#clojure – 2012-11-11

2012-11-11

00:23	akr	Hi! How can I add extra jars in java classpath?
00:23	akr	I am using leiningen
00:24	akr	A SO thread mentioned that if I should create a lib/ directory and put my jars there they will be automatically available
00:28	akhudek	akr: did you try that? I suspect it's correct, though I was under the impression that the lib directory was cleared out when you do a lein clean. Perhaps that's changed with lein2 though.
00:29	akhudek	I usually just install jars into my local maven repository.
00:29	akhudek	with this http://maven.apache.org/guides/mini/guide-3rd-party-jars-local.html
00:30	akr	I will try to put them in local m2 repo
03:33	Inst	does anyone use haskell here?
03:33	Inst	how does clojure compare to haskell?
05:07	doomlord	does clojure have a predicate to tell if 2 variables are of the same type; and possibly by extention to tell if a collection is homogeneous
05:10	dspp	,(instance? clojure.lang.Sequential [])
05:10	clojurebot	true
05:10	wingy	i dont think that was what he wanted
05:11	wingy	he wanna look if "a" and "b" is of the same type
05:15	dspp	yeah, i know
05:15	dspp	,(instance? clojure.lang.Sequential [] [] [])
05:15	clojurebot	true
05:15	dspp	,(instance? clojure.lang.Sequential [] [] \t)
05:15	clojurebot	true
05:15	dspp	(type [])
05:15	dspp	,(type [])
05:15	clojurebot	clojure.lang.PersistentVector
05:16	dspp	,(every? #(instance? clojure.lang.PersistentVector %) '([] [] [] [] \c))
05:16	clojurebot	false
05:16	dspp	,(every? #(instance? clojure.lang.PersistentVector %) '([] [] [] [] []))
05:16	clojurebot	true
05:16	dspp	tadaaa
05:37	pyr	hi
05:37	pyr	Is the process for submitting to sub-projects the same than for clojure ? (i.e: JIRA + contributor agreement ?)
05:38	pyr	I have a PR for tools.cli
05:55	doomlord	,(typeof "foo")
05:55	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: typeof in this context, compiling:(NO_SOURCE_PATH:0)>
05:55	doomlord	ok instance and type do it
06:19	sunkencityryleh	is there some way I can filter for not nil without writing (filter #(not (nil? %)) arr)
06:20	shachaf	What don't you like about writing that?
06:20	shachaf	(comp not nil?) == #(not (nil? %))
06:21	edlothiol	(remove nil? arr)
06:21	edlothiol	(filter (complement nil?) arr)
06:21	sunkencityryleh	ah, that's better
06:21	shachaf	That works.
06:21	jakubH	nil is interpreted as false so also this would work
06:21	jakubH	,(filter identity [1 nil 3])
06:21	clojurebot	(1 3)
06:22	jakubH	though there are certainly nicer ways
06:22	jakubH	remove is nicer
06:22	sunkencityryleh	remove makes it as simple as it should be
06:23	sunkencityryleh	thanks
06:30	sunkencityryleh	I want to find the smallest thing in a list with a function. I can do this with apply (apply min-key #(Math/abs %) [-3 1 4]), but how can I transform the code so that it doesn't bork on an empty list? I could use if of course, but is there some other way?
06:33	raek	sunkencityryleh: what is the smallest value of the empty list? :)
06:33	raek	sunkencityryleh: one way could be to add a smallest possible value to the collection
06:35	raek	another way could be to make a check for the empty list and return a special value
06:35	sunkencityryleh	raek: yep, i'm checking for empty list now, because I have to handle it specially anyway I just realized
06:36	raek	(defn smallest-number [coll] (if-not (seq coll) :no-such-value (apply min-key #(Math/abs %) coll)))
06:36	raek	(defn smallest-number [coll] (apply min-key #(Math/abs %) (cons 0 coll)))
06:37	sunkencityryleh	yep, Im going with the if-not thing
06:37	raek	"(if (empty? coll) ..." looks slightly better...
06:37	sunkencityryleh	writing a textile -> hiccup tool so I need to find next closest token
06:37	clojurebot	hiccup is http://tinyurl.com/426og7n
07:05	Netfeed	hi, i have these two macros: http://pastebin.com/avf6zz4W and i have a "problem", i'd like to define a function (defn select-first [sql & binds] (first (select sql binds))), but it doesn't work, this works though (defmacro select-first [sql & binds] `(first (select ~sql ~@binds))) but it feels overkill, how can i get the first case to work?
07:12	hcumberdale	cemerick not here ;(
07:14	joegallo	Netfeed: Since you've defined it as sql & binds, you'd want to (apply select sql binds) so that the binds would be carried through correctly.
07:14	joegallo	However.
07:14	joegallo	You can't do that with a macro since apply works on functions, no macros.
07:15	Netfeed	oh, so i have to stick with the latter?
07:16	joegallo	It works, it's not wrong to do it that way. I'd recommend you carry on with writing useful software and not worry about it. ;)
07:16	Netfeed	heh, ok, thanks
07:16	joegallo	That said, it's a fine demonstration of the infectious nature of macros, so maybe make a note of that.
07:18	Netfeed	but it's so handy :)
07:19	hcumberdale	I can't catch slingshot exceptions, don't know why
07:19	hcumberdale	tried a lot,... (try+ (catch Exception e _ ...
07:19	hcumberdale	(try (catch Exception e _
07:19	hcumberdale	...
07:21	hcumberdale	https://www.refheap.com/paste/6538
07:21	hcumberdale	any ideas?
07:28	joegallo	i think they're throwables, not exceptions?
07:32	hcumberdale	joegallo how to catch them?
07:32	joegallo	(catch Throwable t ...)
07:33	joegallo	That said, that would be hugely overkill.
07:33	hcumberdale	Lets try
07:34	joegallo	Maybe peek around cemerick's library and see what he does? Catching Throwable is almost certainly not what he intends, and it's certainly not what Steve G intended with slingshot.
07:34	joegallo	You're supposed to catch it based on the contents of the thrown map, per the documentation on slingshot.
07:34	hcumberdale	Yes joegallo! But friend does not behave as expected
07:34	hcumberdale	When I browse a route like /user and I am not logged in the exception/throwable is fired
07:35	hcumberdale	But it does not get caught
07:35	hcumberdale	no ":unauthorized-handler" is called
07:36	hcumberdale	it seems it does not care if there is such a handler or not
07:36	hcumberdale	(catch Throwable e (print "NOT AUTH!"))) << also throws the exception
07:37	hcumberdale	It does not get caught
07:38	joegallo	I'm guessing your catch expression isn't in the right location, then.
07:48	ro_st	is there a way to get a seq of all a fn's args from inside the fn body without using :as in the arg vector?
08:17	ambrosebs	,(instance? clojure.lang.Sequential [] [] [])
08:17	clojurebot	true
08:17	ambrosebs	wtf?
08:18	ambrosebs	Why doesn't this throw an arity error?
08:19	ambrosebs	There's probably some inlining deep in the Compiler for instanceof optimisation.
08:20	ambrosebs	Well, there is, but not sure if that's the issue.
08:21	ambrosebs	Seems like a known issue http://stackoverflow.com/questions/13176400/clojure-instance-single-argument
08:24	joegallo	appears to me that instance? is defined in terms of the relatively primitive fn at line 42 of core.clj, rather than the more featureful fn defined at line 3989
08:24	joegallo	so yeah, no arity checking
08:24	joegallo	at least, that's my quick read of it
08:28	hcumberdale	mhh
08:29	hcumberdale	(defroutes ring-app
08:29	hcumberdale	;; requires user role
08:29	hcumberdale	(compojure/context "/user" request
08:29	hcumberdale	(try (friend/wrap-authorize user-routes #{::user})
08:29	hcumberdale	(catch Throwable e (print "NOT AUTH!"))))
08:29	hcumberdale	The exception should be thrown by wrap-authorize?
08:29	hcumberdale	right
08:30	hcumberdale	?!
08:30	hcumberdale	https://github.com/cemerick/friend/blob/master/src/cemerick/friend.clj#L302
08:30	joegallo	or does wrap authorize return a fn that will later do the checking?
08:30	joegallo	that appears to be what it does, based on what you linked me to
08:30	joegallo	sooo... yeah, wrong spot.
08:31	hcumberdale	why wrong spot?
08:31	hcumberdale	it calls throw-unauthorized
08:31	joegallo	no it doesn't.
08:31	joegallo	it returns a fn that will do so later.
08:31	joegallo	well outside of the context of your try/catch.
08:31	hcumberdale	where exactly does that happen
08:31	ambrosebs	joegallo: I think the stackoverflow answer has the right idea. The compiler emits an InstanceOfExpr without checking the number of arguments to instance?
08:31	joegallo	line 299
08:32	joegallo	a defn that return a fn
08:32	hcumberdale	yeah, i've seen that. But where is it evaluated?
08:32	joegallo	hcumberdale: i'm sure i don't know, somewhere else in the bowels or your app
08:32	joegallo	s/or/of/
08:33	joegallo	ambrosebs: sure, sounds reasonable.
08:34	hcumberdale	joegallo, but then it seems like a bug in friend
08:34	joegallo	no, that's how ring works
08:35	hcumberdale	but why is default-unauthorized-handler not called
08:35	hcumberdale	since it is build to catch unauthorized requests
08:36	hcumberdale	https://github.com/cemerick/friend/blob/master/src/cemerick/friend.clj#L196
08:36	hcumberdale	Why must a user be auth'ed to call the unauthorized-handler ?
08:37	hcumberdale	Also redirect-unauthorized does not work
08:37	hcumberdale	The exception bubbles up, no handling by friend as it is expected
08:37	flying_rhino	hello guys
08:37	hcumberdale	hi flying_rhino ;)
08:38	joegallo	hcumberdale: i think you need to also be calling authenticate somewhere -- which i'm not sure you are. you keep pointing to parts of it, but it doesn't appear that it's ever called as a result of wrap-authorize (i think).
08:39	joegallo	it seems like your pretty lost here, and i've never read or worked with friend before, so my suggestion is that you look for some existing code elsewhere that uses friend that you can use as an example
08:39	hcumberdale	I'll refheap the whole program, sek
08:40	joegallo	or that you wait for cemerick to come on and see if he can give you a hand
08:40	hcumberdale	https://www.refheap.com/paste/6540
08:40	hcumberdale	joegallo, i searched for existing applications. Can't find any
08:41	hcumberdale	that work with compojure as in the examples and with wrap-auth...
08:41	joegallo	i think wrap-authorize is only for when you've already used authenticate as earlier middleware
08:41	joegallo	which you haven't
08:41	hcumberdale	https://www.refheap.com/paste/6540#L-42
08:41	joegallo	but again, this is my very first read of this library, which i've never used, so yeah...
08:41	hcumberdale	I've
08:42	joegallo	okay, missed that. anyway, best of luck, but i've got nothing.
08:42	hcumberdale	./ping cemerick << yesterday he said bbl. Haven't seen him since then
08:44	flying_rhino	anyone ever tried to implement immutable entity systems in clojure?
08:44	hcumberdale	flying_rhino like datomic ?
08:47	flying_rhino	I don't know what is datomic, but Component Entity System is, in short, extremely data driven method of developing games. You have bunch of structs (components) that you manipulate using Systems. It looks a little like relational database and separates data from code.
08:48	flying_rhino	It is usually done in mutable languages
08:48	flying_rhino	*imperative languages
08:49	flying_rhino	this link explains the whole thing http://t-machine.org/index.php/2007/09/03/entity-systems-are-the-future-of-mmog-development-part-1/
08:49	hcumberdale	Is there such an existing sytem for LISP?
08:50	flying_rhino	it is popular for mmorpgs, but can be used for other games as well.
08:50	flying_rhino	dunno
08:50	flying_rhino	I could implement one but I am asking around first.
08:51	flying_rhino	on the face of it it does look like immutability could help a lot but I am far from experienced functional programmer.
08:53	hcumberdale	joegallo, got it working
08:53	hcumberdale	;)
08:53	hcumberdale	what is a mmorpg for example?ß
08:53	hcumberdale	wow?
08:53	joegallo	hcumberdale: what was it?
08:54	joegallo	also, nice work!
08:54	hcumberdale	joegallo, i am not sure ;(
08:54	joegallo	argh
08:54	hcumberdale	done lein2 clean and lein2 run
08:54	hcumberdale	and the code I posted runs 1:1
08:54	hcumberdale	crazy ;(
08:55	joegallo	i feel totally unsatisfied :)
08:57	hcumberdale	had the same problems before with another lein2 project
08:58	hcumberdale	but it was not the auth that lagged
08:58	joegallo	oh, maybe you're getting killed by aot?
08:58	joegallo	and that classes you're aoting are stale and out of date wrt the clj files you're editing?
08:59	hcumberdale	http://stackoverflow.com/questions/8291910/noclassdeffounderror-with-clojure-tools-logging
08:59	hcumberdale	Had the same issue, lein clean, and then lein deps, and then lein compile fixed it
09:00	hcumberdale	This whole AOT thing sucks
09:00	wink	classic: writing (> 0 x) instead of (> x 0) and then reading up on the clojure type system for 30min, questioning sanity
09:01	callen	hcumberdale: remember, you could be wrangling with cabal.
09:01	wingy	datomic supports couchbase!
09:01	callen	wingy: I won't use it until it supports kyoto cabinet.
09:02	wingy	sounds exotic
09:02	callen	thats_the_joke.jpg
09:03	wingy	i just know one thing
09:03	wingy	no aws!
09:03	hcumberdale	Why wingy?
09:03	hcumberdale	Because of the big aws fallout ;)
09:04	callen	you say that as if there was only one.
09:04	hcumberdale	I've seen only one callen
09:04	callen	AWS US-East has gone down many times.
09:04	wingy	because they do everything
09:04	hcumberdale	my blog was down, hosted on heroku
09:04	wingy	but nothing innovative
09:04	callen	The real trick is to just let US-East continue to vanguard the scalability issues
09:04	callen	and just use US-West or something other AZ
09:05	hcumberdale	But it's not possible to choose with heroku
09:05	hcumberdale	+ mongohq, they are also using aws
09:05	callen	hcumberdale: your choice of master for your sharecropping isn't my problem.
09:05	ferd	Is there something similar to "tree-seq" but parallelizable? (therefore, non-lazy)?
09:05	ferd	...that is, I want it to call my "children" function in parallel to keep expanding the tree concurrently
09:05	callen	I'm just making it explicit that it isn't the entirety of AWS that goes down, it's usually just US-East which is a detail that can be exploited.
09:06	hcumberdale	callen, thx for the info
09:06	hcumberdale	US-West = same price as US-East ?
09:07	callen	hcumberdale: mostly yes, if you mean Oregon
09:08	callen	Northern California is slightly more expensive.
09:08	hcumberdale	Have you production applications running on aws?
09:08	callen	If you're using AWS, caring about expense is a bit like caring about getting wet while swimming across the channel.
09:08	hcumberdale	;)
09:08	callen	hcumberdale: I've built more than one production system on AWS, although I try to use it as little as possible these days.
09:09	hcumberdale	callen: what's the best alternative?
09:09	callen	that's like asking what's the best car.
09:09	callen	Depends entirely on what you're doing. There are still some use-cases that AWS is superior at.
09:10	callen	for my part, I favor a mix of VPSs and renting dedicated hardware.
09:11	hcumberdale	yes callen, I think that's a good idea and you might reach less outtakes
09:11	hcumberdale	But you have to worry about to OS/Updates/Maintenance
09:11	hcumberdale	Evil bad hackers ;)
09:11	callen	what you just said makes no sense.
09:11	callen	nothing about that changes when you're using AWS.
09:12	callen	you do understand that EC2 is just a VPS, right?
09:12	callen	evil bad hackers. snorts
09:12	hcumberdale	But when you use heroku and services over EC2, they care for you
09:13	cmn	but that's something different; you were asking about AWS, not heroku
09:13	cmn	IIRC engineyard provide a similar service and are based on rackspace
09:13	hcumberdale	Heroku is based on AWS so server failure effects both
09:14	cmn	yes
09:14	cmn	but that wasn't the conversation
09:14	callen	that also means that if AWS goes down, you're fucked anyway, heroku or no.
09:14	hcumberdale	;) yes.
09:14	hcumberdale	http://www.engineyard.com/ << no clojure
09:14	callen	it was with extreme pleasure that I was one of the few startup people I knew that didn't experience any downtime during the AWS blip.
09:15	cmn	heroku are starting to roll out some servers on the west coast
09:15	callen	hcumberdale: ...and? Nobody's trying to sell you on anything in particular.
09:15	hcumberdale	own servers cmn?
09:15	cmn	no
09:15	callen	heroku isn't going to stop using EC2.
09:15	callen	Their devops infrastructure is heavily tied into it.
09:15	callen	they're stuck with Amazon.
09:16	callen	incidentally this is why I refused to use AMIs when I used AWS more heavily. It meant that switching away was just a matter of repointing scripts, instead of having to rebuild the automation stack.
09:18	hcumberdale	mhh..
09:18	hcumberdale	Is there any real competitor to EC2/AWS?
09:18	callen	bits and pieces.
09:19	callen	Rackspace, Azure in the large. In the small, Linode et al.
09:19	cmn	but it all depends on what you need
09:19	callen	There are plenty of companies that offer one-off things like MongoHQ that are analogous to AWS RDS.
09:19	hcumberdale	Rackspace cloud is really new, isn't it?
09:20	cmn	and what if it isn't?
09:20	cmn	AWS isn't new
09:20	callen	hcumberdale: do you have something in particular you are aiming for?
09:22	hcumberdale	callen, just want to hear about your experience with the solutions/providers. I've discovered the problems with heroku/mongohq and AWS a few weeks ago
09:22	callen	your needs seem pretty low level. You could truck along with "whatever" for hosting a blog.
09:22	Licenser	hcumberdale joyent
09:22	wink	I've been bitten by AWS performance once, badly. Still a bit cautious to see the positive aspecs :(
09:25	hcumberdale	Yes the requierements for a blog are really low-level. I'm interested in big applications running on EC2
09:25	hcumberdale	Seems to most hosting companies tend to sell vservers now as 'cloud'
09:25	Licenser	should take a look http://joyent.com/ :) they are pretty awesome
09:25	callen	I've built big clusters, but I need something specific to really be able to tell you what's up and down.
09:26	callen	I'm not going to exposit aimlessly in IRC about what I do and do not like about AWS.
09:28	hcumberdale	Never heard about joyent, website looks interesting. Licenser, have you any clojure applications running there?
09:29	Licenser	hcumberdale nope but I am using the underlying hypervisor for my stuff - where I also run java applications (just no clojure)
09:29	Licenser	but java works great and so should clojure then
09:35	jonasen	I'm trying to release a new version of Kibit but I seem to have messed up. Could someone try the new [lein-kibit "0.0.5"] and see if it works?
09:38	wink	jonasen: $ lein kibit Check :dependencies and :repositories for typos. It's possible the specified jar is not in any repository. If so, see "Free-floating Jars" under http://j.mp/repeatability Could not resolve dependencies
09:39	wink	$ cat ~/.lein/profiles.clj
09:39	wink	{:user {:plugins [[lein-kibit "0.0.5"]]}}
09:55	pyr	wouldn't it be cool to have a ns construct that would let you pull in a standard config (require's, use's, import's etc)
10:02	joegallo	pyr: http://code.google.com/p/clj-nstools/
10:03	pyr	ah, nice
10:04	jonasen	wink: I think I got it working now, could you try [lein-kibit "0.0.7"] instead?
10:05	wink	jonasen: yes, and the results hurt my feelings! :)
10:05	wink	good reminder to use it on this project
10:05	jonasen	wink: Thanks alot!
10:07	pyr	joegallo: for that type of functionality I would be hesitant to bring in a new dep
10:08	joegallo	then i guess you don't get that functionality. :(
10:08	pyr	yup
10:12	_ulises	,(doc list*)
10:12	clojurebot	"([args] [a args] [a b args] [a b c args] [a b c d & ...]); Creates a new list containing the items prepended to the rest, the last of which will be treated as a sequence."
10:12	_ulises	,(doc list)
10:12	clojurebot	"([& items]); Creates a new list containing the items."
10:13	_ulises	,(list? (list* (set '(a b c))))
10:13	clojurebot	false
10:13	_ulises	hum
10:13	_ulises	,(list? (list (set '(a b c))))
10:13	clojurebot	true
10:13	_ulises	,(list (set '(a b c)))
10:13	clojurebot	(#{a c b})
10:13	_ulises	(set '(a b c))
10:14	_ulises	,(set '(a b c))
10:14	clojurebot	#{a c b}
10:14	_ulises	,(list* (set '(a b c)))
10:14	clojurebot	(a c b)
10:14	_ulises	sorry for spam
10:14	raek	the name for list* is a bit misleading. it produces an ISeq, not an IPersistentList
10:15	_ulises	oh!
10:15	_ulises	raek: thanks!
10:15	raek	(list* x y z some-seq) is like (cons x (cons y (cons z some-seq)))
11:31	si14	hi, guys. Is there any example of Java usage from Leiningen repl?
11:32	Licenser	si14 I think it's the same as in all clojure
11:32	Licenser	a simple example would be (System/exit 0)
11:33	si14	Licenser: I don't understand the thing with Classpath and such.
11:33	Licenser	ah okay, that kind of stuff, to be honest - I've no clue :(
11:34	ChongLi	si14: what don't you get about classpath?
11:34	si14	ok, I've added project.clj; added java-source-paths to it; I have foobar.java in that path and when I do something like (import Foobar) I get "no such file"
11:35	ChongLi	I think you need to compile your java first
11:35	ChongLi	into a jar
11:40	_ulises	si14: not just that, you have to import packagename.othername.ClassName
11:42	si14	oh, I've managed to make it work! :) updated Lein and lein javac did the work.
11:43	si14	_ulises: well, what if have just a simple class in my java-source-paths (no packages there)? it seems to work as (import 'TOTP) and (TOTP/main (into-array String [])) , am I missing something?
11:44	_ulises	si14: that should work too, but remember that the default package in Java is discouraged
11:44	augustl	is it possible to create a map where the values are eval-ed when read?
11:45	si14	_ulises: so I should create some directory structure, rename my class and import it under that name?
11:45	augustl	perhaps something that implements IPersistentMap
11:46	_ulises	si14: I'm not saying you should do anything :)
11:46	_ulises	si14: just regurgitating what I know and have read
11:47	_ulises	augustl: you could have closures as values? and then just call them as fns?
11:47	_ulises	,((:foo {:foo (fn [] "foo")}))
11:47	si14	_ulises: you definitely have more knowledge than me in this field, so your advices counts as something I should do :)
11:47	clojurebot	"foo"
11:48	_ulises	si14: well, the default package name is discouraged in java (standard practise) but this doesn't mean you shouldn't do it; I'd probably advise you to organise your code using packages and namespaces mainly because you'll be reading that code later on and will thank your former-self
11:50	si14	_ulises: got it, thanks :)
11:52	_ulises	si14: sure
12:06	konr_trab	What's that function that is like comp but from left to right?
12:07	jackdanger	konr_trab: are you looking for `partial`?
12:07	konr_trab	jackdanger: hmm, I think not...
12:10	_ulises	konr_trab: what are you trying to achieve?
12:11	konr_trab	_ulises: I'm just writing a composite function to be used in a map; it's more convenient to append its posterior functions to the right
12:12	augustl	_ulises: ended up using delays, based on your suggestion, thanks :)
12:13	_ulises	augustl: cool!
12:13	_ulises	konr_trab: so you'd need to reverse the flow to use comp?
12:13	augustl	_ulises: I'll hopefully get to present this to the unconference, if you're going to the conj ;)
12:13	_ulises	augustl: neat! I can't make it this year though :(
12:14	augustl	aww
12:14	konr_trab	_ulises: yes, and I thought there was already a function for it
12:14	_ulises	konr_trab: not sure there is unfortunately
12:46	erwagasore	I am doing koans and I am stuck on multimethod, need help to understand?
12:47	erwagasore	Anybody!
12:47	tomoj	anyone?
12:47	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 ..."
12:48	gauravag	could someone help me in understanding this >> "(iterate f[x] :foo)"
12:48	erwagasore	Here is the function
12:49	erwagasore	(defmulti diet (fn [x] (:eater x)))
12:49	erwagasore	(defmethod diet :herbivore [a] (str "$1 eats veggies." a))
12:49	erwagasore	(defmethod diet :carnivore [a] (str "$1 eats animals." a))
12:49	erwagasore	(defmethod diet :default [a] (str "I don't know what $1 eats." a))
12:49	erwagasore	and this is how I am calling it (diet {:species "lion" :name "Simba" :eater :carnivore})
12:50	erwagasore	what would be the enswer?
12:50	gauravag	erwagasore: isn't this from clojure koan
12:50	gauravag	s*
12:50	gauravag	am doing that just now..
12:50	erwagasore	gauravag yes it is!
12:50	erwagasore	Great, can u share?
12:51	tomoj	the dispatch value is (:eater {:species "lion" :name "Simba" :eater :carnivore})
12:51	erwagasore	Just want to understand. Everything I am putting is not passing the test.
12:51	tomoj	:carnivore
12:52	tomoj	but str doesn't do interpolation like that
12:52	gauravag	(diet {:species "lion" :name "Simba" :age 1 :eater :carnivore})
12:52	gauravag	"Simba eats animals."
12:52	tomoj	also, the argument to the methods, a, is the map
12:53	erwagasore	gauravag does it work?
12:53	tomoj	you need to get the :name out
12:53	gauravag	it worked for me..
12:53	gauravag	I am on
12:53	gauravag	**ex 14 by the way
12:54	tomoj	use str like this: (str "foo's value is:" foo)
12:54	erwagasore	No it is the example 09
12:54	tomoj	no $ interpolation
12:54	gauravag	(defmethod diet :carnivore [a] (str (get a :name) " eats animals."))
12:55	erwagasore	That is not what I have
12:55	erwagasore	(str "$1 eats animals.")
12:56	tomoj	you gave him the answer :(
12:56	erwagasore	What do u mean?
12:57	erwagasore	Oh!
12:57	erwagasore	Hahahahahaha!
12:57	tomoj	note (= (:name a) (get a :name))
12:58	gauravag	tomoj: oops..
12:58	tomoj	well, only part of the answer
13:00	gauravag	but I think this is the part where the power of defining dsl's is most prominent in clojure
13:09	rodnaph_	with enlive is it possible to do multiple transformations in a single match? ie. [:div.foo] [(content "this) (set-attr "that")] (but that doesn't work obv)
13:11	tomoj	gauravag: (iterate f[x] :foo) looks like an error
13:12	gauravag	tomoj: what would be the correct way?
13:12	tomoj	dunno what it's trying to do
13:12	gauravag	(take 100 (iterate (fn [x] :foo) :foo))
13:12	tomoj	oh
13:13	raek	rodnaph_: well, you could repeat the selector like this: [:div.foo] (content "this) [:div.foo] (set-attr "that")
13:13	gauravag	which prints a set of 100 :foo
13:13	tomoj	i.e. (repeat 100 :foo)
13:13	ebaxt	rodnaph_: You can use the do-> macro
13:13	gauravag	yup.. but I wanted to try it using iterate..
13:13	raek	if the transformation functions always return a single new node maybe you can use 'comp': [:div.foo] (comp (content "this") (set-attr "that"))
13:14	gauravag	but the redundant mention of :foo din't seem right to me..
13:14	tomoj	(fn [x] :foo) is also (constantly :foo)
13:14	tomoj	well (iterate identity :foo) works too
13:15	gauravag	tomoj: awesome.. so what is identity?
13:15	tomoj	(fn [x] x)
13:15	gauravag	in that context am I passing identity procedure with a parameter :foo inside iterate?
13:16	tomoj	yeah
13:16	tomoj	(iterate identity :foo) is a seq (:foo (identity :foo) (identity (identity :foo)) ...)
13:16	rodnaph_	ebaxt: will try that thanks.
13:17	gauravag	tomoj: cool.. many thanks.. :)
13:36	dissipate	hi
13:39	gauravag	what is the clojure way of solving this?
13:39	gauravag	(= "Rich Hickey aka The Clojurer aka Go Time aka Macro Killah"
13:39	gauravag	(let [[first-name last-name & aliases]
13:39	gauravag	(list "Rich" "Hickey" "The Clojurer" "Go Time" "Macro Killah")]
13:39	gauravag	(str first-name " " last-name (for [alias aliases] (" aka " alias)))))
13:46	erwagasore	(iterate __ :foo)
13:51	ivan	how do I nrepl-load-current-buffer when I have a new nREPL connection?
13:51	ivan	it always says "Namespace not found" until I close and reopen the .clj file
13:56	Sgeo	How do I make a .DLL visible to my Leiningen project?
13:59	ivan	hm, why is it that when I do (ns otherns) and then (ns user) in nREPL, I lose everything I've added to user?
14:00	ivan	oh, I think it's just spitting old exceptions at me now
14:00	ivan	oh, duh. never mind.
14:01	ivan	debugging lack of pst by calling (pst)...
14:05	ivan	in other news I've been so braindamaged by Python that I thought I'd be able to do (user/pst) from another namespace after (use)ing it in user
14:25	sjl	Is slurp supposed to add a trailing newline even if the file doesn't contain one, or is that a bug?
14:27	AimHere	It doesn't do it for me
14:27	AimHere	Clojure 1.4
14:28	sjl	hm
14:28	sjl	maybe Vim is messing with me then
14:43	Sgeo	http://clojuredocs.org/clojure_core/clojure.core/locking
14:43	Sgeo	What is the "monitor" of a thing, and how do I know if an object has one?
14:45	mudge	anybody here know how to use fs.compression/zip ?
14:46	mudge	or how do I zip compress files using clojure? is there an existing clojure library for this?
15:04	augustl	mudge: I'd just use a java lib for that
15:08	joro	I've repeatedly end up constructing maps like ... (if (is-good e) (assoc m :e e) m). Is there better way to do this?
15:08	callen	joro: well you could make a predicate assoc function that passes a predicate checker and automatically returns the assoc'd map if the predicate returns true
15:09	callen	joro: in a less abstract fashion, if it's a common pattern for specific data, you can just abstract the concrete form of this.
15:09	callen	joro: some specifics about how frequent this is, how much the patterns have in common, etc would be helpful.
15:13	joro	I'm transforming stuff in mongodb on a wire. There is lot of stuff that resembles like this: (if (> new-comments 0) (assoc bare-ex :newComments new-comments) bare-ex)))
15:14	joro	I was wondering that if there is a binding form (like map destructuring) that would make this easier
15:20	tomoj	(test-> bare-ex (> new-comments 0) (assoc :newComments new-comments))
15:20	tomoj	in 1.5.0-beta1
15:23	callen	joro: are you looking for something like what tomoj demonstrated, or something else? please be specific.
15:26	bbloom	test-> is extremely useful!
15:27	bbloom	saw cond-> in codeq, which i think is basically the same thing. said to myself: "why the hell didn't i think of that?" :-)
15:29	joro	what is the third argument of test->?
15:34	sunkencityryleh	mmmm… multimethods. cleaning up some code with multi methods. this is good stuff.
15:35	callen	sunkencityryleh: example? :D
15:35	callen	sunkencityryleh: also, love the name.
15:36	Sgeo	Suppose I'm writing an event-based library
15:36	Sgeo	Would it make sense to expose to event handlers a stop-handling function that they can call to remove itself from the list of event handlers?
15:37	sunkencityryleh	callen: I had an array of hashes and a fn as one of the keys, now I have the methods separate and just switch on a key. I send in the same hash but I have added some match data to it. This is beginning to look like pythons OO.
15:41	callen	Sgeo: I hate to punt the ball like this, but this is something you'd really want to look into by examining Lamina.
15:42	callen	my initial instinct is "no" unless a specific use-case cries out for it.
15:43	Sgeo	Pretty sure that some use cases cry out for a nice way to have an event handler remove itself, but not sure if that's the best way to do it
15:43	ivan	Sgeo: well, what else could you do?
15:44	Sgeo	I could pass the function into the handler like an argument, or I could just have the function I call to set up the handler return the function to stop handling, and whenever I want a handler to remove itself, use promises to make it accessible to the handler
15:45	Sgeo	Last one's inconvenient to use raw but could be a building block'
15:45	raek	Sgeo: I think so. some network protocols have commands that form temporary "dialogs". in those cases you might want to use a state machine that listens for certain commands, but only for a limited lifetime
15:46	raek	one example is the IRC login process
15:46	Sgeo	I'm thinking more ... IRC-bot-like thing except for a particular 3d world
15:47	ivan	this could become a mess with code reloading
15:47	Sgeo	Ah, hmm
15:47	raek	I like how IObservable does it in .net: when you subscribe you get an instance of IDisposable back. when you call dispose on it, it deregisters the callback
15:48	raek	no need to carry around ids/keys like in Clojure's add-watch/remove-watch
15:49	Sgeo	What sees the IDisposable?
15:50	raek	the code that registers the callback
15:50	Sgeo	Ah
15:50	Sgeo	Well, the question is how to make the callback itself be able to deregister itself
15:50	Sgeo	It's easy enough to return to the registrating code a function that will deregister the callback
15:50	raek	ah
15:51	raek	in Haskell, you could let the callback close on the result of the subscribe operation :)
15:52	raek	but in Clojure variable bindings have to be causal...
15:54	raek	Sgeo: what is your library like compared to Lamina, Cljque, and RX in .Net?
15:55	Sgeo	Haven't looked at Cljque
15:56	Sgeo	There's an event for when someone says something, an event for when someone joins, someone leaves, etc. etc.
15:56	Sgeo	Someone clicks something
15:58	raek	I wonder if anyone has made a Clojure library for Functional Reactive Programming...
15:59	mudge	how do a load a file from disk into a lazy byte array?
16:00	raek	mudge: Clojure (and Java) does not have any type for lazy byte arrays. you could make a lazy sequence of bytes, though...
16:01	mudge	raek: thanks
16:01	callen	mudge: why does it need to be lazy?
16:01	mudge	callen: well I need to read a file into a byte array --- if the file is large then I need to load the entire file into memory, but if it is lazy then I don't
16:02	mudge	callen: that's my theory anyway
16:02	Sgeo	Even Haskell discourages lazy I/O
16:02	mudge	Sgeo: why?
16:03	raek	mudge: how will you process the bytes?
16:03	raek	mudge: anyway, if you need a lazy byte seq, you can do it like this: https://gist.github.com/661631
16:03	Sgeo	mudge, because the time of closing the file might be unknown, what if you close it too early, or never close it, etc.'
16:03	mudge	reak: I'm making one zip file of various files.
16:03	raek	pass it an input stream, for example one created by clojure.java.io/input-stream
16:04	raek	in Clojure you can wrap the whole code that will potentially touch the seq in a with-open form
16:05	raek	the problem lies in the "that will potentially touch the seq" of course...
16:08	raek	Sgeo: does Haskell discourage lazy I/O in general or only "lazy resource management"?
16:08	Sgeo	raek, hmm, not sure
16:09	mudge	what's the best way to read a binary file into a byte array?
16:10	raek	mudge: use the methods of the java.io.InputStream class
16:10	mudge	Raek: okay, thanks
16:13	raek	mudge: you can use the gist I linked previously as an example. just replace the (lazy-cat ...) part with whatever you need to do with the bytes
16:13	tomoj	(let [out (java.io.ByteArrayOutputStream.)] (io/copy in out) (.toByteArray out))
16:13	tomoj	??
16:13	lazybot	tomoj: Definitely not.
16:14	augustl	any suggestions for a in-process database that stores to a specified path in a local file system?
16:14	augustl	datomic free fits that description, right?
16:14	mudge	raek: can you send me the URL again?
16:14	tomoj	datomic free is not exactly in-process
16:14	augustl	new to the JVM so not sure what's available
16:14	tomoj	the free transactor is a separate process
16:14	raek	mudge: sure: https://gist.github.com/661631
16:14	augustl	tomoj: hmm, I thought the transactor local storage was in-process
16:14	augustl	ah I see
16:15	tomoj	in process you only get memory 'storage'
16:15	raek	tomoj's version does the same thing, but reads the whole file into one big array
16:15	raek	mudge: are you using the java classes for the zipping?
16:15	augustl	tomoj: I see
16:16	mudge	raek: I am via this library: https://github.com/Raynes/fs/blob/master/src/fs/compression.clj
16:16	tomoj	theoretically you should be able to run the free transactor in the same process, I think
16:16	tomoj	but it is not supported yet
16:16	mudge	raek: i'm using the file system clojure library
16:16	tomoj	you don't get a pom for the free transactor
16:17	mudge	reak: for zipping I have to get the bytes of each file and associate it with a file name
16:17	augustl	tomoj: hmm I see
16:17	augustl	tomoj: I'll be shipping uberjars/uberwars so a pom isn't that important actually
16:17	raek	mudge: wait, there's a better example in the clojure source: https://github.com/clojure/clojure/blob/master/src/clj/clojure/java/io.clj#L296
16:17	augustl	it's a standalone application that you just start with java -jar ...
16:17	Somelauw	I just installed leiningen through package manager, but what does it need a lot of dependencies?
16:18	mudge	thanks raek
16:18	Somelauw	also it needs clojure as a dependency, whereas its goal is to install leiningen
16:18	tomoj	augustl: well, you could try adding all the jars in the transactor lib/ (manually - no pom), and then you'd have to figure out how to start it
16:18	raek	mudge: using the java api (which fs uses) you can do this by looping and reading/writing fixed sized arrays
16:18	augustl	tomoj: I'll investigate, thanks
16:19	mudge	raek: so that the entire file doesn't have to be read into memory?
16:19	mudge	at the same time
16:19	raek	mudge: yes
16:19	mudge	raek: that sounds good
16:20	tomoj	looks like there is a transactor pom hidden in datomic pro
16:20	raek	mudge: I'm not sure if/how 'fs' can do this. Raynes (the author) is frequently in this channel, so maybe you can ask him directly
16:21	mudge	raek: okay, thanks
16:21	mudge	Raynes: you around?
16:21	raek	mudge: you can probably find an example that does what you want written in Java somewhere and then translate it into Clojure
16:22	mudge	raek: that is a good idea, I'll search for that now
16:23	raek	mudge: the approach would basically look like this:
16:23	amalloy	man, java.util.zip. what a mess
16:23	raek	yeah...
16:24	raek	open output zip file. for each file: open input stream from file, open output stream to zip entry, copy data in chunks (clojure.java.io/copy does this)
16:24	mudge	raek: amalloy: seems like the best zip function would be a function that takes a filename and a directory name and zips everything in the directory to the file name
16:24	amalloy	mudge: why bother if you want something that generic? just shell out to tar+gzip, or zip, or whatever
16:25	amalloy	zipping directories is a solved problem :P
16:25	raek	mudge: if you can rely on certain executables being available where you run the progeam, perhaps it's simpler to just use an external program
16:25	amalloy	(but i bet you apache commons io has a decent java solution)
16:25	mudge	raek, amalloy, yea sounds good
16:27	mudge	amalloy: is apache commons in the maven website repository?
16:27	mudge	sorry if I sound silly, i'm just getting into all this
16:27	amalloy	certainly
16:28	amalloy	most reasonable java libs are, and especially those run by the people who run maven
16:31	raek	mudge: an example of how to use the zip classes (in Java): https://gist.github.com/4056327
16:31	Somelauw	When doing % lein run
16:31	raek	it only writes a single file, but I think you get the idea
16:31	Somelauw	"No :main namespace specified in project.clj" is what I get.
16:32	mudge	raek: i get the idea, thanks
16:34	Somelauw	nvm, I think I got it to work
16:35	Somelauw	Well I added to project.clj ":main myproject.core", so that should work?
16:36	Somelauw	But I get Exception in thread "main" java.lang.RuntimeException: java.lang.ClassNotFoundException: myproject.core
16:38	Somelauw	fixed it
16:38	raek	Somelauw: and you have a file called src/myproject/core.clj ?
16:39	callen	is anyone here familiar with the template inheritance structure Refheap uses with Stencil?
16:39	callen	I'm finding it a little difficult to track everything that's going on.
16:39	Somelauw	raek: yes, i only forgot to create a -main method in that file
16:39	Somelauw	or actually I named it main- instead
16:40	sunkencityryleh	Just finished a little clojure project for converting textile to hiccup. It seems to work, but I'll have to test it out for real.
16:40	callen	sunkencityryleh: write a fuzzer.
16:40	sunkencityryleh	I'd love to get some feedback on what I could do better in the code
16:40	sunkencityryleh	https://github.com/sunkencity/dr-textile-and-mr-hiccup/blob/master/src/dr_textile_and_mr_hiccup/core.clj
16:40	callen	sunkencityryleh: oh that explains the multimethods. But seriously, write a fuzzer that generates valid textfile.
16:41	callen	textile*
16:41	sunkencityryleh	what's a fuzzier?
16:41	callen	sunkencityryleh: http://en.wikipedia.org/wiki/Fuzz_testing
16:41	callen	I use it all the time in my unit-testing. It bares a measure of resemblance to how QuickCheck works, although it's a lot more specific.
16:42	sunkencityryleh	ah, like the test quickcheck
16:42	callen	'ish.
16:51	augustl	is there a public version of this around? https://github.com/ring-clojure/ring/blob/860fbdd825b4fbe83ec67dad4009ce7bc0b0117a/ring-jetty-adapter/src/ring/adapter/jetty.clj#L12
16:51	augustl	want to create a servlet for my ring handler, without actually starting a server in the same step
17:00	dissipate	what's the quickest and easiest way to get started learning clojure?
17:02	joro	dissipate: I bought Emerick's "P in C", and started writing a mid-sized clojure program.
17:03	dissipate	joro, link to book?
17:04	joro	there might be other good books also around, I chose that by reviews and pragmatism
17:04	Bronsa	dissipate: http://www.clojurebook.com/
17:05	dissipate	Bronsa, are you sure that isn't a reference book?
17:05	Bronsa	yeah.
17:06	joro	the most difficulties I've had in error handling, debuggin, and lately, debugging stm stuff.
17:07	joro	maybe tooling is an issue, if you are not used to emacs?
17:07	callen	dissipate: it's not a reference book.
17:08	callen	The main issue I've been having with Clojure, and yeah, I know this is silly...HTML templating
17:08	callen	Stencil, Enlive, and Hiccup all make me deeply unhappy.
17:10	dissipate	clojure doesn't seem to have many web frameworks available for it. that could be a bonus actually. :D
17:10	joro	I'm quite happy with ring, compojure, and pure REST
17:11	Raynes	dissipate: There are no 'reference' books for Clojure.
17:11	dissipate	Raynes, that's strange
17:12	rodnaph_	callen: that's surprising to hear. i really liked hiccup, but have fallen for enlive over it now.
17:12	Raynes	I'm not sure how.
17:12	dissipate	rodnaph_, are you doing web programming with clojure?
17:13	rodnaph_	yeah, pretty much everything i've done with clojure is web focused (or at least has a web frontend)
17:13	dissipate	rodnaph_, interesting
17:14	rodnaph_	dissipate: i'm finding compojure + enlive a really great combination. for UI and API stuff
17:14	Raynes	Enlive gives me hives. I'm partial to mustache.
17:14	dissipate	rodnaph_, what are the benefits of web programming in clojure vs. say a python framework like django?
17:14	callen	rodnaph_: I've only been able to make progress thanks to Raynes' refheap as a reference for how to do the mixture of partials in Stencil.
17:15	callen	rodnaph_: I still find mustache to be pretty freakin' weak compared to Jinja though.
17:15	Raynes	<3
17:15	Raynes	I think the fact that it is weak is why I like it. Simple is nice.
17:15	callen	Raynes: no seriously, playing "follow along" with refheap has been a MASSIVE boon to making a web app in Clojure. I've not had any serious breakage since I started simply because I was able to learn from your code.
17:16	dissipate	what are the benefits of doing web apps in clojure?
17:16	Raynes	Happy to hear it.
17:16	tomoj	enlive seems simpler
17:16	callen	well the weakness means falling back to defining partials in terms of Clojure code. The iterable behavior is questionable too. That's more coupling between HTTP runtime/template-side than I like to see.
17:16	Raynes	dissipate: The benefits are that you get to use Clojure instead of Python.
17:16	callen	dissipate: for me? Almost none. Purely pedagogical. Web apps are what I know.
17:16	rodnaph_	dissipate: i've never used django, but have lots of other frameworks in various languages, and the benefit i find is purely clojure. if you feel more comfortable with frameworks then maybe it's not right for you.
17:16	callen	dissipate: I'm 1000% more productive in Python/Flask/Jinja than I am in Clojure right now. Might change eventually.
17:16	Raynes	And if you ask "what are the benefits of Clojure over Python", I'm going to find you and cause you harm.
17:17	callen	my python stack isn't more productive because of Python, it's more productive because of Flask and Jinja.
17:17	dissipate	Raynes, yikes!
17:17	Raynes	:p
17:17	callen	Noir sorta'ish covers the Flask use-case, but Jinja still isn't really provided for yet.
17:17	callen	Monger is a perfectly acceptable replacement for MongoEngine (better, even)
17:17	dissipate	Raynes, i'm coming from Python, but i'm very interested in the benefits of pure functions and transactional state memory
17:17	callen	so the biggest hits to my productivity come from unfamiliarity and the lack of a jinja equivalent.
17:17	Raynes	I want a driver for rethinkdb.
17:18	callen	dissipate: I'm only here for the Lisp.
17:18	rodnaph_	when you're comfortable with clojure, i think the simplicity is refreshing. i've found what i thought made me productive in other frameworks, i simply don't need in clojure.
17:18	callen	Raynes: writing a driver for rethinkdb could be interesting, since it has like 3 different query langs.
17:18	callen	I'm an ex-CL'er trying to get back on the horse, so to speak.
17:18	dissipate	rodnaph_, how easy is it to become 'comfortable' with clojure? :O
17:18	Raynes	callen: I've got taking a shot at it on my TODO list.
17:18	wink	anyone seen any clues how to do it? I wondered if they're even open to 3rd-party-drivers
17:19	Raynes	wink: It looks like it is done over sockets. You can look at the implementations in the repo.
17:19	callen	Raynes: I use MongoDB as well, I see you're as excited as I am about replacing MongoDB? :P
17:19	Raynes	callen: I'm excited about not having to hear people bitch because I use mongodb.
17:19	Raynes	That's about it.
17:19	dissipate	callen, what's wrong with MongoDB?
17:19	rodnaph_	dissipate: i won't lie, i found moving to FP a bit of a struggle. but mostly because i was overcomplicating things in my mind i think. use it 100% on a project and i reckon within a week you'll be flowing.
17:20	callen	Raynes: who complains?
17:20	Raynes	Lots of people.
17:20	wink	Raynes: ok, I failed to find a repo. very cursory glance it seems. thanks :)
17:20	callen	Raynes: you made a free pastebin designed for Clojure users. Is that what they bitch about? refheap using it?
17:20	rodnaph_	dissipate: (but then throwing out everything you did a week later, hehe)
17:20	callen	dissipate: a lot of stuff that matters about 10% of the time.
17:20	Raynes	callen: Mostly long discussions about how terrible mongodb is whenever I've ever mentioned how refheap uses it.
17:20	dissipate	i'm using mongodb for a small project
17:21	dissipate	i like the flexibility
17:21	callen	Raynes: Refheap is the sort of thing MongoDB is perfect for, thugh.
17:21	Raynes	Which I am completely and utterly uninterested in, given that mongo works fine for this project.
17:21	callen	dissipate: it's great for that. Just don't suggest using it at work.
17:21	dissipate	callen, someone is already using it at work. :P
17:21	wink	refheap isn't supposed to be a consistent transactional DB though :P
17:21	callen	I use it at my startup, but that's due to 1. Legacy code 2. I know the trade-offs and it doesn't matter for us.
17:22	dissipate	someone is using MongoLabs at work actually
17:22	callen	you know of all the trade-offs that bother me with MongoDB, I have to say that transactions has come up for me approximately zero times.
17:22	Raynes	callen: https://github.com/weavejester/comb An old templating lib.
17:22	dissipate	are the complaints with mongodb related to scalability or what?
17:22	unnali	callen: it's come up for us about a hundred times. I think it really just depends on your domain/what you're doing.
17:23	callen	Raynes: I managed to get things working with stencil, thanks to you refheap/views folder, but it feels a bit creaky. As if I'm going to run into pain later if I need to spread out my template inheritance or something.
17:23	callen	unnali: yeah I work in consumer web apps, so for me it just rarely if ever matters.
17:23	callen	unnali: knowing that the option isn't available is...disconcerting to say the least.
17:23	Raynes	callen: Admittedly, refheap's templates are a mess that could probably be cleaned up.
17:23	callen	the thought of having to implement a lock-batch-unlock mechanism makes me weep.
17:24	Raynes	callen: Jinja looks interesting. Has a built in sandboxed execution environment. Why is that useful?
17:24	callen	Raynes: they were a little hard to follow until I understood that you were implementing a partials system on top of Mustache's pseudo-partials system.
17:24	Raynes	Do people not sanitize user input?
17:24	callen	Raynes: having it baked into the templating system does a lot to prevent issues.
17:25	Raynes	Mustache partials are less useful than doing it in the Clojure code itself.
17:25	callen	Raynes: the best way to explain Jinja is to realize that I am rarely writing templates except as an initial "example" showing what the name of the data getting injected looks like, then handing it off to the frontend guy.
17:25	callen	Raynes: the blocks/template inheritance system in Jinja is something the frontend guy can understand and work with without bugging me
17:25	Raynes	Right, makes sense. I don't have a frontend guy for my personal projects.
17:25	callen	Raynes: having to reach into my Clojure code is highly sub-optimal.
17:26	callen	Raynes: right, but that's a common issue in clojure projects. No accommodation/thought for division of labor.
17:26	Raynes	I had to work with a frontend guy for the first time a while back.
17:26	Raynes	I was like an encyclopedia answering questions.
17:27	akhudek	In an ideal world, the frontend and backend would both be clojure. ;-)
17:27	callen	Raynes: how do you mean?
17:27	callen	akhudek: not really, people specialize their knowledge into HTML/CSS/JS because those are subjects that often merit their own hooman in larger projects.
17:27	callen	learning clojure is, frankly, out of the question.
17:27	Raynes	I mean he asked me lots of questions. Lots and lots of questions. It wasn't actually a website, but an API that he had to implement a frontend for.
17:28	akhudek	callen: HTML/CSS/CLJS. Just replace Javascript with ClojureScript. I don't see why learning clojure is out of the question for a javascript programmer, but not for a java programmer.
17:28	Raynes	Anyways, Jinja looks cool. I might argue with the "Jinja is Beautiful" tagline, but nonetheless..
17:30	callen	akhudek: you know what, give it a whirl. See how the JS dev reacts.
17:31	callen	Raynes: Jinja is something that came out of the post-PHP/JSP era. In that context, it's heaven itself.
17:31	Raynes	ClojureScript seems like a tiny bit of a pain in the ass to use. Unless those js devs really hate js and really would rather use Clojure, I don't think you'll have much luck.
17:32	dissipate	what is clojurescript used for?
17:32	rodnaph_	i've only started using enlive today, but it really feels like an improvements on templating "languages"
17:32	Raynes	dissipate: It's a Clojure implementation that compiles to Javascript.
17:33	dissipate	interesting
17:33	dissipate	sounds like coffeescript
17:33	akhudek	callen: I've taught two student javascript programmers clojure. It wasn't too hard. And Raynes, JS devs seem to really like Coffeescript. I don't think they are opposed to new languages in general.
17:33	callen	akhudek: I'm talking about working with experienced professionals who have a lot invested in their skillset
17:33	callen	akhudek: not undergrand randos with time to burn.
17:35	akhudek	callen: the argument is still the same as any other experienced developer. You may as well advocate the same thing about Java and thus people shouldn't learn clojure.
17:35	callen	erm, no.
17:35	callen	Backend is different. You can use anything you want there.
17:35	callen	You will never ever ever escape HTML/CSS/JS on the frontend in web.
17:35	clojurebot	Huh?
17:35	callen	you can try to hide it with coffeescript, cljs, or whatever, but you'll never fully escape it.
17:35	callen	Not even close.
17:36	callen	akhudek: you're just grasping at straws now. Let it go.
17:36	dissipate	callen, how did google escape it? JS is not an official google language. :P
17:36	matt444	I have a deeply nested vector that I would like to "reach into" and modify. What functions should I be using?
17:36	callen	dissipate: they didn't, JS is a large component of their work.
17:37	callen	dissipate: I know a Google employee who's one of the principals on AngularJS.
17:37	dissipate	callen, did they not 'escape' via GWT?
17:37	callen	no, that failed horribly.
17:37	amalloy	matt444: update-in and assoc-in
17:37	callen	they still use it in bits and pieces, especially on older properties.
17:37	callen	They abandoned it for newer projects.
17:37	dissipate	google is using pure JS on new projects?
17:37	dissipate	yikes
17:37	matt444	amalloy, assoc-in is the one I was thinking, thanks!
17:37	callen	the Google Closure ecosystem is a more accurate representation of how they do things.
17:37	dissipate	here comes Dart!
17:37	akhudek	callen: if your argument is that compiling to JS is bad in general, I suspect there are many that would disagree.
17:37	callen	akhudek: no, that's not my argument.
17:38	callen	akhudek: jesus, stop making shit up just to try to make an argument you don't have the experience to be making.
17:38	Raynes	Eh
17:38	Raynes	You don't really have to be so harsh.
17:38	callen	I don't like having words put in my mouth just so people can make themselves look less stupid at my expense.
17:39	Raynes	I'm pretty sure the channel is here for discussion.
17:39	dissipate	akhudek, it is bad. JS is the bain of web programming.
17:39	callen	Especially on IRC when it's textual and there's really no excuse. You can take your time to read what I said before tossing random stabs at getting the advantage.
17:39	callen	dissipate: bane.
17:39	callen	dissipate: bain is a name.
17:39	dissipate	callen, you are right, bane. :P
17:40	callen	Raynes: you're right, that was too harsh, but I lost interest in the argument several lines prior. Despite that, I get dragged back in because I have to fend off obviously ridiculous assertions as to what I meant so I don't look like the complete ass he was trying to make me into.
17:40	callen	Raynes: I'll attempt to fend off the ridiculousness with a more polite and cheerful tone in future.
17:40	Raynes	Sounds good.
17:40	dissipate	has anyone 'big player' in web considered using a browser virtual machine that can run byte code compiled from many different languages? e.g. the Parrot VM
17:41	callen	dissipate: impractical.
17:41	dissipate	callen, how so?
17:41	callen	dissipate: well for one thing, a browser VM runtime has been done, it was called Flash.
17:42	amalloy	callen: nobody could put words in your mouth if you weren't constantly starting arguments unrelated to clojure in here
17:42	callen	dissipate: for another, you'd be introducing an immense amount of complexity for little gain. Performance is another concern.
17:42	dissipate	callen, so what is the solution? javascript is clearly a problem.
17:43	callen	amalloy: to my credit, I was originally talking about stencil, hiccup, and enlive. The general subject of front-end work eventually nose-dived into what you saw.
17:43	callen	dissipate: I don't agree with the premise.
17:43	dissipate	callen, JS is perfectly fine? :O
17:43	callen	that's not the way I'd put it.
17:44	callen	I think JS is fine for what it's meant to do and that compiling into it from things like cljs is a fine way to ameliorate the pain if you don't like JS.
17:44	callen	or coffeescript, or roy, fay, etc.
17:44	dissipate	callen, the problem with JS is that it sucks for building larger apps
17:45	callen	dissipate: what large apps have you built?
17:45	Raynes	This is why I never argue about javascript.
17:46	dissipate	callen, i'm currently working on electrosim.com, a browser based schematic capture and simulator for electrical engineers.
17:46	callen	Whether or not JS scales up to a large project depends a great deal on factors that have little do with JS. Like testing, linting, code standards, libraries, etc. That's true of any programming language and any project.
17:46	callen	dissipate: the Google Closure ecosystem shows some good ways to scale JS up for larger projects.
17:47	tomoj	what a coincidence
17:47	callen	tomoj: ?
18:05	cshell_	Is lein 2.0 backwards compatible with 1.7.x projects?
18:22	akhudek	cshell_: no, but there is some package that will try to auto-update a project to some extent
18:24	Raynes	cshell_: No, but every project you'll ever care about (except your own, I guess) has updated.
18:25	akhudek	cshell_: https://github.com/technomancy/leiningen/wiki/Upgrading
18:26	cshell_	thanks guys - I'm trying to work on the IDEA Leiningen Plugin and trying to figure out if I should support both 1.7+ and 2.0
18:26	cshell_	or if I should just support 2.0
18:26	Raynes	I'd just support 2.0.
18:27	cshell_	Yeah, that would make my life easier - and I could just tell people how to update their current projects from 1.7 to 2.0
18:27	Raynes	Supporting 1.7 encourages continued using 1.7 which we shouldn't do, and opens up a huge can of annoying worms for you.
18:27	cshell_	good point
18:27	Raynes	But really, pretty much nobody is still using 1.7, so I think you're safe.
18:27	akhudek	Also, as Raynes said, there are very very few 1.7 projects still around.
18:27	Raynes	Eclipse, for example, uses lein2 I think.
18:28	amalloy	Raynes: spinning laziness as community activism since 2011
18:28	Raynes	Damn right.
18:29	cshell_	Okay great, I'll go with 2.0 then - the leiningen-core library makes my life a lot easier as well
18:29	Raynes	My life skills include landscaping and making people feel like their laziness is beneficial in the end.
18:35	cshell	I guess the only people using 1.7 are those who are still using the leiningen plugin in IDEA :)
18:36	Sgeo	Ugh, the C wrapper I'm wrapping takes callbacks as functions, and any sane Clojurey API, which I intend to make, would take the callback as a function, but the JNAerated Java, of course, doesn't.
18:49	Hodapp	wellll, I had to go all the way to Emacs to get Clojure support that would (1) give me syntax highlighting in the editor, (2) let me send expressions in the editor buffer to a REPL, and (3) let me type things in the REPL
18:49	Hodapp	but I'm finally there
18:51	Raynes	You could get that from Light Table too.
18:51	Raynes	Pretty sure Eclipse makes it easy as well.
18:51	Raynes	And there is catnip.
18:51	mudge	Raynes: hi!! I've been using your file system clojure library today
18:51	Hodapp	Raynes: Eclipse & Counterclockwise gave me a bunch of crashy bullshit.
18:52	Raynes	mudge: Yo.
18:52	Hodapp	Raynes: It worked okay for a bit, and then it didn't.
18:52	Raynes	Hodapp: That's okay, I don't like Eclipse either.
18:52	Hodapp	Raynes: It's nice for Java stuff. At least as far as Java stuff goes.
18:52	Raynes	But if you don't dig Emacs, give light table a shot. It isn't perfect, but it's making excellent progress.
18:52	Hodapp	I'm liking Emacs, actually. But I did watch the video on Light Table months and months back and it looks like some very cool software.
18:53	Raynes	Catnip looks pretty neat too, if you just want a Clojure editor.
18:53	mudge	Ryanes: I was looking at using the zip function in fs.compression but it looks like I need to load the entire files into byte arrays for use by make-zip-stream, does this sound right?
18:53	akhudek	Hodapp: I'm one of the few here who like IDEA + La Clojure.
18:53	Hodapp	akhudek: I had mixed luck with IDEA.
18:54	Raynes	akhudek: The file contents have to be either strings or byte arrays.
18:54	Raynes	Er.
18:54	Raynes	mudge: ^
18:55	Raynes	But having to load the entire file into memory sounds bad.
18:55	Raynes	mudge: I would expect that your byte array could be lazy. At least, I hope that's the case. I didn't actually write those functions.
18:56	Raynes	Having to load entire files into memory is a bug, so open an issue about it if it turns out to be the case.
18:56	mudge	Raynes: I see
19:01	mudge	Raynes: okay thanks. Well make-zip-stream expects arguments like this: [[filename1 content1][filename2 content2]...] and the content1 variable is passed to ZipOutputStream.write() which expects a Java byte array, which I'm thinking can't be lazy because Java byte arrays are not lazy
19:01	Raynes	Ugh, an actual byte array.
19:01	Raynes	Yeah, this is the devil.
19:08	mudge	Raynes:, raek: I wrote my own implementation of zip that makes a zip file of all files in a directory: https://gist.github.com/4056821
19:16	gfredericks	has clojure.java.jdbc had major breaking changes since the contrib days?
19:31	wink	gfredericks: hm, it's definitely different, can't say how different
19:37	gfredericks	is it possible to tell lein not to do anything with the internet even though my project has snapshots?
19:48	TheShellfishMeme	I'm trying to learn clojure at the moment. To understand macros better I decided to make one that makes all calls to '*' return x times the result. I first wrote the code that does this directly with a fixed
19:48	TheShellfishMeme	hit wrong button :/
19:50	TheShellfishMeme	… with a fixed multiplier. then I tried to convert it into a macro, but I keep getting a IllegalArgumentException Don't know how to create ISeq from: clojure.lang.Symbol clojure.lang.RT.seqFrom (RT.java:494) error no matter how much I simplify it. Can someone help me and point me in the right direction? Code: http://pastebin.com/2VApsqnp
19:52	tmciver	TheShellfishMeme: Well, you forgot a name for the macro.
19:52	TheShellfishMeme	yeah I just realized that as well
19:53	TheShellfishMeme	facepalm
19:54	TheShellfishMeme	thanks :)
19:54	tmciver	np. It happens to the best of us.
19:55	gfredericks	(defn println [& args] (apply clojure.core/println (if facepalm (concat args ["duh."]) args)))
20:02	mattis	what is the preferred way to talk to a socket from Clojure? I see quite a few using the Java classes directly, but clojure.java.io looks more functional
20:17	TheShellfishMeme	now I have the problem that it says "Can't let qualified name" http://pastebin.com/kQbq0Ac0. I tried to do some research into what causes this, but I don't think I quite got it yet. Ignoring that this is nothing one would actually want to do in a real program, what is it that causes this error and how can I get around it?
20:18	cshell	change * in the binding to *#
20:19	cshell	(defmacro moretimes [times body] `(let[# #(apply (conj %& ~times))] ~body))
20:20	TheShellfishMeme	but then it doesn't seem to do anything. something else I missed there?
20:20	cshell	what do you expect (moretimes 2 (* 1 2)) to expand to?
20:22	TheShellfishMeme	actually it does what I want but it's getting late and I didn't notice the "1" in there.
20:22	TheShellfishMeme	or does it?
20:23	TheShellfishMeme	actually I wanted (moretimes 2 (* 2 2)) to expand to (let[* #(apply * (conj %& 2))] (* 2 2))
20:23	TheShellfishMeme	which should evaluate to 8
20:24	TheShellfishMeme	but (moretimes 2 (* 2 2)) evaluates to 4, so I guess something isn't working there
20:24	cshell	why are you shadowing the clojure/core/* operator?
20:25	gfredericks	he's messin with macros
20:25	gfredericks	you either want to shadow with (let [~'* ...] ...) or you want to use with-redefs, depending on your exact goal
20:25	TheShellfishMeme	because I have no idea what I am doing :) needed to find some kind of example use for them, so I came up with this
20:26	gfredericks	TheShellfishMeme: did you want the effect to be just in the code that's lexically inside of moretimes?
20:26	gfredericks	or all code executed even indirectly?
20:26	TheShellfishMeme	yes exactly
20:26	TheShellfishMeme	just inside moretimes
20:26	gfredericks	then you want to shadow with (let [~'* ...] ...)
20:26	gfredericks	that causes any * inside the macro to refer to your local function instead of the clojure.core var
20:27	TheShellfishMeme	hah, perfect. thanks a lot
20:27	gfredericks	it's syntactically ornery because that sort of thing is rarely what you want to do in a macro
20:27	gfredericks	(shadowing)
20:29	TheShellfishMeme	yes, I thought so. felt weird writing this code, but I needed some kind of thing to implement. just reading about macros didn't really help the understanding
20:30	cshell	Just think of macros as functions that return Clojure code
20:30	tmciver	TheShellfishMeme: you realize that you don't need to shadow * here; you could replace it with something like my-sym# everywhere.
20:31	tmciver	or my-times#, say.
20:31	TheShellfishMeme	yes I do understand that. but I learned a lot more doing it the ugly way :)
20:34	TheShellfishMeme	I swear I'll never use this kind of thing in real code
20:35	Iceland_jack	Only in imaginary code
20:38	gfredericks	or at worst complex code
20:41	TheShellfishMeme	complex code is an integral part of lambda calculus
20:42	TheShellfishMeme	I'll show myself out
20:43	TheShellfishMeme	anyway, thanks for your help.
20:43	penryu	I've seen both (cons foo (lazy-seq ....)) and (lazy-seq (cons foo ...)) forms; which is better/best? or what are the caveats of each?
20:44	gfredericks	the latter won't evaluate foo until needed
20:45	gfredericks	if foo already exists I don't know any reason to use the latter
20:45	penryu	so not even the head of the returned seq will be eval'd until needed?
20:45	gfredericks	there's probably something though. I always don't think of something.
20:45	gfredericks	right
20:45	gfredericks	lazy-seq just thunks everything and does nothing until you need it to
20:46	penryu	okay. that makes sense.
20:46	penryu	so the latter is closer to haskell, iiuc
20:47	gfredericks	I spose
20:47	penryu	hrm. that comparison seems less and less useful the more I think about it.
20:48	gfredericks	:)
20:49	gfredericks	clojure: it's like haskell but only for lists some of the time
20:51	amalloy	gfredericks: ##(realized? (iterate inc 1)) is one reason you might prefer the latter
20:51	lazybot	java.lang.ClassCastException: clojure.lang.Cons cannot be cast to clojure.lang.IPending
20:51	gfredericks	I was half considering mentioning that 85% of the time that I miss something amalloy or hiredman will point it out
20:51	rafb3	would like feedback on this content about functional programming I've been working on for a talk...
20:52	rafb3	https://github.com/rafaelbandeira3/The_Stateless_Server_pt-BR/blob/master/the_stateless_server_en.markdown
20:52	rafb3	feel invited to comment on it there
20:54	penryu	amalloy: are you referring to the change in behavior of (realized? (iterate inc 1)) and (realized? (rest (iterate inc 1)))?
20:54	amalloy	yeah
20:55	penryu	good point
20:55	penryu	so that's two points in favor of the lazy-seq-over-cons routine
20:57	gfredericks	well it's a conceivable reason to use that; I don't think it's a reason to prefer it generally
20:59	penryu	in the case of iterate, it's not really important either way, I believe. if the seeding of the sequence were expensive, you might choose one or the other to try to perform/delay the operation as desired
20:59	penryu	and indeed, all the docs use cons->lazy-seq
21:00	penryu	but the argument for consistency is a strong one, but maybe not very important in practice?
21:01	gfredericks	consistent with what? most sequences don't respond to realized?
21:01	gfredericks	e.g., lists
21:01	penryu	good point
21:02	gfredericks	it only makes sense in a context where laziness is expected for some odd reason
22:21	cshell	Can anyone tell me why (drop-while #(not= % "--to-dir") '("myprj" "--to-dir" "c:/temp/yyy11")) returns ("--to-dir" "c:/temp/yyy11")?
22:22	cshell	,(drop-while #(not= % "--to-dir") '("myprj" "--to-dir" "c:/temp/yyy11"))
22:22	clojurebot	("--to-dir" "c:/temp/yyy11")
22:24	cshell	,(take-while #(not= % "--to-dir") '("myprj" "--to-dir" "c:/temp/yyy11"))
22:24	clojurebot	("myprj")
22:25	cshell	,#(not= "c:/temp/yyy11" "--to-dir")
22:25	clojurebot	#<sandbox$eval85$fn__86 sandbox$eval85$fn__86@6fc1049d>
22:25	cshell	,(#(not= "c:/temp/yyy11" "--to-dir"))
22:25	clojurebot	true
22:29	cshell	ohhh.starting from the first item
22:29	cshell	oops