#clojure – 2010-01-20

2010-01-20

00:09	replaca	new rule proposal: projects written in Clojure may not have the letter "j" in their names
00:10	technomancy	replaca: yes please!
00:11	technomancy	that cocoa bridge had a name that just made me cringe
00:12	defn`	i like the ji thing
00:12	defn`	like djirk
00:15	technomancy	personally I'm naming all my projects after literary characters from now on
00:17	alexyk	technomancy: how about I sing praises for leiningen every day for 5 days if you add host to lein swank in addition to port tmrw? :)
00:17	replaca	I think I'll go for the dullest possible names
00:18	replaca	starting with "autodoc"
00:18	technomancy	alexyk: you could spend the time you would potentially spend singing praises to write the code. =)
00:18	replaca	which would be pretty cool if it took out your appendix, but less so with the whole html generation thing
00:18	alexyk	technomancy: I don't know where to begin, macros scare me
00:19	alexyk	plus I don't know swank and where the host would need to be stuck/plucked from
00:19	alexyk	I'd rather stick to my core competency of singing and let you add it :)
00:19	technomancy	heh
00:19	defn`	my core competency is witchcraft
00:20	technomancy	alexyk: the swank server binds to more than just localhost for me
00:20	alexyk	defn: don't you have to be a witch to practice it?
00:20	technomancy	did you want to limit it to just localhost?
00:20	alexyk	technomancy: no, I don't see it binding to the external IP. Hmm.
00:20	alexyk	I actually wanted to have a host to explicitly tell it to bind there.
00:20	defn`	alexyk: i havent gotten that far yet
00:21	alexyk	defn: I never heard of male witches either
00:21	technomancy	alexyk: binding to 0.0.0.0 should work for all active interfaces
00:21	replaca	technomancy: is the sonian crew going to brave the tsunami and come to functional alcoholics tomorrow?
00:22	alexyk	technomancy: does it try to bind to 0.0.0.0 by default?
00:22	technomancy	replaca: that's the plan
00:22	technomancy	alexyk: seems to here
00:22	alexyk	hmm
00:22	replaca	technomancy: cool. looking forward to it.
00:23	replaca	it'll be fantastic not to be the only clojure guy there
00:23	technomancy	replaca: we should outnumber the scala guys this time. =)
00:23	technomancy	replaca: how many attend total normally?
00:23	replaca	technomancy: especially since we seem to be converting al3x
00:23	replaca	30-40
00:23	technomancy	wow!
00:23	technomancy	seafunc is 5-6
00:23	alexyk	say I'm carrying around a tortured Java object. To mimic FP, I have defns like, (defn doGraph [graph] ... graph). Will it copy the graph, or, it being a Java object, pass references around?
00:23	replaca	we take our tech seriously by the bay :-)
00:24	replaca	does seafunc involve beer?
00:24	alexyk	replaca: it used to
00:24	technomancy	it varies. I'm sure that affects things.
00:24	replaca	that seems to be what brings them out
00:24	technomancy	also it only happens 4 or 5 times a year, which is lame
00:25	technomancy	alexyk: you've been?
00:25	alexyk	technomancy: yep
00:25	replaca	there used to be bayfp, too, which was more serious. But I don't think they've had one in a while
00:25	technomancy	alexyk: you in the area?
00:25	alexyk	a series of bearded and unbearded folks, the great FP ones, in University City or Capitol Hill... a couple years ago, alas.
00:26	wooby	anyone ever run across clojure jobs in the bay area?
00:26	technomancy	I'm thinking about having a Seattle Clojure meeting next month
00:26	technomancy	got 5 already interested
00:26	alexyk	I visit when giving a talk at MSFT once in a while
00:27	alexyk	or visiting my friends in the area
00:27	alexyk	technomancy: amazing, for clojure
00:27	alexyk	so what about accepting and returning a Java object in a defn, does it copy or hopefully not?
00:28	technomancy	it won't copy unless you explicitly do it
00:28	alexyk	good
00:28	replaca	technomancy: I think I may have had the honor of hosting the biggest pure clojure meetup ever
00:28	replaca	(to date that is)
00:29	replaca	when Rich came to SF and we had the bay area group meeting
00:30	technomancy	replaca: yeah, I made it for that one
00:30	technomancy	very exciting
00:31	joegg	technomancy: what you mean "explicity do it", regarding the copy?
00:32	joegg	As in (.clone foo)? Or am I missing something?
00:32	technomancy	joegg: that's what I meant, yeah
00:32	technomancy	there's no auto-immutablize
00:32	replaca	technomancy: I remember - a good crowd, but too much for the space
00:32	technomancy	standing room only
00:32	joegg	technomancy: Thanks, just wanted to make sure I hadn't missed something big.
00:34	alexyk	I'm running clojure under rlwrap and suddenly see rlwrap at 100% CPU all the time, and Java at 50-150% (8 cores). Is there a reason why rlwrap would hog CPU?
00:40	TheBusby	is there an easy way to rebind in to a file for testing in slime?
01:42	rikthevik_	i want to write a pipeline function . it takes functions a, b, c and an initial value then calculated (c (b (a initial)))
01:42	rikthevik_	thoughts?
01:42	rikthevik_	i did it lisp-style using pop and peek, but it's not working great when the list of functions is a seq
01:46	TheBusby	rikthevik I think there is already something similiar, like ->>
01:46	TheBusby	or -->
01:46	TheBusby	one of the arrows I believe
01:47	TheBusby	good luck googling for it though...
01:50	TheBusby	,(doc ->>)
01:50	clojurebot	"([x form] [x form & more]); Threads the expr through the forms. Inserts x as the last item in the first form, making a list of it if it is not a list already. If there are more forms, inserts the first form as the last item in second form, etc."
02:20	konr`	What's the best way to represent a file? Is it a good idea to stick with Java's IO classes, or it's fine to create some convention for my function, like a PATH starting with @ denotes a file?
02:25	technomancy	konr`: I generally represent it as a string until I need to call file-related functions/methods on it
02:26	technomancy	konr`: c.c.java-utils/file is great for that; it will turn its argument into a file whether it's a string or already a file object
03:19	quizme	if you make something a ref, does that mean it's going to use another thread when possible?
03:21	technomancy	quizme: refs just have values; they don't represent computation
03:21	technomancy	maybe you're thinking of agents?
03:21	quizme	conversely, if you don't use a ref, atom, etc., does that mean it's NOT going to use another thread?
03:21	quizme	um
03:21	quizme	i dunno
03:21	quizme	just general confusion i think
03:22	quizme	i guess i'm wondering: what is it about clojure that makes it inherently more multi-CPU friendly?
03:23	defn`	it's functional
03:23	defn`	no side effects
03:23	quizme	and: are there any language constructs that let you control the threads.... (ok agents is one)
03:23	quizme	functional => all CPUs will be used?
03:23	defn`	agents, refs, atoms
03:24	defn`	quizme: no. http://en.wikipedia.org/wiki/Functional_programming
03:24	quizme	what does function programming have to do with multi-CPU friendliness?
03:24	defn`	functional as in, functions are first class
03:24	quizme	functional*
03:25	defn`	quizme: watch http://www.vimeo.com/8426709
03:25	quizme	i'm just trying to make the connection between the language and being able to use all the CPUs
03:25	defn`	quizme: you're not going to do it by making wild guesses
03:26	defn`	it's false in the first place to say "use all the CPUs"
03:26	defn`	because A.. we're talking about cores, and B.. you can use all of the CPUs in any old language
03:27	defn`	cores
03:27	quizme	ok cores
03:29	defn`	quizme: what other languages have you worked with?
03:30	quizme	scheme, c, c++, java, ruby, php, as3, javascript
03:30	defn`	and you don't understand how functional programming solves many of the problems of concurrency?
03:31	quizme	no
03:31	defn`	have you written applications with locks in c?
03:31	quizme	no
03:31	quizme	no to both questions
03:32	defn`	what does functional programming mean to you?
03:33	quizme	function behavior only depends upon the arguments
03:33	defn`	which means...no side effects
03:34	quizme	yah
03:34	defn`	which makes concurrency easier
03:34	quizme	so what does that have to do with cores ?
03:34	defn`	in a non-functional style you have to be worried about what other objects any given function/method is touching
03:36	quizme	ok
03:37	defn`	quizme: do you see how that makes scaling cores easier?
03:38	quizme	if two cores are processing the same data at the same time, you know that the action of one function won't affect the behavior of another function?
03:40	defn`	let's call them threads
03:41	quizme	so
03:41	defn`	quizme: the software transactional memory is important here
03:41	quizme	if you want to increment x
03:42	quizme	like in Lau's vimeo link you gave me
03:42	defn`	mmhm
03:42	quizme	actually
03:42	quizme	it's better to use a lazy sequence instead of atoms and all that ?
03:42	defn`	they're for different things
03:42	quizme	cuz a lazy sequence is immutable
03:42	defn`	,(doc atom)
03:42	clojurebot	"([x] [x & options]); Creates and returns an Atom with an initial value of x and zero or more options (in any order): :meta metadata-map :validator validate-fn If metadata-map is supplied, it will be come the metadata on the atom. validate-fn must be nil or a side-effect-free fn of one argument, which will be passed the intended new state on any state change. If the new state is unacceptable, the validate-fn should return
03:42	quizme	yes? no?
03:43	defn`	you need to read more before you will have a clear picture
03:43	defn`	atoms and lazy seqs aren't even close to related for the purposes of this discussion
03:47	quizme	let's say you didn't have any mutable data
03:48	quizme	how do you know if you program is going to use multiple cores or not?
03:48	quizme	just because your program is functional and processing immutable doesn't mean it's parallelizable.
03:49	quizme	immutable data i mean
05:32	lpetit	clojurebot: seen cgrand
05:32	clojurebot	cgrand was last seen quiting IRC, 274 minutes ago
05:35	esj	clojurebot you stalker
05:39	pao	clojurebot: (take 1 (filter zero? (concat (take 10 (repeat 1)) [0] (repeat 1)))
05:39	pao	hmmm
05:39	pao	why does this doesn't terminate?
05:43	pao	clojurebot: (first (filter zero? (concat (take 10 (repeat 1) [0] (repeat 1))))
05:43	esj	i think because of the filter
05:43	pao	esj: missing parens
05:44	pao	clojurebot: (first (filter zero? (concat (take 10 (repeat 1)) [0] (repeat 1))))
05:44	esj	it never gets a non-zero value
05:44	pao	esj: there a zero value
05:44	pao	*there is
05:44	pao	(first (filter zero? (concat (take 1000 (repeat 1)) [0] (repeat 1))))
05:44	esj	after an infinite number of 1s, no ?
05:44	pao	clojurebot: (first (filter zero? (concat (take 1000 (repeat 1)) [0] (repeat 1))))
05:45	pao	esj: no, after 10 1s
05:45	esj	hmm....
05:45	pao	1000 in this case
05:45	pao	esj: to you know how to query clojure version?
05:45	pao	it was a parenthesis problem, now on my machine it runs
05:46	esj	when the REPL starts it says
05:46	pao	esj: I was wondering about clojurebot's clojure version
05:46	esj	dunno :)
05:46	pao	esj: no prob :-)
05:47	pao	clojurebot: (take 10 (repeat 1))
05:47	pao	clojurebot: > (+ 1 1)
05:47	pao	clojurebot: help
05:47	clojurebot	http://www.khanacademy.org/
05:48	unfo-	not the khan i was expecting
05:48	pao	> (+ 1 1)
05:48	esj	you expecting designs for a nuke ?
05:48	unfo-	nope
05:48	pao	(+ 1 1)
05:48	clojurebot	2
05:49	pao	(take 10 (repeat 1))
05:49	esj	hahahah, missing parens !
05:49	pao	I guess it doesn't print seq...
05:49	pao	(first (take 10 (repeat 1)))
05:49	unfo-	esj, http://www.khaaan.com/
05:49	esj	(take 1 (filter zero? (concat (take 10 (repeat 1)) [0] (repeat 1))))
05:49	esj	,(take 1 (filter zero? (concat (take 10 (repeat 1)) [0] (repeat 1))))
05:49	clojurebot	(0)
05:50	pao	esj: what's the comma for?
05:50	esj	to ask clojurebot to execute the command :)
05:50	pao	esj: ah ok :-)
05:50	esj	np
05:50	pao	,(take 10 (repeat 1))
05:50	clojurebot	(1 1 1 1 1 1 1 1 1 1)
05:50	pao	nice :-)
05:51	esj	clojurebot is very friendly, for a stalker.
05:51	pao	esj: LOL
06:03	talios	Morning
06:04	AWizzArd	Hi tal
06:05	talios	mm been ages since I've fired up linkinus and lurked on IRC
06:07	Chousuke	,clojure-version
06:07	clojurebot	{:interim true, :major 1, :minor 1, :incremental 0, :qualifier "master"}
06:07	Chousuke	hmmh.
06:25	esj	now I know, thanks.
06:47	vu3rdd	given a sequence, is there a way to extract the elements from the first to last-but-one and the last?
06:47	vu3rdd	that is, first/rest but on a reversed list?
06:47	vu3rdd	(doc reverse)
06:47	clojurebot	"([coll]); Returns a seq of the items in coll in reverse order. Not lazy."
06:48	cypher23	(doc butlast)
06:49	clojurebot	"([coll]); Return a seq of all but the last item in coll, in linear time"
06:49	cypher23	(doc last)
06:49	clojurebot	"([coll]); Return the last item in coll, in linear time"
06:49	cypher23	vu3rdd, ^
06:49	vu3rdd	cypher23: thakns
06:49	vu3rdd	thanks
07:26	dabd	I don't see much use for the predicate empty? since (not (empty? is discouraged as it involves a double negation. So why not remove it and simply use (not (seq and (seq insted?
07:33	LauJensen	dabd, empty? for testing true/false, seq and not-empty for nil/coll
07:56	dabd	what is the alternative for the #^ reader macro?
09:20	kiuma	hello
09:20	kiuma	is there a library to print html code ?
09:20	chouser	kiuma: hi!
09:20	chouser	(println "<html></html>") ;-)
09:20	LauJensen	kiuma: Compojure is a good bet
09:20	kiuma	:/
09:21	LauJensen	(html [:h1 "Hello Html"])
09:21	chouser	kiuma: I guess it depends on what you're starting with.
09:22	chouser	If you have designer-created html that you want to adjust, I'd recommend enlive
09:22	kiuma	chouser, I created CLAW that is in common lisp
09:23	kiuma	a claw html renderer is similar to cl-html
09:24	kiuma	it transforms something like (div> (span> "foo")) to <div><span>foo</span></div>
09:24	kiuma	does already exist something similar in clojure ?
09:25	chouser	kiuma: ah. yeah, compojure has a lib for doing things roughly like that. something roughly like that has be written several times in clojure
09:25	cemerick	ouch
09:25	cemerick	kiuma: give enlive a try http://wiki.github.com/cgrand/enlive/
09:25	kiuma	ok htx
09:25	chouser	usually the clojure ones use keywords and vectors, so something like [:div [:span "foo"]]
09:28	kiuma	chouser, so I only should implement a parser, right ?
09:29	cemerick	kiuma: are you aiming to create another templating library?
09:29	chouser	kiuma: an html parser? there are good ones available already.
09:30	kiuma	Id like something that is the most similar to html
09:30	dabd`	if the ^ read macro is deprecated in 1.1 what will substitute #^ ?
09:30	chouser	dabd`: eventually, yes.
09:30	cemerick	dabd`: I think with-meta will be required
09:31	chouser	oh, sorry, misunderstood. #^ has not been deprecated
09:31	cemerick	oh, I thought it was :-/
09:31	cemerick	kiuma: it's worth using existing libs unless there's something compelling to build separately.
09:31	cemerick	some compelling reason, I mean
09:32	cgrand	kiuma: enlive is so similar to html that it's html ;-)
09:32	chouser	there's nothing else that will work in place of #^, though I guess ^ will eventually
09:32	dabd`	so only ^ will be deprecated
09:32	cemerick	cgrand: I've been trying to soft-pedal it ;-)
09:32	seths	kiuma: if you need to generate Javascript easily consider http://github.com/arohner/scriptjure/
09:32	Hali_303	hi! In Emacs/SLIME, when I try it the repl or do a compilation it hangs. how to find out what is the trouble?
09:33	cgrand	cemerick: I noticed your efforts :-)
09:33	seths	Hali_303: can you switch to the inferior-lisp buffer?
09:33	Hali_303	seths, yes
09:33	seths	you should hopefully see something like
09:33	seths	user=> user=> Connection opened on local port 49318
09:33	seths	#<ServerSocket ServerSocket[addr=0.0.0.0/0.0.0.0,port=0,localport=49318]>
09:33	kiuma	seths, javascript must be done in javascript
09:33	Hali_303	seths: yes, that is there
09:34	kiuma	and not in html pages
09:34	dabd`	sorry to repeat the question but what is the use of the empty? predicate if (not (empty? is discouraged because of the double negation? Why not remove empty? and simply use (not (seq and (seq instead?
09:34	Hali_303	seth: also, below that: user=> user=> WARNING: reader macro ^ is deprecated; use meta instead
09:34	Hali_303	WARNING: reader macro ^ is deprecated; use meta instead (
09:34	kiuma	this beacause it avoid compression in any other language
09:34	cemerick	dabd`: (not (empty?)) is discouraged?
09:35	seths	kiuma: sure, but Scriptjure is pretty slick: (js (alert "hello world")) => "alert(\"hello world\")"
09:35	chouser	dabd`: (not (seq x)) is less clear than (empty? x)
09:35	cemerick	cgrand: I'm almost to the point of knowing what I'm doing with enlive :-) It's quite pleasant.
09:35	seths	Hali_303: hmm, it sounds like swank is running then
09:35	dabd`	cemerick if you read the documentation it recommends avoiding (not (empty? and use the idiom (seq instead
09:36	Hali_303	seths, when I type (+ 1 2) I can see that parentheses-matching is also working, but if I press enter after that, it hangs
09:36	cgrand	cemerick: I'm happy to hear that!
09:36	dabd`	chouser: but (seq x) is also less clear than (not (empty? x)). At least for me...
09:36	cemerick	dabd`: I'd say either is fine -- many people (myself included) like a 'literate' style, where the semantics of empty? are helpful
09:36	kiuma	seths, compression -> http://www.wingstech.it/claw/dojotoolkit/dojo/dojo.js
09:36	dabd`	cemerick: yes. I appreciate that too
09:38	seths	Hali_303: hrm.
09:38	chouser	mutliple negatives are more difficult to think about than simple positives.
09:38	cemerick	cgrand: the only thing I need to figure out is how to structure things properly. "normal" templating languages allow you to segment code pretty naturally based on one's layout -- that not being available means one has to figure out how to compose various transformations for each page, etc.
09:38	seths	Hali_303: how was swank-clojure installed?
09:38	fogus	chouser: That is not not not not true
09:39	ordnungswidrig	(def full (comp not empty?))
09:39	cemerick	chouser: empty? is a predicate, and doesn't imply a negation.
09:39	dabd`	chouser: but when you use (not (empty? x)) the multiple negative is hidden in the implementation of empty? right?. For the user there is only one negation.
09:39	chouser	cemerick: right. so say (empty? x) instead of (not (seq x))
09:40	chouser	cemerick: but also, say (seq x) instead of (not (empty? x))
09:40	Hali_303	seths: checked out into a directory as described here: http://riddell.us/tutorial/slime_swank/slime_swank.html
09:41	cemerick	chouser: the fact that empty? is implemented using a negation is an implementation detail, IMO, and shouldn't influence coding style shrug
09:41	ordnungswidrig	cemerick: hehe
09:41	chouser	sorry, let me amend my statement. any negation is harder to think about that simple positive statements
09:41	cemerick	consider an alternate universe where seq returns an ISeq instead of nil for empty, and provided an .isEmpty() method.
09:42	cemerick	even more to the point, what about if/when empty? becomes a protocol, totally divorced from seqs?
09:42	somnium`	(when-let [s (seq arg)] ...) seems more elegant than (when-let [s (not (empty? arg))] ...)
09:42	fogus	chouser: I !disagree
09:43	cemerick	heh
09:43	seths	Hali_303: another option is to use leiningen
09:43	cemerick	fogus: go away with your algolisms! :-P
09:43	fogus	cemerick: (not :))
09:43	ordnungswidrig	offline...
09:44	Raynes	fogus. He disagrees.
09:44	seths	create a project, add [leiningen/lein-swank "1.0.0-SNAPSHOT"] to the :dev-dependencies
09:44	seths	and then run swank-clojure-project
09:44	seths	has been the smoothest process for me
09:44	Hali_303	seths: ok, I'll look into that, thanks
09:44	seths	g/l
09:50	cgrand	cemerick: I've been experimenting with layout as middlewares. In such a setting the :body of the response is a map whose vals are html fragments.
09:51	seths	does anyone know if clojure-mode has been updated for deftype?
09:51	seths	when I'm defining a method inside a deftype, clojure-mode indents like I'm calling the function
09:52	seths	since there is no defn or similar keyword
09:52	AWizzArd	at least jochu’s repositories were not updated for months
09:53	cemerick	cgrand: I'm afraid I can't visualize that right off the bat.
09:53	cemerick	cgrand: I've been toying with identifying + looking up transformations based on element id's in the template/snippet.
09:53	Hali_303	seths: it seems that slime was also installed as an ubuntu package and that did not like the one installed manually. working now, thanks!
09:54	seths	Hali_303: glad to hear it's working, not that I did anything really :-)
10:09	seths	,(with-meta "foo" {:bar 'baz})
10:09	clojurebot	java.lang.ClassCastException: java.lang.String cannot be cast to clojure.lang.IObj
10:09	seths	:-(
10:09	seths	I'm being idealistic I suppose
10:10	angerman	seths: there's nothing that keeps you from adding meta support to your own string type
10:12	cemerick	where do plans stand w.r.t. require? Typing [foobar :as foobar] all over the place is getting just a little old. :-)
10:14	fogus	,(let [x (with-meta (lazy-seq (seq "foo")) {:bar 2})] [(class x) (meta x) (apply str x)]) ;; total hackery
10:14	clojurebot	[clojure.lang.LazySeq {:bar 2} "foo"]
10:15	seths	fogus: woah
10:15	seths	why wrap (seq) in a lazy-seq?
10:16	fogus	something to attach metadata to. But mostly just to be playful
10:18	seths	I noticed that deftype says it only works for interfaces, e.g. String is rejected, but Object works fine
10:18	seths	wonder why the special case? maybe since Object is the top of the Java food chain?
10:19	fogus	seths: For a string-like deftype, I would consider CharSequence
10:19	seths	hmm
10:19	chouser	that'll at least work with regex
10:19	chouser	iirc
10:26	seths	chouser: I think deftyping CharSequence would work with regex, but it would be painful
10:27	seths	have to expose all the methods that are invoked on CharSequence by the regex code
10:30	seths	anyways, just to wrap up the thought experiment with meta on a string
10:30	seths	this technically works but is really gross
10:30	seths	,(deftype MyStringType [a-str] CharSequence (toString [] a-str))
10:30	clojurebot	java.lang.Exception: Unable to resolve symbol: deftype in this context
10:30	seths	alas
10:31	seths	(str (with-meta (MyStringType "abc") {:foo 'bar}))
10:31	Chousuke	seths: I guess Object methods are overrideable because you're forced to derive from it in any case and not being able to override things would just be limiting
10:36	dabd	a very basic question: I thought the following would not work (let [a (ArrayList.)] (.add a "1") a) because the ArrayList would be immutable. Only Clojure data structures are immutable? If you create a Java data structure it is mutable? thx
10:37	Chousuke	dabd: the reference "a" is immutable, not the data structure itself
10:37	Chousuke	dabd: Clojure can't make Java's mutable things suddenly immutable :)
10:38	dabd	but if a was a ref to a Clojure map the map itself would be immutable (and also the ref)?
10:39	Chousuke	yes.
10:39	dabd	thx
10:44	angerman	I've created a pretty stupid ascii-progress chart i though I'd share: http://ideone.com/LU8RUJCD
10:47	dabd	(second [1 2])
10:48	dabd	,(second [1 2])
10:48	clojurebot	2
10:51	seths	cemerick: what's the latest on the string interpolation code?
10:51	cemerick	seths: sitting right over here :-) I suppose I should open a ticket for adding it, but I haven't heard much in the way of demand.
10:52	seths	I'm getting a little tired of (str x y z)
10:52	seths	wouldn't mind using it, not sure if there is any licensing on it yet?
10:53	tolstoy	seths: You mean something like Groovy's "some ${nice} interpolation?"
10:53	seths	tolstoy: exactly
10:53	seths	http://muckandbrass.com/web/display/~cemerick/2009/12/04/String+Interpolation+in+Clojure
10:54	cemerick	seths: feel free to use it. Wouldn't have posted it otherwise.
10:54	seths	great, thanks
10:54	joegg	Is there a single function that will build an infinite sequence from a single item, or should I just "(cycle (list 4))"? Basically, I'm looking for "constantly" except for sequences.
10:55	angerman	joegg: repeatedly
10:56	Chousuke	repeatedly is for functions
10:56	Chousuke	repeat is for items
10:56	tolstoy	seths: I kinda with that was in contrib. ;)
10:57	joegg	I guess you can clean it up a bit with (cycle [4]) instead of calling list.
10:57	Chousuke	,(take 5 (repeat 4))
10:57	clojurebot	(4 4 4 4 4)
10:58	joegg	Chousuke: That looks perfect.
10:58	Chousuke	it's optional :)
10:58	angerman	has it always been optional?
10:58	Chousuke	I don't think so.
10:58	angerman	hmm. so maybe my memory is just too old :)
10:59	Chousuke	there were two functions at some point
10:59	Chousuke	but then someone realised that repeat is enough :P
10:59	joegg	Okay, so: (constantly 4) will build a function that always returns 4, (repeat 4) builds an infinite sequence of 4, and (repeatedly somefn) will build a lazysequence based on the results of calling some function. Let's not even get into iterate. :)
11:00	joegg	And if I said something wrong there, please do correct me.
11:00	Chousuke	you're correct.
11:01	seths	tolstoy: cemerick is the author
11:01	Chousuke	iterate is not that difficult either. it just keeps calling the function on its return value
11:01	seths	I agree with you, would be nice to have around
11:01	joegg	Amazing. The only thing that worries me about clojure so far is that I'm bet I'm doing a lot of stuff like (cycle [4]) because I haven't yet internalized (for instance, (repeat 4).
11:02	cemerick	I guess that makes four 'seconds' on the notion of adding it to contrib. I suppose I'll have to open that ticket now. :-)
11:02	Chousuke	,(take 5 (iterate / 9))
11:02	clojurebot	(9 1/9 9 1/9 9)
11:02	Chousuke	:P
11:03	tolstoy	cemerick: Do you think there's room in it for adding formatter type things? Like ~0,2{num} for zero padding, or some such thing? Or would that be too much.
11:03	tolstoy	cemerick: I'm thinking that if you need more than simple interpolation, format works, but, I don't know, would be kinda cool for that once in a long while use case.
11:04	cemerick	tolstoy: yeah, there's lots of room for stuff like that. I haven't thought about it at all, though.
11:04	Chousuke	tolstoy: for that you probably want to take a look at cl-format in clojure.contrib
11:04	seths	cemerick: whatever you do, don't make it as painful as formatting std::cout is in c++
11:04	cemerick	I suppose I would like to reuse what java's Format provides.
11:04	tolstoy	cemerick: The danger is it becomes yet another embedded DSL. (like cl-format.... )
11:05	cemerick	yeah, I definitely would stay away from anything approaching CL's FORMAT.
11:05	cemerick	java.text.Format is just fine. Beyond that, go write a function, please.
11:05	tolstoy	Yes, String.format works for me.
11:06	tolstoy	But, I'd find it useful for logging. (log/info (<< "some ~{value} and another ~{thing}"))
11:06	tolstoy	But then I'm a "printf" debugger type. ;)
11:06	seths	tolstoy: there's a FaceBook fan page for that
11:06	seths	printf debugging
11:06	cemerick	I use << for logging all the time :-)
11:08	tolstoy	seths: debuggering? I'm not even going to try and picture that.
11:09	seths	lol
11:09	cemerick	oh, yeah, -?>> would be helpful
11:09	tolstoy	cemerick: maybe (log/info<< "the ~{a}'s have it")
11:09	seths	you could have special macros for logging
11:10	seths	like this for really bad errors (>_< "inconceivable!")
11:10	tolstoy	the smilification of logging, eh?
11:10	tolstoy	(; "it worked!")
11:11	seths	tolstoy: I see what you did there
11:11	tolstoy	(-( "error!"))
11:17	wooby	seths: LOL
11:17	wooby	(8-o "oh no!")
11:20	chouser	,'(T_T "Oh dear")
11:20	clojurebot	(T_T "Oh dear")
11:20	chouser	,'(x_x "failed completely")
11:20	clojurebot	(x_x "failed completely")
11:20	somnium`	http://www.lrde.epita.fr/~didier/software/smilisp.php << maybe there's something to this
11:21	the-kenny	Implementing smilisp is a bit hard because it isn't possible to define your own reader-macros in cloure code
11:21	tolstoy	And now we know why.
11:26	tolstoy	Can you use deftype/reify to, say, create a custom exception class in clojure? Dynamically?
11:27	Chousuke	hmm.
11:27	Chousuke	aren't they limited to interfaces?
11:27	tolstoy	That's what I was thinking (from what I read).
11:27	AWizzArd	Well, then there is still (proxy ...)
11:28	tolstoy	But that's not named, is it? You can't (catch CustomException ...), right?
11:28	stuartsierra	proxy won't create a named class that you can use in a try/catch
11:28	chouser	but you can't really rely on the name of the class ... right, whatever everyone is saying.
11:29	stuartsierra	If you want named classes, you must compile ahead-of-time.
11:30	tolstoy	I sometimes have a use case (web requests which in turn call other remote services), where I'd like to create an exception that has several attributes. I can throw it, and at the top I can just catch the exception, formulate an error response, and return.
11:30	chouser	defprotocol now creates named interfaces without AOT
11:30	chouser	tolstoy: look at clojure.contrib.condition
11:31	tolstoy	chouser: Ah, hm. I bet that's exactly what I need.
11:34	LauJensen	Is there something nice in contrib for downloading binary files?
11:34	tolstoy	Downloading from the web? http-agent works.
11:34	the-kenny	clojure-http-client should support this
11:35	LauJensen	k thx
11:36	angerman	Does anyone know how to figure out the iowait statistics on os x?
11:39	CalJunior	,(defstruct foo :bar)
11:39	clojurebot	DENIED
11:39	CalJunior	(defstruct foo :bar)
11:39	CalJunior	(def map1 (struct foo nil)
11:40	CalJunior	(assoc map1 :bar 1)
11:40	CalJunior	returns {:bar 1}
11:40	CalJunior	however if I call map1
11:40	CalJunior	it returns {:bar nil}
11:41	the-kenny	CalJunior: Clojure is a functional language with immutable data structures
11:41	CalJunior	Yes I know it's immutability.
11:41	fliebel	The assoc did not actually change anything...
11:41	fliebel	It only returned the changed struct
11:41	CalJunior	How do I get it to return {:bar 1}
11:41	CalJunior	?
11:42	ohpauleez	use an atom or a ref
11:42	the-kenny	CalJunior: try a ref or atom
11:42	fliebel	Why would you need that?
11:42	ohpauleez	fliebel's answer is the one to go with
11:42	ohpauleez	you really should ONLY do that if you have to
11:42	CalJunior	I only need to do it once at program start-up.
11:43	chouser	then why not (def map1 (struct foo 1)) ?
11:43	ohpauleez	maybe you just need to define one (def ...) that you need.
11:43	the-kenny	alter-var-root is propably what you want.. or (def) it with the right value
11:43	CalJunior	I need to map 'identities' to their place in a vector.
11:44	CalJunior	rather their index in vector.
11:45	the-kenny	,(hash-map (zipmap [:foo :bar :baz] (iterate inc 0))
11:45	clojurebot	EOF while reading
11:45	the-kenny	,(hash-map (zipmap [:foo :bar :baz] (iterate inc 0)))
11:45	clojurebot	java.lang.IllegalArgumentException: No value supplied for key: {:baz 2, :bar 1, :foo 0}
11:46	the-kenny	(zipmap [:foo :bar :baz] (iterate inc 0))
11:46	the-kenny	,(zipmap [:foo :bar :baz] (iterate inc 0))
11:46	clojurebot	{:baz 2, :bar 1, :foo 0}
11:48	the-kenny	uhh switch the arguments of zipmap
11:49	CalJunior	thanks the-kenny, but I'll try the atom idea first.
11:49	the-kenny	CalJunior: An atom slow compared to a simple "def"
11:50	the-kenny	too much overhead
11:50	CalJunior	speed is not a issue in this case
11:50	the-kenny	It also isn't the "Clojure Way" ;)
11:50	CalJunior	I thought atoms were quite zippy though.
11:51	chouser	using an atom except to coordinate multiple threads is best avoided.
11:51	hiredman	the-kenny: what would you know about it?
11:51	hiredman	alter-var-root is certainly not to be recommended
11:52	the-kenny	hiredman: I think that isn't a good problem for an atom. It looks like he doesn't really need mutable state here, as he only wants to do something while initializing the program
11:52	CalJunior	I timed the atom on a vector at 0.025 ms.
11:52	chouser	CalJunior: if you could more completely describe your input and desired output, we can probably give better advice.
11:53	the-kenny	hiredman: I'm absolutely not the haskell type (wtf, please, no state anywhere), but I think it should be avoided where it doesn't needs to be
11:54	CalJunior	chouser: I def a maps of values for a number of symbols.
11:54	CalJunior	most of these values a fixed and don't change ever.
11:55	chouser	it seems unlikely to me that any reference type needs to be updated.
11:55	CalJunior	however, one of them is set at the start-up of the program (daily).
11:55	chouser	CalJunior: "maps of values" still doesn't tell me much. Perhaps an example?
11:55	the-kenny	CalJunior: So you want to update a value later in the program?
11:55	CalJunior	yes.
11:55	the-kenny	Oh sorry
11:56	the-kenny	I misunderstand you.. an atom is the best way for this, of course.
11:56	the-kenny	Maybe a ref, if there needs to be some coordination etc. while setting from different threads
11:56	hiredman	CalJunior: is there a reason you can't just do (def map’ {:a 1 :b 2 :c (init-stuff-here)})
11:58	CalJunior	I think the atom is the obvious solution. So I'll let it rest.
11:59	CalJunior	chouser: love the book. as you can tell: I need it.
11:59	jcromartie	Would it make sense to use an agent with a nil value to handle saving data to disk?
11:59	jcromartie	I
11:59	DeusExPikachu	what is a fixnum and what is its purpose?
12:00	jcromartie	Or should the agent represent the data being saved?
12:00	Chousuke	jcromartie: I think it's okay to have a "serializing agent"
12:00	chouser	jcromartie: nil is probably fine. I've sometimes put the filehandle in there, but you have to be careful to always return it from your action functions
12:00	Chousuke	so that you can just do (send someagent write-to-disk whatever)
12:01	chouser	CalJunior: glad you like it.
12:01	chouser	CalJunior: thanks from fogus as well. :-)
12:02	chouser	DeusExPikachu: I think that usually refers to an efficient way to store numbers that know their own type, that's not supported by the JVM yet.
12:02	CalJunior	fogus: love your book too :-)
12:03	hiredman	if have the agent hold the data to be saved you can use a watch to write
12:03	jcromartie	hiredman: that's a good idea
12:03	Chousuke	hiredman: hmm, what if the data changes while the watcher is writing it?
12:03	jcromartie	so I send things like conj or assoc or dissoc
12:03	jcromartie	but the writes have to be in order
12:04	hiredman	,(doc add-watch)
12:04	clojurebot	"([reference key fn]); Experimental. Adds a watch function to an agent/atom/var/ref reference. The watch fn must be a fn of 4 args: a key, the reference, its old-state, its new-state. Whenever the reference's state might have been changed, any registered watches will have their functions called. The watch fn will be called synchronously, on the agent's thread if an agent, before any pending sends if agent or ref. Note tha
12:04	chouser	"The watch fn will be called synchronously"
12:04	jcromartie	ok
12:04	jcromartie	great!
12:05	jcromartie	now... is this so "experimental" that I shouldn't use it for production code?
12:05	jcromartie	otherwise I can just use a serializing agent
12:05	jcromartie	and call it a day
12:05	jcromartie	send-off would do the trick
12:05	chouser	jcromartie: that usually has more to do with the chances of the api changing than the code breaking.
12:06	jcromartie	I see
12:07	DeusExPikachu	chouser, thanks, now the jvm talk makes sense
12:09	chouser	DeusExPikachu: sure. the details are interesting too, if you're into that kind of thing.
12:10	DeusExPikachu	chouser, I'm watching "Fast Bytecodes for Funny Languages" and Cliff is talking about why clojure is close speed to java, and what it needs to do to close the gap
12:10	chouser	ah, yep. fixnums would be great for clojure.
12:10	chouser	meanwhile, rhickey's doing what he can to work around the problem. :-)
12:19	DeusExPikachu	chouser, I dont' know if you've watched the talk, but do you know if Escape Analysis is typically performed at the JIT level, or the clojure compiler level?
12:20	chouser	The Clojure compiler doesn't do much optimization at all. Post-1.1 it's now doing some fine-grained locals clearing, but any escape analysis is being done by the JVM.
12:21	chouser	Hm, I guess Clojure's also now doing some clever things with method caching at call sites, and some explicit (macro-style) inlining.
12:22	hiredman	that would be for deftype and protocols?
12:23	chouser	hiredman: yes, where (:foo bar) can be as fast as a direct field lookup, like a type-hinted (.foo bar)
12:23	chouser	I think that's the only place the call-site caching is done, but I may have forgotten something.
12:24	hiredman	do protocol fn call sites do some caching?
12:24	chouser	hm, perhaps that too. I haven't tried to read the implementation for any of that yet.
12:27	seths	cemerick: hey, email me if you are unhappy with http://bitbucket.org/seths/pokerepl/src/39b5efb4e905/src/com/muckandbrass/interpolate.clj
12:33	tayssir	Hi! I'm trying to search for the reasoning why add-classpath's deprecated... any pointers? (To get add-classpath's dynamicity, am I supposed to unzip the .jar into my classpath or something?)
12:37	hiredman	add-classpath was only ever supposed to be used in a very limited set of circumstances, since the visibility (scope) of classes loaded that way cannot be guaranteed
12:38	tmountain	is there a way to write this with the arrow operator? (get (get x "foo") "bar")
12:38	tmountain	or some better way to write it?
12:38	hiredman	it's deprecated generally because people were unable to keep themselves from using it only for experimental repl sessions
12:38	hiredman	(-> x (get "foo") (get "bar"))
12:39	tmountain	thanks hiredman
12:39	hiredman	the real solution appears to be a custom classloader as the system classloader durring developement
12:40	hiredman	but this has yet to be codified
12:40	hiredman	(honestly it's a fairly simple bit of code, so it should be)
12:40	Chousuke	isn't there a get-in as well?
12:41	hiredman	(doc get-in)
12:41	clojurebot	"([m ks]); returns the value in a nested associative structure, where ks is a sequence of keys"
12:41	hiredman	Yes
12:41	tmountain	ahh, that's what I was looking for
12:41	tmountain	I was browsing clojure categorized... I see it's under structs rather than maps on there
12:42	tayssir	hiredman: Ah, cool, thanks.
12:45	lypanov	gen-in is cute
12:46	Chousuke	update-in and assoc-in are also neat :)
12:46	Norrit	hi, I am looking for some kind of "flat" operation, is there something available?
12:46	Chousuke	Norrit: flatten? clojure.contrib.seq-utils
12:46	Norrit	ah .. thx :-)
12:47	Chousuke	contrib contains a lot of stuff
12:47	konr`	is it safe to assume that a randomly generated string does not occur in a file?
12:48	the-kenny	,(doc gen-in)
12:48	clojurebot	It's greek to me.
12:48	the-kenny	Oh, get-in?
12:48	Chousuke	konr`: depends how good your PRNG is :P
12:49	Chousuke	also on the length of the string :)
12:49	hiredman	konr`: no
12:49	hiredman	a file is random collection of strings
12:49	Chousuke	mmh
12:49	Chousuke	most often not random
12:50	Chousuke	but still, nothing would prevent anyone from looking up one of your randomly generated strings and putting it in a file.
12:50	lypanov	the-kenny: aye, sorry. fingers are tired :D
12:50	hiredman	Chousuke: unless you know the contents of the file, it is random
12:50	the-kenny	lypanov: I was just asking because I never heard of gen-in
12:51	lypanov	maybe i should invent it
12:51	Chousuke	konr`: What are you you trying to accomplish?
12:51	hiredman	but unless you have actually checked to see if a random string exists in a file, it is not safe to assume it isn't in the file
12:51	lypanov	man this parleys thing uses a ton of cpu.. wonder where the vids are
12:51	Chousuke	hiredman: the contents of the system files on my hard disk are definitely not random, though I don't know it :)
12:52	Chousuke	I guess the issue here is about probability
12:52	Chousuke	I mean, it's not safe to assume that a hash does not collide with anything in the future
12:53	Chousuke	by your logic.
12:53	konr`	Chousuke: I want to generate a Boundary string to a multipart POST request, and I'm a little confused. In Drakma's source code, the string is random, but here: http://www.ietf.org/rfc/rfc2388.txt it says that the string should not appear on the content
12:53	konr`	Chousuke: drakma, the CL equivalent
12:53	Chousuke	konr`: generate a UUID or something
12:53	Chousuke	konr`: those are designed not to collide with each other :P
12:54	Chousuke	or you could hash the content that you're separating
12:54	Chousuke	then use /hash/
12:54	Chousuke	or whatever
12:56	Chousuke	It's rather unlikely that any good hash function would generate output A from content that contains A :P
13:05	ohpauleez	konr`: you want to use HtmlUnit and interop + enlive
13:05	ohpauleez	that's what I've been doing
13:09	konr`	ohpauleez: "GUI-Less browser for Java programs" - hmmm, I didn't knew about this one
13:09	konr`	I'm going to try it out, thanks guys!
13:10	ohpauleez	totally welcome, I've been working on ripping parts of htmlunit out, and wrapping it a more functional way
13:11	hiredman	htmlunit is pretty nice
13:11	ohpauleez	agreed
13:12	the-kenny	http://kvardek-du.kerno.org/2010/01/how-common-lisp-programmer-views-users.html Clojure is Picard as a Borg :/
13:14	wilig	technomancy: did you have a chance to look at clojure/repl? I tried the simple approach but didn't get far.
13:15	vu3rdd	I am trying to write an insertion sort routine.
13:15	vu3rdd	as a first step, I created an insert routine, which takes an integer and a sorted sequence as parameters.
13:16	vu3rdd	it works except when the number to be inserted in greater than all the elements in the list.
13:16	vu3rdd	The code is here: can someone help find the problem?
13:16	vu3rdd	http://paste.lisp.org/+2099
13:17	cemerick	Good for a laugh, if folks haven't seen it yet: http://kvardek-du.kerno.org/2010/01/how-common-lisp-programmer-views-users.html
13:17	hiredman	vu3rdd: first (seq key) is most likely not what you want
13:18	hiredman	for the empty case
13:18	hiredman	(seq [key]) or (list key)
13:19	hiredman	infact
13:19	vu3rdd	ok
13:19	hiredman	that might be the actually problem, since it is the base case
13:19	hiredman	so do that and try again
13:20	vu3rdd	hiredman: thanks. yes indeed.
13:20	vu3rdd	I was struggling with it for a long time today! :-(
13:21	hiredman	seq is not like list or vector
13:21	hiredman	seq returns a seq on a collection, it doesn't create a collection
13:22	vu3rdd	ok.
13:22	vu3rdd	so, any collection can be converted to sequences and can be thought of as a logical representation of any collection? is that a fair statement?
13:25	tmountain	anyone know any existing libs for downloading binary data using something like InputStream and OutputStream?
13:26	Chousuke	vu3rdd: seqs are logical views to a collection, yes.
13:27	vu3rdd	Chousuke: thanks
13:28	Chousuke	vu3rdd: seqs are also persistent, ie. once you have realised (accessed) a part of a seq, that part is immutable. this means weird things can happen if you make a seq on a mutable array and then modify the array afterwards
13:30	vu3rdd	Chousuke: thanks. But aren't vectors, maps and lists also persistent? I guess by Arrays, you mean the Java Arrays?
13:30	Chousuke	yes
13:31	Chousuke	,(let [a (into-array [1 2 3 4 5]) s (seq a)] (println (first s) ".") (aset a 0 42) (println (first s) ".") (println (aget a 0) "."))))
13:31	clojurebot	1 . 42 . 42 .
13:31	Chousuke	hmm.
13:32	Chousuke	I guess not cached in that case :/
13:32	chouser	I think lazy seqs cache, not all seqs.
13:32	vu3rdd	ok
13:32	Chousuke	chouser: might be.
13:33	Chousuke	,(let [a (into-array [1 2 3 4 5]) s (doall (seq a))] (println (first s) ".") (aset a 0 42) (println (first s) ".") (println (aget a 0) "."))))
13:33	clojurebot	1 . 42 . 42 .
13:45	hiredman	…
13:46	jkdufair	Anyone played with Alice? I see it's Java. Might be fun to bolt clojure on top of it somehow.
13:46	LauJensen	Guys - I had a thought earlier. Previously when there's been a challenge like prime-finding, Lucas-Lehmann, Hamming numbers etc, I've joyfully used lazy-seqs to get the data I want. Now with chunked-seqs do I still dare? I imagine that with Mersenne Primes for instance the computations run for 8+ hours once you get beyond the 10.th number or so, so wont a seq representation effecually be impossible because the CPU will burn out trying to get the
13:47	chouser	LauJensen: you may need to be careful, yes. But many seqs are still not chunked.
13:47	LauJensen	many?
13:47	chouser	many
13:47	hiredman	anything using range is chunked
13:48	LauJensen	hehe
13:48	chouser	anything you build manually using lazy-seq and cons is not chunked
13:48	LauJensen	Aah ok
13:48	LauJensen	Thats good news
13:48	chouser	anything using iterate is not chunked.
13:48	LauJensen	Preferably it would just be made explicit somehow if you want chunks or lazy seeing they're 2 different things
13:49	chouser	any of the seq library functions that consumes a non-chunked seq, produces a non-chunked seq.
13:49	Chousuke	it is kind of explicit right now.
13:49	Chousuke	there's just no function to convert from a chunked seq to a non-chunked one
13:49	chouser	we could use a seq1 fn. Not sure why we don't have one yet.
13:49	LauJensen	You dont me literally seq1 ?
13:50	Chousuke	seq1 is not a bad name. :)
13:50	chouser	yes, a seq1 that accepts a collection (or chunked seq) and returns a guaranteed non-chunked seq
13:50	rhickey	http://paste.lisp.org/display/90536
13:50	Chousuke	I wonder if you can guarantee that for nested chunked seqs though? :/
13:50	rhickey	just a rough draft
13:51	chouser	iterate, for example, could potentially be faster producing a chunked seq, but if there were code written relying on it being non-chunked, that could be considered a breaking change. :-/
13:52	chouser	if we had an idiomatic seq1, then seq-returning things in generally could be considered potentially chunked, and code that needed non-chunked would explicitly use seq1
13:53	hiredman	bleh
13:54	chouser	considering how little complaints we've heard about chunked seqs, I would imagine use of seq1 would be pretty rare.
13:54	Chousuke	I think it would serve as documentation too
13:54	chouser	yes
13:55	hiredman	bleh
13:55	Chousuke	hiredman: do you have a better solution?
13:55	chouser	hiredman: do you have an alternative you'd like to propose? :-)
13:55	chouser	heh
13:55	Chousuke	or should we call seq1 "bleh"?
13:56	hiredman	I like it when map, filter, etc were lazy
13:56	hiredman	liked
13:56	chouser	you would prefer to not have chunked seqs at all?
13:56	technomancy	wilig: not yet unfortunately
13:57	hiredman	I have to run catch a bus, but I would prefere explicit chunking to explicit seq-1
13:57	Chousuke	the non-chunkedness will propagate though won't it?
13:57	technomancy	wilig: I ordered a nexus one and have been distracted by the android emulator. =)
13:59	Chousuke	so if you have (map ... (filter ... (map expensive-op (generate-chunked-seq)))) then you should be able to make the whole thing non-chunked by just wrapping the map operation in seq1
13:59	chouser	the inner map, yes
14:00	chouser	well
14:00	chouser	no
14:00	chouser	(seq1 (generate-chunked-seq))
14:00	chouser	,(first (map prn (range 10)))
14:00	clojurebot	0 1 2 3 4 5 6 7 8 9
14:01	Chousuke	hiredman: I think having seq1 as the non-default op makes sense, because otherwise you'd need a lot of ceremony just to get the performance benefits.
14:02	Chousuke	hiredman: and in the vast majority of cases it makes no difference whether a seq is chunked or not
14:02	Chousuke	except that the chunked seq is faster, of course
14:04	Chousuke	but I guess if chunked seqs ever turn out to have been a really bad idea, the whole mechanism can just be removed :/
14:08	hiredman	well, the bus drove away while I was running along side it yelling and pounding on the side of the bus trying to get the driver's attention
14:08	chouser	:-(
14:08	chouser	wait -- is that a metaphore for chunked seqs?
14:08	hiredman	could be
14:09	Chousuke	heh
14:09	Chousuke	you just need to make a convincing enough case against chunked seqs
14:10	hiredman	I like lazy seqs
14:10	Chousuke	yes, and chunked seqs are still lazy.
14:10	Chousuke	only less lazy than before.
14:10	wilig	technomancy: excellent. enjoy. I'm tempted to finally succumb to the smart phone itch. It's not the price of the phone that gets me, it's the recurring costs.
14:10	hiredman	yes, and less is less
14:10	Chousuke	and if (when) seq1 is introduced, you have an explicit way of getting back to the old semantics
14:11	Chousuke	so what is there not to like?
14:11	Chousuke	that you might need to wrap some seqs in seq1 sometimes? :/
14:13	hiredman	chunked sequences basically go back on http://groups.google.com/group/clojure/browse_thread/thread/88d9fdb5bcad36a , so nil punning is gone for nothing
14:14	lisppaste8	fogus pasted "seq1 -- for my version of clojure" at http://paste.lisp.org/display/93650
14:15	Chousuke	hiredman: except seq1 rectifies that too
14:16	LauJensen	I prefer the speed that the chunks come with, so thats a good default, but it does change the way you can think about seqs a little bit
14:16	Chousuke	hiredman: and lazy sequences are still there. chunked sequences are just another, less lazy type of seq :P
14:16	rhickey	hiredman: no, they don't, as a chunked seq does nothing until something is asked for. When asked, it does more. And given some seq1-style source for seqs, it will be exactly as before
14:17	rhickey	hiredman: but you haven't proposed an alternative. Explicit chunks, linke chunk-map, chunk-filter etc? 2 versions of everything?
14:18	rhickey	once a seq is single, existing fns will process one-at-a-time
14:19	rhickey	or a (chunked-seq x) to start the chunked chain?
14:19	technomancy	wilig: yeah, with Google voice being able to fall back to wifi for calls means 95% of my voice usage will be free
14:20	rhickey	just saying bleh doesn't move the dialogue forward, and people want the perf benefits. As is now obvious, people aren't suffering much from the theoretical problem
14:21	slava	it just occurred to me that inserting usage of transients is something the compiler could do, at least in simple cases
14:22	Chousuke	slava: possibly, but that would be complicated
14:22	slava	also, what happened to 'persistent data structures are fast enough for everything' :-)
14:22	Chousuke	slava: even for simple cases :)
14:22	stuartsierra	slava: the core functions, like "into", already do.
14:22	Chousuke	slava: was that ever claimed?
14:23	technomancy	"everything" is a tricky term. =)
14:24	Chousuke	Clojure is developed kind of incrementally.
14:25	Chousuke	transients are just one new tool in the box :P
14:25	technomancy	slava: nobody wants to work on the compiler right now since it's going away with self-hosting around the corner. but it's certainly an interesting idea.
14:25	angerman	technomancy: is that look and feel issue going into lein soon?
14:25	technomancy	angerman: are you getting it on the latest version? or is it just a problem with the release?
14:26	angerman	technomancy: using the latest release, lein pulles on self-install (from yesterday)
14:26	technomancy	angerman: oh, I thought that had been fixed
14:26	technomancy	angerman: unfortunately it only manifests on OS X, so all I can do is accept patches
14:27	slava	transients are an interesting optimization. its not safe if you have multi-shot continuations
14:27	angerman	yes, I had it hand compiled for me. but then lein from the checkout was screweing with the classpath too much, so i cleared all of lein I had and pulled the version from the net.
14:28	Chousuke	I somehow doubt that Clojure will ever gain features that break transients (might deprecate some usage patterns) but amusingly enough it should be easy to remove them, too.
14:29	Chousuke	just make persistent! and transient no-ops and maps the ! ops to regular assoc etc. :P
14:32	angerman	technomancy: lein swank still crashes. Let's see if i find the patch that fixed it for me the last time
14:32	patrkris	hey... i'm looking for a quote that says something along the lines of "object-oriented design patterns were made to solve the deficiencies of OOP"
14:32	patrkris	for some reason, I think it might have been rhickey who said it
14:33	patrkris	or maybe he was quoting someone else
14:40	angerman	technomancy: I'm sure it was this patch: http://github.com/swannodette/leiningen/commit/9d79d631a9faa870a9347992f50a4312170fdf97
14:41	wooby	angerman: is the OS X bug mentioned in the commit msg the OS X java runtime stuff not being on classpath?
14:42	angerman	wooby: that might be the case. It only happens with lein swank though
14:42	technomancy	angerman: right, that slows every execution down for everyone
14:42	technomancy	everyone else shouldn't have to be affected by a workaround for an OS X bug
14:42	angerman	technomancy: hmm ok, didn't know it caused slow down
14:45	Raynes	http://www.reddit.com/r/programming/comments/artiq/clojure_11_12_and_beyond_what_is_clojure_in/c0j3c8e :>
14:46	wooby	maybe lein swank could just sniff if OS X and include JavaRuntime.jar in -extra-classpath if necessary
14:46	wooby	i'll take a stab at it
14:51	angerman	wooby: (defn osx? [] (= (System/getProperty "os.name") "Mac OS X"))
14:51	angerman	wooby: if that helps :D
14:51	wooby	angerman: there 'tis :)
14:52	Raynes	,(System/getProperty "os.name")
14:52	clojurebot	java.security.AccessControlException: access denied (java.util.PropertyPermission os.name read)
14:52	Raynes	:<
14:52	jasapp_	I was about to try the samething
15:07	ts00000	so, is technomancy's clojure-http-client the canonical way to do REST-type stuff these days?
15:08	ts00000	e.g. http post.
15:10	the-kenny	Okay.. how do I merge two (or more) lists: (f [1 3] [2 4]) -> [1 2 3 4]
15:10	somnium`	concat
15:10	chouser	those are vectors
15:10	chouser	you want to keep them in order?
15:10	chouser	sorted order, I mean?
15:11	the-kenny	chouser: Yes
15:11	chouser	and you promise the input seqs are already in order?
15:12	the-kenny	I get one from a [& foo
15:12	the-kenny	] function argument
15:12	chouser	if they're not already sorted, I don't think you can do better than (sort (concat c1 c2))
15:13	wooby	interleave would work, at least in that case
15:14	the-kenny	I think I'll stick to (seq (zipmap ...)), the order of the interleaved pairs isn't very important, just that they're pairs
15:15	chouser	I don't see how that's at all similar, but if you've got something that works, then great.
15:17	the-kenny	chouser: (fun ['foo 'bar] [:foo :bar]) should return either [foo :foo bar :bar] or [bar :bar foo :foo
15:17	the-kenny	+]
15:23	ohpauleez	the-kenny: that's different from the orginal goal, in that case, zipping is what you want to do
15:27	chouser	,(interleave ['foo 'bar] [:foo :bar]) ; ?
15:27	clojurebot	(foo :foo bar :bar)
15:28	chouser	zipmap returns a map collection, not a vector or sequence.
15:28	ohpauleez	right
15:29	ohpauleez	and I suppose if you really wanted a vector, just toss a into [] in front of the interleave
15:29	chouser	yes, or 'vec' :-)
15:29	ohpauleez	that would work too :)
15:38	CalJunior	I have: (def foo { :bar ( atom { } ) } )
15:38	CalJunior	how do I swap the atom?
15:39	CalJunior	for example to 1
15:39	chouser	(update-in foo [:bar] swap! assoc :a 1)
15:39	chouser	hm.
15:39	chouser	no
15:40	CalJunior	returns {:a 1}
15:40	CalJunior	I would like it to return 1
15:40	chouser	(swap! (:bar foo) assoc :a 1)
15:44	CalJunior	chouser: thanks
15:45	CalJunior	I guess I have to change the atom from a map to a vector to just get 1
15:45	chouser	an atom can hold a single number instead of a collection if you'd like
15:46	CalJunior	that's what I would like
15:46	chouser	,(let [a (atom nil)] (reset! a 1) a)
15:46	clojurebot	#<Atom@192caa9: 1>
15:48	chouser	I continue to doubt that an atom is the best solution for you
15:49	CalJunior	I know what you mean.
15:49	CalJunior	(atom nil) was the key for me here.
15:49	CalJunior	works
15:50	CalJunior	I'll try to find a different solution later.
15:53	wilig	technomancy: New version of swank-clojure pushed to github. This one proxies LineNumberingPushbackReader. It's a small step on the path toward clojure.main/repl
16:07	ts00000	there is no deliberate slowdown
16:08	ts00000	wrong chan
16:13	ts00000	doesn't swank-clojure-project autoload everything in ~/project/lib?
16:13	ts00000	in terms of classpath?
16:23	stuartsierra	Hey Maven fans (& not). I'm working on a Maven-based build for contrib.
16:25	lpetit	cool
16:26	stuartsierra	It's SO much simpler than the Ant build.
16:27	chouser	why's that?
16:28	stuartsierra	No test script needed, far fewer exclusions needed when compiling, no need to manually define how to find/compile .clj sources, ...
16:30	stuartsierra	Basically, all the complexity of the Ant script is moved to the Maven plugin.
16:30	chouser	ah
16:31	stuartsierra	And the plugin is published in the central repository, so we don't need to distribute it.
16:34	stuartsierra	Check it out: http://github.com/richhickey/clojure-contrib/tree/maven
16:37	stuartsierra	No need to specify where to find clojure.jar on the command line...
16:38	zakwilson	I just set up a new machine with a new install of swank-clojure and an old .emacs file. It's saying java.lang.NoClassDefFoundError: clojure/main
16:39	zakwilson	and swank-clojure-jar-path is set to a real working clojure.jar
16:39	lpetit	stuart, are you a new convert, or did you know/use maven for a long time ?
16:40	stuartsierra	lpetit: I've been advocating Maven for Clojure projects for a while now. I wrote several blog articles on the subject.
16:40	lpetit	ok, was just wondering :-)
16:41	stuartsierra	http://stuartsierra.com/tag/maven
16:41	lpetit	I'm currently starting a project with GWT. Was wondering whether I would use ant or maven for it, just today :-). But I would really have loved being able to work with clojure full stack with GWT :-(
16:42	chouser	I think Clojure is less compatible with GWT than it is with C++ libs
16:43	jcromartie	ouch
16:43	stuartsierra	GWT is a Java source compiler, not much to be done about that.
16:43	chouser	and GWT can't compile Clojure's java sources
16:43	chouser	or couldn't last I tried, anyway.
16:43	lpetit	guessed so :'(
16:44	chouser	the only hope would be after cinc to write a java-source backend specifically designed to stay compatible with GWT requirements.
16:46	lpetit	yes. Some guys also reused the java->js compilation mechanism to extend it to their own classes. Depends on the size of the stuff to do, as always (e.g. a guy created QWT, qooxdoo widget toolkit, based on the google's compiler, AFAIK)
16:51	ts00000	this is really bizarre
16:51	ts00000	swank-clojure-project isn't adding my ~/project/lib to classpath
17:06	heow	Just fired up the latest NetBeans and Enclojure, getting an NPE when creating a new project. is this a known problem?
17:11	heow	Anybody use the [theoricicly user-friendly] NetBeans?
17:13	lpetit	I've just read interesting things about zippers, and will tend to become a zipper fan very quickly. So ... before I over abuse the tool, what are the limitations of zippers I don't see right now ? Where should they be avoided, for instance ? If not theoretically, at least given the current implementation in clojure.zip ...
17:14	technomancy	ts00000: it should add all the jars in $PROJECT_ROOT/lib to the classpath
17:14	dabd	how the see the value of classpath from a project REPL in netbeans 6.8?
17:14	chouser	zippers are pretty amazing, but they're not amazingly fast, and the way I used them in zip-filter turned out to be unexpectedly limiting.
17:14	stuartsierra	Simplifying contrib build with Maven: http://groups.google.com/group/clojure-dev/browse_thread/thread/cd807a1e5d7ce77d
17:17	lpetit	I thing I'll use them with the parsetree of the code of paredit.clj, to go to the node corresponding to the caret, and then from it find the parent, the previous siblings, etc. A limited number of operations, mostly navigational
17:17	heow	dabd: Oh hey, yeah the REPL's sig changed in 1.1. Bet that's it, thanks!
17:19	lpetit	But I'm currently "reinventing the wheel" in the parser code. I browse the code from first to last char, creating events as I go: entering a () , entering spaces, quitting spaces, entering an atom, quitting an atom, etc. So I keep a stack of the parents, and when I quit node, I "close" the node with the info I've gathered on it so far, peek the parent from the stack, update it with the...
17:19	lpetit	..."closed" node by adding it as last child, and replace the parent on the stack.
17:20	dabd	heow: I'm still running clojure 1.0 with netbeans (because I cannot get 1.1 to work with the latest enclojure). I'm puzzled by this. It thought starting a proj REPL would take care of setting the classpath correctly
17:20	lpetit	So, basically, I guess I've reinvented a specialized version of a zipper with a limited subset of operations on it, and without the need to maintain an "after focus point context", just a "before focus point" context
17:21	lpetit	But I'm pretty sure my solution is efficient since I can see no superfluous (no non-essential) task in it.
17:22	jasapp_	say I've got my.ns.foo, and my.ns.bar, which have similar functions, but are different internally
17:22	lpetit	But the question remains : will I also use zippers for the construction phase, or will I suffer a penalty I can't afford ?
17:22	jasapp_	and I want my other code to be able to switch back and forth between them, interface-like
17:22	jasapp_	what's the best way to do that?
17:22	ts00000	technomancy: if it's not, where should I start to debug?
17:22	lpetit	chouser: what do you thing about it ? (and please don't tell me it will be in chapter xX of joc :-) )
17:23	chouser	lpetit: hehe
17:23	ts00000	technomancy: if it's in ~/.swank-clojure it's fine, if it's in the lib directory it doesn't work
17:23	chouser	lpetit: I'm afraid I don't grasp your whole context sufficiently to say. You're talking about parsing a stream of bytes into some kind of tree?
17:23	ts00000	chouser: is there a way I can play with require without redeclaring my entire ns? I tried (require 'clojure.contrib.zip-filter) which works, but I can't seem to access any of the xml-> things
17:24	technomancy	ts00000: check the elisp value of swank-clojure-classpath with C-h v
17:24	ts00000	technomancy: I did that, it's not there
17:24	ts00000	technomancy: but it's definitely in my lib directory
17:25	stuartsierra	ts00000: require does not 'refer' symbols into the current namespace
17:25	ts00000	stuartsierra: but shouldn't I be able to do (clojure.contrib.zip-filter/func ...) ?
17:25	technomancy	ts00000: I've never heard of that failing on a project that's laid out according to the directions in the swank-clojure-readme
17:25	stuartsierra	ts000000: yes, you should
17:25	stuartsierra	In that case the problem is somewhere else.
17:26	ts00000	technomancy: http://pastie.org/787307
17:26	lpetit	chouser: I'm the 100tiest guy to rewrite a clojure source code parser manually. For my purpose I'm just interested in a parsetree of the clojure code, and for the moment not interested in anything else than structural nodes (parens, square brackets, round brackets, strings, regexps, comments) and just 3 kinds of atoms: literal chars, spaces and the rest
17:26	ts00000	technomancy: did I miss something?
17:27	lpetit	chouser: this should give you ideas of the size and depth of my tree. clojure/core.clj is used for tests, since I see it representing an upper limit :-)
17:27	technomancy	ts00000: when you do M-x swank-clojure-project, you input the directory containing lib/ ?
17:27	ts00000	technomancy: yessir
17:27	chouser	lpetit: I think zippers will only be useful to you if you produce a tree of some kind from the parsing, and then keep it in memory while using the zipper api to navigate it.
17:28	lpetit	chouser: so too heavy for massive edit operations ?
17:28	chouser	lpetit: if I understood your description correctly, you're currently not holding the whole thing in memory, just keeping a stack representing your nested context?
17:28	ts00000	technomancy: SLIME 20091016, emacs 23.1.91.1, osx
17:29	technomancy	ts00000: is that slime from elpa?
17:29	ts00000	technomancy: yes
17:29	chouser	lpetit: you'll have to determine that yourself, I'm just saying it has to be in memory, at least ... well ... hm.
17:30	lpetit	chouser: well, the core function is just interested in navigating the code beginning-to-end, keeping a stack of the parents of the current node, and call hof arguments that do whatever they want in the process (they are called for each character, and given the current stack, offset, line, column context)
17:30	chouser	lpetit: this is for paredit-like functionality?
17:30	lpetit	i'm currently implementing a version of the hof arg which will write the complete parsetree
17:31	lpetit	for other simpler cases, i'll implement less heavy hof args to just peek what I want on the fly
17:31	lpetit	chouser: did I forget to mention that i also reinvented SAX in the process ? :-)
17:31	chouser	hm...
17:31	ts00000	technomancy: also, I seem to have to declare the (require 'clojure.http.resourcefully :as resourcefully) inside a namespace - is that normal, I assume so
17:31	technomancy	ts00000: what do you get evaling this elisp? http://p.hagelb.org/classpath.html
17:31	lpetit	chouser: yes, it's my "paredit.clj" project
17:31	chouser	lpetit: you didn't use that word, but I guessed so.
17:31	chouser	lpetit: SAX, I mean.
17:32	technomancy	ts00000: that's fine for resourcefully, though it's better to keep it inside the ns form with (:require [clojure.http.resourcefully :as resourcefully])
17:32	chouser	lpetit: so do you know where the cursor is and what kind of operation the user's trying to do?
17:33	ts00000	technomancy: i'm saying I can't seem to declare it outside the ns, e.g. in a repl. also, evaling your lisp gave the right classpath results, but for some reason it's like your function doesn't get called when I do swank-clojure-project
17:33	ts00000	if I just call it directly that doesn't show up in the classpath var
17:33	lpetit	chouser: sure. it's easy to go to the right node from the offset of the cursor by elimination, given that I currently store the offset and length of each node. I have no doubt concerning the navigational part : I'll user zippers. It's the creational part where I was pondering the overhead of using zippers.
17:34	technomancy	ts00000: you could (setq swank-clojure-classpath [the code I pasted]) for now and use M-x slime instead of swank-clojure-project
17:34	chouser	lpetit: oh, once you've built a whole tree, making a zipper of it is very fast
17:34	ts00000	technomancy: yeah, I can edit the classpath manually so i'm not too concerned, just surprised it didn't work is all
17:34	jcromartie	a little bit off-topic, but what color-theme are you using in Emacs?
17:34	technomancy	but I can't reproduce your problem, so not much else I can do
17:35	technomancy	jcromartie: that would be zenburn
17:35	technomancy	it's not a built-in theme
17:35	ts00000	technomancy: is there a way to trace what's being done when I swank-clojure-project?
17:35	technomancy	ts00000: you could add calls to message in the function
17:36	technomancy	the output goes to the Messages buffer
17:36	technomancy	given the correct project root, the classpath seems to be calculated correctly
17:36	lpetit	chouser: FYI, I'm writing paredit.clj in an IDE agnostic way, purely clojure of course (and as idiomatic as I'm capable of, given that I've just sacrificed modularity over premature optimization in the main loop), and not just a port of paredit, but will be tailored for clojure (will know literal sets so that when selecting them you also have the leading sharp in the selection, etc.)
17:36	jcromartie	I have tried light-on-dark themes and it doesn't work well with OS X's LCD font smoothing. Light-on-dark ends up making the text heavier.
17:38	ts00000	technomancy: using trace-function, the path seems to be set correctly, but even when I fully qualify the path, the classpath only shows what's in ~/.swank-clojure
17:38	chouser	lpetit: I wonder if it would be faster and more robust in the face of incomplete code files to start at the cursor and word backwards/forwards just as much as needed to complete the user's operation
17:38	ts00000	technomancy: in fact, if ~/.swank-clojure is empty, nothing on the classpath at all.
17:38	ts00000	weird.
17:38	technomancy	ts00000: oh, I realized it's done a little differently now. the swank-clojure-classpath elisp var is only modified inside a let binding
17:39	technomancy	so once the repl session is launched, it goes back to its root binding
17:39	technomancy	so try messaging it right before the call to (slime) at the end
17:40	joegg	Is there any plan to make the various clojure launcher scripts a part of clojure generally, or is it up to individuals and package maintainers to keep rewriting them? (I ask because I just found what I think is a bug in the macports clj script.)
17:40	technomancy	joegg: sooner the better, but I don't know of any concrete efforts to do so unfortunately =\
17:41	ts00000	technomancy: what, just (message "%s" swank-clojure-classpath) or something?
17:41	lpetit	chouser: I've considered this possibility, and rejected it, for two reasons : I wanted to please myself by writing a parser manually, which I had never made before, and I hope that Christophe will quickly release a workable version of parsley, which, with its incremental parsing feature, will be unbeatable
17:42	technomancy	sure
17:42	chouser	lpetit: ok. so building a tree that can be used by a zipper should cost essentially no more than building a tree.
17:42	chouser	lpetit: or are you asking about using the zipper api to build the tree itself?
17:43	lpetit	chouser: yes, asking about the added overhead of using the zipper api for building the tree (edit and al) too
17:46	chouser	lpetit: I think building using insert-left, insert-child, replace, etc. will only be a small constant factor slower than building a plain persistent tree
17:47	ts00000	technomancy: I have something interesting to report. inside your function, everything is declared normally
17:47	ts00000	technomancy: it's almost as if the classpath gets reset after slime
17:47	chouser	lpetit: so, not an unreasonable thing to try, I think.
17:47	ts00000	technomancy: path is correctly specified, and your code is correctly expanded
17:47	lpetit	chouser: ok, so worth considering a zipper as my state, will avoid me some boiler plate code. Will try this , thanks!
17:48	chouser	lpetit: sure, good luck.
17:48	chouser	hm. (seq-zip (read foo))
17:49	technomancy	ts00000: yes, since the classpath is set inside a let form, the changes are localized to that function call
17:49	technomancy	but since elisp doesn't have lexical scope but dynamic only, the call to slime sees the new value.
17:50	joegg	technomancy: What would a standardized clj script require? Pretty much just writing one and asking someone to pull from a branch? Or, if you know, what has prevented this from already being done? This seems like something I could roll up my sleeves and do.
17:50	joegg	Unless there's massive problems that I'm just too ignorant to see. :)
17:50	ts00000	technomancy: ok, I see what you're saying, so how do I fix it so the command is useful again :-)
17:51	ts00000	technomancy: let me rephrase that
17:51	technomancy	joegg: I think rich just hasn't made it a priority because he assumes everyone's going to get set up with Emacs or Netbeans or whatever.
17:51	ts00000	technomancy: I know how to fix it on my side, but how can I fix it so that rather than setting this manually on a per-project basis, it's dynamically set within swank-clojure-project and passed correctly
17:52	technomancy	ts00000: well because of the way dynamic binding works, it does get passed correctly from swank-clojure-project's let binding into the call to slime
17:53	ts00000	oh, I see what you're saying
17:53	ts00000	you're saying slime does see the right classpath
17:53	ts00000	but it's cleared after i've entered slime
17:53	ts00000	so that when I look at the variable it's wrong
17:53	technomancy	yes, when you inspect it, you're outside of the let
17:54	technomancy	which is a different scope from what slime was seeing
17:54	ts00000	ah, I got it
17:54	ts00000	well, this is the problem though
17:54	ts00000	the reason I investigated this in the first place was because I couldn't load clojure.http.client
17:54	technomancy	ts00000: did you add the jar after launching the session?
17:54	ts00000	no
17:54	ts00000	:)
17:54	ts00000	but let me see if it works now
17:55	ts00000	wow, how fantastically convenient
17:55	ts00000	it's there
17:55	ts00000	:-)
17:56	ts00000	technomancy: now, you were saying that I should be able to require resourcefully inside a repl, with the :as but without the namespace, although of course the namespacing is the preferred way to do it, right?
17:57	ts00000	but the syntax for that doesn't seem to be (require 'clojure.http.resourcefully :as resourcefully) - what is the right syntax?
17:57	technomancy	try wrapping everything after "require" in []
17:58	ts00000	well, if I do it with the ', it says unable to resolve symbol resourcefully in this context, if I do it without the ', it can't find the class
17:59	technomancy	ts00000: should be: (ns eveloci.core (:require [clojure.http.resourcefully :as resourcefully]))
17:59	technomancy	ns is a macro, so you don't need to quote anything
18:00	ts00000	if I want to do it without changing the namespace, can that be done?
18:00	ts00000	like I just want to mess around with it in the repl.
18:00	technomancy	right, if you want to do it in the repl, you'll also need to quote the final resourcefully
18:00	ts00000	ah, ok
18:00	ts00000	that's what I was missing
18:00	technomancy	otherwise it treats it as a variable and tries to look up the value
18:00	ts00000	thanks so much :)
18:00	technomancy	but you want the symbol itself
18:00	technomancy	np
18:00	hiredman	uh
18:00	jcromartie	what is this all about? http://gist.github.com/282385
18:00	jcromartie	[B ?
18:00	hiredman	you were missing the whole vector
18:01	hiredman	,(class (make-array Byte/TYPE 1))
18:01	clojurebot	[B
18:01	lpetit	chouser: yes, but has no story to handle incorrect input, and no story to handle comments, literal metadata, etc.
18:01	hiredman	jcromartie: you need to call .getBytes on the string
18:01	jcromartie	hmm
18:02	jcromartie	public static byte[] decodeBase64(String base64String)
18:02	jcromartie	so what's the problem, the return value?
18:02	hiredman	jcromartie: no idea
18:02	jcromartie	.getBytes works, by the way... I'm just confused as to why the String method doesn't
18:02	hiredman	the string method wasn't being called
18:03	jcromartie	yeah
18:03	hiredman	possibly you have an old version of the library without it
18:03	hiredman	what library is that?
18:03	jcromartie	Apache Commons Codec
18:03	ts00000	ah: and so when I try to access (clojure.contrib.zip-filter), I also have to use the symbol to get at the functions
18:03	ts00000	('clojure.contrib.zip-filter/xml-)
18:03	ts00000	right?
18:04	hiredman	,(import 'org.apache.commons.codec.binary.Base64
18:04	clojurebot	EOF while reading
18:05	hiredman	,(import 'org.apache.commons.codec.binary.Base64)
18:05	clojurebot	java.lang.ClassNotFoundException: org.apache.commons.codec.binary.Base64
18:05	hiredman	bah
18:05	hiredman	,(doc show)
18:05	clojurebot	"clojure.contrib.repl-utils/show;[[x] [x selector]]; With one arg prints all static and instance members of x or (class x). Each member is listed with a number which can be given as 'selector' to return the member object -- the REPL will print more details for that member. The selector also may be a string or regex, in which case only members whose names match 'selector' as a case-insensitive regex will be printed. Finall
18:08	jcromartie	ooh
18:08	jcromartie	that's awesome
18:12	technomancy	jcromartie: that's nothing... in slime use C-c S-i to pull up the inspector
18:12	technomancy	it's hyperlinked
18:12	alexyk	how do I access a static field of a class?
18:13	alexyk	Java's
18:15	ts00000	is there any way to get at private documentation from the repl?
18:18	joegg	alexyk: (BigDecimal/ZERO)
18:19	joegg	Is that what you mean?
18:19	alexyk	joegg: yeah... for some reason I get an error, Unable to find static field, on a class which must have it
18:20	alexyk	how can I use reflection to see what's inside a class in repl?
18:20	alexyk	it's a public static final int BLAH = 8
18:29	joegg	,(sequence (.getFields (class "")))
18:29	clojurebot	(#<Field public static final java.util.Comparator java.lang.String.CASE_INSENSITIVE_ORDER>)
18:29	joegg	alexky: That might help, I guess.
18:29	joegg	Oops, sorry for typoing your handle.
18:30	joegg	You can also just use the name of the class:
18:30	joegg	,(sequence (.getFields BigInteger))
18:30	clojurebot	(#<Field public static final java.math.BigInteger java.math.BigInteger.ZERO> #<Field public static final java.math.BigInteger java.math.BigInteger.ONE> #<Field public static final java.math.BigInteger java.math.BigInteger.TEN>)
18:30	joegg	Is that helping?
18:31	joegg	Also, if someone knows a better way, please correct me, as I'm just a beginner.
18:32	alexyk	will try, thx!
18:35	dabd	I'm trying to pass java HashMap to a clojure function and I get the following error: java.lang.ClassCastException: java.util.HashMap cannot be cast to clojure.lang.IPersistentCollection
18:36	dabd	what type of Map should I pass to the Clojure function?
18:36	arohner	dabd: try a PersistentMap
18:36	dabd	arohner: thx
18:36	arohner	hrm, that might have been bad advice
18:37	arohner	can you paste what you're trying to do?
18:39	dabd	arohner I'm trying this invoke(PersistentHashMap.create(map));
18:39	dabd	and map is a Java HashMap
18:39	arohner	invoke? are you calling from java?
18:39	dabd	the invoked Clojure function excepts a Clojure Map
18:39	dabd	yes I am calling from Java
18:40	dabd	I am implementing a Web Service that uses Java API for RESTful WS and unfortunately since it relies on Java annotations I have to write some Java code, so I need to invoke Clojure from Java
18:41	arohner	I know (into {} (seq map)) will work. Looking for a better way now
18:42	jcromartie	dabd: invoke takes a function, PersistentHashMap.create(map) returns a new PersistentHashMap
18:42	jcromartie	invoke takes IFn
18:42	jcromartie	so your map is being cast to an IFn and called
18:43	jcromartie	the equivalent clojure would be ((map m))
18:43	hiredman	jcromartie: un
18:43	hiredman	invoke is a method on a fn
18:43	jcromartie	dur
18:43	hiredman	it may or may not take a function
18:43	jcromartie	sorry
18:44	arohner	dabd: I think the java equivalent of (into {} (seq your-map)) is your best bet
18:45	dabd	arohner: I think that Java equivalent might be PersistentHashMap.create(map) where map is a Java HashMap
18:45	arohner	oh yeah, I missed that
18:45	arohner	yeah, that looks better
18:47	arohner	can you paste the whole of your invoke() line?
18:47	dabd	invoke seems to accept a number of Java Objects which are the arguments to pass to the Clojure function
18:47	hiredman	correct
18:47	dabd	arohner: Object result = groupbytf.invoke(PersistentHashMap.create(map));
18:47	dabd	where groupbytf is a clojure.lang.Var
18:47	hiredman	~def c.l.PersistentHashMap
18:48	hiredman	and you still get the exception?
18:49	dabd	no I'm past that. Now I have to debug the next error :-) thx
18:55	raz__	Does anyone know if the clojure compiler can be used to generate the AST or some other representation of clojure source code? I know there are classes like DefExpr or AssignmentExpr and so on but it looks like the compiler just keeps those to itself and does not expose the AST. I'd like to build a toy refactoring tool and a model of the source code would be very useful
19:00	lypanov	chouser: (and the other author) man joy of f'n rules.
19:01	ctdean	You could use a tool like jad to decompile the .class file that clojure generates
19:02	lypanov	ctdean: i've heard that thats not a great way of trying to use gwt to go from clojure to js
19:02	lypanov	various complications mean it sounds like its easiest to take the ast and translate directly
19:03	ctdean	lypanov: sounds like you know more about this than me already :)
19:04	ctdean	I used jad when I was working on one of the Scheme to jvm compilers. It was a useful debugging tool, but that's all I ever used it for
19:06	fiatmoney	(println "hello clojurebot")
19:06	raz__	try with a comma before it
19:06	raz__	,(println "like this?")
19:07	clojurebot	like this?
19:07	fiatmoney	,(println "hello clojurebot")
19:07	clojurebot	hello clojurebot
19:07	fiatmoney	ah, cool, thanks
19:07	raz__	guess it pays of to read #clojure logs instead of learning for exams
19:07	raz__	off*
19:07	lypanov	hehe
19:21	raz__	lypanov: there seems to be a parser in the 'La Clojure' Intellij plugin. Check the parser namespace. It uses the apache 2 license. The repository is here: git://git.jetbrains.org/idea/clojure-plugin.git
20:05	arohner	Raz_: why do you need a separate AST than (read)'ing source?
20:06	chouser	Raynes: you can indeed get at the analysis tree, which has richer semantic information than just what 'read' returns
20:07	chouser	sorry, that was for Raz_
20:07	chouser	oh. actually, raz__, but he's gone
20:07	Raynes	chouser: It's okay. I understand. You love my name so much, you can't help but say it every chance you get. <3
20:17	ts00000	chouser: do you have any idea what 'Unable to resolve symbol: text in this context' might mean while using zip-filter?
20:17	ts00000	I have some xml with an attr of name, could it be getting hung up on that?
20:32	chouser	ts00000: it probably means you're using the symbol 'text' someplace where it isn't defined
20:32	chouser	zip-filter.xml defines a fn named text I believe. are you :use'ing it?
20:38	ts00000	chouser: i figured out where I went wrong by directly qualifying it; but now if I have some random xml def'd that has a foo attr with a value of bar, and I try to xml-> thexmlvar :foo, the repl tells me a string can't be cast to an iobj
21:08	ts00000	i'm really close to figuring this out. I have a function that returns a map (it comes from http.client). i'm trying to parse it but I think xml/parse isn't accepting the map because an illegalargumentexception is thrown. how do I get it into something parseable?
21:09	hiredman	…
21:09	hiredman	have you read the docstring on xml/parse?
21:09	hiredman	does it say anything that would lead you to believe it takes a map?
21:11	ts00000	obviously not, but when I try to feed it a string, it does something I don't expect.
21:11	ts00000	like (xml/parse (str (:body-seq testfunc)))
21:11	hiredman	,(doc clojure.xml/parse)
21:11	clojurebot	"([s] [s startparse]); Parses and loads the source s, which can be a File, InputStream or String naming a URI. Returns a tree of the xml/element struct-map, which has the keys :tag, :attrs, and :content. and accessor fns tag, attrs, and content. Other parsers can be supplied by passing startparse, a fn taking a source and a ContentHandler and returning a parser"
21:11	hiredman	"or String naming a URI"
21:12	ts00000	ok, so can I somehow smash my already-retrieved stuff into an inputstream?
21:12	hiredman	.getBytes and java.io.ByteArrayInputstream
21:14	ctdean	,(doc with-in-str)
21:14	clojurebot	"([s & body]); Evaluates body in a context in which in is bound to a fresh StringReader initialized with the string s."
21:17	Raynes	ts00000: (ByteArrayInputStream. (.getBytes stuff "UTF-8"))
21:20	hiredman	#/. is like window 11, so escape+number key doesn't find it
21:20	hiredman	erp, mischan
21:24	ts00000	i've got to be making this out to be far more complex than it should be :/
21:27	ts00000	in my map, the body of the returned xml is a sequence
21:31	dabd	is anyone able to inspect/watch values when debugging Clojure code with netbeans?
21:41	alexyk	how do you translate this into clojure: collection.find( query ).skip( 1000 ).limit( 100 ).toArray()
21:41	alexyk	is it what .. are for?
21:42	chouser	sure. or ->
21:42	hiredman	(-> collection filter drop take)
21:42	chouser	(-> collection (.find query) (.skip 1000) (.limit 100) .toArray)
21:43	alexyk	and what .. would look like?
21:43	chouser	(.. collection (find query) (skip 1000) (limit 100) toArray)
21:43	alexyk	hard to tell what's nicer
21:43	chouser	that is, it suddenly becomes less clear if find is a method or a fn, and samke with skip and limit
21:44	chouser	and you can no longer include regular clojure fns in the pipeline.
21:45	alexyk	oh, I need further trickery: if skip or limit parameters are nil, the whole skip or limit call must be avoided. How can I account for it?
21:45	chouser	you want to just return nil then instead of doing the rest of the chain?
21:46	alexyk	no -- find is always done; skip or limit should be simply skpped over if their arg is nil
21:46	cemerick	dabd: inspect, yes -- you can't set clojure watches though, AFAIK
21:46	alexyk	teh final toArray is also always done
21:47	chouser	if their arg is nil instead of 1000?
21:47	alexyk	yep
21:48	alexyk	is it a use case for a macro?
21:50	chouser	(-> c (.find q) (#(if n (.skip % n) %)) ...)
21:50	chouser	ick
21:50	dabd	cemerick: say u have a breakpoint on a Clojure line. How do you inspect a value?
21:50	alexyk	yackety-yack
21:50	alexyk	or yuckety-yuck
21:51	cemerick	dabd: open the 'variables' tab and dig around
21:52	alexyk	never wrote a macro; but perhaps one can be used for (#(if n (~method % n) %)) ?
21:52	dabd	cemerick: thx
21:53	cemerick	dabd: np -- FYI, make sure you have a tostring column in your variables table -- that should print out nicely-formatted representations of standard data structures, etc.
21:55	dabd	cemerick: thx for the tip!
21:55	alexyk	chouser: makes sense? what would the macro look like?
21:56	chouser	hm.. yes, a macro might work there.
22:02	alexyk	I'd appreciate a sample macro as an example
22:03	alexyk	would be a starting point!
22:04	chouser	well, the recipe is: first write the output by hand
22:07	alexyk	ok
22:07	ts00000	any ideas where i'm going wrong? http://pastie.org/787642
22:08	alexyk	chouser: to that's essentially (method coll n) or nil
22:09	ts00000	testfunc returns something like {:body-seq ("<?xml version='1.0' encoding='UTF-8'?>" "<name>xxx</name>")}
22:09	ts00000	but I can't seem to get at the text of <name>
22:10	chouser	alexyk: (let [a nil] (-> 5 ((fn [x] (if a (+ x a) x)))))
22:10	alexyk	chouser: something like this? (defmacro methornil [coll method n] `(#(if ~n (~method ~coll ~n) ~coll)))
22:10	alexyk	I
22:10	alexyk	'
22:10	alexyk	ve made it up
22:11	alexyk	so it doesn't work yet :)
22:12	chouser	I don't think you can use #() in a macro expansion
22:13	somnium`	maybe smthing like (defmacro ?#&! [arg pred f] `(if ~pred (~f ~arg) ~arg))
22:13	somnium`	every time I use clojure.walk I seem to write something similar
22:14	chouser	we're skipping a step. The next step is an example usage.
22:14	somnium`	my bad :)
22:14	chouser	:-)
22:14	chouser	(let [a nil] (-.
22:15	chouser	(let [a nil] (-> 5 (foo + a))) perhaps?
22:17	chouser	so, (defmacro foo [fnname & args] ...) right?
22:17	alexyk	yep
22:18	alexyk	which will then expand to the icky (#(if...)) thing
22:20	chouser	hm.. actually, looking at that example usage, I don't think it needs to be a macro at all
22:22	alexyk	I want this form: (-> [1 2 3] (methornil take 2))
22:22	alexyk	if 2 is not nil, take is applied to [1 2 3], otherwise the original is returned
22:22	alexyk	methornil is "method or nil"
22:22	alexyk	a patented medication against macrophobia
22:23	chouser	(defn foo [x f a] (if a (f x a) x))
22:24	alexyk	so no need for macros at all
22:24	chouser	:-)
22:24	chouser	sorry
22:24	alexyk	pity
22:24	alexyk	methornil expired
22:24	chouser	(let [a nil] (-> 5 (foo + a)) ;=> 5
22:24	chouser	(let [a 9] (-> 5 (foo + a))) ;=> 14
22:25	alexyk	indeed
22:25	alexyk	I'll call it methornil anyways :)
22:25	chouser	sure
22:26	alexyk	I stylistically prefer ->> to ->, is there any logic here to pick ->?
22:26	alexyk	I can reorder methornil's arg order
22:26	chouser	heh. yep.
22:26	chouser	oops. I'm not writing.
22:27	alexyk	?
22:27	chouser	the book
22:27	alexyk	ah
22:28	somnium`	alexyk: how about <-??->
22:28	alexyk	what's that?
22:28	somnium`	(its shorter than methornil)
22:28	alexyk	but it's not medicinal-sounding
22:28	alexyk	somnium`: I've tried to pick up mongo-specifics in the separate chat, so you see that?
22:32	ts00000	wow, how counterintuitive, finally got it to work
22:33	ts00000	what a pain in the royal ass :/
22:37	ts00000	chouser: now I have one that should be very easy to answer: why doesn't the root tag need to be declared when you're accessing an attribute with zip-filter.xml? I can't even get at the root tag
22:37	defn	Ask your Dr. of Computer Science if Methoril is right for you.
22:38	chouser	there's always one root, so you can just skip it
22:38	ts00000	what if there are attrs on the root I want to get at?
22:38	ts00000	e.g. <s3-api version="2"> ....body.... </s3-api>
22:38	chouser	oooh! hmph!
22:38	ts00000	this is one of the things that has been confusing me all night and just had the eureka moment
22:39	ts00000	by removing the root element all of a sudden all my blanks actually had data
22:39	ts00000	:)
22:44	ts00000	Error Message %ADJ-5-PARENT: Midchain parent maintenance for [chars] - [chars]
22:44	ts00000	Explanation A midchain adjacency failed to stack onto an output chain because a loop was detected. Traffic through the adjacency will be dropped until the adjacency is restacked. This condition is typically transient and is resolved by the control plane that drives the stacking. For example, if an IP tunnel destination resolves through the tunnel transiently this message will appear. The situation would be resolved either by learning the tunnel destination t
22:44	ts00000	sorry :/
22:44	chouser	ts00000: oh, you can still pull attrs from the root element
22:44	ts00000	ts00000: how?
22:44	chouser	when you put a tag like :foo, it descends a level an looks for a tag there.
22:46	ts00000	chouser: in my case, i'm trying (xml-> blah :s3-api (attr :version)) - wrong way?
22:46	ts00000	s3-api is the root of the tree
22:47	chouser	just drop the :s3-api
22:47	chouser	you're already at the root of the tree
22:47	ts00000	ah!
22:48	ts00000	I got it now
22:48	ts00000	perfect
22:49	ts00000	thanks so much for being patient
22:49	ts00000	i think it does rescan and walk it after the timers are done
22:49	alexyk	,(letfn [(methornil [x f a] (if a (f x a) x))] (methornil [1 2 3] take 2))
22:49	clojurebot	java.lang.ClassCastException: clojure.lang.PersistentVector cannot be cast to java.lang.Number
22:50	chouser	sure. I actually find zip-filter fragile to use as well. I'm not sure how to fix it though. :-/
22:50	alexyk	why error?
22:50	ts00000	i don't think it needs to be fixed
22:50	ts00000	it's just the most rapid way to prototype what I want to do, when what I should be doing is going deeper with just parsing out the tree itself
22:51	ts00000	if I were to offer only one suggestion as a complete newbie coming to clojure, i'd say that in the absence of more error messages, there needs to be a more obvious way to trace and figure out why things are going wrong. the repl is great but it is unforgiving.
22:51	chouser	yeah, zip-filter just give you nils, and you're left flailing around
22:51	ts00000	let me rephrase that; slime+repl is great but unforgiving
22:51	alexyk	ts00000: I saved a defn into a file, load-file it, boom -- printStackStrace prints the actual file:line, not no-source-file:0 :)
22:51	ts00000	yes, there is a lot of flailing around in clojure I have noticed, it lets you do things that are not otherwise correct
22:52	hiredman	tree-map + filter works pretty well
22:52	ts00000	alexyk: the no-source-file:0 is actually helpful to me when determining what's going on int he repl versus the file
22:52	alexyk	ts00000: unless you pasted 25 lines
22:52	chouser	alexyk: your args to 'take' are backwards
22:52	ts00000	alexyk: but look at it this way, as a newcomer, your choices of IDEs are limited, and none of them are particularly helpful, and a great many newcomers are left choosing emacs, which is even more of an issue
22:52	ts00000	alexyk: good point
22:52	alexyk	chouser: doh
22:53	alexyk	ts00000: newbies should stay away from IDEs
22:53	alexyk	wasting time on Emacs unless you know it or some GUIs is silly... raw text editor and repl and forge ahead!
22:53	ts00000	yes, but developing without one, especially for someone new, is difficult :-)
22:53	alexyk	my take at least
22:53	hiredman	http://github.com/hiredman/clojurebot/blob/master/src/hiredman/clojurebot/clojars.clj <-- clojurebot scraping for the recently on clojars notices
22:55	alexyk	hiredman: how about capturing outcries "clojars search is broken" and forwarding it to the clojars-ers? :)
22:56	hiredman	shrug
22:57	alexyk	chouser: is there a "flip" adatper on things like take?
22:57	alexyk	adapter
22:58	alexyk	so I'd have only one methornil and call it with (flip take) or something
22:58	chouser	#(foo %2 %1))
22:59	alexyk	ah
23:00	chouser	,(-> [a 5] (let a))
23:00	clojurebot	5
23:01	arohner	chouser: that's a little crazy
23:03	alexyk	what's (let a) ?
23:03	arohner	alexyk: (let a) doesn't work, but the macro turns that into (let [a 5] a)
23:05	alexyk	don't show it to the scala people :)
23:06	arohner	yeah
23:06	arohner	,(macroexpand '(-> [a 5] (let a))
23:06	clojurebot	EOF while reading
23:07	arohner	(macroexpand '(-> [a 5] (let a)))
23:07	arohner	,(macroexpand '(-> [a 5] (let a)))
23:07	clojurebot	(let* [a 5] a)
23:07	chouser	,((->> (+ a b) (fn [a b])) 4 5)
23:07	clojurebot	9
23:08	arohner	ok now you're scaring me
23:08	arohner	,(macroexpand '((->> (+ a b) (fn [a b])) 4 5))
23:08	clojurebot	((->> (+ a b) (fn [a b])) 4 5)
23:08	chouser	,(->> (inc a) (let [a 5]))
23:08	clojurebot	6
23:09	chouser	actually, it would be better to show this to nobody at all.
23:09	chouser	,(->> a (+ 5) (let [a 5]))
23:09	clojurebot	10
23:10	joegg	,(->> "Ooh, me too!" (println))
23:10	clojurebot	Ooh, me too!
23:10	joegg	YAY!
23:10	chouser	if there's only one thing, you don't even need parens
23:11	joegg	Ah, because of the "makes it a list" part...
23:11	joegg	Sweet.
23:12	arohner	I need a random arrow. Takes your form and stick the first argument in a random place in the list...
23:13	arohner	wraps it in try catches, and tries again, until you make a form that doesn't throw an exception
23:13	alexyk	arohner: or even into a random orifice of the programmer
23:14	alexyk	"an arrow of doom"
23:14	ts00000	where is the ->> better explained/documented?
23:14	ts00000	i've looked at the doc string and in programming clojure but that doesn't cover that very well
23:15	chouser	do not look at the examples I was just giving.
23:15	alexyk	chouser: too late
23:15	chouser	they're a horrible abuse
23:15	ts00000	<- eyes covered
23:15	chouser	I apologize for even mentioning them
23:15	ts00000	i'm just curious, want to learn more
23:15	chouser	and then tweeting
23:15	chouser	,(->> (range 30) (filter even?) (drop 10))
23:16	clojurebot	(20 22 24 26 28)
23:16	chouser	that's a better example
23:16	chouser	each form is inserted as the final argument of the next form
23:16	chouser	so the above is the same as (->> (filter even? (range 30)) (drop 10))
23:16	alexyk	every time a crooked ->> is used, a frog dies in the Amazon
23:16	chouser	which is the same as (drop 10 (filter even? (range 30)))
23:17	ts00000	why would you want to use that as opposed to the (drop 10 ...) ?
23:17	chouser	this will be explored in detail in chapter 7
23:17	chouser	:-)
23:17	ts00000	of your new book?
23:18	ts00000	joy of closure meap?
23:18	chouser	ts00000: it allows you to read it left-to-right, instead of inside-out. Can also help reduce nesting levels. Mostly a matter of taste.
23:18	chouser	ts00000: yep. http://joyofclojure.com/
23:18	ts00000	it's on the list for this weekend actually :)
23:19	chouser	except the TOC there will be revised next time the MEAP is updated
23:19	chouser	the version that's available now is undergoing major surgery by fogus's deft hand
23:20	alexyk	since clojure is lisp-2, function literals mean themselves, right? so I could call (methornil coll take 2). Now what if instead of take it's (methornil obj .method n) -- can I still invoke with literal method name .method?
23:20	arohner	clojure is not a lisp-2
23:20	alexyk	lisp-1 I meant
23:20	alexyk	my understanding of the first part of my own utterance is infirm
23:20	alexyk	that's the gist I gathered from the past here :)
23:21	arohner	lisp-1 means that variables and functions live in the same namespace
23:21	arohner	in lisp-2s, you can have a variable foo, and a function foo, and they don't step on each other
23:21	alexyk	right; does it affect the fact that you can supply a function as a parameter by just writing its name?
23:21	arohner	yes
23:22	alexyk	ok, that's solved. Now about .method?
23:22	chouser	.foo is not a function
23:22	chouser	unfortunately
23:22	alexyk	arrgh
23:22	chouser	it's a special form
23:22	alexyk	methornil's just become obsolete
23:22	chouser	but this is actually a good thing!
23:22	chouser	because now you have an excuse to write methornil as a macro
23:23	arohner	you're wanting to pass a java method around to clojure functions?
23:23	alexyk	yep
23:23	alexyk	chouser: yay! let's do it
23:23	alexyk	back to the macros
23:24	alexyk	so I need to write a macro methornil, equivalent to the defn: (defn methornil [x f a] (if a (f x a) x)), which takes java methods as f
23:25	chouser	(defmacro methornil [x f a] `(if ~a (~f ~x ~a) ~x))
23:25	chouser	except that expands a and x twice each, which could potentially cause problems
23:26	alexyk	chouser: is there like a macro val which stores the single expansion for reuse?
23:26	arohner	alexyk: your friend 'let' will do that
23:26	chouser	you just have your macro expand to something like (let [x-val x] ...)
23:27	arohner	(defmacro methodornil [x f a] `(let [a# ~a x# ~x] (if a# (~f x# a#) x#))
23:27	alexyk	right
23:27	alexyk	what's a# and x#?
23:28	alexyk	ah, just single expansions
23:28	alexyk	chouser: so how would you summarize why exactly we need macro for both methods and functions? :)
23:28	alexyk	before you go...
23:28	arohner	nobody's ever told me I'm capable at clojure before
23:29	arohner	alexyk: you need a macro before java methods are not first class functions
23:29	alexyk	arohner: using # is a sign of maturity, also thwarts perl and ruby and python people into stupefaction :)
23:29	arohner	(.foo obj) is a special form; you use the macro to produce those
23:30	alexyk	right
23:30	alexyk	somnium`: perl people turn off like androids upon seeing #
23:30	alexyk	and skip to the next line
23:32	alexyk	ok, finally a case for macros. somnium`, consider this: I switched to clojure 'cause congomongo is better at mongo than scala for data; now it has lead me to learn macros. What else is in store?
23:33	alexyk	the next application of congomongo is general relativity probably
23:34	somnium`	alexyk: once you get comfortable with macros, you may find any non-lisp to feel unpleasantly lacking in expressiveness
23:35	somnium`	that, or general relativity I guess
23:36	joegg	alexky: one of the main things that macros allow you to do is to create new first class syntax, which I think you're already picking up on.
23:36	joegg	Darn, again, typo'd your name.
23:36	alexyk	np)
23:36	joegg	Anyway, (if...) is a macro that just calls (cond...), more or less.
23:37	joegg	(Also, I'm a beginner, so if I end up saying something wrong, anyone can feel free to correct me please.)
23:37	somnium`	,(macroexpand '(cond true :foo))
23:37	clojurebot	(if true :foo (clojure.core/cond))
23:37	alexyk	how can you check what's a macro?
23:37	joegg	Now, one thing that I've always wanted in javascript/java/etc is a while/else.
23:37	arohner	alexyk: the metadata of the var
23:37	arohner	,(meta (var cond))
23:37	clojurebot	{:macro true, :ns #<Namespace clojure.core>, :name cond, :file "clojure/core.clj", :line 400, :arglists ([& clauses]), :doc "Takes a set of test/expr pairs. It evaluates each test one at a\n time. If a test returns logical true, cond evaluates and returns\n the value of the corresponding expr and doesn't evaluate any of the\n other tests or exprs. (cond) returns nil."}
23:37	tomoj	it tells you in (doc cond) too
23:38	joegg	while(foo) { } else { }, where the else is executed only if the while was never executed.
23:38	arohner	oh, right
23:38	joegg	In javascript, I couldn't have that, unless I wanted to write my own implementation.
23:38	tomoj	macro? would have to be a macro, eh?
23:38	joegg	Or, fake it, horribly, using functions.
23:38	joegg	In clojure, I can create while/else using macros.
23:39	joegg	And it has the same (total lack of) syntax as everything else, it's not some second class thing.
23:39	defn	hi all
23:40	defn	ls
23:40	joegg	alexyk: Does that make sense? (also, just found out I can tab-complete nicks.)
23:42	alexyk	yeah
23:43	alexyk	defn: we just decided macro is a better nick
23:50	joegg	Ooh, while-else, implemented (crappily):
23:50	joegg	(defmacro while-else [test body else] `(if ~test (while ~test ~body) ~else)))
23:51	joegg	Can anyone tell me if I've done something wrong on that?
23:51	joegg	It appears to work fine here, but I would love to know if there's something I could do differently or better.