#clojure – 2010-12-31

2010-12-31

00:20	amalloy	Berengal: hey, are you on the xkcd forums? i don't read them often, but i happened across a Berengal just now recommending shell scripting
00:21	Berengal	amalloy: Yeah, that's me
00:21	tanuki	Should I get "Clojure in Action" or "The Joy of Clojure"?
00:27	amalloy	tanuki: depends what you want, i'm sure. i don't know who wrote CiA, but if you get JoC you can hassle the author in #clojure
00:28	tanuki	They cancelled "F# in Action", so I'm considering getting a Clojure book instead
00:28	tanuki	(I like Lisp syntax more than ML syntax anyway)
00:33	technomancy	get the Joy of Clojure
00:35	tanuki	which is why I leaned toward F# at first
00:37	qbg	Getting closer towards a release of my syntax-rules lib
00:42	qbg	Parsing the macro usage is easy; putting together the expansion is hard
00:43	Clinteger	f#'s syntax confuses me so much
00:44	tanuki	It's not nearly as elegant as Lisp, but it's not horrible
00:44	tanuki	it's just kinda goofy at first
02:12	LauJensen	Morning :)
02:25	scottj	In case anyone's interested, Arc has this interesting (and poorly documented) feature called ssyntax, which I think stands for symbol syntax.
02:28	scottj	it allows things like (inc:dec 1) => ((comp inc dec) 1), (str a!name b!name) => (str (:name a) (:name b)), ~a => (complement a), (a.b c) => ((partial a b) c), (a&b c) => (and (a c) (b c))
02:33	LauJensen	That looks really nice
02:43	scottj	it could probably be used for evil ($pr:+.10:filter.<20?&~even?.l1!l2) :)
03:41	Derander	scottj: call it a new language: "nospace"
04:20	LauJensen	Derander: only "J" gets that title
05:10	ejackson	Good Morning #clojure, and goodbye 2010 !
05:38	LauJensen	ejackson: Goodbye!! :)
05:39	ejackson	LauJensen: you're changing you're name to 2010 ? Its a bit radical :)
06:38	fliebel	morning
06:45	ejackson	morning fliebel
07:08	maacl	LauJensen: In moustache is there a way of getting at the querystring ?
07:11	raek	maacl: accessing the query params is usually done by http://clojuredocs.org/ring/ring.middleware.params/wrap-params
07:12	raek	moustache only does four things: wrap handlers, dispatch on HTTP request URI, dispatch on HTTP method and render plain text
07:14	maacl	raek: OK, but how would I combine the two? moustache dispatch + get at the querystring when I handle the request?
07:15	raek	(app wrap-params ["foo"] {:get get-foo-handler} ["bar"] {:post post-bar-handler})
07:16	raek	(defn get-foo-handler [{:keys [params], :as request}] ...)
07:16	raek	maacl: did you want to select the handler by looking at a query parameter?
07:18	maacl	raek: yeah that was the idea
07:18	raek	moustache cannot do that, but you can very easily implement that yourself
07:20	maacl	raek: yes, thanks
07:20	raek	(defn dispatch-on-param [param handlers] (fn [{:keys [params], :as request}] (let [value (get params param), handler (get handlers value)] (handler request))))
07:21	raek	maacl: this is my idea of what it could look like
07:21	raek	calling (dispatch-on-param "foo" {"a" handler-a, "b" handler-b}) will return a handler that delegates everything to one of the given handlers
07:22	raek	(app wrap-params ["foo"] {:get (dispatch-on-param "foo" {"a" handler-a, "b" handler-b})})
07:23	maacl	raek: yeah, looks elegant - would work after having dispatched on request and method, right?
07:25	raek	yes, you can plug it in at any place the moustache syntax labels as "(some clojure code)": http://moustache.cgrand.net/syntax.html
07:28	fliebel	If I wanted to do some sort of message queue, what would I use? Lamina looks real nice, but I need something that works transparently over a network. Could I do this with Aleph, or would it be better to use a project with a name that ends in 'mq'? Lamina over *mq would be nice...
07:28	kumarshantanu	fliebel: consider using HornetQ -- it's based on Netty and exposes HTTP interface
07:29	fliebel	kumarshantanu: Thanks, will check it out.
07:31	ejackson	fliebel: I'd suggest RabbitMQ if you're being serious, and Redis (no really) if its just a toy.
07:31	ejackson	fliebel: with redis you can have something up in 10 minutes :)
07:33	fliebel	ejackson: Are you saying RabbitMQ is hard?
07:33	ejackson	fliebel: not at all, its harder than redis is all :)
07:34	ejackson	rabbitmq has exchanges and queues and stuff to wrap your head around. They have a product that can survive powerdowns and other bad stuff, so neccessarily is more complex.
07:35	ejackson	redis will give you a pubsub channel in no time but isn't going to be as robust, and I'm not sure how it handles multiple readers of a channel etc.
07:35	ejackson	check out : http://simonwillison.net/static/2010/redis-tutorial/
07:36	fliebel	ejackson: I don't know if I need al that. What I want to do is write a little game using a message system, and use the same system later for multiplayer, either local or over a network.
07:38	ejackson	redis might work for that. at any rate, its so easy to get going that you'll lose very little finding out.
07:38	ejackson	if you discover you need some clever handling of the queues, then upgrade to a proper messaging system
07:40	fliebel	ejackson: Thanks, I'll take a look at that as well.
07:40	ejackson	lemme know how you get on :)
07:40	fliebel	ejackson: I'm just in the gathering-ideas mode, so it'll brobably be a while.
07:57	bmh	What is the third argument to state-m-until?
08:01	fliebel	bmh: You could have told me it's in clojure.contrib.monads ;)
08:01	bmh	fliebel: sorry
08:02	fliebel	bmh: I don't know, but see for yourself: https://github.com/richhickey/clojure-contrib/blob/master/src/main/clojure/clojure/contrib/monads.clj#L401
08:03	bmh	ah-ha. I missed the state argument at the bottom (fn [s] ... )
09:51	duck1123	so does anyone know what I should be using for contexts in lazytest 2 now? I'd really like to find something similar to rspec's before(:each) but can't see how to do that.
09:52	duck1123	If I had a var to hook onto, something like add-hook would do well for me. (that way I could wrap my bindings)
10:23	_na_ka_na_	hellos, is there a way to change 'binding in all threads in this context' kinda thing? w/o doing alter-var-root
10:24	@rhickey	http://news.ycombinator.net/item?id=2054230
10:27	fliebel	rhickey: I looked as hard as I can at clojure.lang.Atom, but I still don't see why swap uses state.compareAndSet. I also came up with another alternative for the interface: Add a constructor that takes a AtomicReference. People can subclass that to customize atom in that case.
10:27	@rhickey	fliebel: I thought the question was why can't it be isA AtomicReference?
10:28	fliebel	rhickey: I asked to many in one go, I guess. I figured that one out I think.
10:29	@rhickey	fliebel: I think not as it applies to your suggestion right now - subclassing AtomicReference is futile as everything is final
10:29	Raynes	Intense. I've never heard such emotion rhickey before. I like it.
10:33	fliebel	rhickey: Atom is final, but AtomicReference doesn't seem to be. Or is that my mistake?
10:34	@rhickey	http://download.oracle.com/javase/1.5.0/docs/api/java/util/concurrent/atomic/AtomicReference.html
10:34	@rhickey	fliebel: look - all the interesting methods are final
10:35	fliebel	rhickey: I… need to refresh my Java. I didn't know methods could be final. Thanks for clearing that up. Back to the drawing board.
10:37	fliebel	rhickey: That leaves me with the swap question, why does it use state.compareAndSet? https://github.com/clojure/clojure/blob/master/src/jvm/clojure/lang/Atom.java#L81
10:39	fliebel	It seems Atom.compareAndSet would work, and handles validating and notifying just the same.
10:40	@rhickey	fliebel: it could, probably due to order of implementaiton
10:42	fliebel	rhickey: Splendid! Now, that means I can supposedly implement swap in Clojure and drop it of the interface. Objections?
10:43	@rhickey	fliebel: yes
10:45	fliebel	oh
10:46	@rhickey	why?
10:46	clojurebot	http://clojure.org/rationale
10:46	@rhickey	aargh
10:47	nickik	rhickey: I looked at dylen a bit and i think the multimethodes are pretty cool there too. Have you thougt about implementing something like dispatch on values? http://99-bottles-of-beer.net/language-dylan-225.html
10:48	@rhickey	nickik: yes, CL has dispatch on values
10:48	nickik	something like a standard dispatch function that works like dylans
10:48	@rhickey	fliebel: I don't want to preclude implementations of Atom that use locks
10:48	@rhickey	nickik: not interested
10:49	@rhickey	nickik: been there, done that
10:50	@rhickey	if you always want values, you can use identity as a dispatch function
10:50	@rhickey	mixing values and dispatch fn means double lookup
10:51	fliebel	rhickey: That… Is… a good point. So much to learn still… Thanks. :)
10:52	nickik	rhickey: ah ok so its for speed reasons or are there other objectives?
10:52	@rhickey	fliebel: you can interface-ize the stuff the Clojure code uses, but new interfaces that change the shape of things require design time - not a priority now
10:53	@rhickey	nickik: speed and simplicity
10:53	fliebel	rhickey: I understand.
10:53	nickik	rhickey: ok thanks I wounderd about that for a while.
11:00	_na_ka_na_	rhickey: In my tests I keep wanting a cousin of binding which binds across threads... is there a way out w/o using alter-var-root ?
11:01	@rhickey	_na_ka_na_: what does it mean to bind across threads?
11:09	_na_ka_na_	rhickey: I mean a construct like (binding-across-threads [a 10] @(future (prn a)) works ..
11:10	_na_ka_na_	but binding-across-threads can be spawned many times concurrently w/o affecting each other
11:10	_na_ka_na_	I don't know how to achieve that though
11:11	@rhickey	,(clojure-version)
11:11	clojurebot	"1.2.0"
11:11	_na_ka_na_	(map deref (map #(future (binding [a %] @(future (prn a)))) (range 2)))
11:12	@rhickey	_na_ka_na_: regular binding does that now in master
11:12	_na_ka_na_	oh, that's awesome! I'll take a look
11:13	_na_ka_na_	how about creating a bot which runs 1.3-master on IRC ?!
11:15	_na_ka_na_	,(try (finally (doseq [_ [1 2]])))
11:15	clojurebot	_na_ka_na_: I don't understand.
11:15	Bronsa_	lol
11:16	_na_ka_na_	@(try (finally (doseq [_ [1 2]])))
11:16	_na_ka_na_	I forgot how to run the Rayne's bot
11:17	_na_ka_na_	rhickey: I don't have a CA can I still submit a bug on jira?
11:17	edoloughlin	Does if-let treat nil as true? My code at https://gist.github.com/761119 isn't behaving as expected.
11:17	tonyl	&(try (finally (doseq [_ [1 2]])))
11:17	sexpbot	java.lang.UnsupportedOperationException: Cannot recur from catch/finally
11:18	_na_ka_na_	ah yes thx tonyl
11:18	tonyl	doseq uses loop/recur
11:18	_na_ka_na_	, (if-let [a nil] 1 2)
11:18	clojurebot	2
11:18	@rhickey	_na_ka_na_: yes, but not a patch without a CA
11:19	_na_ka_na_	edoloughlin, are you sure your expression in if-let returns nil?
11:19	_na_ka_na_	try inserting a trace
11:20	edoloughlin	_na_ka_na_ - yes. I'm using the (dbg) macro and also eval'ing it in the REPL
11:21	edoloughlin	My actual code returns the binding-form, which is set to nil
11:24	pdk	(doc dbg)
11:24	clojurebot	Huh?
11:24	cemerick	_na_ka_na_: no, you don't need a CA to submit a bug report.
11:27	edoloughlin	_na_ka_na_ - seems I'm suffering from blame-the-compiler syndrome. As soon as I share the problem I spot the cause. Thanks.
11:35	r2q2	hi
12:10	mduerksen	do i understand this correctly: protocols always establish a type-based dispatch, so i can't implement different methods for different keywords (inside the same method, i could of course still distinguish with a cond). right?
12:11	qbg	Right
12:12	nickik	they methodes dispatch on the first argument
12:12	mduerksen	ok, thanks
12:15	r2q2	Is there any code checked in for the clojure to clojure compiler?
12:16	nickik	there is alread a clojure in clojure compiler but not an offical one
12:16	r2q2	Where is that
12:16	nickik	i cant find it anymore
12:16	nickik	somewhere on github
12:17	r2q2	ok
12:19	nickik	its kind of hard to find we talked about it in here maybe you find something there
12:21	qbg	It was also announced on the group
12:22	r2q2	Oh i found it
12:23	r2q2	https://github.com/jarpiain/cljc for further refrence
12:51	TheLolrus	Hi. I'm a python programmer interested in clojure. Should I learn Java before learning Clojure?
12:51	dakrone	TheLolrus: it's not required at all
12:53	TheLolrus	OK. Would I be recommended to learn emacs? :P
12:54	headlessClown	A familiarity with the java virtual machine and classpaths isn't a bad idea but not necessarily java the language.
12:54	dnolen	TheLolrus: or NetBeans, or Textmate, or Vim, or Eclipse, or IntelliJ
12:54	headlessClown	lots and lots of clojure devs use emacs but there are other ways
12:54	clojurebot	clojure is making your sexp smile
12:55	Bronsa	Alol
12:55	TheLolrus	hmm if only there was a scribes plugin.
12:55	dnolen	TheLolrus: if you're not afraid of ruby, the cake project management tool you can pretty much use a regular text editor if you want.
12:55	headlessClown	Me personally, i tried vimclojure and the netbeans plugin before trying to learn emacs/slime/leiningen
12:56	headlessClown	And I'm sticking with emacs
12:56	TheLolrus	mkay. Would you guys recommend any tutorials besides the reference guide? A book perhaps?
12:57	TheLolrus	By the way the reason I don't want to learn emacs is I'm an impatient 13 year old. :P
12:57	qbg	TheLolrus: That is a good reason to learn emacs :)
12:57	TheLolrus	heh
12:57	headlessClown	Just start using emacs for any ole text editing
12:58	TheLolrus	I mean impatient to learn all the keyboard commands and get used to it
12:58	tonyl	TheLolrus, you can use any text editor
12:58	qbg	There aren't that many for basic use
12:59	headlessClown	I'm double your age, kid, and I picked up emacs (basic command set) this last summer :p
13:00	TheLolrus	Maybe next summer when I have freedom :D
13:01	TheLolrus	So are there any good clojure books or introductions? That explain it in detail. Then I can dive into the reference guide.
13:01	dnolen	TheLolrus: have you done much functional programming before?
13:02	headlessClown	There are couple on the book shelf and a couple that are releasing soon.
13:02	TheLolrus	well. Python has functions. I have tried C a few times but never got far in it. xP
13:02	TheLolrus	so not much.
13:02	qbg	Functional programming is more than just functions
13:03	TheLolrus	I thought so
13:03	TheLolrus	so no, then.
13:03	qbg	,(map inc [1 2 3])
13:03	clojurebot	(2 3 4)
13:03	TheLolrus	nope. :P
13:04	dnolen	TheLolrus: well Joy of Clojure is really good, but it assumes some experience w/ functional programming (FP)
13:04	qbg	Programming Clojure is nice also
13:04	dnolen	Stuart Halloway's book Programming Clojure is not a bad place to start, though perhaps getting long in the tooth now.
13:04	trptcolin_	TheLolrus: you might also take a look at http://learn-clojure.com/
13:04	qbg	A lot of it still applies
13:04	headlessClown	Has Joy of Clojure shipped yet?
13:05	headlessClown	ie the MEAP edition
13:05	r2q2	Maybe? http://www.amazon.com/Joy-Clojure-Thinking-Way/dp/1935182641/ref=sr_1_1?ie=UTF8&s=books&qid=1293818813&sr=8-1
13:06	qbg	It says Jan 28, 2011
13:07	headlessClown	ahhh
13:07	qbg	That bestsellers rank is far too low...
13:08	TheLolrus	how about http://www.youtube.com/user/briantwill#g/c/AC43CFB134E85266
13:08	currentB	simple question: what is the best way to generate a list filled with a given number of other lists, should i use for?
13:08	qbg	currentB: example?
13:09	qbg	,(repeat 5 [1 2 3])
13:09	clojurebot	([1 2 3] [1 2 3] [1 2 3] [1 2 3] [1 2 3])
13:09	qbg	?
13:09	r2q2	Aren't richhickeys webcasts still relevant
13:09	qbg	r2q2: They should largely still be
13:09	r2q2	TheLolrus: You should probably watch those
13:09	qbg	The syntax has changed since the older ones, but not much
13:10	currentB	yup repeat is perfect (sometimes i get hung up on which simple fn i'm looking for) thanks!
13:11	TheLolrus	I'm thinking those videos, then http://en.wikibooks.org/wiki/Clojure_Programming/Concepts , then http://java.ociweb.com/mark/clojure/article.html
13:12	mids	TheLolrus: sounds like a good start
13:19	mids	I just bought The Joy of Clojure e-book... the PragProg order process is so much nices than Manning :(
13:30	qbg	I reimplemented condp using my syntax-rules lib: https://github.com/qbg/syntax-rules/raw/master/src/qbg/syntax_rules/examples.clj (see ex-condp at the bottom)
13:30	qbg	I need a more powerful templating language eventually...
13:31	qbg	The syntax is simple, the template is hard...
13:32	Raynes	qbg: Why did you give the raw link? :o
13:32	Raynes	https://github.com/qbg/syntax-rules/blob/master/src/qbg/syntax_rules/examples.clj is prettier
13:32	Raynes	In any case, that is pretty awesome.
13:34	qbg	I'd try to reimplement for if I only understood how it works...
13:35	Raynes	for is insanity.
13:35	qbg	95+% of the work would be in the template anyways...
13:35	qbg	Probably not worth it.
13:35	Raynes	It's probably the one thing I'm having the most trouble explaining in my book. I've mostly left it as a placeholder until it comes to me in a dream or something.
13:36	Raynes	cemerick: Have you explained it in yours yet? /me will leech inspiration.
13:36	qbg	For is easy to implement in Scheme
13:36	qbg	(relatively easy that is)
13:37	qbg	continuations help a bit
13:40	qbg	I should make a release in the next few days
14:09	fliebel	I just noticed someone mentioned https://github.com/jarpiain/cljc in here. amazed What is the status of that?
14:26	pdk	considering it mentions the 1.3 alphas in the readme it's probably pretty recent
14:26	pdk	1.3 hasn't gone gold yet
14:49	cemerick	Raynes: explained what?
14:56	bhenry	what is non-lazy map?
14:59	qbg	cemerick: Raynes was talking about for
15:00	bhenry	i want to do a function with side effects to every item in a seq
15:00	cemerick	bhenry: (doseq [x some-sequence] (println x))
15:00	cemerick	for example
15:01	bhenry	thanks
15:06	pdk	do/doseq/dotimes basically exist for side effects
15:08	cemerick	qbg: yeah, we'll be covering for
15:10	TheLolrus	what's so good about maven?
15:10	pdk	the name sounds like mavis beacon
15:10	pdk	that's what we like with t
15:10	pdk	it
15:12	qbg	Maven treats XML like violence
15:13	TheLolrus	the enclojure site looks epic
15:13	TheLolrus	I wonder if it's made in clojure :P
15:17	cemerick	TheLolrus: this is now a bit old and out of date, but should give you some context about why one might use maven: http://cemerick.com/2010/03/25/why-using-maven-for-clojure-builds-is-a-no-brainer/
15:18	TheLolrus	mkay
16:03	amalloy	qbg: syntax rules is intimidating, even with the examples. the simple macros look promisingly simple, but even slightly non-trivial ones like -> are hard to follow. do you have a link to a good intro/tutorial?
19:05	devn	well, I won't be doing much for the next year
19:08	qbg	The title of Clojure in Small Pieces makes it sound like it would be like Lisp in Small Pieces, but it is not
19:08	qbg	(LiSP is a good book by the way)
19:59	pdk	where do you find clojure in small pieces
19:59	pdk	also is LiSP worth it if you've read graham's acl
20:13	Adamant	pdk: yes, it's a implementation of a language system book
20:13	Adamant	joshua__: agreed
20:14	pdk	so there's still stuff to learn from it
20:14	Adamant	joshua__: I've been known to pay for things then immediately use the pirated version due to that being the easiest
20:14	Adamant	pdk: probably, unless you're already a compiler geek
20:14	pdk	da f is with the pricing
20:14	pdk	is this like on lisp
20:14	Adamant	it's expensive
20:14	Adamant	they aren't printing more copies, IIRC
20:14	pdk	where there's a freebie version but a physical copy will cost you your first born
20:14	Adamant	check to see if they released a e-copy
20:15	pdk	not on kindle at least
20:15	Adamant	also look at several bookstores
20:16	joshua__	Adamant, I think I'm going to do that actually.
20:17	joshua__	The other funny thing is how much is charged for lets say, "Structure And Interpretation of Computer Programs."
20:18	joshua__	Charging well over $50 for a book that is free is a bit wacky to me.
20:18	Adamant	that's a hardback with pretty awesome binding
20:18	pdk	if you think it's bad take a look at on lisp
20:18	pdk	graham gives you a free pdf
20:18	pdk	or you could go $140 for hardcover
20:18	qbg	You could get LiSP from a good library
20:19	Adamant	$140 is most of a Kindle or half a NOOKColor
20:19	Adamant	more than half, actually
20:19	joshua__	I suppose that its a good thing that it is all overpriced for the dead tree edition. Less dead trees and all.
20:19	Adamant	mostly it's due to it not being reprinted
20:19	Adamant	I expect
21:11	Derander	Adamant: it's all of a kindle if you go for the wi-fi only version.
21:11	Adamant	Derander: not surprised
21:11	Adamant	I wasn't up on current prices :P
21:12	Derander	:-P
21:53	auser	is there a non-lazy form of filter?
21:56	cemerick	auser: doall will force evaluation of any lazy seq
21:56	auser	that's what I thought...
21:56	auser	thx
23:24	duck1123	What is a good clojure 1.3 replacement for re-partition?
23:33	joshua__	duck1123, what do you mean?
23:34	duck1123	re-partition was in str-utils, which is no longer in contrib 1.3
23:34	duck1123	so I'm trying to find a good replacement
23:37	joshua__	duck1123, I don't know, but the source is at https://github.com/richhickey/clojure-contrib/blob/a1c66df5287776b4397cf3929a5f498fbb34ea32/src/main/clojure/clojure/contrib/str_utils.clj#L28 if you can't find an option.
23:38	duck1123	I've been going through the dependencies of my application and seeing what it takes to get them all to play nice with 1.3. I'm working on autodoc right now
23:39	duck1123	the changes with the string-related libs has been a pain
23:54	replaca	duck1123: how's it going with autodoc? I haven't turned on 1.3 yet, but I have a new version in the works that should be more multiversion friendly
23:59	programble	happy new year!