#clojure – 2012-01-02

2012-01-02

00:00	technomancy	it means unless you want to go through a bunch of grunt work by hand you're limited to using clojure and no external libraries
00:01	bitops	technomancy: I may be misremembering, but I thought I had read that contrib was bundled with the clojure jar?
00:01	technomancy	no, contrib has been split up into a bunch of separate jars now
00:01	bitops	right, I saw that from the link(s) above
00:02	bitops	it's not an issue for me, I'm just trying to figure out what is the right way to get started and set up :)
00:03	graphbum	since I am in the midst of shifting from 1.2 to 1.3, I saw the contrib modularization. so you need to grab numeric tower
00:03	bitops	ah okay
00:03	graphbum	you can do that a number of ways....
00:04	bitops	I'll go out on a limb and assume leiningen is the easiest way?
00:04	graphbum	that's what technomancy was saying
00:04	amalloy	clojurebot: leiningen is always the easiest way
00:04	clojurebot	Ack. Ack.
00:04	bitops	if the right thing to do is having a "playground" project I'm all for that
00:04	amalloy	bitops: yes, sounds good
00:05	bitops	that's sort of interesting, making the standard library a dependency you have to download. not knocking it by any means, just observing…could have useful applications
00:05	graphbum	so you'd like.... "lein new playground" somewhere
00:05	bitops	graphbum: what if I have some existing files I want to leiningenify?
00:06	graphbum	lein will make the structure for you and populate it with some stuff, namely a project.clj I believe
00:06	graphbum	you can dump whatever you want in there
00:06	graphbum	in the directory
00:06	bitops	ah, just tried it. pretty painless
00:07	graphbum	you set dependencies inside project.clj
00:07	technomancy	it's not really the standard library
00:07	bitops	well geez, when's the pain going to start?! I was expecting a yak to show up any old time now.
00:07	bitops	:P
00:07	technomancy	the standard library is just clojure.set/xml/zip/test/etc that comes with the jar
00:07	amalloy	right. the standard library is the stuff that does come with clojure. functions like map, filter, reduce
00:09	graphbum	there's some really useful shit in contrib though...
00:09	graphbum	useful for me at least
00:10	amalloy	there's some really useful stuff in ring too, but that doesn't make it part of the clojure stdlib
00:13	graphbum	right....except some of that really useful shit from contrib did become part of the standard lib....because it was useful
00:14	bitops	technomancy: I hate to sound like a broken record, but how do I know which version of numeric-tower to import? https://github.com/clojure/math.numeric-tower isn't much help. :(
00:14	technomancy	bitops: I usually try http://search.maven.org
00:16	bitops	technomancy: cool…I found it….but then what to type in the project.clj file? I'm sorry if that's a stupid question, it's not totally clear to me how it maps onto the Maven abstraction.
00:16	technomancy	if you do "lein help tutorial" it should have you covered
00:16	technomancy	you can skim to the part about adding deps, but at some point you should read the whole thing
00:17	bitops	technomancy: ah okay, thank you, I'll do that
00:17	bitops	thanks for all the help! much appreciated :)
00:17	technomancy	sure
00:50	graphbum	did the old repl-utils from clojure.contrib make it into the new modular stuff under 1.3?
00:50	graphbum	trying to grab what used to be clojure.contrib.repl-utils/show
00:52	amalloy	clojure.reflect/reflect
00:52	graphbum	nice, thanks.
01:26	graphbum	wow...i did not realize how disruptive 1.3 would be against 1.2 projects I had
02:14	replaca	technomancy: still around?
04:14	tomoj	is there a better way than @(promise) to cause a thread to just do nothing
04:20	amalloy	(.wait (Object.))?
04:31	tomoj	I just get an IllegalMonitorStateException
04:38	woodz	You need to be in a Java 'synchronized' block to acquire an object's monitor and be able to .wait on it. Clojure provides access to this via the 'locking' macro, which has the advantage of releasing the monitor when the enclosed body of code finishes.
04:40	tomoj	so (let [o (Object.)] (locking o (.wait o))) ?
04:41	amalloy	well @(promise) has got to be better than that
04:41	Fossi	:D
04:41	woodz	Yes, except that that particular snippet will tie up whichever thread executes it, probably infinitely, as the new Object isn't available for another thread to signal
04:41	amalloy	woodz: that was the point
04:41	tomoj	that's the goal
04:42	woodz	I joined the conversation a bit late, so missed that bit :-)
04:42	tomoj	if the thread dies, it will be reborn elsewhere automatically
04:42	woodz	ok
04:42	amalloy	fwiw, @(promise) probably requires a bit more resources from the jvm than the .wait approach, but since what you're doing is killing off the thread i doubt it matters
04:44	amalloy	&(doc monitor-enter)
04:44	lazybot	⇒ "Special: monitor-enter; Synchronization primitive that should be avoided\n in user code. Use the 'locking' macro."
04:44	amalloy	super-efficient! you can refuse to include the monitor-exit that (locking) would introduce :)
04:45	amalloy	saving 100% (and also 0%) of the cpu cycles that would be spent on that
04:48	wiseen	https://github.com/wiseen/core.observable - I wrote a .NET RX event handling library for clojure/clojurescript
07:31	rangen	why this says 'unable to find resource'? lein install org.clojars.gjahad/debug-repl "0.3.1" it should work right? http://clojars.org/org.clojars.gjahad/debug-repl refers to this info
07:32	rangen	full error: [INFO] Unable to find resource 'org.clojars.gjahad:debug-repl:jar:0.3.1' in repository central (http://repo1.maven.org/maven2). it seems lein does not go to look for clojars repository in this case
07:35	holo	hello
07:35	holo	can someone tell me a very simple case of use (actually useful) for "let" form?
07:41	Chousuke	uhh... any time you want a local variable?
07:41	Chousuke	which is not that uncommon
07:42	Chousuke	or do you use only global variables and literals in your programs? :P
07:46	Chousuke	holo: let can also be used to create closures eg. (defn make-counter-fn (let [foo (atom 0)] (fn [] (swap! inc foo)))) <- now you can call the function returned by make-counter-fn and it will return the number of times it has been called.
07:47	Chousuke	though I guess that's a toy example, it's pretty common in actual code. it's just difficult to come up with good examples without actually having some sort of purpose in mind :P
07:47	Chousuke	I mean closures are common, not counters. :P
07:57	holo	chousuke, I see. I am familiar with closures. I don't use globals or locals yet or anything at all in clojure. I'm just learning clojure from a tutorial
08:00	Chousuke	I'm sure you'll find lots of uses for let once you start writing code, then
08:02	Fossi	for me the most common occurrence is: (let [foo (some-"expensive"-calculation bar baz)] (dothis foo) (dothat foo))
08:03	Fossi	and expensive can also be hard/annoying to write twice ;)
08:05	Fossi	hmm i guess: (let [foo (some-"expensive"-calculation bar baz) quux (some-transformation)] (dothis quux) (dothat foo)) is even used more often :)
08:05	Fossi	as in saving something for later
08:09	holo	Fossi, at the second example there is no reutilization of results
08:11	holo	OK, I guess its cleaner and there is an implicit "do" by using let
08:13	Fossi	ups
08:14	Fossi	i meant to write (some-transformation foo)
08:18	holo	I see, but for a language which returns an expression by being functional looks to have a strong imperative flavour
08:19	Fossi	well, let isnt needed if your code is purely functional
08:19	Fossi	other than saving you lots of typing
08:20	Fossi	oh, and save computation
08:20	Fossi	but not strictly needed, no
08:20	raek	if the value of one expression is needed in multiple expressions, you still need let in purely functional code
08:21	Fossi	you can recompute it then
08:22	raek	holo: why does Clojure look to have a strong imperative flavour?
08:23	Fossi	i think "let" does
08:24	holo	raek, when, do, loop (something more I may forget) forms are purpposely imperative. anyway this is just from the tutorial I am reading. it's not bad to have imperative constructs.. I mean, it just looks as if that is the idiomatic way of doing things. ultimately what matters is choice not to do it
08:25	antares_	hi. I have the following code with gen-class and no matter what I do, the compiler tells me there is no "state" field on the generated class: https://gist.github.com/3fd54c45bce5cdf9e345 — what am I missing?
08:27	holo	in caml, let in the toplevel would create global variables. if used inside something like those examples from Rossi, it would create local variables
08:29	raek	I think of the implicit do like this: what should (let [...] a b c) mean? (let [...] (do a b c)) is a fairly "natural" interpretation.
08:33	Fossi	raek: well, you could disallow that
09:29	nickik	I want to reset up my emacs. Witch is the best current tutorial to get emacs/Starter Kid/Clojre Mode/slime/swank working?
09:45	CrazyWoods	how to use clojure to start a GUI project?
09:46	vimja	nickik: i used http://data-sorcery.org/2009/12/20/getting-started/ to get started
09:46	benoyst	nickik: I've also found this one interesting: http://postposttechnical.com/2011/11/first-steps-with-clojure/
09:51	benoyst	CrazyWoods: I've read a very exciting article a few days ago: http://blog.darevay.com/2011/12/a-seesaw-tutorial/
09:51	benoyst	Hope this helps.
09:53	CrazyWoods	benoyst, thank you
09:53	Fossi	that looks almost nice :)
09:54	benoyst	indeed
10:01	Fossi	does anyone know a tutorial on debugging java via emacs/swank? does that even work?
10:14	zilti	Does someone here use SQLKorma? What type does exec return for a select query?
10:35	bhenry	is there a way to use binding on something qualified as alias/var where alias is the last part of (require '[namespace :as alias])
10:38	Raynes	bhenry: If I understand your question right, then there is nothing stopping you.
10:47	lypanov	if i use someones library that has a line saying (def vm-session-type "gui")
10:47	lypanov	how can i change the value for my usage of the library?
10:47	lypanov	i assume thats what its for..
10:49	bhenry	lypanov: &&(doc binding)
10:57	zilti	Now that's a strange error: "IllegalAccessException Class clojure.lang.Reflector can not access a member of class lyrionch.util.Whirlpool with modifiers "public static final"" Why can't it access something marked public?
10:58	skelternet	is it accessing it for write?
10:59	skelternet	oh…Reflector
10:59	zilti	I'm playing around in the repl and did a (def digest (Whirlpool/DIGESTBYTES))
11:01	zilti	Any other try to access the class results in a "IllegalAccessError tried to access class lyrionch.util.Whirlpool from class lyrionch.models.usersys$eval699 lyrionch.models.usersys/eval699 (NO_SOURCE_FILE:51)" like error.
11:02	raek	zilti: what is DIGESTBYTES? a method or a field?
11:02	zilti	A static field
11:02	raek	then you should do this: (def digest Whirlpool/DIGESTBYTES)
11:03	raek	the extra parens means method call
11:03	zilti	Hmm thanks. But I get the same error again: IllegalAccessException Class clojure.lang.Reflector can not access a member of class lyrionch.util.Whirlpool with modifiers "public static final"
11:08	lynaghk	Has anyone defined multimethods in ClojureScript before? I'm having some namespace troubles excluding clojure.core/+
11:08	lynaghk	https://gist.github.com/1551222
11:13	zilti	Pro-tip: Declare a class as "public" if you want to access it from another namespace...
11:16	yoklov	is there any slowdown associated with metadata
11:17	yoklov	actually no nevermind it'll still be way faster than the numerical calculations I'm doing.
11:21	zilti	I have a Java class and I have a Clojure function accessing that class. Now I want to ensure that only one "instance" of the Clojure function is allowed to access the Java class at a time, forcing other instances to wait (because that Java class isn't thread save). What's the best way to achieve this?
11:32	chouser	pods, if only they existed.
11:42	TimMc	chouser: pods? A web search didn't reveal anything.
11:43	chouser	yeah, they don't exist
11:43	lynaghk	It's a planned construct that Rich talked about at the Conj
11:43	chouser	http://kotka.de/blog/2010/12/What_are_Pods.html
11:43	TimMc	Ah, got it. I took it to be something that existed in some other language.
11:48	zilti	That's a pity... But how should I do it? I'm quite new to concurrency, especially in Clojure
11:51	TimMc	zilti: It's a single instance that you need to coordinate access to from multiple Clojure threads?
11:51	TimMc	Maybe you could send thunks to an agent that controls the instance.
11:52	cemerick	That, or there's always `locking`. :-P
11:52	TimMc	Point.
11:53	raek	(def foo-lock (Object.)) (defn foo [...] (locking foo-lock ...))
11:53	zilti	But wouldn't locking refuse the attempt to access the class? What I need is basically that the whole body of the function that accesses the java class is executed "atomically" so that there can't be a second call to the same function at the same time.
11:54	zilti	So I had something like a "queue" in mind that just puts the other threads trying to access in a "sleep" state
11:54	TimMc	zilti: locking pauses the thread
11:55	zilti	Ok, then I'll do locking
11:55	raek	zilti: have you checked you java.util.concurrent.BlockingQueue?
11:55	raek	http://docs.oracle.com/javase/6/docs/api/java/util/concurrent/BlockingQueue.html
11:55	raek	*checked out
11:55	TimMc	If you just need to send actions, an agent would be good. But if you need to read and write, locking is probably the best.
11:56	zilti	Yes, I'll use locking. I just thought locking would "cancel" a request made at the same time, but if it's pausing the concurrent thread it's ok
11:57	jodaro`	so i'm messing around with aleph/lamina/gloss stuff
11:57	jodaro`	using tcp-client to interact with a server that uses a binary protocol
11:57	jodaro`	i've specified a frame to handle the request
11:57	cemerick	zilti: `locking` uses a Java monitor, just like `synchronized`.
11:58	jodaro`	enqueue it on the connection
11:58	jodaro`	and receive-all the response
11:58	jodaro`	everything appears to work correctly but i'm noticing that my respone is also being decoded using said frame
11:58	jodaro`	which happens to work, but what if i wanted to use a different codec for the response
12:00	jodaro	oh
12:00	jodaro	looks like i can specify an encoder and decoder
12:04	dbushenko	hi all!
12:04	dbushenko	what's the ultimate mongodb clojar?
12:08	solussd	when using clojure.xml/emit to print xml it turns all of my numbers and booleans in the :attrs map into strings, so when I read it back in using clojure.xml/parse, I have nothing but strings for my :attrs. What is the most straightforward way to detect, and convert into the appropriate type, these attributes?
12:11	cemerick	solussd: XML is textual; there's no reason to expect it to natively round-trip other data types.
12:12	cemerick	You could speculatively parse attributes using clojure.walk
12:14	solussd	cemerick: hm. too bad clojure.xml/parse can't be fed a schema
12:16	cemerick	solussd: schemas aren't supported in the JDK IIRC.
12:17	cemerick	OK, so that's wrong.
12:17	cemerick	I should say, I think schemas can only be used to validate.
12:40	solussd	how do you list all of the interfsaces/protocols a type implements?
12:47	Scorchin	I currently have a return value which looks like: (["h1. " "h1" ""]). To get the second element from the sequence, I'm doing the following: (second (first (["h1. " "h1" ""]))). Is there a better way to do the above?
12:49	yoklov	Scorchin: if it's in a let or a function you could use destructuring
12:50	Scorchin	yoklov: thanks, I'll check that out
12:56	yoklov	Scorchin: something like this ##(let [[[fst snd trd]] (list (vector "h1. " "h1" ""))] snd)
12:56	lazybot	⇒ "h1"
12:57	yoklov	though, thats still somewhat awkward.
13:02	flashingpumpkin	hey guys. I'm curious if someone can quickly help me out. I'm running into java interop problems. I'm following this tutorial, but fail to init a new mesh. (Scroll down to the rendering a triangle bit) - http://code.google.com/p/libgdx/wiki/MyFirstTriangle and the ctor error: http://dpaste.com/680334/
13:05	Chousuke	flashingpumpkin: that sort of stuff usually happens when there are multiple similar constructors
13:06	Chousuke	flashingpumpkin: try typehinting the vertex argument, or force the integer literals to be ints with (int 3)
13:06	flashingpumpkin	Chousuke, there are indeed multiple constructors. But, I'm just rewriting the Java example (that works) into Clojure.
13:06	flashingpumpkin	Chousuke, ok, trying :)
13:08	yoklov	that ctor has varargs in java, does that mean anything for the clojure interop/
13:09	flashingpumpkin	Chousuke, nope. Both does not work. Here's maybe more context for the Mesh constructors: https://gist.github.com/153d4bc319da0b0f9efd
13:09	yoklov	try putting the vertex in an array
13:10	yoklov	(to-array [vertex]) maybe?
13:11	flashingpumpkin	yoklov, nope
13:11	Chousuke	looks like it should work if you typehint the vertex
13:11	Chousuke	did you try typehinting it and forcing the 3s to ints at the same time?
13:12	flashingpumpkin	Chousuke, yes
13:12	flashingpumpkin	(to-array [^VertexAttribute vertex])
13:14	flashingpumpkin	I had no idea there is such a thing as varargs in java.
13:14	yoklov	Err, I don't really know what I'm talking about so its totally possible that putting it in an array is the wrong thing to do.
13:15	jodaro	ok, another gloss question
13:16	jodaro	if i have something like
13:16	jodaro	foo\0bar\0baz
13:17	jodaro	is (repeated (string :utf-8 :delimiters ["\0
13:17	jodaro	"]))
13:17	jodaro	the right way?
13:20	TimMc	I guess try it out?
13:20	jodaro	yeah
13:20	jodaro	its the 4 part of the protocol
13:20	TimMc	My only question would be whether there is a final delimiter. I guess there has to be.
13:20	jodaro	fourth part of a response, actually
13:21	yoklov	What's the difference between typehinting with #^type and ^type?
13:22	amro	is there a way to get more information out of "No value supplied for key: true"?
13:22	TimMc	yoklov: The latter is deprecated.
13:22	yoklov	otherwise they're the same?
13:22	clojurebot	I don't understand.
13:23	TimMc	amro: Are you trying to build a map?
13:23	TimMc	I mean, what is the context?
13:23	mattmitchell	jodaro: in your example, what is "string" ?
13:24	clj_newb	this is an honest question; not an attempt at a flame war: I was reading about attmepts of clojure on llvm; and then all tend to mention that the llvm is bad at JIT ... this confuses me, what exactly does the JVM JIT do that the LLVM JIT does not do?
13:24	TimMc	yoklov: Wait, maybe it's the other way around...
13:24	clj_newb	(I was under the impression taht LLVM = the uber JIT, using the latest + best in research tech)
13:25	amro	TimMc: I was passing stuff to a lib, and wasn't sure how it was building a map out of it. was wondering if there's a way to get a representation of the map for debug, at the error
13:25	TimMc	yoklov: Right, ^ is the correct form.
13:25	amro	I fixed it since, but I'd still like to know for future reference
13:28	TimMc	&{:a 1 :b}
13:28	lazybot	java.lang.RuntimeException: Map literal must contain an even number of forms
13:28	jodaro	mattmitchell: its part of gloss
13:28	TimMc	So, not that error...
13:28	jodaro	https://github.com/ztellman/gloss/wiki/Introduction
13:28	TimMc	&(hahs-map :a 1 :b)
13:28	lazybot	java.lang.RuntimeException: Unable to resolve symbol: hahs-map in this context
13:28	TimMc	&(hash-map :a 1 :b)
13:28	lazybot	java.lang.IllegalArgumentException: No value supplied for key: :b
13:28	TimMc	amro: ^ that's what was happening in the lib.
13:28	lypanov	clj_newb: many people don't have much of a clue about it :)
13:29	lypanov	clj_newb: but using llvm would be a huge amount of work. it'd require custom optimization passes
13:29	lypanov	the JVM does a crazy amount of stuff.
13:29	sritchie	hey guys, I'm running into what might be a bug with inlined functions
13:29	sritchie	https://gist.github.com/1551640
13:30	TimMc	&((fn [& {:keys [a b]}] nil) :a 1 :b) <-- amro: you were probably calling a function with keyword args like this one but missing a param
13:30	lazybot	java.lang.IllegalArgumentException: No value supplied for key: :b
13:30	sritchie	the environment seems to be interpreting ^bytes as a var, not a type hint
13:30	jodaro	hrm
13:30	sritchie	but only the second time I evaluate that form
13:31	jodaro	that "works", but the resulting byte buffers seem to be longer than i expect
13:31	jodaro	if i encode ["foo" "bar"]
13:31	yoklov	clj_newb: LLVM isn't always JIT compiled, it's just availiable as an option. I don't really know, but that at least leads me to believe that it might not be their strongest area.
13:31	jodaro	i guess i'd expect 8 bytes
13:33	TimMc	sritchie: "Can't type hint a local with a primitive initializer"
13:34	clj_newb	lypanov , yoklov: so the core is: "JIT in Java is automatic. JIT in LLVM requires manual work." ?
13:34	sritchie	TimMc: yeah, hinting the original x and y doesn't pass through to the inline definition, unfortunately
13:34	sritchie	TimMc: can you think of any way to hint those arguments?
13:35	TimMc	sritchie: Never mind, that was my bad -- I was passing in junk.
13:35	TimMc	and I get the exception you see on the first call.
13:36	TimMc	sritchie: (java.util.Arrays/equals ^bytes ~x ^bytes ~y)
13:37	TimMc	sritchie: Also, you might use reduce.
13:38	amro	TimMc: thanks
13:38	TimMc	sritchie: The reduce idea might need work...
13:38	amro	but it said true, not :true, so it was building a map with true as a key I guess?
13:38	TimMc	amro: That's my guess.
13:39	TimMc	&(hash-map true)
13:39	lazybot	java.lang.IllegalArgumentException: No value supplied for key: true
13:39	TimMc	&(hash-map :true)
13:39	lazybot	java.lang.IllegalArgumentException: No value supplied for key: :true
13:39	amro	yep, I just tried that
13:39	amro	well, in any case I was misusing the API
13:41	yoklov	clj_newb: That could be it. If you really want more information, see if LLVM has an irc channel and ask them there. The clojure channel isn't likely to have many people who would know what optimizations LLVM does during JIT compilation.
13:42	sritchie	TimMc: that doesn't seem to pick up the type hint, unfortunately
13:44	lypanov	llvm has a irc channel on oftc
13:45	lypanov	clj_newb: pretty much, though i'd rather say JIT in JVM has 30 years worth of experience fixing crap code.
13:45	lypanov	clj_newb: llvm OTOH has very different goals. it is just an insanely great machine code generator.
13:46	lypanov	clj_newb: you might also want to try #rubinius some of the guys there have actual experience, i just have 2nd hand guesses ;)
13:51	mattmitchell	if i used an atom as a way to more easily change state of a map, in a non-multi-threaded program, would this be considered misusing an atom?
13:54	jodaro	i think it depends on why you need to do it that way
13:54	TimMc	sritchie: Hmm, how can inlining be debugged?
13:54	sritchie	I'm not sure, I don't really know the expansion rules
13:56	clj_newb	this is starting to make sense now
13:56	clj_newb	I always wondered why such a brilliant langauge like clojure picked java
13:56	clj_newb	now I get it: it makes impelmenting clojure much much easier
13:56	yoklov	versus llvm?
13:56	clj_newb	no need to implement a VM, a FFI, or a JIT
13:56	clj_newb	it's all provided by java
13:57	yoklov	Or the hundreds of libraries that come with java.
13:57	TimMc	":inline-arities >1?" <- wtf
13:57	clj_newb	Thus, all the effort of implementing clojure goes into implementing the new ideas that clojure provides; rather than the bitch work of setting up the core of a basic language.
13:57	mattmitchell	jodaro: well, there is a function with a lot of nested conditions. I was going to use reduce, but using an atom made it clear since, I only update the map if all of these nested conditions are met by calling swap!
13:57	TimMc	Oh, it's a private fn.
14:03	lypanov	clj_newb: there is a project called vmkit that if it were to be improved could offer all the advantages of JVM and llvm
14:03	lypanov	but it'd be years of work
14:03	lypanov	and openjdk is okay ish now
14:03	clj_newb	Currently asking in llvm on irc.oftc.net
14:04	clj_newb	I really like Clojure's approach to concurrency (immutability + vars + atoms + agents + stm); if only I could write programs that did not require the JVM like that ... :-)
14:06	mattmitchell	is there a built-in function for turning a collection of hash-maps into a hash-map, where the keys come from the values of the maps in the collection? Example: (some-fun [{:id 1} {:id 2}] :id) => {1 {:id 1} 2 {:id 2}} etc..
14:08	TimMc	mattmitchell: Ill-defined, what happens with key collisions?
14:08	TimMc	Or can you assume there are none?
14:08	mattmitchell	TimMc: it can blow up in that case
14:08	mattmitchell	yeah, there shouldn't be any
14:08	mattmitchell	I'm using reduce right now, but it seems too complex
14:08	TimMc	for might be better
14:09	lypanov	clj_newb: you could, use clojurescript + v8 and implement it all on top of js "threading" concepts ;)
14:09	TimMc	mattmitchell: And maps are fine, no need to specify hash-maps.
14:09	mattmitchell	TimMc: ahh right
14:09	mattmitchell	TimMc: could you give me a hint on the "for" approach? :)
14:11	jodaro	hrm, well, treating it as a single string and then splitting it on \x00 works for now
14:11	TimMc	&((fn [fk & ms] (into {} (for [m ms] [(m fk) m]))) :id {:id 1 :a 2} {:id 5 :b 4}) ;; mattmitchell
14:11	lazybot	⇒ {1 {:a 2, :id 1}, 5 {:b 4, :id 5}}
14:12	mattmitchell	TimMc: awesome thanks
14:12	TimMc	mattmitchell: I think you could sneak a juxt in there, actually.
14:13	mattmitchell	oh maybe juxt and zipmap?
14:13	TimMc	&((fn [fk & ms] (into {} (map (juxt fk identity) ms))) :id {:id 1 :a 2} {:id 5 :b 4}) ;; assumes focal key is a keyword or symbol or other IFn
14:13	lazybot	⇒ {1 {:a 2, :id 1}, 5 {:b 4, :id 5}}
14:13	mattmitchell	ahh i see
14:20	clj_newb	based on discussions on oftc llvm: ... Why is JITTing important to clojure? There are other scheme implementations, like Chicken ... that appear to be doing file while compiled. How exactly does Clojure use JITting?
14:25	TimMc	clj_newb: One cool thing is that with JIT, macros can expand in different ways depending on what libraries are available, or what version of Clojure is in use.
14:26	clj_newb	TimMc: how does macros related to JITTing?
14:26	lypanov	that can be done without JIT if the system applies system wide opts.
14:26	clj_newb	oh, macros can be done at _runtime_ ?
14:26	clj_newb	rather than multiple compilation passes?
14:27	TimMc	clj_newb: Yeah, JIT means you are distributing source, unexpanded.
14:27	amalloy	i think you two are confusing each other
14:27	clj_newb	amalloy: enlighten us
14:27	TimMc	oh no, an expert!
14:27	amalloy	TimMc is just saying that the compilation happens in the same environment where code is going to execute
14:27	amalloy	so you know what will be available
14:28	clj_newb	How does this related to JITTing?
14:28	raek	The oracle implementation of the JVM (Hotspot) uses JIT compilation to speed up the virtual machine.
14:28	amalloy	it's not related to java's JITing, but it is basically clojure's JIT: compile it Just In Time, before they run it
14:28	amalloy	clojure doesn't care at all about java's JIT; it just runs on the jvm and gets a performance boost for free
14:29	TimMc	Yeah, I guess there's a jargon mismatch here.
14:29	AeroNotix	What's a good method for type checking in clojure?
14:29	TimMc	Clj -> .class -> native machine code -- both of those steps are compilations.
14:30	clj_newb	amalloy: ah, the point you're getting at is (1) Just in Time macro expansion vs (2) Just in Time compilation + code execution ?
14:30	amalloy	no
14:30	TimMc	&(instance? String "AeroNotix")
14:30	lazybot	⇒ true
14:30	AeroNotix	Thank you
14:30	amalloy	that's the point that is dividing you and TimMc
14:30	AeroNotix	@TimMC thank you
14:30	TimMc	AeroNotix: isa? can do some fancier stuff
14:30	AeroNotix	thanks, I'll get to google
14:30	amalloy	i guess maybe that's the point i was getting at also
14:31	amalloy	but it's not just "JIT macro expansion", because clojure really does compile all the code right before it runs. it has to expand the macros to do it, but...
14:34	lypanov	JIT implies continuous. clojure isn't continuous.
14:34	lypanov	there is no "hotspot" detection in clojure's compiler. its just a compiler.
14:39	clj_newb	the more I learn about clojure; the more brilliant I think it is
14:40	clj_newb	I bet there's even a good, perfectly valid reason, why clojure does not have a builtin (make-me-a-sandwhich :meats '(beef pepperoni) :vegetables '(pickles onions))
14:40	AeroNotix	clj_newb: It does?
14:41	lypanov	clj_newb: glad you get it now, i decided to go down the scala road a year back after a quick dive into clojure burnt me and deeply regret it. back again.
14:44	clj_newb	lypanov: what did you like about scala / how did it burn you?
14:44	lypanov	clj_newb: i liked the fact that i could learn it fast as its similar to other things i've used and that it had a ton of cool language features.
14:44	lypanov	clj_newb: i was burnt my its complexity.
14:44	lypanov	by*
14:45	lypanov	i also simply couldn't deal with the compile times.
14:45	lypanov	its 2012!
14:45	lypanov	;)
14:55	lypanov	anyone else read lwn.net & have a kindle?
14:56	lynaghk	lypanov; have you seen the Send-to-Kindle google chrome extension? It's pretty decent at extracting article text and formatting for Kindle
14:57	lypanov	lynaghk: i'd really like to have a .mobi with nice headers and a ToC etc
14:57	lypanov	i want to dissect whatever magic instapaper is performing is thats the format i'd like
14:59	lynaghk	Ah, makes sense. I've used Amazon's standard html to mobi converter on a few projects with luck, so hopefully it won't be too difficult.
14:59	lynaghk	Good luck
15:01	lypanov	yeah probably going to use kindlegen for it if i can get it to produce the right file
15:01	lypanov	thank you :)
15:03	AWizzArd	When I eval out, a ^:dynamic var under Clojure 1.3, is that then equivalent to @#'out, from an efficiency point of view?
15:04	AWizzArd	I noticed that (time (dotimes [i 10000000] out)) and (time (dotimes [i 10000000] @#'out)) take the same amount of time, vs. (time (dotimes [i 10000000] "hi")), which is much faster (as I expected).
15:07	holo	hello
15:09	AWizzArd	My understanding is: as out and err are dynamic vars, Clojure needs to deref them at runtime, where deref means: look up the current thread-local value. And this should be equivalent to dereferencing a var. Yes/No?
15:10	amalloy	AWizzArd: it's probably similar, though i suspect out is a little easier to inline. why not write both functions, AOT-compile them, and look at the bytecode?
15:11	AWizzArd	amalloy: my background, why I came up with this question is that I want to write a logging function which can log to out, and one which logs to err. Both fns are 5-liners and are identical, with the exception of their arg to the .write method.
15:12	AWizzArd	So instead it would be the right thing to have a factory fn instead, which gets called with those two args. But that of course would make those two logging functions statically log into whatever value out or err had when I called the factory.
15:13	amalloy	huh? why of course? i don't think i understand you
15:13	AWizzArd	(def out-logger (make-logger out)) <-- out-logger always .writes to the same Writer.
15:13	amalloy	(make-logger #'out)
15:13	AWizzArd	Exactly.
15:13	AWizzArd	This would work.
15:14	AWizzArd	But then: (.write #'out ...) doesn’t. Of course, because it expects a Writer, not a Var.
15:14	AWizzArd	So I would have to deref the arg to make-logger.
15:14	amalloy	right
15:14	AWizzArd	And when I realized this I thought: will this be less efficient than writing explicitly (.write out ...)?
15:15	AWizzArd	The dotimes micro benchmark from above indicates that it makes no difference at all.
15:15	AWizzArd	But looking at the bytecode seems like a reasonable idea.
15:16	amalloy	AWizzArd: i'm doing that already, i'll let you know
15:16	AWizzArd	Oh good, thx.
15:17	simonadameit	Hi, can I add functions (maybe even private ones) to a deftype without implementing an interface?
15:18	AWizzArd	simonadameit: but you still want polymorphism?
15:18	AWizzArd	Because otherwise you could just write an ordinary defn or defn- for the private version, which expects one or more instances of a deftype.
15:18	raek	simonadameit: if they do not participate in the protocol, you can just have them outside the defrecord form
15:18	amalloy	AWizzArd: @#'out has more obvious work in it: https://gist.github.com/1551956
15:18	raek	as ordinary functions
15:19	simonadameit	raek: you mean without specifying them inside the deftype form?
15:19	raek	yes
15:19	AWizzArd	amalloy: hmm I see
15:20	raek	(defn- foo [...] ...) (defrecord Bar [...] SomeProto (some-method [...] ... (foo ...) ...))
15:20	amalloy	mainly because you have to actually call clojure.core/deref, i think
15:20	amalloy	as compared to just calling .get on the var
15:21	AWizzArd	amalloy: then I either have to 1) accept this extra work from deref, or 2) duplicte code and write out both fns explicitly or 3) write a macro
15:22	simonadameit	raek but they wont be implemented as methods directly defined in the class backing the deftype?
15:22	raek	simonadameit: yes.
15:23	raek	they will be implemented as a method in a function class instead
15:24	raek	the reason you want to have protocol methods implemented as java methods is fast polymorphism
15:24	simonadameit	ah, ok.. I dont need polymorphism for these functions
15:24	raek	but for a private helper function that is only used in one implementation of the protocol you don't use any polymorphism
15:25	raek	exactly
15:28	simonadameit	thanks raek, .. I guess I will have to get used to this separation of function and data :)
15:29	AWizzArd	amalloy: interesting, it seems there is then no other way to parameterize on dynamic vars.
15:30	amalloy	hm? you could do .get on the Var with interop instead of using the more generic deref, since you don't need genericity
15:32	AWizzArd	amalloy: calling .get will probably also result in more code than what you got for (defn foo [] (println out)).
15:33	amalloy	not really. it should just add a single checkcast to that version
15:34	amalloy	and even that much shouldn't be necessary; if the compiler were able to detect that you only use the value once and always treat it as a Var it could do the cast once and forget it
15:36	simonadameit	what is the name of the protocol that conj is part of?
15:37	amalloy	it's an interface
15:37	amalloy	clojure.lang.IPersistentCollection/cons, i think
15:39	raek	simonadameit: this can be useful: https://github.com/Chouser/clojure-classes/blob/master/graph-w-legend.png
15:40	augustl	is there a way to disable all of the built-in pages of noir? Such as the default 404 page for example.
15:41	simonadameit	raek thanks, thats great
15:43	simonadameit	is there a performance difference between using extend-type or defining the methods directly in a deftype`
15:43	simonadameit	?
15:44	amalloy	yes, but not one that's likely to matter if you're implementing something slower than hello world
15:49	bweaver	Hello, does Clojure memoize regex pattern objects when they're written in the #"..." literal format? I'm writing a predicate function that uses re-matches and wonder if there's a performance advantage to declaring the regexp pattern separately vs using it inline.
15:53	amalloy	those are reader macros, so the objects should be embedded in the code
15:53	amalloy	ie, no memoization is necessary
15:54	raek	bweaver: if you're wondering whether #"..." will only instantiate a Pattern once, then yes (IIRC)
15:54	bweaver	Ok, thanks.
15:59	Xenocorp_	in emacs repl. If I shadow a built-in, how do I reset the repl?
16:03	bweaver	Xenocorp_: You can `(use 'clojure.core)` to re-import all of the core bindings into your namespace. Does that help?
16:04	Xenocorp_	bweaver: That'll do :)
16:04	Xenocorp_	Thanks
16:15	augustl	is there a reference to all the syntax in clojure? Currently trying to find out what the ampersand in (defn foo [& something] ....) means
16:16	bweaver	augustl: I find that the cheatsheet is helpful `http://clojure.org/cheatsheet`, most other reader stuff is documented in `http://clojure.org/reader`.
16:17	bweaver	augustl: The amphersand captures the rest of the arguments. So in your example, it means `foo` will accept any number of arguments and they'll be bound into a list called `something`.
16:17	augustl	ah that cheat sheet is useful
16:17	bweaver	augustl: So, for example, calling `(foo 1 2 3)` will bind `something` to `(list 1 2 3)`.
16:17	bweaver	augustl: Or maybe it's a vector.
16:17	augustl	I see, thanks
16:18	amalloy	neither, actually. but you get a sequential view of it, which is all that matters
16:19	bweaver	Thanks amalloy :)
16:19	amalloy	&((fn [& args] (class args)) 1 2 3)
16:19	lazybot	⇒ clojure.lang.ArraySeq
16:19	augustl	found the docs in http://clojure.org/special_forms
16:19	augustl	for the record
16:19	Scorchin	If I'm using clojure 1.3, how do I add clojure-contrib to my project?
16:22	augustl	Scorchin: I'm using leiningen, I added [org.clojure/clojure-contrib "1.2.0"] to dependencies in project.clj
16:22	Scorchin	augustl: is 1.2.0 the latest stable version? The website wasn't very clear on that
16:22	technomancy	clojurebot: what happened to clojure contrib?
16:22	clojurebot	It's greek to me.
16:22	technomancy	clojurebot: what happened to contrib?
16:22	clojurebot	Well... it's a long story: http://dev.clojure.org/display/design/Where+Did+Clojure.Contrib+Go
16:22	amalloy	if you want old-contrib in a 1.3 project, step one is ritual suicide
16:23	Scorchin	technomancy: <3
16:23	augustl	Scorchin: don't remember how I found that version number, I remember struggling with that as well
16:30	augustl	given (def foo [:my :vector]) (def bar [:other :vector foo]), is there a way to make the value of bar [:other :vector :my: :vector] instead of [:other :vector [:my: :vector]]?
16:30	amro	in what case would (print (str (type x))) output nothing?
16:30	Scorchin	interesting, if I load up a plain repl and type: (clojure.string/split-lines "test \n string") it throws the following error: ClassNotFoundException clojure.string java.net.URLClassLoader$1.run (URLClassLoader.java:202)
16:30	Scorchin	Anyone what's going on there?
16:31	technomancy	Scorchin: you haven't loaded the clojure.string namespace
16:32	bweaver	augustl: `(vec (flatten bar))`?
16:32	Scorchin	technomancy: thank you
16:33	augustl	bweaver: cool, thanks
16:33	nick_s	Is let free?
16:34	bweaver	augustl: You could also use `concat` depending on whether you needed the intermediate nested vector for anything.
16:34	nick_s	After it's compiled that is. Does a let binding have a performance cost associated with it?
16:34	amalloy	if what you want is [:other :vector :my :vector], then your "given" (def foo [:my :vector]) (def bar [:other :vector foo]) means you started wrong
16:36	mcrittenden-afk	noir's built in server isn't meant to be used in production, right? and if not, then what are people using?
16:37	mcrittenden-afk	oh just realized it uses jetty which I assume would be fine in production. never mind.
16:37	Xenocorp_	apparently at my work we're using two toasters strapped together with an ethernet cord
16:40	augustl	pastie can't highlight lisps it seems, any suggestions? :)
16:40	amalloy	~paste
16:40	clojurebot	paste is gist
16:40	amalloy	ugh, really?
16:40	amalloy	clojurebot: forget paste \|is\| gist
16:40	clojurebot	I forgot that paste is gist
16:40	amalloy	clojurebot: paste is https://gist.github.com
16:40	clojurebot	c'est bon!
16:41	technomancy	paste is delicious
16:41	augustl	thanks
16:41	zilti	amalloy: pastie.org can highlight Clojure: http://pastie.org/l
16:41	augustl	since I don't know much about clojure, it seems to me that these calls would be identical https://gist.github.com/1552241
16:41	augustl	is there an easy explanation for a noob? :)
16:42	augustl	just seems to me that (vec (flatten head-extra)) evaulates to a vector, i.e. exactly the same as head-extra
16:42	amalloy	zilti: i have no opinion about pastie, but he asked for a good pastebin, and that's gist
16:42	technomancy	flatten?
16:42	clojurebot	flatten is rarely the right answer. Suppose you need to use a list as your "base type", for example. Usually you only want to flatten a single level, and in that case you're better off with concat. Or, better still, use mapcat to produce a sequence that's shaped right to begin with.
16:42	amalloy	~botsnack
16:42	clojurebot	Thanks! Can I have chocolate next time
16:42	bweaver	augustl: You might want to try appending head-extra instead of inserting it into the vector literal.
16:42	zilti	amalloy: I prefer gist, too
16:43	amalloy	bweaver: nah, that shouldn't matter
16:43	augustl	bweaver: it's nice to keep the literal structure when doing HTML..
16:44	augustl	anyhow, is "flatten" a special form of some sorts that makes stuff happen under the hood?
16:44	amalloy	no, flatten is a great evil sent by the devil
16:44	bweaver	augustl: no, it's just a function
16:44	amalloy	included only to confuse people into using it when they shouldn't
16:44	augustl	still don't quite grok the difference between the two calls, since vec evaulates to a vector (I guess)
16:45	amalloy	augustl: the difference is, what if head-extra is [:foo [:bar [:baz]]]
16:45	amalloy	flatten turns it into [:foo :bar :baz]
16:45	augustl	the only thing I can think of is that "flatten" sets some state under the hood that causes clojure to evaulate the vector differently
16:45	augustl	ah we wouldn't want that..
16:46	bweaver	augustl: for what it's worth, you might try using quasiquoted lists instead of vectors for representing markup
16:46	bweaver	augustl: `(:head (:title "...") ~@head-extra)
16:46	amalloy	bweaver: i have to wonder what position you're giving advice from. hiccup uses vectors
16:46	augustl	wonder if hiccup supports that
16:46	augustl	ah, right
16:46	bweaver	amalloy: oh, didn't know that
16:47	bweaver	amalloy: I'm new to Clojure too and just find quasiquotes convenient. If there's a framework already, then that's definitely more convenient :)(
16:47	bweaver	amalloy: This is what I was thinking of: http://okmij.org/ftp/Scheme/SXML.html
16:47	augustl	the value of head-extra in my case is ["Test test"], so I still don't understand how flatten helps me in this case :)
16:47	augustl	I do understand it will turn nested lists into flat lists
16:47	bweaver	augustl: Sorry augustl, ignore me :)
16:47	augustl	not how it "concatinates" vectors into other vectors, inline, sort of
16:47	bweaver	augustl: I was assuming something different than what you're trying to do.
16:48	amalloy	it doesn't help you, flatten never helps, i wish i could remove it from clojure.core
16:48	augustl	it does actually help me in this situation, though
16:48	augustl	perhaps my head-extra vector doesn't have the value I think it does..
16:48	amalloy	no, it obviously doesn't, because (vec (flatten ["foo"])) ie still ["foo"]
16:49	amalloy	if your goal is to end up with the contents of head-extra dumped into the head, you want ##(doc into)
16:49	lazybot	⇒ "([to from]); Returns a new coll consisting of to-coll with all of the items of from-coll conjoined."
16:49	amalloy	(into [:head [:title ...] ...] head-extra)
16:49	amalloy	or if you prefer, `[:head [:title ...] ... ~@head-extra]
16:50	augustl	updated https://gist.github.com/1552241, build-head-3 works and I understand it, so yay :)
16:50	augustl	amalloy: hmm that's interesting, I wonder why build-head and build-head-2 behaves differently then
16:50	augustl	that's good to hear, at least, that means I did actually understand what flatten did ;)
16:50	skelternet	I've been building tables with hiccup.
16:51	augustl	amalloy: ah I'll look up the ~@foo syntax
16:51	skelternet	I noticed some of the tags seem to only respect one parameter the way I had been using them.
16:52	technomancy	warms my heart seeing all these folks learning Clojure for 2012 =)
16:52	cgray	is there any way to get a clear picture of how much memory is actually being used by a clojure process? top just shows how much the jvm has allocated, which i guess is usually more than is used
16:53	skelternet	for instance, I had a [:tr (for … (println something) [:td column] … and the td's weren't getting returned
16:53	augustl	odd, "Attempting to call unbound fn: #'clojure.core/unquote-splicing ", guess I need to import something
16:53	skelternet	Don't know if that helps, agustl,
16:53	skelternet	I'm still trying to wrap my head around it.
16:53	augustl	skelternet: hmm, you probably need to map instead of for looping?
16:53	amalloy	augustl: you didn't include `
16:53	augustl	not sure what a for loop that prints is doing inside a vector that's supposed to represent HTML :)
16:54	skelternet	was just there while debugging…but it seemed to make things worse while it was there :\|
16:54	skelternet	when I removed it, life was better
16:54	augustl	amalloy: include what? :)
16:55	cgray	augustl: the backtick symbol
16:55	augustl	oh
16:55	amalloy	&(let [x 1] `(:foo ~x))
16:55	lazybot	⇒ (:foo 1)
17:04	clj_newb	I need to gain 6000 experience points to advance from clj_newb to clj_novice. What are good clojure codebases to read?
17:04	cgray	clj_newb: core.clj is a pretty good place to do some learning
17:05	cgray	clj_newb: sorry, I mean clojure.core
17:05	amalloy	downvote. core is interesting once you already know a lot
17:05	amalloy	but it contains a ton of stuff that is a Bad Idea in other code because it's bootstrapping
17:05	cgray	good point
17:05	cgray	maybe the second half of core or so
17:05	pandeiro	amalloy: anything you'd recommend?
17:06	clj_newb	"bootstrapping" <-- as in the code is not idiomatic, because clojure idioms requires things in clojure.core ?
17:06	amalloy	right
17:06	clj_newb	actually, that sounds awesome; I love understanding how things work
17:07	amalloy	shrug what you should read depends on what you want to learn
17:07	clj_newb	the great thing about software, as opposed to hardware is that I don't have to put it back together
17:08	clj_newb	amalloy: this is an honest question. Why are you so well respexcted in this channel? Did you write some library in clojure.core or clojure.contrib?
17:09	amalloy	haha no, it's because i spend a lot of time in here. i have more fun helping out than writing a magnum opus
17:09	amalloy	but a lot of www.4clojure.com is mine, if you're looking for an excuse to idolize me
17:10	clj_newb	I merely found it interesting how that whenever you disagree with someone, they just assume you're right. :-)
17:10	clj_newb	what does 4clojure have to do with cheap realestate?
17:10	amalloy	foreclosure
17:10	amalloy	it's a pun, you see. not my pun, thank god
17:11	cgray	clj_newb: the damn thing is, he is right so much of the time... plus it's just a pretty respectful community in general
17:13	augustl	clj_newb: currently making a simple web page with Noir. Learning a lot from that.
17:13	augustl	I got about 200 experience points after a couple of hours!
17:14	clj_newb	augustl: lol
17:15	clj_newb	amalloy: I have an exercise suggestion for 4clojure.com: "Input: a 3SAT formula. Output: in polynomial time, iether true or false, stating whether the formula is staifisable."
17:15	amalloy	i don't know what 3SAT is. but solve 50 4clojure problems, then you can submit that as a problem yourself
17:18	amalloy	haha, were you trolling me? you: "output in polynomial time..." wikipedia: "3-SAT is NP-complete..."
17:22	clj_newb	amalloy: look up millenium prize -- a solution is worth 1 million dollars. Additionally, it's probably also worth a turing award. :-)
17:22	amalloy	sure, i know. as a kid i figured i would win that prize by solving minesweeper
17:23	clj_newb	damn, it is NP complete
17:23	clj_newb	amalloy: how old are you? the Clay prize isn't that old, and you mention "as a child ..."
17:24	amalloy	yeah, "kid"
17:24	amalloy	i must have been like 17 at the time. 26 now
17:46	solussd	is there something clojure more generic than (Long/parseLong "1367") ?
17:47	solussd	i.e. something that'll work on any number
17:47	amalloy	&(doc read-string)
17:47	lazybot	⇒ "([s]); Reads one object from the string s"
17:47	solussd	,(read-string "387429837492387492734923794729347923749")
17:47	clojurebot	387429837492387492734923794729347923749N
17:49	wingie	is clojure fine to script with?
17:49	AWizzArd	solussd: I don’t know about the efficiency, but there is also a .parse method in http://docs.oracle.com/javase/7/docs/api/java/text/DecimalFormat.html available.
17:49	wingie	compared to groovy
17:50	solussd	,(.parse "23984294832.23423")
17:50	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: No matching field found: parse for class java.lang.String>
17:51	solussd	oh, duh.
17:51	AWizzArd	Yes, I think the String class doesn't provide such a .parse method.
17:53	AWizzArd	This DecimalFormat class also provides parsing for some more exotic formats. Though as long read-string works fine I would surely prefer that one.
17:55	AWizzArd	http://docs.oracle.com/javase/tutorial/i18n/format/decimalFormat.html
17:56	TimMc	solussd: Just be sure to (binding [read-eval false] ...) around that for security.
17:56	TimMc	wingie: If you don't mind the several-second startup time of the JVM, sure, it's fine to script with.
17:56	solussd	yeah, I think that's overkill for me. :)
17:57	TimMc	solussd: Well, as long as you aren't reading user-generated strings, OK.
17:57	solussd	oh, you're referring to 'read-string'
17:57	TimMc	Yeah, sorry.
17:58	TimMc	wingie: Compared to any other JVM language I know of, yes, Clojure is the best for scripting -- LISPs are great for extracting patterns.
17:59	solussd	TimMc, what could be fed to read-string that would result in evaluation?
17:59	TimMc	&(read-string "#=(+ 1 2)") ; solussd
17:59	lazybot	java.lang.RuntimeException: EvalReader not allowed when read-eval is false.
17:59	TimMc	Semi-undocumented syntax.
18:00	solussd	yikes
18:00	TimMc	I've opened a ticket to document that in read and read-string -- it's an "unsupported feature", but the lack of documentation is outright dangerous.
18:00	solussd	what does #= mean exactly?
18:01	TimMc	solussd: It means to use the results of evaluating the next form.
18:02	TimMc	solussd: Put (read-string "[(+ 1 2) #=(+ 1 2)]") into a REPL.
18:03	TimMc	clojurebot is stupid, I can demonstrate here:
18:04	TimMc	,(binding [read-eval true] (read-string "[1 2 #=(- 7 4) 4]"))
18:04	clojurebot	[1 2 3 4]
18:04	TimMc	The main use is serializing data structures that don't have literal support.
18:05	solussd	TimMc: whoa. So I could force evaluation of macro arguments when I pass them
18:05	TimMc	Not following that.
18:06	TimMc	Seriously, don't use #= in your code -- it's probably going away.
18:06	chipdude	so #=() is a lift macro
18:07	solussd	(defmacro printform [form] `'~form)
18:07	TimMc	It's reader syntax.
18:07	wingie	TimMc: is there any way to eliminate the startup time for java? (im new to java)
18:07	chipdude	[1 #=(prn 2) (x)]
18:07	chipdude	2
18:07	chipdude	java.lang.Exception: Unable to resolve symbol: x in this context (NO_SOURCE_FILE:2)
18:08	solussd	then I could (printform #=(+ 2 1)) to force it to pass 3
18:09	chipdude	TimMc: what will replace it
18:14	TimMc	chipdude: Nothing official, I'm just guessing.
18:15	TimMc	I think it was mainly used for records, which now have their own (also undocumented!) literal syntax.
18:18	TimMc	technomancy: Did you take a look at the no-AOT uberjar example I wrote?
18:24	amalloy	TimMc: i don't think #= is actually going away anytime soon, but it's definitely something to avoid anyway
18:24	TimMc	amalloy: Do you know what else it is used for?
18:24	amalloy	&(print-dup (sorted-set))
18:24	lazybot	clojure.lang.ArityException: Wrong number of args (1) passed to: core$fn--4023$fn
18:25	amalloy	&(binding [print-dup true] (pr-str (sorted-set)))
18:25	lazybot	java.lang.SecurityException: You tripped the alarm! pop-thread-bindings is bad!
18:25	TimMc	Ah, right.
18:25	TimMc	clojurebot won't mind
18:25	amalloy	damn it Raynes, can you just let the thread-binding stuff back into the list? he is crippled without binding
18:25	amalloy	,(binding [print-dup true] (pr-str (sorted-set)))
18:26	clojurebot	"#=(clojure.lang.PersistentTreeSet/create [])"
18:27	TimMc	amalloy: pop-thread-bindings is only found in the macro expansion -- does clojail really need to inspect the expansion results?
18:27	TimMc	(Or rather, why.)
18:28	amalloy	&(macroexpand '(clojure.lang.Compiler/eval foo))
18:28	lazybot	java.lang.SecurityException: You tripped the alarm! class clojure.lang.Compiler is bad!
18:29	augustl	someone told me earlier what I had to do to enable ~@ (unquote-splicing), but I didn't grok what it was.. Anyone knows?
18:29	augustl	getting "Attempting to call unbound fn: #'clojure.core/unquote-splicing"
18:29	amalloy	ugh, whatever. the point is there are a lot of "special cases" where stuff doesn't look like a problem until it's expanded
18:29	skelternet	I might have it in a buffer, do you need it or need to grok it?
18:30	TimMc	amalloy: I see, lots of sugary stuff.
18:31	TimMc	doto, etc.
18:31	amalloy	right. but you make an interesting point, i think
18:31	augustl	skelternet: need to grok it :)
18:31	amalloy	i (or Raynes?) just macroexpanded because it seemed like you could hide dangerous things inside a macro
18:32	augustl	need to import `, not sure how to do that
18:32	chipdude	TimMc: the record syntax is as found here? http://dev.clojure.org/display/design/defrecord+improvements
18:32	amalloy	there's nothing to import
18:33	augustl	oh, I'm probably using it wrong then
18:33	amalloy	TimMc: actually i think memfn was the macro that makes it necessary to expand
18:33	TimMc	Ah, right.
18:34	TimMc	So you'd have to look at all the things that mess with names and calling. Ugh.
18:34	TimMc	&`[1 2 3 ~@(list 4 5 6) 7 8] ; augustl
18:34	lazybot	⇒ [1 2 3 4 5 6 7 8]
18:35	technomancy	TimMc: yeah, makes it sense
18:36	technomancy	maybe package it up as a plugin?
18:36	TimMc	I'm trying to think how exactly.
18:37	TimMc	There's also the question of how to indicate that this is the desired behavior.
18:37	technomancy	if you had it read the main ns out of jar metadata, you could probably just make it a plain old dependency
18:37	technomancy	wouldn't need to be a plugin
18:38	TimMc	I was thinking a resource like uberjit.properties
18:39	TimMc	But no, that's silly -- there might be multiple.
18:40	jmdev	Hi guys
18:40	technomancy	jar metadata lives in project.clj right next to :main; it makes sense to keep them together
18:41	augustl	I
18:41	augustl	err
18:41	augustl	I'd appreciate if you could tell me how horrible my build-main-menu from https://gist.github.com/1552654 is, and how it could be better :)
18:42	amalloy	(defn ... (def)) is evil
18:42	augustl	I should inline it?
18:42	raek	augustl: def is only for global constants
18:42	amalloy	no, you should never use def inside a defn
18:42	amalloy	you want let
18:43	augustl	ah
18:43	augustl	a "minor" oversight..
18:43	skelternet	would the inner def survive outside of the scope?
18:43	skelternet	tag-attrs in this case?
18:43	raek	skelternet: it will mutate a global variable
18:43	augustl	I'm curious if my use of concat of vectors makes sense. Not used to functional programming and static collections
18:44	augustl	and if having a build-main-menu-iter makes sense. Inspired by SICP which I just started reading ;)
18:44	yoklov	haha i thought your code looked like scheme code
18:44	yoklov	but wasn't going to say anything because mine does too lol
18:44	augustl	recur is the only "trick" I learned so far ;)
18:45	TimMc	skelternet: The inner def would not become defined until that function had been called.
18:46	amalloy	the manual recursion looks a lot like a map or a mapcat or something
18:46	skelternet	I thought mutations to it were stacked and thread-specific. I must be thinking of bind
18:46	amalloy	but it's hard to tell because you wrote it as manual recursion and now it takes all this effort to read :P
18:46	augustl	guess I could use conj instead of concat-ing vectors
18:46	augustl	amalloy: hehe, the idea is that I need to pass active-menu to the calls to build-main-menu-item
18:46	augustl	seems that map only passes the item in the collection and doesn't support arbitrary params
18:47	raek	skelternet: yes, when using 'binding' and 'set!'
18:47	arohner	using clj-http, is there any way to set a lower timeout for a request? i.e. "throw if this request takes more than N seconds to finish"?
18:47	augustl	hmm seems conj isn't what I need
18:48	skelternet	def will just mutate it…whenever def gets eval'd? that would be much more difficult to reason about
18:48	raek	but 'def' is for those cases when you unconditionally want to change a global in all threads (unthreadsafely) -- nameley when fixing existing code
18:48	amalloy	(defn build-main-menu [active-menu] (mapcat #(build-main-menu-item % active-menu) main-menu-links))?
18:48	raek	skelternet: yes
18:48	raek	it should normally only be used on the top level
18:48	skelternet	same for defn?
18:48	raek	yes
18:48	augustl	amalloy: ah, mapcat looks nice
18:49	raek	think of 'def' as define global / repair broken global
18:49	augustl	and #() is shorthand for a lambda/anon function right?
18:49	yoklov	yes
18:50	raek	skelternet: (defn foo ...) is just a shorthand for (def foo (fn ...))
18:50	yoklov	you can also use fn which is the same as lambda.
18:50	raek	it's a macro
18:50	augustl	hah, awesome
18:51	skelternet	(dreaming of swapping out implementations of a protocol mid-execution)
18:51	augustl	now it's just https://gist.github.com/1552654
18:51	augustl	time to open The Joy of Clojure and grok what the % does :)
18:51	yoklov	it's the parameter for the #() function shorthand.
18:52	TimMc	%`#(+ %1 %3)
18:52	TimMc	&`#(+ %1 %3)
18:52	lazybot	⇒ (fn* [p1__14814__14817__auto__ p2__14816__14818__auto__ p3__14815__14819__auto__] (clojure.core/+ p1__14814__14817__auto__ p3__14815__14819__auto__))
18:52	augustl	updated it to use just map (still https://gist.github.com/1552654)
18:52	skelternet	it's almost built-in obfuscation
18:53	amalloy	yeah, the mapcat was (i think) replicating what you were doing but didn't make sense to me
18:53	raek	,(* (+ (+) (+) (+)) (+ (+) (+)) (+ (+) (+)))
18:53	clojurebot	0
18:54	raek	right
18:54	raek	,(* (+ () () ()) (+ () ()) (+ () (*)))
18:54	clojurebot	12
18:54	raek	don't forget to obfuscate your number constants!
18:54	chipdude	raek: it's at times like these I wish the mathematicians would go back to paper and leave us to our ones and zeroes
18:55	augustl	what's the % called?
18:55	augustl	hard to google..
18:55	amalloy	percent
18:55	TimMc	haha
18:55	augustl	I mean the use of % in clojure, silly
18:55	augustl	or in that particular situation, even
18:55	skelternet	oh…anon function?
18:56	augustl	isn't #() the anon function part?
18:56	yoklov	argument?
18:56	TimMc	augustl: The whole thing is referred to as a "function literal". I think that's as close as you're going to get.
18:56	yoklov	http://clojure.org/reader under "anonymous function literal"
18:56	TimMc	augustl: Right, and % is just captured by the macro.
18:56	augustl	so the % in #(build-main-menu-item % active-menu) is part of the #() syntax, which is the function literal syntax?
18:56	augustl	ah
18:57	augustl	thanks, folks
18:57	amalloy	weird to use the word "literal" in that context
18:57	TimMc	(It might not be a macro technically, but it basically acts as one.)
18:57	augustl	so % is about macros
18:57	TimMc	Nope.
18:57	yoklov	it's a reader macro, not a normal macro
18:57	amalloy	nothing about macros except in a very uninteresting sense
18:58	raek	,(read-string "#(foo % bar)")
18:58	clojurebot	(fn* [p1__81#] (foo p1__81# bar))
18:58	amalloy	raek: easier to just quote it
18:59	raek	amalloy: true.
18:59	amalloy	,'#(foo % bar)
18:59	clojurebot	(fn* [p1__106#] (foo p1__106# bar))
18:59	TimMc	amalloy: Can you think of any normal macros in Clojure that capture symbols?
18:59	TimMc	try/catch is a special form...
18:59	raek	TimMc: I think 'proxy' does it with the 'this' parameter
18:59	augustl	hmmmmmm
18:59	augustl	ah right of course
18:59	amalloy	yeah, good call raek
18:59	raek	I don't think it's considered good style, though
18:59	augustl	it just creates an anonymous function that calls the original function and passes active-menu to it
19:00	TimMc	&(let [% 5] 5)
19:00	lazybot	⇒ 5
19:00	augustl	so it's the same as (fn [index] (build-main-menu-item index active-menu))
19:00	augustl	right?
19:00	TimMc	bah
19:00	TimMc	&(let [% 5] %)
19:00	lazybot	⇒ 5
19:00	amalloy	yes
19:00	yoklov	augustl: right
19:01	augustl	and % is the way you reference args in #()
19:01	TimMc	augustl: %1, %2, %3... -- yes
19:01	TimMc	% is %1
19:01	augustl	yay :)
19:01	augustl	thanks again folks
19:01	yoklov	oh huh, you can use `this' inside proxy?
19:01	raek	the highest number used determines how many arguments the function takes
19:02	augustl	raek: that's useful, thanks
19:02	TimMc	And there's %& for rest args.
19:03	TimMc	A function with %1, %5, and %& in it will effectively have the formal params [p1 p2 p3 p4 p5 & pmore].
19:04	augustl	and this is not related to the #() macro? I'm guessing you can't do (fn [] (stuff %1 %5)) though
19:04	TimMc	It's only #().
19:04	augustl	I see
19:04	TimMc	augustl: Try using syntax-quote (`) on function literals; see how they expand.
19:05	augustl	will do :)
19:05	TimMc	They'll be ugly because of double gensym'ing.
19:05	augustl	haven't learned a new language for quite some time now. It's pretty mind blowingly awesome.
19:06	augustl	it being clojure probably helps too
19:08	raek	TimMc: augustl: ordinary quote (') works fine for this purpose as well
19:09	raek	as amalloy showed before
19:09	TimMc	raek: Ooh, right -- and only a single level of gensym.
19:10	amalloy	&`#(%)
19:10	lazybot	⇒ (fn* [p1__14849__14850__auto__] (p1__14849__14850__auto__))
19:10	augustl	aww, arrow keys doesn't work in the repl
19:10	amalloy	heh, i never realized that would have multiple gensyms. funny, TimMc
19:11	TimMc	augustl: Are you using leiningen? Install rlwrap, lein will pick it up.
19:15	solussd	in 1.3, where do I get zip-filter? I see clojure.data.zip, but it is "the future home of zip-filter"… :/
19:20	TimMc	solussd: I think it's correct.
19:21	solussd	TimMc, k. so I can't add it as a dependency in my leiningen project.clj?
19:22	TimMc	No, I mean I think it's the new location.
19:24	augustl	TimMc: I'm using leiningen yes, thanks for the tip
19:25	augustl	TimMc: that's better :)
19:25	TimMc	I can't be arsed to file a ticket to get them to fix the README.
19:28	technomancy	quick poll: what's the path to tools.jar vs (System/getProperty "java.home") for the JDK you use?
19:29	quizme	how do you write to a file from a ByteBuffer?
19:30	TimMc	technomancy: Can't find it, OpenJDK Runtime Environment (IcedTea6 1.9.10) (6b20-1.9.10-0ubuntu1~10.10.2)
19:30	TimMc	OpenJDK Client VM (build 19.0-b09, mixed mode, sharing)
19:30	technomancy	TimMc: whoa; a client JVM? are you running a 64-bit OS?
19:30	yoklov	someone mentioned that #^type was deprecated in favor of ^type. is there any difference between those, or is it being deprecated because ^type looks nicer?
19:31	TimMc	technomancy: Linux kibble 2.6.35-30-generic #61-Ubuntu SMP Tue Oct 11 15:29:15 UTC 2011 i686 GNU/Linux
19:31	quizme	I tried this: (let [fout (-> dest java.io.FileOutputStream. .getChannel)] (do (.write fout buf) (.close fout)) but it's not writing. (actually it's a HeapByteBuffer
19:31	TimMc	doesn't look like it!
19:31	technomancy	TimMc: bummer; I was hoping you had found a way to run a client JVM on a 64-bit system without compiling your own. =\
19:31	technomancy	didn't realize people still used 32-bit Oses
19:32	TimMc	technomancy: That laptop is from 2005.
19:32	technomancy	well there ya go
19:34	TimMc	technomancy: I don't like specifying the uberjit loader namespace as :main -- it confuses the reader, and more importantly, the REPL.
19:34	technomancy	hm; in that case you'd need a plugin
19:35	TimMc	And as for my Ubuntu Natty machine, OpenJDK 1.6.0_22 (x64, Server) does not have an obvious tools.jar either.
19:36	technomancy	find /usr/lib/jvm -name tools.jar gives nada?
19:36	TimMc	No, that's wrong -- it's down a level!
19:37	cgray	technomancy: /usr/lib/jvm/java-6-openjdk-i386/lib/tools.jar and "/usr/lib/jvm/java-6-openjdk-i386/jre"
19:37	technomancy	cool; thanks
19:37	technomancy	cgray: what OS?
19:38	cgray	technomancy: debian gnu/linux
19:38	technomancy	cool.
19:38	technomancy	how bout any macosecksists?
19:38	TimMc	technomancy: ../lib/tools.jar on my Server VM, nothing in my Client VM (except /usr/lib/jvm/java-1.5.0-gcj-4.4/lib/tools.jar)
19:38	technomancy	yeah... I don't think gcj really counts
19:39	TimMc	heh
19:49	technomancy	switching swank-clojure's default branch back to master; woo
20:01	TimMc	amalloy: Your clojopts project -- any plans to make a 1.3 release?
20:03	amalloy	TimMc: it's been like a year since i touched it; you're probably better off using tools.cli, though i'd love to hear why you like clojopts better
20:03	TimMc	amalloy: Well, it's the only thing I saw when I searched for "clojure getopt". :-P
20:04	amalloy	well, to be fair that's what i do that's better than cli. he rolls his own option parser which imo kinda sucks
20:04	amalloy	i used the java port of gnu getopt
20:06	TimMc	amalloy: I was looking at making clojopts 1.3 compatible. The reliance on contrib is contrib.seqs/separate (which is easy to replicate) and macro-do from your macro-utils.
20:07	TimMc	I can't tell what macro-do macro-does.
20:07	amalloy	TimMc: depend on useful instead of amalloy-utils
20:07	amalloy	templating: (macro-do [name val] `(def ~name ~val) foo 1, bar 2) => (do (def foo 1) (def bar 2))
20:08	amalloy	TimMc: if you wind up preferring clojopts but find it's missing a feature or two then a fork would be lovely. ISTR it was hard (even for me) to figure out the syntax for using clojopts, so hopefully i documented it
20:08	TimMc	You did.
20:41	TimMc	amalloy: Using useful would pin it to 1.3 -- what are your thoughts on maintaining backwards compat?
20:41	amalloy	TimMc: useful doesn't depend on anything in 1.3
20:41	TimMc	OK, sweet.
20:41	TimMc	Right, that's a soft dependency in project.clj.
21:00	TimMc	amalloy: Sweet, that was simple enough: https://github.com/timmc/clojopts/commit/5d243ffc03600e04765d49df46b36145aa8b2dee
21:03	amalloy	awesome, tests
21:08	TimMc	amalloy: Should I make the juxt change and do a pull request, or what?
21:09	amalloy	yeah, send off a pull request and i'll be happy to release to clojars
21:14	TimMc	amalloy: done
21:18	itamar	what do most people use for networking with clojure? aleph?
21:18	amalloy	TimMc: 0.3.2 on clojars
21:19	TimMc	yay
21:21	amalloy	also, "a juxty thing because heck yes". i'm concerned you may be conning me into marrying you
21:21	TimMc	haha
21:35	technomancy	itamar: "networking" is a bit too vague to be useful
21:37	rien	Raynes: it's been a few weeks, no reply whatsoever (re nixeagle's live emacs buffer)
21:40	devn	to anyone out there reading: start a clojure meetup group in your area if one does not exist. there is a coupon for clojure meetup group organizers provided by meetup.com. I started this group roughly 1 year ago and the people I've found have been incredible
21:41	skelternet	I wonder if there is one in Austin. I know there was a fp group at one point
21:41	devn	we have haskellites, scalaphiles, clojurians, schemers, lispers, and more -- a great group of people to meet and talk to.
21:41	amalloy	a coupon? does meetup cost money?
21:42	itamar	technomancy: custom TCP server, say
21:42	devn	amalloy: it does -- i dont even remember the specifics of what is and isnt included. all i remember is they offered a discount to clojure organizers. i will give them money even if that only means a free stick of gum or something
21:43	devn	just for the support for the clojure community
21:43	devn	speaking of which -- i keep looking at clojure open source projects. how do i pay for them? :)
21:44	devn	"needs moar donation buttonz"
21:45	TimMc	bitcoin ^_^
21:53	TimMc	The tricky bit is dividing the loot.
21:53	devn	I'll give it to the EFF as a donation from the clojure community or something. i dont care who gets it, just want to share my appreciation with dollar bills yall.
22:38	TimMc	amalloy: clojopts doesn't handle --nil=foo very well. :-)
22:38	amalloy	interesting
22:39	amalloy	i mean, it doesn't really matter of course, but i wonder why
22:40	TimMc	amalloy: Easy, you're using a macro to pick up symbols.
22:40	TimMc	Just like that conversation the other day.
22:40	amalloy	oh, you mean if you specify nil in the clojure spec-thingy
22:41	amalloy	i see
22:41	TimMc	yep
22:41	amalloy	i was trying to find where nil would upset the parsing code, not the spec code
22:42	amalloy	TimMc: a more interesting point that this implies is that you can't parse options like -1, the way head/tail do
22:42	TimMc	Ah.
22:42	amalloy	but i don't think getopt can either; head must roll its own
22:43	TimMc	Can't it?
22:43	TimMc	I have clojopts open, I'll try modifying it.
22:43	amalloy	TimMc: to be clear, i'm talking about 1 as an option "name" (key), not value
22:44	TimMc	yep
22:44	ermnik	how might one add a class to an element in hiccup? Like ckeditor to the text-area element?
22:44	amalloy	[:foo.editor]
22:46	ermnik	from the docs: (text-area name value)
22:46	ermnik	where would [:foo.editor] go?
22:47	ermnik	Or would i be using a more generic element function in hiccup?
22:47	TimMc	amalloy: You and your use of ` outside of macros...
22:47	amalloy	i think you should read the docstring, or possibly the source, for text-area
22:48	amalloy	TimMc: looking back over `man getopt`, i still don't see a thing like "call this function if you see an unrecognized argname"
22:48	amalloy	TimMc: which one are you thinking of? desugar-spec or something?
22:48	TimMc	yeah
22:49	amalloy	well, that's really in a macro anyway
22:49	TimMc	I mean, it reads nicely, but ` still says to me "Oh shit, here comes an s^w^w a macro!"
22:49	amalloy	hahaha
22:50	amalloy	it's just a helper function; not really the same thing as using `(~@x 0) as a shorthand for (concat x [0])
22:50	TimMc	Oh, it's called from a macro, I see.
22:50	adiabatic	what would "an s" be? sexpr?
22:50	ermnik	amalloy: I took your advice... so text-area just returns a vector, second element of which is a map of attributes. should I assoc a :class in there?
22:50	amalloy	$google apostrophe oh shit here comes an s
22:50	lazybot	[Oh shit, here comes an 's'. - Reddit] http://www.reddit.com/comments/65hz7/the_apostrophe_key_does_not_mean_holy_shit_here
22:51	TimMc	adiabatic: http://www.reddit.com/comments/65hz7/the_apostrophe_key_does_not_mean_holy_shit_here
22:51	TimMc	bah, slowternets
22:51	adiabatic	ah, thanks
22:51	TimMc	Bing had no idea what I was talking about.
22:52	amalloy	i'm glad lazybot got it right
22:52	TimMc	I think my trial of that particular search engine is over.
22:52	amalloy	ermnik: i would just take the very simple code text-area contains and replicate it yourself, since it doesn't seem to have a feature for adding anything but an id
22:56	TimMc	amalloy: -1 works fine. desugar calls str on the names, but nil goes to ""
22:56	amalloy	TimMc: but does getopt actually parse it?
22:56	TimMc	amalloy: Yeah, ["-1" "foo"] => {:1 "foo"}
22:57	amalloy	that's pretty amazing
22:57	TimMc	--1 didn't work, of course -- then I fixed my code.
22:59	TimMc	I think I'll bundle that in with some doc fixes.
23:09	technomancy	devn: what does meetup get you over a static site?
23:21	alexbaranosky	devn: I'd also like to know what meetup gets you
23:27	rien	technomancy: findability
23:28	alexbaranosky	so I'm looking into how to add mocking of java methods to Midje -- anyone have any opinions on a good way to approach it?
23:30	alexbaranosky	I envisioned it looking something like: `(fact (doubler ..x..) => "AA" (provided (.toString Object ..x..) => "A") )`
23:31	alexbaranosky	but mostly I'm lost :)