#clojure – 2014-12-27

2014-12-27

01:02	sova	(* 2 3)
01:02	clojurebot	suffusion of yellow
01:02	sova	Hahah
01:02	pcn	That makes me so happy
01:02	pcn	Let's everyone get a watch
01:03	pcn	an i ching calculator watch
01:03	sova	clojurebot can perceive colors
01:03	pdk	after that i'm feeling pretty suffused
02:24	TEttinger	(doc map)
02:24	clojurebot	#<AccessControlException java.security.AccessControlException: access denied ("java.lang.RuntimePermission" "accessDeclaredMembers")>
02:24	TEttinger	hiredman, any ideas on what's causing that?
02:38	hiredman	I moved the sandbox over to a new host, upgraded the version of clojure to the latest 1.7-alpha, looks like 1.7 uses some more permissions when just loading the clojure runtime
03:20	profil	Why does a swap! with a map return the entire atoms value? just like this https://clojuredocs.org/clojure.core/swap!#example_542692d5c026201cdc32709f
03:21	thearthur	profil: I'm under the impression that the return value of swap! is only ever the contents of the atom in question
03:21	thearthur	,(doc swap!)
03:21	clojurebot	"([atom f] [atom f x] [atom f x y] [atom f x y & ...]); Atomically swaps the value of atom to be: (apply f current-value-of-atom args). Note that f may be called multiple times, and thus should be free of side effects. Returns the value that was swapped in."
03:22	thearthur	the reason it does this (if im understanding yoru queston) is do you can thread the swap through other expressions and have them use the new value
03:23	thearthur	(-> my-atom (swap! assoc :a 1) :a inc dec)
06:20	__cskksc__	:q
06:27	__cskksc__	It is possibly a noob question. Can I use (reset! some-atom @other-atom) in a fn after (for ...) ? So in all (fn (for ....) (reset! ....))
06:27	__cskksc__	It does not seem to work. But if do a reset by itself in repl, it works fine.
06:29	thheller	for is lazy, probably better to doseq if you don't need the result
06:31	__cskksc__	Ah, thanks so much. It worked.
06:32	__cskksc__	Had'nt considered the laziness of (for)
08:12	SagiCZ1	bbloom: really like your article about Code Density, I am in the situation you describe and I am glad I am probably not as stupid as clojure makes me feel sometimes
08:15	luxbock	SagiCZ1: link to article?
08:15	SagiCZ1	http://www.brandonbloom.name/blog/2013/06/24/code-density/
08:16	luxbock	thanks
08:56	hellofunk	SagiCZ1: i liked that article but i feel like it took me about twice as long to process reading it as compared to, say, a 100K line Java project
09:02	perplexa	mmmh..
09:33	__cskksc__	I'm getting an error between for and doseq. Can anyone please help? http://pastie.org/9800710
09:34	justin_smith	__cskksc__: well, you won't get the error with for, because for won't even run the code, since the result isn't used
09:36	justin_smith	__cskksc__: it seems like somewhere your [] got turned into a (), and you can do assoc-in on a ()
09:37	__cskksc__	Okay yeah it will create a lazy sequence. for works fine in repl though. So i thought if I force eval using doseq it'll work.
09:37	justin_smith	I think it's because somewhere grid or next-grid is being turned into a lazy-seq where it used to be a vector
09:37	justin_smith	you can't assoc-in on a lazy-seq
09:38	justin_smith	that's what that error is saying
09:38	__cskksc__	justin_smi: Thanks :) .Getting back to it.
09:39	justin_smith	also, this style of code isn't the best use of clojure. I think you'll find that rewriting to a functional style will be more clear, and also faster.
09:40	__cskksc__	You mean I could do it without a atom ?
09:40	justin_smith	right, and without globals in general
09:42	justin_smith	I don't see anything in your code that would turn the game state into a lazy-seq, but I still think that is the cause of the error
09:43	__cskksc__	ah okay, ill try doing it without game-state in var.
09:43	justin_smith	__cskksc__: the translation will likely be tricky at first, you may want to solve your current issue before undertaking it
09:45	__cskksc__	justin_smi: yeah. im very new to clojure and functional programming in general :)
09:46	justin_smith	the general "big picture" of it is that you translate the code so that any globals accessed become arguments to the function, and any globals modified become part of the return value
09:47	justin_smith	and then you'll often end up using higher order constructs like map or reduce to describe a series of updates, propagating the results via return value
09:50	__cskksc__	yeah
09:51	justin_smith	also, as a little stylistic thing, a cond with only one condition is better expressed as "when", and a cond with only two conditions is better expressed as "if"
09:54	hellofunk	justin_smith: except that with if there is one test, while a cond with two exprs can have 2 different tests, no?
09:55	justin_smith	hellofunk: I am referring to __cskksc__ 's pasted code, where he uses (cond (q? x) y :otherwise z)
09:55	hellofunk	justin_smith: ok
09:55	justin_smith	hellofunk: of course for that generalized case you still want cond, but he never uses it that way
10:13	__cskksc__	justin_smith: Yeah you're right. an 'if' makes more sense there.
10:16	SagiCZ1	i want to have two optional parameters with zero default values, is this correct?
10:16	SagiCZ1	[x & {:keys [mag acc] :or {mag 0 acc 0}}]
10:17	luxbock	SagiCZ1: yep
10:17	justin_smith	SagiCZ1: that works, but seriously consider not using varargs keyword params, they are tricky to use
10:18	justin_smith	it's much easier to just take an optional map, that makes composing with other functions easier
10:18	SagiCZ1	i think i saw this kind of usage all over seesaw for example
10:19	SagiCZ1	isnt this an optional map?
10:19	justin_smith	SagiCZ1: it's optional key value pairs
10:19	justin_smith	[x & [{:keys ...}]] would be an optional map
10:19	SagiCZ1	i see.. then the user has to put { } around the params right?
10:20	justin_smith	&((fn [& {:keys [a b]}] (+ a b)) :a 1 :b 2)
10:20	lazybot	⇒ 3
10:20	justin_smith	&((fn [& [{:keys [a b]}]] (+ a b)) {:a 1 :b 2})
10:20	lazybot	⇒ 3
10:20	justin_smith	exactly
10:20	justin_smith	but keeping things in a map is actually convenient in many ways
10:21	SagiCZ1	cool.. didnt know its better
10:21	hellofunk	SagiCZ1: plus if you want defaults, you can just merge the arg map onto a defaults map, any args provided will overwrite the defaults
10:23	SagiCZ1	hellofunk: and i would do that in the funciton body right?
10:23	hellofunk	SagiCZ1: yes
10:24	SagiCZ1	thanks
10:24	hellofunk	SagiCZ1: you might be able to destructure it as well, but i think the body is easier personally
10:29	SagiCZ1	how does this work?
10:29	SagiCZ1	&(#(read-string (str 2 \r %)) "101010101")
10:29	lazybot	⇒ 341
10:30	SagiCZ1	&(#(read-string (str 2 %)) "101010101")
10:30	lazybot	⇒ 2101010101
10:30	Bronsa	,2r101010101
10:31	clojurebot	341
10:31	SagiCZ1	ohh..
10:31	Bronsa	SagiCZ1: it's the radix syntax
10:31	SagiCZ1	so its a clojure literal?
10:31	Bronsa	2rXXX means XXX in base 2
10:31	Bronsa	yeah
10:31	SagiCZ1	thats clever
10:31	Bronsa	3r23
10:31	Bronsa	,3r23
10:31	clojurebot	#<NumberFormatException java.lang.NumberFormatException: For input string: "23">
10:31	Bronsa	,3r22
10:31	clojurebot	8
10:31	Bronsa	etc
10:31	SagiCZ1	thank you
10:32	Bronsa	there's also
10:32	Bronsa	,1e4
10:32	clojurebot	10000.0
10:32	hellofunk	and, this time of year, it's nice to catch up with r&r too
10:32	hbccbh	,4r3e2
10:32	clojurebot	#<NumberFormatException java.lang.NumberFormatException: For input string: "3e2">
10:32	hbccbh	,4r3.2
10:32	clojurebot	#<NumberFormatException java.lang.NumberFormatException: Invalid number: 4r3.2>
10:33	masnun	,(+ 1 1)
10:33	clojurebot	2
10:33	justin_smith	it's too bad that doesn't work
10:33	justin_smith	,(* 4r32 0.1)
10:33	clojurebot	1.4000000000000001
10:33	justin_smith	not as nice
10:33	clojurebot	No entiendo
10:35	tephra	is it worth getting clojure coockbook given that I already have programming clojure?
10:35	SagiCZ1	cockbook?
10:36	tephra	oops soory
10:36	hellofunk	tephra: each clojure book is a different point of view. absorb them all if you have time and interest
10:38	tephra	hellofunk: thanks, someone told me that it was unnecessary but given that I get it for free i think it should get it then :)
10:39	SagiCZ1	tephra: cant harm
10:39	hellofunk	and how do you get it for free? tephra
10:40	tephra	got a free ebook from oreilly
10:41	hellofunk	tephra: you have the oreilly clojure book by chas and christophe right?
10:41	luxbock	https://github.com/clojure-cookbook/clojure-cookbook
10:42	tephra	hellofunk: yeah programming clojure right? got it when we used clojure in school a year ago, chas, brian and christophe
10:42	SagiCZ1	clojure in school? wow
10:42	tephra	oh it's clojure programming
10:43	SagiCZ1	yeah its a diffrence
10:43	tephra	yeah i got that one (clojure programming)
10:44	SagiCZ1	me too.. liked it
10:44	tephra	SagiCZ1: in our programming language and paradigms course we used it to learn functional programming
10:44	SagiCZ1	tephra: good teachers then..
10:44	tephra	yes it's very good
10:45	tephra	SagiCZ1: yes very good, my latest course is learning distibuted and parallel programming in erlang with joe armstrong :)
10:46	SagiCZ1	what school is this?
10:46	bbloom	SagiCZ1: luxbock: glad you guys enjoyed the article! thanks
10:47	tephra	SagiCZ1: stockholm university
10:47	SagiCZ1	bbloom: hi, you're welcome!
10:47	SagiCZ1	tephra: hah maybe i should finish my masters there
10:48	hlprmnky	So I'm trying to run a REPL inside a Docker container from library/clojure:latest - I have cider-nrepl 0.8.2 as a dependency in my project and in my ~/.lein/profiles.clj (so, one on each side of the host/container divide)
10:48	tephra	SagiCZ1: unfortunetly we don't have any comp sci masters
10:48	tephra	:(
10:48	hlprmnky	both are running Leiningen 2.5.0, on Java 1.7.0 (the minor versions of the JDK do differ)
10:48	SagiCZ1	what about cybernetics?
10:48	hlprmnky	and when I try to connect, I get this:
10:49	hlprmnky	Connecting to nREPL at 127.0.0.1:12345
10:49	hlprmnky	SocketException The transport's socket appears to have lost its connection to the nREPL server clojure.tools.nrepl.transport/bencode/fn--7462/fn--7463 (transport.clj:95)
10:49	hlprmnky	I do know that the REPL session is listening on 12345, and that the port is forwarded to the host (verified with 'docker port')
10:50	tephra	SagiCZ1: no sorry, the master is in computer and system science but no programming. security, data mining and bussiness inteligence
10:50	hlprmnky	The last time I ran into an issue in bencode it was because I had leiningen 1.x on one side and 2.x on the other, but that's not the case here
10:50	SagiCZ1	i see
10:50	hlprmnky	google hasn't been super illuminating, I'm hoping someone else here has been in a similar situation and fixed it. :)
10:50	tephra	SagiCZ1: I'm thinking of getting my master from Uppsala since they actually do computer science. Just have my bachelor thesis left :)
10:57	SagiCZ1	tephra: me too, good luck!
10:59	tephra	SagiCZ1: same! where do you study?
11:02	SagiCZ1	in Prague
11:29	SagiCZ1	how can i get and remove random element from a vector?
11:30	SagiCZ1	,(remove #{3} [1 2 3 3 4 5])
11:30	clojurebot	(1 2 4 5)
11:30	SagiCZ1	i need to remove only one.. not all the duplicates
11:31	SagiCZ1	i will probably have to work with indexes
11:32	AimHere	Well stepping through the collection with loop/recur is an option here
11:32	andyf	SagiCZ1: Do you plan to eventually remove all elements from the vector? If so, you could shuffle it, then pop one element at a time from the end
11:32	masnun	,(set [1 2 3 3 4 5])
11:32	clojurebot	#{1 4 3 2 5}
11:33	andyf	efficiently
11:33	SagiCZ1	andyf: its complicated.. i need to go through the collection one element at a time and decide if i want to keep it or not
11:33	AimHere	,(set [1 2 3 3 3 3 4 5
11:33	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading>
11:34	AimHere	,(set [1 2 3 3 3 3 4 5])
11:34	clojurebot	#{1 4 3 2 5}
11:34	andyf	You can either use the built-in vectors, and then removing an element takes linear time, or use core.rrb-vector, where removing an element can be done in log n time.
11:34	hellofunk	SagiCZ1: really depends if you are removing from a specific location (index) in the collection or if you are removing based on a predicate
11:35	SagiCZ1	i dont know how to explain it
11:36	hellofunk	SagiCZ1: well, index vs. predicate should be a simple decision
11:36	SagiCZ1	i just need to go through all of the element.. i dont care about order
11:37	hellofunk	sounds like you are removing based on a predicate
11:37	hellofunk	unless it truly is random
11:37	SagiCZ1	it doesnt have to be random
11:37	AimHere	So each time you pick an element you reduce the number by one? Couldn't you have a map of value counts using frequencies, and just decrease the value of that map by one each time that predicate comes up?
11:38	andyf	Here is one way to remove an element at a specified index from a vector, returning a vector, taking linear time: (defn remove-elem-i [v i] (vec (concat (subvec v 0 i) (subvec v (inc i)))))
11:38	AimHere	Then rebuild the collection with some sort of homegrown invert-frequencies function
11:38	SagiCZ1	AimHere: no, sometimes i decide not to remove the element so the count stays the same, then i need to move on the next element.. as if increasing index by one
11:39	AimHere	What's the main goal here? It sounds like there might be an x-y problem going on
11:39	SagiCZ1	i am implementing iterative optimization described here http://www.cs.cmu.edu/afs/cs/project/jair/pub/volume4/fisher96a-html/node8.html#SECTION00032000000000000000
11:40	SagiCZ1	i have a collection of n clusters consisting of some number of points.. i need to go through all the points and try to re-assign them to a different cluster if it would improve the overall cluster fitness
11:45	AimHere	My first instinct for something like that would be to use reduce or loop to go through the cluster and rebuild the original cluster without the reassigned ones
11:46	SagiCZ1	i will try some loop magic thanks for ideas
12:10	hellofunk	can unquote-splice be used outside the context of a macro or eval?
12:10	justin_smith	absolutely
12:10	hellofunk	i.e. this works: (eval `(~@(list + 1 2 3))) but this does not: (+ `(~@(list 1 2 3)))
12:11	justin_smith	hellofunk: you just have to use it in a way that makes syntactic sense
12:11	hellofunk	well (+ 1 2 3) is valid syntax, so why doesn't (+ `(~@(list 1 2 3))) do as i'd expect?
12:12	justin_smith	because (+ (1 2 3)) isn't valid
12:12	justin_smith	and that's what you are generating
12:12	hellofunk	ah, i'm getting jumpled in my nesting
12:13	justin_smith	,(apply + `[1 2 3 ~@[4 5 6]])
12:13	clojurebot	21
12:13	justin_smith	note how the inner coll is spliced into the one above it
12:13	hellofunk	justin_smith: i can't use apply since i'm actually trying this on ->
12:13	justin_smith	OK
12:14	justin_smith	outside of eval / macros ~@ can only generate a list
12:14	hellofunk	i was thinking i'd could splice into the parent form
12:14	justin_smith	right, yeah, outside a macro that's not really going to work
12:19	arrdem	where is there a good writeup on nREPL middlewares?
12:26	hellofunk	justin_smith: i guess the issue is that backquote must always be followed by a paren, you cannot use ~@ with a ` alone
12:26	SagiCZ1	andyf: thank you for that element removing function, i build the algo around that, its nasty but pretty short and works, thanks
12:26	SagiCZ1	(inc andyf)
12:26	lazybot	⇒ 16
12:31	justin_smith	hellofunk: well, paren or some other nesting pair (my example used [])
12:32	justin_smith	&`[1 2 ~@{:a 0 :b 1}]
12:32	lazybot	⇒ [1 2 [:b 1] [:a 0]]
12:33	justin_smith	&`["test" ~@#{1 2 3}]
12:33	lazybot	⇒ ["test" 1 3 2]
12:38	AdmiralBumbleBee	a note, O'rielly is offering a free ebook, one of the choices is 'Clojure Cookbook'
12:38	AdmiralBumbleBee	http://post.oreilly.com/rd/9z1zsko8rq94drpmmfel8vj0u6drolp2ihbcme9uljg is the link
12:38	maxigas	rly?
12:38	maxigas	wow cool
12:38	AdmiralBumbleBee	yes
12:39	AdmiralBumbleBee	java performance, the definitive guide is an option too
12:39	AdmiralBumbleBee	which is an excellent book that's helped my clojure programming a lot.
12:40	maxigas	heh i tried to register and got this
12:40	maxigas	Error: time_in_future.
12:40	AdmiralBumbleBee	yeah, it appears to be having issues at the moment
12:40	justin_smith	yeah, I got that error when I logged in
12:40	AdmiralBumbleBee	just refresh
12:40	AdmiralBumbleBee	it works eventually
12:42	maxigas	AdmiralBumbleBee: true
12:42	maxigas	but
12:42	maxigas	AdmiralBumbleBee
12:42	maxigas	http://libgen.org/book/index.php?md5=3f6bc98349b3d776640ba6215fc8d9d8
12:42	maxigas	^^^ clojure cookbook is already liberated by pirates
12:43	maxigas	:P
12:45	kl	how does racket compare to clojure?
12:46	justin_smith	it uses it's own vm - uses less memory, not as fast, is able to tree-shake for generating smaller executables
12:46	justin_smith	has less default usage of immutable / persistent datatypes (though it does have them if you look for them)
12:47	justin_smith	also, racket is part of a system designed for teaching programming
12:47	justin_smith	while clojure is more pragmatic, industry oriented (relatively speaking)
12:50	justin_smith	library interop w/ clojure is via the jvm, and is totally transperent (there is no translation / compatibility layer needed), library interop in racket will be with C libs, and requires ffi wrappers
13:16	justin_smith	hellofunk: here's a weird one ##`{:a 0 ~@[:b 1] ~@[:c 2 :d 3]}
13:16	lazybot	⇒ {:c 2, :b 1, :d 3, :a 0}
13:16	justin_smith	hellofunk: to see why it is weird, try taking one of those splices out
13:46	SagiCZ1	how do i split coll into n equal parts?
13:46	arrdem	partition
13:46	arrdem	$grim clojure.core/partition
13:46	lazybot	http://grimoire.arrdem.com/1.6.0/clojure.core/partition
13:46	SagiCZ1	thats splitting it into m n-sized parts
13:48	arrdem	#(partition (/ (count %2) %1) %2), use a real function if you want to assert that %2 divides (count %1) exactly.
13:48	SagiCZ1	arrdem: thanks
13:50	maxigas	hmmm Continuous Enterprise Development in Java is not on libgen
13:50	SagiCZ1	,(#(partition (/ (count %2) %1) %2) 3 (range 10))
13:51	clojurebot	()
13:57	arrdem	##(count (range 10))
13:57	lazybot	⇒ 10
13:58	SagiCZ1	,(#(partition (/ (count %2) %1) %2) 3 (range 12))
13:58	clojurebot	((0 1 2 3) (4 5 6 7) (8 9 10 11))
13:58	SagiCZ1	,(#(partition-all (/ (count %2) %1) %2) 3 (range 10))
13:58	clojurebot	((0 1 2 3) (4 5 6 7) (8 9))
14:00	sveri	Hi, is there a way to evaluate every function of a namespace in cursive when it is connected to a repl? All I found is how to load the complete file and then evaluate every form separately
14:03	sveri	Hm, I just saw that load file does that, seems like I have a different error in my workflow, nevermind
14:12	hellofunk	##`{:a 0 ~@[:b 1] ~@[:c 2 :d 3]}
14:13	lazybot	⇒ {:c 2, :b 1, :d 3, :a 0}
14:13	hellofunk	man how many of these bots do we have for syntax eval.
14:13	hellofunk	##`{:a 0 ~@[:b 1]}
14:13	andyf	,(count (available bots))
14:13	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: available in this context, compiling:(NO_SOURCE_PATH:0:0)>
14:14	hellofunk	justin_smith: so the core clojure reader for syntax takes precedence over the reader macros for syntax quote and unsplicing
14:14	andyf	syntax quote is part of the Clojure reader
14:15	hellofunk	andyf: indeed but the map form is read as having too few args before the splicing of the reader has a chance to do its thing... even though the backquote is actually read before the map
14:16	hellofunk	justin_smith: so i concur with you, that is indeed weird
14:17	hellofunk	does anyone regularly run emacs and cider on a running web app on a remote server via ssh?
14:27	maxigas	http://libgen.org/book/index.php?md5=e2d9cadb117ce286f7dae2667158ba84
14:27	maxigas	^^^ Continuous Enterprise Development in Java: Testable Solutions with Arquillian
14:34	Hamled	Can someone explain to me why
14:34	andyf	maxigas: Is this relevant to a discussion, or you like to post links to books that have been pirated?
14:34	Hamled	##(= (short-array [1]) (short-array [1]))
14:34	lazybot	⇒ false
14:35	augustl	Hamled: see: Java :)
14:35	andyf	Yeah, for the same reason that .equals returns false for those two things in Java
14:35	Hamled	okay
14:36	Hamled	hmm
14:36	andyf	Clojure's = is true if two immutable values are equal, or if they are not immutable, then if Java .equals is true for them. There may be a few exceptions to that statement, but I think not many.
14:37	maxigas	andyf: sorry it was quite offtopic, now that you made me think about it
14:39	andyf	Java docs for equals method says "The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any non-null reference values x and y, this method returns true if and only if x and y refer to the same object"
14:39	andyf	Other classes can override that default, but perhaps Java arrays do not.
14:41	andyf	Hmm. The docs for the Java Arrays class says that two short arrays are .equals if they are the same length and have equal elements, so now I don't know why you got false ...
14:43	justin_smith	hellofunk: I avoid lein in production, not to mention cider / emacs
14:43	andyf	ah, (java.util.Arrays/equals ...) would return true, but that is a static method in class java.util.Arrays, not the one that you get from doing regular .equals method
15:05	Frozenlock	hellofunk: I do. (cider, emacs, running app, ssh.... )
15:08	kl	justin_smith: thanks for that response re: clojure vs racket there earlier
15:09	kl	Hmm. I can't help but feel I'd absolutely love clojure if it was statically typed.
15:10	kenrestivo	cough core.typed cough
15:11	kl	kenrestivo: I've not seriously looked at it - but is it not a hack, or somehow otherwise badly implemented / ill-advised?
15:12	dnolen_	kl: it's based on Typed Racket research
15:12	kl	That is interesting
15:14	profil	thearthur: but it says, "Returns the value that was swapped in.". Shouldnt that mean ":a 1"?
15:14	profil	thearthur: re swap!
15:23	dnolen_	kl: The biggest difference between Clojure & Racket is that Clojure is a production oriented language that targets the JVM & JavaScript and goes out it's way to work well on those hosts, with host libraries, and with host tooling. If these platforms matter to you & you like Lisp then the other factors are considerably less important.
16:08	augustl	anyone using something other than compojure to path match for liberator?
16:08	augustl	I fancy myself a path matcher that isn't a list essentially a list of regexps :)
16:13	heeton	Having trouble doing this idiomatically. How do I update values inside a tree? https://gist.github.com/heeton/aafd06e63bfb847f57f6
16:13	heeton	I've tried to dig into zippers but am finding them a bit opaque :)
16:17	augustl	heeton: generally I prefer to not store tree structures as deep data structures matching the tree structure, but store by reference instead. I.e. something like {1 {:type "foo" :children [2 3]} 2 {:type "foo"} 3 {:type "foo" :children [4]} 4 {:type "bar"}}
16:17	mearnsh	need a pointer getting this macro to expand recursively (see the last cond case). L11 shows the behaviour i'm looking for: https://www.refheap.com/95469
16:17	augustl	heeton: I like my trees shallow :)
16:19	heeton	augustl: not sure how I could simplify my structure unfortunately, any suggestions?
16:19	heeton	(Massive noob here btw)
16:19	heeton	(And probably still too stuck in OO mode)
16:20	augustl	heeton: maybe something like {1 {:type "plots" :children [2 3]} 2 {:type "wat" :contains nil} 3 {:type "wat" :contains nil}}
16:20	augustl	the downside is of course that invalid states are representable
16:21	TEttinger	:pre conditions may be handy
16:21	augustl	heeton: or if your tree doesn't need to be ordered you can store it as {:plots {1 {:contains nil} 2 {:contains nil}}} and run update-in
16:21	augustl	and assoc-in
16:22	heeton	The plots are ordered
16:22	TEttinger	ordered maps may come in handy, there's that lib called ordered
16:22	TEttinger	$google ordered clojure
16:22	lazybot	[flatland · GitHub] https://github.com/flatland
16:22	heeton	TEttinger: thanks, will have a look
16:23	TEttinger	https://github.com/flatland/ordered/tree/develop
16:24	mearnsh	hm, i realize i can just call macroexpand inside my macro
16:24	TEttinger	mearnsh, sounds like wizardry
16:24	heeton	Hypothetically, if I were to reference plots (using a let block or something) and then use update-in on it, will that affect the atom? Or am I creating a copy of the variable or something? (Apologies if naming is slightly wrong)
16:24	TEttinger	update-in returns a new coll
16:24	mearnsh	TEttinger: cf these: https://www.refheap.com/95469 https://www.refheap.com/95470
16:24	TEttinger	to update an atom, you use swap! or reset!
16:25	TEttinger	(doc swap!)
16:25	clojurebot	"([atom f] [atom f x] [atom f x y] [atom f x y & ...]); Atomically swaps the value of atom to be: (apply f current-value-of-atom args). Note that f may be called multiple times, and thus should be free of side effects. Returns the value that was swapped in."
16:25	TEttinger	(doc reset!)
16:25	clojurebot	"([atom newval]); Sets the value of atom to newval without regard for the current value. Returns newval."
16:25	augustl	heeton: well at any point if you read from the index and then tell the atom to write to that index, you're unsafe since the atom might have changed in the meantime
16:25	heeton	TEttinger: that'll set the value of the overall atom though right? I'm wondering if I can access nodes inside it in the same way
16:25	augustl	s/read from the index/read an index/
16:26	augustl	for advanced stuff I would have considered just having some kind of atomic ref and writing my own code that maybe used an executor..
16:26	TEttinger	you may want refs if you want to be sure about multiple transactions overlapping
16:26	heeton	Hmm, so I'm really confused then. What's the recommended way of getting to my goal? I've got my application state which has a few pieces of data, one of which is a list of plots. I'd like to update those.
16:27	heeton	I might just bring plots out to be it's own atom
16:27	TEttinger	plots as in graves or plots as in graphing calculator stuff?
16:27	TEttinger	or action movie "plots"
16:28	heeton	Haha, let's assume graves here :)
16:28	heeton	Actually for keeping track of plants
16:28	heeton	So a plot is a map that has some keys like "planted-at" "contains" etc.
16:29	TEttinger	,(let [state (atom {:plots [[1 2][1 5]]})] (update-in @state [:plots 0 1] inc))
16:29	clojurebot	{:plots [[1 3] [1 5]]}
16:29	TEttinger	,(let [state (atom {:plots [[1 2][1 5]]})] (do (update-in @state [:plots 0 1] inc) @state))
16:29	clojurebot	{:plots [[1 2] [1 5]]}
16:30	TEttinger	as you can see, it doesn't change after just calling update-in, but...
16:30	TEttinger	,(let [state (atom {:plots [[1 2][1 5]]})] (swap! state update-in [:plots 0 1] inc))
16:30	clojurebot	{:plots [[1 3] [1 5]]}
16:30	TEttinger	,(let [state (atom {:plots [[1 2][1 5]]})] (do (swap! state update-in [:plots 0 1] inc) @state))
16:30	clojurebot	{:plots [[1 3] [1 5]]}
16:31	TEttinger	swap! will change the value of the atom at later reads
16:31	heeton	Ok, thanks, will crack on with it :)
16:31	TEttinger	but most of clojure's collection fns will return new collections (with shared state for efficiency)
16:32	mearnsh	ok, i solved my problem - my code was right, just forgot about macroexpand-all
16:32	TEttinger	oh, and if you want to add something, you can do something like
16:33	TEttinger	,(let [state (atom {:plots [[1 2][1 5]]})] (do (swap! state update-in [:plots 2] (constantly [3 4])) @state))
16:33	clojurebot	{:plots [[1 2] [1 5] [3 4]]}
16:33	TEttinger	,(let [state (atom {:plots [[1 2][1 5]]})] (do (swap! state update-in [:plots 3] (constantly [3 4])) @state)) ;; I can't remember if this works, indexes that are larger than the size
16:33	clojurebot	#<IndexOutOfBoundsException java.lang.IndexOutOfBoundsException>
16:49	dnolen_	is it possible to set the plugins classpath for leiningen?
16:49	dnolen_	curious about running AOTed plugins
16:50	dnolen_	update my exploration on making cljsbuild run faster http://swannodette.github.io/2014/12/22/waitin/
16:50	dnolen_	basically you can make cljsbuild start 5X faster w/ all my tweaks
16:50	dnolen_	so 1 second to run (and do everything) instead of 5.5 seconds
17:00	hellofunk	cool stuff. i've never been sensitive to a few extra seconds that others complain about with clj and now you say cljs, but dramatic engineering is still captivating to ponder
17:10	justin_smith	Bronsa: maybe you can provide some more insight to this SO question about a failed type annotation? It clearly has something to do with the destructuring, but it would be cool to know more of the details of why that failure happens. http://stackoverflow.com/questions/27671638/why-is-this-type-annotation-failing
17:12	justin_smith	augustl: that structure is known as an adjacency list representation by the way, and it is great because it bridges the gap between cyclical data structures and immutable data, without any laziness hacks
17:13	Bronsa	justin_smith: I don't have a SO account but ^double is an array type hint, [4 5 6] is not an array
17:13	Bronsa	justin_smith: invoking it as (dot3 (double-array [4 5 6]) (double-array [1 2 3])) would do what he expects
17:14	dnolen_	hellofunk: the startup time is fine for REPL based stuff, it's serious bummer for tooling - things you run at the command line
17:15	Bronsa	justin_smith: uhm no, nevermind. let me read that better
17:15	justin_smith	Bronsa: actually it doesn't
17:15	justin_smith	I tried that first :)
17:15	hellofunk	dnolen_: is the performance boost to lein cljsbuild auto for speeding up each automatic compilation? So if it took 1 sec before when you save a file, now it takes much less?
17:16	justin_smith	I think it is some compiler optimization that kicks in (the IFN$OOD inner class) but the destructuring makes it compile in a faulty way?
17:16	Bronsa	justin_smith: I can't reproduce on my repl?
17:16	dnolen_	hellofunk: this is about speeding up incremental compilation, that's already fast
17:16	dnolen_	hellofunk: it's been fast forever
17:16	justin_smith	Bronsa: with warn-on-reflection and hotspot both enabled?
17:16	dnolen_	hellofunk: "this is NOT about speeding up incremental compilation"
17:17	Bronsa	justin_smith: ah.
17:17	Bronsa	justin_smith: it's a bug I fixed that's committed in 1.7 I believe
17:17	justin_smith	Bronsa: https://www.refheap.com/95471
17:17	Bronsa	justin_smith: https://github.com/clojure/clojure/commit/85169b785c5dd59e89c0bd12600eebe5f6172874
17:17	justin_smith	aha, cool
17:17	Bronsa	that would explain why in my repl it works fine
17:18	Bronsa	justin_smith: http://dev.clojure.org/jira/browse/CLJ-887 yup the error seems the same
17:19	justin_smith	very nice to have a decent explanation, thanks
17:19	justin_smith	(inc Bronsa)
17:19	lazybot	⇒ 81
17:20	justin_smith	that is way too low
17:20	justin_smith	(inc Bronsa)
17:20	lazybot	⇒ 82
17:23	Bronsa	i wounder how hard it would be to make c.c/destructure understand array type hints
17:23	Bronsa	wonder*
17:23	Bronsa	probably not that hard
17:23	justin_smith	that would be nice
17:36	SagiCZ1	how do i make an inverse matrix and matrix determinant in incanter?
17:37	SagiCZ1	or should i use clojure.core.matrx?
17:43	SagiCZ1	oh i guess inverse is called solve in incanter.. so silly
18:05	gfredericks	having a hard time not getting this error when switching to java 8; look familiar?
18:05	gfredericks	Unable to resolve classname: ..proxy$java.lang.Object$SignalHandler$d8c00ec7
18:06	Bronsa	gfredericks: no idea but try applying http://dev.clojure.org/jira/browse/CLJ-979
18:06	justin_smith	gfredericks: I have never seen that
18:07	gfredericks	I wonder if this is a problem with namespaces named .
18:09	justin_smith	gfredericks: I was always surprised that a namespace named . would even work
18:09	gfredericks	turning off my user profile made it work so that might've been it
18:09	gfredericks	the "..proxy" part made me wonder
18:18	TEttinger	oh my god do I need to make another gfredericks meme
18:18	augustl	trying out bidi for the first time. Why does (match-route ["/foo/bar" :bar "/" :root] "/foo/bar") return {:handler :bar} and (match-route ["/" :root "/foo/bar" :bar ] "/foo/bar") nil? I expected both to return {:handler ;bar}
18:22	augustl	Figured it out. Seems the vector should only have two items in it.
18:24	justin_smith	yeah, it looks like for multiple routes you want a vector with parent on the left, and a tree (map) of all child routes on the right
18:27	dnolen_	cfleming: fwiw, just encountered the issue again with cljs/closure.clj, all core symbol cannot be resolved
18:33	TEttinger	gfredericks: justin_smith: https://dl.dropboxusercontent.com/u/11914692/gfredericks.png was the first, now there's https://dl.dropboxusercontent.com/u/11914692/gfredericks_on_namespaces.png
18:33	Kristien	lol
18:34	justin_smith	(inc TEttinger)
18:34	lazybot	⇒ 34
18:34	TEttinger	gfredericks is like the corner case detective
18:35	TEttinger	if there is a minute crack in the facade that is reliable software behavior, gfredericks will apply a liberal dose of plastic explosive
18:37	Bronsa	(inc TEttinger)
18:37	lazybot	⇒ 35
18:40	akkad	thank you all for making this language soo welcoming
18:40	Hamled	Is there something about the way I've written this test that would cause it to pass even though its condition definitely fails (I can see that when I evaluate it directly) http://hastebin.com/fumiwavixo.clj
18:40	justin_smith	Hamled: you don't call is
18:40	justin_smith	only test/is can cause failures
18:41	Hamled	oh lol of course )
18:41	Hamled	thanks
18:41	TEttinger	akkad, glad the community is welcoming! so, you're welcome!
18:41	justin_smith	very common mistake, there is a lein plugin called eastwood that will tell you when you have problems like that
18:41	akkad	compared to years of #lisp yes. :P
18:41	TEttinger	heh
18:41	TEttinger	who makes eastwood again?
18:41	Hamled	justin_smith, ah cool I think I saw eastwood before but wasn't sure what it was for
18:41	augustl	akkad: just making up for the bad error messages, that's all
18:42	Bronsa	(inc andyf) ;; TEttinger
18:42	lazybot	⇒ 17
18:42	justin_smith	"you're more welcoming than #lisp" is kind of like "it tastes better than earwax"
18:43	TEttinger	(inc justin_smith)
18:43	lazybot	⇒ 163
18:43	Hamled	oh lol I have eastwood in my plugin list I just never thought to use it :D
18:43	TEttinger	damn your karma has gotten significant
18:49	justin_smith	somehow it has. most of the people I end up helping don't even know how karma works
18:51	cfleming	dnolen_: Ok. Closing and reopening the file doesn't work, right? Are other symbols from other files resolved correctly?
18:51	dnolen_	cfleming: yes they are
18:52	dnolen_	cfleming: and no closing/reopening doesn't work
18:52	cfleming	dnolen_: Well that's really weird. Next time it happens can you send a screenshot, and I'll see if I can see anything unusual?
18:52	dnolen_	cfleming: sure thing
18:53	augustl	liberator is such awesome, wow
18:55	SagiCZ1	justin_smith: how does karma work? i started to feel stupid inc'ing everyone who helped, so i rarely do it now which makes me feel a little bad.. like not apprecienting the help enough
18:58	justin_smith	SagiCZ1: it's totally informal
18:59	justin_smith	nothing to feel bad about, or to gloat about
18:59	SagiCZ1	so its just a little fun thing...
18:59	justin_smith	SagiCZ1: meant it as in they don't even use the karma commands
18:59	justin_smith	yeah
19:00	SagiCZ1	oh so otherwise there is something like karma on IRC? maybe thats why it doesnt confuse me
19:01	SagiCZ1	i started with IRC only because of #clojure
19:01	justin_smith	it's a convention, various channels have bots that keep track of informal karma
19:01	justin_smith	usually via nick++
19:02	SagiCZ1	i see
21:00	thearthur	,(let [a (atom 0)] (swap! a inc))
21:00	clojurebot	1
21:01	thearthur	profil: yes you are right the atom it's self is not returned by swap. Could you link ot the context where it was seeming to do so
21:20	gfredericks	justin_smith: my java 8 . problem was apparently caused by putting (ns .) in my [:repl-options :init]
21:20	gfredericks	swapping it out for (create-ns '.) fixes it
21:21	gfredericks	(YOLO)
21:21	justin_smith	haha
21:48	gfredericks	,(try (re-pattern "\\R") :java-8 (catch Exception e :java-7))
21:48	clojurebot	gfredericks: No entiendo
21:48	gfredericks	&(try (re-pattern "\\R") :java-8 (catch Exception e :java-7))
21:48	lazybot	java.lang.SecurityException: You tripped the alarm! catch is bad!
21:48	gfredericks	,(re-pattern "\\R")
21:48	clojurebot	#"\R"
21:48	gfredericks	&(re-pattern "\\R")
21:48	lazybot	java.util.regex.PatternSyntaxException: Illegal/unsupported escape sequence near index 1
22:13	richardlevan	Hey guys, I’m trying to learn core.async. In a tutorial, I can do the following in a let statement:
22:13	richardlevan	(let [c (chan)]
22:13	richardlevan	(go (>! c "hello"))
22:13	richardlevan	(assert (= "hello" (<!! (go (<! c)))))
22:13	richardlevan	(close! c))
22:13	richardlevan	But if I say (def c (chan)) then (go (>! c “hello”)) it fails. Can someone explain why?
22:15	nuwanda_	what do you mean by fails?
22:15	richardlevan	I get a big stack trace as a result
22:16	richardlevan	I have [org.clojars.trptcolin/core.async "0.1.242.1"] in :dependencies in my project.clj, and I used (require '[clojure.core.async :as async :refer :all]) to get core.async
22:19	richardlevan	Hm, seems pretty quiet here. Anyone know where else I could get help?
22:23	richardlevan	Hey I don’t use IRC often. Am I doing this right? Why are people joining and leaving but no one is speaking?
22:24	andyf	Sometimes people leave automatically because their computer shuts down, or their network connection gets disconnected. They aren't necessarily doing anything manually for it to happen. Same for joining -- for some people it happens automatically when their network connection is restored.
22:24	richardlevan	oh ok thanks
22:24	andyf	Not everyone joined to the room is paying attention right now. Most probably are not.
22:25	richardlevan	Do you know a place where I’d be more likely to get help for my question?
22:25	andyf	Here, next week :)
22:25	richardlevan	haha, yeah I guess Saturday night is a bad time :P
22:25	andyf	Well, Saturday night not always so much like this -- but this is the week between Christmas and New Year's, so lots of people are on unusual schedules and doing other things.
22:26	richardlevan	Ah yeah that makes sense too. Cool, I’ll come back here again in the future
22:26	andyf	You could send a message to the Clojure Google group, or if there is one specifically for core.async, there.
22:27	andyf	You are more likely to get help if you include as many details about what you are doing, and error messages you are seeing, as you can.
22:27	richardlevan	Ok nice, thanks for the tips
22:27	andyf	and also if you can break it down to a minimal case that gives the same error.
22:31	ToxicFrog	richardlevan: for future reference, don't just say "I get a stack trace". Pastebin the whole stack trace somewhere and link it, and possibly mention what the exception that caused it is named.
22:32	ToxicFrog	richardlevan: in my case, both of those examples work fine, as long as I type the second one in from scratch.
22:32	ToxicFrog	richardlevan: if I copy-paste it, it fails because you use “hello” instead of "hello".
22:36	richardlevan	ToxicFrong: Thanks. I was about to put it in pastebin, but it turns out it was a silly mistake, looking further. I wrote (def c chan) instead of (def c (chan))
23:13	Hamled	Could someone explain why I get a "static field not found" exception when I do (map some.java.Class/staticFunc coll) but (map #(some.java.Class/staticFunc %) coll) works?
23:14	justin_smith	Hamled: methods are not first class
23:15	justin_smith	Hamled: Clojure could have decided to fake it, but instead it reflects the jvm's implementation
23:16	Hamled	ah, seems understandable. Is there some kind of java construct that would work in that scenario, or is the "static field not found" exception just the result of the implementation of map
23:16	Hamled	like, the exeption seems to imply to me that something perhaps other than a static method would be found if I tried to use that instead? I have no idea what that thing would be, though
23:17	justin_smith	Hamled: I think a java object that was callable / invokable might work as the first arg to map? not certain of that though
23:17	Hamled	ah
23:17	Hamled	a functor or something
23:17	justin_smith	methods are only usable within forms where they can be resolved to their object
23:18	justin_smith	not just a functor, an fn is an object that is callable / invocable for example
23:18	Hamled	oh
23:18	Hamled	I suppose that makes sense, where else would you put it
23:19	justin_smith	right, to refer to a thing in java, you need its object - technically we could have done somthing funky with static methods and their class
23:19	Hamled	I don't understand what you mean by "where they can be resolved to their object" -- wouldn't that not apply for a static method?
23:19	Hamled	oh okay
23:19	justin_smith	right, that's what I was getting at with "technically..."
23:19	Hamled	so the choice was not to special case static methods
23:19	justin_smith	that's my impression, yes
23:19	Hamled	cool, thanks :)
23:20	justin_smith	in general there is a priority in clojure for keeping designs simple
23:20	michaniskin	how would one debug why it takes a really long time to AOT compile certain namespaces?
23:20	justin_smith	michaniskin: are you creating something stateful like a server thread at the top level? that's a common issue
23:21	justin_smith	michaniskin: also, jstack will tell you exactly what each of your threads is doing, and you could run it during compilation
23:21	michaniskin	justin_smith: i'm pretty sure i'm not
23:21	justin_smith	OK
23:21	michaniskin	aha, that sounds like what i need, thanks!
23:21	justin_smith	try jstack and/or jvisualvm, yourkit, any of those can tell you where CPU is being burnt / what a thread is waiting on, etc.
23:22	michaniskin	yeah my cpu is not being utilized at all during the long wait
23:22	michaniskin	it seems like a TCP timeout or something crazy
23:23	justin_smith	michaniskin: creating a URL object? those are resolved when created (which is weird and leads to weird bugs)
23:23	michaniskin	justin_smith: whoa, i did not know that, but it makes sense
23:23	michaniskin	well sort of makes sense, maybe
23:23	justin_smith	it actually makes very little sense that just creating a java.net.URL would do a host lookup, but it does :)
23:25	michaniskin	yeah seems like something that could also be exploited somehow
23:38	andyf	michaniskin: If the wait is about 60 seconds, it could be a side effect of creating a future, or a call to pmap or clojure.java.shell/sh. See http://clojuredocs.org/clojure.core/future
23:42	michaniskin	i think it's repl related, this namespace takes a really long time to compile, and it's like 10 lines of code: https://gist.github.com/df72b821f4347ae9aab1
23:43	justin_smith	michaniskin: yeah, if that's it, I don't see why that would take so long to load, unless reply was doing something weird
23:43	justin_smith	nothing stateful is being created at the top level, clearly
23:45	justin_smith	woah, reply monkeypatches clojure.core
23:45	justin_smith	lol
23:45	justin_smith	https://github.com/trptcolin/reply/blob/master/src/clj/reply/hacks/printing.clj#L39
23:53	andyf	I think reply might depend upon something that creates a future at the top level, IIRC. We saw something similar with this with Leiningen, which depends on reply.
23:53	andyf	Let me see if I can find the issue
23:56	justin_smith	in that case you would want to call shutdown agents when compiling? that's terrible though