using runtime discovered maps, look at clojure/contrib/pprint/pprint.clj
15:30	cp2	hiredman: kevin.clj for life !
15:31	hiredman	kitten: totally
15:31	hiredman	er
15:31	hiredman	:(
15:39	cp2	why are the clojure shirts on zazzle so expensiv
15:39	cp2	e
15:39	cp2	i dont want to pay like $60 for 3 shirts
15:54	Drakeson	how can I pop a certain element (nth) of a vector or list, whichever is easier?
15:56	cp2	what would you name a 3 byte integer value? im trying to think of something that doesnt sound lame
15:56	hiredman	pop?
15:57	Drakeson	hiredman: I want to remove nth element of a vector/list
15:58	hiredman	Drakeson: vectors and lists are not designed for that sort of behaviour
15:58	hiredman	you might look at filter or remove
15:59	cp2	hiredman: any suggestions ? :)
15:59	hiredman	tryte
15:59	cp2	ah
15:59	cp2	i like that
15:59	cp2	thanks
16:03	Drakeson	hiredman: deleting an element from a linked-list is very cheap, once you can refer to the element. It sounds a bit strange if it is not implemented here.
16:03	Drakeson	so, I guess I am missing something
16:06	hiredman	,(doc pop)
16:06	clojurebot	"([coll]); For a list or queue, returns a new list/queue without the first item, for a vector, returns a new vector without the last item. If the collection is empty, throws an exception. Note - not the same as next/butlast."
16:07	hiredman	Drakeson: but clojure's library is based around sequences, not linked lists
16:08	Cark	it isn't cheap to find the nth element of a list in order to delete it
16:08	Cark	that's what sets are there for
16:08	hiredman	(doc rvec)
16:08	clojurebot	Excuse me?
16:08	Cark	though i agree that this function is missing
16:11	Cark	,(doc ordered-set)
16:12	clojurebot	java.lang.Exception: Unable to resolve var: ordered-set in this context
16:12	Cark	,(doc order-set)
16:12	clojurebot	java.lang.Exception: Unable to resolve var: order-set in this context
16:12	Cark	,(doc sorted-set)
16:12	clojurebot	"([& keys]); Returns a new sorted set with supplied keys."
16:14	Drakeson	Cark: thanks
16:14	Cark	this was for my information, not trying to help you !
16:15	Cark	sometimes you need the ordered nature of a list and the add/remove capabilities of a set
16:15	Cark	that would require an ordered set data structure
16:15	Cark	but there is none in clojure
16:15	Drakeson	what I feel is missing (or I cannot find) is a standard way to point to an element (O(n) for finding nth in a list), and then call an imaginary pop-by-ref and get a new list without that element.
16:16	Cark	well you can use filter
16:16	Cark	it's "kind of" O(1) as it's lazy
16:21	cp2	O(1) (no guarantees!)
16:24	stuhood	~def c.l.Agent
17:06	dysinger	If I call (with-open #^javax.mail.Folder folder forms*) is it going to not work because close takes true/false (expunge) ?
17:06	dysinger	I can try it just curious
17:06	dysinger	if there was any magic
17:06	stuhood	ha, i had the same question and never tried it, because i assumed there wasn't =/
17:06	stuhood	magic, that is
17:09	dysinger	that's what I figured
17:09	dysinger	you only get so much magic for free
17:10	stuhood	i love with-open though
17:11	stuhood	it's more complete in python, with the 'with' statement and context managers
17:11	dysinger	yeah - ruby has similar with closure blocks
17:14	stuhood	i guess the java way would be to add an interface that an object could implement to play nicely with 'with-open'
17:14	stuhood	and otherwise clojure would just attempt to call close()
17:15	dysinger	or you could wrote an alternate macro
17:15	stuhood	mm, indeed
17:15	stuhood	~def with-open
17:33	dakrone_hb	is anyone else having trouble building clojure-contrib using the clojure jar from svn?
17:34	Raynes	dakrone_hb: What do you mean by building? Compiling it? Usually you just jar it or copy the directories.
17:34	dakrone_hb	Raynes, http://pastie.org/439181
17:35	dakrone_hb	I was under the impression that you needed to build it
17:36	dakrone_hb	given the Getting Started page lists building it with ant
17:36	Raynes	dakrone_hb: Just cd to the directory of clojure-contirbs build file and "ant build"
17:37	dakrone_hb	Raynes, Target "build" does not exist in the project "clojure-contrib".
17:37	dakrone_hb	is the error
17:37	danlarkin	dakrone_hb: yeah, just "ant"
17:37	dakrone_hb	danlarkin, yea, I get http://pastie.org/439181
17:37	danlarkin	you don't need to specify clojure.jar
17:37	Raynes	I didn't mean to quote build, just ant.
17:38	danlarkin	that's only if you want to AOT compile
17:38	dakrone_hb	danlarkin, even though it warns that I should?
17:38	dakrone_hb	oh, okay
17:38	dakrone_hb	it warns things like pretty print won't work
17:38	Raynes	Enclojure has some neat new REPL features!
17:38	dakrone_hb	is thhat correct?
17:38	Raynes	:D
17:38	danlarkin	is your clojure up to date?
17:39	danlarkin	make sure you're on the google code SVN and not the sourceforge SVN
17:39	Raynes	All it does is jar everything, you don't even really have to jar it at all. All the ant script does is jar whats in src.
17:39	dakrone_hb	danlarkin, Ahhhhhhhhhh
17:39	dakrone_hb	danlarkin, it's been a while since I checked out ;)
17:39	dakrone_hb	danlarkin, how long ago did Clojure switch?
17:40	danlarkin	December? I think?
17:40	dakrone_hb	that would definitely be some changes
17:41	dakrone_hb	danlarkin, I'm sure this will fix it, thank you much
17:45	danlarkin	dakrone_hb: let us know if it doesn't
17:46	hiredman	~latest
17:46	clojurebot	latest is 1338
17:51	dakrone_hb	danlarkin, worked great, thanks :)
17:59	danlarkin	dakrone_hb: fantastic
17:59	dysinger	whats the best idiom for recur on exception with a finally ?
18:00	dysinger	it says I cant recur because my recur is not on the tail
18:02	dysinger	~(loop [x 1] (try (println "hello") (catch Throwable t (recur x))))
18:02	clojurebot	BUENOS DING DONG DIDDLY DIOS, fRaUline dysinger
18:03	dysinger	seems like retry on exception is common enough for IO stuff
18:03	dysinger	at least for the computerwebs and tcp/ip
18:04	dreish_	The only think I can think of would be a little ugly, so I'd wrap it in a macro, but you could return either a value or the exception, then check outside the try; if it's an exception, recur.
18:05	danlarkin	you could also possibly use a trampoline
18:05	dreish_	(defmacro retry-on-exception [& exprs] ...)
18:11	dysinger	clojure so totally scratches my lisp itch but with tens of thousands of libs
18:11	dysinger	yayz
18:28	replaca	dakrone_hb: I just added the pretty print stuff to contrib and it require AOT, thus the warning
18:28	replaca	so now it's better to do a "real" compile
18:29	Chouser	replaca: was requiring AOT necessary or just convenient?
18:30	replaca	Chouser: necessary, cause I need to make classes that wrap java.io.Writer
18:30	replaca	*needed
18:30	Chouser	and proxy was insufficient?
18:30	replaca	Chouser: remember our discussions from a looong time ago
18:31	Chouser	heh. apparently not.
18:31	replaca	I tried super-hard to make proxy work but it just didn't have what I needed
18:31	Chouser	you needed some state and a sane way to get at it from the object itself?
18:31	replaca	I came up with an idea for a super-proxy, but I haven't done that yet
18:31	replaca	yeah, there's actually a lot of state in the current application
18:32	Chouser	I've gotten into the habit recently of deriving a proxy class from something and also implementing IDeref
18:32	replaca	cause all the info is kept in the writer
18:32	dakrone_hb	I'm sorry for the dumb question, but what does AOT stand for?
18:32	clojurebot	for is not used often enough.
18:33	replaca	Ahead of time compilation
18:33	dakrone_hb	replaca, ahh, thanks
18:33	Chouser	then I can implement the deref method, and use @ to get at whatever object state I need.
18:33	replaca	But really, Chouser :gen-class is not something to be afraid of!
18:34	Chouser	I don't fear it. I dislike it.
18:34	replaca	:-)
18:34	hiredman	not afraid, annoyed by
18:34	Chouser	"make" is for C++ and Java.
18:35	replaca	But, more to the point, PrettyWriter has a bunch of methods on the class that make sense as methods
18:35	slashus2	Chouser: Sorry to bring this up again, but did you ever see my solution to the agent problem?
18:35	replaca	Chouser: or Lisp or Haskell - everything but perl, ruby and python
18:36	replaca	and even python guys use the compiler for stuff they load all the time
18:36	replaca	thus the plethora of .pyc files
18:37	Chouser	slashus2: interesting. I assume it works?
18:38	slashus2	Chouser: It seems to work on my dual core machine.
18:38	Chouser	replaca: optional AOT for performance or whatever doesn't bother me, but Clojure is has so much less state than other systems, it's a shame to require the on-disk state of compilation just to accomplish a particular task.
18:38	replaca	One nice thing about :gen-class is that the implementation can be completely dynamic, only the interface requires loading
18:38	slashus2	Chouser: I think the function should probably be called await-finished instead of await-shutdown.
18:38	Chouser	replaca: yes, it's a pretty impressive compromise, but still not as nice as proxy.
18:38	replaca	Chouser: yeah, I hear you. Unfortunaltely what I was doing here was really writing a Java class in clojure
18:39	replaca	Chouser: if proxy worked for the use case, yes :-)
18:39	slashus2	Chouser: Maybe I should make a proposal on the list?
18:39	Chouser	slashus2: two possible issues: you're doing a busy wait after the blocking await, and you're using an implementation detail of agents
18:39	replaca	the alternative was pretty limiting, where you wouldn't be able to be pretty across calls
18:40	Chouser	replaca: hm. giving up user features isn't acceptible.
18:40	replaca	which would be nasty for apps that were reformatting larger chunks of stuff
18:40	Chouser	slashus2: of the two, the busy wait would bother me more.
18:40	replaca	but I still like the idea of a super-proxy :-)
18:40	slashus2	Chouser: Is there a way to do it without the busy wait?
18:44	Chouser	slashus2: it's important to be mixing refs and agents like this?
18:46	slashus2	huh?
18:46	Chouser	agt1 and agt2 sotre state that you apprently aren't using
18:47	Chouser	store
18:47	slashus2	Chouser: I could probably do it a different way, but I was testing out refs.
18:47	Chouser	ok
18:48	slashus2	It was only an exercise to learn the behavior of agents, etc.
18:48	Chouser	sure
18:48	Chouser	I'm just feeling out the constraints of your exercise. :-)
18:49	slashus2	There are probably many situations were you would want to wait until all of the agents finish their queues before returning a function.
18:54	lisppaste8	Chouser annotated #78128 "a couple options for slashus2" at http://paste.lisp.org/display/78128#4
18:54	hiredman	slashus2: I would uses agents for that
18:54	hiredman	er
18:54	hiredman	wouldn't
18:55	hiredman	for map/reduce you can use pmap/reduce
18:55	hiredman	pmap uses the agent threadpool via futures
18:56	replaca	Chouser: do you have some examples of your proxy + Ideref solution - I'll look at that and see if I could use it
18:57	slashus2	Chouser: So there is no general solution like my await-shutdown that doesn't use a busy wait?
18:58	Chouser	slashus2: oh, there may be... perhaps using watchers or something.
18:59	slashus2	hiredman: I know this isn't the best way to do this, but I was just wanting to try out the behavior of the STM.
19:00	Chouser	replaca: this is on a different topic, but includes an example of proxying IDeref to carry some mutable state: http://groups.google.com/group/clojure/msg/79a09fa877cb48d0
19:01	replaca	Chouser: thanks, I'll check it out
19:02	Chouser	ok, g'night all.
19:02	slashus2	Chouser: Hmm. Watchers monitor for a change of state... goodnight
19:03	replaca	goodnight Chouser
19:09	slashus2	I wonder why I would want to use a watcher inside of a watch in this case.
19:09	slashus2	instead*
19:23	rlb	Is there already any easy way to treat a large binary file of 64-bit integrers as a (lazy) sequence?
19:24	rlb	s/integrers/integers/
19:35	replaca	rlb: not that I know of, but duck-streams/read-lines does it with strings. Maybe you could adapt it?
20:42	banisterfiend	what's the name of the clojure repl?
20:43	rlb	replaca: ok, thanks. One of the things I'm trying to do is keep track of what's effectively a 10 or so million element hash table mapping 128-256 bit values to an integer triple. I may just use sqlite or jdbm, but I was just looking around clojure itself...
20:43	rlb	banisterfiend: in debian, it's clojure-repl, but otherwise I just invoked it manually.
20:43	rlb	banisterfiend: If you mean the class, it's clojure.lang.Repl.
20:44	banisterfiend	thx
20:44	rlb	and if you want readline-alike:
20:44	rlb	java -cp /usr/share/java/jline-0.9.94.jar:/usr/share/java/clojure.jar:/usr/share/java/asm3-commons.jar:/usr/share/java/asm3.jar jline.ConsoleRunner clojure.lang.Repl
20:44	banisterfiend	is tehre another name for the repl?
20:44	banisterfiend	i think i installed it ages ago, but i cant remember what it's called
20:44	banisterfiend	clojure-repl doesn't work
20:45	rlb	Well, the repl class is in clojure.jar.
20:45	rlb	(normally)
20:47	banisterfiend	thanks rlb
20:47	banisterfiend	you have mad skillz
21:20	cp2	Microsoft Boasts 96% Netbook Penetration
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22:57	tsdh	Hi. In my clojure code I want to run a java classes main method. That's no problem, but is it also possible to do that in an own JVM with own JVM args?
23:18	cgrand	tsdh: if you want to start another JVM then there's no more facility than for starting a random program. See clojure.contrib.shell-out
23:20	tsdh	cgrand: Basically what I want is something like ant's fork, e.g. the new JVM should use the same classpath, etc. But ok, I'll use shell-out till I find something that suits my needs better.