#clojure – 2009-06-03

2009-06-03

01:16	sunwukong	is there a function in core/contrib for #(filter identity %) ?
01:17	sunwukong	(that is, removing every nil/false element from a coll)
01:59	replaca	sunwukong: not that I can think of off hand
01:59	sunwukong	ok, thanks
07:41	cemerick	whew, the rhickey interview from qcon is done in a very unpleasant format, IMO
07:42	arbscht	got a link?
08:00	cemerick	arbscht: http://www.infoq.com/interviews/hickey-clojure
08:00	arbscht	thanks
08:00	cemerick	it's sort of an interview, but the interviewer is sitting in the audience, which strikes me as odd
08:18	gnuvince	cemerick: that interview is not really good IMO because the interviewer sticks mostly to his notes and is generally boring
08:18	cemerick	yeah, that too :-)
08:20	gnuvince	Interviewers should be more like Simon Peyton-Jones
08:24	cemerick	I don't think I've seen him interview anyone.
08:26	gnuvince	Me neither, I mean that the interviewer should be enthused and engaging instead of sitting his butt on a chair and just going through a list of questions.
08:44	cemerick	the treatment of the last map in an apply form as a seq of args can lead to some very hard-to-diagnose bugs
08:45	cemerick	I guess I'm supposed to know what I'm doing with all this rope ;-)
08:46	Chouser	heh
08:50	eliantor	hi
08:51	Chouser	eliantor: hello
08:51	cemerick	Chouser: what's your take on the UI stuff from javaone? I was pretty bummed about the consistent soft-pedaling of swing.
08:52	Chouser	cemerick: didn't pick up on that. you're referring to the big javafx push in the keynote?
08:53	eliantor	i'm trying to do something like this: (map + [[1 2 3] [1 2 3]]) --> [2 4 6]
08:53	cemerick	I saw a bunch of tweets about sun people saying they're "still planning on supporting swing", jwebpane maybe being released alongside jdk7, but not included in the jre, etc.
08:54	cemerick	twitter rumors are probably not the best thing to go by, but it's what I've got right now :-)
08:54	eliantor	i mean how can i inline a list to provide it to map?
08:54	Chouser	,(apply map + [[1 2 3] [1 2 3]])
08:54	clojurebot	(2 4 6)
08:54	eliantor	thanks
08:54	eliantor	:)
08:55	cemerick	also:
08:55	cemerick	,(map + [1 2 3] [1 2 3])
08:55	clojurebot	(2 4 6)
08:55	cemerick	if you have distinct collections
08:55	Chouser	cemerick: hmph. and is javafx their replacement for it, or am I confused.
08:55	cemerick	ech, join the club.
08:56	cemerick	they don't have much of any story around javafx widgets that would be the analog of those available in swing, so I don't see how they can expect people to make the jump.
08:57	cemerick	Maybe all UIs are supposed to be done in photoshop or their "JavaFX Designer" vaporware :-P
08:57	Chouser	you know, the canvas 2d api isn't that complicated -- if you've got a canvas-based ui toolkit you like, what about something that proovides not a full browser stack, but just a canvas compatible api?
08:57	Chouser	do you have a canvas-based ui toolkit you like? :-)
08:58	cemerick	canvas-based UI toolkit? Like dojo, or whatever?
08:58	Chouser	cemerick: I dunno, I thought that's why you wanted jwebpane
09:00	cemerick	I want jwebpane for a variety of reasons. Most of all, I don't want to be dragging a "legacy" toolkit around everywhere, and there's going to be light and heat around canvas for the next decade at least.
09:08	cemerick	is there a "deep" map merge somewhere? (deep-merge {:a #{1 2}} {:a #{3 4}}) => {:a #{1 2 3 4}}
09:08	cemerick	ah, deep-merge-with, perhaps :-)
09:59	drewr	Reminder: Clojure Search http://www.google.com/coop/cse?cx=004621955734675372103:0oxuogeollc
10:07	lisppaste8	cgray pasted "gen-class problem" at http://paste.lisp.org/display/81280
10:08	chillitom	i think I've just realised a massive problem with my UniqueBlockingQueue.. because all methods are synchronized a call to take() can never return if the queue is empty
10:08	cgray	so I'm having trouble figuring out why the class that I'm generating isn't getting loaded properly...
10:09	chillitom	damn conncurency is difficult!
10:09	Chouser	chillitom: yeah, that's actually a feature. :-)
10:09	Chouser	.take not returning is a feature, I mean, not that concurrency is complex. :-/
10:10	cgray	java.lang.IllegalStateException: Cannot create AdaptiveSignalSystemControler for class name:
10:10	cgray	playground.cgray.adaptivecontroler
10:10	cgray	any ideas?
10:11	Chouser	cgray: That's not all in one file, is it?
10:11	cgray	Chouser: no, after add-classpath is in a different file
10:12	Chouser	hey, you know what though -- if all you're doing is implementing an interface, I highly recommend proxy over gen-class, even if you intend to compile to .class files.
10:12	cgray	I don't think that works in my case. I have to give the name of the class to an xml file
10:13	Chouser	bah. ok.
10:13	Chouser	well, the first thing I'd try is getting rid of the add-classpath
10:14	Chouser	set your classpath on the command line with -cp and then try compiling
10:14	cgray	what do you mean?
10:15	Chouser	java -cp clojure.jar:src clojure.main
10:15	Chouser	then you can bind compile-path to "src" and try compiling.
10:15	Chouser	add-classpath is unreliable.
10:16	cgray	ok, good to know
10:19	cgray	hmm, from the command line I get a ClassNotFoundException on the interface that I am trying to implement
10:19	cgray	and it's in a jar that's on the classpath
10:20	cgray	no, never mind
10:20	cgray	the jar wasn't on the classpath :)
10:21	Chouser	:-)
10:24	cgray	ok, so it compiles. how would I test if it can actually be loaded?
10:26	Chouser	(new playground.cgray.adaptivecontroler)
10:26	rys	http://www.infoq.com/news/2009/06/g1-free-or looks like Sun changed the wording on G1 in the latest update to 6
10:26	Chouser	(.givenSignalGroupIsGreen (new playground.cgray.adaptivecontroler))
10:28	dnolen	rys: good
10:28	cgray	the first one worked, the second one didn't
10:28	Chouser	cgray: odd. What kind of error did you get?
10:28	cgray	No matching field found
10:30	Chouser	oh, it wants an arg. my bad.
10:30	Chouser	(.givenSignalGroupIsGreen (new playground.cgray.adaptivecontroler) nil)
10:30	cgray	thanks, I should have caught that :)
10:33	Chouser	cgray: so add-classpath was the only thing you had to change?
10:33	cgray	so it works at the repl, but when the larger application tries to call it, it still barfs... at least I know that problem isn't with clojure though...
10:41	cgray	Chouser: I missed your question. I think it was working, I just wasn't testing it properly.
10:41	Chouser	oh, even with add-classpath it was working?
10:42	cgray	I think
10:42	Chouser	ok
10:56	cemerick	is there a deep macroexpand anywhere yet?
10:56	gnuvince	Not built-in
10:56	gnuvince	I don't know about clojure-contrib
10:57	cemerick	well, clojure.contrib.macros doesn't have one, which I presume would be where it'd be.
10:57	cgrand1	konrad has put a macroexpand-all in contrib
10:58	cemerick	ah, it's in walk
10:59	cgrand1	or mexpand-all in macro-utils
11:02	cgrand1	walk/macroexpand-all seems to not care about locals nor special symbols
11:03	stuartsierra	cgrand1: yes, that's true, but it should still work
11:09	Chouser	Why doesn't this work: (defn #^bytes foo [])
11:09	dnolen	isn't that a primitive type?
11:16	cemerick	hrm, type-hinting issues is this week's theme
11:17	Chouser	dnolen: it means an array of primitive bytes when used in other type-hinting contexts.
11:17	dnolen	primitive arrays aren't Objects
11:17	dnolen	functions can only return Objects
11:18	dnolen	this is what the whole boxing issue on primitive types is all about
11:18	Chouser	,(make-array Byte/TYPE 10)
11:18	clojurebot	#<byte[] [B@8bb8b2>
11:18	Chouser	what's that?
11:18	dnolen	the repl printing out a primitve, this probably uses reflection I'm assuming.
11:19	dnolen	could be wrong of course, but this was the take away when rhickey explained it.
11:19	Chouser	no, I think you're incorrect. make-array is a function, and it's returning a thing
11:19	Chouser	,(instance? Object (make-array Byte/TYPE 10))
11:19	clojurebot	true
11:19	dnolen	but that might be boxed right?
11:20	Chousuke	,(class (make-array Byte/TYPE 10))
11:20	clojurebot	[B
11:20	cemerick	Chouser: maybe defn doesn't play well with the primitive hints? {:tag (Class/forName "[b")} ?
11:20	Chousuke	:P
11:20	Chouser	I think a primitive can't be returned by a clojure function, but an array of primitives is fine.
11:20	Chousuke	hmm
11:21	Chousuke	the bash prompt git branch addition is nice
11:21	Chousuke	now I no longer need to type "git branch" to know where I am.
11:22	cemerick	speaking of git, my quick experiment to keep patches on top of a git-svn clone of clojure's svn didn't go well. Apparently, one cannot push git-svn state to a git remote...?
11:22	Chousuke	I think it's possible somehow manually though.
11:22	danlarkin	I think that (instance? Object (make-array Byte/TYPE 10)) comes back as true because passing the array to instance? boxes it? since it's a function boundary?
11:22	dnolen	Chouser gotcha, dunno then.
11:23	dnolen	,(instance? Object (ints (make-array Integer/TYPE 10)))
11:23	clojurebot	true
11:23	Chouser	danlarkin: make-array is clojure function -- the thing that it returns has to obey the same rules as any args would.
11:23	stuartsierra	You can do (defn #^"[B" my-function ...)
11:24	dnolen	,(instance? Object (int 1))
11:24	clojurebot	true
11:25	dnolen	no way that is true
11:25	Chousuke	,(class (int 1))
11:25	clojurebot	java.lang.Integer
11:25	danlarkin	it's the function boundary
11:25	dnolen	yes
11:25	Chouser	stuartsierra: ouch. But yes, that works fine. Thanks.
11:26	Chouser	int is not a plain function
11:26	dnolen	,(instance? Object 1)
11:26	clojurebot	true
11:26	Chouser	1 is a boxed object
11:26	dnolen	than how can you know that something is primitive?
11:26	Chouser	do it in a big loop and see if it's slow?
11:27	dnolen	haha
11:27	Chouser	:-)
11:27	stuartsierra	dnolen: arguments to Clojure fns are always boxed.
11:27	Chousuke	~def instance?)
11:27	clojurebot	Excuse me?
11:27	Chousuke	oops
11:27	Chousuke	~def instance?
11:27	dnolen	stuartsierra: yeah.
11:28	Chousuke	,(.isInstance (int 1) Object)
11:28	clojurebot	java.lang.IllegalArgumentException: No matching method found: isInstance for class java.lang.Integer
11:28	Chouser	it's hard because primitives are boxed almost without you even touching them.
11:28	Chousuke	,(.isInstance Object (int 1))
11:28	clojurebot	true
11:29	Chouser	boxed!
11:29	Chousuke	evil
11:29	danlarkin	we're experiencing the quantum phenomenon, where observing a thing inherently changes it!
11:29	stuartsierra	You can only get primitives in a loop.
11:30	aravind	hi
11:30	Chouser	the real problem is that you want to be able to see what the compiler concludes about stuff. This is after read, after macro-expand, but before bytecode-generation.
11:30	Chouser	The compiler's got an AST that describes all it's conclusions, but it's hard to get to and opaque.
11:30	Chouser	clojure-in-clojure will fix that, and allow questions like this to be answered well.
11:32	Chouser	,(clojure.lang.Compiler/analyze clojure.lang.Compiler$C/EXPRESSION '(int 5))
11:32	clojurebot	#<StaticMethodExpr clojure.lang.Compiler$StaticMethodExpr@138009b>
11:32	dnolen	so has anyone tested, are chunked-seqs as fast as loop/recur?
11:32	Chousuke	aren't they potentially faster :/
11:33	dnolen	that would be great
11:33	aravind	I have a for loop that that acts on a list of two items generates a sequence of two lists, something like ((1 2 3) (4 5 6)). however, I want it to generate a map with two entries, one for each of the entries in the for seq.
11:33	Chousuke	unless you loop over chunks I guess.
11:33	Chouser	I thought rhickey claimed he had tests showing they were faster in some cases.
11:33	aravind	I have been trying all kinds of combinations but I finally gave up..
11:33	Chouser	aravind: I don't understand -- what should the map look like?
11:33	Chouser	{1 4, 2 5, 3 6} ?
11:34	aravind	okay, the for acts on (:a :b) and generate ((1 2 3) (4 5 6)), I want the final map to be {:a (1 2 3) :b (4 5 6)}
11:34	Chousuke	,(map list [[1 2] [3 4] [5 6]]); you mean you have something like this?
11:34	clojurebot	(([1 2]) ([3 4]) ([5 6]))
11:34	Chousuke	er, whoops
11:34	Chousuke	,(map list [1 2] [3 4] [5 6]); you mean you have something like this?
11:34	clojurebot	((1 3 5) (2 4 6))
11:35	Chouser	,(zipmap [:a :b] '((1 2 3) (4 5 6)))
11:35	clojurebot	{:b (4 5 6), :a (1 2 3)}
11:36	aravind	hmm..
11:36	aravind	,(zipmap (:a :b) '(((1 2 3) (4 5 6))))
11:36	clojurebot	{}
11:37	dnolen	aravind: (:a :b) is not a quoted list
11:37	dnolen	aravind: also why are you using lists instead of vectors, lists are rarely the right choice.
11:37	dnolen	,(zipmap [:a :b] [[1 2 3] [4 5 6]])
11:37	clojurebot	{:b [4 5 6], :a [1 2 3]}
11:37	aravind	dnolen: all that stuff is autogenerate from java iterators (or some sort of java arrays).
11:38	aravind	dnolen: I have to somehow conver them to be sequences to use them in clojure, and (seq java-form), only generates lists?
11:38	dnolen	(vec (make-array Integer/TYPE 10))
11:38	dnolen	,(vec (make-array Integer/TYPE 10))
11:38	clojurebot	[0 0 0 0 0 0 0 0 0 0]
11:38	dnolen	you can convert java arrays into vectors
11:39	Chousuke	aravind: seq doesn't generate lists; it generates seqs :)
11:39	dnolen	,(vec (seq '(1 2 3 4)))
11:39	clojurebot	[1 2 3 4]
11:40	aravind	okay, but doesn't it feel like an aweful lot of convertions.. just to be able to use the results?
11:40	Chousuke	if you have seqs there's no need to put them in a vector usually, but sometimes it helps
11:40	Chousuke	but if you're typing out literal sequences, '(1 2 4 5 232 43232) is rather unclojurey
11:40	Chousuke	vectors are more idiomatic in that case.
11:41	aravind	dammit, I swear I looked through zipmap, but it didn't strike me as something I could use for this.
11:41	dnolen	aravind: heh Clojure is like that. most of the things you could think of for operating on sequences is already there.
11:42	aravind	so something like (zipmap (vector generating-array) final-generated-array) should work for my case.
11:43	aravind	dnolen: yeah, for a while there, I was actually calling the java iterator and stepping through next.. before I read about seq :(
11:43	Chouser	,(let [compiler-type #(let [e (clojure.lang.Compiler/analyze clojure.lang.Compiler$C/EXPRESSION %)] (.getJavaClass e))] (compiler-type '(int 5)))
11:43	clojurebot	int
11:43	Chouser	,(let [compiler-type #(let [e (clojure.lang.Compiler/analyze clojure.lang.Compiler$C/EXPRESSION %)] (.getJavaClass e))] (compiler-type '(+ 5 10.5))))
11:43	clojurebot	java.lang.Number
11:43	dnolen	heh cool
11:43	Chouser	,(let [compiler-type #(let [e (clojure.lang.Compiler/analyze clojure.lang.Compiler$C/EXPRESSION %)] (.getJavaClass e))] (compiler-type '(+ (int 5) (float 10.5)))))
11:43	clojurebot	float
11:43	dnolen	c.c.compiler-helper?
11:46	aravind	thanks guys, that works beautifully. Sometimes I should just give up sooner and beg for help
11:46	dnolen	perfect macro for checking what the compiler sees for a given expression.
11:48	Chouser	I'm afraid it might add to confusion...
11:59	Chousuke	Chouser: I just wonder when clojure-in-clojure is actually going to materialise.
12:00	Chouser	Chousuke: it's not next on Rich's list, I think, but not last either.
12:00	Chousuke	I guess rhickey is going to have to implement the instance thing first
12:00	Chouser	he said that, but I don't understand why yet.
12:01	Chouser	compiler-type's a bad name for that thing. What should I call it?
12:01	Chouser	,(let [compiler-type #(let [e (clojure.lang.Compiler/analyze clojure.lang.Compiler$C/EXPRESSION %)] (when (.hasJavaClass e) {:class (.getJavaClass e) :primitive? (.isPrimitive (.getJavaClass e))}))] (compiler-type '(+ (int 4) 5)))
12:01	clojurebot	{:class java.lang.Number, :primitive? false}
12:02	Chousuke	compiler-info
12:02	Chousuke	hmm
12:02	stuartsierra	compiler-tag
12:02	Chousuke	you could expand the function to return as much compiler knowledge as you can and return a map.
12:03	Chouser	well.. that's what clojure-in-clojure does. ;-)
12:03	Chousuke	heh
12:03	Chouser	I guess not really.
12:03	Chousuke	your code as it is looks a bit scary :P
12:04	Chouser	in general, or in this case?
12:04	Chouser	:-D
12:04	Chousuke	I mean in the clj-clojure code you have on github
12:04	Chouser	oh. yeah. ugly.
12:04	Chousuke	50 lines is a lot for a lisp function.
12:05	Chouser	what's there is largely the result of a (incomplete) learning process on my part. It probably ought to be scrapped and written from scratch.
12:06	Chouser	but then Compiler.java is over 5000 which is (I hope) a lot for a .java file.
12:07	Chousuke	fairly large, yes :P
12:09	cemerick	an optional string arg should be added to time that is appended to the elapsed time printlns.
12:11	Chouser	"expr-info"?
12:11	cemerick	yeah, something along those lines
12:14	Chousuke	people are too fond of abbreviating things IMO ;P
12:14	Chouser	Chousuke: "expression-information"?
12:15	Chousuke	I think just expression-info would be fine :)
12:15	cemerick	current-expression-timing-description gets my vote
12:17	Chousuke	I just think the programmer's fingers don't matter as much as the burden on the reader :P
12:18	stuartsierra	speak for yourself -- I have carpal tunnel and tendinitis. :)
12:18	cemerick	There's certainly a balance to be had. Some of the names in CL are abominations, for instance.
12:18	Chousuke	... and most IDEs and editors have keyword completion anyway
12:19	cemerick	oh-no -- not the "IDEs will save us from ourselves" bit
12:19	cemerick	That's the #1 counterargument to "java/C# is too verbose"
12:19	cp2	personally i like the cl names
12:19	Chousuke	cemerick: in this case, I think "expr-info" would be too abbreviated simply because it's difficult to pronounce if you read it aloud.
12:19	arohner	replaca?
12:20	Chousuke	I still have no idea what that does.
12:20	Chouser	"ehk-SPRINFO"
12:20	dnolen	sexpr-info
12:20	Chousuke	looks like a misspelling of replica :/
12:20	Chouser	sex-pr-info
12:21	cemerick	cp2: least-negative-normalized-double-float?
12:22	arohner	Chousuke: it's surprisingly hard to google for the definition of replaca
12:22	duck1123	does anyone know why the tests for clojure.contrib.sql are showing up in the documentation on the wiki?
12:22	Chousuke	arohner: heh
12:22	arohner	but there are two functions, replace car, and replace cdr
12:22	arohner	replacA, replacD
12:22	Chousuke	so why couldn't they just keep the r
12:22	cp2	cemerick: lol
12:22	Chousuke	that would have made it a LOT better.
12:23	arohner	or even replace-car
12:23	Chousuke	; I totaled my Toyota ;(
12:23	arohner	though early lisps may have had a limit on the fn name length
12:24	cemerick	yeah, it was 7 chars in the really early days
12:24	arohner	though I'm amazed car and cdr stuck around as long as they did
12:32	arohner	does anyone else find themselves writing (interleave (keys map) (vals map)) a lot?
12:33	stuartsierra	only in macros
12:33	arohner	several core fns want a flat seq of key value pairs, but (seq map) returns ([k v] [k v]). I find myself needing to fix that often
12:34	Chousuke	,(apply concat {1 2 3 4})
12:34	clojurebot	(1 2 3 4)
12:34	stuartsierra	I wrote a flatten-map function, I think it's in contrib somewhere.
12:35	stuartsierra	Chousuke: that's better.
12:35	arohner	that is a better solution. Though I'm kind of wondering why there are fns that take lists of key value pairs rather than a map
12:36	Chousuke	they're usually map-constructing functions I suppose
12:36	stuartsierra	Before array-map, maps were unordered, too.
12:38	cemerick	stuartsierra: perhaps test-is/testing should emit a separator between different context names? I see it puts a space there now, but something more to indicate the separation between levels would be good. first context / second context / third ... etc.
12:39	stuartsierra	cemerick: I was copying RSpec, where concatenating the contexts is supposed to yield a complete sentence.
12:40	cemerick	oh, I see
12:40	cemerick	heh, that seems really unlikely to work out, except in contrived examples
12:40	stuartsierra	That's why I don't like it.
12:41	cemerick	"when only the demo slides matter..."
12:41	arohner	that's never stopped ruby before
12:43	cemerick	Chousuke: I just noticed your msg from earlier -- are you OK?
12:44	Chousuke	cemerick: you mean the toyota one? fortunately that was a joke on replace-car. :)
12:44	cemerick	HA!
12:55	replaca	arohner: despite my nick, the CL funcs are rplaca, rplacd, iirc
12:56	replaca	http://www.lispworks.com/documentation/HyperSpec/Body/f_rplaca.htm#rplaca
14:19	hiredman	When he was pointed out that Clojure is already doing what he wants, he said "Well, I don't like the square brackets" :-(
14:20	danlarkin	who said that?
14:21	hiredman	http://www.artima.com/weblogs/viewpost.jsp?thread=259505 The EuroLisp Symposium and the Future of Common Lisp
14:21	hiredman	Scott McKay
14:22	danlarkin	This seems accurate, "The impression I got is that he would only accept as new Common Lisp a language designed by himself..."
14:24	hiredman	"one sends his proposal to the CDR site and nothing happens"
14:27	replaca	If Clojure's as successful as that language about which people say, "I don't like the fact that whitespace is syntactically significant," I'll be happy. :-)
14:27	replaca	the rest of the world can dislike our parens and square brackets
14:27	hiredman	http://infoworld.com/d/developer-world/java-get-more-modular-jdk-7-upgrade-919 "Class path is dead,"
14:29	Chouser	huh
14:34	Chousuke	nice and vague: "The modularity aspect gives us a taste of how perhaps we're getting to a point where we can start to think about how we might end up with one Java" :P
14:36	wwmorgan	is there a function in core or contrib that takes a directory and returns all files under it, traversing the directory structure?
14:37	slashus2	wwmorgan: Tried file-seq?
14:37	wwmorgan	slashus2: that's it. Thanks
14:38	mrsolo	is there better way to do this? (defn unique [a] (sort (into () (set a))))
14:38	mrsolo	minus the sort part
14:38	Chouser	'a' is any collection?
14:38	mrsolo	ya
14:39	mrsolo	or just list if that matters
14:39	Chousuke	sorted-set?
14:39	Chousuke	or did that exist
14:39	danlarkin	Yess, down the classpath!
14:39	mrsolo	basically i wants to remote duplciates '(1 2 2) -> '(1 2) etc
14:39	Chouser	set is probably faster than sorted-set
14:39	Chousuke	right
14:39	Chousuke	Chouser: but he's going to sort anyway
14:40	Chouser	(seq (set a)) should do it
14:40	mrsolo	sort isn't necessary..but i found that the elements order aren't guanarntee after transformation...
14:41	Chousuke	right.
14:41	Chousuke	is the original seq containing the duplicates sorted?
14:41	mrsolo	it contains duplicated, not sorted
14:42	mrsolo	but i couldn't figure out a way to collaps item in place
14:42	mrsolo	so.. will just enforce sort order
14:42	Chousuke	are the duplicates always adjacent?
14:42	mrsolo	no
14:42	Chouser	can you just use a set in your algorithms instead of a list?
14:42	Chousuke	okay, so putting stuff in a set is probably better.
14:42	mrsolo	hmm
14:43	mrsolo	may be let me check
14:44	hiredman	~def clojure.set/union
14:45	hiredman	a lot of the operations in clojure.set call seq or use functions that call seq :(
14:47	mrsolo	hmm probably not.. i uses lots of concat mapcat filter etc.. the change isn't worth it..
14:47	Chouser	(expression-info '(+ (int 5) (float 10))) ==> {:class float, :primitive? true}
14:48	hiredman	ooo
14:49	cemerick	Chouser, Dark Lord of the Cons
14:50	danlarkin	neat
14:51	Chouser	(expression-info '(/ 5 2)) ==> {:class java.lang.Number, :primitive? false}
14:51	Chouser	(expression-info '(/ (int 5) (int 2))) ==> nil
14:52	Chouser	(expression-info '(/ (float 5) (int 2))) ==> {:class float, :primitive? true}
15:30	cemerick	hrm, trying to print refs that have metadata fails reliably
15:30	cemerick	oh, only those that have :type metadata
15:31	Chouser	that's because the printer dispatches on :type
15:31	Chouser	it's a feature!
15:32	hiredman	I feel a disturbance
15:32	cemerick	Chouser: right, but there's a :default dispatch for print-method. The problem is that the fn for :default tries to dissoc the :type metadata out of the object being printed (which might also be a feature? ;-) )
15:33	hiredman	as if millions of abstractions had just become concrete
15:38	danlarkin	the fu is strong with you
15:40	stuartsierra	Anyone know a decent Java SSH library?
15:41	hiredman	apache may have one
15:42	hiredman	looks like not
15:42	stuartsierra	nope
15:42	StartsWithK	jsch
15:42	StartsWithK	http://www.jcraft.com/jsch/
15:42	stuartsierra	I've tried JSch and j2ssh, both are clumsy and poorly documented.
15:42	StartsWithK	http://www.ganymed.ethz.ch/ssh2/
15:43	StartsWithK	if all fails try this one
15:43	StartsWithK	i haven't used it
15:43	stuartsierra	No longer maintained, by the original author or Trilead.
15:43	StartsWithK	but looks complete
15:44	StartsWithK	trilead died like 2 weeks ago
15:44	hiredman	http://mina.apache.org/sshd/
15:44	hiredman	:/
15:44	StartsWithK	they deleted public repo and everything :/
15:44	hiredman	http://mina.apache.org/sshd/embedding-sshd-in-5-minutes.html <-- thats kinda cool
15:44	StartsWithK	jna+native ssh libs?
15:44	StartsWithK	that will be my last option too
15:45	stuartsierra	No JNA, I'd rather call the command-line client.
15:45	stuartsierra	MINA looks interesting.
15:45	hiredman	mina is the framework the twitter guys used for their scala thing
15:46	hiredman	#java doesn't seem to be fond of it, but #java is also home to an author of a competing framework
15:46	StartsWithK	grizzly? :)
15:47	hiredman	something affiliated with jboss
15:48	stuartsierra	What's the jboss one?
15:48	hiredman	xnio maybe?
15:49	hiredman	the issue with the framework whosename I can't remember is it is annotation driven, which is bad for clojure integration
15:49	stuartsierra	xnio looks like a sockets library
15:50	StartsWithK	mina has ssh client? or server only?
15:50	stuartsierra	that's what I'm trying to figure out
15:50	StartsWithK	ssh/sftp?
15:51	hiredman	Apache SSHD is a 100% pure java library to support the SSH protocols on both the client and server side.
15:51	hiredman	This library is based on Apache MINA, a scalable and high performance asynchronous IO library.
15:51	hiredman	SSHD does not really aim at being a replacement for the SSH client or SSH server from Unix operating systems, but rather provides support for Java based applications requiring SSH support.
15:53	stuartsierra	It does include a SshClient class, though.
15:54	StartsWithK	and in the frist example it looks dead simple to use it (at the top of .java file)
16:07	stuartsierra	"NoClassDefFoundError: org/apache/mina/core/future/IoFutureListener"
16:13	StartsWithK	it looks like it requires main mina distribution to work, http://svn.apache.org/repos/asf/mina/trunk/core/src/main/java/org/apache/mina/core/future/IoFuture.java
16:29	arohner	is there a way to use -> if the result should go into an arg other than the first?
16:29	hiredman	arohner: yes, but it isn't pretty
16:30	hiredman	,(-> 1 (#(/ 3 %)))
16:30	clojurebot	3
16:30	arohner	hmm
16:30	arohner	thanks
16:30	cemerick	template should be able to make that better eventually...
16:30	cemerick	(if not already)
16:30	arohner	template?
16:31	cemerick	clojure.contrib.template
16:31	cemerick	I've only used it in the context of test-is, but controlling placement of values in -> seems like a natural next step
16:32	cemerick	what hiredman showed is clearly easier than what you'd have to do right now using template, but a -> variant that explicitly used it shouldn't be too difficult.
16:34	arohner	thanks
17:06	bhurt	Is there a retry for Clojure transactions, like Haskell's retry? Basically, it just aborts the current transaction and waits until one of the STM ref cells you accessed has been written, and then retries the transaction.
17:08	hiredman	sounds icky
17:08	bhurt	Ugly to implement, granted, but really useful.
17:09	hiredman	for what purpose?
17:10	bhurt	So I have a ref cell holding a map. If the element I'm looking for isn't in the map (and some other conditions hold), another thread is going to add the element RSN. A retry in this case would be exactly what I want to do.
17:11	Chouser	I just wrote await-iref, which you could do before entering your transaction.
17:11	stuartsierra	Reading a ref doesn't require a transaction.
17:11	hiredman	bhurt: you could just, you know, loop
17:11	bhurt	I don't want to busy wait.
17:12	Chouser	I haven't gotten rhickey's attention yet to see if the goals of await-iref are inherently flawed. :-)
17:12	hiredman	I think I'd use a blockingqueu
17:13	Chouser	http://paste.lisp.org/display/81237#2 -- await-iref (tested)
17:13	Chouser	bhurt: so that's not a busy loop, but I'm not sure it's a good idea either.
17:13	hiredman	thread B does a blocking .take from the queue and thread A, when it updates the map, pushes some token into the queue
17:14	Chouser	There are plenty of existing concurrency mechanisms that might suffice: Semaphore, BlockingQueue, etc.
17:14	bhurt	A blocking queue might work...
17:14	bhurt	A Semaphore would work as well.
17:15	Chouser	in my case, most of the time nobody cares when I'm updating the ref -- seems a shame to create/update a Semaphore every time.
17:16	Chouser	So if I want to block on it, I use await-iref (which uses add-watch and a Semaphore) to block until some condition is met.
17:17	bhurt	I only create the semaphore when I'm inserting the element.
17:17	hiredman	:/
17:18	bhurt	This isn't that performance sensitive.
17:20	replaca	Chouser: I like that! A good use case for watchers.
17:21	Chouser	replaca: thanks, but like I said I'm a little worried I'm just unaware of some more correct alternative.
17:22	Chouser	Or I guess more that this would be seen as an abuse of iref's or wathes or seomthing.
17:22	replaca	Chouser: you never know until you ask. Watchers are still marked experimental
17:22	replaca	but I'm using them in the object explorer thing I'm presenting tonight
17:23	Chouser	ha!
17:23	Chouser	oh, watchers
17:23	Chouser	yes, good.
17:23	Chouser	something like watchers will be around. I think what's "experimental" is the specific API which has already been adjusted a couple times.
17:24	replaca	I drive the UI off a set of refs so you can update it interactively or programattically
17:24	replaca	and the various parts of the UI just watch the parts they're interested in
17:24	replaca	(basically like cells)
17:24	Chouser	yes, very good.
17:25	AWizzArd	~ seen kotarak
17:25	clojurebot	kotarak was last seen quiting IRC, 8606 minutes ago
17:25	AWizzArd	,(/ 8606.0 60)
17:25	clojurebot	143.43333333333334
17:25	AWizzArd	,(/ *1 24)
17:25	clojurebot	java.lang.IllegalStateException: Var clojure.core/*1 is unbound.
17:26	Chousuke	clojurebot has awful attention span :)
17:35	mrsolo	what is ~ in front of variable in defmacro for?
17:36	Chousuke	unquote
17:36	Chousuke	,(let [foo 5] `(foo ~foo))
17:36	clojurebot	(sandbox/foo 5)
17:36	hiredman	,(let [a 1] `(n ~a d))
17:36	clojurebot	(sandbox/n 1 sandbox/d)
17:36	mrsolo	thanks
18:40	gnuvince_	Is anybody getting these reflection warnings in the svn version?
18:40	gnuvince_	Reflection warning, /home/vince/prog/clojure/clj-starcraft/dump.clj:3 - reference to field getClass can't be resolved.
18:40	gnuvince_	Reflection warning, /home/vince/prog/clojure/clj-starcraft/dump.clj:3 - reference to field getClassLoader can't be resolved.
18:42	slashus2	gnuvince: yes
18:45	durka42	what else should I compile to get c.c.fnmap working? ant -Dclojure.jar=../clojure.jar didn't do it (java.lang.ClassNotFoundException: clojure.contrib.fnmap.PersistentFnMap)
18:46	gnuvince_	Wel..
18:47	gnuvince_	Arch updated the JDK to 6u14
18:47	slashus2	gnuvince: I don't know.
18:47	gnuvince_	No change in my Starcraft program
18:47	gnuvince_	:(
18:47	slashus2	gnuvince_: Did you activate the G1GC?
18:47	gnuvince_	It's not on by default?
18:47	slashus2	no
18:47	durka42	no you need some scary arguments
18:47	slashus2	-XX:+UnlockExperimentalVMOptions -XX:+UseG1GC
18:48	gnuvince_	(and regardless, I don't think this would make the difference I'm looking for)
18:48	slashus2	Try and see if that makes any difference at all.
18:48	durka42	PS, they rewrote ("clarified") the thing about G1GC requiring a support contract
18:48	durka42	now it just says it may eat your pets when turned on
18:49	Chousuke	gnuvince_: you said you had some performance problems with that starcraft thingy?
18:50	gnuvince_	Chousuke: not so much "problems" as "I'm annoyed that it's not more within Java's range"
18:50	gnuvince_	slashus2: slower with G1GC
18:50	slashus2	nooooo
18:51	Chousuke	gnuvince_: where does most of the time go, though? :/
18:51	slashus2	Run it over and over again to make sure there were no anomalies.
18:51	gnuvince_	Chousuke: hang on, I'll run a few profile runs
18:52	slashus2	gnuvince_: Have you played around with visualvm?
18:52	gnuvince_	slashus2: not yet
18:53	gnuvince_	Though I imagine the numbers won't be much different from -Xrunhprof
18:53	slashus2	no
18:53	slashus2	It will just be prettier.
18:53	Chousuke	gnuvince_: I have the feeling that boxing things might be hurting performance
18:54	Chousuke	it's something that's fairly difficult to detect and avoid :/
18:54	gnuvince_	Chousuke: the most costly calls change from profile run to profile run
18:55	gnuvince_	But it's between java.nio.Buffer.position and clojure.lang.Cons.first
18:55	gnuvince_	java.lang.reflect.Array.setInt also takes a sizeable percentage
18:56	Chousuke	hmm
19:00	Chousuke	so what clojure function is calling these?
19:00	gnuvince_	Split between parsing the actual binary data and converting it to something "sensible" to the domain
19:02	gnuvince_	Chousuke: if you want to play around with it, the code is on BitBucket and I can pack you up a bunch of data files to test
19:03	Chousuke	I might.
19:03	gnuvince_	Although my guess is that to attain Java-like performance, I'm going to need to radically change my approach
19:05	Chousuke	if you have a link to the data files, give me that and I'll download them for later use. I'm going to go to sleep soon but I can poke around tomorrow.
19:08	gnuvince_	Chousuke: uploading now
19:09	Chousuke	oh damn, I need to install hg
19:15	gnuvince_	argh
19:18	Chousuke	hmm
19:19	Chousuke	in make-reader using aset-int looks suspicious
19:22	gnuvince_	using aset or aset-int changes nothing
19:23	gnuvince_	Oh come on!
19:23	gnuvince_	I'm uploading the file
19:23	gnuvince_	Site has a problem with it
19:24	dreish	Drawing a blank. Isn't there something equivalent to (dorun (for ...))?
19:24	Chousuke	I would assume that it wants a primitive int as the value you're putting in it, but that looks like a boxed value in all cases :/
19:25	Chousuke	dreish: doseq?
19:25	dreish	Thanks. For some reason I was thinking that was the same as doall.
19:25	dreish	I blame the heat.
19:26	Chousuke	gnuvince_: plus that it has to do reflection I think because the return type of (mask-fn (getter buf)) is not known at compile time.
19:26	gnuvince_	Chousuke: looking at Clojure's code, all aset-* functions use the reflection framework
19:26	gnuvince_	So I think I'm pretty screwed there.
19:26	gnuvince_	I tried to cast pretty much everything in that code block without success
19:26	Chousuke	~def aset-int
19:29	Chousuke	gnuvince_: have you tried using a plain old vector?
19:31	Chousuke	hm
19:31	gnuvince_	I used one in the very early stages, but switched to an array for some reason
19:32	gnuvince_	god damn
19:33	gnuvince_	I can't upload this stupid file to senduit or at work
19:33	gnuvince_	sigh
19:33	Chousuke	gnuvince_: :/
19:33	gnuvince_	I'll try a friend's server
19:34	Chousuke	well, if you get some data available somewhere, ping me. I really have to go get some sleep now. I'll investigate more later.
19:35	gnuvince_	damn
19:35	gnuvince_	it always stalls
19:36	gnuvince_	I'm beginning to think I'M the problem
19:36	rhickey	replaca: ping
19:36	gnuvince_	ok
19:40	ataggart	is there a way to clear out whatever junk I've added to the namespace when working in a repl? (other than ^D)
19:41	replaca	rhickey: yeah
19:41	rhickey	replaca: all set? seems like a big crowd
19:41	replaca	yeah!
19:41	rhickey	I have a 10 minute talk prepped on chunked seqs
19:42	replaca	it's going to be cozy. Who knew you were so popular?!
19:42	replaca	rhickey: sorry all presentation slots filled.
19:42	replaca	(joking!)
19:42	rhickey	Also, I saw the latest IntelliJ plugin - awesome. Can we squeeze in a few minutes for Ilya to demo?
19:42	replaca	sure.
19:42	replaca	I'd love to see it
19:42	rhickey	should be great - I'm heading out soon
19:43	rhickey	thanks for putting this together
19:43	replaca	cool, phil, amit and a couple of others are already here working on swamiji stuff
19:43	replaca	*swarmiji
19:43	rhickey	see you soon
19:43	replaca	np, it's fun
19:44	dreish	I made a repl that runs things in the background if they take longer than repl-timeout seconds.
19:44	replaca	i'll put you on last (to lead in to town hall) and ilya right before you
19:48	gnuvince_	are you guys both at JavaOne or something?
19:49	replaca	a bunch of us just live here
19:49	replaca	a few are here for javaOne and a couple of others (like technomancy) are in just for the meetup
19:49	gnuvince_	ok
19:53	tbatchelli	I work a block away from the meetup venue :)
19:53	replaca	tbatchelli: hope you don't get stuck in traffic! :-)
19:53	replaca	luckily, the Giants are out of town
19:54	tbatchelli	replaca: if you guys need any help I can come over right now (I am bored)
19:56	replaca	Feel free to come when you want, but we're pretty well set up.
20:07	ataggart	I guess quite a few of us work in soma
20:12	replaca	now live from the SF clojure meetup!
20:23	dysinger	<crickets>
20:26	tashafa	how would ai go about creating a byte array in clojure?
20:30	hiredman	,(make-array Byte/TYPE 10)
20:30	clojurebot	#<byte[] [B@1926603>
20:31	hiredman	,(into-array Byte/TYPE [1 2 3 4])
20:31	clojurebot	java.lang.IllegalArgumentException: argument type mismatch
20:31	hiredman	bah
20:31	hiredman	,(into-array Byte/TYPE (map byte [1 2 3 4]))
20:31	clojurebot	#<byte[] [B@1c65470>
20:35	tashafa	thanks hiredman!
20:36	tashafa	(doc byte)
20:36	clojurebot	"([x]); Coerce to byte"
20:52	dreish	http://gist.github.com/123364
21:29	technomancy	is there a significant overhead to running with the JVM args that jdb needs?
21:30	technomancy	-agentlib:jdwp=transport=dt_socket,address=8021,server=y,suspend=n
21:34	dysinger	there is overhead
21:34	dysinger	I don't have any stats
21:34	stuhood	i assume it would have to instrument every class and method
21:42	technomancy	obviously you wouldn't do it in production, but I wonder if it's worth leaving on in development
21:42	technomancy	just so you don't have to restart when you realize you need it.
21:44	replaca	i love it that you two are chatting while sitting right next to each other
21:45	dysinger	does jdp actually instrument byte code? I thought it just inspected things as it was running.
21:45	dysinger	I don't know though
21:47	dysinger	Yeah I don't think it would hurt anything to run it locally like that most of the time.
21:47	dysinger	if no debugger is connected - it just wont debug
21:48	technomancy	cool; adding it to my .emacs then
21:49	dysinger	one thing is this though - you can't run two on the same port
21:49	dysinger	so you could only have one slime sess
21:51	durka42	you could come up with some clever way to auto-generate the port
21:52	dysinger	but you need the port number to connect the debugger
21:52	dysinger	so you'd have to go look if you weren't using the default port
21:52	dysinger	=====
21:52	dysinger	somebody ask him if they use emacs underneath !
22:10	technomancy	oh bummer; if you try to start a Clojure instance with a jdb port that's in use it just fails to launch Clojure itself rather than just leaving jdb out.
22:20	chessguy	is it correct to say "a symbol can refer to a var that is bound to a value"?
22:20	chessguy	i would have expected to see "a symbol can refer to a var to which is bound a value"
22:21	chessguy	sounds strange to me to talk about something getting bound to a value instead of the other way around
22:25	lisppaste8	ozzilee pasted "Nested Macro Definitions" at http://paste.lisp.org/display/81329
22:25	technomancy	btw, you can vote for Clojure to get uploaded to the official mvn repos here: http://jira.codehaus.org/browse/MAVENUPLOAD-2464
22:26	ozzilee	I'd like write a macro that only exists inside another macro, as above. defaction outside of defservice should be an error. Is there something better than codewalking?
22:27	chessguy	technomancy: what's mvn?
22:27	ezyang	chessguy: Maven
22:27	chessguy	which is...
22:27	technomancy	chessguy: lets you handle dependencies in an automated fashion
22:27	technomancy	so you don't have to manually manage jar files etc.
22:27	dysinger	babble babble
22:27	stuhood	dysinger: hehe
22:28	ezyang	chessguy: If you use Debian, it's sort of like apt
22:28	chessguy	ah, ok. i don't, but i do get the analogy :)
22:28	technomancy	chessguy: it does a lot of other things, but that's the part that's relevant to clojure
22:29	hiredman	technomancy: is there a video camera in the room?
22:29	chessguy	so...do values get bound to vars, or vars to values?
22:29	dysinger	voted ?
22:30	technomancy	hiredman: yes, and there have even been loose plans announced to upload them.
22:32	ezyang	How important is it for me to learn clojure macros?
22:32	ezyang	I've touched TeX and C macros, and I'm really not relishing the prospect
22:32	technomancy	ezyang: learn macros last.
22:32	ezyang	Ok.
22:33	dreish	Seconded. They're nice, but everyone who dives into Lisp because of macros tries to use them for everything that they shouldn't be used for.
22:33	technomancy	ezyang: they're useful, but it's easy to get carried away if you're relatively inexperienced
22:34	dysinger	Y it's like saying "there is no line between your language and your application" - can make debugging hard
22:35	technomancy	I love how rich always deflects questions about internals that you shouldn't have to care about. =)
22:36	hiredman	:D
22:37	dysinger	but his whole presentation is about internals that we shouldn't have to care about !
22:37	dysinger	(chunked seqs)
22:37	dysinger	should be transparent
22:37	hiredman	dysinger: well that depends
22:37	technomancy	yeah, he mostly does that when people ask about locking/concurrency details
22:37	technomancy	because they're way more complicated than chunking
22:38	hiredman	I can imagine chunked seqs will be useful for library writting
22:38	hiredman	(well the details of)
22:38	chessguy	,String
22:38	clojurebot	java.lang.String
22:38	dysinger	richhickey just said his testing methodology is the "scream test" #heh
22:58	hermanChess	hello
22:58	stuhood	heya
23:44	arohner	clojurebot: paste
23:44	clojurebot	lisppaste8, url
23:44	arohner	clojurebot: ahem
23:44	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
23:44	clojurebot	excusez-moi
23:45	arohner	I have a goofy performance problem
23:45	lisppaste8	arohner pasted "perf problem" at http://paste.lisp.org/display/81335
23:45	arohner	I can run that test as many times as I like, and I get similar results each time
23:46	arohner	the first run is slow, and the final run is 2x faster than the first run
23:46	arohner	but between runs, I'm doing nothing
23:46	arohner	no reloading code, etc
23:47	hiredman	arohner: hotspot
23:48	arohner	I understand that if I had new code, it would take awhile to optimize
23:48	arohner	but why would it get slower between runs?
23:48	hiredman	oh
23:48	durka42	at the repl, the code is going to be compiled each time
23:49	hiredman	durka42: not in the example usage he has
23:49	arohner	but only my expression of (dotimes [i 10] (perf-test)) should be recompiled
23:49	durka42	yeah
23:49	durka42	and that shouldn't affect the optimization of performance-test...
23:50	durka42	what's in perf-test, out of curiosity
23:50	durka42	and by curiosity i mean i want to try this at my repl
23:50	hiredman	hard to say, there is always some jitter up and down in time's numbers
23:51	durka42	but you have to run with -server to enable hotspot at all, yes?
23:51	arohner_	sorry, computer trouble
23:51	arohner_	I missed everything after "not in the example he has"
23:51	hiredman	hard to say, there is always some jitter up and down in time's numbers
23:51	arohner_	that's a 2x difference though
23:51	durka42	what's in perf-test? i kind of want to try this at my repl
23:51	arohner_	just a bunch of math
23:51	hiredman	durka42: actually the also appears to be a client version of hotspot
23:52	arohner_	multiplies divides
23:52	durka42	oh ok
23:53	stuhood	the example you show looks reasonable... it can take a few thousand iterations for hotspot to optimize something
23:53	arohner_	and I'm fine with that the first time
23:54	arohner_	the problem is, if I keep running (dotimes [i 10] (perf-test)), I get the same distribution
23:54	durka42	i am not seeing that effect
23:54	hiredman	stuhood: he is asking about the large up and down in the numbers
23:54	arohner_	i.e. run 0 is always slow, no matter how many times I run the same expression
23:54	durka42	(defn perf-test [] (time (dotimes [i 20000] (+ 3 Math/PI (/ 10 7)))))
23:54	durka42	gives me pretty stable values for (dotimes [i 10] (perf-test))
23:55	arohner_	durka, I'm doing about a million multiplies and divides in each (perf-test)
23:55	durka42	paste it?
23:56	arohner_	that's kind of hard
23:57	arohner_	let me see if I can find a more representative paste
23:58	arohner_	clojurebot: paste
23:58	clojurebot	lisppaste8, url
23:58	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
23:58	lisppaste8	arohner pasted "perf problem #2" at http://paste.lisp.org/display/81338
23:59	arohner_	so there, I run the exact same line, twice in a row
23:59	arohner_	run 1 of each dotimes is slow, but run 10 of each dotimes is fast
23:59	stuhood	gotcha
23:59	arohner_	I'm ok with the first run 1 being slow. I'm not ok with the second run 1 being slow