#clojure – 2014-08-10

2014-08-10

00:00	lpvb	jeremyheiler: sometimes there's a lot of computations and constants in the let form and I want to declare what I need closer to the functions that need them so putting it directly in the let vector next to them makes it look better to me
00:01	lpvb	that and also I know whatever has a _ before it is definitely a side effect
00:01	lpvb	and my nil returns are explicit
00:01	lpvb	idk
00:01	jeremyheiler	cool. i've done the _ thing with temporary printlns and whatnot
00:02	jeremyheiler	but i otherwise don't find myself doing a lot of side effecty things in a let
00:02	jeremyheiler	in a let binding*
02:40	Jaood	amalloy_: did you switch computers?
03:06	amalloy	Jaood: what? when?
03:40	bluesnow	Hi, I installed the counterclockwise plugin for Eclipse, but when I go to File -> New -> Project -> .., I don't see the Clojure Project option.
03:40	bluesnow	Any idea what I might be missing?
04:13	katratxo	bluesnow: it's File > New > Clojure https://i.imgur.com/UuBHZci.png
04:32	mischov	With cond, is there a way to use the value the test returns in the associated expression?
04:34	oskarkv	mischov with condp there is
07:55	wink	hmm, interop question. IllegalArgumentException No matching field found: xx for class xy
07:55	wink	but reflection clearly shows the method is there. calling it with (.. obj xx) or (.xx obj) makes no difference. ideas?
07:56	rweir	is it private
07:56	wink	not according to reflection and docs
07:56	Bronsa	wink: do you have a concrete example?
07:59	wink	http://hastebin.com/edeluzatad.clj
07:59	wink	note that I don't see an error in line 5 (in doto), only when I call it outside
08:00	wink	and apparently you need an animated gif as the input, e.g. http://asset-8.soup.io/asset/7750/5369_87a9.gif
08:00	Bronsa	wink: in the doto you're calling it as a method, passing true as an arg
08:01	wink	doh.
08:01	wink	thanks
08:01	Bronsa	np
08:01	wink	.getNumImages x true works
08:02	wink	silly error message though
08:02	Bronsa	not really, it tells exactly what's going wrong
08:02	Bronsa	you're trying to access a getNumImages field, it doesn't exist
08:02	wink	as from calling you can't differentiate between a method without args and a field
08:03	Bronsa	wink: (.-field obj) is the new syntax that should be prefered for field access
08:03	wink	plus, who uses public fields? :)
08:03	wink	oh?
08:03	Bronsa	(.field obj) is old syntax
08:04	hyPiRion	you can also do (. obj (method)) for method calls
08:04	Bronsa	or (.method obj ())
08:04	Bronsa	uh, no.
08:04	Bronsa	nevermind.
08:04	hyPiRion	yeah, that would send () as second argument
08:05	Bronsa	yeah I derped
08:05	Bronsa	wink: .- was introduced in 1.4 IIRC
10:31	timothyw	Is there a lein plugin for test.check? It would be nice to auto-run my tests as they’re developed.
10:31	ChouLin	hello, guys. I've post my question on Stackoverflow, how to get trie's leave count. I like the style of second & third answer, but they return slightly bias result. Can anyone modify this ? http://stackoverflow.com/questions/25221646/clojure-a-tail-recursion-to-get-leave-counts-of-a-trie
10:32	reiddraper	timothyw: I'm now aware of one at the moment, would be great to have one though
10:32	ChouLin	a trie out of["aat" "abt" "aac" "a" "b"] has 4 terminals, the code return 2.
10:33	ChouLin	5, typo.
10:33	timothyw	reiddraper, too right… I’m about to write a lein plugin, and was wondering about the semantics
10:34	timothyw	ie , pass in the ns and number of time to run each test?
10:34	reiddraper	timothyw: awesome. Let me know if you get something published and I'll happily add it to the test.check readme
10:35	timothyw	ok, will do
10:38	mi6x3m	hey clojure, is deinit! a suitable name for a function returned by a function constructing a graphical component and perfoming some deinitialization?
10:39	sh10151	What is deinitialization?
10:39	mi6x3m	sh10151: stopping a webserver for instance
10:41	sh10151	wouldn't that just be 'stop' then?
10:42	mi6x3m	sh10151: this was just an example
10:42	sh10151	hmm what are some other examples, trying to figure out the context
10:42	mi6x3m	sh10151: stopping a server, returning back resources, writing some log files etc.
10:43	mi6x3m	it's a general framework with examples of a component suite
10:43	sh10151	That seems really really generic -- I don't usually think of "deinitialization" when writing a log file
10:43	sh10151	Also it doesn't seem to be restricted to the opposite of whatever "initialization" is?
10:44	mi6x3m	well it's _mostly_ the opposite, but not always yes :)
10:44	mi6x3m	perhaps "cleanup"
10:44	sh10151	I think enter/exit are a little more commonly used names for that level of genericity
10:45	sh10151	see monitor-enter/monitor-exit or python's context manager __enter__/__exit__
10:45	justin_smith	mi6x3m: the rule in the jvm is usually that deinitialization is implicit when a resource leaves scope
10:45	hugod	timothyw: I haven't used, but https://github.com/runoshun/lein-watch looks like it might help you
10:45	mi6x3m	justin_smith: this is a completely different affair for the component is living for far longer than the scope
10:46	justin_smith	mi6x3m: under the jvm, that isn't possible - there is some scope where it is reachable
10:47	justin_smith	unless you expect it to randomly be released / reclaimed
10:47	mi6x3m	justin_smith: wait, I am speaking about a swing component
10:48	justin_smith	OK. finalize?
10:48	justin_smith	or just cleanup
10:49	mi6x3m	finalize might be ok yeah
10:50	mi6x3m	justin_smith: cleanup! in that case i guess?
10:51	sh10151	I don't like the ! - isn't that for things that are known to be unsafe in STM?
10:52	sh10151	writing a log file isn't
10:52	justin_smith	sh10151: well I would guess you wouldn't want to retry a cleanup!
10:53	mi6x3m	there will be no retrying here anyway
10:53	justin_smith	goddamn clojure putting punctuation in names making me sound like a middle school student
10:53	timothyw	hugod, yes that does look good. I’m gonna try it out, thanks.
10:53	sh10151	justin_smith: that would depend on the exact nature of the cleanup I think
10:54	sh10151	justin_smith: this whole affair seems quite astronautical to me
10:54	sh10151	:)
10:54	mi6x3m	is there a shortcut for calling a function only if it's not nil?
10:54	mi6x3m	alternative to when-let
10:54	Bronsa	justin_smith: next time write `cleanup!` and you'll be fine
10:54	timothyw	weavejester also created https://github.com/weavejester/lein-auto
10:54	justin_smith	mi6x3m: fnil maybe?
10:54	justin_smith	(inc Bronsa)
10:54	lazybot	⇒ 38
10:56	justin_smith	mi6x3m: wait, no, not fnil - ((or f (constantly nil)) arg1 arg2 ... argN) would work, but is not a shortcut
10:56	mi6x3m	justin_smith: yeah not really shorter and way more unreadable :)
10:56	mi6x3m	thanks for all the advice though :)
10:56	mi6x3m	(inc justin_smith)
10:56	lazybot	⇒ 59
10:58	justin_smith	mi6x3m: I often have (def nothing (constantly nil))
10:58	justin_smith	((or f nothing) args)
10:59	justin_smith	and you don't need when-let - you could also use when (when f (f args))
11:16	timothyw	when I try to use `lein release` in one of my projects, I get this error: http://pastebin.com/TrHLJ46D
11:16	timothyw	what am I missing?
11:19	justin_smith	timothyw: is lein in the path that lein inherits? it seems odd that it wouldn't be, but that is what the message seems to indicate
11:19	rweir	clojure 1.3?
11:20	timothyw	@justin_smith: yes, that’s what I thought too - but `lein` is definitely available from anywhere
11:21	timothyw	@rweir, my project’s clojure version is [org.clojure/clojure "1.5.1"]
11:36	justin_smith	timothyw: you should turn on pedentic dependency resolution in your project.clj, because something is giving you the wrong clojure version
11:36	justin_smith	:pedantic? :abort
11:36	timothyw	Somehow, when lein does `java.lang.UNIXProcess.forkAndExec`, some library or execution path with `lein` is not available.
11:37	timothyw	ok, lemme try that
11:37	justin_smith	also, be sure that lein is not only in your path, but also in your exported path
11:38	timothyw	@justin_smith, I put the `:pedantic? :abort` k/v in my project.clj. But the same error occurs
11:38	justin_smith	so not only PATH=... in your shell config, but export PATH=...
11:38	justin_smith	hmm
11:38	timothyw	ok, one sec…
11:40	timothyw	yep, in .bash_profile, I have “export PATH="$PATH:~/bin/:…”
11:40	timothyw	lein is in “~/bin/lein”
11:50	justin_smith	OK, lein-release uses clojure 1.3
12:07	timothyw	@justin_smitth, hmm, that’s interesting
12:07	timothyw	I can get around this issue by running `lein jar` and `lein pom`, manually.
12:08	timothyw	and logged a bug here: https://github.com/relaynetwork/lein-release/issues/20
12:12	justin_smith	reading the source, it is weird that they are shelling out to lein again, rather than just calling the lein-jar and lein-pom functions
12:16	llasram	The 2.4 Leiningen release series includes a built-in `release` task. Is it possible you could simply use that instead of the `lein-release` plugin?
12:29	timothyw	@justin_smith, yeah, I thought was weird too
12:33	timothyw	@llasram, I see that, yes. I’ll give that a shot. Thanks :)
12:33	llasram	timothyw: BTW, the convention on IRC to refer to someone is to just use their bare handle. No need for the `@` prefix
12:34	timothyw	cool beans - habits from other IM tools get mixed into here too :)
13:57	gfredericks	~@
13:57	clojurebot	@ is splicing unquote
13:57	gfredericks	huh.
13:57	gfredericks	~~@
13:57	clojurebot	Titim gan éirí ort.
13:57	JohnTalent	global state is managed with assoc, dissoc?
13:57	gfredericks	clojurebot: ~@ is splicing unquote
13:57	clojurebot	c'est bon!
13:57	gfredericks	~~@
13:57	clojurebot	~@ is different from ~ and different from @
13:58	gfredericks	~~@
13:58	clojurebot	~@ is splicing unquote
13:58	gfredericks	clojurebot: forget @ is splicing unquote
13:58	clojurebot	Ok.
13:58	gfredericks	JohnTalent: assoc and dissoc operate on immutable maps
13:58	gfredericks	~@
13:58	gfredericks	clojurebot: @?
13:58	rweir	JohnTalent, you may be thinking of vars
13:59	gfredericks	global state is usually avoidable
13:59	JohnTalent	rweir: i am a total newb.
14:00	rweir	JohnTalent, what specifically do you want to do?
14:01	andyf	JohnTalent: If an application has global state, immutable maps are often a convenient data structure to use for storing that global state, because of their flexible nature of adding and removing arbitrary keys.
14:02	andyf	Regardless of whether a map or some other data structure is used for holding the desired state, it is often 'pointed at' by an atom, and what that atom 'points at' can be changed over time, e.g. to new updated maps.
14:03	JohnTalent	rweir: pass around global state.
14:03	rweir	JohnTalent, that's not specific
14:03	JohnTalent	rweir: yes, because it's a nonissue until i start writing.
14:04	JohnTalent	andyf: thanks
14:05	gfredericks	sounds like he might be using an alternate sense of "global state"
14:05	rweir	indeed
14:05	gfredericks	i.e., the purely-functional variant of it
14:05	gfredericks	the state monad essentially :)
14:06	andyf	Sometimes you just gotta try out various things for yourself to learn their advantages and disadvantages.
14:12	JohnTalent	andyf: right
14:45	meoblast001	suppose i define an (fn [] .. ) and i want to call it. do i need to do (apply (fn [] ... ) [ ... ]), or is there a more natural type of syntax?
14:47	gfredericks	((fn [] ...))
14:48	gfredericks	,((fn [] 42))
14:48	clojurebot	42
14:48	meoblast001	ah, thanks
14:48	gfredericks	,(((fn [] (fn [] 42))))
14:48	clojurebot	42
14:48	gfredericks	,((((fn [] (fn [] (fn [] 42))))))
14:48	clojurebot	42
14:48	meoblast001	i feel like i'm going about this problem the wrong way...
14:49	gfredericks	,(((((fn [] (fn [] (fn [] (fn [] 42))))))))
14:49	clojurebot	42
14:49	meoblast001	i basically have times listed in a bunch of hashmaps.. and i'm trying to divide this collection of hashmaps into multiple collections if they fall into time intervals
14:50	meoblast001	i thought i'd solve this with recursion and filter... but i'm not sure if that'll be clean
14:51	gfredericks	,(doc partition-by)
14:51	clojurebot	"([f] [f coll]); Applies f to each value in coll, splitting it each time f returns a new value. Returns a lazy seq of partitions. Returns a stateful transducer when no collection is provided."
14:51	meoblast001	omg thanks i love you, gfredericks
14:52	meoblast001	there's only one problem.. i need to say "the end of this partition is anything that is no larger than the beginning of this partition"
14:52	technomancy	,(doc partition-all)
14:52	clojurebot	"([n] [n coll] [n step coll]); Returns a lazy sequence of lists like partition, but may include partitions with fewer than n items at the end. Returns a stateful transducer when no collection is provided."
14:53	technomancy	partition-by is usually the wrong thing
14:53	meoblast001	well partition-all would work great if i was saying "I want X amount of things in each collection"
14:53	meoblast001	but my problem is "I want however many things fit into a 30 second time period in one collection, then start the next collection repeating this process"
14:53	gfredericks	meoblast001: that rule seems to say that each partition has the same timestamp?
14:53	gfredericks	oooh
14:54	gfredericks	so it's based on some property of the whole partition together?
14:54	gfredericks	sort of like starting with a bunch of numbers and splitting them into chunks that sum as high as possible without exceeding X?
14:54	meoblast001	yeah. it's based on the first entry in the partition
14:55	meoblast001	so basically if the first item in a partition caries the timestamp "40", i don't want the last one to exceed "70"
14:55	meoblast001	once it does, start the next part
14:55	gfredericks	gotcha
14:55	gfredericks	reduce can do that
14:56	meoblast001	yeah.. if i throw in a collection i could probably get that.... hm
14:56	meoblast001	if i throw in a [[]], and always add each item to the last collection within this collection.... then always compare with the first item without the last collection
14:57	justin_smith	reduce can do it, you would want some kind of simulated annealing to optimize it though
14:57	meoblast001	i feel like there's a really good recursive solution to this but can't think of it right now
14:57	justin_smith	or maybe not...
15:01	gfredericks	I've got a reduce
15:01	gfredericks	one sec
15:01	meoblast001	ah. i came up with a good recursive solution on the toilet!
15:01	gfredericks	https://www.refheap.com/89089
15:01	meoblast001	i just need something like a take-until... not like reduce where it just skips an entry if it fails a condition, but one where it finishes iteration when it fails a condition
15:01	meoblast001	hmm
15:03	justin_smith	why would reduce skip anything?
15:03	gfredericks	,(defn sorta-reduce "like reduce but skips things sometimes" ...)
15:03	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: Parameter declaration ... should be a vector>
15:03	meoblast001	oh sorry. i was thinking filter, not reduce
15:03	meoblast001	had reduce on my mind for some reason
15:04	justin_smith	gfredericks: flaky-reduce
15:04	gfredericks	(inc flaky-reduce)
15:04	lazybot	⇒ 1
15:04	gfredericks	meoblast001: because I just used it ;-)
15:04	meoblast001	yup
15:04	meoblast001	reading yours right now
15:04	rpaulo	(inc flaky-reduce)
15:04	lazybot	⇒ 2
15:05	gfredericks	meoblast001: a slight modification to my function could make it take an arbitrary predicate for a candidate group, and you should be able to use that to get the specific logic you want
15:05	rpaulo	for a language that stresses imutability, this seems odd!
15:06	gfredericks	rpaulo: what's not immutable about this?
15:06	meoblast001	gfredericks: yup, thanks :)
15:06	justin_smith	rpaulo: (inc ...) in this channel is just a pseudo-syntax
15:06	justin_smith	that is not how inc really works, of course
15:06	meoblast001	i'm just making sure i understand it before doing that
15:06	gfredericks	oooh that
15:06	rpaulo	yeah, it was a joke...
15:07	justin_smith	OK, you forgot to attach the joke metadata, which led to a reader error on my end
15:07	rpaulo	:)
15:07	meoblast001	gfredericks: this solution is clever
15:08	meoblast001	i don't do as much clojure as i wish to, so my solutions are never this clever ;)
15:08	meoblast001	or.. rarely
15:10	gfredericks	aw man clojure 1.7 doesn't have update yet
15:10	meoblast001	peek is an interesting function
15:14	justin_smith	my minor reworking of gfredericks' version https://www.refheap.com/89091
15:16	meoblast001	style question. if i'm doing a really complex expression inside of the [] of a let, how far in should i indent?
15:16	justin_smith	meoblast001: exactly as far as emacs auto-indents
15:16	meoblast001	lol. i'm not using emacs
15:16	meoblast001	inb4 "that's your problem"
15:16	justin_smith	heh
15:17	wcauchois	hey, i'm trying to use netty in clojure and i'm getting a pretty weird exception: Cannot cast io.netty.handler.codec.http.HttpServerCodec to [Lio.netty.channel.ChannelHandler
15:17	wcauchois	HttpServerCodec is definitely an instance of ChannelHandler so i don't understand that
15:17	meoblast001	justin_smith: how far does your emacs do it?
15:17	justin_smith	meoblast001: a multi-line binding in let should be indented exactly as much (relatively) as it would be anywhere else
15:17	wcauchois	anyone know what that [L is in front of the type? could that have anything to do with it?
15:17	justin_smith	wcauchois: are you trying to use a varargs method?
15:17	meoblast001	so one indent forward from the (let ?
15:18	wcauchois	justin_smith: yes, i am
15:18	justin_smith	wcauchois: varargs methods are just a java syntactic sugar, we don't have an equivalent in clojure
15:18	justin_smith	wcauchois: you need to put all the optional arguments into an array
15:19	wcauchois	do i still pass the non-optional arguments regularly, or do i pass the whole thing as an array?
15:19	justin_smith	(method required-arg (into-array [optional1 optional2 optional3]))
15:19	gfredericks	justin_smith: I see your minor reworking and raise you a genericification: https://www.refheap.com/89092
15:19	gfredericks	meoblast001: ^
15:19	justin_smith	the javadoc should make clear which are required and which are optional
15:19	wcauchois	ok let me try that
15:19	wcauchois	the function is also overloaded, although i'm calling the 2-arg version which isn't (there are two 3-arg ones)
15:19	meoblast001	woo
15:20	wcauchois	would clojure dispatch based on the types to the overloaded ones?
15:20	justin_smith	wcauchois: concrete example I answered recently on so http://stackoverflow.com/questions/25145550/how-to-instantiate-path-object-using-clojure/25145835?noredirect=1#comment39155787_25145835
15:21	justin_smith	wcauchois: notice in that case, java.nio.file.Paths/get needs a single string arg (in order to do the dispatch properly), and then all other args needed to be in an array
15:21	justin_smith	wcauchois: in this kind of case it's not really clojure dispatching, it's the jvm dispatching - you need to provide the right classes in the clojure invocation so that the jvm knows which method to dispatch to
15:22	wcauchois	which you can do with ^Type, correct?
15:22	wcauchois	also now i'm getting no matching method found. i passed (into-array Object []) as the last argument (again, i'm calling the 2-arg version and there are other 3-arg overloads)
15:23	justin_smith	wcauchois: well ^Type helps resolution at runtime, but the real issue is that you need the right signature for the method call to resolve (which is why all the args above were strings, but one had to be outside the array)
15:23	justin_smith	the varargs should be preceded by at least one non-array argument I think, almost always
15:24	justin_smith	wcauchois: do you have a link to the javadoc for the method in question?
15:24	justin_smith	gfredericks: very nice
15:24	justin_smith	(inc gfredericks)
15:24	lazybot	⇒ 81
15:25	oskarkv	meoblast001 gfredericks what about this? https://www.refheap.com/89093
15:25	wcauchois	okay, i think it worked by passing the first required arg regularly and then passing the second arg as a singleton array
15:25	wcauchois	yess no more exceptions. still not working, but now i'm on to the next bug :)
15:25	justin_smith	wcauchois: yeah, I think that is pretty much always how it needs to be done
15:25	wcauchois	ok. thanks for the help!
15:25	gfredericks	that's the first time in half a year I've gotten karma for something that wasn't a joke
15:25	justin_smith	wcauchois: do you have a specific reason to use netty directly instead of using ring?
15:26	gfredericks	oskarkv: hey cool
15:26	gfredericks	seems better for being lazy
15:26	gfredericks	or at least it would be lazy if you had wrapped it in lazy-seq :)
15:26	oskarkv	yeah :P
15:28	wcauchois	justin_smith: errr i was planning on writing my own adapter. i want to use websockets as well. i found a ring netty adapter but it didn't look like it supported websockets.
15:29	justin_smith	wcauchois: oh, nice
15:29	wcauchois	there's aleph, which looks really nice, but it's not ring-compatible
15:29	wcauchois	also i thought maybe this would be a good learning experience? haha
15:30	wcauchois	tho it seems more like i'm learning about the warts of java interop than actual clojure
15:30	wcauchois	oh wait
15:30	wcauchois	aleph is ring-compatible, what am i saying
15:30	wcauchois	anyway, learning experience etc
15:31	justin_smith	java interop is not so bad once you get used to it, the rules are few in number and very consistent - and aleph is much more than a netty adapter
15:32	justin_smith	the trick is realizing which parts of java are really fictions of the compiler (like generics and varargs) so that you can provide the version without said fiction (which clojure will not support)
16:01	gfredericks	challenge: given a number, try to express it in clojure/java by referencing only the Math class
16:03	SagiCZ11	,Math/PI
16:03	clojurebot	3.141592653589793
16:09	milos_cohagen	am i using the term 'yak shaving' correctly if i used it to describe the last two hours of emacs/pkg/cider woes?
16:10	gfredericks	probably depends on how valuable those woes were
16:10	justin_smith	probably
16:11	justin_smith	for the convenience of anyone considering gfredericks' challenge https://www.refheap.com/89095
16:11	gfredericks	I was just assembling a similar list
16:11	justin_smith	tab-complete plus refheap-paste-region :)
16:12	gfredericks	ha
16:14	SagiCZ11	i guess i dont understand the challenge
16:14	justin_smith	SagiCZ11: make an arbitrary number, using only functions and constants in java.lang.Math
16:14	gfredericks	e.g., you can express 23 as ##(Math/floor (Math/exp Math/PI))
16:14	lazybot	⇒ 23.0
16:15	justin_smith	here's an idea: have a bot generate a random integer between 0 and 1000, first person to make an == number using java.lang.Math wins?
16:16	SagiCZ11	ok but what number should we make?
16:16	gfredericks	&(rand-int 1000)
16:16	lazybot	⇒ 860
16:16	gfredericks	that one
16:16	justin_smith	OK
16:17	gfredericks	you gotta generate a long, not a double
16:17	justin_smith	oh, so == is not good enough?
16:17	gfredericks	ah I see what you did there
16:18	gfredericks	,(Math/round 42.0)
16:18	clojurebot	42
16:18	justin_smith	ok, that's trivial anyway (which is why I suggested just using == rules, but whatever, no biggie)
16:18	gfredericks	yeah
16:18	gfredericks	I guess I don't care :)
16:30	gfredericks	,(Math/toDegrees (Math/exp (Math/abs Math/E)))
16:30	clojurebot	868.2752680712246
16:30	gfredericks	I guess the abs there is redundant :)
16:31	justin_smith	yeah, toDegrees is a godsend here in general
16:31	justin_smith	still, this is very hard
16:31	gfredericks	I would be further along if this baby hadn't woken up
16:31	SagiCZ11	i think one could write a script in clojure that goes through the possible functions.. just brute force
16:33	justin_smith	question is, can you write that program faster than one of us can find the solution by hand?
16:33	gfredericks	I was going the programmatic route
16:34	justin_smith	given the existence of addExact, if you have enough space for the code, you can trivially make any number programatically
16:34	justin_smith	but it would be very ugly for most numbers
16:35	SagiCZ11	i just thought it would be a cool exercise for a beginner like me :)
16:35	gfredericks	addExact?
16:41	meoblast001	when i use a java.lang.Long in a methematical operation, why do i get output like "1307/15" when i print it?
16:42	justin_smith	meoblast001: that's a rational - you can coerce it to a double or long if you prefer some other printing format
16:42	justin_smith	,(Math/subtractExact (Math/addExact (Math/subtractExact (Math/round (Math/toDegrees (Math/exp Math/E))) (Math/round (Math/pow (Math/floor Math/PI) (Math/floor Math/E)))) (Math/round (Math/floor Math/E))) (Math/round (Math/floor (Math/getExponent Math/PI))))
16:42	clojurebot	#<CompilerException java.lang.IllegalArgumentException: No matching method: subtractExact, compiling:(NO_SOURCE_PATH:0:0)>
16:42	justin_smith	ergh
16:42	justin_smith	works locally
16:43	meoblast001	ah, okay
16:43	meoblast001	i read you can just put a (double ...) around it, and that should work
16:43	justin_smith	yeah, the rational form carries for precision, but is slightly slower for calculations
16:44	justin_smith	you can wrap it in (double ...) or (long ...) or feed it to format if you need to print it differently
16:44	justin_smith	*carries more precision
16:50	nbeloglazov	https://github.com/bbatsov/clojure-style-guide#two-spaces What is the difference between first and second bullets? When should one align using 2 spaces?
16:51	justin_smith	nbeloglazov: when is not a function
16:52	nbeloglazov	So macros and so on?
16:52	justin_smith	defn/when/let/fn/for etc. should get two space indent, regular functions should get extra arguments lined up with the first
16:52	justin_smith	it's a special form actually
16:52	justin_smith	even macros should generally get aligned with the first function (unless they are things like fn that wrap a special form)
16:53	nbeloglazov	I would say wording is confusing then
16:53	justin_smith	*aligned with the first arg
16:53	gfredericks	justin_smith: ooh these arithmetic functions are java 7
16:53	gfredericks	java 8 I mean
16:53	gfredericks	I hereby forbid java 8 from the competition
16:53	justin_smith	gfredericks: ahh, figures
16:53	justin_smith	lol
16:53	justin_smith	give me the java 7 list then
16:53	gfredericks	$google java 7 math
16:53	lazybot	[Math (Java Platform SE 7 ) - Oracle Documentation] http://docs.oracle.com/javase/7/docs/api/java/lang/Math.html
16:53	justin_smith	I did get the correct answer with java 8 though
16:55	gfredericks	I just got 859
16:55	gfredericks	wait
16:56	gfredericks	&(Math/ceil (Math/toDegrees (Math/ceil (Math/expm1 Math/E))))
16:56	lazybot	⇒ 860.0
16:56	gfredericks	kaboom
16:56	justin_smith	damn
16:56	justin_smith	nice
16:58	gfredericks	&(rand-int 10000) ; next target
16:58	lazybot	⇒ 9578
17:01	hyPiRion	make swearjure golfing gogo
17:01	hyPiRion	/s/make//
17:02	gfredericks	technically you can get to any double by applying nextUp enough times :)
17:03	justin_smith	gfredericks: even faster if you combine nextUp and ceil
17:03	gfredericks	wooooah
17:04	gfredericks	I don't know how to get to -infinity to start with though
17:04	catern	haha
17:04	catern	that is fun
17:04	catern	justin_smith: p. nice idea
17:04	justin_smith	,(Math/ceil (Math/nextUp (Math/ceil (Math/nextUp (Math/ceil Math/PI)))))
17:04	clojurebot	6.0
17:04	justin_smith	ad nausium
17:05	gfredericks	let's call this game "java math" just to be infuriatingly generic
17:05	justin_smith	heh
17:05	catern	how come you have to do it only with java math, though? why not arbitrary clojure?
17:05	justin_smith	with that, plus pow / log you get pretty close to a generic formula
17:05	gfredericks	I think it'd be fun to work out a function that can find an expression for an arbitrary double quickly
17:06	hyPiRion	gfredericks: that'd be boring though
17:06	gfredericks	justin_smith: hey good point
17:06	justin_smith	gfredericks: I am sure you can do it with nextUp / ceil / pow / log
17:06	hyPiRion	,(map (fn [x] (.toString x)) [2.0 3.0 4.0 5.0 6.0])
17:06	clojurebot	("2.0" "3.0" "4.0" "5.0" "6.0")
17:06	gfredericks	hyPiRion: huh?
17:07	catern	hyPiRion: that's numberwang!
17:07	hyPiRion	gfredericks: oh, I forgot some doubles cannot be printed nevermind
17:07	gfredericks	what does printing have to do with it anyhow?
17:07	catern	gfredericks: how about calling it javawang
17:08	hyPiRion	gfredericks: find an expression for an arbitrary double?
17:08	gfredericks	hyPiRion: oh the rules of java math say you can only use the Math class
17:08	hyPiRion	oh
17:08	gfredericks	and you cannot use java 8
17:08	gfredericks	or 9 or 10
17:08	hyPiRion	gfredericks: can I fork java and add constants for every double?
17:09	gfredericks	you cannot use Java vhyPirion either
17:09	justin_smith	hyPiRion: just give it a version number smaller than 8
17:09	gfredericks	you have to use java 7
17:11	JohnTalent	anyone want to develop a game with me? action/adventure using clojure, 2d canvas. i can do the art and scripting.
17:17	gfredericks	justin_smith: should we say it has to fit in a tweet? :)
17:17	gfredericks	that should rule out a lot of trivial solutions
17:30	JohnTalent	how do i change my 1.5.1 to 1.6.0?
17:30	JohnTalent	why is this rocket science?
17:30	gfredericks	JohnTalent: are you using leiningen?
17:33	JohnTalent	gfredericks: now not, but it's also a problem in leiningen.
17:34	gfredericks	in leiningen you can change the entry in your project.clj
17:34	JohnTalent	i did that
17:35	gfredericks	is this with respect to a plugin?
17:35	JohnTalent	i'm trying to follow http://astashov.github.io/blog/2014/07/30/perfect-clojurescript-development-environment-with-vim/
17:36	JohnTalent	i changed 1.5.1 to 1.6.0 in th project file
17:36	gfredericks	and what's the evidence that it doesn't work?
17:38	JohnTalent	hold on
17:38	JohnTalent	how do i find out which clojurescript that i have?
17:39	justin_smith	lein deps :tree will show all your dependency versions
17:39	justin_smith	there is another command to show all your plugin versions iirc
17:43	meoblast001	damn do i have a lot of problems today
17:43	meoblast001	https://gist.github.com/meoblast001/dd0b2d34afd3928381f7
17:43	meoblast001	i'm getting messages here about this not being tail recursion. is there a way i could fix this?
17:44	gfredericks	it's not a tail recursive algorithm so you can't use recur
17:44	amalloy	meoblast001: it looks like you are trying to solve a problem that is better solved by ##(partition 2 1 '(a b c d))
17:44	lazybot	⇒ ((a b) (b c) (c d))
17:44	gfredericks	meoblast001: you're trying to produce something for each pair in the sequence?
17:45	gfredericks	what amalloy said
17:45	JohnTalent	i just 'lein cljsbuild auto dev'. how can I tell it compiled 1.6.0 and not 1.5.1?
17:45	meoblast001	hmm. you're right
17:45	gfredericks	~recursion
17:45	clojurebot	It's greek to me.
17:45	amalloy	me too, clojurebot. me too
17:45	meoblast001	all of this haskell i'm learning is warping the way i code
17:45	meoblast001	i'll switch to using partition
17:45	amalloy	uhhhhh, pretty sure haskellers would zipWith f xs (tail xs)
17:48	JohnTalent	ugh, python isn't serving up a sample page.
17:51	justin_smith	meoblast001: in general, you can convert a non-tail recursion to a tail recursion by adding an accumulator argument (and sometimes this also means a reduction as your last step)
17:51	justin_smith	this turns the stack building of non-tail recursion into a heap-building tail recursion
17:53	meoblast001	oooh
17:53	meoblast001	i'll look that up in more detail momentarily
17:58	michaelr	sorting a collection which om is rendering seems to mess everything up
17:58	michaelr	anyone familiar with this issue and workarounds?
17:58	dnolen_	michaelr: you need to supply keys for everything
17:58	dnolen_	don't sort the app state either
17:58	dnolen_	just sort at the presentation layer
18:00	SagiCZ11	,(for [i [:a :b] j [1 2]] (list i j))
18:00	clojurebot	((:a 1) (:a 2) (:b 1) (:b 2))
18:00	michaelr	dnolen_: I have keys.. I'll to move the sorting to the rendering part
18:00	SagiCZ11	what if i want to iterate both colls in parallel?
18:00	michaelr	thanks
18:00	SagiCZ11	and get ((:a 1) (:b 2))
18:01	metellus	,(map list [:a :b] [1 2])
18:01	clojurebot	((:a 1) (:b 2))
18:01	SagiCZ11	metellus: thanks
18:03	michaelr	dnolen_: works ;)
18:10	SagiCZ11	,(map inc (take 3 (drop 2 [2 5 4 1 3 6])))
18:10	clojurebot	(5 2 4)
18:12	SagiCZ11	,(contains? :a {:a nil :b 2})
18:12	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: contains? not supported on type: clojure.lang.Keyword>
18:12	SagiCZ11	,(contains? {:a nil :b 2} :a)
18:12	clojurebot	true
18:13	justin_smith	SagiCZ11: just don't expect it to work on anything sequential (at least not the way you would expect)
18:13	SagiCZ11	(def m {:a nil :b 2})
18:13	SagiCZ11	,(and (contains? m :a) (nil? m :a))
18:13	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: m in this context, compiling:(NO_SOURCE_PATH:0:0)>
18:14	SagiCZ11	(do
18:14	SagiCZ11	(def m {:a nil :b 2})
18:14	SagiCZ11	(and (contains? m :a) (nil? m :a)))
18:14	SagiCZ11	darn it
18:14	justin_smith	SagiCZ11: that call to nil? is wrong
18:15	SagiCZ11	true
18:15	SagiCZ11	,(let [m {:a nil :b 2}]
18:15	SagiCZ11	(and (contains? m :a) (nil? (m :a))))
18:15	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading>
18:15	justin_smith	,(let [m {:a nil}] (and (contains? m :a) (nil? (m :a))))
18:15	clojurebot	true
18:15	SagiCZ11	whats wrong with my version?
18:16	justin_smith	multiple lines
18:16	johnwalker	why is the use of :pre and :post idiomatic compared to assert ?
18:16	SagiCZ11	justin_smith: thanks
18:17	johnwalker	there doesn't appear to be a way to add messages to them
18:18	gfredericks	johnwalker: there's a clojure-dev post about that recently; I agree it's a big drawback
18:18	johnwalker	ahh, thats good to hear
18:33	lpvb	what happens if I put an (int-array) into an atom and mutate the array?
18:34	JohnTalent	Caused by: java.lang.NullPointerException: core.clj:49 cljs.core/import-macros[fn]
18:35	jeremyheiler	lpvb: try it out in a repl
18:35	justin_smith	lpvb: you get an atom with a mutated array in it, I think ##(let [a (int-array 3 0) t (atom a)] (aset a 1 42) (into [] @t))
18:35	lazybot	⇒ [0 42 0]
18:37	JohnTalent	goddamned bugs. it's looking for clj when i want cljs
19:47	scheafer	hi folks. anybody familiar with cgrand's spreadmap library?
19:48	scheafer	i'm trying to read a named sheets from a workbook. i can't find the proper incantation
19:52	supersym	scheafer: (.getName wb ref) ?
19:54	scheafer	supersym: IllegalArgumentException No matching method found: getName for class net.cgrand.spreadmap.SpreadSheet
19:54	supersym	EvaluationWorkbook
19:55	supersym	would be the type to do it on I guess
19:55	supersym	https://github.com/cgrand/spreadmap/blob/master/src/net/cgrand/spreadmap.clj
19:55	supersym	im not too familiar with the whole reify deal but its a concrete implementation of abstract concept from what I learned sometime ago
19:56	supersym	but the source shall show you the way and perhaps a little tinkering that is :)
19:56	scheafer	thanks :) i've scanned the source but couldn't find a quick way to construct an evaluation workbook
19:57	supersym	well personally what I can make up from it this might not be intented to do so
19:57	supersym	e.g. your supposed to end up with the final form and workbook is afteral private
19:58	supersym	I do take it you feed it 2 params?
19:59	supersym	ok I see now
20:00	supersym	SpreadSheet is the final type indeed, getter and also workbook are application internal use only and so not a public API for yoy
20:00	scheafer	i think i'll open an issue... thx!
20:10	supersym	yeah... the french software isnt very familiar for its user-friendliness nor documenting in human readable format what stuff does :P
20:12	supersym	Im just running it in my own windows lighttable environment now to see how you are supposed to pull that data out of teh main objects
20:12	supersym	(sheet-index spreadmap Valueable SheetMisc ->SpreadSheet value formula-tokens CellMisc fm=) are publics anyway so those should be able to do it, or it isn't possible
20:15	blur3d	justin_smith: I pushed the arduino dashboard project I’ve been working on to github. https://github.com/blakejakopovic/testdrive
20:33	justin_smith	blur3d: cool
20:34	blur3d	justin_smith: It’s still just clojuresript->javascript, but I’m working on a few things that will help it move to node based
20:36	blur3d	the fimata library will be converted to cljx, so it will support clojurescript, and it is getting support for different types of adapters (serial/tcp.. both java based and nodejs)
20:36	blur3d	the Arduino Firmata library is getting a few required patches, and also adding support for the Spark Core device
20:37	blur3d	I’ve also ordered a Beaglebone.. so I can play with that also
20:37	justin_smith	very nice, yeah
20:38	justin_smith	with beagle bone the sensors and the web server could all be on the same board
20:38	blur3d	Basically, I hope to keep the dashboard fairly generic.. so it will just be a dumb terminal.. and as long as you send it messages with the right format, it should work fine
20:38	blur3d	https://github.com/blakejakopovic/TestDrive/blob/master/src/cljs/testdrive/core.cljs#L255
20:39	blur3d	yeah, that would be very nice.
21:54	prachetasp	hi does anyone know how to use a keyword that has parentheses in it
21:55	prachetasp	i am using jdbc to get the last inserted record and I get back {:last_insert_id() 1111}
21:56	prachetasp	I'm planning on just destructuring it but it made me curious whether it was possible to have parentheses in a keyword
21:58	justin_smith	,(keyword "foo()")
21:58	clojurebot	:foo()
21:58	justin_smith	yup
21:58	prachetasp	@justin_smith thanks!
21:59	prachetasp	duh... smh
21:59	justin_smith	so you can't use that for destructuring, but you can do (get m (keyword "foo()"))
21:59	prachetasp	or ((keyword "foo()") m)
22:00	prachetasp	is there any reason to use get?
22:01	justin_smith	it's more explicit - if neither my keyword or my map is a literal, I like to use get
22:01	justin_smith	but that's a style preference, of course
22:02	prachetasp	makes sense
22:02	prachetasp	thanks
22:33	rhg135	not completely style preference, using get can prevent NPEs
22:36	brehaut	,(:foo {} 0)
22:36	clojurebot	0
22:36	brehaut	,({} :foo 0)
22:36	clojurebot	0
22:37	amalloy	only if there's any possibility that the thing you're looking up could be nil, rhg135. and if what you're looking up is accidentally nil, an NPE is not the worst thing that could happen
22:37	JohnTalent	what does ^{} mean?
22:37	brehaut	JohnTalent: assign the map {} as meta data to the next form read
22:38	JohnTalent	form read?
22:38	brehaut	the s-expression structures (forms) read by the reader before they are evaluated
22:39	JohnTalent	ok
22:39	JohnTalent	thanks
22:39	brehaut	,(read-string “(foo :bar 1)”)
22:39	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: “ in this context, compiling:(NO_SOURCE_PATH:0:0)>
22:39	amalloy	brehaut: the smart quotes. it's like 1998 all over again
22:39	brehaut	amalloy: yeah no idea how that happened.
22:40	amalloy	are you using microsoft word as your irc client, maybe? that could do it
22:40	brehaut	haha
22:40	brehaut	no im using colloquay which ive used for years with out that madness
22:40	brehaut	it did recently update though'
22:42	talios	people still use colloquay? :)
22:42	brehaut	no i just pretend to
22:42	brehaut	i dont want to own up to using irssi
22:43	talios	oh wait - brehaut's not people, soilent green is
22:43	talios	at least use weechat from the console man :)
22:43	brehaut	i dont need to be macho about my IRC usage
22:46	amalloy	brehaut: we should start a club: people who use irc clients designed for little kids
22:46	brehaut	amalloy: lol :)
22:47	catern	baby's first irc client
22:47	brehaut	an app that doen't actually connect, but uses markov generators to randomly abuse you and occasionally answer questions with non-sequiters
22:50	rhg135	hmm
22:51	rhg135	challange accepted
22:54	kristof	this is a bizarre conversation to walk into.
22:55	talios	not the strangest I've seen :)
22:57	johnwalker	does anyone know of a java project with insane dependencies ?
22:57	johnwalker	i'm looking to stress test leiningen
22:58	johnwalker	tjd and i ran into a stackoverflow working with particularly bad corporate java
23:00	danielcompton	I'm trying to create a java Keystore$SecretKeyEntry but I'm not sure how to access the inner class correctly
23:00	kristof	inner classes... shudder
23:01	danielcompton	I get CompilerException java.lang.ClassNotFoundException: java.security.Keystore$SecretKeyEntry, when I try
23:01	brehaut	im no java expert, but arent inner classes inner for a reason?
23:01	rhg135	nope
23:01	danielcompton	brehaut: I agree, however I think they're required to store a secret key in a java keystore. http://docs.oracle.com/javase/7/docs/api/javax/crypto/SecretKeyFactory.html#getInstance(java.lang.String)
23:02	danielcompton	brehaut: the sample code shows it doing that (correct link: http://docs.oracle.com/javase/7/docs/api/java/security/KeyStore.html)
23:03	amalloy	brehaut: inner classes aren't necessarily private
23:03	brehaut	amalloy: well that would be typically java wouldnt it
23:04	brehaut	i mean, i can understand that you might pass instances of them around
23:04	amalloy	danielcompton: is there anything specific you're having trouble with? that sample code all looks pretty standard to translate to clojure, at first glance
23:04	danielcompton	amalloy: to call it in Clojure, I did (java.security.Keystore$SecretKeyEntry. myks mysecretkey)
23:04	danielcompton	amalloy: does that look right?
23:05	amalloy	i only see one parameter for that constructor. what do you imagine the second is going?
23:06	kristof	rhg135: I love the implication of that.
23:06	amalloy	ie, http://docs.oracle.com/javase/7/docs/api/java/security/KeyStore.SecretKeyEntry.html#KeyStore.SecretKeyEntry(javax.crypto.SecretKey)
23:07	justin_smith	I see two constructors - secretkey or secretkey, attributeset
23:07	danielcompton	amalloy: I thought I needed to pass the outer class, as the outer class isn't static
23:07	justin_smith	oh, I was looking at security, not crypto, never mind
23:07	mthvedt	danielcompton: that’s only if the inner class isn’t static
23:08	danielcompton	amalloy: it doesn't work taking away myks either
23:08	mthvedt	these code examples suggest you might need to import the inner class
23:08	mthvedt	before clojure likes the constructor
23:08	amalloy	mthvedt: no
23:08	mthvedt	but that’s just a wild guess.
23:08	danielcompton	I've imported the inner class too
23:09	amalloy	danielcompton: you may have any number of other problems, but the only thing i can tell from "here is a line of code, it doesn't work" is that you definitely don't want to pass the keystore argument in
23:09	danielcompton	amalloy: I'll put together a failing example other people can run which might reveal the problem
23:19	mthvedt	danielcompton: wild guess #2, maybe your import is wrong. that can also cause classnotfound
23:27	danielcompton	amalloy: rubber duckying it in the repl seems to have fixed it. It works for me now, not sure what I had typed wrong that was causing the issues
23:28	danielcompton	Thanks