#clojure – 2009-09-14

2009-09-14

02:59	lowlycoder	is there anyway to use vim keybindings in enclojure?
03:28	LauJensen	Top o' da morning gents
03:42	Fossi	hi
04:33	LauJensen	(defn fac [x] (if (zero? x) 1 (* x (fac x))))
04:34	hiredman	you are missing a dec
04:34	LauJensen	yes, add the dec, then help me understand why I cant replace the last expression with (* x (recur (dec x))
04:34	LauJensen	If I wanted to add tail recursion that is
04:35	hiredman	that's why you make a factorial sequence generating function use nth
04:35	Chousuke	the expression is not tail recursive.
04:36	LauJensen	Chousuke: No the question is, how would I make it so ?
04:37	Chousuke	the fac function needs an accumulator parameter for that.
04:37	Chousuke	and then you just need to return the accumulator at the end of the recursion
04:37	LauJensen	ah yes
04:37	LauJensen	Thanks
04:48	LauJensen	Can someone explain currying real quick for me ?
04:50	Chousuke	isn't it the approach that all functions take only one parameter?
04:50	Chousuke	ie. a function that "has two parameters" really takes just one and returns a function that takes the other parameter.
04:50	LauJensen	Currying is the process of transforming a function that takes multiple arguments into a function that takes just a single argument and returns another function if any arguments are still needed. f :: a -> b -> c
04:51	LauJensen	Thats from the Haskell wiki - No different for Clojure I hope ?
04:51	hiredman	well, haskell currys automagically
04:51	hiredman	clojure doesn't
04:53	Chousuke	currying also neatly explains why the type notations in haskell are what they are :)
04:54	Chousuke	I really had trouble with them until I understood the "one argument only" idea :/
04:54	liwp	if you wanted to write non-curried Haskell you could use tuples everywhere: f :: (a, b) -> c
04:54	liwp	(not saying it's a good idea ;-)
04:54	hiredman	,((((curry +) 1) 2) 3)
04:54	clojurebot	#<sandbox$uncurry__2574$uc__2576 sandbox$uncurry__2574$uc__2576@1860045>
04:54	hiredman	,(((((curry +) 1) 2) 3))
04:54	clojurebot	6
04:55	liwp	but that's how the authors approach currying and higher order functions in The Little MLer and it works quite well in the book
04:56	LauJensen	Alright thanks
04:56	LauJensen	Then just to clear our factorial discussion up, this is the way to implement a durable factorial
04:56	LauJensen	(defn fac ([x] (fac 1 x))[acc x] (if (zero? x) acc (recur (* x acc) (dec x))))
04:58	liwp	looks good
04:59	LauJensen	So sad that the JVM doesn't have tail recurrence
04:59	liwp	I really like how defining the same fn with different arities lends itself to defining helper functions
04:59	liwp	LauJensen: indeed. Hopefully they'll fix it at some point, but I'm not holding my breath
04:59	LauJensen	'lends itself' ?
05:00	liwp	you can use the feature to define helper methods
05:00	LauJensen	Yes thats true
05:01	liwp	in Haskell you'd probably define the two arg helper as an internal definition in a where expr
05:01	LauJensen	In the danish IT press, it's what we got hammered for. Verbosity. But I think the people doing the hammering spoke for an inferior intellectual viewpoint.
05:01	liwp	verbosity? Surely that's less verbose than doing the same thing (method overloading) in Java?
05:02	LauJensen	See comment regarding IQ of critics
05:08	liwp	hehee
05:08	rfgpfeiffer	,((comp (partial apply *) (partial range 1) inc)) 5)
05:08	clojurebot	java.lang.IllegalArgumentException: Wrong number of args passed to: core$inc
05:09	liwp	,((comp (partial apply *) (partial range 1) inc) 5)
05:09	liwp	,((comp (partial apply *) (partial range 1) inc) 5)
05:09	clojurebot	120
05:10	rfgpfeiffer	* is tail recursive enough
05:15	LauJensen	,((comp (partial apply *) (partial range 1) inc) 5000)
05:15	clojurebot	42285779266055435222010642002335844053907866746266467488497824021813580527081082006908990478717063875370847466573006854458784860666838127363372108937727876312793903630584621606439044789869822398719297088962116126529683217755003992421968370314690726447287878979040475488416221522667192841096923691044956597173635294840022384038112064482023085767110450230617489475542830976178172404080532480992780932878405548619936454829121187
05:15	LauJensen	Wow
05:15	LauJensen	How did you come up with that rfgpfeiffer ?
05:16	rfgpfeiffer	well that's how i wold write it
05:17	rfgpfeiffer	hiding recursion
05:17	LauJensen	Can you explain the steps please?
05:17	liwp	you create a seq of the number you want to multiply together: (range 1 (inc n))
05:18	liwp	and then you apply * to the seq
05:18	liwp	rfgpfeiffer: very nice
05:18	rfgpfeiffer	(defn fac [n] (apply * (range 1 (inc n))))
05:18	liwp	,(apply * (range 1 (inc 5)))
05:18	clojurebot	120
05:18	LauJensen	ooh
05:18	rfgpfeiffer	and then I made it point-free
05:19	LauJensen	I'm amazed
05:19	LauJensen	That's a new mindset to me entirelyu
05:19	rfgpfeiffer	hiredman: can clojurebot refactor to point-free style like lambdabot?
05:20	rfgpfeiffer	LauJensen: Read http://github.com/raganwald/homoiconic
05:20	LauJensen	Will do
05:21	Chousuke	I don't like point-free style in Clojure.
05:21	Chousuke	most of the time it just doesn't work
05:21	Chousuke	as in, improve readability :P
05:23	rfgpfeiffer	There is a website about complicated implementations of factorial in Haskell
05:23	hiredman	,(pl ((partial apply *) · (partial range 1) · inc 5))
05:23	clojurebot	120
05:23	Chousuke	for example, the earlier point-free fac function is just ugly compared to the explicit defn (It's not the programmer's fault :))
05:24	hiredman	eh? ugly to you
05:24	Chousuke	all the comp and partial calls are just noise.
05:24	hiredman	#() is noise
05:24	Chousuke	no, it's not.
05:24	hiredman	comp is compose and partial is partial
05:24	Chousuke	but it doesn't even apply in this situation
05:25	liwp	Chousuke: I agree. I think point-free look a lot nicer in haskell
05:25	Chousuke	hiredman: yes, but using them obfuscates what teh function actually does
05:25	hiredman	Chousuke: #() is usually what is used instead of comp and partial
05:25	liwp	in Clojure / lisp the prefix syntax just makes it ugly
05:25	hiredman	Chousuke: no, it makes it clearer
05:25	hiredman	the function is a composition of the other functions
05:26	hiredman	the function is the partial application of this function to this argument
05:26	Chousuke	sorry, but how the hell is (comp (partial apply ) (partial range 1) inc) clearer than (apply (range 1 (inc n)))
05:26	rfgpfeiffer	that is unfair
05:26	Chousuke	the latter reads "product of range from 1 to n"
05:26	rfgpfeiffer	it should be #(apply * (range 1 (inc %)))
05:26	Chousuke	rfgpfeiffer: well that's still much nicer.
05:27	rfgpfeiffer	yeah
05:27	hiredman	thats like, your opinion, man...
05:27	Chousuke	I can't understand how you think the point-free style better in this case.
05:28	Chousuke	the comp and partial calls tell nothing about what the function does.
05:28	LauJensen	How do you guys define point-free?
05:28	Chousuke	or what the code does.
05:28	liwp	~google point-free style
05:28	clojurebot	First, out of 194000000 results is:
05:28	clojurebot	Pointfree - HaskellWiki
05:28	clojurebot	http://www.haskell.org/haskellwiki/Pointfree
05:28	Chousuke	unlike in, say (partial merge-with +) that I used earlier. that's small and simple and says "merge-with +"
05:29	liwp	LauJensen: another one on Stack Overflow: http://stackoverflow.com/questions/944446/what-is-point-free-style-in-functional-programming
05:29	rfgpfeiffer	~google evolution of haskell factorial
05:29	clojurebot	First, out of 1500 results is:
05:29	clojurebot	The Evolution of a Haskell Programmer
05:29	clojurebot	http://www.willamette.edu/~fruehr/haskell/evolution.html
05:29	rfgpfeiffer	cool
05:29	LauJensen	Thanks guys, what a community :)
05:30	Chousuke	I'm just saying that while there are cases where point-free style is better, it doesn't really fit Clojure.
05:30	liwp	rfgpfeiffer: you can't port your factorial to haskell though because haskell doesn't have apply. You'd have to use reduce and that then makes the definition a bit more complicated
05:30	liwp	Chousuke: yeah, I agree
05:30	liwp	too much noise in a lot of cases
05:31	rfgpfeiffer	fac = foldr (*) 1 . enumFromTo 1
05:31	liwp	rfgpfeiffer: ok, fair enough ;)
05:32	Chousuke	that's already much better because of the implicit partials and . for comp :P
05:32	rfgpfeiffer	you could use reduce instead of apply in clojure too
05:32	LauJensen	rfgpfeiffer: You're git repo yields one question, whats 'chutzpah' ?
05:32	liwp	There was a post on the list recently that showed a use for point-free style that actually didn't look too bad: http://groups.google.com/group/clojure/msg/ae2c655c76a2b56b
05:33	liwp	But even there the reader must do a double take on the code IMHO
05:33	liwp	rfgpfeiffer: yeah of course, I just mean that having apply in clojure makes the factorial even nicer
05:33	rfgpfeiffer	LauJensen: what?
05:34	LauJensen	"He said he let her off on the grounds of novelty and chutzpah."
05:34	rfgpfeiffer	i mean it is a yiddish word that means boldness
05:34	rfgpfeiffer	but what repo
05:34	LauJensen	homoiconic
05:34	rfgpfeiffer	or ruthlessness
05:35	rfgpfeiffer	okay
05:36	liwp	is there a foldr1 in haskell... then you'd get fac n = foldr1 (*) $ enumFromTo 1 n
05:39	rfgpfeiffer	factorial should be in core.clj
05:39	rfgpfeiffer	so we have a shorter definition than haskell :)
05:40	hiredman	add a ! special form
05:41	rfgpfeiffer	On a more serious note: has anybody used java.nio and selectors with clojure?
09:45	crios	Hello, I'm studying the code in http://pastebin.com/m2dc9a491. How: (bench-fn (fn []> (+ 1 2))) is different from: (bench-fn (fn [] (+ 1 2))) ?
09:45	crios	what does it mean "fn []>" syntax ?
09:52	AWizzArd	crios: a typo
09:58	Chousuke	interestingly enough the code works like that too :)
09:59	Chousuke	the > is just ignored.
09:59	Chousuke	because it's just the > function :P
10:02	crios	I don't understand
10:02	Chousuke	crios: it's the same as:
10:02	Chousuke	,(do > 5)
10:02	clojurebot	5
10:03	Chousuke	it just gets ignored because it's not a function call, it has no side-effects and it's not the last expression in the body so it doesn't get returned either.
10:10	Fossi	wouldnt work with #( though
10:11	Chousuke	well, that's because #( is not (fn :P
10:11	Fossi	or it would return true then
10:11	Chousuke	hm
10:12	Chousuke	,(> 3)
10:12	clojurebot	true
10:12	Chousuke	I guess that's useful for checking if a seq of numbers is sorted.
10:14	AWizzArd	,>
10:14	clojurebot	#<core$_GT___4136 clojure.core$_GT___4136@18b995c>
10:34	crios	so does > character, in that contest, is a of real value?
10:39	Fossi	no, it doesn't do anything senseful. it's a "bug" in the book, as the first hit on google (the errata) also tell
10:42	crios	Fossi, here http://www.pragprog.com/titles/shcloj/errata ?
10:42	Fossi	yes
10:43	Fossi	see 233 or such
10:46	achim	crios: if you don't understand what's going on, imagine what a call to foo would return in this case: (defn foo [] 3 5 < :bar + (/ 5 2) "hey" (+ 1 3)). that's exactly what's going on with []>, it only looks a bit weirder
10:53	crios	achim, I'm not sure whether your example helps :)
10:53	crios	how that help (I'm a newbe)
10:54	crios	in your example '<' evaluates to <, being just a symbol, right?
10:56	achim	yes, it evaluates to the < function. functions are values just like numbers and strings are
10:56	Chouser	,[1 2 :a :b "hello" <]
10:56	clojurebot	[1 2 :a :b "hello" #<core$_LT___4049 clojure.core$_LT___4049@dd23cf>]
10:56	achim	the body of a function can contain multiple expresssions. each of those will be evaluated, but only the result of the final one will be returned
10:57	crios	,(<)
10:57	clojurebot	java.lang.IllegalArgumentException: Wrong number of args passed to: core$-LT-
10:58	crios	where < apply here : (defn foo [] 3 5 < (+ 1 3))
10:58	liwp	,(do (+ 1 1) (+ 1 2) (+ 1 3))
10:58	clojurebot	4
10:58	liwp	crios: only the last form gets returned to the caller
10:58	AWizzArd	crios: everything is ignored, only the last form gets returned
10:58	achim	crios, it isn't applied, it's just there
10:58	liwp	i.e. (+ 1 3) -> 4
10:59	AWizzArd	,1 2 3
10:59	clojurebot	1
10:59	AWizzArd	fine :)
10:59	liwp	all the other forms get also evaluated, but the return values do not get shown to caller
10:59	crios	It is not returned, but is it evaluated?
10:59	liwp	yep
10:59	liwp	,(do (+ 1 1) (+ :a :b) (+ 1 3))
10:59	clojurebot	java.lang.ClassCastException: clojure.lang.Keyword cannot be cast to java.lang.Number
11:00	liwp	so the (+ :a :b) fails
11:00	liwp	even though its return value (3 in the previous example) did show up in the output
11:00	Chouser	did not :-)
11:00	liwp	,(do (println 1) (println 2 (+ 1 3))
11:00	clojurebot	EOF while reading
11:01	liwp	Chouser: uhh, yeah, sorry
11:01	liwp	,(do (println 1) (println 2) (+ 1 3))
11:01	clojurebot	4
11:01	clojurebot	1 2
11:01	crios	in (defn foo [] 3 5 < (+ 1 3)) , how is < evaluated ? as (< x ) ?
11:01	achim	crios: simpler example (defn foo [] 1 2) -> first 1 is evaluated, but not returned since not the final expression, then 2 is evaluated and returned
11:01	liwp	,<
11:01	clojurebot	#<core$_LT___4049 clojure.core$_LT___4049@dd23cf>
11:01	Chousuke	crios: no, just <
11:01	Chousuke	crios: it's a function, so when evaluated you get the function object
11:01	liwp	it evaluates to the function <
11:02	liwp	(let [fn <] (fn 1 2))
11:02	crios	,(doc <)
11:02	liwp	,(let [fn <] (fn 1 2))
11:02	clojurebot	"([x] [x y] [x y & more]); Returns non-nil if nums are in monotonically increasing order, otherwise false."
11:02	clojurebot	java.lang.RuntimeException: java.lang.RuntimeException: java.lang.RuntimeException: java.lang.UnsupportedOperationException: nth not supported on this type: Integer
11:02	Chousuke	crios: in fact, that's what happens even when it's (< 1 3); the < is evaluated, yielding the fn, which is then called :)
11:02	liwp	,(let [f <] (f 1 2))
11:02	clojurebot	true
11:02	achim	crios: (defn bar [] > 2) -> first "<" is evaluated (but not called!), but not returned, then 2 is evaluated and returned
11:03	crios	I would guess that the < evaluation should fail, becouse < expects twos arguments at least
11:03	Chousuke	crios: no. it's not being called
11:03	Chousuke	,(<)
11:03	clojurebot	java.lang.IllegalArgumentException: Wrong number of args passed to: core$-LT-
11:03	achim	if you don't put parentheses around a function symbol, it doesn't do anything, it's just "named". just like a number doesn't do anything
11:03	Chousuke	that fails
11:03	Chousuke	but
11:03	clojurebot	http://clojure.org/contributing
11:04	Chousuke	,<
11:04	clojurebot	#<core$_LT___4049 clojure.core$_LT___4049@dd23cf>
11:04	crios	yes,
11:04	crios	(resolve <)
11:04	crios	,(resolve <)
11:04	clojurebot	java.lang.ClassCastException: clojure.core$_LT___4049 cannot be cast to clojure.lang.Symbol
11:04	Chousuke	if just evaluating < would fail, then (apply < [1 2 3 4]) would fail as well :/
11:05	crios	good point :)
11:05	Chousuke	but really, it's no different from 5 or "foo", as a value
11:06	crios	they are just symbol...
11:06	Chousuke	crios: well, when it's evaluated it's no longer the symbol.
11:06	Chousuke	you get the function
11:08	konr_	Hmm, what's the difference between compojure and conjure? Has anyone used them?
11:09	crios	Fossi are you italian? do you know any Clojure user group in Milan area?
11:11	Fossi	more like ,(resolve '<)
11:11	Fossi	crios: no. i'm german. what makes you think i'm italian? :D
11:17	crios	your nickname is very similar to ours real surnames :D
11:18	crios	pardon anyway, fossi
11:20	raphinou_	is there a way to display the :doc of a namespace like it exists for functions doc strings?
11:21	Chousuke	,(:doc ^ns)
11:21	clojurebot	nil
11:21	Chousuke	hm. no doc for that namespace I guess.
11:21	Chouser	(doc clojure.contrib.seq-utils)
11:21	clojurebot	java.lang.ClassNotFoundException: clojure.contrib.seq-utils
11:21	Chouser	hmph. clojurebot doc is not the same as core doc
11:22	rfgpfeiffer	crios: were you at ELS?
11:22	crios	no rfgpfeiffer. What is ELS ?
11:23	rfgpfeiffer	European Lisp Symposium
11:23	crios	no
11:23	rfgpfeiffer	was in Milano this Year
11:23	Chouser	oh, I think the metadata on namespaces disappears when compiled to .class files.
11:24	crios	:( - one more problem of being a newbe in clojure!
11:24	rfgpfeiffer	everybody said "clojure is cool but i have not yet have had the time to run it"
11:24	crios	so I'm pleased to not be there! ;)
11:25	crios	to much people, in these days, like buzz / fashion words! But how many try what adulate?
11:25	Chouser	~ticket #130
11:25	clojurebot	{:url http://tinyurl.com/ndkovn, :summary "Namespace metadata lost in AOT compile", :status :new, :priority :normal, :created-on "2009-06-19T04:47:33+00:00"}
11:25	raphinou_	Chouser: (doc clojure.test) gives nil
11:32	Chousuke	raphinou_: looks like it's not documented
11:33	raphinou_	Chouser: clojure.test namespace definitely has :doc : http://github.com/richhickey/clojure/blob/270185aba54cef1d8ce59ec347b5623f2e502afe/src/clj/clojure/test.clj
11:33	stuartsierra	What Clojure tutorial should I give to CS students who know neither Lisp nor Java?
11:34	raphinou_	it's as a comment in the file and as :doc attached to ns (strange to have twit twice btw)
11:34	rfgpfeiffer	stuartsierra: timeframe?
11:34	Chousuke	hm, so the mock library went into contrib? :/
11:35	stuartsierra	rfgpfeiffer: shorter than a book, but a thorough trip through the language
11:35	stuartsierra	raphinou_: that's an artifact of when someone added metadata to the ns, copying my comments
11:37	Chousuke	hm.
11:37	Chousuke	clojure-mode syntax highlighting seems to break on mock.clj :P
11:38	raphinou_	ok
11:44	LauJensen	Anybody gearing up for the Alioth Shootout?
11:48	crios	coming for a moment (forgive me) to the expression (def [] 2 < (+ 1 2)), the < is evaluated to the fuction name by means of the fourth rule into http://clojure.org/evaluation , that is "A lookup is done in the current namespace to see if there is a mapping from the symbol to a var"
11:49	Fossi	LauJensen: i'd guess that running on a vm will alwazs slow you down compared to machinecode compiled languages :)
11:49	Fossi	so what's the point?
11:49	LauJensen	Notice Scala in the top 5 ?
11:57	Fossi	well, i guess it depends a lot on how you measure
11:57	Fossi	seems they have measurements for java with and without startup and first run
12:16	tmountain	stuartsierra: http://java.ociweb.com/mark/clojure/article.html ?
12:17	stuartsierra	tmountain: thanks, that's one I hadn't seen before
12:19	tmountain	stuartsierra: no problem. it's my go to document when introducing people to clojure
12:19	clojurebot	People have a problem and think "Hey! I'll use a regular expression!". Now they have two problems....
12:21	michael_teter	lol
15:31	crios_	,>
15:31	clojurebot	#<core$_GT___4136 clojure.core$_GT___4136@18b995c>
15:35	Chouser	crios_: exactly
15:46	crios_	,(defn foo [] > (+ 1 2))
15:46	clojurebot	DENIED
15:47	Chouser	clojurebot won't let you def stuff.
16:08	crios_	After carefully reading (I hope!) http://clojure.org/evaluation, this is my understanding:
16:08	crios_	Regarding the expression: (do > 5) => 5
16:08	crios_	'do' is a special form, which evaluates all the expressions.
16:08	crios_	> is evaluated to an instance java class, for the second rule in http://clojure.org/evaluation: "A lookup is done in the current namespace to see if there is a mapping from the symbol to a class. If so, the symbol is considered to name a Java class object". In fact, > returns an instance class of core$_GT___3996 clojure.core$_GT___3996 type:
16:09	crios_	,>
16:09	clojurebot	#<core$_GT___4136 clojure.core$_GT___4136@18b995c>
16:09	crios_	5 is evaluated to 5, and returned as the expression value.
16:09	crios_	[ah, here the GT internal class has a diffent name - implementation detail :)]
16:10	crios_	I think all Clojure should condensate into http://clojure.org/evaluation rules
16:11	crios_	:)
16:12	crios_	core$_GT___4136 clojure.core$_GT___4136 is an internal class, inside clojure.jar
16:14	hiredman	http://www.thelastcitadel.com/images/clojure.png
16:19	hiredman	not as nice as I was hoping for, since, of course, clojure.core has a very minimal ns form
16:31	crios_	what is it hiredman? an "import" visual tracking?
16:31	hiredman	it's a trawl of information from ns forms in my local checkout of clojure
16:32	crios_	how has you get it?
16:32	hiredman	http://github.com/hiredman/clojure-dependency-grapher
16:32	hiredman	it outputs stuff in the graphviz dot format
16:33	crios_	cool!
16:35	crios_	it would worth explain better, in the README file, the lib purpose :)
16:37	hiredman	the purpose is to make pretty pictures
16:38	crios_	"script reads the ns forms from clojure files in a directory and writes out a graph of dependencies"
16:38	crios_	well, I think it is very useful
16:39	crios_	every tool which can give an higher overview on the code worth the effort
16:39	hiredman	I updated the readme and pushed, just hasn't shown up on the web ui yet
16:40	crios_	have you ever seen this: http://www.visualcomplexity.com/vc/project.cfm?id=261
16:40	crios_	or this: http://www.visualcomplexity.com/vc/project.cfm?id=262
16:40	crios_	?
16:40	hiredman	I think I may have seen the first one somewhere
16:43	crios_	presenting code as art is a great effort
16:43	crios_	someone also tries to converting it into music: www.codesounding.org/indexeng.html ;)
16:44	LauJensen	~def time
16:48	danlarkin	Hello clojure folk
16:48	LauJensen	Hey Mr. Dan
16:49	danlarkin	I have a probably stupid question
16:49	danlarkin	but in my repl \u066f is coming back as \?
16:49	danlarkin	,\u066f
16:49	clojurebot	\ٯ
16:49	danlarkin	perhaps it's a factor of my environment
16:50	hiredman	do you have a font with that glyph?
16:50	hiredman	http://www.fileformat.info/info/unicode/char/066f/index.htm
16:51	hiredman	hmm
16:51	danlarkin	hiredman: yeah it's not the font
16:52	hiredman	clojurebot: logs?
16:52	clojurebot	logs is http://clojure-log.n01se.net/
16:52	Chousuke	funky
16:52	Chousuke	iTerm renders that character before the \...
16:53	hiredman	http://clojure-log.n01se.net/date/2009-09-12.html#19:28 <-- hard to follow because the logger doesn't handle utf8
16:53	hiredman	user=> (.getEncoding out)
16:53	hiredman	"Cp1252"
16:53	hiredman	user=>
16:53	hiredman	:(
16:54	danlarkin	Hmmm mine is MacRoman
16:55	hiredman	,(.getEncoding out)
16:55	clojurebot	java.lang.IllegalArgumentException: No matching field found: getEncoding for class java.io.StringWriter
16:55	hiredman	oh, right
16:55	crios_	probably also a System.out.println("\u066f") in plain old Java does not output the arabic char, doesnt'it?
16:57	danlarkin	crios_ correct, just tried it and I get a ? back from java
16:59	hiredman	the -Dfile.encoding=UTF8 seems to do the trick
16:59	hiredman	if you have a UTF8 locale setup it seems to default to UTF8 anyway
17:00	crios_	,(System/getProperty "file.encoding")
17:00	clojurebot	java.security.AccessControlException: access denied (java.util.PropertyPermission file.encoding read)
17:01	crios_	confirm hiredman
17:01	crios_	here user=> (System/getProperty "file.encoding") => "UTF-8"
17:01	crios_	java defaults to the OS charset
17:02	crios_	unless you use -D
17:02	crios_	BTW: http://www.websina.com/bugzero/kb/java-encoding-charset.html
17:04	crios_	logs?
17:04	crios_	clojurebot: logs?
17:04	clojurebot	logs is http://clojure-log.n01se.net/
17:11	danlarkin	well so that's pretty annoying
17:12	danlarkin	I don't think I can change my default encoding on a OS X
17:12	Chousuke	hm
17:12	Chousuke	there should be a way to set systemwide properties
17:14	hiredman	http://www.rift.dk/news.php?item.7.6
17:14	hiredman	http://developer.apple.com/mac/library/documentation/Darwin/Reference/ManPages/man1/locale.1.html
17:15	crios_	yes there is: java -Dfile.encoding=UTF-8
17:16	crios_	starts your REPL with such property
17:16	crios_	it should work
17:16	hiredman	if osx still uses bsd's setup stuff, there is always .login_conf
17:17	hiredman	http://gist.github.com/186934
17:19	crios__	IMHO you can change just the JVM property , not the whole OS configuration
17:19	danlarkin	crios_: I don't want to set it every time
17:19	danlarkin	and in every place I launch the jvm
17:19	hiredman	and everything should be set for utf-8 anyway
17:20	crios__	as you like :) just saying what suffice
17:24	danlarkin	well I have set LANG and LC_ALL to en_US.UTF-8 and still java has my file.encoding as MacRoman
17:24	danlarkin	I am annoyed because it did not used to be this way
17:24	danlarkin	I noticed this because of a test failing... but it used to pass
17:24	hiredman	hmmm
17:25	hiredman	are you sure the LANG variables are set?
17:26	danlarkin	Tarragon:~ dan$ echo $LANG, $LC_ALL
17:26	danlarkin	en_US.UTF-8, en_US.UTF-8
17:27	Chousuke	there's the environment.plist thing. what about that? :)
17:28	technomancy	Chousuke: when all else fails, edit an XML file!
17:28	technomancy	~xml
17:28	clojurebot	It's greek to me.
17:28	Chousuke	technomancy: and then the rest will fail too
17:28	technomancy	~xml is like violence; if it's not working, you're not using enough of it.
17:28	clojurebot	'Sea, mhuise.
17:30	Chousuke	hm, no wonder it's popular then
17:30	hiredman	~XML
17:30	clojurebot	XML is like violence; if it doesn't solve your problems, you're not using enough of it.
17:30	Chousuke	people are generally attracted to violence
17:30	Chousuke	as long as it's someone else.
17:31	hiredman	the switch to a derby backend should also take care of case sensitivity issues
17:31	technomancy	hiredman: nice; it echoes in the same case as you use in the query
17:31	hiredman	technomancy: no :( there are just two factions, XML and xml
17:31	hiredman	the XML one already there
17:31	Chousuke	clojurebot uses a real database now?
17:31	hiredman	not yet
17:32	hiredman	it's on my list of things todo
17:32	Chousuke	~XmL is case-sensitive
17:32	clojurebot	You don't have to tell me twice.
17:33	technomancy	oh; hah
17:33	technomancy	I think I added the all-caps one too.
17:35	hiredman	you did, in July
17:36	technomancy	great minds think alike!
17:42	Chouser	~exceptions
17:42	clojurebot	http://paste.lisp.org/display/74305
17:42	Chouser	perfect!
17:43	Chouser	hm. could be sorted.
17:45	crios__	what is pastelisp?
17:46	hiredman	lisppaste8: url?
17:46	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
17:47	crios__	is it a sort of paste bin?
17:47	futuranon	crios__: yes
17:47	crios__	ah
17:48	hiredman	it's a neat pastbin, because it comes with an irc bot
17:50	lisppaste8	crios pasted "try" at http://paste.lisp.org/display/87068
17:51	crios__	cool :)
17:51	crios__	how do you use it? to share code?
17:52	hiredman	to paste examples and problems
17:52	Chousuke	I don't like the lisp pastebin though. it doesn't colourise the source properly :(
17:52	Chousuke	I prefer gists
17:53	hiredman	http://paste.lisp.org/list/clojure
17:53	hiredman	http://delicious.com/clojurebot/pastbin
18:18	crios__	is there an ANTLR grammar for Clojure? http://code.google.com/p/clojure-antlr-grammar/ seems empty
18:18	crios__	clojurebot: logs?
18:18	clojurebot	logs is http://clojure-log.n01se.net/
18:27	stuartsierra	crios__; there's an old version somewhere in the google code SVN that Rich Hickey started and abandoned.
18:29	crios__	abandoned? why?
18:31	Chousuke	that grammar doesn't seem that old. only about 6 months :P
18:31	Chousuke	the one on the page you posted.
18:33	crios__	have you checkout the code? http://code.google.com/p/clojure-antlr-grammar/downloads/list is empty
18:33	hiredman	http://code.google.com/p/clojure-antlr-grammar/source/browse/
18:33	crios__	ah ok
18:33	crios__	http://code.google.com/p/clojure-antlr-grammar/source/browse/src/Clojure.g
18:33	crios__	yes
18:34	beutdeuce	I have a question regarding clojure and maven. i ran mvn install and a jar file was created successfully;however, I am having trouble running the jar file. Can anyone help as to what I can do to successfully run that jar file?
18:35	hiredman	define trouble
18:35	beutdeuce	no class def found. no main class found
18:35	hiredman	what is inside the jar?
18:36	beutdeuce	does it matter? Canit i use -cp ?
18:36	hiredman	well, if the classes are not inside the jar, that would explain why there is no class def found
18:37	beutdeuce	doesnt mvn install package the classes into the jar automatically?
18:37	beutdeuce	i can check whats inside anyway
18:37	beutdeuce	h/o
18:37	hiredman	a jar file is just a zip file
18:37	beutdeuce	i know
18:38	hiredman	I have no idea, I've never used maven
18:38	hiredman	so unzip it
18:38	beutdeuce	k, there is META_INF, and there is clojureworld. Inside clojureworld, there is main__init.class and main$main__1.class
18:39	technomancy	beutdeuce: the maven build of clojure is not very well-supported
18:39	technomancy	if you just want to build the jar, try ant instead
18:39	crios__	does that grammar is used to generate the Clojure runtime reader?
18:39	beutdeuce	technomancy: perhaps, but it is required for the project I'm working on (altlaw) to use it
18:39	hiredman	beutdeuce: that's not right
18:40	beutdeuce	hiredman: ?
18:40	hiredman	the clojure.jar should have more inside then that
18:40	technomancy	beutdeuce: do you need 1.0 or 1.1-SNAPSHOT?
18:40	technomancy	you can use one of the forks we have at work that fix the pom file
18:40	beutdeuce	technomancy: ? i'm just having trouble building a clohure program i wrote with mvn, I'm fine with lcojure itself
18:41	beutdeuce	I just need help as to how i can run the jar file created by maven
18:41	technomancy	http://github.com/sonian/clojure/tree/1.0.x
18:42	beutdeuce	i take it that is the clojure repo?
18:42	technomancy	it's a fork of it that fixes the pom file so it will work with mvn install, yes
18:43	beutdeuce	but im not having trouble with maven install
18:43	beutdeuce	i create my own clojure program using mvn called clojureworld which is basically a hello world application
18:43	beutdeuce	im trying to compile it with mvn into a jar file
18:43	technomancy	sorry; misread the question
18:43	beutdeuce	which succeeded. My problem is running the jar file
18:43	beutdeuce	np
18:44	hiredman	lisppaste8: url
18:44	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
18:44	hiredman	paste the exception
18:44	hiredman	and your classpath
18:44	hiredman	and how
18:45	hiredman	you are attempting to run the jar
18:45	beutdeuce	l
18:47	beutdeuce	k
18:48	lisppaste8	beutdeuce pasted "untitled" at http://paste.lisp.org/display/87070
18:49	hiredman	~compile
18:49	clojurebot	the unit of compilation in clojure is the namespace. namespaces are compiled (not files). to compile a namspace the namespace needs to be on the classpath and so does ./classes/ (and the directory needs to exist) because clojure writes the class files to that directory. http://clojure.org/compilation
18:50	hiredman	http://clojure.org/API#gen-class <-- I'd read what it says about prefixes
18:50	hiredman	and I recomend using defn there instead of def
18:54	beutdeuce	hmm
18:54	beutdeuce	now i get a different error
18:54	lisppaste8	beutdeuce pasted "Error" at http://paste.lisp.org/display/87071
18:56	hiredman	beutdeuce: paste your new main.clj file
18:56	beutdeuce	(ns clojureworld.main
18:56	beutdeuce	(:gen-class))
18:56	beutdeuce	(defn -main
18:56	beutdeuce	[args]
18:56	beutdeuce	(println "Hello World"))
18:57	beutdeuce	thnx to :gen-class, i know have a main.class class in my jar, but when i run clojureworld.main, i get an iFn no class found error
18:57	beutdeuce	which is the Fn
18:57	beutdeuce	im not sure why
18:58	hiredman	pastebin updates of all teh previous information: the exception, the classpath, and how you are runing the jar
18:59	beutdeuce	its all the same
18:59	hiredman	…
18:59	hiredman	you just said the exception is different
18:59	beutdeuce	i just pasted it
18:59	beutdeuce	http://paste.lisp.org/display/87071
18:59	beutdeuce	thats all that changed
18:59	hiredman	and how are you trying to execute the jar?
19:00	beutdeuce	java -cp target/clojureworld.jar clojureworld.main
19:00	hiredman	well, clojure needs to be on the classpath too
19:04	beutdeuce	how do i specify multiply classpaths in -cp ?
19:04	technomancy	beutdeuce: colon-separated list of jar files on unix
19:05	beutdeuce	still get the latest error
19:05	beutdeuce	Exception in thread "main" java.lang.NoClassDefFoundError: clojure/lang/IFn
19:05	hiredman	lets see your new command line
19:05	beutdeuce	ava -cp target/clojureworld-1.0-SNAPSHOT.jar:~/.clojure/clojure.jar clojureworld.main
19:06	hiredman	you cannot use ~ there
19:06	beutdeuce	oh? has to be fully-qualified?
19:06	technomancy	use $HOME
19:06	beutdeuce	k
19:06	hiredman	$HOME or $PWD
19:07	beutdeuce	k, works now. Thanks! But its weird. the clojure.jar file is in my $CLASSPATH but apparently it doesnt detect it?
19:07	hiredman	-cp negates $CLASSPATH
19:07	hiredman	one or the other
19:07	beutdeuce	ah
19:07	beutdeuce	got it
19:07	beutdeuce	thanks!
19:09	beutdeuce	huh, why does it take 1.4 seconds to run?
19:09	hiredman	jvm start up time
19:10	beutdeuce	very time java is called, jvm restarts?
19:10	hiredman	java = jvm
19:10	beutdeuce	k
19:10	beutdeuce	thanks
19:11	beutdeuce	oh, and why would u use defn rather than def ?
19:11	hiredman	,(defn def)
19:11	clojurebot	DENIED
19:12	hiredman	clojurebot: thanks!
19:12	clojurebot	Huh?
19:12	Chousuke	beutdeuce: defn has better syntax.
19:12	hiredman	defn is specifically for defining functions
19:12	Chousuke	(defn main [] foo) instead of (def main (fn [] foo))
19:12	hiredman	and it has all kinds of doo-dads
19:12	hiredman	like docstrings
19:12	Chousuke	and it supports doc.. yes.
19:12	Chousuke	it also expresses your intent better than def. :)
19:13	beutdeuce	ok
19:13	Chousuke	and in the end it expands to (def ...) but you need not care about that.
19:13	beutdeuce	even though it is used several times through the doc
19:13	hiredman	which docs?
19:13	beutdeuce	clojure.org
19:14	hiredman	be more specific
19:14	hiredman	there is a lot on clojure.org
19:14	beutdeuce	http://clojure.org/special_forms
19:15	hiredman	it's only used there twice, and once is part of an example of the fn special form
19:16	beutdeuce	k
19:17	Chousuke	there's nothing wrong with using def for fns of course
19:17	hiredman	(but don't)
19:18	beutdeuce	k
19:18	Chousuke	just like there's nothing wrong with walking barefoot even though you have shoes :P
19:18	beutdeuce	so, defn is more efficient in some way?
19:18	Chousuke	for the programmer it is.
19:18	beutdeuce	k
19:19	Chousuke	it reduces clutter and the intent is clearer.
19:19	beutdeuce	k
19:19	hiredman	I mean, you could just wrap your program in side a single large fn
19:20	hiredman	,((fn [f g] (f (g 1 2) 3)) (fn [x y] (+ x y)) (fn [x y] (* x y*)))
19:20	clojurebot	java.lang.Exception: Unable to resolve symbol: y* in this context
19:20	hiredman	,((fn [f g] (f (g 1 2) 3))) (fn [x y] (+ x y)) (fn [x y] (* x y*)))
19:20	clojurebot	java.lang.IllegalArgumentException: Wrong number of args passed to: sandbox$eval--2860$fn
19:20	hiredman	bah
19:20	hiredman	I really need paren balancing irc
19:20	Chousuke	:P
19:21	Chousuke	erc with paredit!
19:21	Chousuke	no more mismatched parentheses!
19:21	hiredman	,((fn [f g] (f (g 1 2) 3)) (fn [x y] (+ x y)) (fn [x y] (* x y)))
19:21	clojurebot	5
19:21	hiredman	no def at all
19:23	Chousuke	,((fn [f g] (f (g 1 2) 3)) * +); one wonders why you didn't just do this :P
19:23	clojurebot	9
19:24	Chousuke	(other way around though :))
19:24	hiredman	Chousuke: because I was demonstrating the binding of Fns to names without using def
19:25	hiredman	now granted that does the samething, but it is less obvious that a fn is being bound, because you only see the one fn on the lef there
19:25	Chousuke	I suppose
19:26	hiredman	clearly an exercise in tom foolery
19:27	hiredman	have you seen http://www.thelastcitadel.com/images/clojure.svg ?
19:27	Chousuke	,((fn this [f] (f this)) (fn this [f] (f this))); more funky stuff
19:27	clojurebot	java.lang.StackOverflowError
19:27	Chousuke	that's like putting two mirrors against each other
19:28	hiredman	,((fn [x y] (x y)) (fn [x y] (x y)))
19:28	clojurebot	java.lang.IllegalArgumentException: Wrong number of args passed to: sandbox$eval--2909$fn
19:28	hiredman	bah
19:29	hiredman	,((fn [x] (x x)) (fn [x] (x x)))
19:29	clojurebot	java.lang.StackOverflowError
20:32	manic12	how do you do a return-from ?
20:33	dnolen`	manic12: no such thing as far as I know.
20:34	manic12	ok
20:34	Chousuke	you can throw an exception :)
20:34	Chousuke	(and then you can stop coding :P)
20:34	dnolen`	manic12: i did a little experiment on how you can have arbitrary control with an exception on the mailing, and even returning a value.
20:34	dnolen`	manic12: as long as the exception is created ahead of time, it won't be slow.
20:35	dnolen`	this is again a hack.
20:35	dnolen`	you should figure out how to solve your problem in a different way.