#clojure – 2010-05-18

2010-05-18

00:12	jColeChanged	How would I create a function which would return 1 the first time it was called, 2 the second time, 3 the third ect
00:14	rava	jcolchanged: just have the function increment a counter var
00:20	turbofail	jcolchanged: what you may really want is an infinite stream that counts upwards
00:21	turbofail	but if it's not then do what rava said
00:22	jColeChanged	I'm actually confused as to how to persist assignment between function calls.
00:23	TheBusby	(def current-count (ref 0)) then, (defn inc-count [] (dosync (ref-set current-count (inc @current-count))))
00:24	jColeChanged	Thanks.
00:26	rava	or use alter
00:58	mmarczyk	on 1.2, (deftype Counter [^{:volatile-mutable true} cnt] clojure.lang.IFn (invoke [this] (set! cnt (inc cnt)))) is also a possibility
01:29	kanak	Hi, in Programming Clojure's chapter on refs, the following snippet is called "bad idea":
01:29	kanak
01:29	kanak	; bad idea
01:29	kanak	(defn naive-add-message [msg]
01:29	kanak	(dosync (ref-set messages (cons msg @messages))))
01:29	kanak	is it a bad idea because accessing and updating are not a single step?
01:36	rava	Essentially, yes. or at least that's how I understand it. If there's no need to deref the var first, like in the example where you don't care about the contents..you're just appending, it doesn't make sense to have to deref and re-set the ref.
01:36	Chousuke	I suppose it's a bad idea because you could just use alter or commute (if order doesn't matter)
01:47	joshua-choi	clojure.contrib.seq/separate is ostensibly useful, but I find that in all cases that I want to use it, I should use (map #(if ...) s) instead. Also, it crawls twice.
01:54	G0SUB	Chousuke, ping
01:56	LauJensen	Morning all
01:56	mmarczyk	hi Lau
01:56	mmarczyk	nice work on the site -- and the blog post :-)
01:56	G0SUB	LauJensen
01:56	LauJensen	Thanks a lot mmarczyk !
01:56	mmarczyk	(and btw, thanks for the corrected classpath-building script :-))
01:57	LauJensen	np - it went into my 'deploy' script which converts the old site, builds the new and rsyncs it to the server
01:57	mmarczyk	cool :-)
01:57	G0SUB	LauJensen, something is wrong with your feed URLs. they are going to the CSS file.
01:58	LauJensen	G0SUB: Im on that right now actually
01:58	LauJensen	The way I inject CSS matches <link rel="atom" as well - gimme a couple of minz :)
01:58	rdsr	joshua-choi: how is (split with #(...) s) different from separate?
01:58	G0SUB	LauJensen, sure. I was surprised because your posts are not appearing on Planet Clojure.
01:59	LauJensen	I appologize for the inconvinience
01:59	joshua-choi	rdsr: You mean, in traversing the sequence twice? I'm not quite sure. :\|
01:59	G0SUB	LauJensen, no problem man :) take your time.
02:00	rdsr	joshua-choi: in terms of functionality, maybe I can't think of any good examples
02:00	rdsr	a little thick headed today I guess :(
02:00	rava	greetings all
02:02	rava	LauJensen: really dig the blog
02:02	LauJensen	rava: the blog as in content or the design?
02:02	rava	LauJensen: both :)
02:02	LauJensen	rava: great, cool, thanks :)
02:03	rava	LauJensen: http://www.bestinclass.dk/index.clj/blog.html that link goes to 404
02:03	rdsr	oh sorry, just realized my mistake
02:03	LauJensen	rava: true, there's no file there
02:04	rava	LauJensen: its all sorts of helpful to have some well written code + commentary to read through as i'm teaching myself clj. the hardest part for me learning clj is wrapping my head around the idioms of functional programming.
02:04	G0SUB	hmm... Apress vs. Manning vs. Packt
02:04	G0SUB	argh!
02:05	LauJensen	rava: yes that is a painful but worthwhile experience :)
02:07	alexyk	mmarczyk: so every?-based version is much slower than a loop one: http://paste.pocoo.org/show/215132/
02:07	alexyk	sometimes FP is pretty but slow, even though it allows for pmap!
02:08	LauJensen	Could somebody do me a favor and try to and leave a comment on my site please
02:08	G0SUB	LauJensen, yeah
02:08	LauJensen	thanks
02:09	G0SUB	LauJensen, done.
02:09	LauJensen	thanks
02:12	LauJensen	G0SUB: Got it thanks
02:17	mmarczyk	alexyk: could you please use some line breaks in there... but anyway, as far as I can see (without the line breaks!), the loop-based version doesn't include pmap, while the every?-based version does
02:19	mmarczyk	um, whoops, next time...
02:19	turbofail	,(doc ->>)
02:19	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."
02:23	LauJensen	G0SUB: moderated
02:24	LauJensen	mmarczyk: if thats a performance enhanced loop, I'd expect to see some hinted ints and transients? :)
02:28	turbofail	hm... that difference in performance is a little surprising
02:35	mmarczyk	LauJensen: not my loop, I only provided a few ideas :-)
02:35	LauJensen	aha - so you're the mastermind :)
02:36	mmarczyk	well, hardly -- I haven't managed to effect a nested ifs -> cond switch ;-)
02:37	Chousuke	how many dreps are there?
02:39	turbofail	dunno... the guy left
02:39	mmarczyk	no idea, you'll need to ask alexyk next time
02:39	Chousuke	the pmap overhead might be killing it if the day seqs are short but there are many dreps :/
02:40	Chousuke	also laziness does add its own overhead even if it didn't use pmap, but it shouldn't be that bad.
02:46	Chousuke	(every? true (map >= s (cons (first s) s)))) wonder if this could be replaced with (apply <= s)
02:46	turbofail	probably can
02:47	mmarczyk	hah, right :-)
02:47	G0SUB	Chousuke, can I PM you? something OT to discuss.
02:48	Chousuke	sure.
02:48	G0SUB	thanks
02:50	rava	LauJensen: I can't seem to find your blog's feed url on your site
02:51	johnmn3	hello
02:51	G0SUB	chouser, ping
02:51	rava	greetings johnmn3
02:52	johnmn3	I'm toying around with a rudimentary clojure code editor. I'm thinking about putting some kind of inspector on the left side
02:53	johnmn3	what do you guys think the most useful inspector would look like?
02:53	johnmn3	I'm thinking something akin to Rich Hickey's inspect-tree
02:54	johnmn3	but where you can drill down into an object... perhaps do a macro expand? or maybe collapsed nodes showed a short string from it's docstring
02:55	johnmn3	I'm not really sure though.
02:58	johnmn3	I really like eclipse's class inspector.. where you can drill down, then you find an object in there you'd like to explore and open it in another window
02:58	johnmn3	and look at all the fields and methods.
03:01	johnmn3	anybody have any preferrences?
03:01	johnmn3	or any preferences?
03:18	G0SUB	what is the difference between dev-dependencies and dependencies in lein?
03:18	G0SUB	why does swank-clojure have clojure 1.2.x as a dev-dependency? does it affect projects using clojure 1.1.0 ?
03:20	rava	LauJensen: on your web scraper blog entry, what ns contains that get-page function?
03:20	lancepantz_	G0SUB: dev-dependencies are not transitive
03:21	lancepantz_	G0SUB: in other words, if a project you depend on has a dev-dep, when you do deps it will not get pulled down
03:26	G0SUB	lancepantz_, OK. so swank-clojure 1.2.1 should work fine with clojure 1.1.0, right?
03:27	lancepantz_	i'm not sure
03:27	lancepantz_	i think so though
03:37	G0SUB	ok
03:38	kris928	Is anyone here familiar with vimclojure?
03:40	rava	i used it for a spell, what's up?
03:42	kris928	rava: I'm not sure how to get a new repl from within vim. Non of the default keybindings appear to work for me although I don't know if I am getting my Localleader correct.
03:42	LauJensen	rava: sec
03:44	rava	kris928: i could never get the nailgun repl thing to work in vimclojure, and your local leader is usually defaulted to ','
03:44	rava	i ended up using slime.vim before just going back to emacs+slime
03:44	LauJensen	rava: That post has been a headache to me, because the html and regexes escaped Wordpress and mangled the post
03:44	kris928	rava: I think that is what mine is too, but it never does anything when I type "sr" s always triggers edit mode.
03:45	LauJensen	rava: but the text says "if search results contains the raw html output", so get-page would nowadays be called clojure.contrib.io.slurp*
03:45	rava	kris928: yup, what i ran into aswell. never found a satisfactory answer to fixing it.
03:45	kris928	rava: thanks
03:45	rava	kris928: if you're set on using vim, check out slime.vim
03:46	rava	very simple extension that just copies the marked region and outputs it to a screen session running the repl
03:46	kris928	rava: nice, I'll try that
03:47	rava	at the same time you'll keep vimclojure's documentation reflection
03:48	rava	kris928: i found it most useful to run vim, open a terminal and start screen, create the project with lein, hop into the proj dir and run lein repl
03:48	rava	kris928: <3 lein repl for handling all the classpath crud
03:48	rava	LauJensen: cool beans, thanks
03:48	kris928	yeah I like lein, but I need clojure 1.2.0 right now and lein doesn't like that
03:49	rava	kris928: why do you need 1.2?
03:49	kris928	rava: I guess I just want it. Hit a few functions that are in 1.2.0 and not earlier
03:50	rava	kris928: ah. i'm still learning a ton and haven't done anything worth while so haven't looked at 1.2 beyond protocols
03:52	kris928	rava: thanks for help. night!
03:52	rava	kris928: np, rest easy
05:44	liwp	is swank-clojure supposed to load ~/.clojure/user.clj?
05:46	liwp	I can see in swank-clojure.el that all the jars in ~/.clojure are added to the classpath, but I can't see .clojure being added or user.clj being explicitly loaded into the repl
05:51	hiredman	liwp: user.clj is loaded from the classpath by clojure
05:51	liwp	hiredman: yeah, I know that, and that works fine for me
05:52	liwp	hiredman: I just see all these posts on the web implying that user.clj gets loaded automatically for them by slime/swank-clojure/lein-swank
05:52	hiredman	liwp: oh, right
05:52	liwp	e.g. here http://stackoverflow.com/questions/2854618/using-clojure-contrib-functions-in-slime-repl
05:52	sexpbot	"Using clojure.contrib functions in slime REPL - Stack Overflow"
05:53	hiredman	people making stuff up on the internet
05:53	liwp	and I can't make it work...
05:53	liwp	hiredman: yeah that's right :)
05:53	hiredman	make what work?
05:54	liwp	hiredman: ~/.clojure/user.clj doesn't get loaded when I run slime
05:54	hiredman	is ~/.clojure on the classpath?
05:56	liwp	hiredman: probably not. The point is that it seems that other people have ~/.clojure on their classpath automatically when using slime, but I don't. So I'm trying to figure out why not.
05:56	liwp	so I'm wondering whether it's something that should work automatically or whether I need to configure something differently
05:56	liwp	hiredman: you don't use slime, do you?
05:57	hiredman	I do
05:57	hiredman	I've never used user.clj
05:57	liwp	fair enough
05:58	rava	the most use so far i've found from a user.clj file is to autoload clojure.contrib.repl-utils
05:58	liwp	I just realised that there's all these contrib goodies that are useful in the repl and I'm not using them since I can't be bothered to (use) them every time I run the repl
05:58	liwp	rava: yeah, that's what I'm looking for ;)
05:58	hiredman	shrug
05:59	rava	liwp: just add "~/.clojure" to your swank-clojure-extra-classpaths
06:00	rava	liwp: one thing i've found useful is to add "." "./src" "./classes" "./jars" to that aswell
06:00	liwp	rava: ok. I'm just wondering whether all this should work out of the box or not
06:01	rava	liwp: If it is then I've been doing it wrong :) . Even in clojurebox (emacs+slime bundle for windows) i had to manually add ~/.clojure to my classpath
06:02	liwp	rava: ok, thanks
06:03	rava	all and all, its still the jvm, so classpath munging doesn't go away
06:03	rava	and by default clojure/-main isn't going to add ~/.clojure to your class path
06:06	liwp	rava: no, but I was hoping that either swank-clojure (it adds ~/.clojure/*.jar to your classpath automatically) or lein-swank would do it for me
06:06	rava	i've tried it with lein-repl/swank and swank-clojure. I've not had any of them do it. I could be missing something though :)
06:45	bsteuber	how can I check if something implements a certain interface? not isa?, I suppose
06:45	cemerick	instance?
06:45	bsteuber	thx
06:48	bsteuber	,(instance? clojure.lang.ISeq (into-array [1 2 3]))
06:48	clojurebot	false
06:48	bsteuber	what's wring here?
06:48	cemerick	arrays aren't seqs
06:48	bsteuber	wrong
06:48	bsteuber	so what are they, then, to have first work on them?
06:48	cemerick	,(instance? clojure.lang.ISeq (seq (into-array [1 2 3])))
06:48	clojurebot	true
06:48	cemerick	but you can just do...
06:49	cemerick	,(seq? (seq (into-array [1 2 3])))
06:49	clojurebot	true
06:49	cemerick	if you only care about ISeq
06:49	bsteuber	so how can I ask if seq works on something, then?
06:49	bsteuber	or is there no such general method?
06:49	cemerick	,(doc seqable?)
06:49	clojurebot	"clojure.contrib.core/seqable?;[[x]]; Returns true if (seq x) will succeed, false otherwise."
06:49	bsteuber	(ah, nice
06:53	patrkris	this should be a simple question: which function do I use to append an element to the end of a sequence? I could use concat and wrap the element in a vector, but there's gotta be another way?
06:54	bsteuber	,(doc cons)
06:54	clojurebot	"([x seq]); Returns a new seq where x is the first element and seq is the rest."
06:54	bsteuber	,(doc conj)
06:54	clojurebot	"([coll x] [coll x & xs]); conj[oin]. Returns a new collection with the xs 'added'. (conj nil item) returns (item). The 'addition' may happen at different 'places' depending on the concrete type."
06:55	patrkris	yes, but how to always add to the end of a seq? if conj is used on a seq besides a vector, the element gets inserted as the first element
06:56	cemerick	patrkris: ensure you're using vectors if you must add to the end of the collection
06:56	bsteuber	ah, sorry
06:57	cemerick	otherwise, always adding to the end of a sequence is likely to be inefficient
06:58	patrkris	cemerick: yes - but in this case, it doesn't matter much because the collection wont contain many elements. I was just looking for a shortcut for adding an element to any seq. In which case I could 'vectorize' my seq or use concat by wrapping the element in a collection.
06:59	cemerick	patrkris: the latter is more idiomatic and efficient
06:59	patrkris	(I meant appending to a seq - i.e. at the end.)
06:59	patrkris	cemerick: ok, thanks
06:59	cemerick	Asking to be able to append to any sequence is sort of like asking for a sorted collection without the cost associated with sorting.
07:00	Chousuke	clojure doesn't provide functions for silly operations :)
07:00	patrkris	well, if you have the ability to use concat to concatenate two seqs, wouldn't it be easy (and efficient) to create a function to append an element on top of concat?
07:01	Chousuke	so appending to a sequence has to be done in a roundabout way
07:01	Chousuke	it would be easy, but it's silly, so it won't be provided for you
07:01	patrkris	heh alright :)
07:01	cemerick	hi Chousuke, how goes it?
07:02	Chousuke	I think the point of Clojure is to be the right tool for you, not a too :P
07:02	Chousuke	tool*
07:04	Chousuke	cemerick: (Silly English, what's the "it"? :P) Just fine I think. I'm going to get some food right now. :)
07:05	lpetit	Hello, what problem exactly does the recent commit "hotfix for classloading, force new loader in all cases" solve ?
07:06	lpetit	I'm asking because we have a bug in ccw involving class files being "still held" by something and maybe (maybe) it was related.
07:06	lpetit	rhickey: hello, ^^^
07:07	rhickey	lpetit: If you have a reproducible test case for your bug, please try it with the latest
07:08	rhickey	lpetit: the fix solves a problem with :reload-all and its ilk, but in general it uses finer granularity classloaders
07:08	lpetit	rhickey: that's what I intend to do (hopefully) tonight.
07:08	lpetit	rhickey: oh, so maybe not related. I'll check.
07:08	rhickey	lpetit: great! let me know how it works out
07:09	cemerick	lpetit: is there a mailing list or google group, etc. for CCW?
07:10	lpetit	cemerick: yes, listed in the homepage of ccw
07:10	lpetit	~ccw
07:10	clojurebot	ccw is http://github.com/laurentpetit/ccw
07:10	lpetit	sh***t
07:10	lpetit	~counterclockwise
07:10	clojurebot	Counterclockwise aka ccw at http://code.google.com/p/counterclockwise/
07:10	lpetit	so ccw for github, counterclockwise for google code, isn't that logic, heh ? :-)
07:11	cemerick	ah, I didn't put 2 & 2 together re: "Groups:"
07:11	lpetit	cemerick: in practice, I use both mls for annoucing new versions. But both are low traffic.
07:12	lpetit	cemerick: why ?
07:13	cemerick	lpetit: no particular reason -- just want to keep on top of things. I think CCW has a good deal of potential. What's coming in e4 may be a great set of raw materials a clojure env could do a lot with.
07:14	lpetit	cemerick: it's possible you're more informed than me concerning e4. What particular feature(s) are you thinking about ?
07:15	cemerick	lpetit: I'm not particularly well-informed either :-) IIUC, the entire UI will be accessible through a DOM-like model, making it far easier to modify/generate UI elements at runtime. Components can be styled with CSS. Take those, mix in a clojure frontend for it, and it seems a lot of things become possible.
07:18	lpetit	cemerick:I was aware of the UI being created via EMF models. What I didn't catch is the "dynamic part" of it. Seems interesting, indeed.
07:19	lpetit	I want clojure on my client side GWT application !
07:19	cemerick	heh
07:20	cemerick	lpetit: I think we'll all be flogging chouser to resurrect clojurescript soon enough. :-)
07:21	lpetit	cemerick: I didn't check #clojure as "well" as usual. What are the current informal plans for say the next 2-3 months ?
07:22	cemerick	lpetit: you mean release-wise?
07:23	lpetit	cemerick: I know about 1.2, just wondering what were the current research, if the focus remains on working on things related to make cinc become a reality (aka in the following of protocols) or more "exploratory" stuff (aka cells) ?
07:26	cemerick	lpetit: I think only rhickey knows that for sure. My impression is that cells has been shelved for a bit. There's a number of open issues w.r.t. types and protocols that I'd think would be fairly high on the list, which would likely get us closer to cinc (definable factory fns for types, maybe multiprotocols, etc). I remember seeing rhickey talking about/tinkering with readers impl'd in clojure a few weeks ago. shrug
07:28	lpetit	any news on the "problem" spotted by cgrand concerning extending protocols on existing types and concurrency ?
07:28	cemerick	lpetit: you'll have to remind me about that -- link?
07:29	lpetit	rhickey: ^^^ (protocols & concurrency) ?
07:30	lpetit	cemerick: http://groups.google.com/group/clojure-dev/browse_thread/thread/59d2f3a1703cc09
07:32	cemerick	lpetit: yeah, I've no info on that.
07:52	AWizzArd	rhickey: the DynamicClassLoader that Clojure uses... do you think you can make it one day inherit the rights of its parent ClassLoader?
07:53	AWizzArd	This would be very nice for Applets and Web Start applications. Currently it is a complex thing to get Web Start running all Clojure code.
07:54	AWizzArd	I managed to do so, and am thinking about writing a How-To for that. But the thing is: if the Clojure ClassLoader could inherit the rights of its parent, then the How-To could be greatly simplified.
07:58	rhickey	AWizzArd: what do you mean by inherit the rights?
07:58	AWizzArd	Trying to check what rights the parent has and then setting the own rights to those.
07:59	AWizzArd	Currently the default situation is that the Web Start class loader has its own rights, which can mean "all-permissions", while the Clojure ClassLoader still runs in the sandbox with only very few rights.
07:59	AWizzArd	I managed to give Clojure also full rights, so I can run anything now via Web Start (or in an applet) easily, but getting there was a long quest.
08:01	AWizzArd	If Clojure would "copy" the rights of its parent, then everybody could get started with Web Start (or applets) within 1-2 hours, without Clojure-specific tutorials. With tutorial it is a thing of 10-30 minutes.
08:03	AWizzArd	It is a quite intruiging idea to write web applications in 100% Clojure, and this is really possible :)
08:13	rhickey	lpetit: http://groups.google.com/group/clojure-dev/msg/4522fe2e4fa21f63
08:18	lpetit	rhickey: thank s!
08:18	zakwilson_	http://github.com/zakwilson/zutil-clj/blob/master/map.clj <-- request for optimization - can this be made faster?
08:19	rhickey	AWizzArd: how about suggesting a patch?
08:30	AWizzArd	rhickey: oki thanks, I will add an issue then
08:30	rhickey	AWizzArd: I don't want an issue without a patch, please
08:30	cemerick	rhickey: A couple of times last week I bumped into some odd behaviour at the REPL, where an instance of a defrecord Foo would no longer be (instance? Foo obj) after reloading the file that contained the defrecord delcaration. In those cases, (= Foo (class obj)) was no longer true. Is this expected?
08:31	cemerick	(I can imagine the old class was being GC'd, but I'd hope the instance? check would still work as I'd intuitively expect.)
08:31	AWizzArd	rhickey: I could give you patch, but currently I have no CA. Do you accept them also via fax? :)
08:32	rhickey	cemerick: the classes may be new ones with the same name. If you are keeping an older Foo class instance around, it need not be the same
08:32	rhickey	cemerick: I try to reuse the class if the definition hasn't changed, but that is an optimization, not a promise
08:35	cemerick	hrm, OK. That almost makes me want to put together a quickie defrecord-once. Very rarely am I reloading a file to change a record's slots, and I'd very much like to not have instance? checks fail in odd ways.
08:35	rhickey	cemerick: can you construct a reproducible test case?
08:36	cemerick	rhickey: I'll see what I can do.
08:37	rhickey	cemerick: the existing logic should handle the simple reload case, as obviously there is no change
08:41	cemerick	rhickey: The defrecord spec and the object were actually defined in two different namespaces (reloaded in that order). I wonder if Namespace.referenceClass was simply continuing to get the old Class?
08:43	rhickey	cemerick: but the caching should make new-class identical-to old-class
09:24	yonatan_	hello
09:25	yonatan_	i think i just ran into a bug in clojure's RegexReader
09:25	yonatan_	it seems to choke on #"\Q"\E"
09:25	yonatan_	#"\Q\"\E" works, but matches \" rather than "
09:26	yonatan_	(re-pattern "\\Q\"\\E") works as expected (matches ")
09:26	yonatan_	is this a bug or am i missing something?
09:27	hiredman	what string are you trying to match?
09:27	yonatan_	"
09:28	yonatan_	a double quote char. (re-find (re-pattern "\\Q\"\\E") "\"") works.
09:30	yonatan_	RegexReader interprets a double-quote inside a \Q...\E sequence as the end of the regexp.
09:30	yonatan_	is this the expected behaviour?
09:30	chouser	I think so. That's not really what \Q...\E means
09:30	chouser	#"\"" should work
09:31	hiredman	well, \ "quotes"
09:31	hiredman	and so does \Q \E, yes?
09:31	chouser	\Q is about making chunks of strings act as strings instead of regex metachars
09:32	yonatan_	i thought \Q...\E is supposed to treat everything in between as a literal
09:32	chouser	so if you want . to mean a period instead of "any char", you can wrap it in \Q...\E
09:33	chouser	but if you want a literal " you need to use \"
09:34	yonatan_	but you can't do that inside a \Q...\E sequens?
09:34	chouser	, #"\Q\"\E"
09:34	clojurebot	#"\Q\"\E"
09:34	yonatan_	nope
09:34	yonatan_	it matches \" not "
09:35	chouser	ah
09:35	chouser	hm
09:35	yonatan_	i ran into it trying to port your patch to las3r
09:35	yonatan_	(the clojure in flash thingie)
09:36	yonatan_	i don't know if it's a clojure issue or a jdk issue
09:37	yonatan_	but since (re-find (re-pattern "\\Q\"\\E") "\"") works i'm thinking maybe it's a bug
09:37	yonatan_	wanted to make sure before i try to fix it
09:40	chouser	well, I guess it's a soft spot in the definition. How do we want it to behave?
09:41	chouser	why do you want #"\Q\"\E" to match " instead of \" ?
09:50	yonatan_	dunno, it seems like the right thing to do. i mean, \Q'\E matches ', \Q\\E matches \, \Q.\E matches . why should " be any different?
09:51	yonatan_	that's how it works in actionscript, and http://java.sun.com/j2se/1.4.2/docs/api/java/util/regex/Pattern.html says that's how it should work in java (although i didn't check if it really does).
09:51	sexpbot	"Pattern (Java 2 Platform SE v1.4.2)"
09:58	yonatan_	although Regular Expressions Cookbok says "If you omit the \E, all characters after the \Q until the end of the regex are treated as literals."
10:03	yonatan_	which implies that the regexp can end without an \E. so no need to fix anything i guess :)
10:07	patrkris	rhickey: what exactly from the Ennals paper convinced you that Clojure's STM should not be obstruction-free? I can't connect the ends.
10:27	_na_ka_na_	hi
10:27	_na_ka_na_	when im doing (defrecord A [i j]) .. it gives a reflection warning ..Reflection warning, NO_SOURCE_PATH:4 - call to contains can't be resolved.
10:28	_na_ka_na_	using the latest snapshot for 1.2
10:28	_na_ka_na_	clojure-1.2.0-master-20100518.110252-71.jar
10:29	_na_ka_na_	is this as expected? or am i doing something wrong?
10:32	_na_ka_na_	helloooo anyone?
10:35	AWizzArd	,(read-string "{:a 1, :b}")
10:35	clojurebot	3
10:35	AWizzArd	:)
10:35	AWizzArd	The Exception is a bit misleading.
10:37	_na_ka_na_	, (defrecord A [i j])
10:37	clojurebot	DENIED
10:37	_na_ka_na_	,(defrecord A [i j])
10:37	clojurebot	DENIED
10:39	Borkdude	,(letfn [foo #("umbrella")] (foo)
10:39	clojurebot	EOF while reading
10:39	_na_ka_na_	,clojure-version
10:39	clojurebot	{:interim true, :major 1, :minor 2, :incremental 0, :qualifier "master"}
10:39	Borkdude	,(letfn [foo #("umbrella")] (foo))
10:39	clojurebot	java.lang.RuntimeException: java.lang.RuntimeException: java.lang.IllegalArgumentException: Don't know how to create ISeq from: clojure.lang.Symbol
10:39	Borkdude	o yeh, never mind
10:48	hoeck	_na_ka_na_: I guess thats a bug, the values method in the defrecord expansion probably needs a typehint
10:50	hoeck	_na_ka_na_: but the defrecord will work regardless of the reflection warning, it just uses reflection to compute .containsValues
10:50	_na_ka_na_	hmm .. even this gives the same warning (defrecord A [^int i ^int j]) .. never mind
10:50	Licenser	Hmm anyone around who used ring and sessions before?
10:51	hoeck	_na_ka_na_: its not related to hinting the records fields
10:51	_na_ka_na_	hoeck: got it .. thx
10:51	cemerick	rhickey: that defrecord/type class change issue is reproducible, but only sporadically, and does appear to be related to the namespace import mechanism. Gotta run for a bit, but I'll bear down on it later.
10:52	AWizzArd	How can I catch read-time exceptions?
10:52	AWizzArd	,(try (read-string "{[]}") (catch Exception e (println "Hi")))
10:52	clojurebot	AWizzArd: Pardon?
10:52	AWizzArd	On my system this throws an Exception and does not enter the catch block.
10:53	gfodor	are there any known issues with anonymous closures leaking? I have been load testing a service written in clojure and after taking a heap dump after a night of testing, there are thousands of what look to be anonymous function closures stuck in RAM
10:53	chouser	AWizzArd: your exception is coming during printing, not during reading.
10:53	chouser	it is read without error, which is a bit startling to be sure.
10:54	AWizzArd	,{[]}
10:54	clojurebot	java.lang.RuntimeException: java.lang.ArrayIndexOutOfBoundsException: 1
10:54	chouser	,(class {[]})
10:54	clojurebot	1
10:54	AWizzArd	chouser: to what does this eval for you? (try {[]} (catch Exception e (println "Hi")))
10:54	chouser	,(class (read-string "{[]}"))
10:54	clojurebot	clojure.lang.PersistentArrayMap
10:54	Licenser	might it be a lazyness problem?
10:55	hoeck	laziness
10:55	Chousuke	I thought that was a know issue?
10:55	chouser	no, it's just that the reader creates a map that can't print itself.
10:55	chouser	not about lazy seqs.
10:55	Chousuke	you get weird behaviour with illegal literals.
10:55	Chousuke	,`{~@[1]}
10:55	clojurebot	1
10:55	Chousuke	,`{~@[1 2]}
10:55	clojurebot	1
10:56	AWizzArd	,(with-out-str (read-string "{[]}"))
10:56	clojurebot	""
10:56	Chousuke	hm, the latter has worked for me before :P
10:57	Licenser	is the ring developper in the channel every now and then? Everyone an idea?
10:59	AWizzArd	So, currently, if I want to check if some expression is valid I will have to do (try (print (read-string s)) (catch Exception e "not valid"))
10:59	cemerick	Licenser: try #compojure?
10:59	Licenser	cemerick: thanks!
10:59	AWizzArd	putting read-string into try does not do the trick, I also have to print it
11:01	AWizzArd	ah okay, this is it then: (try (with-out-str (print (read-string "{[]}"))) (catch ...))
11:02	Licenser	http://grab.by/4rce it worked!
11:05	tcrayford	chouser: ended up giving up on the whole compiler/analyze thing, it wasn't that useful in the end
11:07	Licenser	tcrayford: did you look in the analyzing methods the sandbox provides? they can be 'abused' for quite some funny things
11:08	tcrayford	Licenser: not yet
11:08	Licenser	nods
11:08	tcrayford	I found that repetition is almost better done without looking at just the variables in each specific function
11:08	tcrayford	and more looking at the length/layout of sexps
11:08	Licenser	nods
11:09	tcrayford	it points out things that should obviously be functions/macros pretty well now that I've made that change
11:11	tcrayford	the next thing to do: code generation for proxy (ala cmerick's article)
11:12	tcrayford	Licenser: is there a type in the docstring for add-reader-to-sandbox? I've never seen the word 'conuse' before
11:12	tcrayford	*typo
11:12	Licenser	tcrayford: I've never seen it before either :P
11:13	tcrayford	:)
11:20	AWizzArd	What is a meaningful Exception for wrong entries in a config file?
11:23	MrHus	Hi I came across The Clojure Library Coding Standards, and saw the following rule:
11:23	MrHus	Unroll optional named arguments. Callers should not have to wrap optional named arguments in a map literal:
11:24	MrHus	But how do you get the [& args] in a map
11:24	MrHus	An example from the page: (release-sharks 2 :laser-beams true) ; good (release-sharks 2 {:laser-beams true}) ; bad
11:26	Licenser	question: I have this code:
11:26	Licenser	(. clojure.lang.LockingTransaction (clojure.core/runInTransaction (clojure.core/fn [] (alte r y inc)))) (it is a dosync)
11:26	Chousuke	MrHus: on 1.1, (apply hash-map args)
11:26	Licenser	what is happening here? clojure.lang.LockingTransaction is a class, but there seems to be no function called o.O
11:26	hoeck	MrHus: (defn foo [n & {:keys [laser-beams, other-key]})
11:26	Chousuke	MrHus: and 1.2 has a new destructuring syntax, so you can do ... that.
11:26	Licenser	is it the same as new?
11:27	Chousuke	Licenser: note the . special form
11:27	AWizzArd	,(Exception. "hi")
11:27	clojurebot	#<Exception java.lang.Exception: hi>
11:27	Chousuke	it
11:27	AWizzArd	,(throw (Exception. "hi"))
11:27	Licenser	Chousuke: yap
11:27	clojurebot	java.lang.Exception: hi
11:28	AWizzArd	,(throw (proxy [Throwable] [] (getMessage [] "hi")))
11:28	clojurebot	java.lang.IllegalStateException: Var null/null is unbound.
11:28	AWizzArd	hiredman: uh oh
11:28	Chousuke	it's calling the runInTransaction method of the LockingTransaction class.
11:28	Licenser	The question is the . special form takes a class a member and parameters right? but I don't see a member or parameters in this call
11:28	Chousuke	it works for static methods too.
11:28	Licenser	but why the () there?
11:29	Chousuke	the static method takes parameters :)
11:29	Chousuke	(. class (staticmethod args))
11:29	Chousuke	(. obj (instancemethod args))
11:29	Licenser	oh I thought it was like (. class method args)
11:29	Licenser	darn it ^^
11:29	AWizzArd	Anyway: is there a name to give my proxied Throwable a custom name? Something different from #<Throwable$0 my.companies.ns.proxy$java.lang.Throwable$0>?
11:30	Licenser	Chousuke: thanks for the update :) I'll work this out!
11:30	Chousuke	AWizzArd: not the class.
11:30	AWizzArd	,(proxy [Throwable] [])
11:30	clojurebot	java.lang.IllegalStateException: Var null/null is unbound.
11:30	AWizzArd	Chousuke: ok
11:32	Chousuke	Licenser: note that the syntax means that if you want to call a method on an instance of Class, you need to do eg. (. (identity String) newInstance) :)
11:32	Chousuke	Licenser: but this is usually not a problem
11:32	MrHus	Chousuke so you can't destructure the argument in a map in 1.1?
11:32	Chousuke	MrHus: correct. it's a new feature.
11:33	Licenser	Chousuke: it is for clj-sandbox to allow dosync ;)
11:33	Chousuke	Licenser: usually the difference is determined from the sugared form
11:33	joshua-choi	Question: when protocols were first introduced (http://www.assembla.com/wiki/show/clojure/Protocols), I got the impression that you named them "ASomething" by convention. Is this really true though?
11:33	sexpbot	"Show \| Clojure \| Assembla"
11:33	Chousuke	ie. (.foo bar) is always an instance method call
11:33	Chousuke	joshua-choi: nah.
11:34	joshua-choi	Eh.
11:34	Chousuke	joshua-choi: I think the convention is just to call them Something :P
11:34	Chousuke	joshua-choi: though that might change.
11:34	MrHus	Chousuke What's the syntax in 1.2?
11:34	Chousuke	joshua-choi: PSomething is not a bad choice either.
11:34	joshua-choi	Chousuke: Oh oh. Well, I'll get rid of my "A"s.
11:35	joshua-choi	What's up with APersistentList, etc., though
11:35	Chousuke	MrHus: just map destructuring after the &, borrowing hoeck's example (defn foo [n & {:keys [laser-beams, other-key]})
11:36	Chousuke	joshua-choi: they're abstract base classes
11:36	joshua-choi	Ah
11:36	joshua-choi	Better not conflate protocols with them then
11:36	joshua-choi	Nomenclature-wise
11:36	Chousuke	yeah.
11:40	hamza	guys how can i access a filed in a proxy? such as extended class has a filed called someObject and i need to invoke a function on this object?
11:41	hamza	* field
11:42	Chousuke	'this is bound to the proxy instance within its methods
11:44	hamza	Chousuke: (.someObject 'this) is this the correct usage?
11:44	Chousuke	no, that would be calling the method on the symbol :P
11:44	Chousuke	lose the quote :)
11:45	AWizzArd	Better test than (or (true? b) (false? b))
11:45	hamza	kk, thanks alot.
11:46	AWizzArd	ah (instance? Boolean b)
11:46	Chousuke	heh, that is indeed a confusing test :P
12:04	rsenior	lpetit: thanks for the blog comment, do you have some info on the -?> operator you mentioned? I couldn't find it in the docs...
12:06	lpetit	look in clojure.contrib.core
12:06	lpetit	,(doc -?>)
12:06	clojurebot	"clojure.contrib.core/-?>;[[x form] [x form & forms]]; Same as clojure.core/-> but returns nil as soon as the threaded value is nil itself (thus short-circuiting any pending computation). Examples : (-?> \"foo\" .toUpperCase (.substring 1)) returns \"OO\" (-?> nil .toUpperCase (.substring 1)) returns nil "
12:06	lpetit	rsenior: ^^^
12:07	rsenior	lpetit: ah, in contrib, thanks
12:08	lpetit	rsenior: I know the -?> operator quite well (wrote it, my only contribution AFAIK :) )
12:09	lpetit	must leave, cu
12:09	rsenior	lpetit: does just what I need, I also didn't know that -> works on java methods, I thought it was just for clojure functions
12:10	lpetit	rsenior: np, clojure changes are not always well propagated, and the most stuff I know has been gathered on the ml and this channel
12:10	lpetit	(I mean, once I had read the clojure.org site from a to z, of course)
12:20	arkahn	do the macros #^ and ^ have anything to do with each other, or is #^ still current and ^ just being deprecated and forgotten?
12:21	chouser	in git master, #^ and ^ mean the same
12:22	arkahn	chouser: is that 1.2/1.3?
12:23	arkahn	chouser: 1.1 gives deprecation warnings on ^
12:25	hamza	is not permitted to access protected objects in a class? when i do (.someObject (proxyed-class)) gives field not found exception..
12:25	chouser	arkahn: right, in 1.1 ^foo expanded to (meta foo), with deprecation warning.
12:26	chouser	in 1.2 ^ will mean the same as #^
12:26	arkahn	chouser: thank you
12:27	arkahn	and I think google needs to learn how to search on things like #^ ; )
13:10	LauJensen	http://dorophone.blogspot.com/2008/03/common-lisp-reader-macros-simple.html
13:10	sexpbot	"Dorophone: Common Lisp Reader Macros: A Simple Introduction"
13:10	LauJensen	:)~
13:13	KirinDave	Reader macros are beautiful
13:13	KirinDave	I miss them badly
13:16	etate	LauJensen: your new blog is awesome man... this is the best use of clojure on the web i've seen so far - very professional
13:16	etate	LauJensen: congrats
13:16	LauJensen	etate: wow, thanks man :)
13:16	KirinDave	LauJensen: url plz?
13:16	LauJensen	btw, Ive been looking for you, where's that bright theme? :)
13:16	technomancy	I was wondering how long it would take before the ".php" in the URL would be too much for Lau to take. =)
13:16	LauJensen	KirinDave: http://www.bestinclass.dk/blog.html
13:16	sexpbot	"Best In Class - Software Innovator"
13:16	LauJensen	technomancy: yea, it was killing me :)
13:17	KirinDave	LauJensen: So this is in clojure?
13:17	LauJensen	yep
13:17	etate	LauJensen: :) Im in process of changing it i'll paste it a bit later for you
13:17	KirinDave	Fun
13:17	KirinDave	Is it on GAE?
13:17	LauJensen	Nope, just a Linux/NGINX combo
13:18	LauJensen	etate: great, and if Im not here feel very free to send me an email :)
13:18	etate	LauJensen: will do, I really love your new logo
13:18	LauJensen	etate: Im very glad - though its about to get tweaked a little
13:19	LauJensen	(I think)
13:19	LauJensen	Im not sure I can ever be happy with a website that doesn't have the Knight Rider scroller and theme song in flash
13:19	etate	LauJensen: yeah it could use some polish for some of the UI elements but the direction is great, I mean it looks great as it is - and its a good example of how clojure can compete in this domain
13:20	LauJensen	Yea, I hope you guys can verify that the site as a whole is much more responsive now, even in peak periods
13:21	etate	LauJensen: yeah, that was a noticeable difference
13:21	LauJensen	great; I gotta duck out. etate you got my email right?
13:21	Borkdude	etate: LauJensen: agreed about the competition. I just discussed functional programming today with a colleague, that we should promote it at our work, but he said, it's still just an academic thing (he is into Haskell). So I explained him that serious nice things happen these days in Clojure, people translate their blogs into it ;)
13:21	LauJensen	hehe
13:21	etate	LauJensen: Its on your site right? :) So cool that you included enlive tips in your post too :)
13:22	LauJensen	etate: yea it is. And more Enlive tips to come when I realise the code
13:22	LauJensen	Anyway - I gotta duck out
13:22	KirinDave	I went all the way down the rabbit hole of compiling enlive transforms on templates into actual functions before I realized it couldn't work.
13:22	KirinDave	I was pretty bummed out with that.
13:22	Borkdude	LauJensen: bye
13:23	etate	KirinDave: why couldn't it work?
13:23	KirinDave	etate: Because inserting new markup would require a rescan of the whole tree.
13:23	KirinDave	If you are a good boy and your selectors don't overlap in any way, it's MUCH faster.
13:23	KirinDave	Otherwise it reduces to the same thing
13:24	etate	KirinDave: can you not memoize or something? (naive suggestion warning)
13:24	KirinDave	etate: Imagine two xforms on a tree
13:25	KirinDave	One inserts a series of <article> tags.
13:25	KirinDave	The other decorates article tags.
13:25	KirinDave	If the information for generating those article tags is dynamic, it's very difficult to fold the two together.
13:27	etate	KirinDave: so what are you using as an alternative to this?
13:27	etate	or what did you decide on doing in the end :)
13:32	cgrand	KirinDave: can't you decorate the articles as you insert them?
13:36	KirinDave	cgrand: I dunno what that'd be like
13:37	etate	cgrand: by the looks of it this was LauJensens approach in his blog, "baking" the post into html
13:37	KirinDave	cgrand: I just am bummed because I wrote a bunch of code without thinking about it. ;)
13:37	etate	KirinDave: check http://www.bestinclass.dk/index.clj/2010/05/refresh-your-cache--best-in-class-has-been-baked.html
13:37	sexpbot	"Best In Class: Refresh your cache - Best In Class has been baked"
13:38	KirinDave	cgrand: It's possible that for a limited class of selectors I could make it work
13:38	KirinDave	cgrand: But if people get exotic about the boundaries of things, it'd be difficult to get a correct result.
13:42	cgrand	I'm not sure to understand what you want: did you want a sort of pipeline (-> html-tree xform1 xform2 render)?
13:43	cgrand	I see you are speaking about non-overlapping selectors, in enlive you can now specify sets of indepedent transforms, thus they are applied in one pass
13:43	KirinDave	cgrand: I tried to take the template and the xforms and precompile it into a function that just patches wholes in the template.
13:43	KirinDave	cgrand: Basically xform to a ` macro.
13:43	KirinDave	cgrand: I was trying to get enlive generated pages to exceed 2k r/s
13:44	KirinDave	And it works, but not if the selectors overlap.
13:44	KirinDave	At least not yet
13:45	cgrand	very interesting, are your experiments public?
13:45	KirinDave	cgrand: Sadly, no. It's a microsoft deal.
13:45	KirinDave	But I will recreate at home once I am out from under their cruel yolk
13:45	KirinDave	cgrand: Some common lisp systems do it this way tho.
13:45	technomancy	KirinDave: how much longer?
13:45	KirinDave	technomancy: Sept 1 unless I get a good offer.
13:46	technomancy	nice
13:46	KirinDave	technomancy: A mutual acquaintance of ours has expressed interest in pulling me away. I'm considering it strongly
14:18	ArkRost	Hi! I find a strange thing: ('a 1 2) return 2. Why does it happens?
14:19	chouser	ArkRost: symbols used as functions expect their first arg to be a map, and look themselves up in it.
14:19	chouser	('a {'c 1, 'b 2, 'a 3})
14:19	chouser	,('a {'c 1, 'b 2, 'a 3})
14:19	clojurebot	3
14:20	chouser	they accept a second arg which is returned if the key is not found
14:20	chouser	,('z {'c 1, 'b 2, 'a 3} :missing)
14:20	clojurebot	:missing
14:20	chouser	that second arg is also returned if the first arg isn't a map
14:20	chouser	,('z 1 :missing)
14:20	clojurebot	:missing
14:20	chouser	,('z 1 2)
14:20	clojurebot	2
14:20	chouser	,('a 1 2)
14:20	clojurebot	2
14:22	ArkRost	ok. Another question: how can I shadow special forms(def, do and ect)?
14:22	technomancy	ArkRost: if you have to ask ... you should probably think twice before doing it. =)
14:23	technomancy	there's probably a better way to do what you're thinking of
14:23	technomancy	sorry to sound like a smartass
14:24	chouser	I actually think it may be impossible
14:24	ArkRost	oh no.. I don't want to use it in code. Just curious
14:24	chouser	,(let [def 5] def)
14:24	clojurebot	DENIED
14:24	chouser	bah
14:24	chouser	,(let [do 5] (do do))
14:24	clojurebot	5
14:25	chouser	,(let [do (fn [] 7)] (do))
14:25	clojurebot	nil
14:25	chouser	yeah, don't do it. Even if it's possible in some cases, such as above, I very much doubt it's supported and could quit working at any time.
14:26	ArkRost	ok. Thanks
14:27	Borkdude	('fibnext 0 1)
14:27	Borkdude	,('fibnext 0 1)
14:27	clojurebot	1
14:27	Borkdude	damn it works! ;)
14:28	Borkdude	('add 0 1)
14:28	Borkdude	,('add 0 1)
14:28	clojurebot	1
14:28	Borkdude	yup perfect.
14:30	Borkdude	what is so graceful about symbols accepting everything, instead of throwing actually?
14:31	lancepantz	Borkdude: i like the behavior, but the powers have be said not to rely on it and they may change it at any point in time
14:31	lancepantz	*that be
14:31	chouser	what? symbols as functions are fully supported, afaik.
14:31	chouser	just like keywords
14:31	lancepantz	i thought he was referring to the alphanumeric requirement
14:32	chouser	oh
14:32	lancepantz	i may have misunderstood
14:32	Borkdude	chouser: I mean, you gave the example of the MapKey throwing an exception instead of nil
14:32	Borkdude	why is returning nil better, errors may be hard to find
14:32	lancepantz	yep
14:33	Borkdude	and the same goes for ('foo 'dont-care-what-is-here 'i-just-return-this)
14:34	Borkdude	,('foo 'dont-care-what-is-here 'i-just-return-this)
14:34	clojurebot	i-just-return-this
14:34	chouser	If any sort of reasonable default behavior can be provided, I genearlly prefer that over exceptions.
14:35	chouser	leads to cleaner simpler code, rather than try/catches and if's all over the place.
14:35	Borkdude	so exceptions aren't considered helpful in Clojure?
14:36	Chousuke	I'd say they're a last resort thing
14:36	chouser	I'm not setting clojure policy here, just voicing my agreement with some specific decisions.
14:36	Chousuke	when something is obviously wrong
14:36	technomancy	Chousuke: dare we say ... exceptional?
14:36	Chousuke	technomancy: perhaps.
14:37	Chousuke	technomancy: though what qualifies as exceptional is open to discussion
14:37	chouser	if there is a reasonable and/or obvious default, why not provide that instead of forcing the code to be explicit.
14:37	chouser	(meta nil) could throw, but I'm happy it just returns nil
14:37	Borkdude	I would say an empty map is ok, but when would it be good to give a non-map to a symbol?
14:37	Chousuke	Borkdude: maybe you have some generic lookup code
14:38	Chousuke	Borkdude: that could take any collection and just return nil if the item is not there
14:38	Chousuke	or if it's not a collection
14:38	Chousuke	so you can do stuff like (if ('something foo) (dostuff) (fail))
14:39	Chousuke	or just (dostuff ('something foo 'default))
14:40	chouser	hey look, you eliminated an 'if'! congrats!
14:40	Borkdude	I guess you can always check yourself if a map has been provided, if it's really important to you
14:41	Chousuke	if you want an exception you can always do the lookup as (foo 'something) :(
14:41	Chousuke	:) I mean :P
14:41	Borkdude	,({:a "dude"} :b)
14:41	clojurebot	nil
14:41	Borkdude	?
14:41	chouser	,(nil :b)
14:41	clojurebot	java.lang.IllegalArgumentException: Can't call nil
14:42	chouser	,(1 :b)
14:42	clojurebot	java.lang.ClassCastException: java.lang.Integer cannot be cast to clojure.lang.IFn
14:42	Borkdude	ah ok
14:43	Borkdude	I guess there are always ways to get what you want out of Clojure ;)
14:44	Borkdude	,nil
14:44	clojurebot	DENIED
15:02	LauJensen	etate: progress? :)
15:02	arohner	is there any way to specify the startup arguments to the JVM using lein / maven?
15:02	arohner	or any other tool? I dislike writing my clojure startup script in bash, because that's the only way I know of right now
15:03	tcrayford	lein is just a bash script
15:03	tcrayford	so if you want to, you could copy the lein bash script to your project, then modify it
15:04	arohner	tcrayford: I would like to define my startup script in something lein-y, that would go in the project.clj
15:04	tcrayford	arohner: there's no decent way to do that now (as far as I know)
15:04	tcrayford	the jvm has to start before lein can process project.clj
15:05	arohner	hrm, looks like maven exec might do it
15:06	LauJensen	chouser: when do we get reader macros in clojure?
15:06	chouser	LauJensen: never
15:06	Raynes	Ever ever.
15:07	chouser	LauJensen: of course you can write your own reader and/or fork clojure, but don't expect many people to use your new language. :-)
15:08	LauJensen	chouser: Why not ?
15:08	arohner	LauJensen: reader macros don't compose
15:09	etate	LauJensen: almost there :)
15:10	LauJensen	etate: cool
15:10	LauJensen	arohner: But I just dont see us ever accomplishing the goal of being Lisp-Perl without them :(
15:10	arohner	that's a goal?
15:11	LauJensen	Im kidding of course
15:11	chouser	because you'll have to convince each potential clojure user to trust your judgement over rhickey's. tough.
15:11	kotarak	Isn't @#^foo perly enough?
15:12	LauJensen	chouser: so... no real arguments, its just a matter of taste?
15:12	chouser	what? how'd you get that?
15:13	LauJensen	chouser: I just didn't see a real argument. Reader macros doesn't imply a transfer of trust anymore than regular macros and they can be used in some restricted sense
15:13	kotarak	LauJensen: this was discussed several times, with lots of reasoning in all directions. Check the group archives.
15:14	chouser	I wasn't arguing about reader macros, it's just the challenge that any functionality-fork of clojure would face. You failed to convince rhickey or you wouldn't have forked.
15:14	LauJensen	oh, I wouldn't fork :)
15:14	chouser	ah
15:14	LauJensen	I was just thinking of implementing them in Clojure
15:14	LauJensen	But I'll take kotaraks advice and check the group
15:15	chouser	I think the composability of reader macros is actually a red herring. I mean it's part of the problem, but I actually proposed a feature that would address a subset of reasons people want reader macros that was fully namespaceable, and rhickey smiled politely and said "I don't like it".
15:16	LauJensen	Well, at least he was polite :)
15:16	chouser	they are very rarely necessary and carry a burden for anyone trying to parse or read a clojure file.
15:16	LauJensen	But ok, I guess in all honesty I do actually get along very well without them
15:17	chouser	right now, untrusted clojure can be read. with reader macros this would be impossible
15:17	chouser	untrusted clojure code
15:17	LauJensen	depending a little on how you implement them
15:17	chouser	that is a clojure reader doesn't need to be able to eval -- this has benefits for editors, syntax highlighter, code analyzers, etc.
15:18	chouser	reade macros by definition eliminate all that.
15:18	chouser	and to what benefit? I have a DSL here that needs to support x.y.z field-lookup syntax, with non-standard rules for the resolution of x.
15:18	LauJensen	strong point
15:19	chouser	wrap it in a (--> x.y.z) or something, and a regular macro does just fine.
15:19	etate	LauJensen: http://paste.lisp.org/display/99418
15:19	LauJensen	chouser: , the thing is, I really want 5**2 instead of (Math/pow 5 2) :)
15:19	etate	LauJensen: thats a rough draft of what i'm working on - trying to get rid of the purple
15:19	Chousuke	I think a reader library might be useful though
15:19	chouser	LauJensen: no you really don't.
15:19	etate	LauJensen: I have to head out so i'll send you an updated version some other time :)
15:19	chouser	though apparently Incanter provides that now.
15:20	Chousuke	so people can write their own readers when they need to :)
15:20	kotarak	LauJensen: (def ** #(Math/pow %1 %2))
15:20	LauJensen	cool, thanks etata
15:20	chouser	well, provides 5 ** 2
15:20	LauJensen	chouser: I dont ?
15:21	chouser	rhickey worked so hard to talk us out of including an infix example in the book, and then Leibke goes and puts one in his hugely popular library.
15:21	Borkdude	hehe
15:21	tcrayford	chouser: what did rhickey argue against infix stuff with?
15:21	Chousuke	well, in their defense it does more than just infix math
15:21	Chousuke	and it is a math library :P
15:22	chouser	tcrayford: he was afraid people would actually use it, which was never our point.
15:22	Chousuke	you can just think of it as a dsl for matrix/vector (oh, and scalar) manipulation
15:22	tcrayford	chouser: makes sense
15:23	chouser	our point was to show that clojure could do infix just fine -- the reason it doesn't is because it's undesriable (in clojure) not because it's impossible.
15:23	tcrayford	and demonstrating macros as well
15:24	chouser	I don't think it was a macro. Just a function.
15:24	tcrayford	nice then
15:24	Chousuke	I don't think most people will suffer incanter as a dependency just to get infix math
15:25	chouser	no, but lots of people use incanter. I'm sure I'll end up debugging somebody's infix math code at some point now.
15:25	Chousuke	and I think most math in clojure consists of (apply + ...) or somesuch
15:26	Borkdude	(import-static java.lang.Math pow pow), is this considered normal practice in Clojure?
15:26	Chousuke	Borkdude: you should just use Math/pow I think
15:26	kotarak	no, at least on on my side
15:26	Chousuke	it's not that much longer, is it? :P
15:31	cemerick	arohner: not sure if you've settled anywhere, but look @ clojure-maven-plugin
15:33	arohner	cemerick: interesting. The primary thing I'm looking for is setting JAVA_ARGS
15:35	cemerick	arohner: Sure. That's done via the clojureOptions in the plugin config. i.e. <clojureOptions>-Xmx512m -Djava.awt.headless=true -XX:MaxPermSize=256m</clojureOptions>
15:36	lancepantz	i don't know what to search for, so i'll just ask- how do i jump to the closing parent for one my cursor is in in emacs?
15:36	lancepantz	like % in vim
15:36	tcrayford	I've never found something that works well for that in vanilla emacs
15:36	arohner	lancepantz: C-M-f, if you're running paredit
15:36	lancepantz	s/parent/paren
15:36	arohner	cemerick: cool, thanks
15:36	lancepantz	that works, thanks arohner
15:37	tcrayford	lancepantz: note that works for going forwards
15:37	tcrayford	you need C-M-b for backwards
15:37	lancepantz	just realized that :)
15:37	lancepantz	thansk
15:45	joshua-choi	uestion. I used to do (isa? (type obj) t) whenever I was checking if an object was a certain type. With the advent of records, should I use (= (class obj) t) instead, if I'm not using a protocol?
15:46	Chousuke	you can use instance?
15:46	Chousuke	though I think checking for an interface is better.
15:46	Chousuke	the class can freely change then
15:47	joshua-choi	I'm not using a protocol or interface; there's only one type of record to check for. But I suppose that whenever I need to check a type, I should consider using a protocol instead...
15:48	Chousuke	perhaps.
15:48	joshua-choi	I totally didn't know about instance?, though
15:48	Chousuke	a protocol function should be interchangeable with a normal function in the best case.
15:48	Borkdude	chouser: does TjOC treat defrecord, protocol and the like somewhere?
15:49	chouser	Borkdude: ch8, not released yet
15:49	Chousuke	so if protocols don't work for you, you can replace it with a normal function with an instance check.
15:49	chouser	it was mostly done before defrecord was invented, so we need to revise...
15:49	joshua-choi	Chousuke: When would you want to do that?
15:49	Borkdude	chouser: ah good to know that will come up
15:50	Chousuke	joshua-choi: dunno. I suppose replacing a protocol function with a multimethod is more plausible
15:50	Borkdude	chouser: is middleware also a topic that belongs in there, or is that a compjore specific thing?
15:50	Chousuke	joshua-choi: but the point remains that they're all just functions
15:51	joshua-choi	Does anyone use (type ...) nowadays?
15:51	chouser	Borkdude: we won't be dealing with specific library features like that.
15:51	chouser	we're way over our target pagecount already
15:51	Borkdude	chouser: I just wondered if that term was a general thing in Clojure
15:52	chouser	Borkdude: it's not
15:52	kotarak	joshua-choi: yes, why not?
15:52	Borkdude	k
15:52	joshua-choi	kotarak: (type obj) is (or (:type (meta obj)) (class obj)). I'm wondering if using :type in metadata is still idiomatic at all
15:53	joshua-choi	I myself use it, but I'm wondering if I should change it...
15:53	joshua-choi	Same goes for isa? in the context of object type hierarchies
15:54	kotarak	btw, what do I use to test for a deftype? Is its type still ::SomeType? Or do I test for a class?
15:55	AWizzArd	kotarak: (type yourRecord) ==> ou
15:55	AWizzArd	kotarak: (type yourRecord) ==> your.ns.recordName
15:55	kotarak	AWizzArd: so I test with (instance? your.ns.recordName x)?
15:55	AWizzArd	exactly
15:56	AWizzArd	if you use Protocolls this test will be done automatically for you
15:56	kotarak	AWizzArd: Except when I don't use a protocol function and want to test for the type explicitely.
15:56	AWizzArd	positive
15:59	_na_ka_na_	hi , i want to create a doubly linked list .. a node looks like (defstruct node :data :next :prev) .. so first i cr8 a list of nodes and then try to link them up .. is there a way to do it w/o creating each node as an atom/ref .. i ask coz after i create the list i'm not going to mutate it ..
15:59	_na_ka_na_	whats the most idiomatic clojure way to do this
15:59	chouser	_na_ka_na_: why do you want a doubly linked list?
16:00	Chousuke	I don't think there is a way to do that with immutable thigns
16:00	_na_ka_na_	i actually want to create a graph data structure .. where nodes are connected to other nodes via 2-3 different kinds of edges ...
16:01	_na_ka_na_	i thot ask abt doubly linked list would be easier
16:01	Chousuke	maybe you should use a set or a map of edges then
16:01	_na_ka_na_	hmm ya thats an option ..
16:01	Chousuke	for doubly linked lists you'd need mutual references, which are impossible with persistent things.
16:02	_na_ka_na_	so i create a list of nodes + a map of sets (key=node, value=set of connected edges) ?
16:02	_na_ka_na_	oh i meant set of connected nodes
16:03	Chousuke	something like that I guess.
16:03	chouser	a common solution is a map of ids to nodes, with each node refering to its neighbors by id
16:04	_na_ka_na_	hmm .. that looks good ..
16:05	_na_ka_na_	but .. how do these two solutions compare .. i mean where i have nodes as atoms v/s persistent maps ..
16:05	_na_ka_na_	the first one makes a more intuitive picture in my head ..
16:06	_na_ka_na_	is the only concern perf?
16:06	alexyk	which predicate do you give to every? to check none of a seq's elements is nil?
16:07	_na_ka_na_	(comp not nil?)
16:07	alexyk	shorter!
16:07	chouser	(not (some nil? ...))
16:07	Borkdude	(complement nil?) ?
16:08	Chousuke	identity
16:08	chouser	(every? identity ...)
16:08	Chousuke	fails on false though.
16:08	chouser	is the seq produced by 'map' perchance?
16:08	alexyk	hmm... let's call it meaty?
16:08	alexyk	every? meaty?
16:09	alexyk	but it should be in core! not-nil?
16:09	alexyk	not= is there
16:09	alexyk	some useless when-not is there!
16:09	alexyk	almost-useless
16:09	ninjudd	when-not isn't useless
16:09	lancepantz	ruh roh
16:09	alexyk	ninjudd: it was an overstatement :)
16:10	Borkdude	isn't there a macro that can define the complement each thing in core and append -not to it's name ;)
16:10	chouser	alexyk: you need to differentiate between nil and false?
16:10	alexyk	hope not, but am afraid
16:11	alexyk	I'll defn ismeat? as not nil?
16:11	alexyk	is? <-- cute
16:11	alexyk	every? is?
16:11	_na_ka_na_	is what?
16:11	alexyk	exists?
16:11	Borkdude	nil exists
16:12	alexyk	it is
16:12	alexyk	Borkdude: but things which are nil don't
16:12	_na_ka_na_	but how to ppl looking at your code understand is ..?
16:12	Borkdude	yes, they do, because they ARE nil
16:13	alexyk	does a key exist in a map if lookup is nil?
16:13	Borkdude	does the lookup return the key?
16:14	alexyk	does a value for the key exist?
16:14	Borkdude	it's a default value for non-mapped keys
16:14	tcrayford	,({:a nil} :a)
16:14	clojurebot	nil
16:15	_na_ka_na_	better to use contains
16:15	_na_ka_na_	,(contains? {:a nil} :a)
16:15	clojurebot	true
16:15	Borkdude	I think not nil? is the best description you can get ;)
16:15	tcrayford	alexyk: you want "untruthy"
16:16	tcrayford	or perhaps not-truthy?
16:16	alexyk	Borkdude: alas
16:17	_na_ka_na_	i use not nil quite often so i've just put (defn not-nil? (comp not nil?)) at the top ..
16:17	remleduff	vici?
16:19	_na_ka_na_	hey guys how abt the graph ds .. how do the atoms v/s maps solution compare ..
16:21	chouser	_na_ka_na_: don't use atoms for this
16:22	_na_ka_na_	chouser but why? .. just want to understand ..
16:22	chouser	it's not about performance -- I'm not sure which would be faster, actually.
16:23	alexyk	how do you assert something is a number?
16:23	_na_ka_na_	why does your gut feeling say no to atoms? :)
16:23	chouser	rather it's sort of an abuse of an atom to have it sitting there able to change with a vague promise that you won't.
16:23	_na_ka_na_	hmm ya ..
16:24	chouser	if you can do something more like transients, where you can "lock it" when you're done building it, that would be something else.
16:24	Borkdude	,(number? "foo")
16:24	clojurebot	false
16:24	Chousuke	_na_ka_na_: it would be just emulating traditional mutability, which is not maintainable :/
16:24	Borkdude	,(assert (number? "foo"))
16:24	clojurebot	java.lang.AssertionError: Assert failed: (number? "foo")
16:25	Chousuke	you don't want your core data structure to have anything to do with state :P
16:25	alexyk	Borkdude: thx! that's my not-nil :)
16:25	_na_ka_na_	Chousuke: i think every one agrees on that .. thats why we are here :D ..
16:26	Borkdude	alexyk: =)
16:28	_na_ka_na_	but that is an issue only if someone actually changes the ds after building it .. if this graph of mine is a "private" ds which i don't expose in my API .. and i know that i'll never mutate it ..
16:28	tcrayford	well if you're never going to mutate it, why do you need an atom?
16:29	_na_ka_na_	its not like i favor the atoms .. i'm just trying to put arguments both ways
16:29	Chousuke	_na_ka_na_: in this case, there isn't much of a case to be made in favour of the atoms :)
16:30	Chousuke	people will think it's unidiomatic, ugly and stupid :P
16:30	_na_ka_na_	the graph data structure represented with atoms is more intuitive no? .. anyone who sees it will understand at the first glance?
16:30	Chousuke	even if it works.
16:30	chouser	is the graph a value or not? if it's a value in the way other complex nested map/vector things are, then you get all the same benefits: keep old version, build using 'reduce', etc.
16:30	_na_ka_na_	hehe ya thats one more point against :)
16:30	Chousuke	_na_ka_na_: no, a person used to clojure will go "what?"
16:30	chouser	but as soon as there's an atom in there, it's a stateful thing and you can have only the one.
16:31	chouser	gotta go
16:31	Chousuke	_na_ka_na_: while they might understand mutability, atoms are meant to address mutability in a very different way from what you're suggesting, so they would be confused.
16:32	_na_ka_na_	yes I agree with that point .. its not idiomatic Clojure at all ..
16:32	Chousuke	actually, s/mutability/state/g
16:34	Chousuke	doing things "the right way" might be difficult at first but this gets easier with experience.
16:34	Chousuke	and it's never too early to start experiencing :P
16:34	_na_ka_na_	now that seems like the best argument to me :P ..
16:35	Borkdude	atoms are there, but never use them!
16:35	Borkdude	heh ;)
16:35	_na_ka_na_	hehe ..
16:36	Chousuke	try the approach using maps of ids -> node where node = some stuff + set of edges which are pairs of [edge-type, node-id] (you had several kinds of edges, right?)
16:36	Chousuke	also, starting advice: don't be tempted to use struct maps
16:37	Chousuke	they're not real types, and you won't need them until you know you need them :P
16:37	_na_ka_na_	ya i have several kinds of edges ...
16:38	_na_ka_na_	ya if im not using atoms .. then no need of structmap i guess ..
16:38	Chousuke	struct maps are just an optimisation of regular maps
16:38	Borkdude	What would be a good example of import-static?
16:38	_na_ka_na_	Math/PI ?
16:39	Chousuke	if you feel you need the memory benefit, it should be pretty easy to convert code using plain maps to struct maps
16:39	tcrayford	struct-maps are confusing when you're starting out. The first major thing I wrote in clojure used struct maps, and I look back on it now with annoyance
16:39	tcrayford	they look so like classes :/
16:39	technomancy	struct-maps are a tank trap
16:39	Chousuke	tcrayford: yeah, I think the first reaction from people new to clojure must be something like "ooh, structs, I know those"
16:40	_na_ka_na_	but I just treat them as regular maps ..? only its named and little more optimized
16:40	Chousuke	then they go and use struct maps. no real harm there, but it's often unnecessary ceremony.
16:40	tcrayford	technomancy: looking at the swank-clojure source, it says M-TAB to complete symbol, wheras slime says C-c TAB
16:40	AWizzArd	Isn’t completion on just <Tab> only?
16:40	technomancy	tcrayford: they both work, but in most WMs C-c TAB is easier to invoke.
16:40	tcrayford	s/source/README
16:40	technomancy	I'll change the readme; thanks.
16:41	Chousuke	_na_ka_na_: the optimisation won't matter unless you have many "instances" of the base map (in the order of several thousand)
16:41	tcrayford	AWizzArd: that's slime specific completion
16:41	AWizzArd	tcrayford: which one? With tab or C-c Tab?
16:41	tcrayford	C-c TAB
16:41	_na_ka_na_	Chousuke: I have around 100,000 nodes .. so isn't struct-map better
16:41	technomancy	AWizzArd: bare tab is usually bound to indentation
16:41	technomancy	unless you're in the repl
16:41	AWizzArd	technomancy: yes, in the repl i mean
16:41	Chousuke	nathanmarz: will your node be a map?
16:41	tcrayford	or using smart-tab-mode or summat
16:41	Chousuke	oops
16:41	AWizzArd	indentation and completion
16:42	tcrayford	does bare tab work in the repl for completion?
16:42	Chousuke	_na_ka_na_: couldn't the node be just a pair?
16:42	Chousuke	nathanmarz: no keys, just [stuff, set-of-edges]
16:42	AWizzArd	M-Tab would not be so nice for Windows users - it switches out of Emacs to the next application.
16:42	tcrayford	same for osx :/
16:43	AWizzArd	I put fuzzy-completion on C-Tab
16:43	Borkdude	technomancy: maybe a dumb question, but why would I upgrade to swank-clojure 1.2?
16:43	technomancy	Borkdude: all the cool kids are doing it.
16:43	Chousuke	nathanmarz: I suppose a struct-map could be useful too
16:43	Borkdude	technomancy: I noticed, that's why I ask ;)
16:43	technomancy	Borkdude: here's the list of new features: http://github.com/technomancy/swank-clojure/blob/master/NEWS
16:43	AWizzArd	technomancy: btw, is the freshest swank-clojure + clojure-mode working with the freshest slime?
16:44	Borkdude	technomancy: tnx
16:44	technomancy	Borkdude: who-calls and swank-break are pretty awesome
16:44	Chousuke	nathanmarz: just don't think it's anything more than a regular map; that's a common mistake.
16:44	_na_ka_na_	Chousuke: yup .. it can be for the moment.. but later i'll need to introduce several kinds of attributes with the nodes (like {:id :data :attr1 :attr2 ..}) .. i could use several maps for this .. one for data, one for attr1 .. but isn't that overkill ?
16:44	technomancy	AWizzArd: swank-clojure.el or swank-clojure clojure server?
16:45	Chousuke	_na_ka_na_: well, the nodes will be just maps so you can just assoc the keys.
16:45	Chousuke	_na_ka_na_: in that regard it doesn't matter what you put in there.
16:45	Borkdude	technomancy: ok, sounds good. Now I have to find out how I do it using ELPA, can I just overwrite it or smth?
16:46	Borkdude	sorry, I'm still an Emacs n00b
16:46	AWizzArd	technomancy: I was not aware of those two so far. I still have a very old installation where I just do M-x Clojure to get a repl and Clojure-Mode. I typically did not start a swank server to which I then connected on port 4005 or something like that.
16:46	Chousuke	_na_ka_na_: so maybe using a map as a node is a good idea. try and experiment with a small prototype first
16:46	technomancy	Borkdude: the readme now shows a more foolproof method of using it. basically you don't need the elisp for swank-clojure anymore. on the Emacs side just get slime-repl and clojure-mode, and launch your swank server from the command-line
16:46	_na_ka_na_	Chousuke: yes, but the question is maps v/s struct-maps (v/s defrecord ?) .. coz I'm not going to dynamically add keys .. well maybe if my app runs for weeks along :D
16:47	tcrayford	_na_ka_na_: read steve yegge's article about systems that never stop
16:47	Chousuke	_na_ka_na_: well, a struct-map will be okay.
16:47	Borkdude	technomancy: and if I don't want to use the command line?
16:47	technomancy	AWizzArd: I'm using a relatively recent slime (two or three weeks old) with lein swank. I quit using M-x swank-clojure-project, but I think it still works
16:47	Chousuke	_na_ka_na_: though records are better.
16:47	technomancy	Borkdude: then it's more manual, but you can use this: http://p.hagelb.org/swank-launchers.html
16:47	sexpbot	"programming.el"
16:47	AWizzArd	technomancy: do you now always start a jvm with a swank-server listening and do slime-connect them from emacs?
16:48	technomancy	AWizzArd: that's what I do now, yes. it's much more foolproof; M-x swank-clojure-project had several nasty edge cases that confused a lot of people
16:48	Chousuke	_na_ka_na_: if you're using 1.2 and need the memory savings, you can use defrecord and then treat it as if it were a regular map I suppose :)
16:48	_na_ka_na_	tcrayford: link pls .. and ur is hard to see at first :) i wrote tracyford :P .. hope u dont mind
16:49	_na_ka_na_	Chousuke: exactly what i was thinking after i learnt protocols, datatypes today itself!
16:49	tcrayford	technomancy/AWizzArd: though swank-clojure-project lets you customize the jvm startup better than you can with lein atm
16:49	tcrayford	_na_ka_na_: http://steve-yegge.blogspot.com/2007/01/pinocchio-problem.html
16:49	sexpbot	"Stevey's Blog Rants: The Pinocchio Problem"
16:50	tcrayford	warning: Steve Yegge post, ie really really long
16:50	Chousuke	_na_ka_na_: the important thing in the beginning is not to marry yourself to a certain approach. programming to generic interfaces (ie. thinking of your data as just maps of stuff) often helps.
16:50	Chousuke	especially if you have a background in OOP :/
16:51	Borkdude	technomancy: maybe it's more foolproof, it's not n00bproof
16:52	_na_ka_na_	Chousuke: thats right, my background is OOP .. but the more I did it the more I felt this is wrong, we are just writing variables too much .. then I came across Clojure :D
16:55	_na_ka_na_	the sad thing now that I look back is we were thought not even one functional language in school, not even the topic of functional programming, immutability came across in so many "programming courses"
16:55	_na_ka_na_	first Java then C then Perl, Python ..
16:56	Borkdude	_na_ka_na_: what school was that
16:56	Borkdude	_na_ka_na_: I mean, what kind
16:56	Borkdude	_na_ka_na_: not that it sounds ridiculous, just curious
16:58	LauJensen	etate: ping
16:59	_na_ka_na_	Borkdude: not giving away the names .. but it was the... institute of technology
16:59	Borkdude	_na_ka_na_: only a few options then
17:00	_na_ka_na_	Borkdude: lets not name the options :P
17:01	Borkdude	_na_ka_na_: I'm just asking because I work at a 'school' as well
17:01	_na_ka_na_	Borkdude: Hmm, you teach or just work?
17:02	Borkdude	I teach
17:02	_na_ka_na_	Oh wow thats nice to hear, what subject(s) if you don't mind?
17:02	Borkdude	_na_ka_na_: I just started since March 1
17:04	Borkdude	_na_ka_na_: as of now, I teach things like Google Web Toolkit, a project using that and Object Oriented Design, some course around Oracle JDeveloper
17:04	_na_ka_na_	Borkdude: I like teachers :), wish you a rewarding career!
17:04	Borkdude	I hope to sneak in some Clojure somewhere sometime ;)
17:05	_na_ka_na_	Hehe ;) not let them know
17:05	AWizzArd	technomancy: what is swank.core/break doing?
17:05	Borkdude	_na_ka_na_: tnx
17:06	technomancy	AWizzArd: http://hugoduncan.org/post/2010/swank_clojure_gets_a_break_with_the_local_environment.xhtml
17:06	sexpbot	"Hugo Duncan : Swank Clojure gets a Break with the Local Environment"
17:06	technomancy	spoiler alert: it's awesome
17:06	_na_ka_na_	Chousuke: thanks for discussion, I'm off to test some of the ideas discussed.
17:06	tcrayford	technomancy: I've never had break succesfully work for me
17:10	tcrayford	does it only work from the repl?
17:10	alexyk	ninjudd: you know what a cool sideeffect of jiraph format is?
17:10	tcrayford	technomancy: (ie won't work using C-x C-e)
17:10	ninjudd	alexyk: what?
17:11	technomancy	tcrayford: it should work that way, but I usually invoke it via tests
17:11	alexyk	ninjudd: it's language-independent! you can read it from Scala presumably, or even from Python or C++
17:11	alexyk	whatever supports TC and protobuffers
17:12	joshua-choi	Question: In Clojure, in order to have two mutually recursive functions, must you use two vars? Is it impossible to create them in a let binding?
17:12	mmarczyk	joshua-choi: see letfn
17:12	ninjudd	alexyk: good point. didn't even think of that. i was just going for speed
17:12	joshua-choi	mmarczyk: Can letfn create mutually recursive functions?
17:12	mmarczyk	joshua-choi: that's its entire point :-)
17:13	alexyk	ninjudd: yeah, OTOH, compiling a proto is annoying, but you get portability too
17:13	ninjudd	alexyk: i'm working on lein tasks for compiling protobufs right now
17:13	alexyk	I'm sick of NPEs and will try Scala on a jiraph soon :)
17:13	joshua-choi	mmarczyk: Oh, I've been using it since it's cooler than (let [a (fn ...)] ...). That's cool. But only letfn can do that?
17:13	ninjudd	should make it easier
17:14	mmarczyk	joshua-choi: well you could conceivably use let with atoms (not sure why you'd want to, though)
17:14	alexyk	ninjudd: cool! as I understand, if you add a proto/ directory to classpath of a repl, you can keep compiling protos there without reloading repls, right?
17:14	mmarczyk	joshua-choi: anyway, letfn is there precisely for this purpose
17:15	mmarczyk	,(letfn [(ev? [n] (if (zero? n) true (od? (dec n)))) (od? [n] (if (zero? n) false (ev? (dec n))))] (ev? 10))
17:15	clojurebot	true
17:15	joshua-choi	mmarczyk: No, I don't want to use mutable structures. I have a problem with recursive nested functions that I've been using solving with vars, but now I've come up against a wall with them: namely, metadata.
17:15	alexyk	post-NPE-debugging stress disorder
17:16	joshua-choi	Oh dear, letfn seems to use a special form "letfn*".
17:16	joshua-choi	,`letfn*
17:16	clojurebot	letfn*
17:16	mmarczyk	joshua-choi: yeah, and let uses a special form "let", loop uses "loop" and fn uses "fn*"
17:16	mmarczyk	don't worry about it
17:16	ninjudd	alexyk: no, you'll still have to do 'lein proto' to recompile your proto files
17:16	joshua-choi	mmarczyk: I was hoping that I could utilize letfn's source code for my own parser library
17:17	joshua-choi	I am having to deal with recursive rules, and I don't want to use var-quoting anymore
17:17	alexyk	ninjudd: true, but I can do it from another dir and laod into a running repl by defining protobuffer there with just a class name
17:17	mmarczyk	joshua-choi: perhaps you can utilise letfn itself for your library? :-)
17:17	alexyk	clojurebot: take your NPE and shove it!
17:17	clojurebot	excusez-moi
17:17	mmarczyk	joshua-choi: note that there's no way around the lack of TCE for non-self-calls
17:19	joshua-choi	mmarczyk: Yes; I can unfortunately do little about that, I think; I can just hope that the stack stays small
17:19	mmarczyk	I guess so
17:19	joshua-choi	I thought that I could wrap all my rules in zero-argument functions, and that would fix it
17:19	mmarczyk	or maintain your own CPS stack, or use trampoline
17:19	joshua-choi	The mutual recursion reference problem I mean
17:19	mmarczyk	yup
17:20	joshua-choi	Yeah, no way I can use trampoline, I think; there's always many functions in between the mutually recursive functions
17:20	mmarczyk	that doesn't necessarily mean that you can't trampoline
17:21	mmarczyk	as long as you can wrap up all info on how the computation is to continue in a thunk, you can
17:22	joshua-choi	Really? I'll have to think hard about that
17:22	joshua-choi	Gee, it looks like I won't be done with FnParse 3 for a while again
17:22	mmarczyk	oh, this is about FnParse 3? cool :-)
17:22	joshua-choi	Yes. I'm trying to solve the problem of mutually recursive rules.
17:22	mmarczyk	do you have a public scratchpad somewhere...?
17:23	joshua-choi	Up to today it's been solved by var-quoting: #'
17:23	mmarczyk	just asking cause I'd be curious to have a look
17:23	joshua-choi	No, I don't
17:23	mmarczyk	oh well.
17:24	joshua-choi	Var-quoting isn't adequate, though: it introduces dependencies on mutable objects (the vars), it complicates validation (the vars can't be evaluated until...I don't even understand this part, actually), and it makes it impossible to use in a let form.
17:24	technomancy	clojurebot: swank-break is http://hugoduncan.org/post/2010/swank_clojure_gets_a_break_with_the_local_environment.xhtml
17:24	clojurebot	Ik begrijp
17:24	sexpbot	"Hugo Duncan : Swank Clojure gets a Break with the Local Environment"
17:25	joshua-choi	mmarczyk: What's a public scratchpad, by the way?
17:25	joshua-choi	Like a wiki?
17:27	mmarczyk	joshua-choi: well, I'm not sure myself :-)
17:27	mmarczyk	a wiki, a set of gists etc.
17:27	tcrayford	or just a TODO.txt on github
17:27	mmarczyk	you've got your 3.alpha.x tags on github
17:27	mmarczyk	so I guess I'll have a look at what you've committed lately
17:27	joshua-choi	Those aren't updated often. It'd be better to pay attention to my commits
17:27	mmarczyk	right.
17:27	joshua-choi	Yes. I also update a news page on my wiki from time to time
17:28	joshua-choi	I was waiting for Clojure 1.2 to release so Autodoc could work again, but I think I'll do one more revamp :)
17:28	mmarczyk	:-)
17:28	mmarczyk	um, sorry, I need to be off for now; bbl
17:29	joshua-choi	Talk to you later.
17:33	joshua-choi	Question. If a future JVM implements good tail-call optimization, would trampoline become obsolete?
17:45	neotyk	Hi *
17:46	neotyk	can someone explain why if I: (set! print-length 1) and than do (str '(1 2 3)) I will get (1 ...) I just can't see where it is happening in str function
17:49	_na_ka_na_	neotyk: Don't think its in the str function, has to be the print function ..
17:49	Borkdude	neotyk: maybe it's not happening in the str function
17:50	neotyk	at REPL than?
17:50	neotyk	but look: user> (str '(1 2 3))
17:50	neotyk	"(1 ...)"
17:51	neotyk	I get that one: user> '(1 2 3)
17:51	neotyk	(1 ...)
17:53	Borkdude	neotyk: I see what you mean
17:55	neotyk	~str
17:55	clojurebot	destructuring is http://clojure.org/special_forms#let
17:55	neotyk	source str
17:56	neotyk	http://github.com/tomfaulhaber/clojure/blob/7b4b8e18c0d28e03e7c66f54bc441ef355ceb5ed/src/clj/clojure/core.clj#L401
17:56	neotyk	where is this magic cut off happening ?
17:58	neotyk	just checked that it is not just emacs, normal repl does the same
18:01	arohner	anyone have experience with clj-cont?
18:02	tcrayford	no, but I think I understand continuations
18:02	tcrayford	(if I was going to use continuations in clojure, I'd probably use the cont-m monad from c.c.monads)
18:02	arohner	I think I understand continuations, I'm wondering how reliable clj-cont is compared to say, scheme. Any weird gotchas?
18:03	_na_ka_na_	neotyk: maybe the .toString method?
18:03	tcrayford	no idea on that count then
18:04	neotyk	_na_ka_na_: but .toString is called on each element of list, not on a list
18:07	arkahn	neotyk: set! is often used for Java interop - I would think it's setting something in java.lang.String
18:09	arkahn	neotyk: printf related? I'm probably grasping ...
18:11	neotyk	arkahn: I have no idea, str source doesn't indicate this kind of behavior at all
18:11	neotyk	I'm trying to find usages of print-length
18:11	arkahn	neotyk: nvm, I was wrong. print-length is located in core_print.clj in the actual clojure source
18:12	LaPingvino	Hello hubert :)
18:12	LaPingvino	Joop here
18:12	neotyk	LaPingvino: Hello
18:12	LaPingvino	how are you?
18:12	neotyk	goed, en jij
18:12	LaPingvino	I am playing a bit with the newest compojure... it did change enough to make me search a lot to get it all running :S
18:13	LaPingvino	met mij ook :)
18:13	kotarak	(doc number?)
18:13	clojurebot	"([x]); Returns true if x is a Number"
18:13	arkahn	neotyk: (doc print-length) <- have you tried that? Hopefully I'm helping what you're asking.
18:13	LaPingvino	you know how to do a serve-file now?
18:13	LaPingvino	I will put the question in #compojure as well :)
18:14	kotarak	,(some number? [nil nil nil 5 nil nil])
18:14	clojurebot	true
18:15	kotarak	,(some #(and (number? %) %) [nil nil nil 5 nil nil])
18:15	clojurebot	5
18:15	neotyk	arkahn: yes, though didn't help :(
18:15	LaPingvino	neotyk: any idea?
18:15	neotyk	LaPingvino: no idea, I'm serving files via apache
18:16	LaPingvino	ah okay
18:17	arkahn	neotyk: the doc on print-length looks like it totally explains the behavior. Can you re-state what you're asking?
18:18	neotyk	why (str '(1 2 3)) gives "(1 ...)" if (set! print-length 1)
18:20	arkahn	to what I'm understanding, print-length set to 1 will only print the first item of a collection, with all remaining items represented by the ellipsis
18:20	arkahn	,(do (set! print-length 1) (str '(1 2 3)))
18:20	clojurebot	java.lang.IllegalStateException: Can't change/establish root binding of: print-length with set
18:21	_na_ka_na_	,(let [s (str '(1 2 3)) s1 (binding [print-length 1] (str '(1 2 3))) s2 (binding [print-length 2] (str '(1 2 3)))] [s s1 s2])
18:21	clojurebot	["(1 2 3)" "(1 ...)" "(1 2 ...)"]
18:21	alexyk	I get a StackOverflow, and printStackTrace shows a huge block of internal things, like clojure.lang.LazySeq.sval/seq/RT.seq, and none of my files' lines. How do I debug it?
18:21	arkahn	and then if you set print-length to logical false it'll print the whole collection
18:23	_na_ka_na_	and this will prove that its not just repl printing thats using print-length ..
18:23	_na_ka_na_	,(let [s (str '(1 2 3)) s1 (binding [print-length 1] (str '(1 2 3))) s2 (binding [print-length 2] (str '(1 2 3)))] [(count s) (count s1) (count s2)])
18:23	clojurebot	[7 7 9]
18:24	alexyk	can apply cause StackOverflow?
18:25	alexyk	with a very long arg list?
18:25	tcrayford	I think clojure arg lists fail somewhere around 40
18:25	alexyk	looks like it
18:25	alexyk	strangely no source line, apparently it overflown the said stack
18:26	tcrayford	,(apply + (repeat 100 10))
18:26	clojurebot	1000
18:26	arohner	clojure functions can take an infinite number of arguments
18:26	alexyk	so that's not it
18:26	tcrayford	nope
18:26	arohner	alexyk: my guess is the function being applied has a 'normal' stack overflow
18:27	alexyk	arohner: why would it? is apply nesting?
18:28	arohner	alexyk: no, I was saying that I doubt apply is causing a stack overflow. it's more likely either the function being applied, or the seq that is passed to apply
18:28	alexyk	,(apply max (range 1000000))
18:28	clojurebot	999999
18:29	arohner	alexyk: apply has been known to cause heap overflows. some kind of head-holding going on in some circumstances
18:29	_na_ka_na_	neotyk: found anything?
18:29	neotyk	_na_ka_na_: still nothing
18:30	neotyk	I know that print-method multimethod does this limiting tirck
18:30	neotyk	but can't find a link between str and print-method
18:31	neotyk	s/tirck/trick/
18:31	sexpbot	but can't find a link between str and print-method
18:32	arohner	neotyk: the repl prints the return values of expressions
18:32	arohner	it's the P in Read Eval Print
18:32	neotyk	,(binding [print-length 1] (str '(1 2)))
18:32	clojurebot	"(1 ...)"
18:33	_na_ka_na_	neotyk: yup i'm stuck thr too
18:33	_na_ka_na_	neotyk: esp. see this ..
18:34	_na_ka_na_	,(let [s (str '(1 2 3)) s1 (binding [print-length 1] (str '(1 2 3))) s2 (binding [print-length 2] (str '(1 2 3)))] [(count s) (count s1) (count s2)])
18:34	clojurebot	[7 7 9]
18:34	arohner	neotyk: I don't understand what's wrong with that example
18:34	_na_ka_na_	arohner: can you see the above example?
18:34	neotyk	arohner: look at source of str
18:35	neotyk	and please do tell why it prints "(1 ...)"
18:35	alexyk	is there a simple way to find a max of a list without (apply max that-list)?
18:35	neotyk	I think key here is '('
18:37	neotyk	I don't see anything in str source that would make it print '('
18:37	arohner	neotyk: ok, now I understand what you mean
18:38	_na_ka_na_	alexyk: whats wrong with apply max?
18:38	neotyk	I should not be saying print, when we talk about str fn
18:38	alexyk	_na_ka_na_: I'm not sure what causes StackOverflow
18:38	_na_ka_na_	yup thats why i printed counts
18:39	ipostelnik	looks like clojure.lang.PersistentList#toString respect print-length
18:39	_na_ka_na_	,(apply max (into [] (range 100000000)))
18:39	clojurebot	Execution Timed Out
18:39	alexyk	I am thinking of apply; I don't have any recursion, and trace shows LazySeq.sval=>seq=>RT.seq ad infinitum
18:40	neotyk	I think I got it: IPeristentList has it's own .toString that delegate to print-method
18:40	_na_ka_na_	but its a PersistentList right?
18:40	_na_ka_na_	,(class '(1 2 3))
18:40	clojurebot	clojure.lang.PersistentList
18:42	remleduff	,(RT/printString '(1 2 3))
18:42	clojurebot	java.lang.Exception: No such namespace: RT
18:42	remleduff	,(clojure.lang.RT/printString '(1 2 3))
18:42	clojurebot	"(1 2 3)"
18:43	arkahn	I wonder if all/most collection .toString's delegate to print-method
18:43	_na_ka_na_	it looks that way, but the question is how?
18:43	_na_ka_na_	can you point out in the source?
18:43	remleduff	ASeq is the abstract base of most of the collections, its toString calls RT.printString which is where the magic happens
18:44	_na_ka_na_	ya ..
18:44	_na_ka_na_	,(binding [print-length 1] (clojure.lang.RT/printString '(1 2 3)))
18:44	clojurebot	"(1 ...)"
18:45	_na_ka_na_	remleduff: but can you point out in the source? i'm unable to see
18:45	remleduff	You mean point out the delegation or what does the cut-off?
18:45	neotyk	ASeq has toString that calls RT/printString
18:46	neotyk	PersistentList extends ASeq
18:46	neotyk	so in str it is arity 1 case
18:46	_na_ka_na_	yup it is ..
18:47	neotyk	though I would have though that is is last case
18:47	_na_ka_na_	remleduff: i mean point out where exactly the magic is happening in RT.printString
18:48	LaPingvino	neotyk: found it :)
18:48	neotyk	it must be calling print-method multimethod
18:48	arkahn	that's what I see, too (the print-method multimethod)
18:49	_na_ka_na_	but the question is how does it reach thr?
18:49	arkahn	what is RT ?
18:50	_na_ka_na_	its a class in the Clojure java source
18:51	alexyk	this fragment of a let causes stack overflow: http://paste.pocoo.org/show/215514/ -- why?
18:52	neotyk	RT.printString -> print -> printInnerSeq
18:52	neotyk	and I'm still missing link to print-method
18:52	neotyk	LaPingvino: so how do you serve-file?
18:52	alexyk	I've tried to stick a doall at random. Googling for StackOverflow shows notions of filters closing over locals as culprits; I do have locals in the map's fn. The list it works on is about 300,000 long
18:53	_na_ka_na_	i see it!
18:54	alexyk	_na_ka_na_: what is it you see?
18:54	_na_ka_na_	neotyk: if you are looking the source of clojure.lang.RT/printString .. see the lines ..PR_ON.invoke(x, w);
18:55	islon	defmethod body has an implicit do?
18:55	neotyk	oh yeah, it even has a comment on top saying "//call multimethod"
18:56	islon	thanks
18:56	_na_ka_na_	oh i just glossed all over that comment :(
18:57	_na_ka_na_	its 2 light
18:57	neotyk	rest of this method is commented out
18:57	remleduff	All of the multimethod implementations that get called for the core datastructers are defined in clojure/lang/core_print.clj, specifically the one that looks like (defmethod print-method clojure.lang.ISeq ...)
18:57	neotyk	syntax highlighting borked
18:57	_na_ka_na_	nope its not commented out is it?
18:58	remleduff	I think everything except for the multimethod invocation is just there for bootstrapping/debugging
18:58	neotyk	islon: I did not answer your question
18:59	_na_ka_na_	atleast its not commented out in the main .. //* .. //*/
19:00	_na_ka_na_	remleduff: can you explain how does in help in bootstrapping/debugging
19:00	neotyk	oh my so evil
19:00	neotyk	it is not commented out
19:00	neotyk	/* is not multiline comment in java
19:00	neotyk	///*
19:00	neotyk	/
19:01	neotyk	the one in the source
19:01	alexyk	hmm -- I traced the overflow to let: ustats (into {} ustats) where ustats is computed above now as a huge vector. Possible?
19:01	islon	neotyk, i tested in the repl
19:01	remleduff	I imagine it just lets rich debug stuff until the actual print-method multimethods get defined by clojure/core_print.clj. Once the pr-on var is defined in core.clj, none of that method gets called except for the very first multimethod invocation.
19:01	_na_ka_na_	neotyk: well we solved one mystery today .. but the point is that the str docs should say so!
19:03	neotyk	_na_ka_na_: did we? I still don't get why arity 1 is used
19:03	alexyk	actually, wrong -- a doall on the vector forces overflow
19:03	_na_ka_na_	remleduff: I see ..
19:03	_na_ka_na_	neotyk: Oh thats easy
19:04	neotyk	do tell
19:04	_na_ka_na_	,(str [1 2 3])
19:04	clojurebot	"[1 2 3]"
19:04	_na_ka_na_	[1 2 3] is one object ...
19:04	neotyk	,(str '(1 2 3) [1 2 3])
19:04	_na_ka_na_	where as
19:04	clojurebot	"(1 2 3)[1 2 3]"
19:04	_na_ka_na_	,(apply str [1 2 3])
19:04	clojurebot	"123"
19:04	_na_ka_na_	,(str 1 2 3)
19:04	clojurebot	"123"
19:05	neotyk	got it
19:05	_na_ka_na_	are both same, multiple arity
19:05	neotyk	we did solve one mystery
19:05	_na_ka_na_	neotyk: I guess you should notify the developers involved
19:05	neotyk	_na_ka_na_: that it works?
19:06	_na_ka_na_	neotyk: that the doc of str should reflect the print-length thingy
19:06	remleduff	Here's a question for you, now that we think we know how the printing works, is ASeq.toString actually being called?
19:07	_na_ka_na_	thats how it reaches RT.printString right?
19:08	_na_ka_na_	str -> ASeq.toString -> RT.printString -> print-method -> print-sequential
19:08	remleduff	I don't think so ;)
19:08	_na_ka_na_	then?
19:09	remleduff	clojure.main/repl evaluates your form then calls "print" on it, which by default is the method "prn"
19:09	remleduff	prn uses the pr-on multimethod
19:10	remleduff	Sorry, pr-on isn't a multimethod, but that calls the print-method multimethod
19:10	neotyk	remleduff: str fn
19:10	alexyk	can something like let ... stats (assoc :key val) in a nested fn of a long map cause overflow?
19:10	_na_ka_na_	remleduff: but i'm not even calling the print
19:10	remleduff	Oh, bah! :)
19:11	remleduff	Yeah, you're right
19:11	neotyk	remleduff: arity 1 case
19:11	neotyk	calles toString on PertistentList
19:11	ninjudd	alexyk: StackOverflow usually means infinite loop
19:11	neotyk	that takes impl from ASeq
19:11	alexyk	ninjudd: I don't get it on a shorter data
19:11	remleduff	Yeah, didn't realize you were calling str, thought you were just printing it at the repl
19:12	alexyk	I only get it if I add a doall to a map
19:12	ninjudd	hmm. let me look at your code fragment
19:12	_na_ka_na_	that's why the docs of str should reflect print-length
19:12	alexyk	the doall there causes overflow
19:12	_na_ka_na_	can anyone chk in 1.1 ?
19:12	alexyk	http://paste.pocoo.org/show/215514/
19:13	ninjudd	alexyk: is this inside a loop?
19:13	arkahn	_na_ka_na_: check for what ?
19:14	ninjudd	or are you using recursion?
19:14	remleduff	str docs just say it calls toString, and toString has always been super-loosely defined
19:14	alexyk	ninjudd: no, it's a piece of let which explicitly iterates over days. it fails on the very first one
19:14	arkahn	oh .. yeah
19:15	alexyk	ustats is a map with 300,000 structs
19:15	remleduff	Whenever you call toString in java, you should assume that eventually you're going to run across a programmer who was hungry and just decided to make his class print, "I like pie" ;0
19:16	_na_ka_na_	neotyk: i guess thats fine then .. but I'm sure there would have been / will be many fellows who'll just find the hard way
19:16	arkahn	having print-length affect str is bad - seems like it should be more than documented, it should be changed
19:17	arkahn	it was fun trying to keep up with you guys, though ... I learned along the way ; )
19:17	remleduff	What do you expect str to do if you do (str (range)) ?
19:17	neotyk	arkahn: I'm fine with it doing so, or at least to have a variant that has this cut off behavior, but docs should reflect it
19:19	alexyk	ninjudd: in fact, forget it, it may be above it... am doalling it
19:20	alexyk	I had an init-less reduce which suddenly barfed on count'ing its result
19:20	_na_ka_na_	,((fn [n] (when (pos? n) (x (dec n)) (nil? nil))) 6280)
19:20	clojurebot	java.lang.Exception: Unable to resolve symbol: x in this context
19:20	_na_ka_na_	blah
19:20	remleduff	Oh, fortunately, LazySeq doesn't delegate
19:21	remleduff	Maybe ASeq should bind print-length to nil before calling printString
19:21	ninjudd	alexyk: so you figured it out?
19:21	alexyk	or it's a nested remove... man, lazy bastartds are tricky!
19:21	alexyk	ninjudd: not yet
19:22	alexyk	my graphs are huge
19:22	ninjudd	hehe
19:22	_na_ka_na_	,(letfn [(x [n] (when (pos? n) (x (dec n)) (nil? nil)))] (x 6280))
19:22	clojurebot	java.lang.StackOverflowError
19:22	alexyk	I got more Twitter user than you mormons :)
19:22	ninjudd	huh?
19:22	alexyk	ninjudd: in your genealogy :)
19:22	_na_ka_na_	wierd for me 6280 works and 6281 fails
19:23	ninjudd	oh, we do genealogy way better than the mormons
19:23	ninjudd	they're genealogy 1.0
19:23	ninjudd	plus we don't baptize our users
19:23	_na_ka_na_	How do I easily figure out at what point my stack will blow off?
19:23	alexyk	I may be dense today, but this seems the line du jour candidate for overflow: (reduce (fn [sums terms] (map + sums terms)) (remove nil? sum-terms)) ; why?
19:24	lancepantz	we do tell them they're going to hell if they quit using our site though
19:24	alexyk	doall'ing remove didn't save it
19:24	tomoj	_na_ka_na_: why not just stop blowing the stack?
19:24	alexyk	adding [0 0 0] init doesn't save it either. Each element of sum-terms is a tuple of 3 numbers
19:25	_na_ka_na_	tomoj: well thats ideal :) but say just for fun / knowing it
19:25	alexyk	I simply compute all 3 sums in one pass, for each position
19:25	ninjudd	lancepantz: isn't that standard practice with all internet companies?
19:25	tomoj	ah, I dunno
19:25	tomoj	I think it probably depends on how big the stack frames are
19:25	alexyk	or, will nested (map + sums terms) lazily sit there??
19:26	ninjudd	alexyk: can you update the code snippet with the reduce?
19:26	lancepantz	that's why facebook doesn't let users quit, just trying to protect them from going to hell
19:26	tomoj	e.g. if the functions close over more variables, you'll run out sooner, I'd think?
19:26	_na_ka_na_	hmm that sounds an idea, i'll quickly test it
19:27	_na_ka_na_	yup you're right
19:27	_na_ka_na_	so is there a way to how the size of stack frames?
19:27	_na_ka_na_	know* the size
19:28	alexyk	yes! that nested (map + sums terms) had to be doall'ed into submission, like 3 mormonic wives who don't use geni.com! :)
19:28	remleduff	alexyk: Every map returns a LazySeq, so you end up with (+ LazySeq (+ LazySeq (+ LazySeq...)))) in pseudo-stack notation
19:28	alexyk	map is lazy and dangerous -- my new motto
19:28	remleduff	nm, you got it
19:29	alexyk	remleduff: thx, too! this was evil and took long on a huge graph to locate
19:29	neotyk	thanks _na_ka_na_ remleduff for helping in figuring str out
19:30	remleduff	I run into laziness problems with map all the time still
19:30	alexyk	new Clojure T-shirt: doall
19:30	remleduff	I mean self-imposed laziness problems
19:30	alexyk	did you doall your nested map today?
19:31	alexyk	for every lazy map, there's a doall
19:35	islon	does this works: (defn foo [{bar :bar :as stuff}] bar)?
19:36	tcrayford	,(let [{bar :bar :as stuff} {:bar 1 :foo 2} ] stuff)
19:36	clojurebot	{:bar 1, :foo 2}
19:37	remleduff	stuff is extraneous there, but yeah
19:37	tcrayford	yeah, but shows that the destructuring works like that
19:37	remleduff	Could also use (defn [{:keys [bar]}] bar)
19:38	remleduff	Too many bars
19:38	islon	i was just asking if :as worked with maps, thanks =)
19:41	alexyk	"just doall it" <-- my final slogan for today
19:42	tcrayford	I need to get a t-shirt with "unqualified lisp chainsaw operator" at some point
19:44	remleduff	(let [{:keys [a] :syms [b] :strs [c] :as foo} {:a 1 'b 2 "c" 3}] [a b c foo])
19:45	remleduff	(-> it doall)
19:45	mario-goulart	Hi. I'm trying to execute a clojure script from java. The clojure script access java methods. I'm getting some errors.
19:45	mario-goulart	Here's what I'm trying: http://paste.lisp.org/display/99436
19:47	remleduff	Why do you think (. bar baz a b) should work? What are bar and baz?
19:48	mario-goulart	remleduff: that's my interpretation from I read at http://clojure.org/java_interop
19:48	mario-goulart	I'm new to clojure, BTW.
19:48	remleduff	You need to add a "bar" parameter to your function in clojure, and then pass "this" when you call the function
19:50	remleduff	Or, since your Bar class is static, you could actually do (. Bar baz 1 2), but note that this is kind of old style and it's bad because your Bar is in the default package, so I don't think it is doing what you think it's doing.
19:51	mario-goulart	remleduff: thanks. What'd be the proper way for doing that?
19:51	remleduff	Alternatively, (Bar/baz 1 2) is the way to do it nowadays. But Bar should really be in a package
19:51	remleduff	Then it would be (import package.Bar) (Bar/baz 1 2)
19:52	MadWombat	stupid question, what is a simple method of removing last character from a string?
19:52	mario-goulart	remleduff: thanks for the tips. I'm gonna try that.
19:54	MadWombat	chop seems to work, anyone using enlive? is there a way to avoid constructs like (chop (chop (first (:content (first (select item store-name-selector))))))
19:54	remleduff	Or make baz not a static method, and pass an object to invoke named "object" ... (defn foo [object a b] (.baz object a b)). In that case, you'd use the this pointer from java
19:54	tcrayford	,(reduce str (drop-last "foo"))
19:54	clojurebot	"fo"
19:54	remleduff	MadWombat: (apply str (drop-last "Hello"))
19:54	mario-goulart	remleduff: one more thing: is it a problem is the package Bar loads the clojure script and the script imports Bar? Should I make the Bar package something isolated from the script loader?
19:55	mario-goulart	problem if*
19:55	MadWombat	remleduff: yes, chop from str-utils2 seems to work as well
19:55	remleduff	Wonder if there's a reason to prefer reduce or apply
19:55	tcrayford	reduce is often faster
19:55	tcrayford	especially with + (iirc)
19:57	remleduff	mario-goulart: I don't think so, just don't think that they get any special access to each other because of that
19:57	mario-goulart	remleduff: right. Thanks.
20:00	Raynes	Just a bit of an announcement: I've put out a new version of http://www.try-clojure.org/. Thanks to some work by Licenser, def has been allowed. There is an also short, totally incomplete first-cut of a tutorial that I threw up in about an hour. More serious work on that will start tomorrow.
20:00	sexpbot	"TryClojure"
20:00	Raynes	Good night, friends. <3
20:01	tcrayford	Raynes:
20:01	tcrayford	unless you've gone
20:02	tcrayford	you've misplaced a "they're" on that page, should be "their"
20:05	ninjudd	Raynes: nice! how about an iphone version of the site?
20:05	Raynes	tcrayford: I'll fix that in a moment. I've not gone yet. Feeding my snake.
20:05	remleduff	Raynes: Is it intentionaly that I can't copy or paste?
20:05	Raynes	ninjudd: I don't have an iphone to test that on.
20:06	tcrayford	neat then
20:06	Raynes	remleduff: It uses jquery-console. There doesn't seem to be a way to allow copypasta.
20:06	tcrayford	I added a github issue in case you had gone
20:07	Raynes	tcrayford: Thanks for the catch.
20:07	Raynes	remleduff: Note that none of the trylanguage sites allow copypasta.
20:07	Raynes	It's helpful for learning, but not so much for practicality.
20:07	ninjudd	Raynes: oh, the source is on github. sweet!
20:08	Raynes	Indeed.
20:08	ninjudd	i guess jQuery console is where the work would need to be done to get it working on iphone
20:13	Raynes	tcrayford: Fixed.
20:14	tcrayford	Raynes: good to hear
20:14	tcrayford	night all
20:15	Raynes	Night here as well. <3
20:21	Raynes	Actually, ninjudd: I was just thinking, and it would be possible to somewhere down the line support a more HTML-based REPL or something. Kind of like what I had originally. I can just add another interface over it and call it m.try-clojure.org. :p
20:22	tomoj	what, like page reload per form eval'd?
20:22	tomoj	s/re//
20:22	sexpbot	what, like page load per form eval'd?
20:22	mario-goulart	Hmmm. Still no luck: http://paste.lisp.org/display/99436#1
20:22	Raynes	tomoj: If necessary.
20:22	Raynes	tomoj: Whatever it takes.
20:23	tcrayford	Raynes: for an iphone app you wouldn't need that
20:24	Raynes	Anyway, I'll point out that try-clojure has an API in there too. http://www.try-clojure.org/magics?code=urlencodedcode, so anybody could write their own interface around that for whatever they want.
20:24	ninjudd	Raynes: that would be nice
20:24	tcrayford	/s/a/at a
20:24	Raynes	I'd be tickled if someone wrote an IPhone app using try-clojure.
20:25	Raynes	Anyway, I'm off to sleep. For real this time. ;)
20:25	tcrayford	heh
20:25	tcrayford	I should go as well
20:25	tomoj	typing clojure on the iphone sounds painful
20:25	ninjudd	Raynes: hmm, can't get the API to load
20:25	tomoj	unless the app has some tricked out editing interface
20:25	ninjudd	Raynes: java.lang.Exception: Unable to resolve symbol: urlencodedcode in this context
20:26	tomoj	what would paredit be in multitouch? :D
20:26	Raynes	ninjudd: It tried to execute that code. Try it with actual code, silly.
20:26	ninjudd	tomoj: wouldn't be as bad with gestures for parens, brackets etc
20:26	tomoj	and completion
20:26	ninjudd	Raynes: heh
20:30	Plouj	does anyone knelse have problems with readLine in slime/swank/eclipse?
20:31	Plouj	s/eclipse/emacs/
20:31	sexpbot	does anyone knelse have problems with readLine in slime/swank/emacs?
20:33	Plouj	:)
20:33	Plouj	s/knelse/else/
20:33	sexpbot	:)
20:35	Plouj	once readLine is called, i can't get back to the prompt in slime-repl clojure
20:38	lancepantz	:)
20:38	lancepantz	s/)/(/
20:38	sexpbot	Incorrectly formatted regular expression: )
20:38	ninjudd	foo bar
20:38	ninjudd	s/foo/bar/
20:38	sexpbot	bar bar
20:38	lancepantz	s/\)/\(/
20:38	sexpbot	s/foo/bar/
20:38	ninjudd	s/bar/baz/
20:38	sexpbot	s/\)/\(/
20:38	lancepantz	:)
20:39	lancepantz	s/\)/\(/
20:39	sexpbot	:(
20:39	ninjudd	foo bar
20:39	ninjudd	s/foo/bar/
20:39	sexpbot	bar bar
20:39	ninjudd	s/bar/baz/
20:39	sexpbot	s/foo/baz/
20:39	lancepantz	that's awesome
20:43	remleduff	mario-goulart: I think your problem is that class Bar isn't in directory "bar" which java expects for packages. Also, you need to change your main class to "bar.Bar" on your java invocation line.
20:43	tomoj	s.awesome.annoying.
20:43	tomoj	cool, it doesn't pick up on other delimeters :)
20:45	remleduff	mario-goulart: Also, your foo.clj lost its namespace
20:46	mario-goulart	remleduff: you mean the (ns user) declaration?
20:46	remleduff	mario-goulart: Yeah, in the paste at least. That will make RT.var("user", "foo") not find anything
20:48	mario-goulart	remleduff: Thanks a lot. The directory structure and (ns user) make it work. I can get 6 as output. :-)
20:49	remleduff	Cool, good luck :)
20:49	mario-goulart	Thank you. :-)
20:55	MadWombat	hmm... seems like enlive encodes non-breaking space into some sort of strange character... wonder how to remove it
21:11	SynrG	win 18
21:11	SynrG	bluh
21:20	maxhodak	is it possible to destructure a list into a list-of-lists?
21:20	maxhodak	i.e.,
21:21	maxhodak	("foo" for 1 at 3214 where "bar")
21:21	maxhodak	into something like
21:21	maxhodak	[myvar [[key value]]] ?
21:21	maxhodak	([for 1] [at 3214] [where "bar"])
21:22	tomoj	I don't think that's possible, but maybe something like this?
21:23	dnolen	,(partition 2 (for 1 at 3214 where "bar"))
21:23	clojurebot	java.lang.RuntimeException: java.lang.IllegalArgumentException: Wrong number of args passed to: core$for
21:23	tomoj	,(for [[k v] (partition 2 '(for 1 at 3214 where "bar"))] [k v])
21:23	clojurebot	java.lang.RuntimeException: java.lang.RuntimeException: java.lang.IllegalArgumentException: Wrong number of args passed to: core$for
21:23	tomoj	whoops
21:23	dnolen	,(partition 2 '(for 1 at 3214 where "bar"))
21:23	clojurebot	java.lang.RuntimeException: java.lang.IllegalArgumentException: Wrong number of args passed to: core$for
21:23	tomoj	,3
21:23	clojurebot	3
21:23	tomoj	weird
21:24	tomoj	$(for [[k v] (partition 2 '(for 1 at 3214 where "bar"))] [k v])
21:24	sexpbot	Wrong number of args passed to: core$for
21:24	dnolen	,(partition 2 '(for-blah 1 at 3214 where "bar"))
21:24	clojurebot	((for-blah 1) (at 3214) (where "bar"))
21:24	tomoj	I'm confused
21:25	maxhodak	hmm
21:26	tomoj	why are sexpbot and clojurebot both broken?
21:26	tomoj	$(partition 2 '(for 1 at 3214 where "bar"))
21:26	sexpbot	Wrong number of args passed to: core$for
21:27	tomoj	or maybe they're using a different version of partition?
21:27	tomoj	,(doc partition)
21:27	clojurebot	"([n coll] [n step coll] [n step pad coll]); Returns a lazy sequence of lists of n items each, at offsets step apart. If step is not supplied, defaults to n, i.e. the partitions do not overlap. If a pad collection is supplied, use its elements as necessary to complete last partition upto n items. In case there are not enough padding elements, return a partition with less than n items."
21:27	tomoj	looks ok to me, very strange
21:27	tomoj	Licenser_: ping
21:27	maxhodak	it works for me in repl so
22:55	johnmn3_	test
22:56	johnmn3	how do you do the opposite of (str .. ?
22:56	johnmn3	like, return the contents of "(pr \"hi\")"
22:56	johnmn3	though I don't want them evaluated by the reader.
22:56	johnmn3	which read-string seems to be doing
22:57	johnmn3	print, maybe
23:00	johnmn3	no, read-string should work
23:00	johnmn3	,(let [s (read-string "2")] (pr (str "1 " s)))
23:00	clojurebot	"1 2"
23:01	johnmn3	,(let [s (read-string "2")] (pr (+ 1 s)))
23:01	clojurebot	3
23:01	johnmn3	rather
23:12	johnmn3	I'm getting a java.lang.Exception: EOF while reading
23:12	dakrone	johnmn3: did you close all your parens?
23:12	johnmn3	last call was clojure.lang.LispReader.read
23:13	johnmn3	while doing a read-string
23:13	johnmn3	yea, I did. strangely, it's like read-string is sending the data into a reader
23:14	dakrone	what string are you reading?
23:15	johnmn3	and I'm getting an EOF on the data I'm sending into read-string to send a treemodel the datastructure to be displayed.
23:17	johnmn3	I mean, read-string is un-stringifying strings pulled from a gui component and feeding them to a clojure.inspector/tree-model, which is in turn sent to a JTree.
23:17	dakrone	do you know the actual text of the string being passed to read-string?
23:18	johnmn3	I guess I should verify
23:18	johnmn3	should be whatever it scrapes from the textarea, like "(println \"hi")"
23:18	johnmn3	should be whatever it scrapes from the textarea, like "(println \"hi\")"
23:24	johnmn3	meh, theres got to be a missing parens in my code somewhere
23:24	dakrone	anyone know why I'm having problems with variable-arity protocols? http://gist.github.com/405912
23:40	brweber2	If I have a seq and I want to get the items (but not in a seq) what function should I use? ie I want to go from ((+ 2 3) \a) to (+ 2 3) \a
23:40	tomoj	functions can't return multiple values
23:41	tomoj	,(let [[a b] [(+ 2 3) \a]] [a b])
23:41	clojurebot	[5 \a]
23:42	tomoj	,(let [s [(+ 2 3) \a]] [(first s) (second s)])
23:42	clojurebot	[5 \a]
23:42	brweber2	I just want to "unroll" a sequence. tomoj so de-structuring won't work if I don't know the size of the seq will it?
23:42	tomoj	correct
23:42	tomoj	unrolling a sequence of an unknown size doesn't really make any sense
23:43	tomoj	assuming you're not willing to drop some off the end
23:43	tomoj	maybe just explain what you're actually trying to do
23:44	tomoj	is it a string you want in the end? like (your-fn [(+ 2 3) \a]) == "5 \a" ?
23:45	brweber2	tomoj no, more like I want to do (list fun-name ... ) in a macro
23:46	brweber2	but the ... is a lazy seq
23:46	brweber2	and I just want the values of the seq
23:46	tomoj	,`(list ~@[(+ 1 2) \a])
23:46	clojurebot	(clojure.core/list 3 \a)
23:47	tomoj	,`(list ~@`[(+ 1 2) \a])
23:47	clojurebot	(clojure.core/list (clojure.core/+ 1 2) \a)
23:48	johnmn3	,(map read-string '("1" ""))
23:48	clojurebot	java.lang.RuntimeException: java.lang.Exception: EOF while reading
23:49	johnmn3	that's my problem right there
23:49	brweber2	tomoj thanks!
23:49	johnmn3	,(map read-string '("1" "2" "hi"))
23:49	clojurebot	(1 2 hi)
23:50	johnmn3	,(map read-string '("1" "2" "hi" ""))
23:50	clojurebot	java.lang.RuntimeException: java.lang.Exception: EOF while reading
23:50	tomoj	,(read-string "")
23:50	clojurebot	java.lang.RuntimeException: java.lang.Exception: EOF while reading
23:50	johnmn3	hmm, it's the empty quotes
23:50	johnmn3	so filter ""
23:53	johnmn3	,(map read-string (remove #(= "" %) '("1" "" "hi")))
23:53	clojurebot	(1 hi)
23:54	tomoj	,(map read-string (remove #{""} '("1" "" "hi")))
23:54	clojurebot	(1 hi)