#clojure – 2014-06-28

2014-06-28

00:42	ivan	did any of the 54 people who retweeted https://twitter.com/mikeflynn_/status/482251458742472705/photo/1 check https://www.chrome.com/cubelab#tech
00:47	yedi	clojure is gone from there?
00:49	catern	was it shopped?
00:50	catern	yes
00:50	catern	it must have been
00:50	catern	Clojure isn't in all caps and the rest are
05:00	sveri	hi, anyone here using jig? the documentation says there needs to be a config.edn file in config folder, however putting a config folder into jig with a config.edn it seems like jig does not recognize this, how would I do this correctly (I dont want to put it into $HOME folder, if possible)
05:15	clgv	sveri: it's likely that you have to specify that config file somewhere, isn't it?
05:17	sveri	clgv: yea, I just found it, it has to be in the resources folder of jig
05:17	sveri	I think the documentation is a bit misleading here, however, looking at the code, things clear up, as most of the times :D
05:18	clgv	sveri: oh so it's rellay config at build time and after that it is "hard" to change without a rebuild
05:19	sveri	clgv: I think so
05:20	clgv	sveri: every time I take a look at jig's docs it seems not that "simple" as advertised
05:24	sveri	clgv: I just took two hours to get it running, but now it occured to me that I do have a dependency on jig that I might not need
05:25	sveri	clgv: I am still thinking about using it, especially the part that you cannot have a user.clj file in your sources is kind of disturbing to me
05:25	clgv	sveri: what's that about the user.clj?
05:26	sveri	clgv: https://github.com/juxt/jig#userclj
05:27	clgv	ah ok.
05:27	clgv	strange. why could jig just use any .jig. namespace?
05:27	sveri	clgv: that was my first thought too, I immediately opened an issue for this as I read it
05:28	sveri	any kind of application with some sort of user management will have a user.clj file on the classpath
05:29	clgv	sveri: another strang thing. it is not a proper library right? otherwise why would I have to clone jig itself?
05:29	clgv	sveri: no I think they only mean a toplevel user.clj
05:29	clgv	sveri: that's special stuff from leiningen which seems to be supported by tools.namespace as well
05:29	sveri	clgv: I am not sure about it, could be
05:29	magopian	is "Christophe Grand" around here?
05:30	sveri	clgv: I think the documentation is not explicit enough about it and leaves some doubt for me
05:30	clgv	magopian: sometimes as "cgrand" (or cgrande?) but apparently not right now
05:30	magopian	I live not far away from him I believe (something like 1.5hours of driving), and would love to meet someone that uses clojure in person ;)
05:30	magopian	clgv: ok thanks);
05:30	magopian	thanks ;)
05:36	clgv	sveri: did you clone that jig repo to use it or did you just add it as dependency to your project?
06:14	sveri	clgv: I cloned it, like the docs said
06:16	clgv	sveri: from different project it seems it could be used a normal lib. so they'd just make a leiningen template replacing the clone advice
06:18	sveri	clgv: I am not sure about that, did you find docs for this usecase? this would benice too I guee
06:18	sveri	*guess
06:18	clgv	sveri: no docs, but other project from the "juxt" user on github
06:53	sveri	clgv: you mean that modular project?
06:54	clgv	sceri: I meant that one https://github.com/juxt/juxt-accounting
06:58	clgv	sveri: ^^
07:07	sveri	clgv: I see, I was always wondering if you could add jig as a dependency
07:07	clgv	sveri: the only sane way if you ask me ;)
07:08	sveri	clgv: yea, otherwise every member of your team has to setup jig himself
07:38	leyluj	hello?
07:38	clojurebot	BUENOS DING DONG DIDDLY DIOS, fRaUline leyluj
07:39	leyluj	i just saw closure, i was aking mr bot where can i use closure?
07:40	ddellacosta	leyluj: Where can you use the language Clojure?
07:40	ddellacosta	leyluj: anywhere you got a JVM handy I guess. :-)
07:41	leyluj	so its a java kinda language ddellacosta?
07:41	leyluj	:)
07:41	ddellacosta	leyluj: well, Clojure runs on top of the JVM. But I wouldn't say it's very Java-like, no. It does provide good Java interop however.
07:42	ddellacosta	leyluj: there is also a JS-transpiled version, ClojureScript, which you may be aware of. I would check out the official site for a more thorough explanation though: http://clojure.org
07:43	leyluj	oh okay, im just starting out learning new stuff this 3 months and i saw clojure ... ddellacosta
07:43	leyluj	where can i apply it ? web apps? desktop apps? mobile apps?
07:43	ddellacosta	leyluj: welcome! I think you'll find it a fun language and the community is full of nice, helpful folks. If I do say so myself.
07:43	kungi_	leyluj: There is http://cljsfiddle.net/ where you can play around with clojure
07:43	ddellacosta	leyluj: well, I can tell you there is a lot of folks using it for web dev, as I am. There is also a fair bit of machine learning in Clojure.
07:44	ddellacosta	leyluj: You can write GUI apps with it as well, for example using SeeSaw: https://github.com/daveray/seesaw
07:45	ddellacosta	leyluj: I guess I would say it's pretty useful for many things, but falls a bit short on stuff like scripting--the JVM startup time makes that kind of prohibitive. However, there are even some projects which aim to mitigate that: https://github.com/technomancy/grenchman
07:45	leyluj	thank you ddellacosta... im loving the community already ..
07:45	ddellacosta	leyluj: :-)
07:46	leyluj	lemme go play with it and check on you laters cheers ... thanks once again
07:46	ddellacosta	leyluj: cheers, enjoy, and come back if you have questions.
07:47	ddellacosta	leyluj: this is a great place to start, btw: 4clojure.org
07:47	leyluj	aight then ddellacosta ... lemme hop on it
08:05	clgv	ddellacosta: though it is more the Clojure statup time thats a problem compared to the JVM startup time ;)
08:06	ddellacosta	clgv: right, correction! leyluj ^
08:06	clgv	hello?
08:06	clojurebot	BUENOS DING DONG DIDDLY DIOS, fRaUline clgv
08:07	clgv	ok he says fräulein all the time ,)
08:07	ddellacosta	clgv: you're lucky, clojurebot and I aren't on speaking terms
08:07	ddellacosta	,(println "don't make me cry clojurebot")
08:08	clojurebot	eval service is offline
08:08	clgv	yeah, read it some days ago ;)
08:09	clgv	,(println "don't cry.")
08:09	clojurebot	don't cry.\n
08:09	clgv	oops forgot the name^^
08:09	ddellacosta	hahaha
08:09	clgv	I liked the time when you could initiate a bot conversation like that ;)
08:36	ocharles	Hi folks, having to do packaging stuff for work and I need to download a jar manually from Clojars - is that possible?
08:37	ocharles	I'm not really a Clojure developer, I'm just helping out with some deployment stuff :)
08:37	ocharles	e.g., how would one get the jar for https://clojars.org/lein-cljsbuild/versions/1.0.3 ?
08:42	clgv	ocharles: https://clojars.org/repo/
08:43	ocharles	ah, perfect! thanks clgv
08:43	clgv	ocharles: but why not use leiningen or at least maven?
08:44	ocharles	clgv: somewhat a long story, but we do at the moment
08:44	ocharles	We use NixOS at work, which means that most of our builds are ran from clean environments - so every build requires downloading all dependencies
08:44	ocharles	I'm hoping to optimize that out, by moving the dependency resolution into the package manager itself
08:45	ocharles	It may end up being more pain than just waiting a little for lein to download dependencies, but I still want to explore it
08:56	nathan7	ocharles: Cool, never heard of anyone actually using NixOS in prod
08:56	ocharles	We're something of a rare breed :)
08:56	ocharles	But I don't know why, it makes an awful lot of sense
08:58	nathan7	Yeah, I dislike the Nix package language a bunch, but I love the concept
08:58	nooga	hi, I have seq fs of functions, I'd like to get sum of results: (reduce + (map (fn [f] (f 5)) fs)) is there a more idiomatic way?
08:58	p_l	nathan7: there's scheme-based toolkit on top of Nix
08:58	ocharles	nathan7: yea, the language itself is so-so
08:58	ocharles	nathan7: you know of guix too?
08:58	nathan7	ocharles: no, haven't heard of that
08:59	ocharles	That may be more up your street :)
08:59	nathan7	interesting
09:05	btcNeverSleeps	,(+ 2 3) ; testing the bot's syntax before asking a question
09:06	clojurebot	5
09:06	btcNeverSleeps	,(disj (into #{} (range 1 12)) 7 9) ; ok, works fine
09:06	clojurebot	#{1 4 6 3 2 ...}
09:07	btcNeverSleeps	,(let [v [7 9]] (disj (into #{} (range 1 12)) v)) ; <- doesn't do what I want
09:07	clojurebot	#{7 1 4 6 3 ...}
09:08	btcNeverSleeps	because v is passed to disj a single element and the set doesn't contain [7 9]. How can I solve that? (I don't know what to google for)
09:11	nathan7	apply
09:11	nathan7	(apply disj (set (range 1 12)) v)
09:11	nathan7	,(let [v [7 9]] (apply disj (set (range 1 12)) v))
09:11	clojurebot	#{1 4 6 3 2 ...}
09:12	btcNeverSleeps	nathan7: ah great, thanks
11:36	sandbags	Can anyone tell me how to get a ring server to log incoming requests to the console?
11:36	sandbags	i'm searching but can't seem to find any option for this
11:37	ddellacosta	sandbags: you could try this: https://github.com/pjlegato/ring.middleware.logger
11:38	sandbags	ddellacosta: thanks... i guess having a middleware do it makes sense, kind of
11:38	ddellacosta	sandbags: it's also pretty simple to just write a tiny little middleware layer to dump out requests using a logger
11:38	ddellacosta	yeah
11:38	ddellacosta	sandbags: what other way would you think may make sense?
11:38	sandbags	ddellacosta: well logging is kind of an essential function of a server and there's not a huge amount of magic to it
11:38	sandbags	i'm just surprised its not baked in
11:39	ddellacosta	sandbags: well, it's quite simple to do, which I suppose is part of the reason why it's not. I can't say I've ever found it lacking as I've done web dev in Clojure
11:40	sandbags	it's not a big deal, i was just surprised is all
11:40	ddellacosta	sandbags: I guess you could probably also set up logging defaults for Jetty too
11:52	halogenandtoast	Is the (into []) here https://gist.github.com/halogenandtoast/58cf169f271d49f69005#file-progress-clj-L31 necessary, without it line 54 breaks but it seems redundant to me.
11:55	Frozenlock	halogenandtoast: You could maybe use 'mapv' if you don't want 'into []'
11:57	halogenandtoast	Frozenlock: Sure enough that seems to work, now I need to understand why. Reading up.
11:58	halogenandtoast	mapv is also not lazy it seems.
11:58	halogenandtoast	Which is good because I don’t want a lazy sequence.
11:59	Frozenlock	mapv is a shorthand for (into [] (map ...
11:59	ticking_	halogenandtoast: If you don't want lazyness use reducers.
11:59	ticking_	they will give you a significant performance boost
12:00	halogenandtoast	ticking_: I’ll give them a try, but the performance boost is negligable the map should run between 2-4 times and there is io between each call.
12:00	ticking_	Frozenlock: only when applied to more than one collection. In the simple case it even uses transients so it should be rather fast.
12:01	ticking_	https://github.com/clojure/clojure/blob/028af0e0b271aa558ea44780e5d951f4932c7842/src/clj/clojure/core.clj#L6344
12:01	ticking_	halogenandtoast: mapv is your friend then
12:01	Frozenlock	ticking true
12:01	halogenandtoast	does the v stand for vector in this case?
12:01	ticking_	yes
12:02	halogenandtoast	Cool
12:03	halogenandtoast	Off to the smorgasburg, thanks ticking_ and Frozenlock
12:07	nathan7	ticking_: how's life?
14:34	travisr	does anyone have insight as to why re-match, without wildcards doesn't automatically substring the string under test?
14:35	travisr	ala grep...
14:36	ticking_	travisr: because re-find has that behaviour?
14:36	travisr	e.g., if I have a regex expression #"cat", this will not match: "somecathere"
14:36	travisr	the question was why.
14:36	travisr	@ticking_ ^
14:37	ticking_	that is why
14:37	ticking_	travisr: clojure regexes are just thin wrappers around java regexes
14:38	ticking_	travisr: and java has match and find methods to apply a regex to a string, where match tries an exact match and find tries to find a substring
14:38	travisr	thanks... I will look into that...
14:38	ticking_	http://docs.oracle.com/javase/7/docs/api/java/util/regex/Matcher.html
14:39	ticking_	So if you want grep like behaviour use re-find, otherwise use re-matches
14:39	travisr	got it... thanks
14:40	travisr	thanks... that is perfect.
14:40	travisr	i just tried it and it works exactly as you've said.
14:40	travisr	thanks again
14:41	ticking_	youre welcome ^^
14:41	metellus	(inc ticking_)
14:41	lazybot	⇒ 1
15:02	Frozenlock	(dec so)
15:02	lazybot	⇒ -30
15:51	Shayanjm	if I have an atom which I'm using to store various pieces of data, is it 'bad clojure' to create functions that take 0 parameters and update ONLY that atom with relevant data?
15:51	Shayanjm	or should I be creating more general functions which take the atom as a parameter?
15:53	jeremyheiler	Shayanjm: i'd create the general functions
15:54	jeremyheiler	also consider how you'll test the functions
15:55	Shayanjm	Sure, that's fair
15:55	Shayanjm	thanks
15:56	jeremyheiler	if the requirements change and suddenly you'll need two atoms, then you'll probably be grateful for having the general functions.
15:57	bbloom	if you can help it, i'd avoid taking atoms at all
15:57	benkay	if i'm going to be serving a buttload of images with a ring server, it'd be a bad idea to pull the images off the disk on each request, right? is there an idiomatic approach to storing binary data in memory and then serving that as though it were a static file?
15:57	bbloom	make the functions totally pure
15:57	bbloom	and use them with swap!
16:01	martinklepsch	count will exhaust a lazy seq right?
16:01	bbloom	(doc count)
16:01	clojurebot	"([coll]); Returns the number of items in the collection. (count nil) returns 0. Also works on strings, arrays, and Java Collections and Maps"
16:01	bbloom	oh, i thought it documetned that
16:01	bbloom	martinklepsch: but yeah, it will
16:01	bbloom	but note that "lists" are counted in constant time
16:01	bbloom	(doc counted?)
16:01	clojurebot	"([coll]); Returns true if coll implements count in constant time"
16:01	bbloom	,(counted? (list 1 2 3))
16:01	clojurebot	true
16:02	bbloom	,(counted? (lazy-seq (list 1 2 3)))
16:02	clojurebot	false
16:07	benkay	caching? ring? anyone?
16:09	Jaood	benkay: why don't you use nginx for that?
16:10	benkay	naively, perhaps, i'd prefer to keep as much of the logic in the app as possible. i'd hope that (using jetty) would be well enough written to serve static assets out of memory relatively performantly.
16:11	benkay	that ring, using jetty...
16:12	benkay	mind you, i know next to nothing about how jetty works under the hood. i'm blessed with well-written wrappers.
16:13	benkay	am i completely off my rocker, Jaood ?
16:13	seangrov`	Anyone know if fressian can compress native clojure data structures with structural sharing?
16:13	seangrov`	(pr-str ..)-ing the data is madness, it balloons horribly
16:14	bbloom	seangrov`: fressian is primarily about streaming, it only caches some number of recently printed values
16:14	bbloom	i think it's like 90-something
16:14	bbloom	but i too have wanted full interning
16:15	bbloom	also unfortuantely, internal data types (like red/black nodes) aren't exposed in any meaningful way with equality or hashing or anything like that
16:15	Jaood	benkay: if is a "buttload" of you images as you say why do you want to keep them in memory? anyway, nginx is highly optimized for serving static assets
16:15	bbloom	so there's no good way w/ standard clojure structures to recover internal sharing
16:17	benkay	Jaood: i may be engaging in premature maloptimization ;)
16:17	seangrov`	bbloom: Yeah, I was worried about that
16:18	bbloom	seangrov`: unfortunately, your options are pretty limited for general purpose solutions... you'll be best off just writing a custom serialization transform
16:19	benkay	another constraint i'm dealing with is that the request is going to hit /images/thinger_x_y.png which will need to serve one of a set of images - i suppose that ring could return a redirect to the path from which nginx would serve the specific image in question.
16:22	seangrov`	bbloom: So many cool features that could be realistically enabled if the structural sharing wasn't opaque
16:22	seangrov`	Maybe I'll give it a go in a few weeks
16:23	bbloom	seangrov`: yes. big time. i've really wanted that
16:23	bbloom	seangrov`: as is, you'd basically have no choice but to re-implement all the main data structures
16:23	bbloom	also, there's a trade off between "hash-cons" style creation and deferred recovery of sharing
16:24	bbloom	in the former, you achieve perfect sharing, at the cost of reduced construction rate
16:24	bbloom	in the later, you pay a pause cost in a GC-style transform that recovers sharing
16:25	seangrov`	Aren't the cljs data structures using hash-cons style?
16:25	bbloom	seangrov`: no
16:25	bbloom	to do hash-cons-ing you need a lookup table
16:25	bbloom	which would prevent GC in js (no weak refs)
16:29	seangrov`	bbloom: How about jvm-clj then?
16:30	bbloom	seangrov`: nope. it's the wrong trade off for functional programs
16:30	bbloom	you want high construction rates
16:30	seangrov`	Ah, makes sense
16:30	bbloom	it's the classic space/time tradeoff analogous to ref counting & tracing GC
16:40	sveri	ocharles: you could take it from .m2 folder after having declared a dependency on it
16:43	sveri	ocharles: you could also clone the commit of the specific release and build a jar yourself with lein jar
16:44	arohner	is there any trick to making the datomic maven repo work? I can download datomic releases over http just fine, but lein seems to be having trouble
16:44	arohner	and I've used lein credentials and :env/foo without trouble before
16:50	arohner	sigh, password vs. passphrase
17:01	benkay	arohner: i usually download datomic, and then bin/maven-install - is that what you're doing?
17:01	arohner	no, I added "my.datomic.com/repo" to lein repos
17:01	benkay	i had no idea that was even a thing
17:01	arohner	instructions are at https://my.datomic.com/account
17:03	benkay	sigh another password reset...
17:06	benkay	makes me wonder, if the datomic team expects one to have a gpg toolchain set up already why not just ask for a clearsigned token?
17:16	gastove	Anybody in here game for a Reflection question? I'm trying to figure out how to access static methods on a class stored in a var.
17:26	Shayanjm	if I only want to get the text content from an enlive select - how might I go about doing that? I'm having issues with stuff like links inside the content body
17:28	gastove	reflect
17:28	gastove	Whoops, wrong window, sorry.
17:28	Shayanjm	https://gist.github.com/shayanjm/e5ebf21a4d57c84a4718
17:31	arohner	clojurebot: ~anyone
17:31	clojurebot	Cool story bro.
17:31	arohner	~anyone
17:31	clojurebot	Just a heads up, you're more likely to get some help if you ask the question you really want the answer to, instead of "does anyone ..."
17:32	arohner	gastove: https://github.com/arohner/clj-wallhack/blob/master/src/wall/hack.clj has some examples of using reflection
17:33	gastove	Ha. Thanks for the pointer, arohner.
17:33	Bronsa	si`
17:34	gastove	arohner: and thanks for the github link!
17:34	arohner	np
17:35	gastove	Trying again, here's my question: I have a static class stored in a var. I need to call a static method from that class. I cannot figure out how the hell to do it.
17:36	arohner	gastove: look at wall.hack/method "obj - nil for static methods"
17:39	gastove	arohner: Cool, I'll poke at that.
17:45	Shayanjm	if I have a map {:thing "something" :content "realcontent" :secondthing {:thirdthing "another thing" :content "something again"}} (for example)
17:46	Shayanjm	how do I identify and string together :content all the way into the nested map?
17:46	Shayanjm	(assuming the nested map is of unidentified structure and could have more than just 2 layers)
17:52	kristof	Shayanjm: you could flatten it first
17:53	kristof	And then... bazam! Just pretend like it's a simple hash map.
18:20	TravisD	emacs
18:20	TravisD	oops.
18:28	kristof	Not-ur-term-m8
18:28	kristof	(decf TravisD)
18:28	kristof	(dec TravisD)
18:28	lazybot	⇒ 2
18:28	kristof	:)
18:28	TravisD	hehe, ouchies
18:41	noncom\|3	please excuse me, if i am rude, but have you ever wanted to punch in the face a person who gives examples of usage of his lib, loaded with (use) or (require :refer-all) ns declarations?
18:46	kristof	Why would that be bad?
18:52	noncom\|3	because it has lots of functions from, say 5-10 different namespaces. and in a real app, i cannot use (use) or (require :refel-all). and then i have to manually pick each function from its namespace. but in order to know which one of the tiny functions comes from where, i have look it up in the source
18:52	noncom\|3	does that make sense?
18:52	TravisD	kristof: I guess if there are multiple modules in the library, it can be difficult to figure out where things are defined
18:52	noncom\|3	or am i missing something?
18:53	kristof	that does make sense
18:53	kristof	but that can't be too hard
18:53	noncom\|3	personally i would consider (use) or (require :refel-all) an antipattern
18:54	benkay	grep can help with those situations, noncom\|3 ;)
18:54	benkay	jokes aside, i'm totally with you.
18:54	TravisD	I don't understand the term antipattern. In my mind, that means the lack of a pattern, and not a pattern which shouldn't be
18:54	benkay	wouldn't that be an unpattern?
18:54	noncom\|3	that is that too bad since if i cannot remember which comes from where, there are too many of them.. and a tiny error would cause repl to be unable to eval the stuff and exit. since i work with opengl that causes the context to be lost and i have to re-launch all the stuff anew
18:54	benkay	noise?
18:55	benkay	noncom\|3: yeah, you defo want to avoid use in your own code
18:56	benkay	also i try to save my limited supply of punches-through-the-internet for the ecmascript implementors.
18:56	noncom\|3	haha :D
18:56	benkay	and everyone who ever wrote a django app that survived to become legacy code (including myself)
18:57	noncom\|3	oh yes, in that land, there is even more of that kind of badness ...
18:58	benkay	noncom\|3: in my experience reading the source is the best way to get to know clojure libs. documentation is sparse, and reading source has done more for me as a developer than all of the curl2sudo(tm) "easy" things that lib documentors and authors have done in other languages.
18:58	benkay	but your tastes may vary.
18:58	benkay	and mileage.
18:58	noncom\|3	i agree with you..
18:59	noncom\|3	but now we are long past deadline and studying these wonderful pieces of code inside does not make me any happier..
18:59	benkay	hahahaha
18:59	noncom\|3	:)
18:59	benkay	carry on, soldier
18:59	benkay	me, i'm going to have another bloody mary.
19:00	noncom\|3	thanks :)
19:52	noonian	noncom\|3: slamhound could help in those situations, just get a repl up, remove the use form, and run slamhound; it will fix up the ns form with proper requires
19:55	noncom\|3	noonian: thanks for the advice, gonna check it out!
21:27	echo-area	I think I have found a good use of dynamic vars: I need extra information in a watch function, but don't want to modify the watched reference object. Hence I use a dynamic var for carrying this information.
21:28	echo-area	Using of dynamic var in this scenario seems natural and proper to me. What do you think?
21:31	technomancy	can't use metadata?
21:33	echo-area	That information also depends on the context
22:53	gastove	Hi all. I'm trying to access a static method on a class using reflection, using a method from clojure.contrib (http://clojuredocs.org/clojure_contrib/clojure.contrib.reflect/call-method). I'm getting a pretty nonsensical error (array element type mismatch), and am generally pretty bewildered. Would anybody be able to offer some guidance?
22:55	gastove	(The specific problem I need to solve is: I need to call a static method on a java class stored in a variable.)
23:08	gws	gastove: are you able to paste a snippet of what you're doing?
23:09	gastove	Sure -- give me a second to put together something comprehensible.
23:09	gastove	Part of the problem I'm trying to figure out is: every way I've seen to use reflection to access a static member of a class assumes you'll pass the name of the method as a string. But, the static method I'm trying to access dispatches on both type and arity -- so how do I specify which one I want?
23:19	gastove	gws: Here we are. https://gist.github.com/Gastove/b083083f22d7f198d964
23:43	gastove	Or, if you like: http://stackoverflow.com/questions/24472968/invoke-a-static-method-on-a-java-class-stored-in-a-var