#clojure – 2014-05-14

2014-05-14

00:01	amalloy	shrug i don't know what you've been asked to build. maybe you're not supposed to care where these objects come from, or a transport layer is something you can bolt on later
00:02	ddellacosta	amalloy: (offtopic) didn't you say this exact thing yesterday? http://byorgey.wordpress.com/2009/01/12/abstraction-intuition-and-the-monad-tutorial-fallacy/
00:02	ddellacosta	that's all, just interesting I thought...
00:03	amalloy	ddellacosta: i stole it from him
00:03	ddellacosta	amalloy: well, there ya go
00:04	numberten	is there a good resource for learning how to quickly compile and test files, ideally something similiar workflow wise to testing .hs files by loading them into ghci?
00:04	numberten	leiningen seems rather heavy for that.. but maybe that's just because I'm not especially familiar with it?
00:08	hiredman	numberten: java -jar clojure.jar will start a very bare bones repl
00:08	quizdr	ddellacosta amalloy that's a nice article. i wish more dev bloggers spoke with insight that transcends the "here's a neat trick I just came up with" variety.
00:08	hiredman	numberten: java -cp clojure.jar clojure.main --help will print a list of command line options
00:08	Rosnec	is there a simple way to take two maps, A and B, and for each key that is in both A and B, replace B's key with A's value?
00:08	numberten	hiredman: alright thanks
00:09	Rosnec	I know it wouldn't be too hard with reduce, but if there's something designed for that I'd rather use it
00:09	Rosnec	it should behave something like this:
00:09	amalloy	(merge b a)?
00:10	Rosnec	amalloy, no, not merge
00:10	Rosnec	lemme write an example real quick
00:11	Rosnec	(replace-keys {:a :a-replacement, :b :b-replacement} {:a 4, :b 5, :c 6}) => {:a-replacement 4, :b-replacement 5, :c 6}
00:11	Rosnec	it's the keys I'm changing, not the values
00:12	amalloy	clojure.set/rename-keys
00:12	Rosnec	amalloy: :D
00:12	Rosnec	beautiful
00:14	Rosnec	actually, there's one thing that this doesn't cover in my usage, which might make me resort to writing somethign with reduce
00:14	Rosnec	I need to keep track of which keys I've successfully replaced
00:15	Rosnec	because I'm recursing through a bunch of maps, and each time a key from kmap is used, I want to dissoc that key from kmap
00:16	Rosnec	I suppose I could just check afterwards which keys from kmap exist in map
00:17	Rosnec	and dissoc them when I recur
00:26	technomancy	numberten: once you have a repl open, just run (clojure.test/run-tests) or (require 'some.ns :reload)
00:58	orknob	Is there an archive of this room anywhere? Asking since the room seems to be active outside of my working hours?
00:59	Jaood	the first result of googling "#clojure log freenode" for me
00:59	mdeboard	orknob: The channel logsare indexed by google
01:00	mdeboard	orknob: Also you might want to consider setting up/using an IRC bouncer
01:00	orknob	@Jaood ah, thanks. I searched for
01:01	orknob	@Jaood “freenode archives” and came up with http://www.irclog.org/network.php?net=freenode which doesn’t have Clojure
01:01	orknob	@mdeboard thanks. IRC n00b here. Looking up IRC bouncer.
01:03	technomancy	also, it's IRC, not twitter =)
01:03	danielcompton	Why is clojure.string and clojure.set included with Clojure core but not something like https://github.com/clojure/math.numeric-tower
01:03	technomancy	orknob: ^
01:03	technomancy	danielcompton: historical reasons more than anything else
01:04	danielcompton	technomancy how does it distinguish between them?
01:04	technomancy	danielcompton: I don't understand the question
01:04	danielcompton	technomancy how would I know which is included and which is a separate dependency?
01:05	technomancy	the ones that are included are documented with clojure itself rather than being a separate project
01:08	danielcompton	Got it
01:15	dissipate	anyone else having trouble with http://tryclj.com/?
01:16	cbp`	which troubles?
01:18	dissipate	cbp`, timing out
01:19	cbp`	dissipate: you get Execution timed out! ?
01:20	danielcompton	dissipate working for me
01:20	dissipate	cbp`, yeah, the ajax calls are timing out
01:22	dissipate	hmm, working now.
01:22	dissipate	must have been lagged out
03:38	mskoud	what does (let [{widgets :body} (<! (http/get url))]... specifically the {widgets :body} mean?
03:40	sm0ke	how do i integrate junit tests into my lein project/
03:40	sm0ke	?*
03:41	pyrtsa	mskoud: Given that the right-hand side returns a map m with the key :body, it binds the value (:body m) to `widgets`.
03:42	mskoud	ok, i see, thanks.
03:42	pyrtsa	It's just the ordinary use of maps in let bindings.
03:46	sm0ke	there is a https://github.com/febeling/lein-junit
03:53	hennry	Hello I put the validation on the clojure code if there is error then it will be handle , its reload with the empty form which i not want , what ever data we filled correctly it will be remain in the form and the error field data delete only
03:58	martinklepsch	anyone here some experience profiling with timbre? is it possible to profile across multiple namespaces?
04:43	pbw	Can I use map to create a lazy sequence from two cycles?
04:48	dissipate	pbw, why not use a 'for'
04:48	pbw	Forgot to mention these are infinite sequences
04:49	pbw	Is that implied by "cycle"?
04:49	dissipate	pbw, http://clojuredocs.org/clojure_core/clojure.core/for
04:50	pbw	Digesting that now… thanks
04:53	pbw	I don't know that that will work. I want the map to operate on the corresponding elements of the two (or more) input cycles, not to do nested iterations.
04:53	dissipate	pbw, (take 5 (for [x (cycle [1 2 3]) y (cycle [1 2 3])][x y]))
04:54	dissipate	;(take 5 (for [x (cycle [1 2 3]) y (cycle [1 2 3])][x y]))
04:54	dissipate	;;(take 5 (for [x (cycle [1 2 3]) y (cycle [1 2 3])][x y]))
04:56	dissipate	pbw, not sure exactly what you are trying to do but 'for' will create a lazy sequence from two cycles. :D
04:56	pbw	Yes, but not in the right order.
04:56	pbw	(def cycle2 (cycle [true false]))
04:57	pbw	(def cycle3 (cycle [true true false]))
04:58	dissipate	pbw, and?
04:58	pbw	What I want is a cycle that is the logical and of the corresponding elements of the two cycles.
05:00	pbw	(take 6 (some-map cycle2 cycle3)) => [true false false false true false]
05:08	dissipate	pbw, hmm, looks like my solution is bad actually. :(
05:09	pbw	It's because of the nested iteration of for. It gives a cartesian product of the elements of the input sequences, so it couldn't handle an infinite seq. That's what it looks like to me, anyway.
05:12	pbw	If I try this: (def cycle23 (map and cycle2 cycle3))
05:12	pbw	I get Can't take value of a macro
05:13	jonathanj	#(and %1 %2)
05:14	pbw	That is accepted, but (take 19 (cycle23)) gives: ClassCastException clojure.lang.LazySeq cannot be cast to clojure.lang.IFn
05:15	jonathanj	(take 19 cycle23)
05:15	jonathanj	i don't think you want to call your sequence
05:16	pbw	No, I don't! And that works.
05:16	pbw	(take 10 cycle23)
05:16	pbw	=> (true false false false true false true false false false)
05:16	jonathanj	it's unfortunate that you can't just use `and` as is
05:17	pbw	Ok. Next question. Can I extend this so that it will take more than 1 cycles, rather than just two.
05:18	pbw	It is unfortunate. And that makes it awkward to get my next answer.
05:19	dissipate	pbw, yep, write a function that returns a lazy seq that takes an arbitrary number of cycles as arguments.
05:20	jonathanj	can you define an anonymous function that takes &?
05:20	nathan7	jumblerg: %&
05:20	nathan7	jonathanj*
05:20	dissipate	jonathanj, yep
05:21	ssideris	or just (fn [& stuff] ...)
05:21	nathan7	(#(identity %&) 1 2 3) = [1 2 3]
05:21	jonathanj	<3
05:21	jonathanj	hrm
05:22	pbw	Trying to work out what's going on above.
05:22	dissipate	pbw, set up a multi-arity function the first arity being 2 and the second being arbitrary.
05:22	jonathanj	#(and %&) doesn't quite do what i expected
05:23	pbw	No. => ((true true) (false true) (true false) (false true) (true true) (false false) (true true) (false true) (true false) (false true))
05:23	jonathanj	i guess that's because it's doing (and [true false])
05:23	jonathanj	which is [true false]
05:23	pbw	Ok
05:24	pbw	@dissipate - I'll try that if I can't get a simpler thing working
05:25	jonathanj	i'm not exactly sure how you write this
05:25	dissipate	jonathanj, right, it actually becomes a single argument that is a vector of all the arguments
05:26	dissipate	jonathanj, i think if you add an 'apply' it works
05:26	jonathanj	how do i use the bot? :P
05:26	jonathanj	,(apply #(and %&) [true false])
05:26	clojurebot	(true false)
05:27	jonathanj	,(#(apply and %&) [true false])
05:27	clojurebot	#<CompilerException java.lang.RuntimeException: Can't take value of a macro: #'clojure.core/and, compiling:(NO_SOURCE_PATH:0:0)>
05:27	pbw	I've seen that error!
05:28	dissipate	,(#(apply and %&) true false)
05:28	clojurebot	#<CompilerException java.lang.RuntimeException: Can't take value of a macro: #'clojure.core/and, compiling:(NO_SOURCE_PATH:0:0)>
05:28	pbw	I did get the 2 arg version going a while ago, but forgot how I'd done it. ANd I did try apply.
05:28	ssideris	apply works on normal functions, but and is a macro
05:29	ssideris	hence the error
05:29	dissipate	ssideris, i see. crappy. :( so what's the apply for macros?
05:30	dissipate	http://clojuredocs.org/clojure_contrib/clojure.contrib.apply-macro/apply-macro
05:30	dissipate	says to never use it. :(
05:30	jonathanj	well it is weird
05:30	dissipate	,(#(apply-macro and %&) true false)
05:30	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: apply-macro in this context, compiling:(NO_SOURCE_PATH:0:0)>
05:30	jonathanj	almost as weird as (and) being a macro :P
05:31	emlyn	What about ,(reduce #(and %1 %2) [true false])
05:31	emlyn	,(reduce #(and %1 %2) [true false])
05:31	clojurebot	false
05:33	pbw	It's the unknown number of arguments that is the problem.
05:33	jonathanj	right, so if you: (defn and-fn [& args] (reduce #(and %1 %2) [true false])
05:33	jonathanj	then you can just write: (map and-fn cy1 cy2 cy3 ...)
05:33	emlyn	,(reduce #(and %1 %2) [true false true true false])
05:33	clojurebot	false
05:33	pbw	Duh
05:34	ssideris	pbw: http://clojuredocs.org/clojure_core/clojure.core/every_q
05:34	leggo	though that won't short circuit
05:35	jonathanj	leggo: which? the reduce?
05:35	ssideris	leggo: it stops at the first false it encounters
05:36	ssideris	look at the source
05:36	leggo	it does? how?
05:36	dissipate	http://stackoverflow.com/questions/9218044/in-clojure-how-to-apply-and-to-a-list
05:37	ssideris	leggo: recurs until it finds a false value
05:37	dissipate	,(every? identity '(true false))
05:37	clojurebot	false
05:39	jonathanj	why is `and` a macro?
05:40	dissipate	jonathanj, good question, i have no idea why
05:40	CookedGryphon	jonathanj: so that it can short circuit
05:40	pyrtsa	To avoid evaluating more arguments if the result is already clear.
05:40	Bronsa	jonathanj: so that (and true (println "foo")) short circutis and doesn't print "foo"
05:41	jonathanj	i guess that makes sense
05:41	pbw	(def cyclen (map #(every? identity %&) cycle2 cycle3))
05:41	ssideris	Bronsa: that would be the case for or! or can decide to stop early, but the semantics of and don't allow that, right?
05:41	leggo	ssideris, I must be completely misunderstanding how reduce works then. is it not just a left fold? how would it know when to stop instead of going through all the elements?
05:41	dissipate	ah, makes sense. yep, short circuiting can only truly be achieved as macro
05:41	pyrtsa	(and condition (println "foo")) is a poor example, though. One should use (when condition ...) for it.
05:41	pbw	(take 10 cyclen) => (true false false false true false true false false false)
05:41	Bronsa	ssideris: durr.
05:41	dissipate	in other languages like Python, the arguments must be evaluated first, so it's less efficient
05:41	ssideris	leggo: sorry to have confused you, I was talking about (every?)
05:41	Bronsa	well s/true/false
05:42	pyrtsa	But (when (and ...) ...) makes sense.
05:42	Bronsa	(and false (println "foo"))
05:42	leggo	ssideris ah ok
05:42	ssideris	Bronsa: ok, it makes sense like that :-)
05:43	dissipate	pbw, so it's working?
05:44	ssideris	so and is a macro in order to be able to look at Bronsa's example, evaluate the first thing (false) and stop without evaluating any of the other s-expressions - (println "foo") in this case
05:44	pbw	Yes. Thank you all. Btw, does every? short-circuit?
05:45	pyrtsa	Yes.
05:45	dissipate	ssideris, yes. in a function the arguments must be evaluated (i believe)
05:45	pbw	thanks. What does 'identity' do that makes the %& work?
05:46	dissipate	pbw, it 'unboxes' the arguments from the vector
05:47	pbw	Like 'apply'?
05:47	llasram	pbw: %& is part of the reader syntax for shorter anonymous functions
05:47	sm0ke	i keep getting "java.lang.NoSuchMethodError: clojure.lang.RT.mapUniqueKeys([Ljava/lang/Object;)Lclojure/lang/IPersistentMap;" today
05:47	sm0ke	seen before?
05:47	llasram	,`#(every? identity &%)
05:47	clojurebot	(fn* [] (clojure.core/every? clojure.core/identity sandbox/&%))
05:47	llasram	Er,
05:47	llasram	,`#(every? identity %&)
05:47	clojurebot	(fn* [& rest__49__50__auto__] (clojure.core/every? clojure.core/identity rest__49__50__auto__))
05:48	llasram	Ther ewe go
05:48	Bronsa	sm0ke: using an AOT compiled cljs source against clojure >1.4.0 on clojure 1.3.0
05:48	Bronsa	sm0ke: or compiled against >1.5.0 on clojure 1.4.0, I don't remember when that done
05:49	dissipate	pbw, yeah, like 'apply' it unboxes the arguments from the list/vector
05:49	sm0ke	hurm there is no cljs for sure, must be the second one then
05:54	dissipate	,(and)
05:54	clojurebot	true
05:54	dissipate	,(or)
05:54	clojurebot	nil
05:54	dissipate	pop quiz. why is (and) true?
05:56	pbw	So it will return true if later anded with true?
05:57	dissipate	pbw, yep, put another way, it's because it is the identity of 'and'.
05:57	dissipate	pbw, it doesn't change the result of an 'and'
05:57	dissipate	,(+)
05:57	clojurebot	0
05:57	dissipate	pbw, same reason why (+) is 0
05:58	dissipate	pbw, but i still don't know why (or) is 'nil' and not 'false'
05:58	dissipate	,(or)
05:58	clojurebot	nil
05:58	Bronsa	dissipate: no reason
05:58	CookedGryphon	dissipate: nil is false
05:58	Bronsa	CookedGryphon: false-y
05:58	dissipate	(= nil false)
05:58	llasram	,(identical? false nil)
05:58	clojurebot	false
05:58	CookedGryphon	falsy-y
05:59	Bronsa	dissipate: I guess nil plays nicer with seqs than false
05:59	dissipate	,(and true nil)
05:59	clojurebot	nil
05:59	llasram	Which isn't really a great justification...
06:00	dissipate	why does 'and' evaluate to its first falsy value instead of just 'false'?
06:01	llasram	dissipate: Because it evaluates to the value of the last argument it evaluates
06:01	sm0ke	Bronsa: indeed, bumping clojure version to 1.5.1 in my project seems to have fixed it
06:01	llasram	,(and false 17)
06:01	clojurebot	false
06:01	llasram	,(and true 17)
06:01	clojurebot	17
06:01	sm0ke	but where the hell is that >1.5.0 compiled source is coming from!
06:02	sm0ke	i was using lein-junit and i think its the culprit https://github.com/febeling/lein-junit/blob/master/project.clj
06:02	llasram	sm0ke: Could be any of your deps unfortunately :-( I know Storm messed up that way, at least at one point
06:02	sm0ke	can a dependency be excluded from plugins?
06:02	dissipate	llasram, i see, makes sense
06:03	llasram	sm0ke: Why do you think it's lein-junit?
06:03	dissipate	llasram, but we still don't know why (or) is 'nil'
06:03	sm0ke	llasram: well because lein deps :tree shows clojure 1.4.0 overrwites others
06:04	llasram	sm0ke: Oh, separate problems of someone using version ranges? I misunderstood -- I thought problem was one of your dependencies was AOT compiled and thus implicitly overriding your clojure dep w/ separate AOTed copy
06:05	llasram	dissipate: Yeah, that seems wrong to me -- does seem like it should be `false`. Not that it ever actually comes up
06:05	llasram	I mean, since `or` is a macro, I can't imagine the 0-argument version gets called very frequently
06:08	visof	how can i accumulate the result of recursion on a list?
06:08	visof	i mean the basic way
06:08	Glenjamin	the 0-arity versions should be an identity
06:08	Glenjamin	,(= (or 'x (or)) 'x)
06:08	clojurebot	true
06:08	llasram	visof: `reduce`?
06:08	Glenjamin	that should be true for basically all functions
06:08	Glenjamin	,(= (and (and) 'x) 'x)
06:08	clojurebot	true
06:09	Glenjamin	erm
06:09	Glenjamin	,(= (and 'x (and)) 'x)
06:09	clojurebot	false
06:09	llasram	Glenjamin: I think you may have scrolled back too far :-)
06:09	Glenjamin	oh right, i see
06:10	gyim	llasram: I think the reason for (or)=nil is that (or arg1 arg2 ...) returns the first argument that is not nil/false. So it does not return a logical value (true/false), it returns one of the arguments. And if there are no arguments, there is no reason to return true/false
06:10	Glenjamin	(or) => nil produces an identity, it seemed like the question was hanging :)
06:10	visof	llasram: well, i'm walking on a list if found element matched to another list walk again for this list else element, how can i collect all result?
06:10	llasram	gyim: You know, that makes sense. Good point!
06:11	visof	what i thought: iterate over a list, if element not list return element else walk sublist
06:11	llasram	Glenjamin: Right, but it seemed like the actually-boolean identity value of `false` would have been better, before gyim's suggiestion
06:11	Glenjamin	oh, i see
06:11	Glenjamin	yeah, they're equivalent i guess
06:12	llasram	visof: Example inputs and results? I'm not following
06:18	visof	llasram: https://www.refheap.com/85475 , i know this example like flatten list, but i want to understand teh concept, how can i collect the final result from this code?
06:19	llasram	visof: Well, to start with, you don't use doseq :-)
06:19	llasram	You can call a function recursively from any of the higher-order sequence functions
06:20	llasram	You can usually handle most patterns with `map` etc and/or `reduce`
06:20	jkj	how should i spread io work into multiple workers? ... can't wrap my head around e.g. how to keep 5 futures running
06:20	llasram	visof: Otherwise `loop`/`recur`
06:21	llasram	visof: Without something more specific, I'm not sure what else to add
06:22	llasram	jkj: You can fake it, but IMHO it usually isn't worth it. Just drop down to interop and use the Java standard lib executor service stuff w/ j.u.c queues
06:22	Glenjamin	jkj: i think that's agents or core.async territory
06:22	llasram	jkj: First-class functions makes it far more pleasant to work with than from raw Java
06:23	Glenjamin	i would recommend believing llasram over me in this case, i've only done non-io paralleism
06:24	jkj	llasram: ok. thx
06:24	visof	llasram: so what should the code looks like?
06:25	llasram	visof: What's a specific problem you'd like to solve? Like, just for an example, re-implement `flatten` ?
06:25	visof	yeah but in this shape of code
06:26	llasram	In what sense?
06:27	visof	llasram: the code i pasted, i'll replace doseq to reduce?
06:28	llasram	You've got a few options. You can create something non-lazy using `reduce`. If you want something lazy, you'll need to use explicit recursion with `lazy-seq`
06:29	visof	llasram: so it should be like (reduce conj [] (code)) ?
06:30	llasram	visof: Not quite
06:30	visof	llasram: ?
06:31	llasram	Just a sec... `flatten` is kind of an annoying example
06:37	llasram	visof: flatten just really is not a good example, but here you go anyway: https://www.refheap.com/85476
06:38	TerranceWarrior	is there a way to use clojure as a scripting language or unreal udk 4?
06:39	llasram	visof: Do you have any other example in mind of what you're trying to achieve? Right now it more seems like there's just a technique you want to use, but don't have any particular problems to solve with it
06:39	llasram	Which makes it difficult to discuss
06:39	ssideris	TerranceWarrior: does UDK 4 support java or javascript for scripting?
06:52	TerranceWarrior	ssideris: nope
06:52	TerranceWarrior	ssideris: just c++
07:28	turbopape	Hi guys, I'am trying to put a restart-agent in a set-handler-error! fn, this seems not to be working. is this a known problem, like I'm not allowed to restart inside an agent error handler function ?
07:59	schmir	I'm using clojure.java.jdbc to connect to an 16 year old informix SE database, that's a bit misconfigured. the configured character code page is wrong and I would need a kind of a hook to convert strings to the right encoding. is there a way to do that?
08:10	martinklepsch	when I use dorun to run sth like (map f coll) does this actually also run all map calls that come furhter down the line?
08:21	pbw	schmir: I don't know much about this stuff, but slurp accepts a file encoding argument. java.nio.charset package contains CharsetDecoder and there's a java.nio.charset.spi package for defining charset providers. You may be able to find such a provider for Informix database.
08:28	schmir	pbw: the informix jdbc driver already does the conversion. but the database is itself is misconfigured. thanks for the pointers.
08:34	martinklepsch	when I (dorun something) is that recursive? i.e. when something in there returns a lazy seq, is that also fully eval'd?
08:46	hyPiRion	no
08:47	hyPiRion	,(dorun (list (range)))
08:47	clojurebot	nil
09:02	Raynes	Side effects of waking up at 4AM: you make conch throw exceptions for non-zero exit codes.
09:04	mdrogalis	Heh, morning Raynes.
09:07	hyPiRion	Raynes: no way there's 4 am there now
09:07	Raynes	hyPiRion: Well it's 6AM now.
09:07	Raynes	I didn't say it was easy.
09:07	Raynes	:P
09:08	hyPiRion	oh wow, it really is.
09:09	gfredericks	if you lived in chicago, you'd be home by now
09:09	hyPiRion	gfredericks: Didn't know chicago were in Europe, but yeah.
09:10	gfredericks	chicago is wherever you are most happy
09:10	hyPiRion	clojurebot: chicago?
09:10	clojurebot	Pardon?
09:10	gfredericks	clojurebot: the chicago \|was\| inside you the whole time
09:10	clojurebot	Ack. Ack.
09:11	mdrogalis	You never needed to go to Chicago. The irony is, you're always there.
09:38	_oggy	i want to define a function which takes either one or two arguments (the first one is optional). what's the standard clojure way of doing this?
09:38	mdrogalis	_oggy: Optional args can only go at the end.
09:38	mdrogalis	Maybe take a single parameter as a map.
09:38	_oggy	can i use a multimethod?
09:39	justin_smith	mdrogalis: if it is one or two args you can do the first as optional
09:39	mdrogalis	justin_smith: Yeah, that makes sense. Whenever someone asks for this, I always picture them requesting for something like (f x=42, y) {...}
09:39	justin_smith	,((fn f ([a] (f nil a)) ([b a] [a b])) nil)
09:39	clojurebot	[nil nil]
09:39	justin_smith	,((fn f ([a] (f nil a)) ([b a] [a b])) 1)
09:39	clojurebot	[1 nil]
09:40	justin_smith	,((fn f ([a] (f nil a)) ([b a] [a b])) 1 2)
09:40	clojurebot	[2 1]
09:40	justin_smith	something like that at least
09:42	_oggy	justin_smith: ah, i think i see what you did there :) can i do the same with defn?
09:42	justin_smith	yes, defn is just (def (fn ...)) plus some metadata
09:43	justin_smith	well (def foo (fn ...)) but you get the idea
09:44	_oggy	yup, thanks!
09:44	justin_smith	,(map #(apply (fn f ([a] (f :default a)) ([b a] [a b])) %) [[1] [1 2]]) ; getter example
09:44	clojurebot	([1 :default] [2 1])
09:44	justin_smith	*better
09:51	martinklepsch	I want to run a fn that creates a lazy seq for profiling and I have one toplevel dorun but that does not evaluate lazy sequences further down the line. (thanks hyPiRion) — I guess the easiest way to force complete evaluation would be to print all the elements but that doesn't seem "right"
09:52	martinklepsch	what other options are there for that sort of stuff?
10:05	emlyn	martinklepsch: you could flatten it, or anything else that would walk the whole tree
10:07	justin_smith	emlyn: oh, flatten for side effects?
10:08	justin_smith	,(type (flatten (map #(range %) (range))))
10:08	clojurebot	clojure.lang.LazySeq
10:08	justin_smith	emlyn: that won't work
10:09	justin_smith	if that had forced evaluation, clojurebot would have timed out
10:10	martinklepsch	justin_smith, what else should I do then?
10:11	justin_smith	clojure.walk/post-walk or the likes would be guaranteed to hit everything
10:14	martinklepsch	justin_smith printing everything might also do it, no?
10:15	martinklepsch	here is a bit more context to the problem I'm trying to solve: https://github.com/ptaoussanis/timbre/issues/64#issuecomment-43066222
10:16	justin_smith	martinklepsch: print for side effects just feels yucky
10:17	martinklepsch	justin_smith, yeah sure, just trying to understand better
10:18	justin_smith	change read-file to (comp dorun read-file)
10:18	justin_smith	or (comp doall read-file) if you want the result
10:18	justin_smith	or use doseq instead of map if you don't need the result
10:20	no7hing	what’s the scope of warn-on-reflection if set e.g. in the core namespace?
10:21	justin_smith	,(meta #'*warn-on-reflection)
10:21	martinklepsch	justin_smith: (profile :info :read-file (dorun (map (comp dorun read-file) (take 4 files)))))
10:21	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve var: *warn-on-reflection in this context, compiling:(NO_SOURCE_PATH:0:0)>
10:21	no7hing	and reflections occur in namespaces used by that one?
10:21	martinklepsch	like this?
10:21	nkoza	there is a macro to qualify all symbols in an expression? like (themacro ([hi ho aliastons2/hu {::a 3}])) ;=> '(myns/hi myns/ho ns2/hu {:myns/a 3})
10:21	justin_smith	,(meta #'warn-on-reflection)
10:21	clojurebot	{:added "1.0", :ns #<Namespace clojure.core>, :name warn-on-reflection, :doc "When set to true, the compiler will emit warnings when reflection is\n needed to resolve Java method calls or field accesses.\n\n Defaults to false."}
10:22	no7hing	so it would be global
10:22	justin_smith	no7hing: looks like it is global in scope, not a dynamic var
10:22	justin_smith	yeah
10:22	justin_smith	,`(+ - *) nkoza:
10:22	clojurebot	(clojure.core/+ clojure.core/- clojure.core/*)
10:22	no7hing	visualvm says my application is spending 50% of it’s time on reflection - see no warnings though =/
10:22	justin_smith	nkoza: that is a read macro, not macro
10:23	justin_smith	no7hing: try "lein check" if you are using lein
10:23	no7hing	using it and will do
10:24	justin_smith	no7hing: there are other tricks with reflection on numeric types that are a special case, there is a numeric lib that helps with making sure things are unboxed and numeric reflection is eliminated though ... let me find it
10:24	nkoza	justin_smith: but you can't define a macro with it, (defmacro m [expr] `(~expr)) will not work, I want to qualify the expression before using it in the macro
10:25	justin_smith	,(resolve '+) maybe this?
10:25	clojurebot	#'clojure.core/+
10:25	justin_smith	but that only works for individual symbols
10:25	justin_smith	not expressions
10:28	justin_smith	martinklepsch: well, the outer dorun means you don't need the result right?
10:29	martinklepsch	justin_smith, in that case yes. I actually only care for the result of the profiling
10:30	justin_smith	(doseq [f (take 4 files) _ (read-file f)] nil)
10:30	justin_smith	maybe
10:32	nkoza	justin_smith: resolve also only works with vars
10:36	justin_smith	nkoza: what other than a var would you want to explicitly namespace qualify?
10:36	nkoza	keywords, for example
10:37	martinklepsch	justin_smith, both work. thanks a ton!
10:39	no7hing	justin_smith thanks so far for your help
10:46	justin_smith	,(= ::foo :foo)
10:46	clojurebot	false
10:47	justin_smith	nkoza: the qualified version of a keyword is not equal to the unqualified form
10:47	justin_smith	,::foo
10:47	clojurebot	:sandbox/foo
10:47	justin_smith	,`(:foo) also
10:47	clojurebot	(:foo)
10:50	zeeshanlakhani	probably a stupid question, but am attempting to do a set of async tasks on a request (tasks that I don't need a return value from), my thought was to use futures, but i wanted to see if people would use something else or still use core.async for such an example
10:51	nkoza	justin_smith: I know, but I want to get the ::foo form and qualify it (with the rest of the expression)
10:51	justin_smith	ahh
10:51	justin_smith	to be clear, ::foo is a reader convenience, and it is changed to :ns/foo at read time
10:51	nkoza	justin_smith: basically I need what syntax-quote does but in runtime
10:52	melipone	hi! Is the order guaranteed with pmap?
10:52	justin_smith	nkoza: syntax-quote does not turn :foo into :ns/foo
10:52	clgv	melipone: yes
10:52	nkoza	justin_smith: good point
10:52	justin_smith	nkoza: and the reader makes ::foo into :ns/foo without syntax quote
10:52	melipone	clgv: thanks
10:52	clgv	melipone: but pmap sucks in parallelization if you want to keep your available cores busy ;)
10:53	melipone	clgv: yes, I know, but it works for me
10:54	Glenjamin	reducers/fold also guarantees result order, but not execution order
10:55	clgv	Glenjamin: execution order is not guaranteed with pmap neither
10:56	melipone	off-topic: folks, what's the shortcut in IRC to get the name of the person you want to respond to?
10:56	Glenjamin	really? i thought it just did approximately (map deref (map future coll))
10:56	Glenjamin	with the futures being slightly ahead of the derefs
10:58	nkoza	justin_smith:ok, then maybe I need to walk all the expression doing resolve on each symbol.
10:58	clgv	Glenjamin: pretty close yes. it creates k futures that run in parallel
10:58	clgv	$source pmap
10:58	lazybot	pmap is http://is.gd/98SQJR
10:59	nkoza	justin_smith: thanks for your responses.
11:03	justin_smith	melipone: that is client specific, on my client it is tab
11:06	jcromartie	is there anything like (filter-when x f coll)
11:06	jcromartie	I want to do (if x (filter f coll) coll)
11:06	jcromartie	but in a ->>
11:06	jcromartie	and I don't want cond-?
11:06	jcromartie	I mean cond->
11:10	pyrtsa	I think it'd be hardly readable. Would using as-> be an option?
11:10	stuartsierra	(-> coll (cond->> x (filter f))) ?
11:11	pyrtsa	The question was in a ->>, so I assume it's something like (->> coll (map f) ... ).
11:12	nkoza	jcromartie: what about (-> x (if (filter f coll) coll))
11:12	pyrtsa	Here's a contrived way to achieve it: (->> coll ... (filter (if x f (constantly true)))
11:13	pyrtsa	(Contrived, because obviously the filtering step is extra work in the if-not case.)
11:20	adsisco	I'm follow following the tutorial in the book "Web Development with Clojure", any idea why my /css/screen.css is the default one despite me having already made changes? I've did lein clean and recompile to no avail.
11:24	clgv	,(time (doall (pmap (fn [i] (Thread/sleep (* (- 30 i) 100)) (println i) i) (range 30))))
11:24	clojurebot	#<SecurityException java.lang.SecurityException: no threads please>
11:24	clgv	:/
11:25	clgv	Glenjamin: I tried to verify my sliding window of futures understanding with it. but it just proved it wrong...
11:29	clgv	oh wait chunked seqs..
11:32	clgv	replace (range 30) by (take-while #(< % 30) (iterate inc 0)) ^^
11:36	coventry	clgv: How does chunking affect it? Also confused about why replacing (range 30) with the vector literal [0 ... 29] doesn't change the behavior.
11:38	coventry	Oh, reading the source for pmap makes it clear.
11:39	clgv	coventry: the new aspect I discovered is that #cpu+3 futures are runnning at the same time. from reading the source I thought until now that the number is #cpu+2
11:42	mpenet	no7hing: justin_smith was thinking about https://github.com/ztellman/primitive-math I believe
11:42	mpenet
11:43	clgv	since when does the following throw an exception? &(+ 3.0 3)
11:43	coventry	clgv: What your example suggests to me is that pmap's (map #(future (f %)) coll) will kick off far more futures than you expect in some circumstances because of chunking. That could probably be made a bit smarter.
11:44	cbp	clgv: never ?
11:44	clgv	coventry: yeah that as well. but I tried to verify the "future sliding window of size k" behavior
11:44	clgv	cbp: the primitive-math lib states that ^^
11:45	clgv	oh it doesnt talk of clojure.core/+ I guess...
11:45	cbp	it's the library's yeah
11:48	martinklepsch	if I have an 8 core machine is there some ideal number of threads to run big computations of a queue? or is the best to just test various configurations?
11:49	martinklepsch	(I've previously been told to just test but I'm curious what other people may say)
11:49	cbp	number of cores + 2 seems to be the magic number for some of clojure's internals
11:50	cbp	or was it 42
11:50	cbp	yes test :-)
11:50	melipone	justin_smith: I am using webchat. do u know what it is?
11:52	arrdem	martinklepsch: just test it already
11:53	martinklepsch	arrdem, did you tell me to test it?
11:53	coventry	There are surprisingly few papers about determining the optimal number of threads for a given computation. I guess because it's such a general question that it's hard to say anything useful and specific about it.
11:53	arrdem	(inc coventry)
11:53	lazybot	⇒ 7
11:55	TimMc	martinklepsch: I think the answer also depends on the cache layout, the kernel's scheduler, etc.
11:55	arrdem	workload and hardware factors in addition to OS level details...
12:04	clgv	martinklepsch: well, it depends on your hardware as well. if there is hyperthreading you could use 2*#cpus or only #cpus depends whether your application profits from hyperthreading...
12:04	martinklepsch	clgv, it's a VPS
12:05	clgv	martinklepsch: "#cpus" should have been number of physical cores...
12:05	clgv	martinklepsch: I meant cpu hardware ;)
12:09	gfrederick_s	is there a library that does prn?
12:11	gfrederick_s	if not I might have to make one
12:13	gfrederick_s	more directly I want to make edn extensibly useful within libraries
12:19	no7hing	mpenet, justin_smith: lein check helped a lot and once the culprits where gone uncovered some other issues
12:21	no7hing	now we’ve got another candidate in visualvm, who’s taking up a lot of time: clojure.lang.Symbol.intern
12:23	hiredman	no7hing: are you parsing json or clojure?
12:25	hiredman	no7hing: is visualvm connected to the right process?
12:26	no7hing	hiredman: i’am converting excel files to json, in a rather wasteful way i’ll admit, but we’re wasting that time at unexpected spots
12:26	no7hing	hiredman: https://github.com/mhaemmerle/excel-to-json
12:30	hiredman	no7hing: are you sure you are connected to your running project and not lein's jvm?
12:31	hiredman	no7hing: it looks like you are are generating keywords when converting from excel to json for some reason
12:31	kadodka	/help levers
12:31	kadodka	/help levels
12:32	hiredman	no7hing: don't do that and you'll be fine
12:38	no7hing	hiredman: i triple-checked and i’am really connected to the process in question; here’s a screenshot of the thing http://i.imgur.com/RRKLpC3.png
12:39	hiredman	no7hing: keywords and symbols (keywords are actually backed by a symbol) have some amount of overhead to create, if you want to be really fast stop generating keywords in https://github.com/mhaemmerle/excel-to-json/blob/master/src/excel_to_json/converter.clj
12:41	no7hing	hiredman: are there any alternatives - short of refactoring the code? also asking for another project
12:43	hiredman	no7hing: well, looking at the screenshot, Symbol.intern is not at the top of the list of hot spots
12:43	hiredman	my advice is for if it is
12:44	hiredman	geez, yeah, it is right there in the call tree, keyword -> symbol -> String.intern
12:44	no7hing	hiredman: another view on the data: http://i.imgur.com/qIrzSfl.png - thanks for your help so far
12:45	no7hing	i guess this means back to the drawing board for me
12:45	hiredman	so the same advice, if all you time is spent generating keywords or symbols, and you don't need the semantics of those things, then don't make them
12:45	no7hing	as you see in the code, i’am just switching on them
12:45	hiredman	which you can do on strings just fine
12:46	Raynes	Glenjamin: https://github.com/Raynes/dox First draft.
12:46	no7hing	which i actually might just do, before we refactor the code next
12:46	MarkStang	I have a wrapper I wrote for a Java API, how do I create the same wrapper for a different API? Like an Interface for a Namespace?
12:47	no7hing	fully qualified keywords wouldn’t help either i guess; seems my erlang mindset has bitten me here (where atoms aka symbols are cheap)
12:48	MarkStang	Is there a way to "specify" that or do I just have keep them in-sync
12:48	Glenjamin	Raynes: looks good, might be worth making the message an configuration param
12:48	Glenjamin	conch is neat
12:48	Raynes	What message?
12:48	Glenjamin	the commit message
12:48	Raynes	Ah
12:49	Glenjamin	does conch run the program directly, or via a shell?
12:49	Raynes	Directly.
12:49	Raynes	Hence the shitty glob stuff.
12:49	Glenjamin	yeah
12:49	hiredman	no7hing: they are pretty cheap, but they do enforce certain semantics, the string backing a symbol is interned, keywords are interned so they have reference equality
12:49	hiredman	the machinery to enforce that has a cost
12:50	Raynes	Glenjamin: I actually made some pretty big changes to conch while using it here.
12:50	Raynes	Just this morning.
12:50	hiredman	there is a recent patch (not sure what the status is) for speeding up keyword generation though
12:50	Raynes	Glenjamin: In particular, I got incredibly frustrated because failing commands were just passing by.
12:50	Raynes	So I released a new version that can throw exceptions for non zero exit codes.
12:50	Raynes	Made me incredibly happy.
12:50	Raynes	I'm amazed nobody has bitched about that not being there yet.
12:50	hiredman	MarkStang: there is no way to parameterize a namespace, but you can use multimethods or protocols for polymorphism
12:50	Raynes	I used conch for 5 minutes and wanted it :P
12:52	MarkStang	hiredman: The problem is that all the functions are identical, just the underlying implementation is different. So, the signatures are all identical.
12:54	arrdem	Raynes: nice!
12:54	MarkStang	hiredman: Not sure what I am even looking for... Or what it means to switch between the two implementations? Or how do I switch? Change the "requires" from one to the other?
12:54	hiredman	MarkStang: what is the problem with that?
12:55	MarkStang	hiredman: I am wondering if my architecture is correct, maybe I should be passing in the "namespace".
12:56	hiredman	MarkStang: you would pass some object that you do dispatch on
12:56	hiredman	it really depends what you want
12:57	MarkStang	hiredman: yeah, I think that is my problem, not sure what I want, current design evolved out of implementation... Back to the drawing board...
12:57	Glenjamin	you could even receive a map of {:key fn}
13:01	MarkStang	hiredman: pass in a map of functions or just change the "use" or "requires", it is like I need an object that has a bunch of functions that can be passed around, I wonder if Stuart Sierras components will work here?
13:02	MarkStang	hireman: a stateless object, only functions
13:03	no7hing	hiredman: yeah, been using the keyword in other places as a fun for group-by for example; will look for the patch and still switch to strings
13:03	hiredman	MarkStang: sure
13:07	arrdem	what's the procedure for adding contributors and/or requesting contributor status to a contrib project?
13:10	technomancy	"don't call us; we'll call you"
13:21	arrdem	that's what I thought. kk. forks it is.
13:27	goodgravy	hi all, I’ve a question about the people function towards the bottom of https://github.com/swannodette/om/wiki/Basic-Tutorial
13:29	goodgravy	specifically, the two forms of (update-in x …) followed by x in the mapv – my mental model is that the mapv should just return the original seq unaltered
13:29	goodgravy	because update-in doesn’t change in-place. however, that isn’t the case. can anyone shed some light?
13:30	pyrtsa	There's an if block: (if (:classes x) (update-in ...) x).
13:30	arrdem	goodgravy: right. Update-in returns an altered copy, and mapv is just map forced into a vector.
13:30	pyrtsa	I.e. there is no "update-in followed by x", it's either or.
13:30	goodgravy	ahhhh, OK I see – thanks that’s clear now
14:13	{blake}	So...the iloveponies clojure course has an exercise where you give all the rotations (rotations [a-seq]) of a sequence--e.g. for [1 2 3], ([1 2 3][2 3 1][3 1 2])--and I solved it but I used a nested function that carried a count--inner-rot [a-seq count)--so I could know when to stop. Since preserving state is the next lesson, I don't think that's the solution they were trying to lead me to. Their hint is to use "concat". Any thoughts on how that might be do
14:13	{blake}	ne?
14:15	amalloy	i don't see any obvious solutions that involve concat
14:15	{blake}	Well, that's reassuring. I thought maybe concat with partition?
14:16	{blake}	The whole unit is on recursion, though, and I don't see how you do recursion (without carrying some state) and know when to stop.
14:16	dbasch	well, concat butlast with [first]
14:16	dbasch	sorry, rest with first
14:16	{blake}	Oh, right, that's probably what that is.
14:16	amalloy	{blake}: i would have written https://www.refheap.com/25947cbf86a21575a67a8a3a6
14:17	{blake}	I did...(concat (drop 1 seq2) (take 1 seq2)).
14:17	amalloy	maybe there's something cleverer
14:17	{blake}	amalloy: For loops are next unit. =P I thought about that, too.
14:18	{blake}	It's a lot cleaner. Might just be bad organization.
14:18	{blake}	Yours I mean, amalloy.
14:19	amalloy	{blake}: https://www.refheap.com/8505f3f2524a32dba9e8d503e is another approach, with recursion
14:19	amalloy	`(~@(rest coll) ~(first coll)) is the same as (concat (rest coll) [(first coll)]) but reads nicer imo
14:19	hlship	Has much changed in terms of clojure.main and clojure.repl between 1.5 and 1.6?
14:20	hlship	Some hacks I was using to override clojure.repl/pst that worked in 1.5 aren't working in 1.6
14:20	{blake}	amalloy, yes, that's very close to what I did. (Tho', again, yours is cleaner.)
14:20	llasram	Could use `iterate` too
14:21	amalloy	llasram: iterate is going to be a little awkward, because you need n as a state variable that you don't return
14:21	amalloy	obviously it's possible, but i don't think it reads very well
14:21	llasram	https://www.refheap.com/85491 ?
14:21	amalloy	oh, i see. sure
14:21	{blake}	llasram, No iterate yet. Just conditionals, predicates and direct recursion.
14:21	amalloy	my n is just a silly version of take
14:23	{blake}	llasram, Worth studying, thanks.
14:27	dbasch	{blake}: I’m guessing that for your exercise they meant something like this https://www.refheap.com/85492
14:42	{blake}	dbasch, Maybe, though we have neither "loop" nor "recur" yet!
14:51	dbasch	{blake}: here’s another version with concat and without loop https://www.refheap.com/85494
14:56	{blake}	dbasch, Yep, I'll bet that's it. The solutions have been "map" heavy. Thanks, I'll study that one, too.
14:57	{blake}	I've gotten to where I can come up with A solution for problems, but not necessarily one that feels like I've got any real facility with Clojure.
15:00	dbasch	{blake}: yes, it takes time for the clojurey instincts to start becoming natural
15:00	dbasch	{blake}: sometimes you think you came up with something clever and another person does something cleaner, shorter and more efficient
15:01	{blake}	dbasch, Yeah, and I'm not at the point where I can do anything but goggle at it. =P
15:03	DomKM	What's the purpose of type hinting both the var and args vector? https://github.com/ztellman/clj-radix/blob/master/src/clj_radix/utils.clj#L80-81
15:03	{blake}	There was a unit on evaluating a poker hand, and I had an awful solution (that worked, but still). Then I found:
15:03	DomKM	Do they do different things?
15:03	{blake}	(defn value [hand]
15:03	{blake}	(->> checkers
15:03	{blake}	(filter #((first %) hand))
15:03	{blake}	(map second)
15:03	{blake}	(apply max)))
15:03	{blake}	Took me half-an-hour to figure out how it worked.
15:04	amalloy	{blake}: plz bro. refheap.com. no long pastes in here
15:05	{blake}	amalloy, Sorry! Won't do it again.
15:05	amalloy	DomKM: hinting the arglist provides a version that actually returns a primitive. i'm not sure hinting the var does anything interesting if he's already hinting the arglist, but it might
15:06	DomKM	amalloy: would hinting the var do anything if the args vector weren't hinted?
15:06	coventry	amalloy: Where's that documented?
15:06	amalloy	DomKM: hinting a var with a primitive is usually, as i understand it, not meaningful
15:07	amalloy	{blake}: so checkers is a seq of pairs [f n], where f is a function checking whether a hand qualifies, and n is a number saying how valuable that hand-type is worth?
15:07	{blake}	amalloy, Yeah.
15:08	amalloy	i dunno, coventry. i wouldn't be surprised to hear that the answer is "nowhere", or "in the changelist for clojure 1.3"
15:08	DomKM	amalloy: so is hinting it with a non-primitive meaningful? I was previously only aware of hinting the args vector.
15:08	amalloy	DomKM: yes, definitely
15:08	{blake}	And I'm weak on threading macros; I couldn't figure out what was being passed to what. Also the "second" threw me off.
15:08	amalloy	hinting the arg-vec only became possible in clojure 1.3
15:09	amalloy	hinting the var name was used before that to indicate what object-type a function returned (and functions always had to return an object)
15:09	DomKM	amalloy: ah, thanks
15:09	coventry	amalloy: Oh well.
15:10	amalloy	the arglist hinting syntax was added primarily for functions taking and/or returning primitives, but i don't know what it does when something is hinted as an object type, or when a var is hinted with a primitive
15:10	coventry	{blake}: You can put something like (#(do (println "value after filter" %) %)) in the threading macro arguments, to see what's being passed to what.
15:11	{blake}	coventry, What's the "(#" opener signify?
15:11	coventry	{blake}: It's an anonymous function.
15:11	{blake}	Or, I guess that's "(" followed by "#(".
15:11	{blake}	Duh, right.
15:12	{blake}	coventry, So it just passes the argument through
15:13	amalloy	coventry: http://dev.clojure.org/display/design/Enhanced+Primitive+Support is linked to from the 1.3 changelist. there's also http://dev.clojure.org/display/design/Documentation+for+1.3+Numerics, and i think those two constitute the entirety of official documentation on the topic
15:13	coventry	amalloy: Thanks.
15:38	Norrit	Hi, little question: Is there a function to add an element to a seq at a specific index? (add [0 1 2 3] 1 99) => [0 99 1 2 3]
15:39	justin_smith	,(seq? [0 1 2 3]) (pedantry)
15:39	clojurebot	false
15:40	justin_smith	Norrit: you can assign the value at an index of a vector, or append a vector, or prepend a seq
15:40	Norrit	or vector...
15:40	justin_smith	Norrit: you can make your own insertion function, but there is no clear right way to do it - the others are build in because they have a single simple and fast way to implement it
15:41	Norrit	ok, but I need an add like the one on the java lists
15:41	Norrit	ah, ok
15:42	justin_smith	,((fn [s p e] (concat (take p s) [e] (drop p s))) [0 1 2 3] 1 99)
15:42	clojurebot	(0 99 1 2 3)
15:42	Norrit	building my own one shouldnt be so hard
15:42	justin_smith	that said, the above is straightforward if using seqs is the main target case
15:43	Norrit	thx, I will try that out
15:56	jcromartie	at 6 named params, you should probably just use a map, no?
15:57	llasram	s,6,1, IMHO
16:10	tbaldridge	all parameters should be maps, except that would be horrible for any human to program with, so I'd say use maps as much as can be tolerated.
16:14	amalloy	i wonder, tbaldridge: what would -> and ->> look like, in the world where every function takes exactly one arg, a map?
16:15	amalloy	(i think that's the world you were suggesting, but i'm not sure i read it right)
16:15	tbaldridge	yeah it is a interesting question
16:15	tbaldridge	and yes that was what I was talking about
16:16	tbaldridge	so the idea is, currently (->) has a convention of "first arg". So instead of a positional convention, perhaps a named convention? :first-arg or :coll ?
16:18	hiredman	tbaldridge is advocating a map monad, so you'll need a map monadic bind for composing this functions
16:18	hiredman	I guess that isn't exactly right, but you would want a more powerful function composition
16:19	hiredman	and can functions only return a map? or not? so you have to box values in a map before calling a function
16:19	llasram	Yeah, but the compiler can elide all that
16:19	llasram	Easy-peasy
16:20	hiredman	it is the inverse of a monad really, a map value box goes in, and a value goes out, is that a comonad?
16:20	amalloy	hiredman: i think so, actually
16:21	hiredman	so, a map comonad
16:22	tbaldridge	does it matter what monad it is? :-P
16:23	technomancy	~正名
16:23	clojurebot	If language is not correct, then what is said is not what is meant; if what is said is not what is meant, then what must be done remains undone; if this remains undone, morals and art will deteriorate; if justice goes astray, the people will stand about in helpless confusion. Hence there must be no arbitrariness in what is said. This matters above everything.
16:23	tbaldridge	o.O
16:23	technomancy	https://en.wikipedia.org/wiki/Rectification_of_names
16:24	amalloy	today i learned (a) clojurebot can translate chinese; (b) there's a lot of information in two chinese characters
16:25	hiredman	technomancy flashed those chinese characters in to the optic nerves of the entire conj one year
16:25	technomancy	takahashi method
16:27	whodevil	hello, I'm curious if anyone has any ideas on code style formatting for clojure. This is to make sure all indents and things are consistent in my project. I've seen things like this in intellij for java/groovy, and js-beautify. Is there something like this for clojure?
16:27	llasram	whodevil: Emacs
16:27	whodevil	thank you for your snark, but is there a real answer behind that?
16:28	llasram	whodevil: Well, the "ha ha only serious" that AFAIK Clojure's base indentation style is "whatever Emacs does with Lisp". I'm not aware of any standalone code pretty-printers, but there may be one...
16:29	whodevil	ok, good to know, thanks!
16:30	AimHere	Lisp code style formatting is obvious to anyone who uses Lisp
16:30	sveri	Hi, does someone here know how I can set an attribute in enlive conditionally? When I do something like (do-> (content "foo") (when cond (set-attr :selected true))) I get a NPE in case the condition is not met
16:30	whodevil	AimHere: you are missing the point
16:31	AimHere	What I mean is that all lisp users intuitively agree on the format without thinking about it; for some bizarre reason, there isn't a need for it or for holy wars, as there is in C-style languages
16:32	amalloy	AimHere: "intuitively" there is clearly wrong. most lisp users get it wrong at first, putting trailing parens on their own lines, etc etc, until they post in a forum or irc and the combined wrath of all lispers is focused on them
16:32	llasram	AimHere: I don't believe that's true, even in that more limited form
16:32	AimHere	Name two schools of lisp indentation style
16:33	llasram	Handling of the subsequent sub-forms of a form where the second+ sub-forms are the line following the function-position form
16:33	amalloy	AimHere: people who line subsequent args up with the first arg, and people who indent each line by 2 spaces
16:34	AimHere	See, they don't have a name
16:34	AimHere	Not like 'Whitesmiths' or 'Allmans' or 'K&R' or 'One True Braces' or 'GNU style'
16:34	llasram	Actually, I think they might be "Emacs style" vs "Vim style"
16:35	AimHere	Lisp indentation religious wars haven't been persistent enough to have been named!
16:35	bendlas	Doesn't emacs' clojure-mode use a mixed form with arg alignment as default and 2 space indent for do and def* forms?
16:36	bendlas	I think there is definitely room for a unified indentation library
16:36	whodevil	The reason I'm asking this is that I'm taking on a project with my team that will be written in clojure, some of the people do not have much lisp/clojure experience, so it would be helpful for them to be able to hit "format code" and get the correct code style
16:37	bendlas	whodevil: last time I checked the outlook there was a bit bleak, if not everybody uses the same tool
16:37	sveri	whodevil: the cursive plugin does that
16:37	amalloy	whodevil: technomancy has some incantation to invoke emacs in batch mode and ask it to format a string for you then print it to stdout
16:38	whodevil	I looked into cursive, it seems very promising since my team already uses intellij, but it appears to only be in early access.
16:38	whodevil	amalloy: I'll look into that
16:41	sveri	whodevil: Well, from my point of view it is more useable than the eclipse alternative. regarding editor features it is also preferable to lighttable. However I almost always have a lighttable instance open for the instant repl feature, so a combination of lighttable and cursive works best for me (I am leaving emacs out as I never used it and dont have the time to get adapted to it)
16:41	Frozenlock	Is there a way for compojure to know the scheme when used with nginx?
16:42	Frozenlock	As it is, nginx is dealing with the ssl stuff, and when I check the :scheme in compojure, it returns :http :-(
16:42	Glenjamin	Frozenlock: one sec
16:43	Glenjamin	Frozenlock: i use this behind heroku's ssl terminator
16:43	Glenjamin	https://www.refheap.com/85497
16:44	tbaldridge	whodevil: I've pretty much switched away from emacs to Cursive these days. I highly recommend it.
16:44	Frozenlock	Glenjamin: Oh wow, that might just do it. Thanks!
16:44	Glenjamin	is intellij quite scriptable tbaldridge?
16:45	Glenjamin	Frozenlock: will need something like "proxy_set_header X-Forwarded-Proto $scheme;" in nginx if you don't already have it
16:45	tbaldridge	Glenjamin: I haven't tried. I've mostly been sticking with rebinding keys. That being said, I never really scripted emacs either.
16:46	Frozenlock	Glenjamin: my nginx knowledge is abyssal, so I'm sure it isn't :-p
16:46	Glenjamin	very deep? :p
16:46	Frozenlock	err... Yeah, so deep that I can't get it
16:46	amalloy	Glenjamin: cavernously empty
16:47	TEttinger	Abysmal?
16:48	pandeiro	what happened to the repl error buffer in cider? where did it go and how do i get it back?
16:53	Frozenlock	Glenjamin: It works! Thank you very much :-D
17:02	sveri	so if someone got a tip on enlive I would be happy to get this question answered: https://groups.google.com/forum/#!topic/enlive-clj/IdQavf_Whlc
17:17	jjl`_	is there a convenient reference for all of the clojure sequence protocols, ISeq and such?
17:19	bbloom	~colls
17:19	clojurebot	colls is seqs
17:19	amalloy	i think TimMc has something?
17:19	bbloom	~seqs
17:19	clojurebot	seqs is http://www.brainonfire.net/files/seqs-and-colls/main.html
17:19	bbloom	dammit. i did ~colls last time too
17:20	amalloy	that's the thing i was thinking of
17:21	jjl`_	ta
17:21	amalloy	i'm not sure it actually addresses jjl`_'s question, since it doesn't really discuss the interfaces explicitly
17:22	jjl`_	yeah, i'm actually interested in the differences between the interfaces
17:22	arrdem	if we're gonna do the One True Indenter thing can it at least eat EDN/t.a so that it's useful and built atop sane things rather than being some regex janky in emacs?
17:24	waynr	anyone have advice for getting project info from command line
17:26	arrdem	what kind of info are you after?
17:26	waynr	project name and version
17:26	waynr	currently using awk
17:27	arrdem	so technically there isn't as you'd have to implement a full lisp reader in Awk/Bash which would be a pain.
17:27	bbloom	waynr: is awk getting the job done? if so, stick with that
17:27	waynr	was thinking there might be a leign plugin that spews project map
17:28	waynr	lein*
17:28	gtrak	lein-pprint
17:28	waynr	oh yeah
17:28	gtrak	you could probably abuse cljs+node.js for command-line speed.
17:28	gtrak	it's got a reader.
17:29	gtrak	but if you're running lein-pprint that's moot.
17:29	waynr	lein-pprint will do
17:31	waynr	thanks bbloom arrdem gtrak
17:32	arrdem	waynr: if you need speed it's probably safe to write an awk script that just pulls the first line of the file and matches "(defproject (\w+) \"[^\"]+\"\n
17:34	hlship	... and of course, my problem wasn't Clojure, it was me. Meanwhile, new version of pretty now can filter exception output FTW
17:36	waynr	arrdem: speed isn't important, just wanted to pull project name and version for a continuous integration job
17:39	{blake}	,(first {:a 1 :b 2})
17:39	clojurebot	[:b 2]
17:39	{blake}	,(first {:a 1 :b 2 1 4})
17:39	clojurebot	[1 4]
17:39	{blake}	Huh. In my REPL, the first returns {:a 1}.
17:40	jeremyheiler	maps aren't ordered
17:40	{blake}	But I guess it doesn't matter.
17:40	{blake}	,(first {:a 1 :b 2 :c 3 :q 4 1 4})
17:40	clojurebot	[:q 4]
17:40	bbloom	and things like hashing may change between versions
17:41	{blake}	I thought maybe it was looking for a map key of "1" but that doesn't appear to be the case.
17:41	amalloy	{blake}: it definitely doesn't return {:a 1}. it may return [:a 1]
17:41	{blake}	Yes, vector, sorry.
17:41	jeremyheiler	it actually isn't a vector either
17:42	jeremyheiler	it's a map entry
17:42	amalloy	jeremyheiler: yes it is
17:42	amalloy	map entries are vectors
17:42	jeremyheiler	,(key [1 2 ])
17:42	amalloy	&(vector? (first {:a 1}))
17:42	clojurebot	#<ClassCastException java.lang.ClassCastException: clojure.lang.PersistentVector cannot be cast to java.util.Map$Entry>
17:42	lazybot	⇒ true
17:42	arrdem	,(class (first {1 2}))
17:42	clojurebot	clojure.lang.MapEntry
17:42	amalloy	not all vectors are mapentries, but mapentries are vectors
17:42	jeremyheiler	,(key (first {:a 1}))
17:42	clojurebot	:a
17:42	jeremyheiler	amalloy: ah, sure.
17:42	arrdem	,(source vector?)
17:42	clojurebot	Source not found\n
17:43	arrdem	,(vector? (first {:1 2}))
17:43	clojurebot	true
17:45	{blake}	,(let [victor ["roger" "Roger"]] (vector? victor))
17:45	clojurebot	true
17:45	arrdem	heh
17:46	bbloom	don't call me shirley!
17:46	arrdem	gtrak: does cider/clojure-mode have a folding capability?
17:46	gtrak	I don't think so.
17:46	gtrak	wanna write it?
17:46	gtrak	;-)
17:47	arrdem	gtrak: this summer may be an exercise in writing the bits that need rather than the compiler I planned on :P
17:47	gtrak	just steal some code from org-mode, can't be that complicated.
17:47	arrdem	"can't be that complicated" he said. "just parse the cfg with regexes" he said.
17:48	gtrak	or just reimplement cider as an org-mode extension.
17:48	arrdem	if it means that I can write working org-mode in comments and docstrings...
17:49	cbp	what about docstrings in orgmode syntax
17:51	arrdem	cbp: is this considered a feature or a defect/product of insanity
17:52	cbp	but now you can use org-mode to evaluate examples in docstrings
17:58	Frozenlock	cbp: org-mode's table format already made its way in clojure. What's a little docstring in comparison? :-p
17:59	arrdem	Frozenlock: if it buys us better documentation and easier code reading a docstring's a small price to pay :P
18:00	amalloy	Frozenlock: has it? what's org-mode's table format?
18:00	arrdem	amalloy: \|coll1\|coll\|coll2\|...\|colln\|
18:01	Frozenlock	amalloy: https://groups.google.com/forum/#!topic/clojure/71MEGeYiUKA
18:01	Frozenlock	Searching for the jira request...
18:01	Frozenlock	Ah! Here http://dev.clojure.org/jira/browse/CLJ-1009
18:06	amalloy	Frozenlock: implementation of print-table contains (apply str (interpose divider foo)). does halloway not know about join?
18:07	Frozenlock	That'd be quite surprising
18:08	nullptr	faster than adding the :require, probably
18:12	arrdem	sounds like a cleanup ticket...
18:25	arrdem	we don't have an explicit recursive let structure do we?
18:30	bbloom	Paul Phillips is always entertaining, but i'm never sure if he's entertaining for good or bad reasons .... anyway, i was scrubbing through this video: https://www.youtube.com/watch?v=uiJycy6dFSQ&feature=youtu.be
18:30	bbloom	saw that List(1, 2, 3).toSet() in scala returns false...
18:31	bbloom	b/c apparently that's actually List(1, 2, 3).toSet.apply(()) where () is unit
18:31	bbloom	and unit is not a member of the Set[Int]
18:31	bbloom	madness...
18:41	amalloy	bbloom: i just watched my first paul phillips video this morning
18:41	bbloom	amalloy: he's highly animated
18:42	rlinehan	/join #clojure-pdx
18:43	egghead	lol that video amalloy
18:43	bbloom	which video are you referring to in particular?
18:44	egghead	https://www.youtube.com/watch?v=uiJycy6dFSQ ?
18:44	bbloom	yeah, that's the one i'm scrubbing trhough now
18:53	nbeloglazov	Anyone from clojars team here? Could you help with: https://github.com/ato/clojars-web/issues/208?
18:55	phuu	hey #clojure. I want to get into writing http stuff with clojure (have previously just used cljs) – where best to start? http-kit, or lower level?
18:56	egghead	phuu: depends on what you want to do, I like liberator for http apis
18:56	technomancy	nbeloglazov: sure; taking a look
18:57	phuu	egghead: i want to get a really good understanding of the fundamentals & idioms, so I see the problems the higher level stuff is solving.
18:57	phuu	egghead: seems I could look at ring?
18:57	egghead	ring is just the http model, similar to rack in ruby or wsgi in python
18:58	justin_smith	phuu: yeah, http-kit + ring is a decent place to start
18:58	justin_smith	but you will want a routing lib very quickly
18:58	justin_smith	good idea to try things basic first though
18:59	justin_smith	also ring is extremely modular, so you can start super basic and add middleware as you need features
18:59	justin_smith	which is a much nicer way to do things than config / di / whatevs
19:01	phuu	cool, thanks both
19:05	numberten	can someone explain to me the difference between '(+ 1 2 3) and (list + 1 2 3)
19:05	numberten	I thought these two would be the same but (= '(+ 1 2 3) (list + 1 2 3)) returns false
19:05	gtrak	,+
19:05	clojurebot	#<core$_PLUS_ clojure.core$_PLUS_@16e0d97>
19:05	gtrak	,'+
19:05	clojurebot	+
19:05	cbp	numberten: quote prevents the evaluation of all its arguments
19:06	cbp	numberten: list is a regular function so all of its arguments are evaluated
19:06	numberten	so (= `(~+ 1 2 3) (list + 1 2 3)) should be true?
19:06	cbp	,'(+ (+ 1 2) 3)
19:06	clojurebot	(+ (+ 1 2) 3)
19:06	gtrak	,`~+
19:06	clojurebot	#<core$_PLUS_ clojure.core$_PLUS_@16e0d97>
19:06	gtrak	yes
19:06	cbp	(list + (+ 1 2) 3)
19:06	nbeloglazov	technomancy: thanks, but didn't help for some reason. Will dig into it tomorrow.
19:07	gtrak	numberten: no
19:07	gtrak	it's still quoted, but the first thing is resolved by unquote.
19:07	gtrak	,`(~+ 1 2 3)
19:07	clojurebot	(#<core$_PLUS_ clojure.core$_PLUS_@16e0d97> 1 2 3)
19:07	technomancy	nbeloglazov: the inability to redeploy over an existing version only applies to non-snapshots
19:08	technomancy	so in this case it's probably not a server-side issue
19:08	gtrak	,(eval `(~+ 1 2 3) )
19:08	clojurebot	#<ExceptionInInitializerError java.lang.ExceptionInInitializerError>
19:08	numberten	,(= `(~+ 1 2 3) (list + 1 2 3))
19:08	clojurebot	true
19:08	gtrak	oh, it didn't like that.
19:09	numberten	,(eval '(+ 1 2 3))
19:09	clojurebot	6
19:09	gtrak	interestingly, that doesn't blow up in my cider repl.
19:09	numberten	,(eval (list + 1 2 3))
19:09	clojurebot	#<ExceptionInInitializerError java.lang.ExceptionInInitializerError>
19:09	amalloy	numberten: yes, (= `(~+ 1 2 3) (list + 1 2 3)) should be true
19:09	gtrak	&(eval `(~+ 1 2 3) ) ; try a better bot
19:09	lazybot	java.lang.SecurityException: You tripped the alarm! eval is bad!
19:09	gtrak	heh
19:10	amalloy	&(= `(~+ 1 2 3) (list + 1 2 3))
19:10	lazybot	⇒ true
19:11	numberten	so the '(+ 1 2 3) case leaves the first argument as a symbol
19:11	numberten	and the unquote or the list case refer to the function?
19:12	amalloy	yes
19:13	numberten	does eval run eval recursively on all arguments?
19:13	amalloy	that's not really a good way to describe it
19:13	numberten	hah okay
19:13	amalloy	eval evaluates a data structure as code; the evaluation rules for an object dictate how and whether its arguments are evaluated
19:14	amalloy	eg, in (eval '(+ a b)), then +, a, and b are all evaluated
19:14	numberten	i see
19:14	amalloy	but in (eval '(quote (+ a b))), nothing much is evaluated
19:15	amalloy	in general, (eval 'x) behaves the same as just x
19:15	numberten	so the evaluation rules for a form are to either execute the function in function position with the arguments passed after it. or to find the function associated with that symbol and execute that function with the arguments passed after it?
19:16	numberten	and those evaluation rules treat '(+ 1 2 3) and (list + 1 2 3) the same?
19:16	amalloy	no, '(+ 1 2 3) and (list + 1 2 3) are very different
19:17	amalloy	functions should never be in the function position of a data structure to be evaluated; it should always be a symbol naming a function
19:17	numberten	i thought the only difference was that the first element in the result list of the former is a symbol that refers to the addition function
19:17	numberten	ah
19:17	amalloy	it so happens that, for some functions, it works
19:17	amalloy	but you should always have a symbol, or a list or whatever. something which , when evaluated, yields a function. not something which is already a function
19:24	numberten	would you say it's then better form to quote things that will be evaluated to functions in list
19:24	numberten	for ex: (list '+ 1 2 3) as opposed to (list + 1 2 3)
19:26	amalloy	if you were building something to eval, then the first would be clearly better than the second. not as a matter of form, but of correctness. better still is (list `+ 1 2 3), because who knows, it might be evaluated in a context where clojure.core/+ isn't referred
19:28	numberten	alright thank you
19:44	tolstoy	Anyone know why in OM I might get this when attempting to set-state! [Error] Error: No protocol method IRenderQueue.-queue-render! defined for type null:
19:50	gtuckerkellogg	in my current cider setup (which is pretty brain-dead simple) cider-jump is taking me to files like form-init4938858926778412808.clj, which is obviously not what I want.
19:59	tolstoy	I can't seem to set local component state in Om for some reason. Very odd.
20:01	tolstoy	And now it works. I knew if I type something here I'd get it working. ;)
20:04	{blake}	I wanna condp the count of a seq. For 0 or 1, I want to do one thing. For 2, I want to do something else. For more than 2, I want to do a third thing.
20:06	{blake}	My instinct was to do this as (condp < (count [1 2 3 4]) but that's...not right.
20:08	mange	{blake}: Something like this? (condp >= (count [1 2 3]), 1 :zero-or-one, 2 :two, :more-than-two)
20:08	{blake}	Because I end up saying, essentially, (< count 2) when I want (< 2 count.)
20:09	{blake}	mange: Yeah, I thought I'd flip it but I'm getting an error...
20:09	mange	What error are you getting?
20:10	{blake}	"ClassCastException clojure.lang.Keyword cannot be cast to java.lang.Number "
20:10	mange	What exactly are you running to get that?
20:10	pandeiro	anyone know how i can get cider to show me stacktraces again? feel like i'm programming with a blindfold
20:11	{blake}	Well, let's try it:
20:11	hiredman	,(+ :foo 1)
20:11	clojurebot	#<ClassCastException java.lang.ClassCastException: clojure.lang.Keyword cannot be cast to java.lang.Number>
20:11	hiredman	,(> :foo 1)
20:11	clojurebot	#<ClassCastException java.lang.ClassCastException: clojure.lang.Keyword cannot be cast to java.lang.Number>
20:11	mange	Why are you comparing a keyword with a number?
20:11	{blake}	,(condp < (count [1 2 3 4]) 2 "heh" :else "whoa")
20:11	clojurebot	"heh"
20:11	{blake}	,(condp > (count [1 2 3 4]) 2 "heh" :else "whoa")
20:11	clojurebot	#<ClassCastException java.lang.ClassCastException: clojure.lang.Keyword cannot be cast to java.lang.Number>
20:11	mange	condp doesn't have the :else like cond does.
20:12	mange	If you have an odd number of arguments then the last one is the "else".
20:12	{blake}	mange: Important safety tip. Thanks.
20:12	mange	,(condp >= (count [1 2 3]), 1 :zero-or-one, 2 :two, :more-than-two)
20:12	clojurebot	:more-than-two
20:13	{blake}	So, it's... (> count 2), then (> count :else)...hence the problem.
20:13	mange	Yep. You wouldn't have seen that in the (< count 2) case because it would short circuit before then.
20:15	{blake}	Hmmph.
20:22	gtuckerkellogg	Does anyone else have this problem? in my current cider setup (which is pretty brain-dead simple) cider-jump is taking me to files like form-init4938858926778412808.clj, which is obviously not what I want.
20:22	gtuckerkellogg	It looks like this : https://www.refheap.com/85506
20:28	mange	pandeiro: what do you have cider-popup-stacktraces and cider-repl-popup-stacktraces set to? If either of those is t you should get some stacktraces.
20:39	pandeiro	mange: the former is set to t
20:39	pandeiro	the weird thing is i have no cider-error buffer
20:43	amalloy	{blake}: well, in fairness, you shouldn't really be saying (< (count anything) 2) anyway. it might be infinite, after all!
20:45	Frozenlock	amalloy: Wow, I never thought of that. :-/
20:46	amalloy	Frozenlock: (< (count x) 2) is better written as (not (next x)), for example
20:47	Frozenlock	shame on me https://github.com/Frozenlock/historian/blob/master/src/cljx/historian/core.cljx#L69
20:47	mange	amalloy: I think it depends on the code being written. There are some cases when you can be pretty confident that your sequence will be finite, in which case the count way is much easier to read.
20:49	amalloy	mange: just because it's finite doesn't mean you should count it if you don't care about the count. maybe it's really slow to produce, for example. but (< (count 2) xs) reads as "less than two items in xs". compared to (not (next xs)) reading as "no second item in xs": seems about the same
20:49	mange	If I'm writing a macro I'm not going to use (not (nnext x)), because I have to stop and think about what that's trying to say, whereas (< (count x) 3) is more immediately obvious.
20:49	amalloy	also avoids the problem of gettnig < vs > the wrong way round like {blake} did. it's not immediately obvious to all readers which way those go
20:51	amalloy	mange: if the thing you're counting is a form passed to a macro, you're usually fine, although those can still be infinite
20:51	amalloy	(defmacro foo [] `(manges-macro ~@(range)))
20:51	amalloy	obviously in that case the code is doomed to fail anyway, but it's better to fail than to be stuck counting the inputs forever
20:53	gtuckerkellogg	I see. The whole file needs to be compiled and loaded as the last step for any findable defs.
20:54	mange	amalloy: Yeah, that's a fair call. Somewhat unlikely in practice, but I get what you mean.
20:56	amalloy	mange: interestingly my example was wrong: i can't get any macro to accept an infinite number of arguments
20:56	amalloy	but you can pass a single argument whose size is infinite, and the same thing applies
20:57	noonian	hmm, can't you just do (defmacro foo [& args] ...)?
20:57	noonian	i come into the conversation late
20:57	noonian	came*
20:58	amalloy	noonian: yes, but try actually passing an infinite number of args
20:58	amalloy	with eg, (defmacro bar [] `(foo ~@(range)))
20:58	noonian	well, thats a little different since you aren't even calling the macro
20:59	amalloy	uh. yes you are? when you write (bar), (foo 0 1 2 3 4 5 ...) gets called
20:59	noonian	ah, yes
21:00	noonian	as long as you don't try to consume the entire infitel list you will be fine though
21:00	amalloy	and `(foo ~@(range)) reads as (clojure.core/seq (clojure.core/concat (clojure.core/list (quote dsapi.server.cluster/foo)) (range))), so it's not like the reader is getting stuck. i'm curious who is getting stuck
21:00	mange	noonian: It still doesn't work, even if it's just (defmacro foo [& args] (first args))
21:00	amalloy	noonian: nope. try (defmacro foo [& args] 0)
21:01	amalloy	what you're saying works for functions, but apparently not for macros
21:01	dabd	I want to call a Java method expecting int[] how can I pass it from Clojure? Thanks
21:01	noonian	uh, that worked for me
21:01	dabd	it says Persistent vector can't be cast to I
21:02	amalloy	noonian: you did this, and it worked? (defmacro foo [& args] 0) (defmacro bar [] `(foo ~@(range))), (foo)
21:02	amalloy	wait, it works for me that way
21:02	amalloy	what did i have wrong before?
21:02	dabd	nvm found it: int-array
21:03	mange	amalloy: (bar) at the end, not (foo)
21:03	amalloy	oh, thank you
21:03	noonian	mange: you need to syntax quote the (first args) like '(first args)
21:03	amalloy	good. taht's still broken
21:03	amalloy	noonian: that makes no sense in the context of this discussion
21:03	mange	noonian: No, because args won't exist in the quoted form. We're being passed an infinite list of forms and we want to return the first one as the new code.
21:04	noonian	as i said, i missed the beginning of it and am just trying to make sense of it
21:05	noonian	that makes more sense
21:08	amalloy	mange: i'd love to find out what causes this behavior, even though i never expect to run into it in real life. i don't see any obvious culprits in the compiler
21:08	amalloy	oh wait, i think i see it
21:09	amalloy	macroexpand1 calls Var/applyTo, which delegates to AFn/applyToHelper
21:09	amalloy	in the 20+ args case, that uses seqToArray
21:10	amalloy	because AFn instances don't expect to have more than 20 args - vararg functions usually go through RestFn
21:11	mange	That would do it.
21:13	amalloy	wild
21:13	amalloy	i wonder if that's a bug, or just "dude you're not supposed to do that"
21:14	mange	I'd lean towards saying it's a bug, but I also think you're not supposed to do that.
21:16	amalloy	mange: i found a simple way to prove this is what's going on, by the way
21:16	amalloy	doesn't even need macros
21:16	amalloy	(defn foo [& args] (first args)) (apply foo (range)) returns 0, but (apply #'foo (range)) hangs
21:17	amalloy	i'd say that is clearly a bug
21:17	mange	Yeah, that is far more obviously a bug.
21:18	bbloom	hmm, i'm not sure
21:18	mange	I'm not familiar with Clojure's internals, but I assume that the var dispatches to the AFn method rather than the RestFn?
21:18	bbloom	i ran in to this while working on eclj
21:18	bbloom	there's a question of when arguments are evaluated
21:18	bbloom	and what it even means to "evaluate" a lazy argument list
21:22	amalloy	mange: well, AFn has a static helper, and RestFn doesn't. rather, clojure functions like (fn foo [& args]] ...) extend RestFn and provide an implementation
21:22	amalloy	so the var uses AFn's helper to decide which arity of the function it's wrapping to call
21:23	amalloy	but that helper can't cope with non-realized args
21:23	narayana_	hello i am new in clojure i wish ask one thing about internal stuffs in clojure
21:24	narayana_	how can i load other deps dynamic
21:25	narayana_	when i don't having lein
21:25	narayana_	sorry for my bad english
21:26	justin_smith	narayana_: alembic can find and bring in dependencies at runtime
21:26	justin_smith	https://github.com/pallet/alembic
21:28	mange	amalloy: That sounds like a slightly different, but closely related, bug, then? So at least two places assume the argument list is finite (one in macro expansion, one in var dispatch)?
21:28	amalloy	mange: no, just vars
21:28	amalloy	macroexpansion goes through the var
21:28	mange	Ah, okay. That makes more sense.
21:28	bbloom	this seems to hang my repl: (eval (list* first (range)))
21:28	narayana_	that is not what i am thinking sometimes on my tablet i just running repl
21:29	bbloom	it's not even a sensible expression, i meant to write foo there
21:29	bbloom	heh
21:29	amalloy	bbloom: well, the result is infinite, so if you're trying to print it...?
21:29	amalloy	oh wait
21:29	bbloom	,(eval (list* first [5 10 15]))
21:29	mange	bbloom: It does seem like the evaluation time is a bit "flexible", which is troubling when any of those arguments could perform side effects.
21:29	clojurebot	#<ExceptionInInitializerError java.lang.ExceptionInInitializerError>
21:30	bbloom	mange: yeah.. but.... if you want your side effects to occur in a particular order, use let or do
21:30	bbloom	yes, clojure promises left to right evaluation of arguments... but only b/c it's implemented that way
21:30	bbloom	i assume anyway
21:30	amalloy	bbloom: isn't that trying to run (first 0 1 2 3 4 ...)? that fails for exactly the same reason that (apply first (range)) does
21:30	amalloy	which is that it goes through AFn, not RestFn (since first isn't a RestFn)
21:31	amalloy	another close cousin of the defect i just discovered
21:31	bbloom	amalloy: right. i was just exploring in the repl & i had to kill my lein proc b/c of it
21:31	amalloy	bbloom: emacs master race. i just use C-c C-c to stop execution
21:32	bbloom	amalloy: does that talk to the jvm on another thread?
21:32	mange	"Both the operator and the operands (if any) are evaluated, from left to right", https://clojure.org/evaluation
21:32	bbloom	b/c it definitely doesn't work in my terminal
21:32	mange	Left to right is guaranteed by this page (which is as close to a spec as I know of).
21:32	amalloy	bbloom: i dunno. i use swank. maybe that doesn't work anymore in cider
21:33	amalloy	mange: the JLS also makes this guarantee, so it was reasonable enough for clojure to follow in those footsteps
21:33	mange	But that's not true with respect to infinite argument lists, because they could be evaluated in whatever order.
21:34	mange	Well, not actually, still left to right, but not before evaluation.
21:34	amalloy	it must use another thread, i guess, because what happens is i get a ThreadDeathError
21:34	bbloom	amalloy: ah yes, ThreadDeathError
21:34	bbloom	which you apparently need to catch and rethrow anywhere you have a (catch Throwable ...)
21:34	dabd	I'm trying to call some Java code from Clojure. The Java code reads a file which is a resource in the jar and it works fine. When I call the Java code from jar it can't find the file. Could this be a problem with classpaths? Thanks
21:35	bbloom	(catch Exception ...) isn't general enough and (catch Throwable ...) is TOO general
21:35	bbloom	:-/
21:35	mange	So the function can be called before its arguments are evaluated if they're in a lazy sequence, which goes against the page talking about evaluation order.
21:35	dabd	I mean to write: When I call the Java code from clojure it can't find the file
21:35	bbloom	mange: thanks for the "evaluation" page reference
21:36	bbloom	amalloy: i'm wondering if there is a way to trick the implementation in to calling eval on the first 20 arguments, but not the remaining
21:36	bbloom	eg if there are side effects
21:36	amalloy	bbloom: what Errors do you think you should be catching?
21:37	bbloom	amalloy: like in a test framework or something
21:38	bbloom	amalloy: http://docs.oracle.com/javase/7/docs/api/java/lang/AssertionError.html
21:38	bbloom	seems like a useful non-Exception-subclass
21:38	amalloy	bbloom: fine, but those should be caught separately, in the particular cases you want to catch an assertion. you don't want to catch all Errors generally
21:39	amalloy	(try ... (catch Exception e ...) (catch AssertionError e ...))
21:39	amalloy	there are way more Errors you don't want to catch than those that you do
21:39	bbloom	amalloy: either way i have to enumerate some special cases either to permit ThreadDeath to pass or to capture assertions
21:39	amalloy	so i wouldn't worry about the fact that ThreadDeathError is one you don't want to catch
21:39	amalloy	bbloom: for sure
21:39	amalloy	and it's the second case. enumerate the special case of things you want to catch
21:40	bbloom	i mean, i dunno.... there's also IOError and a bunch of other weird random things. see list: http://docs.oracle.com/javase/7/docs/api/java/lang/Error.html
21:41	bbloom	seems to me that ThreadDeath shouldn't exist at all
21:41	bbloom	just kill the bloody thread
21:41	amalloy	bbloom: right, and you don't want to catch any of those either
21:42	amalloy	i don't know what throws IOError, having never received one in my life, but it's a lot more serious than IOException and i wouldn't try to catch it
21:42	bbloom	fair enough
21:42	bbloom	anyway: more interesting is the question of argument eval beyond 20
21:43	amalloy	i remember way back in the day i used ThreadDeath for flow control
21:43	cbp`	wat
21:44	amalloy	implementing an automaton thingy of my own, with psuedo threads. i threw ThreadDeath myself to indicate that one of those threads was done
21:44	amalloy	so thoroughly misguided
21:45	TerranceWarrior	anyone looking for a clojure programmer as an intern or for $15 an hour(i have over 20 years in many other software programming languages).
21:45	amalloy	this would be in like 2007
22:02	srruby	I am new to core.logic. In core.logic I try (fd/+ a b c 10) and I get an arity exception. (fd/+ a b 10) works. Any ideas? Thanks, John
22:09	dabd	I need to find the last occurence of a string within a large string. What is the fastest way to achieve this?
22:09	dabd	Actually i need the index of the last occurence
22:10	nullptr	(.lastIndexOf haystack "needle")
22:10	nullptr	,(.lastIndexOf "haystack" "y")
22:10	clojurebot	2
22:10	dabd	oh so simple thanks!
22:36	tmciver	Could someone explain to me the difference between using 'lein install' and 'lein localrepo install ...'?
22:38	mange	tmciver: it looks like 'lein install' installs the current project to the local maven repository; 'lein localrepo install' installs a specified jar to the local repo with a given groupId, artifactId and version
22:41	tmciver	mange: hmm, not sure I understand. What if you tell localrepo to install a version that's not the project's current version, i.e., a previous version?
22:42	mange	With localrepo you have to provide an actual jar file. With 'lein install' it will take the project you're currently in, compile it, put it in a jar and install it to the local repo.
22:43	tmciver	mange: OK, that doesn't seem very useful to me :) but people seem to be using localrepo so I guess it is.
22:43	mange	To make 'lein localrepo install' do the same thing as 'lein install' you'd have to do something like 'lein jar && lein localrepo install target/jarName.jar group/artifact 0.1.0'
22:43	mange	localrepo lets you install jars that you don't own into your local maven repo, which then means you can include them in a lein project.clj file and have them added properly.
22:44	tmciver	mange: ah ha! Now I see it's utility. Thanks.
22:44	tmciver	s/it's/its
22:44	mange	No worries!
22:51	tomjack	"java.lang.AssertionError: Assert failed: (every? (comp identity :id) %) at clojure.tools.cli$compile_option_specs.invoke(cli.clj:241)" :)
23:03	dgleeson	hello, I'm pretty new to clojure. I have a vector filled with maps, I'd like to iterate over the vector and put the maps into a core.async chan. I'm struggling trying to figure out how to loop over the vector. Can someone give me a hint?
23:05	tomjack	(core.async/onto-chan ch the-vector)
23:05	justin_smith	also, in the more general case, using a map where a seq is expected will give you [key, value] pairs
23:06	justin_smith	,(map identity {:a 0 :b 1 :c 2})
23:06	clojurebot	([:c 2] [:b 1] [:a 0])
23:06	justin_smith	oh, wait
23:06	justin_smith	you are talking about a vector of maps
23:06	justin_smith	,(map :a [{:a 0} {:a 1} {:a 42}])
23:06	clojurebot	(0 1 42)
23:07	dgleeson	tomjack: oh cool, I was making that way harder than it should have been
23:08	dgleeson	this is the data structure I got back from this rest client I'm using. It seems weird that it would return a vector. I think I'm still not sure exactly why I would use a vector over a list.
23:09	dgleeson	I have [{:node "node name"} {:node "other node name"}]
23:09	dgleeson	except the vector might have 20,000 maps in it
23:09	dgleeson	which is why I chose to look into core.async
23:10	dbasch	dgleeson: the only reason to use a list is if you need to insert elements in the front
23:11	dbasch	dgleeson: if you may need to do random access, you definitely want a vector
23:12	dgleeson	interesting
23:13	justin_smith	dgleeson: you can use a vector pretty much anywhere you would use a list
23:13	justin_smith	dgleeson: and for this reason the standard json libs return vectors
23:27	storme_	Is it bad practice to call functions from a macro?
23:29	dgleeson	ok, so now I have my maps onto my channel, is there an easy way to loop read until the channel is closed?
23:31	dgleeson	something like (while !nil ( do-some-stuff (<!! chan )))
23:31	dgleeson	?
23:36	dgleeson	I think I just need to read through this core.async walkthrough again :P
23:36	egghead	dgleeson: :p
23:37	egghead	go-loop and when msg should do it
23:46	l1x	dgleeson: depends how you would like to process it but there are two significantly different ways, the lazy and the eager way (there is something in between when part of the sequence is eager)
23:46	akurilin	For the linux/ubuntu folks among you, do you have a trick from switching between two java versions installed side-by-side on the same machine?
23:46	l1x	akurilin: http://askubuntu.com/questions/315646/update-java-alternatives-vs-update-alternatives-config-java
23:47	l1x	,(doseq [n [{:nodeA 1} {nodeB 2}] ] (println n))
23:47	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: nodeB in this context, compiling:(NO_SOURCE_PATH:0:0)>
23:47	l1x	,(doseq [n [{:nodeA 1} {:nodeB 2}] ] (println n))
23:47	clojurebot	{:nodeA 1}\n{:nodeB 2}\n
23:47	akurilin	l1x: okie dokie
23:48	l1x	,(for [n [{:nodeA 1} {:nodeB 2}] ] (println n))
23:48	clojurebot	({:nodeA 1}\n{:nodeB 2}\nnil nil)
23:48	l1x	dgleeson: see the difference?
23:49	l1x	i guess it is not trivial first but the later is producing a lazy-seq
23:49	akurilin	l1x: man that was simple, I can't trust something that works that nicely
23:49	akurilin	where's the pain?
23:49	l1x	hahahaha
23:49	l1x	akurilin: sorry to disapoint
23:52	l1x	i spent the entire day trying to figure out how to deal with kafka iterator in Clojure but no luck, if anybody wants to help here is the question http://stackoverflow.com/questions/23668308/what-is-the-correct-way-of-using-kafka-iterate-in-clojure
23:52	akurilin	So to go from clj 1.5.1 to 1.6 I just need to update the version in my project file and lein will take care of the rest?
23:53	devn	hmph, maybe this is REPL or AWS SDK related, but... I have a pending atom (def pending (atom 0)), and then I have a progress-listener, which increments the pending atom when the event is :started, and decs it with it's :completed. The odd thing is, the inc in the :started event never seems to fire on the /first/ event. It works fine for all subsequent events.
23:53	devn	Meaning I always end up at -1
23:53	l1x	akurilin: yes
23:53	l1x	where is the pain again?!
23:54	devn	i've hidden it, in my codebase
23:54	l1x	:))
23:54	l1x	devn: can you show the code?
23:58	l1x	devn: https://gist.github.com/l1x/596baf96f000299f30db