#clojure – 2009-05-11

2009-05-11

00:11	unlink1	Does lazy-seq create a recur target?
00:12	cads	yeah, maybe I'll write all my source with an awk header that processes the file when clojure loads it
00:13	cads	but it might be better to do it in the reader :)
00:13	cads	is that stuff documented/
00:18	hiredman	unlink1: I believe so
01:09	eyeris	I need to reference a static field that is defined in a Java interface named Cell. I am unable to import the interface, using the ns macro but if I refer to a field as Cell/field_name, I get an exception due to the Cell namespace not existing.
01:11	cmvkk	i didn't realize you could refer to a static field in an interface anyway.
01:12	eyeris	http://poi.apache.org/apidocs/index.html
01:12	eyeris	See the fields inherited from org.apache.poi.ss.usermodel.Cell?
01:13	cmvkk	yeah...
01:14	cmvkk	can you reference those fields in java itself?
01:14	eyeris	I don't know. I don't have much java experience :/
01:15	cmvkk	i think you might actually need to reference the fields in a class that implements Cell.
01:15	cmvkk	(this is pure untested speculation on my part, but why would an interface have concrete values? that's not what they're for)
01:16	eyeris	Referring to the field in an implementing class worked.
01:16	eyeris	Thanks.
01:19	cmvkk	apparently you can have concrete fields in an interface like that. hmm.
01:19	cmvkk	guess it's possible you just can't access them from clojure.
01:19	eyeris	In this case, it makes some sense.
01:20	eyeris	The interface is used to represent a MS Excel cell, while the implementing classes represent two different file formats.
01:20	eyeris	But the cell types don't change.
01:20	cmvkk	right.
01:20	eyeris	Like I said, "some" sense :0
01:49	unlink	any bitterness in that api?
03:28	unlink	What's the point of clojure.core/when?
03:31	cp2	,(when (= 1 1) (println "1 is 1"))
03:31	clojurebot	1 is 1
03:31	cp2	,(when (= 1 2) (println "1 is 1"))
03:31	clojurebot	nil
03:31	cp2	etc
03:31	unlink	,(macroexpand-1 '(when :a :b))
03:31	clojurebot	(if :a (do :b))
03:32	unlink	I mean, it doesn't seem to add any value over if
03:32	cp2	well yeah
03:32	cp2	its just for convenience
03:32	unlink	But how is it more convenient?
03:32	cp2	cleaner code in some respects
03:32	cp2	its really personal preference
03:35	hiredman	if requires an explicit do
03:35	hiredman	when does not
03:35	hoeck	unlink: I was using when in common lisp code alot, because it wraps the then-expr in a do block, and so saves some nesting and typing when using multiple then-expressions
03:35	unlink	What confuses me is how it's used synonymously with if in clojure/core.clj.
03:35	hiredman	if the else exp returns nil, when is the idomatic choice in clojure
03:36	hiredman	well, if it is nil
03:37	unlink	When is if idiomatic?
03:37	hiredman	if is idomatic when you have something and something else
03:37	hiredman	(if foo a b) should be if (if foo a nil) should be when
03:38	unlink	I see
03:38	hiredman	it isn't a huge thing
03:38	unlink	So when do I use if-not and when do I use when-not?
03:38	hiredman	it's in the manual of style :P
03:38	hiredman	same
03:38	hiredman	I dunno why you would ever use if-not
03:38	unlink	that's what I mean
03:39	unlink	actually
03:39	unlink	In Python, I sometimes do (if-not (nil? a) (do something-with a) (something else))
03:39	unlink	(well, in Python syntax)
03:40	hiredman	I am teh first to admit the manual of style does not address all issues
03:41	hiredman	but it does address when
03:41	unlink	Oh, you were being serious about a manual of style?
03:41	hiredman	no, just rhickey called using when idiomatic
03:42	hiredman	The All Inclusive Clojurebot Compendium of Coding Style
03:42	unlink	gotcha
03:42	Cark	the AICCS, a must read...
03:43	Cark	good morning =)
03:43	hiredman	the awks
03:43	AWizzArd	Hey Cark
03:43	hiredman	akes?
03:43	unlink	Is 1 function : 1 class intended to forever be The Way Clojure Works (TM)?
03:44	hiredman	I dunno, but it does not seem like something that is a good idea to depend on
03:45	Cark	well my guess is that it will stay that way, so functions can implement interfaces
03:45	Cark	and for closures state too
03:45	hiredman	hmmm
03:46	Cark	mhhh actually i'm not sure about the latter, how are closures closed over in clojure ?
03:46	hiredman	no idea
03:46	AWizzArd	Cark: what are the alternatives?
03:46	unlink	,+
03:47	unlink	,(do +)
03:47	hiredman	:(
03:47	Cark	i don't know, i know they are objects in c#
03:47	unlink	:-(
03:47	hiredman	~ping
03:47	Cark	then you have the stack for real lisps
03:47	Cark	thez stack frame i mean
03:47	unlink	,(lazy-seq (recur))
03:47	hiredman	clojurebot must be lagged or something
03:47	unlink	needs to be woken up
03:48	unlink	anyway, this is slightly disturbing: user=> (new clojure.core$_PLUS___3332)
03:48	unlink	#<core$_PLUS___3332 clojure.core$_PLUS___3332@2d1e233>
03:49	clojurebot	Test
03:49	hiredman	huh
03:49	unlink	,(println "I'm awake")
03:49	hiredman	maybe I broke something
03:49	unlink	is it hosted on google code?
03:49	hiredman	,a
03:49	unlink	s/code/appengine/
03:49	hiredman	no
03:50	hiredman	it's weird, no exceptions or anything in the repl
03:50	unlink	in clojurebot's?
03:50	hiredman	yeah
03:50	hiredman	clojurebot: hello?
03:50	clojurebot	#<core$_PLUS___3330 clojure.core$_PLUS___3330@1b51af1>
03:50	clojurebot	#<core$_PLUS___3330 clojure.core$_PLUS___3330@1b51af1>
03:50	hiredman	uh oh
03:50	clojurebot	PONG!
03:51	clojurebot	Execution Timed Out
03:51	unlink	hahahaha
03:51	clojurebot	I'm awake
03:51	clojurebot	java.lang.Exception: Unable to resolve symbol: a in this context
03:51	clojurebot	BUENOS DING DONG DIDDLY DIOS, fRaUline hiredman
03:51	hiredman	ok
03:51	hiredman	~ping
03:51	clojurebot	PONG!
03:51	AWizzArd	~ max people
03:51	clojurebot	max people is 164
03:51	hiredman	something lodged in his pipe maybe
03:51	unlink	,(reduce (new clojure.core$_PLUS___3330) (range 10))
03:51	clojurebot	45
03:53	unlink	Anyway, that makes me cringe.
03:54	hiredman	so don't do it
03:55	unlink	I don't think whether I do it changes whether the underlying issue bothers me or not.
03:56	hiredman	what issue?
03:56	hiredman	that functions are classes?
03:57	unlink	right
03:57	hiredman	why is that an issue?
03:58	unlink	I mean, I can't think of a more efficient way of implementing them on the JVM.
03:58	hiredman	well, generally they are only instanciated once
03:59	hiredman	except maybe anonymous functions
03:59	hiredman	but even with those, object allocation is cheaper on the jvm then with c++
03:59	unlink	Function invocation = instantiation?
03:59	hiredman	nah
04:00	opqdonut	Function invocation = .invoke(args..)
04:00	hiredman	function invocation is a method call
04:00	hoeck	I think the clojure function implementation maps perfectly on the closures == objects analogy
04:00	hiredman	or .run or .call(Object)
04:00	unlink	ok
04:01	hiredman	,+
04:01	clojurebot	#<core$_PLUS___3330 clojure.core$_PLUS___3330@1b51af1>
04:01	hiredman	that is an instance
04:01	hiredman	.(.invoke + 1 2)
04:01	unlink	It has obvious advantages with Java interop, but means degraded performance compared to, for example, OCaml's implementation.
04:01	hiredman	,(.invoke + 1 2)
04:01	clojurebot	3
04:02	jdz	unlink: why?
04:02	hiredman	Callable is tailor made for function objects
04:02	unlink	At a minimum, all bindings which are closed on must be on the heap.
04:04	jdz	unlink: so how do you pass closures to different threads in OCaml?
04:05	jdz	if the bindings are not on the heap
04:05	unlink	OCaml cheats.
04:05	unlink	It knows when it can get away with putting them on the stack.
04:06	hiredman	~literal [1] clojure
04:06	clojurebot	cheating
04:06	jdz	you know, JIT does some crazy things, too
04:06	jdz	you never know what it comes up with sometimes
04:06	__mac	Doesn't the 1.6 hotspot do escape analysis to put local stuff on the stack
04:06	__mac	?
04:07	opqdonut	additionally, jvm really isn't a general purpose virtual machine
04:07	opqdonut	you can't mess with the stack for one
04:07	AWizzArd	jdz: is that good or bad? :)
04:07	jdz	AWizzArd: both.
04:07	AWizzArd	(to not know what it will come up with)
04:07	AWizzArd	ic
04:07	jdz	i mean, i'm old enough to not care about that stuff
04:07	jdz	but i can understand some people being nervous
04:07	AWizzArd	:p
04:08	jdz	when they don't have full control/knowledge of the underlying stuff
04:08	__mac	I'm hoping I will stop caring about that stuff one day. I have developed an unhealthy fascination with llvm...
04:08	jdz	now i feel really releaved that i can rely on amazing things others have created, like JVM and Clojure
04:09	jdz	and CL implementations :)
04:09	unlink	I never got past the (which CL implementation should I use) phase.
04:10	__mac	sbcl ;)
04:10	AWizzArd	or Allegro Enterprise
04:10	unlink	Actually, that's sort of a lie.
04:10	unlink	I got past that phase after losing interest in CL.
04:10	__mac	So the correct answer is "none, use clojure"?
04:11	AWizzArd	unlink: so after you lost interest in CL you found knew which CL you should use? ;)
04:11	unlink	Yeah...not currently using any other lisps.
04:11	AWizzArd	-found
04:12	unlink	AWizzArd: Yes, but if I evaluated that by trying to use CL I would get an NPE.
04:12	AWizzArd	unlink: when you interact with our world your are indirectly using other Lisps. The universe was coded in Lisp: http://www.gnu.org/fun/jokes/eternal-flame.ogg
04:14	jdz	c'mon, it's common knowledge that our world was cobbled together with perl in the very late night of 7th day
04:15	jdz	and nobody can fix it because it's a big pile of mess
04:16	unlink	But I heard all these jokes so many years ago :(
04:17	jdz	which jokes?
04:17	hiredman	oh wow
04:17	hiredman	that ogg crashes mplayer
04:17	hiredman	Great
04:18	unlink	must be too old
04:18	hiredman	hah
04:19	hiredman	I found a post on the mplayer list complaing about the same ogg
04:20	__mac	You all probably saw this already, but it's still good stuff:
04:20	__mac	http://xkcd.com/224/
04:26	unlink	I find it amusing that lazy-seq creates a recur target, since a recur pointing to one can only ever cause it to diverge.
04:27	opqdonut	err?
04:27	opqdonut	a lazy-seq needn't be infinite
04:28	unlink	How is a recur pointing to lazy-seq ever useful?
04:28	hiredman	lazy-seq wraps in a fn
04:28	hiredman	I think
04:29	hiredman	which is where the recur target comes from
04:29	unlink	oh you're right
04:29	unlink	(list 'new 'clojure.lang.LazySeq (list* '#^{:once true} fn* [] body)))
04:32	unlink	Wow, LazySeq is so magical.
04:32	unlink	,(class (rest (lazy-seq [1 2 3])))
04:32	clojurebot	clojure.lang.APersistentVector$Seq
04:32	hiredman	yep
04:32	hiredman	~literal [1] clojure
04:32	clojurebot	cheating
04:32	unlink	?
04:33	hiredman	it's a joke
04:33	hiredman	clojure's (and other lisps) simplicity often feels like cheating
04:33	hiredman	~clojure
04:33	clojurebot	clojure is the brand
04:33	unlink	oh
04:33	hiredman	~clojure
04:33	clojurebot	clojure is like life: you make trade-offs
04:33	hiredman	~clojure
04:33	clojurebot	clojure is far closer to perfection then python
04:33	hiredman	hmmm
04:34	unlink	I'm surprised that rest of a LazySeq isn't some other opaque object like another LazySeq
04:34	hiredman	somewhere in there it will say "clojure is cheating"
04:34	hiredman	it can be
04:35	hiredman	if the lazy-seq yields (cons 'foo (lazy-seq 'something))
04:35	unlink	well, right
04:41	unlink	why does lazy-seq need to be implementedin Java?
04:43	hiredman	~def clojure.lang.LazySeq
04:44	unlink	I mean, I've read that
04:44	talios	is there a "clojure" way of getting resources off the class path? Using (.getResourceAsStream (.getClass some.class) "/foo") seems to work (has issues with compiled clojure thou), but I get the feeling there should be something more clojure based?
04:44	hiredman	maybe a performance thing?
04:46	hiredman	talios: I have been using that with aot compiled clojure with no issues
04:49	talios	I was trying it using clojure.lang.RT as the class, which worked but wouldnt find my resources, and it doesn't seem to find my own classes that the clojure compiler is generating, unless I work out some kinda two-pass thing
04:50	talios	actually - using clojure.lang.RT worked when running locally, but not when deployed to my web container, I suspect class loader poopage
04:51	hiredman	(.getResourceAsStream (clojure.lang.RT/baseLoader) "version") is actually what I am using
04:51	talios	Ill try that using the loader
04:53	hiredman	if you are using your own gen-class you need to not do the getresource durring the compile, only durring runtime
04:53	hiredman	(when-not compile-files ...
04:54	talios	mmm - didn't know that (when-not trick! that could be handy
05:04	talios	gah - it -was- working, not I just get nulls. hrm.
05:05	unlink	~def clojure.core.ns
05:05	unlink	aw
06:07	cads	hey, I was wondering if anyone here knows about clojure.set, and the relational set operations defined there
06:11	cads	we have union and intersection and difference, and select, which operate on sets, but there is also rename, join, and project which seem to work with sets of maps
06:14	cads	can we better represent set theoretic constructions and operations in terms of operations on rel-sets?
06:54	unlink	Does such a macro as http://dpaste.com/42928/ exist in the standard library, or is it just a good idea?
07:15	AWizzArd	Hello rhickey. I wanted to ask you how easy it would be to get a hook into the compile function. Interesting for me would be to reach some level of basic code obfuscation: removing docstrings, renaming functions and the resulting .class files.
07:15	AWizzArd	Is that easily possible or would that require a loot of work?
07:16	AWizzArd	(existing code obfuscators may not be able to do that)
07:17	rhickey	AWizzArd: things like that are definitely not a priority. I guess you could get come mileage from Java obfuscators? The only thing I think will come any tome soon would be dropping docs strings, useful for memory-limited targets
07:17	rhickey	time
07:32	AWizzArd	Removing the docstrings would already be a good thing.
07:32	AWizzArd	rhickey: is it possible to run compile not on files on disk, but instead on what exists in the image?
07:33	rhickey	AWizzArd: there isn
07:33	rhickey	t really an image,
07:33	AWizzArd	I can write a function which makes up gensym'ed aliaes of all function names in a namespace and then ns-unmaps the original names
07:33	rhickey	everything is already compiled once running
07:34	AWizzArd	and can one write those compiled objects to disk?
07:35	rhickey	AWizzArd: this (obfuscation) isn't something I want to spend time on
07:36	AWizzArd	i mean i could write such a function, and it may work if one could write the compiled objects to disk
07:37	AWizzArd	for example if there is a function foo then i could do a (intern ns (gensym) (get (ns-interns ns) 'foo)) and then (ns-unmap ns 'foo)
07:37	eevar2	obfuscation is a daft idea anyway
07:37	eevar2	*concept
07:37	AWizzArd	agreed
07:37	rhickey	AWizzArd: doesn't compile write compiled files to disk?
07:39	AWizzArd	rhickey: it does, but it loads my .clj files on disk. What I have in mind would be a process like: I load my files from disk, now everything is compiled. Then I replace the names of all functions (in ram) and write those to disk. If that can be done somehow.
07:40	rhickey	AWizzArd: why does it load .clj files from disk?
07:40	AWizzArd	Currently I can replace my function names in ram. But on disk in my .clj files all names stay the same. So a call to compile would take a secret.clj and produce a secret__init.class or something like that.
07:41	AWizzArd	rhickey: I start a fresh clojure and do: (ns foo) (defn bar [] 100)
07:41	AWizzArd	Then: (binding [compile-path "/my/build/dir/"] (compile 'foo))
07:41	AWizzArd	==> java.io.FileNotFoundException: Could not locate foo__init.class or foo.clj on classpath
07:45	AWizzArd	I imagine to have a file foo.clj with the contents: (ns foo) (defn bar [] 100) Now in my build process I would (load "foo"). Then (intern ns (gensym) (get (ns-interns ns) 'bar)) and then (ns-unmap ns 'bar). Now I can call bar and it returns 100.
07:45	AWizzArd	If I could now store that manipulated namespace to disk it may do what I want.
07:55	ittayd	Hi, I have a question about multimethods
07:57	AWizzArd	Yes?
07:58	ittayd	The documentation has an example for defining an area multimethod
07:59	ittayd	the dispatching value is :Shape
07:59	ittayd	and then to define area for rectangles:
07:59	ittayd	(defmethod area :Circle [c]
07:59	ittayd	is used
07:59	ittayd	does this mean that :Shaped is applied on c and then isa? is used to match :Circle?
08:01	AWizzArd	what first happens when you call area is that the dispatch function (defmulti area :Shape)
08:01	AWizzArd	gets called
08:01	AWizzArd	:Shape can be a function in Clojure
08:01	AWizzArd	one could have said instead: (defmulti area (fn [object] (get object :Shape)))
08:02	AWizzArd	When you have (def H {:a 1, :b 2, :c 3}) then (get H :a) ==> 1
08:02	AWizzArd	But (:a H) is also ==> 1
08:03	AWizzArd	ok so far?
08:04	AWizzArd	In the example on the Clojure website r is {:Shape :Rect :wd 4 :ht 13}
08:05	AWizzArd	(area r) === (area {:Shape :Rect :wd 4 :ht 13})
08:05	ittayd	yes
08:05	AWizzArd	and (:Shape {:Shape :Rect :wd 4 :ht 13}) ==> :Rect
08:05	AWizzArd	so, (area r) will first call :Shape
08:05	AWizzArd	And that returns a value. In this case it returns :Rect
08:06	AWizzArd	Now after that happened Clojure will look up all defmethod's.
08:06	AWizzArd	One of those is: (defmethod area :Rect [r] (* (:wd r) (:ht r)))
08:07	AWizzArd	That is the one that gets executed
08:07	AWizzArd	[r] is the parameter - that gets bound to the orginial input of the call to area. That was {:Shape :Rect :wd 4 :ht 13}.
08:07	ittayd	thanks for the explanation
08:07	AWizzArd	np, hope it shed some light into multimethods
08:08	ittayd	sure did. it would be useful if this explanation of the flow appeared in the docs.
08:10	AWizzArd	ittayd: for another example look at http://paste.lisp.org/display/68846
08:12	ittayd	nice and confusing
09:07	AWizzArd	rhickey: did you get my email (it may have landed in a filter)?
09:35	chessguy_work	'morning
09:37	AWizzArd	Hi chess
09:37	chessguy_work	so i think i'm going to take on a chess project in clojure
09:37	chessguy_work	a truly symbolic chess engine
09:38	chessguy_work	should be fun
09:52	chessguy_work	wow don't everyone get all excited at once :)
09:56	AWizzArd	ah, but that sounds good, yes
09:57	AWizzArd	Will it be an open source project?
09:57	kotarak	:D
09:58	hiredman	obviously all the money is in closed source chess engines...
09:58	AWizzArd	hiredman: maybe chessguy_work should also make a closed source one. It is possible that he can come up with the strongest chess engine ever.
09:59	AWizzArd	I was very surprised about Rybka. Some companies were working for 20 years, with international chess experts, but the Rybka programmer came up with a new idea and within 6 months he got the strongest program. Duh!
10:01	chessguy_work	heh
10:02	chessguy_work	rhickey, one step at a time
10:02	chessguy_work	as for whther or not it will be open source....we'll see
10:03	gnuvince	chessguy_work: do you have a blog?
10:03	chessguy_work	not one i keep updated
10:03	gnuvince	ok
10:03	gnuvince	It would've been interesting to follow your progress
10:03	chessguy_work	just hang around here :)
10:04	chessguy_work	and/or the mailing list
10:04	gnuvince	Let me know if you find optimization techniques ;)
10:04	chessguy_work	what sort of optimization techniques are you interested in?
10:05	gnuvince	chessguy_work: pretty much anything that can bring a Clojure program within 1.5-2x the speed of an equivalent Java program.
10:05	gnuvince	See this: http://gnuvince.wordpress.com/2009/05/11/clojure-performance-tips/
10:05	chessguy_work	oh
10:05	chessguy_work	i'm more interested in algorithmic techniques
10:05	gnuvince	chessguy_work: in the case of my project, I don't know what algorithmic techniques I could use to improve the efficiency of the program
10:06	chessguy_work	what project would that be?
10:06	gnuvince	It reads data from a ByteBuffer and transforms it into Clojure data structures.
10:06	liebke	gnuvince: nice tips
10:06	chessguy_work	oh sorry
10:06	gnuvince	chessguy_work: clj-stracraft. There's a quick background in the post.
10:06	chessguy_work	i guess i should have read your link
10:07	AWizzArd	gnuvince: do you constantly update that site?
10:07	gnuvince	AWizzArd: I try to. Maybe 3-4 posts per month
10:08	AWizzArd	Maybe you could set up a static link that will always stay valid and has an overview about everything you found out?
10:08	gnuvince	AWizzArd: if I have enough material, I could probably do that, Wordpress allows "static" pages.
10:09	chessguy_work	gnuvince looks like a great blog
10:09	chessguy_work	don't see an RSS link though
10:11	gnuvince	chessguy_work: if you use Firefox, you should see an orange RSS icon in your address bar
10:11	gnuvince	Otherwise: http://gnuvince.wordpress.com/feed/
10:12	chessguy_work	ah, nice. added
10:12	chessguy_work	i was using chrome :)
10:12	gnuvince	OK
10:13	gnuvince	If you have comments (positive or negatives), corrections, suggestions, don't hesitate to post them.
11:30	dnolen	curious, why would in some case using aset-int slow down a tight loop over using aset?
11:31	durka42	is it an array of primitives?
11:31	dnolen	yes
11:32	Chouser	are you sure? :-)
11:32	dnolen	pretty sure
11:33	durka42	or are you giving aset-int Integers
11:33	Chouser	also, are you setting the value to an Integer or a primitive int?
11:33	dnolen	on comp.lang.lisp some time ago, there was a performance metric on the speed of array-primes in Clojure vs. SBCL.
11:33	dnolen	here let me paste and you all can see.
11:36	lisppaste8	dnolen pasted "array-primes" at http://paste.lisp.org/display/80027
11:37	dnolen	this has been tweaked a little, (hopefully I didn't mess it up) from what I saw on the mailing list.
11:38	dnolen	is it possible to get for loop performance over java primitive arrays in Clojure, or is something best done in Java?
11:38	dnolen	that's really what I think the question is here.
11:38	Chouser	you should be able to get there.
11:38	dnolen	Chouser: that's what I thought
11:38	dnolen	but I've tried a lot of things and haven't been able to figure it out.
11:38	Chouser	and loop/recur with primitives is the way to get there.
11:39	dnolen	yes
11:39	dnolen	that what's being used here
11:39	Chouser	ok, outer-index is a non-primitive
11:39	Chouser	which means inner-index is non-primitive
11:40	Chouser	which means the * operations will have to box/unbox (I think), etc.
11:40	Chouser	perhaps try (loop [outer-index (int 2)] ...) instead of the #^Integer hint?
11:40	dnolen	it said I can't type hint a local
11:41	dnolen	with primitive initializer
11:42	Chouser	,(loop [i (int 2)] (if (< i 10) (recur (unchecked-inc i)) i))
11:42	clojurebot	10
11:42	lisppaste8	dnolen pasted "aset vs. aset-in" at http://paste.lisp.org/display/80028
11:43	dnolen	here's the example of aset-int being slower than aset
11:43	dnolen	aset-int takes about 1.2s while aset takes ~120ms
11:44	stuhood	~def aset-int
11:45	stuartsierra1	For these situations, it might be useful to have a "disassemble" function that shows the generated bytecode.
11:46	dnolen	stuartsierra: true.
11:47	dnolen	,(loop [#^Integer i (int 2)] (if (< i 10) (recur (unchecked-inc i)) i))
11:47	clojurebot	java.lang.UnsupportedOperationException: Can't type hint a local with a primitive initializer
11:47	lisppaste8	rhickey annotated #80027 "faster array-primes" at http://paste.lisp.org/display/80027#1
11:49	hiredman	so unchecked-inc -> inc
11:50	rhickey	less is more, avoid unchecked if you can
11:50	durka42	(neg? (unchecked-subtract (int aidx) (int limit))) seems to be much baster than (< (int aidx) (int limit))
11:50	rhickey	coercing at point of use is always a mistake, coerce at point of binding
11:51	rhickey	i.e. let/loop
11:51	Chouser	is that why aset-inc in his second example is slower than aset?
11:53	rhickey	a trick, if you fn takes something you want to be considered primitive, re-let it: (defn integers [limit] (let [limit (int limit) ...
11:53	Chouser	I guess with a hinted array, aset is resolving a direct method-call anyway. Perhaps there's simply nothing faster than that.
11:53	rhickey	Chouser: yes, hinted array + aset is fastest, aset-int is not a fast thing at all
11:53	stuhood	Chouser: beat me to it... the array is already type hinted
11:54	stuartsierra	Does aset compile to a method call or to a bytecode array operation?
11:54	stuhood	method call: Array.setBlah
11:55	rhickey	stuartsierra: with all hints in place, the static method it resolves to is optimized by HotSpot into single array instructions, but I never have to emit them
11:55	stuartsierra	ok, cool
11:56	rhickey	stuhood: no, aset can do much better than Array.setBlah
11:56	stuhood	rhickey: after hotspot has compiled it? the implementation of aset just looks like it calls Arrays.set
11:57	rhickey	stuartsierra: that's one reason why disassembly won't show full story, but you can see what hotspot does using some flags I think
11:57	stuartsierra	ok. I was about to ask if there was a way to see what Hotspot is doing.
11:57	Chouser	so aset-<type> is for convience to avoid reflection, not performance when you're willing to type hint for primitives.
11:57	dnolen	wow
11:57	dnolen	this is great
11:57	cgrand1	stuhood: look at the :inline meta
11:58	dnolen	so array-prime minus all the aset-int cruft when from taking forever to taking 900ms
11:58	rhickey	stuhood: aset has an inline definition
11:58	dnolen	so filter is eager correct?
11:58	dnolen	not lazy.
11:58	rhickey	to RT.aset, which is overloaded for specific arrays
11:58	kotarak	dnolen: filter is lazy
11:58	stuhood	ahhh
11:59	dnolen	OK so maybe not 900ms :)
12:03	rhickey	I wrote about optimization tips here: http://groups.google.com/group/clojure/browse_frm/thread/61f236e830d98cb3/9cc8e1572b793c7e?lnk=gst&q=optimization#9cc8e1572b793c7e
12:03	rhickey	no one replied
12:03	Chouser	heh
12:05	stuartsierra	those might be good tips to add to clojure.org
12:05	dnolen	yes
12:06	stuhood	cgrand1: regarding the inline definitions: when does it have to fall back to the clojure implementation?
12:06	dnolen	Also perhaps a clarification about what aset-* does? its seems easy to get confused.
12:10	chessguy_work	a witch!!!
12:11	cgrand	stuhood: when the arity is not supported by the inline definition (here for aset, only calls to aset with 3 arguments get inlined).
12:12	hiredman	clojurebot: optimizing?
12:12	clojurebot	excusez-moi
12:12	hiredman	clojurebot: optimizing is http://groups.google.com/group/clojure/browse_frm/thread/61f236e830d98cb3/9cc8e1572b793c7e?lnk=gst&q=optimization&pli=1
12:12	clojurebot	Ik begrijp
12:13	chessguy_work	clojurebot, ptimizing?
12:13	chessguy_work	clojurebot: optimizing?
12:13	clojurebot	optimizing is http://groups.google.com/group/clojure/browse_frm/thread/61f236e830d98cb3/9cc8e1572b793c7e?lnk=gst&q=optimization&pli=1
12:14	rhickey	http://clojure.org/java_interop#optimization
12:14	Chouser	stuhood: also when getting the function as a value, like if you're passing it to 'map'
12:15	hiredman	clojurebot: forget optimizing
12:15	clojurebot	I forgot optimizing
12:15	hiredman	clojurebot: optimizing is http://clojure.org/java_interop#optimization
12:15	clojurebot	Roger.
12:17	stuhood	Chouser,cgrand: gotcha, thanks.
12:30	cads	hey, does clojure have a way to exhaustively search an infinite sequence?
12:31	hiredman	how would you do that?
12:31	hiredman	if it is an ordered infinite sequence I imagine you chould do something with take-while
12:32	hiredman	but otherwise you would just search forever
12:43	danlarkin	replaca: ping
12:48	replaca	danlarkin: pong
12:48	danlarkin	I got your github message, tried to run your clojure-json branch but I get an error on line 60 of json.clj
12:49	danlarkin	Unable to resolve symbol: write in this context
12:50	replaca	danlarkin: oops, a use but - I think I have uncommited code. One sec
12:50	replaca	*but => bug
12:52	replaca	danlarkin: sorry. Try now
12:54	replaca	danlarkin: I have too many git & svn projs going at once! All with alternate repositories and such. Gets confusing :-(.
12:54	danlarkin	replaca: agreed
12:55	danlarkin	replaca: have you run the tests? I get a stackoverflow error when it tries the big "pass1" test
12:56	replaca	danlarkin: no, I just ran it over the contrib API Index. That's just meant as a quick "concept" idea rather than finished code anyway
13:02	danlarkin	replaca: currently it's an awful lot slower than the master branch
13:02	danlarkin	500ms versus 10ms
13:02	danlarkin	microbenchmark, admittedly
13:03	danlarkin	but the proof of concept is sound
13:03	replaca	danlarkin: yeah, pretty printing has to work harder cause it's all conditional
13:04	replaca	danlarkin: but there's also lots of work that can be done to speed it up (I've just begun on that).
13:04	danlarkin	what about only running it through the pretty printer if the :indent option is passed
13:04	replaca	(by conditional I mean it will keep things on the same line when it can)
13:04	danlarkin	or some equivalent flag
13:05	replaca	as I've thought about it more, I think it makes sense to have a separate pretty printing encoder in contrib
13:06	replaca	so you'd have json.{read,write,pretty} or something like that
13:06	danlarkin	something like (contrib.prettify (contrib.json.write foo))?
13:06	replaca	cause it's a big switch
13:07	replaca	danlarkin: no, that doesn't work cause pretty printing works on s-exps, not strings
13:07	replaca	so it can't happen on the output
13:07	danlarkin	:-/
13:08	replaca	rather, it's thinking about the data structure as it's constructing the output to decide where
13:08	replaca	line breaks and indents go
13:08	danlarkin	so you're trying to pass the indenting that the pretty printer gives you on through the encoder function?
13:08	replaca	no, the pretty printer is the encoder function
13:09	danlarkin	is it not possible to make the pretty printer deal with strings? or is that just too much of a different job
13:09	replaca	basically it's a recursive dispatch mechanism
13:09	danlarkin	oh, right
13:09	replaca	completely different job & then you need a parser
13:10	replaca	the pretty printer (like lots of lisp stuff) operates on structure
13:10	replaca	but dispatch means you can get any kind of structure out
13:10	danlarkin	mmmhmm
13:11	replaca	The big advantage is that it's easy for it to be very smart about when and where to put line breaks
13:11	tbb	hi all, i have a problem i hope someone can help me with. i'm writing some sort of algorithmic animation tool. i define some algorithms that change the visuals over time. i'd also like to add some algorithms together in another algorithm. whenever these algorithms are called, i want it to show in the logs, but.. i want to know whether the lowlevel algorithm calls belong to the highlevel call or whether they are separate calls. i defined the followin
13:11	tbb	(def action-id nil)
13:11	tbb	(defn action-id []
13:11	tbb	(if (nil? action-id)
13:11	tbb	(gensym "action-")
13:11	tbb	action-id))
13:11	tbb	(defn action-id-test []
13:11	replaca	so it doesn't put a whole bunch of unnecessary line breaks in
13:11	tbb	(println (action-id))
13:11	tbb	(loop [counter 0]
13:11	tbb	(binding [action-id (action-id)]
13:11	tbb	(println (action-id))
13:11	tbb	(println counter)
13:11	tbb	(if (> counter 5)
13:11	tbb	nil
13:12	tbb	(recur (inc counter))))))
13:12	tbb	oops
13:12	danlarkin	tbb: please do not spam the channel with code, that's incredibly rude
13:12	tbb	my problem is: the binding gets cached somehow
13:12	tbb	i'm sorry
13:12	danlarkin	replaca: brb
13:12	replaca	tbb: you can use lisppaste
13:12	tbb	i thought it would show up nicer
13:12	replaca	danlarkin: gotta run to the office
13:12	replaca	lisppaste8: url?
13:12	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
13:12	danlarkin	replaca: we'll talk later, then
13:13	replaca	ok, sounds good. I'll fix that bug somewhere along the way
13:13	tbb	past number 80033, the problem is the binding gets cached
13:14	tbb	the weird thing is that it is cached in the repl, but not c-x c-e in the file
13:14	lisppaste8	tbb pasted "cached-binding" at http://paste.lisp.org/display/80034
13:15	tbb	sorry for the spamming, i like this lisppaste :)
13:16	replaca	tbb: what do you mean by "cached?"
13:17	tbb	replaca: when i evaluate action-id in the repl it has the value of the gensym, which should be rebound to nil (right?)
13:20	tbb	without the recursion it works properly
13:22	lisppaste8	hiredman annotated #80034 "output at repl" at http://paste.lisp.org/display/80034#1
13:23	hiredman	I dunno why you would put the binding in the loop like that anyway
13:23	lisppaste8	tbb pasted "first-run-second-run" at http://paste.lisp.org/display/80036
13:23	hiredman	I would definetly put it outside the loop
13:25	tbb	hiredman: this is just a test to see if the bindings worked, i'll be using this in different algorithms, compounded algorithms should all log with the same id
13:25	tbb	i'll make an example
13:25	replaca	hiredman: well, if he wants a different binding for each recursion step (I assume this is a simplified example)
13:25	replaca	*fdr => for
13:25	hiredman	tbb: the problem is the extra println at the top of the function
13:25	hiredman	it is making you think something is happen, which isn't
13:26	hiredman	binding definetly works
13:26	hiredman	but keep in mind binding is not assignment
13:26	tbb	hiredman: what do you get if you evaluate action-id in the repl now?
13:26	replaca	tbb: but afterwards, what does the repl think the value of action-id is?
13:27	replaca	hiredman: tbb think the binding is "sticky" all the way back to the repl
13:27	replaca	tbb: right?
13:27	tbb	replaca: it thinks it's "action-id-###", it doesn't return to nil
13:27	tbb	yes
13:27	tbb	this is the output of two consequent runs: lisppaste8: tbb pasted "first-run-second-run" at http://paste.lisp.org/display/80036
13:27	replaca	tbb: that seems wrong to me, too
13:28	hiredman	tbb: you should lookup gensym
13:28	hiredman	~def gensym
13:28	replaca	hiredman: I don't think tbb is talking about the gensym
13:29	replaca	hiredman: the fact that it has two differnt vals is OK
13:29	tbb	i'll make a clearer example
13:29	replaca	tbb: when you use lisppaste, just keep annotating the same paste rather than creating new ones
13:29	tbb	ok
13:30	lisppaste8	tbb annotated #80036 "clear-example" at http://paste.lisp.org/display/80036#1
13:30	replaca	means I can type ^r inmy browser :-)
13:30	tbb	haha
13:31	tbb	somehow, the recursion makes it sticky
13:32	replaca	tbb: I agree that action-id should be nil after that, but maybe there's something I don't understand about binding here
13:32	replaca	tbb: Maybe a group post would shed more light on this
13:32	tbb	replaca: i'm coding an example of how i intend to use it
13:33	tbb	i'll do that
13:33	replaca	tbb: I've got to run, but I'm also interested in the answer here cause I would think that the result you're getting is impossible. But clearly, we're both wrong :-)
13:34	tbb	haha, ok, i'll post it to the group
13:34	tbb	thanks for your time :)
13:34	replaca	tb: no prob
13:35	hiredman	hmmm
13:36	hiredman	it looks like the bindings are not being removed
13:36	tbb	what i've found out is they are removed if there aren't any recursive bindings, and it only happens in the repl
13:36	lisppaste8	hiredman annotated #80034 "set!" at http://paste.lisp.org/display/80034#2
13:37	tbb	hiredman: yes, that's what i get too
13:39	lisppaste8	hiredman annotated #80034 "close the binding before recur" at http://paste.lisp.org/display/80034#3
13:40	hiredman	that gives what I assume is the expected behaviour
13:43	tbb	hiredman: the intended behavior is that action-id is bound to a gensym and stays bound to it all the way down the function calls, it should only be bound at the toplevel
13:43	tbb	so the every time i call action-id-test the gensym should be the same for all the print outs, but the next time i call it they should be different than before
13:44	hiredman	ah
13:44	hiredman	hmm
13:47	lisppaste8	hiredman annotated #80034 "binding outside the loop" at http://paste.lisp.org/display/80034#4
13:48	tbb	hiredman: it seems like loop is the culprit indeed
13:48	hiredman	yeah
13:48	tbb	although in this way i can't test the recursiveness i'm after
13:49	tbb	i made a new example that shows the intended use
13:49	cp2	hello folks
13:50	lisppaste8	tbb annotated #80034 "intended" at http://paste.lisp.org/display/80034#5
13:50	tbb	hi cp2
13:51	tbb	hiredman: that one works just fine
13:51	hiredman	tbb: I don't see anything that precludes the use of binding outside the loop
13:52	hiredman	it is troubling none the less
13:52	tbb	hiredman: i used it inside the loop to simulate functions calls that all rebind action-id, like in the new annotation
13:52	hiredman	you are sending something to the group?
13:53	tbb	it seems to work for what i wanted to use it for, but i'd like to know why we get this behavior so i'll post something
13:54	hiredman	ugh
13:54	hiredman	writing guis is such a drag (everywhere) I wish someone would do something about that
13:55	slashus2	Make a DSL for GUI programming?
13:55	technomancy	stop using GUIs? =)
13:55	dnolen___	hiredman: I'd say Cocoa + Interface Builder is damn good. sad so few GUI programming systems have learned from it.
13:55	hiredman	technomancy: Word
13:56	dnolen___	Interface Builder was originally a Lisp program.
13:58	chrizel	There should be a functional way of making GUIs... :-/
13:58	hiredman	there are
13:59	hiredman	~google functional reactive programing
13:59	clojurebot	First, out of 46000 results is:
13:59	clojurebot	Functional reactive programming - Wikipedia, the free encyclopedia
13:59	clojurebot	http://en.wikipedia.org/wiki/Functional_reactive_programming
14:03	dnolen___	http://www.cs.virginia.edu/~robins/papers/Signal_Constellation_Design_Tool_A_Case_Study_in_User_Interface_Synthesis.pdf
14:03	dnolen___	history of original Interface Builder as Lisp program running on Macintosh
14:03	rfgpfeiffer	is there a continuation-based web framework for Clojure?
14:04	hiredman	nope
14:04	dnolen___	rfgpfeiffer: I'm still working on it
14:04	dnolen___	but not a whole framework
14:04	dnolen___	just middleware
14:04	dnolen___	then you can use whatever webframework you want.
14:04	stuartsierra	The JVM cannot support continuations natively.
14:04	dnolen___	you don't need to support full continuations for building webapps tho.
14:04	dnolen___	just delimited continuations, this what Seaside and Weblocks use.
14:04	stuartsierra	yes
14:05	stuartsierra	Right, you can simulate continuations up to a point.
14:05	rhickey	stuartsierra: sorry I can't make it tomorrow - conflict w/school band concert!
14:05	dnolen___	stuartsierra: yeah, you only need to capture use interactions, not the whole state of the web stack.
14:05	dnolen___	user interactions.
14:06	rfgpfeiffer	http://github.com/nex3/arc/blob/b3d2199f52fc0ef96ae78656e5baff0b18cb6cf3/srv.arc only uses closures
14:06	stuartsierra	rhickey: that's ok. We're still sketchy on the venue anyway.
14:06	rhickey	stuartsierra: I wonder what the attendance might be for a NYC Clojure meetup group
14:07	hiredman	rhickey: did you see tbb's issue with binding and recur?
14:07	danlarkin	re: NYC meetup: on the right day I would go
14:08	stuartsierra	rhickey: I've wondered the same thing
14:23	tbb	hiredman: i just posted it to the group :)
14:26	hiredman	tbb: is this your first post?
14:26	tbb	yes
14:27	hiredman	ok, so it will sit in the moderation queue until rhickey gives it the go ahead
14:27	tbb	ah, i see
14:28	tbb	well, i'm not in a hurry :)
14:28	tbb	thanks for your time man
14:40	stuartsierra	and I'm back
14:50	mattrepl	wb
14:51	rhickey	stuartsierra: any thoughts on a meeting place?
14:57	stuartsierra	rhickey: Hmm. Columbia's too expensive, unless I can a group will sponsor it.
14:58	stuartsierra	Let me think about it. Got to prepare for LispNYC tomorrow and an exam on Wednesday.
14:58	rhickey	stuartsierra: I guess that's why lispnyc meets in churches and bars :)
14:58	stuartsierra	rhickey: exactly.
15:01	smauel	hey guys so when is the 'programming clojure' book coming out?
15:02	cp2	how about a clojure meet in dc
15:02	rhickey	cp2: http://groups.google.com/group/clojure-study-dc
15:02	cp2	oh neat
15:03	smauel	anyone know?
15:03	stuartsierra	smauel: soon :)
15:04	stuartsierra	You can get the PDF now.
15:04	smauel	ya but it's delayed isn't it?
15:04	smauel	it was meant to be out on the 28th april
15:04	stuartsierra	yes, it was delayed for the lazy sequence branch of Clojure, completed now
15:05	Chouser	yeah, someone changed the language.
15:05	cp2	those bastards =p
15:05	sdf	d
15:05	smauel`	sorry i dc
15:16	replaca	stuartsierra, rhickey: Can you do what we do here in SF? Find a friendly company with a big conference room.
15:17	rhickey	replaca: maybe, stuartsierra said he'd think on it
15:18	grzm	I think I'm misunderstanding the use of (ns com.example.foo (:use (com.example [bar :as bar])))
15:18	replaca	I mean, Lisp is a religion, but actually going to church seems a bit much :-)
15:18	stuartsierra	heh
15:19	rhickey	I've given a few talks at that church - it's very bizarre
15:19	grzm	I was thinking that I would need to refer to all of the com.example.bar objects using bar/some-bar-obj, but it seems like some-bar-obj works just fine by itself.
15:19	hiredman	grzm: replace :user with :require
15:19	hiredman	er
15:19	hiredman	:user
15:19	hiredman	:use
15:19	hiredman	blah
15:19	Chouser	or add :only []
15:20	grzm	hiredman: thanks for confirming
15:20	grzm	Chouser: I actually want the shortened namespace scoping as I have objects with the same names in different namespaces, so if I'm understanding correctly, I'd still get collisions with :only
15:21	rhickey	What's up with Scandinavia? Is there a big Clojure base there? I've been invited to speak at 3 separate conferences in Denmark, Norway and Sweden
15:21	stuartsierra	Maybe it's all those mobile phone folk.
15:22	stuartsierra	Ask them when I can get a Lisphone.
15:22	Chouser	grzm: by default, 'use' will bring all the names into your new namespace. but if you say :only, then it will bring in just the ones you specify
15:23	Chouser	grzm: so :only [] will bring in none -- just like 'require' does by default.
15:23	rhickey	stuartsierra: as soon as we get Clojure compiling to ObjectiveC
15:23	grzm	Chouser: thanks for confirming
15:23	stuartsierra	ObjectiveC, really? Oh, the iPhone, right.
15:23	grzm	oh, I see: you meant explicitly an empty array
15:23	Chouser	grzm: yes
15:23	Chouser	empty vector
15:24	grzm	Chouser: vector :) cheers
15:24	cp2	rhickey: er.. really?
15:25	cp2	oh i see, didnt notice what stuartsierra said
15:25	rhickey	stuartsierra: on android already
15:25	Chouser	refcount instead of garbage collection (for ObjectiveC)?
15:26	rhickey	Chouser: that is the problem, even though Objc 2 has GC, iPhone doesn't?
15:26	dnolen	ObjC has garbage collection now, just not on phone. Probably a matter of time tho. There is a usable Lisp for iPhone Dev, Nu, but it's not nearly as nice as Clojure.
15:26	cemerick	is it realistic to think that clojure will eventually have more (full-featured) backends beyond the jvm and clr? Getting to the point where 90% is self-hosting obviously simplifies things, but that last 10% (concurrency primitives, memory model, etc) get really tricky on other signficantly-different platforms (objc, llvm, etc?)
15:26	Chouser	rhickey: so someone said.
15:26	cp2	how is clojure on clr doing anyway?
15:27	Chouser	cemerick: but looking at contrib, for example, may demonstrate how little that 10% is required for some large set of apps.
15:27	rhickey	cemerick: I'm not sure any would be 'full-featured' other than jvm/clr, but those are two huge targets. Still plenty of utility in partially-featured JS/ActionScript/ObjC, IMO
15:27	stuartsierra	agreed
15:28	dnolen	btw, if a Clojure NYC user group happens, I host a small study group in Brooklyn that would definitely be interested in coming.
15:29	stuartsierra	It will happen. How does mid-June sound?
15:29	dnolen	great
15:29	rhickey	Chouser: I got sidetracked a bit with this modularity stuff (it's a big deal for Netbeans/OSGi et al), because it looks like I can deliver some benefit pre-clojure-on-clojure. Then I'm onto c-i-c
15:30	replaca	rhickey: have you thought about Blackberry at all? I know it's mostly J2ME which I remember being an issue for Clojure. I have a good friend who's an evangelist there and could help us make that happen if it made sense.
15:30	rhickey	stuartsierra: sounds good, just as long as post-JavaOne
15:30	stuartsierra	ok
15:30	Chouser	rhickey: ok. I've been sidetracked by a new job and lack of non-work computer to do any side projects.
15:31	Chouser	I haven't touched c-i-c in weeks, probably not since ILC
15:31	rhickey	replaca: I'm not going to go crazy trying to fit Clojure on very small profile Java, but plans include splitting out ASM and compiler stuff for smaller footprint, as well as options to drop docstrings etc
15:32	rhickey	Chouser: I have thought about it a lot, mostly making a huge list of things it needs to address :(
15:33	Chouser	nice
15:33	rhickey	I think I need to do instance/make whatever in Java prior to c-i-c so we have it when defining c-i-c
15:33	hiredman	j2me is horrible
15:33	hiredman	(btw)
15:33	smauel`	is clojure as fast as scala?
15:33	replaca	rhickey: makes sense. I think they're moving towards a biger footprint (to compete with iphone). Are there particular things we would need from them for it to make sense?
15:34	rhickey	replaca: the closer it is to j2se the better, more memory is always good too
15:36	hiredman	j2me is java 2, which is jdk 1.4 which is pre-Collections
15:36	dnolen	smauel: probably depends on what you are doing, both compile to bytecode so perf is probably comparable.
15:36	hiredman	wiat
15:36	rhickey	Chouser: I also had ideas about HIP (host-in-parens), basically a completely transparent non-abstracted DSL for generating host code, but homoiconic and thus allowing for macros. I don't like what gen-class is growing towards
15:36	hiredman	I lie
15:36	replaca	rhickey: are there any specific things along that continuum that I should probe for? I can do some reconnaissance and report back.
15:37	hiredman	jdk 1.4 has Collections
15:37	stuartsierra	host-in-parens sounds awesome
15:38	rhickey	stuartsierra: yeah the idea is that clojure in clojure would be 90% clojure, 10% host in parens, and host-in-parens would reduce pressure to cram every host feature into some Clojure feature
15:38	Chouser	huh
15:38	stuartsierra	So, in theory, you could emit x86 assembly if you wanted to?
15:39	Chouser	once you had written HIP-for-x86-assembly
15:39	stuartsierra	right
15:39	rhickey	by the time we add all access specifiers, package qualifiers, annotations etc into gen-class, I'd rather write Java
15:40	stuartsierra	yeah, that makes sense
15:40	rhickey	erm, I don't think assembly is going to be a viable host. We're still talking simple-object-based hosts
15:40	stuartsierra	fair enough
15:41	stuartsierra	That still leaves a lot of options. JVM, CLR, Parrot, ...?
15:41	Chouser	did anyone see my little JNA bit? Makes C look more dynamic that I would have guessed.
15:41	Chouser	than
15:41	dnolen	rhickey: this would grealy simplify getting Clojure subset to run ObjC? ... that would be sweet.
15:41	duncanm	Chouser: link?
15:41	Chouser	http://github.com/Chouser/clojure-jna/tree/master
15:42	cp2	Chouser: yeah, jna is pretty nice
15:42	cp2	oh, clojure jna
15:42	cp2	havent seen that ye
15:42	cp2	t.
15:42	rhickey	dnolen: I don't know enough about ObjC to say definitively. I'd love to target the iPhone, but don't know if lack of GC is prohibitive. Everything else has GC
15:42	cp2	looks good
15:42	Chouser	It's hardly anything but it's fun. With no other in-clojure setup or declarations: (jna-invoke Integer c/printf "My number: %d\n" 5)
15:43	rhickey	ah, printf
15:43	rhickey	been a while
15:43	Chouser	right, because that's what you really want from libc
15:43	Chouser	:-)
15:43	cp2	heh
15:43	cp2	I guess it's the number of bytes printed or
15:43	cp2	something? Anyway, feel free to ignore it just like all C programs do.
15:43	cp2	i chuckled
15:44	Chouser	I'm hoping this will be the solution to my dbus-java pain.
15:44	Chousuke	I didn't even realise printf had a return value
15:44	sohail	Chouser, that is effing hardcore man :-)
15:44	Chousuke	I'm sure I've read the manual page more than once.
15:44	cp2	yeah i didnt know that either
15:44	cp2	learn something new everyday =)
15:45	cp2	oh, jna-fn is nice
15:45	Chouser	yeah, I think many C programmers would be startled by: int i = printf(...)
15:46	sohail	I thought printf returns int... why is that startling?
15:47	danlarkin	ah university programming, where they made us check the return value of printf
15:48	cp2	seriously? uck
15:48	cp2	if (!printf(....)) printf("error printing\n");
15:48	cp2	oh wait...
15:48	danlarkin	yeah it was all if(printf("foo") > 0) style
15:49	Chouser	if printf didn't segfault, that sounds like success to me
15:49	rhickey	there you go
15:49	danlarkin	not so much with printf, but with sprintf it's useful
15:49	Chouser	That's the other thing you realize using jna, esp. with strings. One little misstep and down goes the JVM.
15:50	cp2	well, jna automagically converts java String to c style strings
15:50	cp2	so shouldnt be too problematic
15:50	Chouser	(c-printf "My number: %s\n" 5)
15:50	Chouser	boom
15:50	hiredman	ouch
15:51	rhickey	Chouser: that was my problem with jFli (embedding JVM in CL), one interop problem and the JVM goes down, taking CL with it or at least rendering the JVM non-restartable
15:51	cp2	oh right Chouser
15:51	stuartsierra	wew
15:51	Chouser	rhickey: you had to do JNI stuff to get the two to talk?
15:51	stuartsierra	wow
15:51	rhickey	Chouser: big time JNI
15:51	cp2	yeah
15:52	rhickey	not fun
15:52	cp2	jni is disgusting =p
15:52	rhickey	but it was a one-time thing, once jFli was working you could new up and call Java objects as if they were CLOS objects
15:52	Chouser	jna is about as pretty as one could hope for.
15:53	Chouser	rhickey: well, no offense, but I'm glad you gave up on it.
15:53	rhickey	That's the biggest relief with Clojure, the host/implementation lang and Clojure share GC/memory model/ type system etc. interop is perilous
15:54	rhickey	Chouser: me too :)
15:54	drewr	rhickey: How reluctant were you at first to create a new lisp dialect? Was it a last resort?
15:55	rhickey	OTOH, it works - Nick Levine polished up jFli a bit subsequently and its perfectly useable
15:57	rhickey	drewr: when I first learned CL after a dozen years of C++ I thought, "WT heck have I been doing with my life!? I want to eventually program like this (Lisp)". Only with Clojure does that now seem possible.
15:58	dnolen	:)
15:58	stuartsierra	"Clojure: Lisp for people who need to get s*** done."
15:58	rhickey	exactly
15:58	drewr	rhickey: I mean, was creating a separate lisp ever a definite "no" in your mind, an end you eventually had to compromise with?
15:58	clojurebot	rhickey is a T-1000 sent from the future
15:59	rhickey	though I'd prefer an expletive-free slogan :)
15:59	dnolen	at my study group the other day we were talking about the insanity of C++ const, and how you can avoid that alltogether if everything is immutable by default.
15:59	hiredman	~optimizing
15:59	clojurebot	optimizing is http://clojure.org/java_interop#optimization
15:59	drewr	I'm guessing the answer is yes since you tried everything else first, but I didn't know how reluctant you were.
16:00	rhickey	drewr: creating a new language is a crazy thing to do. The only reason I did that, rather than keep pursuing interop or move to ABCL/Kawa was I had some new ideas about mixing Lisp and FP
16:00	stuartsierra	rhickey: Yeah, might not sit too well for the corporate folks. But the college kids will like it.
16:01	technomancy	clojurebot: optimazating is http://wondermark.com/481/
16:01	clojurebot	Alles klar
16:03	rhickey	stuartsierra: after the "Ruby: Perform Like a Pr0n Star" slides scandal, I think Clojure should stay on the high road
16:03	drewr	lol
16:03	technomancy	there could be ladies present
16:03	Chouser	or gentlemen
16:04	technomancy	that too. =)
16:04	stuartsierra	Well, if you insist. :)
16:05	stuartsierra	"Clojure: Lisp without Weenies."
16:08	Raynes	"Clojure: Lisp of the Rings."
16:08	sohail	I thought pr0n stars only fake performance by doing the same scenes over and over to make it look longer
16:09	dmiles	btw: clojure on IKVM is pretty cool
16:09	stuartsierra	Yes, but we call it recursion.
16:09	dmiles	haha
16:09	sohail	ruby doesn't support tail recursion!
16:09	sohail	ok I'm done
16:10	dmiles	As far as introp with ABCL.Net.Dll its going to take more work.. almost better maybe if i have the interop in Java first
16:10	sohail	tail call optimization, now I'm done
16:11	rhickey	uh oh, time to switch to Axum: http://msdn.microsoft.com/en-us/devlabs/dd795202.aspx
16:11	rhickey	says MS
16:12	Chouser	"builds upon the architecture of the Web"!?
16:12	Raynes	Axum looks infinitely boring.
16:12	technomancy	"Should I Use Axum? Yes!" <= well, I guess that settles it then.
16:12	ataggart	lol
16:13	ataggart	the hivemind has spoken
16:13	hiredman	I opened the programmer's guide, saw the visual studio "create a new project" stuff, and ran away
16:14	Chouser	hiredman: I just did the same thing.
16:14	technomancy	hiredman: maybe if you installed the Silverlight plugin you could be wowed by the video.
16:14	Chouser	The Basics ... screenshot ... close pdf viewer.
16:14	hiredman	technomancy: possibly
16:14	Chouser	But then again, I'm probably being closed-minded.
16:16	Chouser	It's so much easier to dismiss a new language than to expend the effort to find out if it has anything worth learning about.
16:16	Chousuke	it kind of looks like it's C# with new keywords and syntactic sugar
16:17	hiredman	Chouser: exactly
16:18	Chousuke	pity the lesser languages.. if you want syntactic sugar all you can do is invent a new language ;(
16:19	technomancy	Raynes: does it say it works on Mono? IronRuby doesn't.
16:19	Raynes	technomancy: No, I just don't feel like installing Mono. For any of those Microsoft languages.
16:22	edgar_	hello
16:23	edgar_	i got clojure
16:23	edgar_	but when i try to run it, i got an error
16:23	Chouser	edgar_: you downloaded the 1.0.0 zip file?
16:23	edgar_	i'm going to publish the error in pastebin.com
16:23	edgar_	for you can see it
16:23	edgar_	Chouser yes
16:23	edgar_	<Chouser>
16:24	hiredman	...
16:24	Chouser	hiredman: you spilled some dots
16:24	Raynes	...
16:24	edgar_	http://pastebin.com/d446275a2
16:25	hiredman	edgar_: replace clojure.lang.Repl with clojure.main
16:25	edgar_	there is the pastebin link where is the error i got
16:25	edgar_	ok let me see
16:25	stuhood	or run `java -jar clojure.jar`
16:25	hiredman	that too
16:25	edgar_	well i got a similar error
16:27	edgar_	okok, now it runs with java -jar clojure.jar
16:28	edgar_	i got other problem with the clojure netbeans plugin
16:28	edgar_	i installed but it wont create a clojure project
16:28	edgar_	it seems that is in development
16:29	edgar_	and also i have netbeans 6.7 beta, so maybe isn't compatible
16:30	replaca	the axum guys lost me at "start Visual Studio...."
16:31	chrizel	is there an apply for methods? like (apply method-name object args)?
16:31	replaca	I see hiredman had the same reaction
16:31	Chouser	chrizel: the method takes varargs?
16:31	hiredman	edgar_: I do not believe there are too many netbeans users here, maybe Raynes can help?
16:32	Chouser	chrizel: or you just want to unpack a fixed number of args from a seq?
16:32	Raynes	I certainly can. NetBeans 6.7 is currently not supported.
16:32	Raynes	You'll have to use 6.5 for now.
16:32	edgar_	so you are saying that netbeans isn't used by many users?
16:32	chrizel	Chouser, a fixed number of args i get from an vector - ok, then i could just unpack them before...
16:33	Chouser	chrizel: yeah, you can either use a macro, or just (.foo obj (v 0) (v 1) (v 2))
16:33	hiredman	edgar_: as far as this this channel goes the only one I know of off the top of my head is Raynes
16:33	Raynes	edgar_: Most people just use Emacs. The NetBean's plugin is pretty good, I switched to Eclipse simply because I use it more. Both plugins will improve in the future. They are quite new.
16:33	hiredman	I dunno about the community at large
16:34	edgar_	ok
16:34	Raynes	Well, /they work/. That's all I can promise. ;)
16:34	chrizel	Chouser, thx
16:34	edgar_	and so...most of the people prefer emacs over vim?
16:35	cads	hiredman: I think we can search certain classes of compact uncountable spaces in finite time. http://www.cs.bham.ac.uk/~mhe/papers/exhaustive.pdf
16:35	stuhood	Chouser, chrizel: this might be a usecase for 'memfn': (apply (memfn method-name) obj args)
16:35	hiredman	I use vim
16:36	stuhood	oh, no, nvm.
16:36	edgar_	maybe in the future we see other kind of plugin for vim
16:36	hiredman	~vimclojure
16:36	clojurebot	vimclojure is state-of-the-art
16:37	hiredman	wow, that was not so useful
16:37	hiredman	~google vimclojure
16:37	clojurebot	First, out of 131 results is:
16:37	clojurebot	Kotka : Projects : Clojure : VimClojure
16:37	clojurebot	http://kotka.de/projects/clojure/vimclojure.html
16:37	chrizel	stuhood, oh thanks, i'll try
16:38	hiredman	edgar_: vimclojure is pretty nice, I have some issues with it's more advanced features, but most vimers find it acceptable
16:38	edgar_	ok
16:38	stuhood	chrizel: that code won't work directly, but i think it is a start... still trying to figure it out
16:38	hiredman	~VIM
16:38	clojurebot	excusez-moi
16:38	hiredman	~vim
16:38	clojurebot	Gesundheit!
16:39	hiredman	hmm
16:39	kotarak	Even without the advanced features <C-n> eg. should get you quite far.
16:39	kotarak	The advanced features need introspection of Clojure. That implies certain constraints on the way the source looks like.
16:39	hiredman	I honestly never remember the shortcuts, so I just live with identing and highlighting
16:40	kotarak	hiredman: me too :) I'm getting used to <C-n> and <C-x><C-o> only slowly.
16:40	hiredman	huh
16:40	hiredman	tab seems to do the same thing as <C-n> for me
16:40	hiredman	I wonder's whose .vimrc I picked that up from
16:41	kotarak	hiredman: maybe the supertab plugin?
16:41	cads	hiredman, I don't think I can understand the topology and computability theory behind it, but the guy wrote a haskell monad that lets you define and search infinite yet exhaustible sets
16:42	hiredman	ah
16:42	hiredman	well those are not sequences :P
16:42	hiredman	?
16:43	cads	yeah, sequences have an order topology that makes them inexhaustible I guess :)
16:43	hiredman	I imagine that would use specific knowledge in the domain of sets
16:44	cads	I'm going to see if can write the cantor set search function in clojure
16:44	cads	I have to say the haskell version looks spiffy: http://math.andrej.com/2008/11/21/a-haskell-monad-for-infinite-search-in-finite-time/
16:44	stuhood	chrizel: it looks like memfn requires you to name all the arguments you'll be passing, but if that works for you, it will generate a function that you can apply to: (apply (memfn split sep) ["blah" "a"])
16:44	cads	apparently, a few of the functions can be generated for free just from their type specification
16:47	hiredman	,^#'+
16:47	clojurebot	{:ns #<Namespace clojure.core>, :name +, :file "clojure/core.clj", :line 569, :arglists ([] [x] [x y] [x y & more]), :inline-arities #{2}, :inline #<core$fn__3327 clojure.core$fn__3327@189fe1e>, :doc "Returns the sum of nums. (+) returns 0."}
16:49	chrizel	stuhood, i did it with let and destructuring, but good to know about memfn, could be useful sometime
16:50	stuhood	chrizel: yea... memfn just expands into a (let) wrapped in a (fn)
16:54	kotarak	technomancy: it should return a full path for a file read with load-file, no?
16:55	technomancy	kotarak: maybe... I haven't used load-file in months
16:55	kotarak	me neither...
16:55	technomancy	it's not much good if it doesn't return consistent results
16:55	hiredman	technomancy: well java sort of ignores the filesystem outside of jars files and the classpath
16:59	technomancy	quite a shame
17:00	technomancy	there's no problem with binding vars outside the current namespace, right?
17:01	Chouser	using 'binding'? should just work.
17:02	hiredman	it makes sense if you think of the jvm as vm
17:02	hiredman	as a
17:04	hiredman	it is some what analogous to how I have heard old ur-unix hackers talk about the unix vm
17:17	technomancy	I can't def in clojurebot, can I?
17:18	hiredman	nope
17:18	technomancy	oh bugger. a lazy seq inside a binding will get realized after it exits the binding.
17:18	technomancy	gah!
17:18	hiredman	yep
17:19	stuhood	unless you use (doall)
18:23	AWizzArd	Did anyone else also get this invitation email for a "facevibe" project?
18:25	AWizzArd	is that some modern kind of spam email?
18:26	hiredman	sounds like spam
18:27	ataggart	~optimizing
18:27	clojurebot	optimizing is http://clojure.org/java_interop#optimization
18:29	AWizzArd	someone got my email address from the google groups and told me he wants to start a new project and is looking for others to join it
18:29	AWizzArd	But the interesting part is that he says hello to me with my real name, he talks about Clojure and Compojure
18:29	AWizzArd	but the mail very much looks like spam
18:29	hiredman	it might not be spam spam
18:30	hiredman	it might just be some random guy out to change the world and show everyone how wrong they are
18:30	AWizzArd	and the website he linked to looks empty to me
18:30	technomancy	well a smart way to get stuff by spam filters is to grab keywords from publicly available mailing lists in an effort to look legitimate
18:31	AWizzArd	technomancy: yes, maybe a bot with some human input
18:31	AWizzArd	I don't want to post the link here, but maybe someone can check if the page is empty?
18:31	technomancy	AWizzArd: adblock?
18:31	AWizzArd	hiredman: you want to take a look? :)
18:31	technomancy	you could curl it
18:32	AWizzArd	technomancy: I turned that on yes, but I expect that if someone invites me to a project, there will be something visible
18:32	hiredman	AWizzArd: my curiosity is piqued
18:53	AWizzArd	wb chessguy
18:53	chessguy	why thanky
18:53	AWizzArd	maybe you can give hiredman an api, so he can make Clojurebot play chess using your engine? :p
18:54	chessguy	hmm
18:55	Raynes	"honestly? i would rather date a girl who uses heroin than a girl who uses emacs"
18:56	hiredman	clojurebot: e4 is <reply>I resign
18:56	clojurebot	Alles klar
18:56	hiredman	clojurebot: pawn to e4!
18:56	clojurebot	I resign
18:56	hiredman	there, it plays chess
18:57	AWizzArd	now it can even play chess!
19:01	dysinger	heh
19:01	dysinger	Raynes das funny
19:01	Raynes	dysinger: BONUS from #Haskell twittered that a moment ago.
19:02	dysinger	I would rather lick the bathroom clean than use VIM
19:28	dnolen	technomancy: how far is the clojure httpclient along, are you planning on using this with couchdb?
19:29	technomancy	dnolen: it's pretty usable at this point.
19:29	technomancy	I've used it with couch; it seems to be pretty straightforward.
19:29	dnolen	nice!
19:31	technomancy	dnolen: it could be more performant if it used keepalive connections
19:31	technomancy	I think that's the only significant thing left, unless others can think of any further enhancements.
19:31	dnolen	is keepalive difficult?
19:31	technomancy	not sure. =)
19:32	dnolen	:)
19:35	unlink1	Is there a more elegant way of expressing (concat (when x (list x)) coll) ?
19:37	cmvkk	to remove false values from a collection, you mean?
19:37	cmvkk	er, wait
19:38	cmvkk	you want to add x to the beginning but only if it isn't false
19:41	unlink1	I guess something like (defmacro cons-when [x xs] (let [tmp# x] (concat (when tmp# (list tmp#)) xs)))
19:42	unlink1	I mean, (defmacro cons-when [x xs] `(let [tmp# ~x] (concat (when tmp# (list tmp#)) ~xs))
19:42	clojurebot	x is y
19:42	cmvkk	yeah. although for the record, concat isn't exactly cons.
19:42	unlink1	no, but I'm logically consing.
19:46	unlink1	It could be implemented with cons. (defmacro cons-when [x xs] `(let [first# ~x rest# ~xs] (if first# (cons first# rest#) rest#)))
19:46	cmvkk	it's probably more efficient that way.
19:47	unlink1	Well whatever the implementation, I'm sure I'm not the first person to have the idea.
19:48	cmvkk	if you didn't care until the end, you could always just cons everything and then do (filter identity coll) afterwards.
19:49	cmvkk	probably not faster but maybe shorter
19:56	unlink1	Is this a correct/idiomatic implementation? (defmacro cons-when [x xs] `(let [first# ~x rest# ~xs] (if first# (cons first# rest#) rest#)))
21:55	chessguy	sure got quiet in here
22:51	eyeris	How can I instantiate an array of Java objects from Clojure?
22:53	eyeris	I want to use the Gtk java bindings, but the ListStore class requires a DataColumn[].
22:54	eyeris	Ahh, nevermind, I see (to-array coll) on the java_interop page.
22:54	danlarkin	eyeris: there's a few ways to create arrays, make-array being another
23:09	jmaness	does anyone know if there is an easy way to partition a collection based on a function?
23:10	Chouser	is the collection in order -- split it once? or collect things from where-ever into two groups?
23:10	durka42	there is partition-by
23:11	jmaness	ah thanks
23:11	jmaness	the collection isn't in order but partition-by in contrib looks like it will work
23:11	Chouser	good