#clojure – 2009-06-08

2009-06-08

01:59	tbatchelli1	anyone knows if there is already a way how to convert a clojure map into a java map (for example a HashMap)?
02:04	hiredman	,(import java.util.HashMap)
02:04	clojurebot	java.util.HashMap
02:04	hiredman	,(import 'java.util.HashMap)
02:04	clojurebot	java.util.HashMap
02:04	hiredman	,(HashMap.)
02:04	clojurebot	#<HashMap {}>
02:04	hiredman	,(HashMap.{:a 1 :b 2})
02:04	clojurebot	#<HashMap {:b=2, :a=1}>
02:05	hiredman	,(ancestors {})
02:05	clojurebot	nil
02:05	hiredman	,(ancestors (class {}))
02:05	clojurebot	#{clojure.lang.Obj clojure.lang.Seqable java.util.Map clojure.lang.IPersistentMap clojure.lang.Associative java.io.Serializable clojure.lang.AFn clojure.lang.IMeta clojure.lang.Counted clojure.lang.IPersistentCollection clojure.lang.IObj java.util.concurrent.Callable java.lang.Iterable java.lang.Object clojure.lang.APersistentMap java.lang.Runnable clojure.lang.IFn}
02:09	tbatchelli1	hiredman: thanks. does that mean that I can call (. doSomethingWithMap javaObject (HashMap. {a:1 b:2})
02:11	hiredman	clojure maps are java Maps
02:12	hiredman	clojure maps are java Maps, they just throw an exception if you try to mutate them
02:14	tbatchelli1	that's what I thought, but I can't seem to be able to pass a map as a parameter to a java method that expects one.... I'll try to figure out what's wrong with my code
02:20	tbatchelli1	hiredman: thanks! I figured the error in my code... :)
08:38	chouser	(defn searcher-path [#^IndexSearcher searcher]
08:38	chouser	(let [#^FSDirectory fsdir (.. searcher getIndexReader directory)
08:38	chouser	#^String path (.. fsdir getFile getPath)]
08:38	chouser	oh, dear
08:38	chouser	sorry.
09:17	ivan	anyone know where terraclojure went? github project seems to be deleted.
09:18	ivan	oh, maybe that was old
10:22	rhickey	Chouser: nice!: http://groups.google.com/group/clojure/browse_thread/thread/9d3215ed863f1586/0cb4cf7abf269740?show_docid=0cb4cf7abf269740
10:22	chouser	:-) thanks
10:22	chouser	it'll have to do until c-in-c is done.
10:23	rhickey	I'll have to look at the type-hint-of-host-call logic, if any
10:27	drewr	Ugh. I'm seeing more and more :use without :only. We need a PEP 8 for Clojure.
10:27	rhickey	PEP 8?
10:28	drewr	It's a style guide for Python that the community has rallied around.
10:28	rhickey	link?
10:28	drewr	http://www.python.org/dev/peps/pep-0008/
10:29	drewr	However, he doesn't seem to address "from foo import *" in that document.
10:30	drewr	It's strictly syntactical.
10:31	drewr	He does talk about writing confusing code, which :use could fall under.
10:32	rhickey	Chouser: so, it looks like there is no type hinting of host calls, nor perhaps should there be. They have defined return types. It seems to be a job for cast, just as in Java, but there is no way to convey the type from cast without compiler support, I think
10:32	chouser	I now use :use exclusively, and mix in :as and :only [] as needed to get the results I want.
10:33	stuartsierra	I use (:require ... :as ...) exclusively. Should I be using :use/:as instead?
10:34	drewr	You guys are missing my point. It's the naked use of :use that I'm complaining about.
10:34	rhickey	assigning to a typed local forces the cast, but isn't an option for a free expression
10:34	drewr	Symbols get imported into the local namespace that you have no idea where they came from.
10:34	chouser	rhickey: ok. It's a bit surprising for the type hint to be simply ignored in some cases... any chance we could have a warning when that happens?
10:34	stuartsierra	drewr: I agree.
10:35	rhickey	Chouser: I need to think about it
10:35	chouser	drewr: yes, I know, I just thought I'd mention my usage while we're in the vicinity of the topic. :-)
10:35	drewr	stuartsierra: Compojure does it like it has an addiction. I noticed this morning that incanter does too.
10:35	drewr	chouser: Ah, thanks. :-)
10:35	chouser	drewr: and I absolutely agree. naked :use is Not Good.
10:37	chouser	stuartsierra: :require doesn't let you do :only, which sometimes is a nice feature. And rather than have to shuffle forms between :require and :use as I adjust my usage, I just have one big ol' :us block
10:39	chouser	like the second example here: http://groups.google.com/group/clojure/msg/67f26c65bb1e2127
10:39	drewr	So perhaps something as detailed and pedantic as PEP8 isn't necessary, but maybe a short canonical reference that we can point to as "official" would help.
10:39	drewr	chouser: I remember that. Is that now in 1.0?
10:39	chouser	no, nothing was ever done
10:39	drewr	Ah, well I'm +1 I think.
10:40	chouser	there were a couple alternatives suggestioned in that thread with various amounts of backward-incompatibility
10:40	rhickey	A pep-8-like guide might make a nice page in the contrib wiki, authored by you more experienced folks, and hopefully resulting in at least consistency in contrib
10:41	danlarkin	hear hear!
10:42	rhickey	I volunteer to kibitz :)
10:42	chouser	maybe now that we're post-1.0 we can ditch :require and make :use disallow naked use (have to give an :as, :only, or I suppose :exclude)
10:44	rhickey	that seems a bit draconian
10:44	chouser	:-)
10:45	drewr	:-)
10:45	chouser	It's a bargaining position. Make me an offer!
10:45	rhickey	I offer a wiki page for you guys to provide your best advice
10:46	drewr	I'll gladly contribute.
10:47	chouser	rhickey: but, but ... you didn't move! Are you sure you know how to bargain?
10:47	drewr	Do you have to be a project member to do so?
10:47	drewr	And does the autogeneration of the docs interfere with manually edited pages?
10:47	drewr	Doesn't look like it.
10:48	rhickey	drewr: you do need to be a member
11:17	chouser	wow
11:17	chouser	if you try to return nil from a proxy method has a primitive return type, you get a NullPointerException
11:18	chouser	I suppose that should have been obvious, but I just spent longer than I'd like to admit tracking that NPE down.
11:19	cemerick	yeah, i hit that one once before, too. Not sure what else it could do, though.
11:19	chouser	right
11:22	cemerick	naked :use absolutely has its uses, when you know what you're doing.
11:22	chouser	cemerick: it's not a problem for you. It's a problem for me when I try to read your code.
11:23	cemerick	chouser: well see, that's my point -- I'd never use a naked :use in any ns I'd expose. However, when you control the codebase you're roping in, it's extraordinarily convenient.
11:24	chouser	cemerick: control and know intimitely
11:24	drewr	cemerick: I'm not in favor of banning it outright, but for anything intended to be use by others it really should be avoided.
11:24	drewr	And by "others" I mean you after you've slept. :-)
11:24	chouser	But even I wasn't suggesting banning it ... you'd still be able to say :exclude () if you really wanted to.
11:25	drewr	chouser: Ah, just a little added effort to make it explicit?
11:25	chouser	right, rather than the most succinct default.
11:30	cemerick	didn't the assert form used to take an optional string describing what was being asserted?
11:31	stuartsierra	cemerick: I don't think so. It was requested once.
11:52	chouser	(.schedule timer #(do-thing) 1000)
11:53	chouser	oops, TimerTask is a Runnable, but Runnable is not a TimerTask
11:53	chouser	(.schedule timer (proxy [TimerTask] [] (run [] (do-thing))) (long 1000))
11:53	chouser	sigh
11:54	hiredman	scheduledthreadpoolexecutor
11:54	chouser	hm
12:02	chouser	gah. I guess it's better.
12:03	chouser	it takes both Runnable and Callable, so I have to hint the closure.
12:03	chouser	(.schedule #^ScheduledThreadPoolExecutor e #^Runnable #(prn :hi) (long 500) TimeUnit/MILLISECONDS)
12:04	hiredman	correct
12:04	rhickey	do you need to hint e?
12:05	chouser	actually, that's interesting. If I don't hint e and also don't hint #(), I get a reflection warning but it works at runtime.
12:05	rhickey	right
12:05	chouser	If I hint e, I get a compile-time error unless I also hint #()
12:06	chouser	this is fast-path -- I'd rather hint.
12:07	chouser	this code base is making me wish for centrally-hinted struct-maps (or something similar)
12:10	cemerick	I remember rhickey speculating about a struct-map impl that generated a class that implemented APM, but stored the struct vals as raw java fields. Lots faster for those struct slots, and it'd have a distinct type.
12:11	rhickey	cemerick: we'll see what, if anything, struct-map needs post 'instance'
12:11	cemerick	that's something I plan on implementing eventually, if no one else gets to it before me :-)
12:11	cemerick	I missed almost all of the irc chatter about 'instance', so I'm in the dark. Good luck searching the logs for 'instance', too :-)
12:12	rhickey	Why Clojure over Scala?
12:12	rhickey	I was asked
12:12	stuartsierra	Dynamic types, if that's your thing.
12:12	hiredman	clojurebot: what of scala?
12:12	clojurebot	"you can usually accomplish a lot by laboriously enumerating type arguments everywhere." -- seen in #scala
12:13	technomancy	because "it's better than Java" is not aiming high enough.
12:13	cemerick	technomancy: +1
12:13	technomancy	actually that's more like Groovy
12:13	cemerick	I was going to say, because onerous complexity is bad?
12:13	rhickey	here's what I have so far:
12:13	rhickey	Clojure is really quite simple. It is dynamic. Having fewer paradigms to support, it is more focused on being functional. Being a Lisp, it has a regular syntax, and syntactic extensions are very consistent.
12:14	stuartsierra	good statr
12:15	rhickey	looking for anything missing from the perspective of people who've switched/ used both
12:15	hiredman	for scala being mixed paradigm, the community seems to be obsessed with complex type manipulation, like with haskell, clojure neatly side steps that
12:16	cemerick	rhickey: I'd amend "It is dynamic, but delivers java-native performance."
12:16	rhickey	cemerick: that's covered in another part of the interview
12:16	kotarak	which will be questioned immediately
12:17	cemerick	kotarak: I think that's spot-on. I don't think scala has any unchecked math support at all (or, last I looked), so that's a clear differentiator. Besides that, they're likely on par.
12:19	Chousuke	I think syntactic abstraction is important. the "true" core language is very small, and the tools that are used to build the rest of Clojure are available to programmers as well, not just the language implementers.
12:19	rhickey	Chousuke: I think Scala fans think the same of Scala
12:20	hiredman	yeah, again, in #scala they gripe about the compiler and the emitted bytecode all the time
12:20	gnuvince	cemerick: I'd replace "delivers" with "sometimes delivers" or "may deliver"
12:20	Chousuke	With Clojure, you just get a neat java library for building your own languages. :)
12:21	kotarak	cemerick: ignore me ;) I'm just fed up by all the "perfomance issue" posts. "I have here this ugly, imperative micro-benchmark testing the wrong thing, Why is it too slow?"
12:21	kotarak	I like Clojure's consistency. (swap! an-atom-with-a-map update-in [:foo :bar] conj some-thing)
12:22	cemerick	rhickey: I used scala semi-exclusively for 8 months or so prior to moving to clojure (almost a year ago!). Scala is simply too complex for me, and its core datastructures are (were?) bug-prone and difficult to extend.
12:25	technomancy	it might be worth mentioning that you can read through all of core.clj just a few months after learning Clojure without really getting too confused.
12:25	technomancy	that's not true of very many languages
12:26	stuartsierra	true
12:26	hiredman	cemerick: do the scala collections interop with the java collections easily?
12:28	cemerick	of course, none of this matters. Scala or groovy will likely grow significantly, simply due to people writing Java in (Scala\|Groovy), and enjoying the marginally-better compilers.
12:28	cemerick	hiredman: yes, but last I knew, scala generics don't interop with java generics, so List[Foo] ends up just being List<Object> in java.
12:29	cemerick	presumably, they've fixed that in a year's time.
12:29	stuartsierra	cemerick: that's true of Clojure too, isn't it?
12:30	cemerick	stuartsierra: to a far lesser extend, I suspect. Parens are enough of a distraction to dissuade people long enough to settle for what's comfortable, advantages be damned.
12:30	cemerick	s/extend/extent
12:31	gnuvince	I think he was talking about the generics part
12:31	stuartsierra	yes
12:36	technomancy	stuartsierra: have you seen this? http://github.com/technomancy/clojure-http-client/tree/master
12:36	stuartsierra	no
12:37	technomancy	my fault for not announcing it on the mailing list, but I'm afraid we may have duplicated some effort.
12:38	stuartsierra	No harm, really.
12:39	stuartsierra	I'm aiming in a slightly different direction. I want to make a completely asynchronous client, with all response information mediated through an API.
12:40	stuartsierra	And, eventually, a servlet-wrapper that uses the same API.
12:40	technomancy	yeah, I guess that's not quite the same thing.
12:43	stuartsierra	I'm hoping to build several layers that can be used independently. http/connection.clj is the low-level client API, http/agent.clj is a higher level, then build a synchronous client on top of that.
12:43	technomancy	I could probably adapt my synchronous client to use your connection lib if it's any easier.
12:44	technomancy	oh, you mean build a synchronous client on top of the agent one?
12:44	stuartsierra	That was my thought.
12:44	stuartsierra	Or on top of the low-level lib, it doesn't really matter.
12:46	technomancy	well if you want some help with that just let me know.
12:46	stuartsierra	sure, will do. I just wanted to throw it out there so people could see what I was up to, it may be a couple of weeks before I have time to finish it.
12:48	stuartsierra	I like your url-encode and cookie fns, might borrow those. :-D
12:48	technomancy	no problem.
12:55	technomancy	man... apt-get and java really do not mix, do they...
12:57	stuartsierra	Ubuntu isn't too bad with Java 6
12:58	technomancy	stuartsierra: right, for Java itself it's not bad, but for java libraries it gets wacky
12:58	stuartsierra	oh, yeah, I never use it for that :)
12:58	technomancy	services that don't start automatically, no shell scripts get installed. not a lot of fun to try to guess how it works.
13:01	technomancy	first thing I see out of the box: "HTTP Status 500 - Severe errors in solr configuration"... yeah, I guess it's time to install from source.
13:02	stuartsierra	Or the packaged binaries. Solr's not that hard to configure, but it won't run out-of-the-box.
13:02	technomancy	not even the admin interface? hmm; maybe the instructions I have were out of date.
13:03	stuartsierra	I think you can run the "example" JAR, but nothing else.
13:04	stuartsierra	you can't load new docs without changing the schema.xml
13:04	technomancy	"Severe errors" makes me think it's not just a "you haven't set it up to do anything yet" kind of problem.
13:04	technomancy	but what do I know...
13:05	stuartsierra	It's probably just missing paths for the index, "solr.home", schema, etc.
13:06	technomancy	guess I'm used to debian providing sane defaults for that, but clearly their java packaging is of a different calibre
13:16	technomancy	it was missing a dependency in its listing. rock. on.
13:17	stuartsierra	huh
13:22	rhickey	slides from lightning talk I gave on chunked seqs: http://groups.google.com/group/clojure/web/chunks.pdf
13:23	chouser	rhickey: re: scala -- I don't know if it's fair to mention, but #clojure is a much friendlier place to ask dumb questions than #scala
13:23	rhickey	Chouser: probably not, even if true :)
13:24	rhickey	I'll write up some prose on chunked seqs and move the diagrams to a page on the site
13:25	chouser	also, much more of the "magic" in Clojure is contained. Refs seem magical, but only within dosync blocks; Persistent containers are magical in the properties they provide, but have simple clear behavior.
13:27	chouser	Contrast with scala's implicit conversions, for example, which can lure you into creating implicit magic hidden throughout your code
13:27	rhickey	Chouser: yeah, but tough to convey until you see them in action - for now subsumed by "simpler"
13:28	rhickey	actually I didn't even say simpler, just that Clojure was simple
13:29	chouser	ok
13:30	chouser	I guess if someone gets into scala far enough that the thought occurs to them, "there must be a simpler way..." perhaps that will lead them here.
13:31	rhickey	I'm taking the Clojure over Scala and Clojure over Erlang questions as opportunities to highlight Clojure's strengths rather than direct comparisons
13:31	chouser	I wonder if I could find the comment that brought me here. I think it was by Rich on some blog or other. I think I had Clojure and Qi pages open side-by-side for a while, trying to decide which to dive into next.
13:32	chouser	rhickey: heh, always the high road, eh?
13:32	rhickey	Chouser: It has served us well, IMO
13:32	Cark	chunked seqs : kind of like cdr-coding isn't it ?
13:33	rhickey	Cark: not too much
13:33	rhickey	the structure is sitting there already in the vectors and maps
13:33	Cark	i only see the pdf, do yo mean that one can access the underlying structure from client code ?
13:33	rhickey	its much more about seqs on them than it is about gaming lists
13:33	technomancy	being nice doesn't drive page hits quite as well as a good conflict though, so maybe after this we could set up a fistfight between Rich and Odersky?
13:34	hiredman	technomancy: some kind of concurrent fistfight
13:35	rhickey	Cark: yes, seqs on vectors can leverage the indexed structure they already have
13:36	rhickey	search for Clojure in: http://blog.objectmentor.com/articles/2009/06/05/bay-area-scala-enthusiasts-base-meeting-whats-new-in-scala-2-8
13:36	rhickey	Beyond 2.8
13:37	chouser	nice. gotta love open source.
13:38	chouser	Bagwell's containers aren't Persistent, though, are they?
13:38	rhickey	no
13:41	chouser	cgrand: fantastic. re: http://clj-me.blogspot.com/2009/06/linear-interpolation-and-sorted-map.html
13:42	rhickey	someone finally used subseq!
13:48	cgrand	chouser: thanks
13:57	Chousuke	heh, I had forgotten subseq exists.
13:57	Chousuke	judging from its docstring, it's pretty old.
13:57	Chousuke	(test (.. sc comparator (compare ek key)) 0) --- ???
13:58	Chousuke	wouldn't that be (sc ek key) nowadays :/
14:00	Chousuke	wait, I forgot the actual test. hmm.
14:29	cemerick	I keep meaning to apply that sorted-set-by patch to my local clojure -- then subseq would be very useful.
14:42	cgrand	cemerick: +1
14:42	mrsolo	little schemer, is it a good book?
14:42	technomancy	mrsolo: yes!
14:43	technomancy	very good.
14:43	mrsolo	ok
14:43	mrsolo	is it only for beginners?
14:43	hoeck	cemerick: +1, waiting for (official) sortet-set-by to
14:43	technomancy	mrsolo: not at all
14:43	technomancy	unless you define "beginner" as "haven't implemented a language yet" =)
14:43	hoeck	r/to/too
14:43	mrsolo	great
14:43	mrsolo	buy :-)
14:44	cemerick	hoeck: there's a patch out there already. I haven't looked at it, but regardless, it's not a complicated change at all.
14:44	mrsolo	how but the next two in the series?
14:44	gnuvince	mrsolo: it starts easy, but then at the end you're into CPS
14:44	gnuvince	Ditto
14:44	gnuvince	I have way too many books on my shelf
14:45	mrsolo	nice... CPS is that oftenly used at all? it got mentioned from time to time
14:45	gnuvince	I haven't seen it used very often, but I don't know if that's because programmers don't know about it or because there are better alternatives.
14:47	Hun	the problem with cps is that you cannot use it in just part of your system
15:00	lisppaste8	cemerick pasted "key-paths -- is this available anywhere else already? I (unfortunately) implemented it before looking..." at http://paste.lisp.org/display/81548
15:07	hiredman	~scala is also<reply>"we are completely screwed on ==." -- seen in #scala
15:07	clojurebot	Alles klar
15:08	cemerick	heh, was that recent?
15:08	hiredman	minutes ago
15:08	cemerick	I've long since stopped lurking on #scala
15:09	mib_dgk9yuyc	Is there a function to split a vector on the last item that matches a predicate? eg: (x [1 6 3 7 2] #(> 5 %1)) -> ([1 6 3] 7 [2])
15:15	mib_dgk9yuyc	Ok, here's an easier one - is there a better way to invert a predicate than #(not (pred %1))?
15:16	stuartsierra	(complement pred)
15:16	mib_dgk9yuyc	thanks. I was searching for "inverse".
15:17	mib_dgk9yuyc	I'm also looking for something like "index-of" - the index of an item in a vector that matches a predicate. Is there a built in function for that?
15:18	stuartsierra	check clojure.contrib.seq-utils.
15:18	tgevaert	you could use (first (filter pred seq))
15:19	lisppaste8	cemerick pasted "is-one-of? impl e.g. (is-one-of? String Integer Object) => true" at http://paste.lisp.org/display/81550
15:19	tgevaert	oops. that wouldn't return the index. nvm
15:19	mib_dgk9yuyc	ok, I'll look at contrib. I've been trying to learn the built-in stuff first, to avoid overloading my brain
15:20	hiredman	that would need a linear search anyway
15:20	chouser	I avoid using indexes whenever possible.
15:20	mib_dgk9yuyc	yeah, I get the feeling that looking for an index is a remenant of a non-functional mindset
15:21	kotarak	Getting rid of loops iterating through the index most of the time also gets rid of the index itself...
15:21	mib_dgk9yuyc	what I really want is to split into (part-before-the-match, matching-item, part-after-the-match), given a seqence and a predicate
15:22	stuartsierra	Ah, you want a slightly modified "partition".
15:22	mib_dgk9yuyc	Python's str.partition is my mental model for what I want
15:23	chouser	,(split-with #(not= % 5) (range 10))
15:23	clojurebot	[(0 1 2 3 4) (5 6 7 8 9)]
15:23	chouser	almost but not quite...
15:23	hiredman	he seems to want vectors
15:23	stuartsierra	Try c.c.seq-utils/partition-by
15:29	stuartsierra	,(clojure.contrib.seq-utils/partition-by #(not= 5 %) (range 10))
15:29	clojurebot	java.lang.ClassNotFoundException: clojure.contrib.seq-utils
15:29	stuartsierra	,(require 'clojure.contrib.seq-utils)
15:29	clojurebot	nil
15:29	stuartsierra	,(clojure.contrib.seq-utils/partition-by #(not= 5 %) (range 10))
15:29	clojurebot	((0 1 2 3 4) (5) (6 7 8 9))
15:30	lisppaste8	kotarak pasted "py-partition w/ loop, some better way?" at http://paste.lisp.org/display/81551
15:30	kotarak	stuartsierra: what happens with two 5's?
15:31	kotarak	is that desired?
15:31	chouser	cemerick: I'm pretty sure you don't need lazy-seq in your key-paths. mapcat's already sufficiently lazy.
15:31	stuartsierra	,(clojure.contrib.seq-utils/partition-by #(not= 5 %) [1 2 3 5 5 7 8 9 5 9 10])
15:31	clojurebot	((1 2 3) (5 5) (7 8 9) (5) (9 10))
15:31	cemerick	chouser: good point, thanks :-)
15:31	kotarak	mib_dgk9yuyc: How the above case defined?
15:32	tunde	Hello #clojure!
15:34	Hun	hello world!
15:34	chouser	cemerick: there's a bunch of tree stuff I hardly ever use, but I don't think any of it can do what you're doing.
15:35	chouser	...short of a new zip type, which I think would end up being clumsy compared to what you've got.
15:35	hiredman	huh
15:36	chouser	"bunch" meaning: clojure.zip, tree-seq, contrib.walk
15:36	cemerick	yeah, I mucked with tree-seq for a bit before tossing off key-paths
15:37	cemerick	I think I could have made it work, but it probably would have required a two-step process.
15:44	chouser	(map first (tree-seq #(map? (% 1)) #(for [[k v] (% 1)] [(conj (% 0) k) v]) [[] m]))
15:45	chouser	cemerick: so tree-seq can do it, but that doesn't mean it's better than what you've already got
15:46	cemerick	ah, I didn't think of doing it that way
15:48	mib_dgk9yuyc	is colojure-contrib only available through svn? there is nothing on the downloads page.
15:50	technomancy	mib_dgk9yuyc: yeah, you'll need to get it from source. there hasn't been an official release.
15:51	mib_dgk9yuyc	ok, so everyone works on the bleeding edge, I see - there are no tags, no stable version...?
15:51	chouser	it doesn't bleed very much
15:51	mib_dgk9yuyc	maybe you're not stabbing hard enough
15:51	mib_dgk9yuyc	:)
15:51	chouser	we "ought" to have a release that works with clojure 1.0.0, but nobody's done ityet.
15:52	asdfasfe	is clojure 1.0 out yet?
15:52	dnolen	yes
15:52	technomancy	mib_dgk9yuyc: that's part of the design of contrib; it's much looser than Clojure itself in terms of what goes in.
15:52	technomancy	but I agree that releasing a Contrib 1.0 would be wise
15:53	ajuc	hello, I have stupid question
15:53	ajuc	clojure is my first lisp so don't kill me
15:53	ajuc	why this doesn't print anything : http://pastebin.com/m6a7a4bed
15:54	hiredman	I think you want when not while
15:54	gnuvince	ajuc: defn defines a function. You need to call it.
15:54	chouser	ajuc: It's probably just not flushing stdout
15:54	technomancy	ajuc: standard out doesn't flush unless a newline gets printed or you call flush
15:54	hiredman	chouser: oh
15:54	chouser	ajuc: try 'println' instead of 'pr'
15:55	ajuc	ah :)
15:55	ajuc	ok, thanks
15:55	chouser	or 'prn' if you actually mean to be printing objects and not just strings.
15:55	ajuc	it's only test
15:55	ajuc	but I've thought I don't understand something fundamental
15:56	hiredman	(doc while)
15:56	clojurebot	"([test & body]); Repeatedly executes body while test expression is true. Presumes some side-effect will cause test to become false/nil. Returns nil"
15:57	hiredman	so that code as the equiv of a while(true){} loop in it
15:57	ajuc	yes, I wanted that to test some threading
15:58	ajuc	now it works
16:11	mib_dgk9yuyc	,(first [1 2 3])
16:11	clojurebot	1
16:11	mib_dgk9yuyc	cool
16:11	mib_dgk9yuyc	just testing
16:11	mib_dgk9yuyc	clojurebot really is a bot
16:12	hiredman	clojurebot: are you a bot?
16:12	clojurebot	No entiendo
16:12	technomancy	yeah, hiredman hasn't added in the turing test module yet
16:12	hiredman	clojurebot: are you a computer program?
16:12	clojurebot	No entiendo
16:12	hiredman	hmmm
16:13	tgevaert	how does it avoid running infinite loops?
16:13	hiredman	with style and grace
16:13	mib_dgk9yuyc	why does clojurebot respond to ",(" instead of "~(" - this ain't common lisp!
16:13	technomancy	~ is used for something else IIRC
16:13	clojurebot	for is not a loop
16:14	kotarak	mib_dgk9yuyc: clojure is not common lisp...
16:15	hiredman	mib_dgk9yuyc: , is whitespace, so it is nice for copy&paste stuff around
16:18	chouser	,,,,,,,,5
16:18	clojurebot	5
16:24	dnolen	interesting, Grand Central Dispatch in the next version of OS X reminds me of agents (Objective-C/C++/C on OS X will support anonymous functions and closures), http://images.apple.com/macosx/technology/docs/GrandCentral_TB_brief_20090608.pdf, curious to see what the concurrency Clojure gurus think of this. it's a slightly different approach to a lockless design than Clojure.
16:32	stuhood	hm... sounds like a threadpool
16:33	chouser	but outside the application? I wonder if there are security implications.
16:34	chouser	"simple extension to C" ...sigh.
16:34	technomancy	tee hee
16:37	chouser	huh. Doesn't look like they address state management at all. I wonder how it can help you avoid locks.
16:37	stuhood	being able to schedule based on io/timers looks handy though
16:38	chouser	I guess if any given piece of state is only changed via one particular queue, that can help.
16:39	chouser	oh, I guess they say that in "private queues" Not sure how that's easier than a lock, and it doesn't adderss the "hard" problems that clojure refs do.
16:42	stuhood	ah... yea, so the private queue is kindof like an agent
16:49	Chousuke	gcd sounds neat. Having the system manage a global thread pool for applications does sound simpler than each program managing its own threads.
16:51	Chousuke	at least, from the application's point of view :P
16:56	mib_dgk9yuyc	Is there some trick to using clojure-contrib that I should know about? (require 'clojure.contrib.seq-utils) doesn't work (FileNotFoundException)
16:56	mib_dgk9yuyc	I added clojure-contrib.jar to my classpath
16:56	mib_dgk9yuyc	and C:/clojure-contrib/src too
16:59	Chousuke	that ought to work.
16:59	technomancy	mib_dgk9yuyc: you didn't use add-classpath, did you?
17:00	mib_dgk9yuyc	no, didn't know about add-classpath
17:00	kotarak	mib_dgk9yuyc: then forget it again, as fast as you can. ;)
17:00	mib_dgk9yuyc	forget what? ;)
17:00	technomancy	mib_dgk9yuyc: so you restarted your JVM after changing the classpath?
17:00	duck1123	exactly
17:01	mib_dgk9yuyc	yes
17:01	mib_dgk9yuyc	should I be putting clojure-contrib.jar on the classpath, or the src directory, or both?
17:02	Chousuke	should work with either. :/
17:02	technomancy	mib_dgk9yuyc: the jar is probably better
17:02	technomancy	mib_dgk9yuyc: maybe if you spelled out your exact steps?
17:05	mib_dgk9yuyc	C:\clojure>set CLASSPATH=C:\clojure-contrib\clojure-contrib.jar;%CLASSPATH%
17:05	mib_dgk9yuyc	C:\clojure>java -jar clojure-1.0.0.jar
17:05	mib_dgk9yuyc	user=> (require 'clojure.contrib.seq-utils)
17:05	technomancy	mib_dgk9yuyc: oh, if you use the -jar option, it ignores your CLASSPATH
17:05	kotarak	meep -jar
17:05	technomancy	woo! yay JVM!
17:06	mib_dgk9yuyc	oh, ok. so how do I run the repl?
17:06	technomancy	mib_dgk9yuyc: just put clojure.jar on the classpath and call: java clojure.main
17:06	technomancy	the JVM has a lot going for it, but I've yet to see a platform with a worse command-line interface.
17:07	mib_dgk9yuyc	victory!
17:07	mib_dgk9yuyc	thanks
17:07	chouser	mib_dgk9yuyc: now go find who told you to use -jar and give them a stern talking-to.
17:08	mib_dgk9yuyc	one more noob question: is (System/exit 0) the normal way to get out of the repl?
17:08	chouser	mib_dgk9yuyc: try Ctrl-Z <Enter>
17:08	technomancy	chouser: then find the guys who implemented it and smack them around too for good measure!
17:08	chouser	technomancy: you must not be on Windows.
17:09	technomancy	oh, yes. that would be true.
17:09	duck1123	doesn't C-c also work?
17:10	kotarak	C-c is so hard and unfriendly to the process....
17:11	duck1123	ahh... so C-d shuts things down properly?
17:11	Chousuke	it just closes the input stream :p
17:11	kotarak	duck1123: C-d means "end of input".
17:11	Chousuke	most programs quit at that point :)
17:11	kotarak	yeah
17:11	Chousuke	but it might hang if you have a thread running.
17:12	kotarak	C-c is more like being thrown of the bus by the driver pointing a gun at you at the terminal station.
17:12	duck1123	actually, I've been using "mvn jetty:run" lately to start my server, so I have no choice but use C-c
17:22	duck1123	so is there a way to make it so that the return values in the slime repl are pretty printed?
17:27	replaca	duck1123: I think there is, but I've never really tried to do it
17:28	replaca	duck1123: you should be able to set your repl's print function to pprint
17:28	replaca	duck1123: it's hard for me to do, since I'm often debugging the pretty printer :-)
17:29	replaca	oh, yeah, now that I think of it, slime may add a layer of indirection that would mess you up/help you
17:30	duck1123	I'm pretty sure it does
17:30	duck1123	the slime repl isn't an actual clojure repl AFAIK
17:30	replaca	dnolen added the stuff that let macroexpansion pretty print, maybe he knows
17:32	dnolen_	heh, I just wanted slime to macroexpand properly, I never bothered with pretty printing repl output, and i'm no slime expert beyond how to use it ;)
17:33	replaca	I just always type (pp) to the repl, but that is not wholly satisfying
17:35	duck1123	cool, I didn't know about (pp) that'll be good enough I guess
17:36	dnolen_	(pprint some-expr), after you've run (use 'clojure.contrib.pprint)
17:38	duck1123	that's what I had been doing, and actually (pp) works fine. I don't want all of my output pretty printed, just the ones that are hard to read
17:38	technomancy	the main advantage of vimclojure over slime is that its author still uses it. =)
17:38	kotarak	technomancy: hehe :)
17:39	kotarak	SLIME is certainly more advanced for Lisp in general, but VC does a good job for Clojure too. :)
17:41	duck1123	is there an easy way to convert a hash-map into a struct? (assuming I already have the struct set up)
17:41	kotarak	... considering Vim's interprocess limitations, anyway.
17:42	kotarak	(into (struct-map foo) my-hash-map) ?
17:46	duck1123	what I have is a vec of hash-maps that I'm turning into a vec of structs. Your code will return a struct of the first value, but if I try to do it in a map, I get an error
17:47	replaca	(pp) is really just (pprint *1) for the typing impaired (like me!)
17:47	duck1123	I would rather just get the structs back from the mysql server directly, but this is what clj-record gives mme
17:49	duck1123	ok, i got it working no
17:57	technomancy	oh man. contrib's prxml is a lot nicer than clojure.xml.
17:59	duck1123	I'm still waiting for a good namespace-aware xml lib for clojure
18:00	technomancy	nobody uses namespaces anyway
18:00	clojurebot	namespaces are (more or less, Chouser) java packages. they look like foo.bar; and corresponde to a directory foo/ containg a file bar.clj in your classpath. the namespace declaration in bar.clj would like like (ns foo.bar). Do not try to use single segment namespaces. a single segment namespace is a namespace without a period in it
18:01	technomancy	oh, I'm sorry, I misspelled understands.
18:02	duck1123	there are some times when you absolutely need ns-support
18:02	technomancy	yeah, I'm just kidding.
18:02	technomancy	life's a lot nicer if you don't though. =)
18:06	mrsolo	is there another way to do this? (apply (partial format "%s%s") (map identity '("one" "two")))
18:07	mrsolo	identity is not real function of course.. so is list one, two...
18:08	kotarak	(apply format "%s%s" (map f [1 2 3]))
18:08	kotarak	oops.
18:08	kotarak	-3
18:41	mrsolo	is there a fucntion that does this? :foo -> "foo"?
18:41	dreish	,(name :foo)
18:41	clojurebot	"foo"
18:41	mrsolo	ty
18:52	mib_t2h1qb	,(dorun (repeat 1))
18:52	clojurebot	Execution Timed Out
20:58	emacsen	Is the JavaOne video available anywhere?
20:58	emacsen	(was there video?)
22:06	duck1123	I so wish I could have gone to JavaOne
22:23	mrsolo	is there a fucntion that does this? (foo println) => "println"
22:24	Cark	,(name 'println)
22:24	clojurebot	"println"
22:24	Cark	would that do ?
22:24	mrsolo	no quote
22:25	Cark	you might want to use a macro then
23:09	slava	my copy of programming clojure arrived today :)
23:10	cataska	slava: great !!