#clojure – 2010-02-13

2010-02-13

00:01	underdev	qed: do you have those clojure yasnippets?
00:20	joshua-choi	Question: I'm looking at some undocumented reader macros. What do #< and #= do?
00:30	qed	,(doc #<)
00:30	clojurebot	Unreadable form
00:30	qed	,(doc #=)
00:30	clojurebot	EvalReader not allowed when read-eval is false.
00:39	somnium	b
00:52	gstratton	How do I persuade Leiningen to use my version of a jar instead of downloading its own?
01:05	gstratton	Ah, name it correctly
01:18	no_mind	how do I calculate the memory consumed by a clojure app
01:25	technomancy	no_mind: JMX is one way to do it
01:26	danlarkin	PIRANHAMOOOOOOOOOOOOOOOOOOOOOSE
01:27	qed	can anyone help me troubleshoot why my paredit is flaking out? I can't use C-) when I'm [\|] to slurp
01:27	qed	{} are behaving irregularly as well
01:34	qed	sigh -- what could have changed to screw this up so badly?
01:40	qed	i give up
01:51	piccolino	Is there some way to indicat directly that a function should be in a specific namespace?
02:53	LauJensen	Does anybody know of a catch-all location paramter you can pass to nginx, in order to trap all urls under a certain domain ? like md.dk, md.dk/one/two etc
02:58	LauJensen	Nvm, faked it
03:33	defn	hello
03:33	kmurph79	how is a hash map different from a hash?
03:38	defn	a hash map refers to key/value pairs, whereas a hash generally refers to the value alone within the context of a hash map
03:39	defn	err im sorry that's not right
03:39	defn	well, it sort of is
03:41	defn	kmurph79: does that make sense?
03:41	defn	you have a key, you run it through a hash function -- in a hash map you store the value in the container the key points to
03:42	defn	like :fred -> [Fred's phone number] -- The hash is Fred's phone number
03:42	kmurph79	yeah
03:43	noidi	that's not quite right
03:43	noidi	http://en.wikipedia.org/wiki/Hash_map
03:43	kmurph79	and a hash-map would the value and the number?
03:43	defn	yes
03:43	defn	errr, the key and the number
03:43	kmurph79	yeah
03:43	defn	:a -> "A", :b -> "B", and so on
03:43	defn	:a is a key, "A" is a value
03:44	defn	"A" is the hash, the whole thing is a hash map
03:44	morphling	kmurph79: do you come from ruby? they use "hash" short for hash map
03:44	defn	yes i was just going to say, many people use the two terms interchangeably
03:44	kmurph79	morphling: yes :)
03:44	defn	kmurph79: you may also hear someone talking about a "map" -- which can often refer to a hash map
03:45	defn	in clojure "map" could also refer to (map #(+ 1 %) [1 2 3])
03:45	defn	namely, the function map
03:45	defn	,(doc map)
03:45	clojurebot	"([f coll] [f c1 c2] [f c1 c2 c3] [f c1 c2 c3 & colls]); Returns a lazy sequence consisting of the result of applying f to the set of first items of each coll, followed by applying f to the set of second items in each coll, until any one of the colls is exhausted. Any remaining items in other colls are ignored. Function f should accept number-of-colls arguments."
03:46	defn	thats a whole lot of mumbo jumbo which means you apply some partial function to each element in a collection
03:47	defn	kmurph79: in clojure there are two ways that i know of to represent "partials" -- think of partials like half a function
03:47	defn	,(partial + 1)
03:47	clojurebot	#<core$partial__5034$fn__5036 clojure.core$partial__5034$fn__5036@f74015>
03:47	defn	,((partial + 1) 1)
03:47	clojurebot	2
03:47	kmurph79	ya, i understand map. i was listening to rhickey's talk on clojure, and he was throwing around the 'map' term a lot, so that clears that up
03:48	defn	,(map #(+ 1 %) [1])
03:48	clojurebot	(2)
03:48	defn	kmurph79: stop me if im droning on :)
03:48	kmurph79	defn: no, it's much appreciated
03:50	defn	kmurph79: lots of functions will use partials like #(function %1 %2 %3)
03:50	defn	% is just a placeholder for the value it's taking from the collection you're applying the function to
03:51	kmurph79	understood
03:52	defn	specicially %1 and %2 etc. are used when you have multiple collections
03:52	defn	like:
03:52	defn	,(map #(+ %1 %2) [1 2 3] [4 5 6])
03:52	clojurebot	(5 7 9)
03:54	kmurph79	yeah, i digested the map function awhile ago
03:55	Chousuke	defn: (map + ...) is enough :)
03:55	defn	Chousuke: sure -- I think they both demonstrate different things
03:55	kmurph79	so, a hash-map is just more efficient than a hash?
03:55	Chousuke	not really.
03:56	defn	one of them demonstrates #(fn %) (that syntax)
03:56	defn	the other demonstrates to pay attention to functions which takes multiple args
03:56	defn	take*
03:56	Chousuke	But #(+ %1 %2) is completely redundant since + already takes multiple parameters
03:56	defn	right, but the + in that example is completely unimportant
03:57	defn	Chousuke: i see what you're saying, though
03:59	Chousuke	more accurately, the %n symbol just refers to the nth parameter of the function, and map just feeds the function as many parameters as there are collections to map over.
04:00	defn	Chousuke: you're more right than me, but that doesn't stop me from being right as well
04:00	Chousuke	I thought you just made it sounds more complicated than it is :)
04:00	Chousuke	sound*
04:01	defn	i always feel like my explanations are pretty stupid sounding
04:02	defn	im a very visual learner though -- i learned #(fn %) before i learned how partials worked, because i thought partials seemed sort of scary at first
04:02	defn	then i learned they're the same thing -- then i learned how fns which take multiple args work in partials
04:03	kmurph79	is #() a partial?
04:03	Chousuke	the #() syntax is one way to construct a partial but it's not so limited. also, #() always creates a new function
04:03	Chousuke	a new Class, I should say
04:03	Chousuke	a call to partial does not.
04:05	Chousuke	I think the most common use for #() is (map #(.javaMethod %) ...)
04:05	Chousuke	or filter
04:06	defn	what about remove?
04:06	Chousuke	consider map a representative of the whole class of functions :)
04:06	defn	ah nvm, you said most common
04:06	defn	morning cgrand-rec
04:07	Chousuke	However, with clojure functions, #(foo %) is an anti-idiom because it creates a function that is pretty much equivalent to foo.
04:07	Chousuke	but if you need to fixate one of multiple args, #(foo % bar) or #(foo bar %) is pretty common as well
04:07	defn	fixate?
04:08	defn	to place within the context of a function's arguments? to place in a specific argument position?
04:08	defn	is that a fair definition?
04:08	Chousuke	I meant just "predetermine"
04:09	Chousuke	ie, make a "partial"
04:09	defn	ah ok
04:09	Chousuke	I guess just "fix" would have been more correct :P
04:09	defn	Chousuke: as long as I've got you in M-x teach-mode, could I ask for some help with refs, atoms, agents?
04:10	Chousuke	Sure. :P
04:10	defn	I understand (i think) how refs work, but there is a disconnect for me between real world application and what they are capable of
04:11	defn	do you have any examples for refs, atoms, or agents in a very simple real world context?
04:11	Chousuke	Heh. They are the construct you're supposed to use to make clojure to do real-world things. :)
04:11	defn	haha -- I realize what i'm saying is flawed as I'm saying it -- let me just shut up and say: "I don't really get refs/atoms/agents. Can you help me understand them better?"
04:12	Chousuke	if ignoring java interop, Clojure is purely functional and without refs, you can't mutate anything. You can't have state.
04:12	Chousuke	and most interesting programs require some state
04:12	Chousuke	so, Clojure provides you with managed constructs for it.
04:13	defn	i've heard the term mutate, and im not sure what that means in this discussion
04:13	defn	(sorry if this is remedial)
04:14	Chousuke	defn: Well, the reference types are really mutable. You can change them, unlike vectors or maps, which are values.
04:14	Chousuke	unlike traditional variables, however, the mutation semantics are well-defined
04:15	defn	so is my ref like my "int x=4;"?
04:15	defn	and then "print x" => 4, is that sort of like dereferencing?
04:15	Chousuke	it's closer to int *x = &four; where four is immutable
04:15	defn	ah-ha!
04:17	Chousuke	of course, C pointers have no concurrency semantics for mutation, which is the point of all the different ref types in Clojure.
04:17	defn	,(def x (ref 4))
04:17	clojurebot	DENIED
04:17	defn	:( clojurebot, be nice to me!
04:18	piccolino	Is there some easy way to take a Java Map<k,v> and turn it into a Clojure map? I must be missing something.
04:19	Chousuke	defn: atoms are uncoordinated but synchronous and mutable accross threads, while refs are coordinated and mutable accross threads. Agents are asynchronous, and Vars are only thread-locally mutable.
04:19	Chousuke	across*
04:19	Chousuke	meh, I'm making many mistakes today :P
04:19	Chousuke	piccolino: I think just (into {} java-map) should work
04:20	piccolino	Aha!
04:20	piccolino	Never thought to look for that.
04:20	defn	Chousuke: do you know of a good set of examples for each ref type?
04:20	Chousuke	hmm, not really.
04:20	defn	im just looking for something barebones which gets the point across
04:20	defn	damn..
04:21	defn	wanna write a few for me? ;)
04:21	defn	,(ref x)
04:21	clojurebot	java.lang.Exception: Unable to resolve symbol: x in this context
04:21	Chousuke	defn: there's this though http://github.com/technomancy/mire
04:21	defn	oh right -- i forgot about that...
04:22	zab	Anyone here successfully deployed a Compojure app to App Engine? I am about to give up. :/
04:22	defn	zab: not to app engine, sorry
04:23	Chousuke	well, atoms are simple: (def x (atom 1)); @x -> 1; (swap! x inc) -> 2; @x -> most likely 2, unless some other thread changed the atom between the swap! and deref
04:24	Chousuke	I think You might use an atom for eg. game state in a single-threaded game.
04:25	defn	Chousuke: if it was (def x (ref 1)); @x -> 1; (swap! x inc) -> 2; we could be sure that it is 2, simply because we used a coordinated mutable state reftype?
04:25	Chousuke	defn: refs don't support swap! at all. :)
04:25	defn	d'oh
04:25	defn	is swap part of the new transients stuff or am i way off?
04:26	Chousuke	nah, swap! is an atom thing
04:26	defn	,(doc swap)
04:26	clojurebot	Pardon?
04:26	defn	,(doc swap!)
04:26	clojurebot	"([atom f] [atom f x] [atom f x y] [atom f x y & args]); Atomically swaps the value of atom to be: (apply f current-value-of-atom args). Note that f may be called multiple times, and thus should be free of side effects. Returns the value that was swapped in."
04:26	defn	that sounds kind of like reduce?
04:27	Chousuke	It's nothing like reduce :/
04:27	Chousuke	it just changes the value of the atom
04:27	Chousuke	by applying a function to its current value
04:27	Chousuke	there's also reset! which sets an atom to a given value
04:29	Chousuke	With refs you would have a (def x (ref 1)) (dosync (let [a (ensure x)] (if (= a 1) (alter x inc) (ref-set! a 2))))
04:30	Chousuke	that would ensure that @x is 2 at the end of the transaction
04:30	Chousuke	oops. ref-set! x, not a.
04:31	Chousuke	using ensure instead of @ is probably not necessary in this case but it shouldn't hurt either
04:33	Chousuke	it's basically saying "I depend on the value of x in the transaction" so the transaction will restart if other transactions that have touched x finish first.
04:37	defn	sorry, stepped away for a second
04:37	defn	damned telcos...
05:46	djanatyn	Umm, sorry if I already said this, but does anybody know how to install clojure on Debian?
06:06	hoeck	djanatyn: I don't think its worth installing clojure via apt, as clojure consists only of a single jar, but it seems that there is a clojure.deb available
06:11	djanatyn	Ah.
06:11	djanatyn	Thanks.
06:23	zab	I have a question related to VimClojure. When I send my current file to the Clojure server, the preview buffer displays a list of all the defined macros.
06:24	zab	Then when I visit the locally running web server in my browser, my request times out and nailgun reports java.lang.OutOfMemoryError almost instantly.
06:30	cgrand	defn: morning :-)
06:31	zab	Oh right. I think it's because I don't know how to serve my servlet as a War file?
06:33	zab	Hmm. Confused. This is an App Engine app. How do people develop GAE apps without recompiling everytime?
06:39	konr	What do you use to generate pdf files?
07:03	LauJensen	Clojure has been #1 on DZone this morning, currently #2 :)
07:05	zab	LauJensen: Heh, your post is also on the front page of HN
07:05	LauJensen	aah right, cool
07:13	hoeck	konr: you can use iText (http://itextpdf.com/), but you basically have to buy a book describing it and author your documents in a pdf-oriented way
07:14	hoeck	konr: or use http://www.allcolor.org/YaHPConverter, a java-based html2pdf renderer and use some html-templating language from clojure
07:16	hoeck	konr: and then there are lots of other libs which let you basically write pdf source in java
07:17	StartsWithK	and batik can convert svg to pdf using apache fop
07:21	bsteuber	I used iText for some small project, you can more or less do it without a book if you're willing to google around and have a look at the javadocs
07:22	bsteuber	actually, I have built a small clojure wrapper around it for my purposes
07:24	hoeck	bsteuber: yes, I wouldn't mind buying the book, but at the time I looked at it there was only a book about an old iText version available :/
07:24	bsteuber	hm, then maybe it wasn't so bad I just used online resources
07:52	konr	hoeck: thanks! haha that's what I was considering too... the pdf libraries are so insanely verbose, that it's better to write html and convert
08:16	scode	technomancy\|away: I'm looking at making leiningen support system dependencies. Do you have any opinions on how? Mainly I'm considering having :jar-dependencies, but otherwise supporting some different syntax to :dependencies, such as "[:system name path/to/file". The latter seems cleaner.
09:13	yuuki	Can in be rebound with dynamic scope?
09:20	StartsWithK	yuuki, yes; see with-in-str or you can do it with binding
09:21	yuuki	sweet, with-bindings is what I was looking for
09:55	qed	Is there any interest in Clojure being a mentoring organization in the Google Summer of Code?
09:57	konr	it would be awesome
09:59	qed	the only thing I have to worry about is how many people want to play with clojure who beat me with their proposals
10:04	no_mind	qed, you will be surprised how many people lurk for GSoC
10:07	qed	no_mind: in here?
10:07	no_mind	qed yes, let google announce the names of organizations
10:08	no_mind	qed, I had been GSoC mentor twice and and both times more than one kid has beaten my expectation
10:09	qed	no_mind: so you think there's a good chance for Clojure in the GSoC this year?
10:10	no_mind	qed, clojure is getting popular and there is no restrictions on number of students. To start with you can take only one or two students for first year
10:10	no_mind	err
10:10	no_mind	I mean no restriction on the minimum number of students an organization intakes
10:11	qed	no_mind: well, I certainly hope clojure is one of the organizations. I'd kill to write Clojure for the summer.
10:12	no_mind	qed, sure. So who is going to be the admin ?
10:12	no_mind	qed, also Google has changed the format for organization signup this year. They are asking more questions upfront
10:12	qed	no_mind: i have no idea -- i think it's time to post to the list
10:13	no_mind	qed, yeah and if we want to be in GSoC we have to create an ideas page before applying
10:13	qed	if everyone puts their heads together in a few threads on the list I bet we could get it done
10:14	no_mind	qed, sure
10:14	qed	no_mind: since you've been a mentor you probably know a lot more than me. would you post something to the list about it?
10:14	qed	ill do anything i can to help
10:14	no_mind	qed, you start the thread and I will follow
10:14	qed	k
10:15	no_mind	qed, firs thing we have to decide is, whether we want to accept proposals for core clojure or for clojure contribs
10:20	qed	no_mind: I tossed something very basic up there to gauge interest. Feel free to reply with any information you might have on the topic.
10:20	no_mind	sure
10:22	no_mind	qed, which mailing list you had posted to ? google group ?
10:23	pdk	are gsoc applications open yet
10:24	qed	no_mind: yes the clojure google group
10:24	qed	pdk: mentoring organizations can apply Mar 8th => 12th
10:25	pdk	and students apply after then?
10:25	no_mind	pdk, no
10:26	no_mind	pdk, once google announces the list of orgs, there will be a 2 week period for students to interact with orgs
10:26	no_mind	then student applications open on march 29th
10:28	no_mind	qed, I dont see the post yet
10:37	triyo	LauJensen: you there?
10:40	triyo	Your post "My tribute to Steve Ballmer" was the best one so far. I used it to produce a ascii art of pic of "my wife, daughter and I" and got a nice frame to go with it and gave it to my wife for Valentines. ;-) thx for the idea. All that weighing in at $8 with pic frame.
10:56	LauJensen	trio - I'm glad you liked it - Hope the Mrs. and the little one are pleased :)
11:00	triyo	LauJensen: yup, indeed. Had to go with something different than the generic valentines gifts. On the serious note, good article. Keep it up.
11:00	qed	ditto. thanks Lau
11:04	LauJensen	np guys - great with some positive feedback, thanks
11:06	LauJensen	its actually been overwhelming well received, I thought I'd get some sucker punches because of the association with MS, but its been on the frontpage of HN all day, top of DZone and it just his reddit/r/programming/new
11:06	triyo	LauJensen: here is the result btw: https://dl.dropbox.com/u/2146210/aisha_and_alen_ascii_art.html
11:06	LauJensen	Thats great :)
11:06	triyo	LauJensen: this is fine, just don't do "x" VS "y" ;-)
11:07	triyo	then you get flamed
11:08	LauJensen	triyo, after I did the Ruby Scala post, Rich said "Its time to kick butt and chew bubble gum, and I'm aaallll outta gum", then I knew it was time to quit
11:08	triyo	LauJensen: the ascii pic came out nicely to on the actual print too
11:08	LauJensen	cool - Though I feel a little cheated that you didn't give her a picture of Steve Ballmer :)
11:09	LauJensen	(kidding)
11:09	triyo	hehehe, well if I wanted to share the shit our of my wife, it would have been my first choice
11:10	triyo	*share=scrar
11:10	triyo	e
11:10	triyo	scare
11:10	triyo	;)
11:11	triyo	Oh btw, anyone in the mood for a "your mother is so fat" joke? CS style that is?
11:11	LauJensen	alright - I gotta jet I'm in the middle of a very complicated project, so catch you all later and again, thanks for the feedback
11:11	triyo	cool
11:11	triyo	http://i.imgur.com/pPw3p.jpg
12:33	technomancy	how do you check for OS X in a shell script?
12:33	triyo	one sec I have it somewhere
12:34	triyo	I think I checked darwin on uname or something..
12:34	triyo	one sec
12:36	technomancy	anyone know what might be causing this kind of error when using Xbootclasspath on OS X? http://gist.github.com/303481
12:36	technomancy	putting clojure.jar on Xbootclasspath works great on Linux, but it bails when running tests on OS X
12:36	triyo	echo $OSTYPE
12:37	technomancy	triyo: what's that value on OS X?
12:37	technomancy	which makes debugging that much more annoying
12:37	triyo	if [[ $OSTYPE == 'darwin10.0' ]]; then
12:37	triyo	:)
12:38	triyo	not exactly perfect though... I'm trying to find my script that I have that actually only checks part of it as far as I can recall
12:39	triyo	actually its better to check on uname
12:40	triyo	like so:
12:40	triyo	uname=`uname`
12:40	technomancy	yeah, so that should be "Darwin"
12:40	technomancy	?
12:40	triyo	if [[ "$uname" == 'Darwin ]]; then
12:40	triyo	always
12:40	technomancy	cool
12:40	technomancy	thanks
12:40	triyo	np
12:41	triyo	then you can have your elif's for "Linux" "Cygwin", etc.
12:49	dabd	how do you refer to a Java inner class? I am trying Class$InnerClass but it is not working
12:55	chouser	dabd: that should work, but note you have to import that whole name
12:55	chouser	(import 'the.package.Class$InnerClass) ...then you can use just Class$InnerClass
12:55	dabd	chouser: I was just about to try that
14:14	rrc7cz-hm	what's the best way to recursively search a nested map structure? I know clojure.walk does something similar, but it appears to be more like a recursive map. I don't want to replace anything, just return the first matching node. Basically like seq-utils/find-first but recursive
14:19	hiredman	you can use find-first with tree-seq
14:20	hiredman	,(doc tree-seq)
14:20	clojurebot	"([branch? children root]); Returns a lazy sequence of the nodes in a tree, via a depth-first walk. branch? must be a fn of one arg that returns true if passed a node that can have children (but may not). children must be a fn of one arg that returns a sequence of the children. Will only be called on nodes for which branch? returns true. Root is the root node of the tree."
14:20	hiredman	,(tree-seq map? vals {:a {:b :c}})
14:20	clojurebot	({:a {:b :c}} {:b :c} :c)
14:25	rrc7cz-hm	hiredman: thanks, I'm playing with it now. In reality I have something like [{:a {:b :c}} {:a {:b :c}} {:a {:b :c}}
14:27	hiredman	rrc7cz-hm: output from clojure.xml/parse?
14:28	rrc7cz-hm	hiredman: when I find a match, I actually have to return a sibling's value. For example, if I search for :id=3, then [{:a {:b 1 :c 2 :id 3}} {:a {:b :c}} {:a {:b :c}}] should return let's say the value of :c, or 2
14:29	hiredman	that is a very differnt kettle of fish, you want to search keys and values
14:29	rrc7cz-hm	hiredman: correct, I think I screwed up my initial question
14:30	rrc7cz-hm	I'm searching for the first value match of a specific key, then returning a specific sibling's value
14:30	hiredman	have you looked at clojure.zip yet?
14:31	rrc7cz-hm	I believe I used it for some xml parsing a while ago, but I'll take another look at it
14:51	raek	for storing dates (no conversions or anything calculating-ish), is it worth it to use java Dates?
14:51	raek	...or should I just use a map?
14:52	arohner	raek: java Dates are fine
14:52	arohner	but as soon as you start calculating or converting, use Joda
14:53	raek	I want to parse "2009-02-13T19:52:12Z" into some internal representation and be able to format it back to the same format
14:53	raek	java uses year - 1900, right?
14:53	arohner	java uses unix time
14:56	raek	,(str (java.util.Date 2009 02 13))
14:56	clojurebot	java.lang.ClassCastException: java.lang.Class cannot be cast to clojure.lang.IFn
14:56	raek	,(str (java.util.Date. 2009 02 13))
14:56	clojurebot	"Sat Mar 13 00:00:00 PST 3909"
14:56	raek	hmm, yeah
14:57	raek	PST? how do I tell it that my datetime is in UTC?
15:02	arohner	raek: looks like you don't, from the java constructor
15:02	arohner	incanter has a wrapper lib around joda
15:02	arohner	it's nice
15:05	raek	that constructor has been deprecated since JDK 1.1, anyway..
15:05	arohner	raek: http://liebke.github.com/incanter/chrono-api.html
15:05	raek	arohner: ah, thanks!
15:08	arohner	is there a function that does conj, but if both items are not collections, makes a new collection?
15:10	raek	arohner: how do you mean? my intuitive interpretation of conj is "to collection X, add element Y"
15:11	raek	with maps, though, "Y" can be a map too
15:12	raek	maybe the source code for "->" has some interesting bits
15:12	raek	as -> turns the arguments into lists if they aren't
15:14	arohner	right, #(if (seq? %1) (conj %1 %2) (conj [] %1 %2)) works just fine
15:15	arohner	and I'm surprised I'm the only one with this problem. in clojure, that's usually an indication you're not doing things the right way
15:15	Chousuke	you might want to use coll? instead of seq?
15:15	Chousuke	,(seq? [])
15:15	clojurebot	false
16:40	avarus	hi!
16:40	jimt	good morning!
16:41	avarus	heh, almost :)
16:42	avarus	I'm having a problem with data types and jdbc it seems
16:43	avarus	I play around with contrib.sql and my pgsql server and I struggle with strange error messages about wrong types
16:43	avarus	first I had the problem with timestamps, now with boolean :)
16:43	avarus	when I want to update or insert a boolean type contrib.sql spits out an error or does nothing
16:43	avarus	even doesn't hit the database at all
16:43	avarus	that's really odd
16:44	avarus	I tried to do something like (boolean true) e.g. and I got one run where it worked
16:44	avarus	but the same app, still running doesn't work anymore :P
16:44	avarus	so after I googled the java guys use something like "java.sql.Types.BOOLEAN"
16:45	avarus	but how can I do it in clojure?
16:45	LauJensen	~clojureql
16:45	clojurebot	clojureql is http://gitorious.org/clojureql
16:46	avarus	I check it out, thx
16:49	avarus	looks interesting :)
16:50	avarus	I'll try it
16:50	kevin_lm	Hi! Any enlive users out there know how if it is possible to specify an adjacent selector. i.e. [E + F]?
16:52	Leafw	I am getting a very weird error: I import one class, but clojure complains about some other class not being found (?) which I never use or import in this code. What sense does that make?
16:52	Leafw	from the interpreter.
16:53	Leafw	repl
16:53	avarus	which is?
16:53	avarus	the error I mean
16:53	Leafw	(and, in any case, that other class is in a jar in the classpath anyway)
16:53	Leafw	java.lang.NoClassDefFoundError: mpicbg/models/CoordinateTransform (FFT_frequency_range_to_stack.clj:56)
16:54	Leafw	I never import or use that class in my code.
16:54	avarus	what libs are you using?
16:54	Leafw	our own lib: imglib.jar
16:54	Leafw	the class that it "cannot find" is in the mpicbg_.jar, which has classes that also start with "mpicbg.*"
16:55	Leafw	both jars in classpath. But I cna't see how it should matter
16:55	Leafw	this error is total astroturf, like C going over an array limit and complaining later about something else
16:55	avarus	hehe
16:55	Leafw	not a good thing.
16:57	Leafw	if anybody has seen import-related errors like this, let me know what can cure clojure of this total mishap
16:57	avarus	LauJensen: I guess selecting from my own server-stored pgsql functions just works, right? :)
16:58	avarus	Leafw: are you building the final jar or what?
16:58	Leafw	avarus: no, just running a script with load-file
16:59	avarus	and I guess the line number it tells you is utterly useless
16:59	Leafw	putting the imports under the ns declaration at the top also incurs in the same error
16:59	Leafw	no, that line number is where the import was.
16:59	avarus	ook
17:00	Leafw	the import for that other class, which is unrelated except for having the same "mpicbg.*" start of the qualified name
17:00	LauJensen	avarus: I hope so :)
17:00	avarus	oh oh :)
17:01	Leafw	I donn't understand what the import function or macro is doing, but it's doing the wrong thing when there are classes with same start of package name, stored in different jar files.
17:02	guille_	hi
17:02	raek	is there a simple way to filter the keys of a map?
17:02	Leafw	importing the class that "can't be found" (I never imported nor needed it) directly works.
17:03	avarus	perhaps you found a bug
17:03	Leafw	raek: (filter <pred> (keys somemap)) ?
17:03	raek	i want a function that returns a map, which keys are the union of some "allowed" keys and the actual keys
17:03	Leafw	more than a bug, this is a calamity. A total show stopper.
17:04	Leafw	imports are so much unlike the rest of clojure.
17:05	guille_	raek: maybe http://richhickey.github.com/clojure/clojure.core-api.html#clojure.core/disj ?
17:05	raek	maybe (into {} (filter #(#{:a :b :c} (key %)) somemap))
17:06	raek	I want to remove all bindings in a map, except those whose keys are in a set
17:06	chouser	,(select-keys {:a 1, :b 2, :c 3} [:a :b])
17:06	clojurebot	{:b 2, :a 1}
17:07	raek	chouser: perfect! thanks...
17:13	avarus	LauJensen: so I installed gradle and clojuresque and cloned the clojureql repository, now what? :) the readme.markdown says something aboyt ivy a, not gradle
17:13	avarus	-a
17:14	avarus	same as in clojuresque? gradle build?
17:14	avarus	I'll try
17:14	avarus	na, that fails, mhh...reading again, I must have missed something
17:15	LauJensen	avarus: http://www.bestinclass.dk/index.php/2009/12/clojureql-where-are-we-going/
17:15	LauJensen	There's a section on building
17:17	avarus	ya, "Building the thing"
17:19	avarus	"Gradle will handle that automatically once you build ClojureQL." but then there is already "In closing" :)
17:19	avarus	or perhaps I misunderstood the part that gradle needs the jar clojuresque jar :)
17:20	avarus	ya, ok, "gradle build" is all I need regarding tghe mailinglist
17:23	avarus	but it fails with this: http://pastie.org/823735
17:24	avarus	settings.gradle only contains "rootProject.name = clojureql"
17:25	LauJensen	Did you see both ENV vars correctly ?
17:25	avarus	http://pastie.org/823736 <-- verbose
17:25	avarus	yes, I do
17:25	avarus	bin of gradle is in the path and GRADLE_HOME shows the home dir of gradle
17:26	LauJensen	If PATH contains the bin, and GRADLE_HOM points to the Gradle root, then enter your newly cloned clojureql root dir and hit 'gradle build', thats it
17:26	LauJensen	No need to install clojuresque since the build script declares it as a dependency
17:26	avarus	ya, too late :) I followed your instructions and then read it's not needed :P
17:26	LauJensen	Sorry - I will practice blogging more
17:27	avarus	but that's not the problem here, I think
17:30	avarus	org.gradle.api.GradleScriptException: Settings file '/Users/andreas/clojure/clojureql/settings.gradle' line: 1
17:30	avarus	it sounds quite obvious to me but I don't know what's being expected there in line 1
17:31	LauJensen	Did you clone the main repo ?
17:32	avarus	git clone git://gitorious.org/clojureql/clojureql.git <-- is that the main repo?
17:32	LauJensen	yes
17:32	LauJensen	http://gitorious.org/clojureql/clojureql/blobs/master/settings.gradle
17:32	avarus	same content as here :)
17:33	LauJensen	ok- please delete that file locally, try again
17:34	avarus	did it! :)
17:35	r0man	,(= #"" #"")
17:35	clojurebot	false
17:35	r0man	, (= (str #"") (str #""))
17:35	clojurebot	true
17:35	r0man	hello #clojure, i'm wondering about regex equality. why is this? because of java interop?
17:37	r0man	,[(= #"" #"") (= (str #"") (str #""))]
17:37	clojurebot	[false true]
17:37	LauJensen	I apologize for the trouble
17:38	avarus	lol! np :). I am the one thanking you if that piece of software is helping me on my way to the millions of dollars I dream of :P
17:39	LauJensen	I strongly recommend not dreaming about money
17:39	avarus	ok, I'll earn it :)
17:54	raek	is there a simple way to do a map (function) like thing, but on the values of a map (data structure) instead of on a seq?
17:55	raek	if I had made it, I'd call it map-val
17:56	raek	hmm, clojure.contrib.datalog.util/map-values
17:57	LauJensen	(map f (vals m))
18:06	raek	well, I want the result to be a map too...
18:06	raek	here's my solution:
18:06	raek	(defn map-vals [f m] (into (empty m) (for [[k v] m] [k (f v)])))
18:24	JonSmith	If i'm using fleetdb, can I just run it in my existing clojure image instead of using the client library?
18:26	arohner	JonSmith: I don't know, but I'd be surprised if you can't
18:33	JonSmith	okay
18:33	JonSmith	well i will try and see
19:55	jwhitlark	so, 0xFF in the repl gives me 255, but (byte 0xFF) gives me -1. Any suggestions on how to get a byte with all the bits set?
19:55	gstratton	(and (byte 0xff)
19:56	raek	jwhitlark: I think you got it
19:56	_ato	java byets are signed
19:56	jwhitlark	(and (byte 0xff))
19:56	jwhitlark	oops.
19:56	raek	,(and (byte 0xff))
19:56	clojurebot	-1
19:56	raek	(and (byte 0xff) (byte 0xab))
19:56	raek	,(and (byte 0xff) (byte 0xab))
19:56	clojurebot	-85
19:57	_ato	-1 = 11111111 in two's complement
19:57	_ato	http://en.wikipedia.org/wiki/Two%27s_complement
19:57	_ato	,Byte/MAX_VALUE
19:57	clojurebot	127
19:58	raek	java doesn't have any unsigned values at all, right?
19:58	jwhitlark	ok. I'm trying to construct a magic packet for wake on lan, I was using (repeat 6 (byte 0xff)), the (into-array (Byte/TYPE)) xxxx) on the result.
19:59	raek	,(format "%x" (byte 0xff))
19:59	clojurebot	"ff"
19:59	_ato	that should work
20:00	jwhitlark	_ato: the code I have should work?
20:00	jwhitlark	I must be doing something else wrong.
20:00	_ato	yes, signed -1 = unsigned 255, so the network card will interpret it has 0xff
20:01	_ato	I'd use a packet sniffer and compare what your code is sending to some other implementation and see if there's a difference
20:01	raek	(byte-array 6 (repeat 6 (byte 0xFF)))
20:03	raek	does the array from into-array get its size from the seq?
20:03	jwhitlark	I thought so.
20:04	_ato	,(count (into-array Integer/TYPE [1, 2, 3]))
20:04	clojurebot	3
20:04	jwhitlark	I'm passing the length in later, so as long as the data is there, (and I checked with aget), it should work...)
20:04	avarus	has anyone ever experimented a bit with contrib.sql and pgsql? :(
20:04	raek	ah, ok. nevermind... :)
20:04	jwhitlark	I'll try wireshark
20:09	avarus	I'm having a problem updating simple data by id which is a number
20:09	avarus	I get an exception because pgsql fired an error due to type mismatch
20:10	avarus	or I get no exception but nothing has changed
20:10	avarus	no data being affected
20:10	avarus	contrib.sql is not hitting the db then
20:13	tolstoy	There's no official clojure 1.1 jars at clojars for leiningen to grab?
20:16	_ato	it's here http://build.clojure.org/releases/
20:16	_ato	build.clojure.org/snapshots is in lein's default repo list but not releases
20:16	_ato	guess I should mirror them on clojars too
20:16	_ato	hmm
20:17	danlarkin	build.clojure.org is stable
20:17	tolstoy	lein has a default project file it builds.
20:17	tolstoy	I've not problem finding clojure and clojure contrib.
20:17	tolstoy	Was just curious to have lein find them as part of its deps.
20:18	tolstoy	The default project file has 1.1.0-alpha-SNAPSHOT for clojure, and "1.0-SNAPSHOT" for contrib.
20:20	tolstoy	That would be cool! ;)
20:21	tolstoy	I've developed a couple of little projects in clojure but didn't use lein. And now I'm trying it, and feel stymied right at the start! :)
20:24	_ato	ok done. give [org.clojure/clojure "1.1.0"] a try
20:25	tolstoy	Ah! Will, do.
20:25	tolstoy	Is there any more documentation on lein than the github readme?
20:26	tolstoy	_ato: That works well. Thanks!
20:26	_ato	not official documentation, there's a couple of random tutorials, just google: leingingen tutorial
20:26	tolstoy	Okay. Yeah, for instance, how do you make your uberjar know where the main class is? Stuff like that.
20:27	tolstoy	ah, lein help jar gives me the details. phew!
20:27	_ato	yep, and the README does mention briefly: :main - specify a namespace to use as main for an executable jar
20:27	tolstoy	Gotcha.
20:42	jwhitlark	ah. I got it. I was parsing the mac address wrong.
20:42	jwhitlark	(map #(byte (Integer/parseInt % 16)) (re-split #"\:" mac)) works properly.
20:42	jwhitlark	thanks for the help.
20:48	tolstoy	Hm. I want a "lein swank". ;) And a "lein run".
20:49	_ato	http://github.com/technomancy/leiningen/tree/master/lein-swank
20:50	_ato	http://github.com/ericlavigne/leiningen-run
20:51	tolstoy	Nice!
21:00	tolstoy	Hm. leiningen run requires all those jars?
21:03	_ato	odd, looks like it pulls in maven-ant-tasks by mistake
21:04	tolstoy	That's a mistake? I was just looking at that project.clj
21:04	_ato	well it doesn't seem to use it
21:05	tolstoy	Maybe the "exclude" thing will help?
21:06	tolstoy	Hm. That didn't work.
21:06	_ato	could do, 'fraid I haven't used excludes or that leiningen run. I either use SLIME or bite the bullet and do the full: java -cp 'src:lib/*:classes' clojure.main -e "(use 'something)(-main)"
21:06	_ato	guess I should turn that into a shell alias or script to save typing it out all the time
21:07	tolstoy	Yeah, I'm okay with that sort of thing to. Nice custom "run" and "swank" scripts.
21:07	seths	lein run is awesome
21:08	seths	at least it makes me happy :-)
21:08	tolstoy	seths: Yeah, but it seems to require 23 jars.
21:08	tolstoy	lein exclusions work only for dependencies, not dev-dependencies, it seems.
21:14	tolstoy	looks like exclusions don't work at all. maybe the readme is wrong, or that's not in the stable version
21:15	seths	tolstoy: as long as you lein clean before uberjar, it's not an ongoing annoyance
21:15	tolstoy	I spose.
21:15	seths	not ideal mind you
21:15	seths	I'd love it to be part of lein
21:15	seths	(just a happy user of both)
21:17	tolstoy	I don't understand why lein-run requires maven-ant-tasks.
21:19	tolstoy	For instance, if I delete all those extra dependencies, lein run still works.
21:20	seths	heh
21:23	tolstoy	lein-swank includes them too!
21:23	seths	another plugin I'd like to see in core
21:24	seths	lein 1.1 should be coming out soon I think. After that might be a good time to fork & issue pull requests on github
21:24	seths	I'm trying to figure out why putting clojure.jar in -Xbootclasspath:/a causes lein test to get all grumpy
21:24	tolstoy	Hm.
21:25	seths	not on Linux, only on Mac so far
21:25	tolstoy	Each of them (swank and run) seem to require maven because they don't really run in the same context as leiningen.
21:27	tolstoy	All this would be okay of :exclusions worked.
21:27	avarus	no! it was a fucking simple typecast!
21:27	seths	rofl
21:27	seths	IRC is great at random times
21:28	avarus	can't believe it was so simple
21:30	avarus	now, god, please rewind the last 6 hours of my live, please!
21:30	avarus	life :>
21:30	avarus	narf
21:39	JonSmith	,0xFF
21:39	clojurebot	255
21:41	tolstoy	Ah hah. Leiningen stable doesn't have the exclusion stuff.
21:50	avarus	guys...I have to sleep! :P
21:50	avarus	good night
22:03	JonSmith	is there a good filesystem ultilities library yet
22:03	JonSmith	?
22:03	JonSmith	like
22:03	JonSmith	files in a directory, navigate up and down etc.
22:16	mattrepl	tolstoy: get :exclusions issues worked out?
22:17	tolstoy	Yep.
22:17	tolstoy	Turns out the "stable" version didn't have that feature.
22:26	Drakeson	In the ns macro, how can I :require or :use a namespace that only differs in its last term (after the last .), with the current namespace? (IOW, a namespace relative to the current one)
22:28	tolstoy	Drakeson: You don't just use the fully qualified name?
22:30	Drakeson	sometimes it is a bit cumbersome
22:30	tolstoy	Indeed.
22:30	Drakeson	especially when you want to move/rename things around
22:31	tolstoy	I think the names spaces translate to java packages, and they're all relative to the classpath, not the place where the file actually is.
22:31	tolstoy	Yeah.
22:31	_ato	yeah there's no relative imports
22:31	tolstoy	In Java, you don't have to import class that are in the same package, but it's still a problem to move things from package to package.
22:31	tolstoy	Thus, Eclipse and the like.
22:35	tolstoy	Can you splice arrays outside of a macro? `@list, or something like that?
22:37	_ato	,(let [stuff [1 2 3]] `["hi" ~@stuff "there"])
22:37	clojurebot	["hi" 1 2 3 "there"]
23:01	JonSmith	hm
23:01	JonSmith	i bet you could write an uber-ns macro that uses a heriarchy for require and use
23:20	piccolino	Does proxy invoke the compiler every time it's called?
23:24	_ato	no, if I remember correctly it generates one class (per parent class + interfaces) at compile time with method stubs that just call a fn pointer, then each time you call proxy it just creates an instance of that class and plugs in your proxy functions.
23:26	piccolino	OK, cool, thanks _ato.
23:29	_ato	,(class (proxy [Thread] []))
23:29	clojurebot	java.lang.IllegalStateException: Var null/null is unbound.
23:30	_ato	,Thread
23:30	clojurebot	java.lang.Thread
23:30	_ato	guess clojurebot disallows it
23:30	_ato	but it evals to: clojure.proxy.java.lang.Thread
23:30	_ato	which is that one class that all proxies of Thread will be instances of
23:30	piccolino	Yeah, I just tried it in the repl.
23:34	piccolino	And there's no way to give a proxy object a member variable?
23:38	tolstoy	piccolino: The methods you override are full closures, so you could make use of that, maybe.
23:39	tolstoy	(let [instance-var (init)] (proxy ....... (some-fun [] (use instance-var) ....)) etc, etc.
23:39	tolstoy	Poor man's subclass?
23:40	piccolino	Hm, OK, thanks.
23:41	tolstoy	piccolino: All I know is that if you proxy a class that calls an abstract method in its constructor, you're screwed.
23:41	piccolino	Heh, don't need that fortunately.
23:42	tolstoy	Yeah. I learned that after many hours of dealing with code in which the dev seems to think the constructor was the place for 90% of the business logic.