#clojure – 2015-03-04

2015-03-04

00:01	ddellacosta	justin_smith: thanks, that's the conversation I needed to have. Much appreciated
00:01	justin_smith	np
00:07	rhg135	i miss clojure so much D:
00:08	ob_	what happened?
00:08	rhg135	after writing 3000 lines of java for an app that still only half-works i feel sad
00:08	ob_	:(
00:09	ob_	rewrite in clojure, problem solved!
00:09	rhg135	android
00:09	rhg135	i guess cljs exists, but glue code
00:10	arrdem	lein-android exists..
00:10	codestorm	would be cool if android had a first class FP option
00:11	arrdem	there's a GSoC project proposed to build a Clojure -> ART compiler..
00:12	ob_	welcome your new overlords android and ios
00:12	ob_	and js
00:12	arrdem	eh compiler targets :D
00:13	Guthur	there has always been overlords they just get toppled now and then
00:18	cemerick	arrdem: do you have a link for that beyond what's @ http://dev.clojure.org/display/community/Project+Ideas
00:18	cemerick	?
00:18	arrdem	cemerick: neg.
00:20	rhg135	on the upside i atleast am using clj_ds
00:20	justin_smith	I won't ask what that is and just imagine that's a clojure that targets the nintendo ds
00:20	rhg135	but no literals make rhg135 sad
00:25	rhg135	i know i enjoy reading code so here in case anyone wants to read java: https://github.com/rhg/derpyirc
00:27	Guthur	I have a template, and i would like to run a shell command when doing lein new
00:27	Guthur	is there any best practice for that
00:28	justin_smith	if lein lets you do that, it would be a very interesting way to root people's boxes
00:28	rhg135\|zzz	it's called so mainly due to beaing a temp name, but it's quite fitting if you read the code
00:28	rhg135\|zzz	cast all the things!
00:29	johnmendonca	in the repl, how do I look up docs for something like clojure.lang.Namespace?
00:29	justin_smith	,(apropos "javadoc")
00:29	clojurebot	()
00:30	justin_smith	hrmph
00:30	Guthur	justin_smith: well the template seems to be just a function that lein calls which "renders" the files using what ever name is passed in
00:30	Guthur	so presumably one could invoke a shell command there
00:30	justin_smith	johnmendonca: clojure.repl/javadoc can do that for you
00:30	Guthur	but i was wondering if there were some other approach
00:31	justin_smith	Guthur: yes, and given that no OS is without local privelege escelation bugs, it would be a way to get root on dev boxes
00:31	Guthur	yeah, but then everyone is careful about code they run on their boxes, right
00:31	Guthur	hehe
00:31	Guthur	this is for myself so I not really worried
00:32	johnmendonca	justin_smith: thanks javadoc is working, I thought I tried it already...
00:32	justin_smith	"wget http://i-own-ur-box \| sudo sh" is always the first line of my install guide
00:33	TEttinger	justin_smith, quick give me a simple transducer example! I'm trying to show off what clojure does
00:33	johnmendonca	though when i run (javadoc clojure.lang.Namespace) it opens a google tab with two not useful result
00:33	justin_smith	johnmendonca: wow, that's weird
00:34	justin_smith	TEttinger: ##(sequence (comp (take 10) (map inc) (filter even?)) (range))
00:34	lazybot	⇒ (2 4 6 8 10)
00:34	justin_smith	not the greatest example - what's cool there isn't really visible from the syntax
00:35	TEttinger	(inc justin_smith) ; thanks, I can understand it
00:35	lazybot	⇒ 204
00:37	justin_smith	Guthur: in all seriousness, I am sure you can fit a call to clojure.java.shell/sh into your driver function. But I also feel sketched out about the fact that it would be so easy.
00:37	engblom	It seem like Gitorious has been the prefered place for Clojure code. As it will close on June 1 because Gitlab aquired Gitorious, lets hope all projects move to the same place so you do not end up searching many sites for suitable libraries and stuff.
00:38	justin_smith	engblom: what's on gitorious? I don't know of any clojure projects there.
00:39	justin_smith	engblom: most of us are using github, no? I have a paid account, I would think they would have told me if they were shutting down.
00:40	engblom	justin_smith: You are right. I must have slept too little as when I woke up this morning and saw the news about Gitorious I mixed it with Github.
00:40	justin_smith	oh, OK
00:41	justin_smith	engblom: anyone who hangs out here has seen me have sillier mixups
01:01	Niac_	what is about the side-effect-free in clojure?
01:11	numberten	is the idiomatic way to create directories in clojure just java interop?
01:11	arrdem	clojure.java.io is your friend
01:16	l3dx	how do I get clojure to call a method with one required arg + varargs instead of the overload with a single arg of a different type?
01:17	l3dx	specifically http://docs.oracle.com/javase/7/docs/api/java/nio/file/Paths.html#get(java.lang.String,%20java.lang.String...)
01:17	numberten	arrdem: thanks :)
01:17	l3dx	insetead of the one taking a URI
01:21	l3dx	I'm trying to call get(String)
01:22	cemerick	l3dx: (java.nio.file.Paths/get "foo" (into-array String []))
01:26	Eremox	Why is there no official standard on clojure? Is it to young?
01:26	l3dx	cemerick: thanks :)
01:27	arrdem	Eremox: there is no standard library or parser spec.
01:27	arrdem	we are entirely implementation defined
01:28	TEttinger	there are 3 main implementations, all of which have small platform differences in how some parts of the language work. CLJS is the most different, and even that is still pretty close to clojure
01:29	TEttinger	(inc cemerick) ; thanks, that's handy
01:29	lazybot	⇒ 18
01:30	mercwithamouth	hey is there a way for me to tell leiningen to use an older version of a template? like i'd like to use luminus...and JUST purchased a book that uses the web app that was published last month. however 2 days ago luminus updated to a new version that's completely different
03:15	dysfun	mercwithamouth: hrm, what's changed?
03:15	dysfun	hrm, they appear to have added ragtime
03:17	dysfun	hrm, they've changed a few things
03:19	mercwithamouth	dysfun: hey. lib-noir is gone
03:19	mercwithamouth	quite a few things it seems
03:21	dysfun	noir-exception is still there
03:21	dysfun	i don't use lib-noir or noir-exception in my stuff
03:21	dysfun	i have been using the luminus template to give me a base and then heavily customising it
03:21	dysfun	looks like i'm going to have to just go build my own template now
03:27	mercwithamouth	dysfun: yeah. i just bought clojure web development essentials and now it looks like i won't be able to follow it as it
03:47	dysfun	mercwithamouth: that's unfortunate. but you can check out one of my projects based on the old luminus if it helps
03:47	dysfun	let me see what i've got that i didn't touch much after generation
03:49	dysfun	oh, i've just found one that i generated randomly and didn't use
03:49	dysfun	you should be able to follow your book with that
03:53	dysfun	the state of web development in clojure is such that i keep finding cool libraries i want to integrate
03:53	dysfun	so you'll probably move on from old luminus quite naturally
05:49	devll	Hi,how to splice a lazy seq in macro?
05:50	devll	(defmacro splice-test [col]
05:50	devll	`(println ~@con))
05:50	devll	(splice-test (range 10))
05:50	devll	(splice-test (doall (range 10)))
05:50	devll	none of all working.
05:52	devll	am I being muted for asking too easy questions?
05:52	Bronsa	devll: that doesn't make sense, you're trying to use the runtime value of (range 10) at compile time
05:52	devll	oh
05:53	Bronsa	devll: what exactly is that you want to do?
05:53	devll	I wanted to do mysql batch insert
05:54	devll	(j/insert! db-spec :fruit
05:54	devll	{:name "Pomegranate" :appearance "fresh" :cost 585}
05:54	devll	{:name "Kiwifruit" :grade 93})
05:55	Bronsa	devll: can't you justs iterate over a collection with map/reduce/doseq?
05:55	devll	slow
05:55	devll	too slow
05:55	Bronsa	that's not true
05:56	Bronsa	doseq expands to a loop, it's hardly going to be too slow
05:56	devll	yes. doseq is not slow.
05:57	devll	inserting one by one is.
05:57	wagjo	devll: (apply j/insert db-spec :fruit maps)
05:57	Bronsa	gotcha, then you didn't explain yourself. use apply
05:58	devll	sorry.My English sucks.so does my programming.I am working on it.
05:58	devll	thanks.
05:59	devll	(inc wagjo)
05:59	lazybot	⇒ 4
05:59	Bronsa	no worries, try what wagjo said
05:59	wagjo	you're welcome
06:08	enaden	sp
06:11	egli	it appears that I can't call juxt on macros
06:11	egli	I would like to ((juxt .getMessage .getLineNumber) exception)
06:12	wagjo	egli: juxt works with functions, and macros are not functions
06:13	egli	wagjo: I figured as much, thanks
06:13	wagjo	egli: try -> macro
06:13	egli	I want to do (zipmap [:error :line :column] ((juxt .getMessage .getLineNumber .getColumnNumber) exception))
06:13	egli	instead of {:error (.getMessage exception)
06:13	egli	:line (.getLineNumber exception)
06:13	egli	:column (.getColumnNumber exception)}
06:14	egli	but maybe it's not worth the hassle
06:15	egli	wagjo: -> probably doesn't work in this case
06:15	wagjo	egli: yep, won't work for your case
06:15	Bronsa	egli: .getMessage & co are neither function nor macros
06:16	egli	Bronsa: ah .getMessage are macros that expand to a special form
06:16	Bronsa	they are sugar for . forms that only make sense in a call position, you can't use .foo as a higher-order method call
06:17	egli	Bronsa: ok all clear now. Thanks
06:18	wagjo	egli: maybe you can use memfn
06:20	wagjo	,((juxt (memfn isEmpty) (memfn length)) "foo bar")
06:20	clojurebot	[false 7]
06:22	egli	wagjo: ah, thanks. Just what the doctor ordered
06:22	Bronsa	wagjo: that code requires reflection. I don't think it's worth using memfn in egli's case
06:23	wagjo	yes the reflection is a big tradeoff here
06:23	Bronsa	(let [x (x.)] {:foo (.foo x) :bar (.bar x)}) vs (zipmap [:foo :bar] ((juxt (memfn ^x foo) (memfn ^x bar)) x))
06:23	Bronsa	I would never write the latter, there's really no advantage
06:28	wagjo	egli: Bronsa: how about using bean for this?
06:29	wagjo	,(try (/ 1 0) (catch Exception e (bean (aget (.getStackTrace e) 0))))
06:29	clojurebot	wagjo: Titim gan éirí ort.
06:29	wagjo	,(try (/ 1 0) (catch Exception e (bean (aget (.getStackTrace e) 0))))
06:29	clojurebot	wagjo: Titim gan éirí ort.
06:33	Bronsa	wagjo: that might be a good idea however I remember bean not caching the values, maybe I'm just mis-remembering though
06:34	egli	wagjo: seems like a clever idea. Maybe too clever though, i.e. border line obfuscating for such a simple use case
06:35	Bronsa	,(def a (Exception. "foo"))
06:35	clojurebot	#'sandbox/a
06:35	Bronsa	,(def b (bean a))
06:35	clojurebot	#'sandbox/b
06:35	Bronsa	,(seq (:stackTrace b))
06:35	clojurebot	(#<StackTraceElement sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)> #<StackTraceElement sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)> #<StackTraceElement sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)> #<StackTraceElement java.lang.reflect.Constructor.newInstance(Constructo...
06:35	Bronsa	,(.setStackTrace a (into-array StackTraceElement []))
06:35	clojurebot	nil
06:35	Bronsa	,(seq (:stackTrace b))
06:35	clojurebot	nil
06:35	Bronsa	yeah, I really don't like bean because of this
06:36	Bronsa	,(instance? clojure.lang.IPersistentCollection b)
06:36	clojurebot	true
06:36	Bronsa	but it's actually mutable
06:36	wagjo	heh
06:36	clojurebot	It's greek to me.
06:37	minora	ciao
06:37	minora	!list
06:39	minora	\|list
06:39	Bronsa	minora: that won't work
06:40	minora	why dont work?
06:41	Bronsa	minora: that's not a command implemented in any bot here. are you sure you're in the right channel? this is about the clojure programming language.
06:41	minora	ok thanks you
06:42	minora	bye
07:55	noncom	i have some questions regarding google guava
07:55	noncom	1) is using google guava eventbus a good practice for clojure?
07:55	noncom	2) does it have any advantages/disadvantages to core.async?
07:56	noncom	3) does anyone have actual experience with that?
07:56	agarman	never used guava in Clojure. Used it a lot in Scala & Java.
07:56	mavbozo	i think stuart halloway and rich hickey found guava good enough to use in datomic
07:56	mavbozo	but i don't know if they use guava's eventbus
07:57	noncom	datamic is too, mainly a java program afaik
07:58	justin_smith	the fact that guava eventbus uses annotations makes it a bit less convenient from clojure
07:59	tcrayford____	noncom: datomic is mostly clojure from my understanding
07:59	justin_smith	annotations can be done from clojure, but it's a little awkward
07:59	tcrayford____	noncom: I use guava for yellerapp.com (just the caching though). It's been good so far
07:59	tcrayford____	(my api's 99th percentile response latency is ~300 microseconds, primarily because of guava caching)
08:00	noncom	tcrayford____: so, you say it is fast?
08:00	tcrayford____	noncom: well, the cache is fast enough for my purposes at least ;)
08:01	tcrayford____	noncom: no judging at all on the rest of the library, I use like 1% of it
08:01	noncom	ok, so yes, eventbus is based on annotations, which would look strange in clojure i think (never done them like that)
08:01	noncom	tcrayford____: is yellerapp.com part where you use them written in clojure or java?
08:02	tcrayford____	I think many folk would recommend core.async or looking at the j.u.c queues (which are the queues datomic uses internally)
08:02	tcrayford____	noncom: I do not use eventbus, just guava's caching. It's all clojure
08:02	noncom	ah, got it. just caching :)
08:02	justin_smith	tcrayford____: exactly - core.async for convenience / clarity, j.u.c queues when you need more perf
08:03	tcrayford____	or the disruptor or whatever. There are a lot of options for in memory java queues with different tradeoffs
08:03	justin_smith	right
08:04	justin_smith	is disruptor really usable from clojure? it has some weird constraints to go with that blazing performance
08:04	tcrayford____	(http://research.neustar.biz/tag/disruptor/ covers a buncha research around them [disclaimer, from a friend's company])
08:04	tcrayford____	justin_smith: it is, afaik. No annotations there, just a lot of mutability
08:04	justin_smith	gotta love ringbuffers :)
08:06	noncom	how much lower performance can i expect from core.async vs j.u.c ?
08:06	noncom	(if it is answerable at all)
08:06	tcrayford____	depends entirely on your use case, machine configuration, jvm etc
08:07	tcrayford____	they're both pretty quick though
08:07	justin_smith	noncom: I'd say don't worry about it until you have a bottleneck. Sadly I don't have a concrete measured comparison. I should make one one of these days.
08:07	tcrayford____	iirc core.async benches at something like 12m channel transfers/s or so (but that's from memory, and I didn't verify the benchmarks like I do these days)
08:07	tcrayford____	(and those benches were likely not on the machines you're gonna be running in prod either)
08:08	noncom	oh, well, that far covers my needs, i think :)
08:08	tcrayford____	likely most apps don't need anything like that though haha :)
08:08	tcrayford____	yeah. I'd just use core.async, it's an easy reach for most clojure devs, is well adopted etc
08:09	noncom	yes, i just want to choose a mechanism for messaging inside the app, that won't be even a 100 channels and no big data sent over it, just small messages
08:09	noncom	i guess, i'll pick core.async again for that :)
08:09	tcrayford____	neat!
08:09	tcrayford____	glad we could help :)
08:09	noncom	thanks :)
08:09	justin_smith	tcrayford____: I've noticed performance loss from using core.async. Maybe it's related to the core.async state machine and hotspot? not sure. There's more going on than just channel throughput anyway I think.
08:11	noncom	justin_smith: what was your scenario?
08:11	tcrayford____	justin_smith: the go macro will most likely prevent inlining because of the code bloat it generates if you put a lot of code in it
08:12	tcrayford____	noncom: but again, the JVM is very fast, and it's likely that ain't gonna matter at all for your use case
08:12	noncom	yeah, my case is definitely the "light" one
08:13	noncom	i would go with j.u.c on something heavyweight then
08:13	justin_smith	noncom: core.async coordinating requests / caching on an image resize server
08:14	justin_smith	it was more about latency, even for cached result
08:14	justin_smith	s
08:14	justin_smith	also, I should do some more focused benchmarks, because it could have been something else stupid in my implementation logic :)
08:25	arav93	Hi! :)
08:26	dysfun	i need to maintain some dependency information. is there a library that aids in performing cycle detection?
08:27	Bronsa	dysfun: tools.namespace has a namespace that handles dependency graphs
08:27	dysfun	yes, which uses 'component'
08:27	dysfun	but i'm struggling to reason about the behaviour when you create cycles
08:27	Bronsa	tools.namespace doesn't use component
08:27	dysfun	sorry, 'dependency'
08:28	dysfun	https://github.com/stuartsierra/dependency
08:29	dysfun	ah, it throws an exception. i hadn't spotted that
08:29	stuartsierra	The 'dependency' is just a copy of the dependency graph from tools.namespace
08:29	dysfun	that's acceptable
08:30	stuartsierra	Both are just a small adaptation from Clojure's hierarchy graph functions.
08:30	dysfun	nod
08:30	dysfun	thanks
08:33	dysfun	one of the things i love about clojure incidentally is that you randomly bump into the people who write the libraries you use on irc. it's quite a nice thing :)
09:07	noncom	i am trying to find the best way to write the macro: https://www.refheap.com/98107
09:07	noncom	please could someone answer questions 1 and 2, written in the comments?
09:08	dysfun	you're worried about performance loss using apply?
09:08	noncom	the aim of the macro is to accept a [] of functions and apply the args to all of them, filtering out nils
09:08	dysfun	i would suggest not to be in the general case
09:08	noncom	dysfun: yeah, also, using apply implies using (into []), at least the way i have managed to make it work with apply. can i avoid (into [])
09:08	noncom	?
09:11	Bronsa	noncom: http://sprunge.us/MSOD?clj
09:12	noncom	Bronsa: wow
09:13	noncom	so actually macros can have several `() places..
09:13	noncom	did not know that
09:14	Bronsa	or even http://sprunge.us/UQUF?clj
09:14	noncom	but that's logical..
09:14	Bronsa	noncom: ` has nothing to do with macros
09:14	noncom	yes, i know.. but i just could not think of it this way :)
09:15	noncom	so, list* is even better..
09:38	justin_smith	noncom: why not ((apply juxt (filter identity funs)) args)
09:40	justin_smith	,((apply juxt (filter identity [nil + - nil * /])) 5 3)
09:40	clojurebot	[8 2 15 5/3]
09:46	justin_smith	even if you decide a macro is better, juxt can eliminate your apply / into
09:47	justin_smith	eg. fns-apps `((juxt ~@fns) ~@args)
09:49	noncom	justin_smith: hmm, not really familiar with juxt much :) but i knew that a moment would come to get to know it better..
09:50	justin_smith	noncom: the above should replace your fns-apps binding in the let block. The difference is it returns a vector of all the results, so you would want a `(peek ~fns-apps) at the end instead of the do
09:50	justin_smith	(if you only wanted to return the result of the last function)
09:51	dm3	is there a way to sidestep git tag signing on lein vcs tag?
09:52	noncom	yeah, juxt returns a vector.. well, in my particular usecade all fns are pure side-effects (it is an IO stuff), but as i make this macro into my library of useful things, i guess, juxt is a nice thing to have since it is more general in returning a vector, not making assumptions on fns being side-effetless
09:52	justin_smith	yeah, if you are typically ignoring the return value, may as well just return the vector if you use juxt
11:23	nsjph	what's a good file-backed key value store i can use with clojure?
11:24	nsjph	aside from just spitting out EDN to disk
11:34	noncom	hsjph: probably none.. widely known.. but why not edn?
11:35	justin_smith	this makes me wonder if anyone has done a simple edn -> directory structure mapping
11:36	nsjph	noncom: i don't feel like thinking about thread-safety and database-like resiliency for a flat file
11:36	nsjph	i also dont feel like using sqlite here
11:37	justin_smith	numbers, strings would become files - the tricky part would be hash-maps with composite keys...
11:37	nsjph	so i was wondering what key-value stores with file-based backends (ala sqlite) are about
11:37	justin_smith	nsjph: there's mongo, if you are aware of the pitfalls and don't mind them
11:37	justin_smith	congomongo
11:37	nsjph	justin_smith: oh, and i dont want to install a database server
11:37	noncom	nsjph: maybe http://www.h2database.com/html/faq.html#database_files ?
11:37	nsjph	particularly mongo ;)
11:38	justin_smith	well, for sql, embedded h2 is an option, yeah
11:38	nsjph	i should probably just bite the bullet and use either sqlite or h2
11:38	justin_smith	with a file backend
11:38	justin_smith	nsjph: couchdb?
11:39	nsjph	no network server :)
11:39	noncom	orient db also. they claimed to provide a local db mode
11:39	nsjph	i've also used couchdb, didn't mind it
11:39	nsjph	not a bad db
11:39	hiredman	http://hiredman.github.io/Amontillado/
11:40	nsjph	interesting
11:41	justin_smith	(inc hiredman)
11:41	lazybot	⇒ 74
11:41	justin_smith	that looks great
11:43	noncom	justin_smith: so, what did you say about mapping edn to filesystem?
11:43	noncom	what is the use about this?
11:45	justin_smith	noncom: it would mean that the persistent data structure operations could be mapped to file system operations
11:46	justin_smith	including cheap immutable update
11:46	justin_smith	theoretically
11:46	justin_smith	maybe it's a silly idea
11:46	noncom	justin_smith: wow, why did not someone just made that? are there any problems with that?
11:46	justin_smith	there's probably some pitfall that I am overlooking
11:47	justin_smith	eg. something that works in the jvm but not on a file system level
11:47	justin_smith	maybe it's just the added difficulty of making it work on more than one OS (because they don't use the same filesystems, so they have different rules regarding locking etc.)
11:48	noncom	java.nio.Files seems to target just that - working flawlessly on any fs
11:48	noncom	(available from java 7 and up)
11:48	justin_smith	clojure targets 1.5
11:48	justin_smith	err, 5 by that system :)
11:48	noncom	but we can use any java version from inside clojure anyway...
11:57	sdegutis	Is there any chance for a ClojureScript compiler that doesn't depend on the Google Closure Compiler or Library at all?
11:57	sdegutis	I'd love to just write Clojure and let it compile down into pure JavaScript.
11:59	justin_smith	sdegutis: what about something like scriptjure? https://github.com/arohner/scriptjure
12:00	sdegutis	justin_smith: not a bad idea
12:00	sdegutis	thanks
12:00	justin_smith	it doesn't do the clojure semantics, it's just a syntax translator
12:00	sdegutis	That's fine, I don't mind JS semantics.
12:00	sdegutis	I'm just tired of managing commas.
12:01	justin_smith	sdegutis has forsaken immutability
12:02	sdegutis	justin_smith: "If a tree falls in the woods, does it make a sound? If a pure function mutates some local data in order to produce an immutable return value, is that ok?" - Rich Hickey
12:02	justin_smith	:)
12:02	sdegutis	justin_smith: I just use _.cloneDeep(json) for immutability
12:02	sdegutis	where _=lodash
12:02	sdegutis	justin_smith: check out https://github.com/sdegutis/mybudget/blob/master/database.js btw, it was designed inspired by clojure's immutability
12:03	justin_smith	cool
12:03	sdegutis	I love that the immutability aspect made undo/redo into one-liners
12:03	sdegutis	On the other hand, it's probably ridiculously inefficient compared to using something like Immutability.js
12:03	sdegutis	(which I assume does data-structure sharing etc)
12:04	justin_smith	yeah, proper persistent data structures
12:19	puredanger	justin_smith: clojure targets Java 1.6, not 1.5
12:19	justin_smith	puredanger: is that a recent change?
12:19	puredanger	Clojure 1.6
12:19	justin_smith	oh, TIL, thanks
12:20	justin_smith	(inc puredanger)
12:20	lazybot	⇒ 34
12:20	puredanger	Clojure 1.7 will also target Java 1.6+
12:20	danielglauser	puredanger: what Java version does Clojure 1.7 target?
12:20	justin_smith	puredanger: still supports the point I was making about 1.7 features :)
12:20	puredanger	Clojure 1.8 will likely change to target Java 1.7+
12:21	puredanger	Java 1.7 public updates end next month
12:21	puredanger	http://www.oracle.com/technetwork/java/eol-135779.html
12:22	puredanger	Java 1.6 public updates ended 2 years ago
12:22	puredanger	if you want to use 1.7+ stuff but fall back to something else, search for the compile-if macro in Clojure's source
12:35	eflynn	So I’m writing a scheme interpreter in clojure, and i’m wondering how i should handle mutable state
12:36	eflynn	I was thinking something like (eval exp env) -> (exp, env2)
12:36	eflynn	where changes in the environment are returned
12:36	eflynn	any thoughts
12:50	justin_smith	eflynn: one advantage of that (rather than an implicit global env, or env represented as a bunch of mutable objects) is that it is flexible enough to map cleanly to the other alternatives
12:51	eflynn	justin_smith: map as in rewrite?
12:52	justin_smith	eflynn: you can implement a global env object, or separate mutable objects for each variable, based on the explicit passing of state
12:52	justin_smith	the translation does not work as well going the other way
12:52	justin_smith	you can't really model explicit state passing using a global env or mutable objects, at least not cleanly
12:53	eflynn	explicit state passing with a global env wouldn’t make sense
12:54	justin_smith	eflynn: right, I am saying that given the implementation of explicit state passing, you can implement the others
12:54	justin_smith	but not visa versa
12:54	justin_smith	so it's a superset of the others
12:54	eflynn	ok
12:55	justin_smith	it would involve a wrapper function most likely
12:55	justin_smith	but it's harder to write an unwrapper function :)
14:33	dbell	long time no see clojurists...is there a way to get the # of args a fn takes? I've dug around in the source a bit but haven't found anything
14:34	dnolen	dbell: you can only do that via the meta of a var
14:34	dnolen	,(-> #'first meta :arglists)
14:34	clojurebot	([coll])
14:34	dnolen	dbell: ^
14:35	dbell	how about in cljs?
14:35	dbell	what w/no vars
14:36	dnolen	dbell: the will work in CLJS too
14:36	dnolen	s/the/that
14:41	justin_smith	,(defn inane-arities [f] (keep #(try (apply f (repeat % nil)) % (catch clojure.lang.ArityException e nil) (catch Exception e %)) (range 1024)))
14:41	clojurebot	justin_smith: Pardon?
14:41	justin_smith	:P
14:41	justin_smith	anyway, that code is stupid, but it returns all argument counts the function accepts below 1024
14:41	justin_smith	don't use it, just a proof of concept
14:45	dbell	justin, ha, yeah, i thought of that too, but it felt, uh, well, you know
14:45	justin_smith	a little dumb?
14:45	dbell	ha, yeah
14:45	dbell	david, i must have misunderstood, but i can't seem to access vars in cljs
14:46	dbell	justin---i might take that and use it to make a lookup table
14:47	justin_smith	haha, oh man...
14:59	justin_smith	and thanks to that silliness I learn...
14:59	justin_smith	,(conj)
14:59	clojurebot	[]
15:02	justin_smith	(conj Double/NaN)
15:02	justin_smith	,(conj Double/NaN)
15:02	clojurebot	NaN
15:31	amalloy	dnolen: anything i should be doing to make http://dev.clojure.org/jira/browse/LOGIC-167 more palatable? it's not like you to leave a patch unmerged for longer than ten minutes
15:31	dnolen	amalloy: nah nothing to do just been busy with other stuff
15:31	amalloy	okay
15:31	dnolen	other people have pinged me for another core.logic release since various fixes are still sitting around
15:31	dnolen	will cut a release on Friday
15:33	Beamed	I hope you guys don't mind me asking, but I was having trouble with a random 4Clojure problem and was hoping to ask for some advice
15:33	dbell	fire away
15:34	Beamed	basically, it's an implementation of interpose, and my solution is just (fn [val & seq]( reduce #(concat %1 val %2) seq) )
15:35	Beamed	but for some reason, that just returns the passed sequence, rather than concatenating it with val :/
15:35	Beamed	for example, given 0 [1 2 3] it should provide [1 0 2 0 3] , but it just returns [1 2 3]
15:36	justin_smith	that's odd, because (concat 1 0 2) shouldn't work
15:36	amalloy	Beamed: you probably mean [val seq]
15:36	Glenjamin	,(concat 1 0 2)
15:36	Beamed	I ran it through the lein repl and it does the same justin
15:36	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: Don't know how to create ISeq from: java.lang.Long>
15:37	Glenjamin	ah, i see why it doesn't error
15:37	amalloy	justin_smith: seq here is [[1 2 3]], not [1 2 3] as intended
15:37	justin_smith	Beamed: it worked by accident, because of the issue amalloy points out
15:37	Beamed	amalloy - I think that's why it's not crashing; I was a dope and made seq a variadic param. Doy
15:37	amalloy	right
15:37	Glenjamin	the & and missing initial case combine
15:38	Beamed	thanks, I knew it was something like that.
15:40	amalloy	Beamed: happy 4clojuring
15:50	Beamed	hah, and then I see it was as simple as combining but-last and interweave >_<
15:51	amalloy	Beamed: well. the thing about 4clojure is, you solve it in whatever way advances your understanding best
15:51	amalloy	you wanted practice using reduce, so you used reduce
15:52	amalloy	that kind of flexibility is one of my favorite things about it
15:52	blake_	This is very true. You can go back and solve the same problem multiple times to gain insight into different mechanics.
15:54	amalloy	for example when i solved 4clojure problems i already felt quite comfortable with combining built-in functions like map, filter, reduce, whatever, so i probably would have easily seen a solution like the second one you mentioned. but i wanted more practice with manual recursion, so i solved the problems that way instead
15:56	Beamed	Yeah, you're right - I'll comb through ti again when I know more about all the built-in functions to see how simple and elegant I can re-do it - for now, I'll try learning them at all.
15:56	Beamed	Thanks!
15:56	puredanger	as always, http://clojure.org/cheatsheet is a great resource
16:00	amalloy	is (some-> x (f)) a better or worse way to write (when x (f x))?
16:01	justin_smith	amalloy: I would usually express that as (and x (f x)) but maybe that's weird
16:01	puredanger	the when is clearer to me at a glance
16:01	dbell	i would do what justin would do
16:02	dbell	but some-> isn't well known
16:02	dbell	so maybe not such a bad thing
16:02	amalloy	justin_smith: i don't like the and at all
16:02	ToxicFrog	amalloy: I'd write that as (some-> x f) or (and x (f x)), but I prefer the former.
16:02	amalloy	but i guess i haven't mentioned whether f is for side effects or values (it's side effectts)
16:03	justin_smith	oh yeah, I wouldn't use and for side effects
16:03	amalloy	justin_smith: another thing is, to use when or and you have to actually name the thing; with some-> you can get away with never naming it
16:04	justin_smith	well, you could generate it in context the same as you did with some->
16:04	justin_smith	or am I missing something there?
16:04	justin_smith	ahh, right
16:04	justin_smith	don't mind me, I get it now
16:04	justin_smith	yes, that's a clincher for some->
16:08	ToxicFrog	,(doc when)
16:08	clojurebot	"([test & body]); Evaluates test. If logical true, evaluates body in an implicit do."
16:08	ToxicFrog	Oh that's handy.
16:08	noncom	i am writing an app that has a controlling messaging system in it, realized with core.async. i am thinking about using vectors for messages, where the first kw is the message id and then goes some parameters.
16:09	noncom	my wuestion is: will constructing a vector for each message be an expensive operation?
16:09	amalloy	noncom: are you writing the firmware for a pacemaker?
16:10	noncom	basically, a multimedia app. for example, i plan to use such messages for spreading mouse cursor parameters into the app
16:10	justin_smith	noncom: depending what you do with it, the vector overhead isn't likely to be a big deal. Couldn't hurt to benchmark vector vs. list, it shouldn't be hard to write your code so they could be swapped out
16:10	noncom	or to facilitate messages between ui elements
16:10	noncom	think of like a complex 3d game level scripting
16:11	amalloy	noncom: it was a rhetorical question, meant to imply: "unless you are writing software where the delay might kill somebody, focusing on microoptimizations like trying to reduce the number of vectors you allocate is pointless folly"
16:11	puredanger	how are you going to use the data (indexed access, etc)?
16:12	amalloy	additionally there are zillions of vector allocations you can't do anything about going on all the time, so removing some of yours won't have any substantial impact
16:12	noncom	oh :D
16:13	noncom	yes, data in the messages are access and some params
16:13	noncom	more like bash commands with params. a similar kind of load/idea
16:14	puredanger	if you need indexed access, then the cost of that (or not getting that) is probably more important than constructing the vector. but if you're really trying to push memory/perf, you could also consider arrays.
16:15	puredanger	in general, any "which data structure" question in clojure is often better approached first from the "how will it be used" angle
16:15	amalloy	(inc puredanger)
16:15	lazybot	⇒ 35
16:16	noncom	well, like generating and destructuring 1000 []/s is ok?
16:17	puredanger	sure :)
16:17	puredanger	(I have no idea really)
16:17	puredanger	why guess when you can test?
16:18	noncom	oh sure :)
16:18	amalloy	noncom: put an abstraction layer in between your logic and the data structure it manipulates, and then you can change it if you end up needing to do something else
16:18	noncom	right, that's nice !
16:20	amalloy	personally my default choice would be to build more objects, not fewer, something like {:cmd "ls" :args ["/var/lib"]}. but it'll all depend on how you want to use your data, like puredanger says
17:38	imanc_	is there a way to break into the repl in some executing code similar to python's import pdb; pdb.set_trace() ?
17:45	justin_smith	imanc_: you can get close with jdb (but it's not clojure aware, you only see the jvm level stuff) or with cursive (not sure how extensively the debugging is implemented, but I know it is present)
17:46	justin_smith	and I meant to add, the debug tooling in cursive is more extensive than with any other clojure environment I know of
17:49	imanc_	OK, cursive sounds like the way forward :)
18:39	farhaven	asdffffff
18:39	farhaven	.
18:50	cfleming	imanc_: With Cursive you can set breakpoints and when it stops you can evaluate expressions
18:50	cfleming	imanc_: It's not quite a full REPL (yet) but it's pretty useful
18:51	cfleming	imanc_: And you can break on uncaught exceptions etc
18:51	cfleming	imanc_: I'll be talking about it and demoing it at Clojure/West actually
18:54	the_danko	greetings
18:55	the_danko	anyone know how to do a "ctrl-R" style command history search in the cursive REPL?
18:56	cfleming	the_danko: Greetings. You're looking for Tools->REPL->Search REPL History
18:57	the_danko	sweet, thanks
18:57	the_danko	will remap that guy
18:57	cfleming	the_danko: Narrows down on typing, when you select it'll copy the command to the REPL editor or shift-enter will execute immediately
18:57	the_danko	also, what does this load forms in repl namespace fellow do?
18:58	the_danko	cfleming i was hoping you would be around!
18:58	cfleming	the_danko: You mean Run top form in REPL?
18:58	cfleming	the_danko: I saw the IRC bat-signal
18:58	the_danko	ha
18:59	the_danko	i mean in settings
18:59	cfleming	the_danko: Run top form in REPL finds the top-level form that your cursor is in, and sends that to the REPL for execution
18:59	the_danko	under load out of date files transitively
18:59	cfleming	the_danko: Ah
18:59	cfleming	the_danko: That controls the namespace that's used when executing forms from the editor.
19:00	michaniskin\|BNC	is there a library that will return #'clojure.core/ex-info, given the string "clojure.core$ex_info" (but for the java class name of any clojure function)?
19:00	the_danko	cfleming so on this subject, i do load file in repl a lot as i am working.
19:00	cfleming	the_danko: So you send a form from the editor using Run top form or whatever - if that setting is checked, the form will be executed in the current namespace of the REPL. If it's not checked, the form will be run in the namespace of the file the form came from.
19:01	the_danko	cleming that is idomatic, no? but then i have to do ('using editor.namespace)
19:01	the_danko	idiomatic
19:01	the_danko	am i doing something wrong?
19:02	the_danko	use
19:02	the_danko	not using
19:02	cfleming	the_danko: I'm not sure what you mean - you're talking about when you load a file in the REPL?
19:02	the_danko	yeah so i have a file cljlearn.core
19:02	the_danko	and my repl in the user namespace
19:03	the_danko	and when i change a function in cljlearn.core and reload it
19:03	the_danko	sorry i mean when i add a function to cljlearn.core
19:03	the_danko	i have to do (use 'cljlearn.core)
19:03	the_danko	again
19:03	justin_smith	the_danko: that won't help
19:03	justin_smith	because you have loaded the ns already
19:04	the_danko	well if i add something to the namespace
19:04	the_danko	a new function
19:04	the_danko	then i have to reload it
19:04	justin_smith	maybe, but use won't reload
19:04	the_danko	basically, i want to know what the best practice is as far as what namespace to keep the REPL in
19:04	the_danko	relative to the file i am working on in the editor
19:05	cfleming	Yeah, in that case you will have to, because the symbols are all interned at the point you (use...)
19:05	cfleming	So you can just switch to that namespace and work in there
19:05	the_danko	cfleming is that what you do?
19:05	cfleming	Or you can create an alias to it, and use (alias/function ...)
19:05	the_danko	(in-ns 'cljlearn.core)
19:06	cfleming	the_danko: Yeah, or there's a Cursive command to switch to the current ns
19:06	the_danko	cfleming and then (use 'clojure.core) and a bunch of other sh*t?
19:06	cfleming	the_danko: It depends what I'm doing. I usually use aliases
19:06	the_danko	so in the repl you set up an alias
19:06	justin_smith	the_danko: (clojure.core/refer-clojure) because use won't work if clojure isn't referred yet
19:07	the_danko	ha yeah i mean so that seems like a pain
19:07	justin_smith	the_danko: but if the ns has already been created properly, you won't need to do either
19:07	cfleming	Cursive auto-requires in the REPL, so if I'm typing (str/tr and I complete it to str/trim, Cursive will auto-require clojure.string :as str, as long as there's an example of that somewhere in your project
19:08	the_danko	interesting
19:08	cfleming	the_danko: But I'm mostly working on Cursive itself, which is a relatively massive project, so my use case is different to working in a single namespace on a smaller project
19:08	the_danko	yeah i bet
19:08	cfleming	the_danko: For that, aliases work best
19:08	the_danko	for which?
19:08	the_danko	the large project?
19:09	cfleming	For bigger projects
19:09	cfleming	For a smaller one, I'd probably just switch to the ns and work there
19:09	the_danko	well my project won't always be small
19:09	the_danko	ok thanks
19:09	cfleming	the_danko: Sure, but there's nothing to stop you changing how you work at that point
19:10	the_danko	good poiont
19:10	the_danko	point
19:10	cfleming	the_danko: If you really want to work in user, I'd recommend aliases, I think
19:10	the_danko	so i open up the repl
19:10	cfleming	the_danko: But I just do whatever's easiest for what I'm working on at the time
19:10	the_danko	so what all is in user by default?
19:11	the_danko	core
19:11	the_danko	that i have to add when i work in a given namespace
19:11	the_danko	nevermind, i'll figure that out myself
19:11	the_danko	not a high value question
19:11	cfleming	core is always there, there's a few other things like pprint
19:11	cfleming	One sex
19:11	cfleming	Oooops
19:11	cfleming	One sec, rather
19:11	cfleming	That's a freudian slip if ever I saw one
19:12	amalloy	cfleming: i was quite embarrassed as a teenager when i wrote "afk for a sex"
19:12	amalloy	even worse than yours
19:13	michaniskin\|BNC	a "freudian cock" as we say in the land of recursion
19:14	the_danko	so cfleming, do you use the debugger at all?
19:14	the_danko	cfleming, like one does in java?
19:16	cfleming	the_danko: (apply require clojure.main/repl-requires) will set any ns up as user is
19:16	the_danko	cfleming awesome, thanks!
19:16	cfleming	amalloy: When I was at school in the US while my folks were on sabattical, I was 14 I think, I asked a girl in my class for a rubber
19:16	amalloy	cfleming: that's neat, i didn't know that
19:17	amalloy	cfleming: ha, a classic cross-pond mixup
19:17	cfleming	amalloy: Which in the civilised world is an eraser
19:17	amalloy	i hope you asked for a fag at some point during a visit as well
19:17	cfleming	amalloy: I also had a similar "bush" incident
19:17	amalloy	cfleming: have you checked to see if you are in a romantic comedy?
19:18	justin_smith	cfleming: a friend of mine went to australia from the US, did not know why everyone thought her story about falling on her fanny was so funny
19:18	cfleming	amalloy: I hope so, I'm hanging out for the happy ending
19:18	cfleming	justin_smith: Another classic
19:18	justin_smith	pants is another good one
19:18	amalloy	thong
19:19	cfleming	the_danko: Yeah, I use the debugger all the time
19:19	amalloy	really it's a wonder we can talk to you folks at all
19:19	cfleming	yeah, no doubt - especially as teenagers
19:19	the_danko	cfleming sweet, look forward to trying that
19:19	the_danko	cfleming i had to buy these http://www.amazon.com/gp/product/B003Y95IVU/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
19:20	the_danko	cfleming for my all black das in order to keep up with your keyboard shortcuts.
19:20	the_danko	cfleming ha, definitely worth it though.
19:20	amalloy	the_danko: huh? do you have an azerty layout or something?
19:20	cfleming	the_danko: Ha, yeah, paredit with a das would be a challenge
19:20	the_danko	i know where the letters are
19:21	the_danko	but i dont have great memory yet for } ] f12
19:21	the_danko	etc
19:21	the_danko	as cfleming says, it's a little tough flying blind
19:21	the_danko	cfelming finally i was able to admit i needed help. it took a long itme.
19:21	cfleming	That's always the first step in any recovery
19:22	blake_	cfleming: The auto-require is just wonderful.
19:22	cfleming	blake_: Yeah, I love that - I use it all the time
19:23	blake_	cfleming: Money's just burning a hole in my pocket, dude...
19:23	cfleming	blake_: Arg, I know
19:24	blake_	cfleming: heheh...I'm being very selfish here...I really want to encourage continuing development. =P
19:25	cfleming	blake_: hehe, yeah - development is continuing!
19:25	blake_	cfleming: Groovy.
19:25	cfleming	blake_: Development speed isn't limited by money as much as by only having 24 hours a day, and having a baby daughter
19:26	blake_	cfleming: Yeah, I get that. They're cute and exhausting and don't really care about your projects. =P
19:27	cfleming	blake_: I commented to a friend that kids will soak up all the time you let them. He said yeah, they're like Farmville
19:27	cfleming	He's a fountain of wisdom
19:27	blake_	cfleming: lol...yeah...a regular Dr. Spock.
19:54	CaptainLex	Is there a good resource out there for relative beginners on how to use the REPL to debug? I hear it's very powerful and I think I'm in need of that power
19:54	CaptainLex	I'm actually working in CLJS but it'd be good to know for later CLJ projects
19:56	bridgethillyer	I found this useful: http://blog.jayfields.com/2014/01/repl-driven-development.html
19:56	Morgawr	mmm.. I recently updated clojurescript for my project and now it's telling me a lot of warnings about cljs.core/update being shadowed by some functions I have (which are called 'update')
19:57	Morgawr	the problem is... where does update come from? It's not in the clojure.core library...
19:57	Morgawr	or at least I can't find it. I see it in clojurescript
19:57	Morgawr	is this something new that I missed?
19:58	michaniskin\|BNC	Morgawr: https://github.com/clojure/clojurescript/blob/master/src/cljs/cljs/core.cljs#L4142
19:59	Morgawr	michaniskin\|BNC: Yes, I know, as I said in my question :P
19:59	Morgawr	I see it in clojurescript, but where does it come from?
19:59	Morgawr	it's not in clojure
20:00	Morgawr	looks like a wrapper around using assoc with mutable javascript data.. ?
20:00	CaptainLex	michaniskin\|BNC: Thanks
20:00	CaptainLex	!
20:01	enaden	t
20:11	tvanhens	is there any way to execute a series of jdbc requests in a transaction without using a macro in the jdbc library?
20:12	amalloy	tvanhens: i mean, anything you can do with a macro can be done without a macro, by writing out whatever the macro expands to
20:13	tvanhens	good point. was wondering if there was a function option in that lib before I start hacking with that approach
20:14	hiredman	what would you expect the function to do?
20:15	amalloy	tvanhens: db-transaction* looks like the thing to use?
20:15	amalloy	it takes in a database and a thunk, and executes that thunk while inside a transaction
20:15	hiredman	the bounds of jdbc's transaction macro go a long towards delineating a good transaction
20:16	hiredman	amalloy: if tvanhens wants that there is also the option of (fn [db fun] (with-db-transaction [foo db] (fun foo)))
20:16	amalloy	true
20:17	hiredman	if your code does fit that shape, you might end up having a bad time with transactions
20:17	hiredman	doesn't
20:17	tvanhens	thanks guys the problem with that approach hired is all my query definitions are in data. I'm trying to create all their jdbc calls with generated code so the macro is kinda throwing a wrench in things
20:19	tvanhens	db-transact* looks promising
20:19	hiredman	the thing to keep in mind is transactions can fail, so how do you encapsulate the execution of the code for the transaction in a package that is retryable on failure
20:20	lvh	Does anyone have any reccomendations for getting useful error messages out of core.test? as opposed to actual: false :/
20:20	lvh	core.logic's featurec does almost what I want, but also won't give me a useful error message.
20:21	hiredman	lvh: the messages you get are a result of what you put in
20:21	lvh	hiredman: Sure, that's why I'm asking for suggestions on how to make it better :)
20:21	hiredman	if you are comparing two large structures using =, you get a single value back, true/false
20:22	hiredman	if you compare different keys or positions or whatever by themselves you get more information (multiple values)
20:22	hiredman	(is (= a b)) vs (is (= (get a :foo) (get b :foo))
20:23	lvh	ah; so just stuff multiple is'es into a testing block?
20:23	hiredman	that works for comparisons, but if you do some large calculation outside of the is, and then hand it to the is, all the is has is that value
20:24	amalloy	someone at geni wrote some kind of macro that converted (is (= x {:a 1 :b 2 :c 3})) into three different calls to is
20:24	hiredman	https://github.com/pjstadig/humane-test-output is also a thing (limited by the information you give to the is macro) you can also look at using are instead of is
20:24	amalloy	which was kinda handy
20:25	hiredman	amalloy: if I remembered the syntax to are, I think you could do that pretty quick
20:25	amalloy	yes
20:26	justin_smith	(is (= [nil nil] (take 2 (data/diff a b)))
20:26	hiredman	(are [x y z] (= (get y x) (get z x)) [:foo a b] [:bar a b] ...)
20:26	amalloy	justin_smith: why take 2?
20:26	justin_smith	amalloy: the third value is the items the two had in common
20:27	justin_smith	less likely to need to assert anything about that
20:28	justin_smith	unless you expected a specific difference I guess?
20:29	justin_smith	but of course the advantage there is that the failed test shows exactly the differences that are present but not expected
20:29	amalloy	the way 'are works makes me sad. the clojure.walk calls don't understand shadowing or quoting
20:30	amalloy	i wish we could get macrolet as part of the compiler, rather than clojure.tools.macro needing to reinvent it
20:33	Morgawr	I'm trying to wrap my head around testing in clojurescript... I run "lein cljsbuild test" and it says 1 test was run containing 1 assertion (which is (is 1 2) to make it fail) which doesn't fail... and I need to ctrl+c the commad to kill it because it doesn't terminate
20:33	Morgawr	am I doing something wrong? (answer is very yes)
20:34	Morgawr	oh, I guess is needs (is (= 1 2))
20:35	Morgawr	now I only need to figure out how to make the command exit at the end...
20:36	scottj	Morgawr: maybe it is watching the files to rerun when they change?
20:38	Morgawr	scottj: weird, I just tried using rhino instead of phantomjs and it exits properly
20:38	Morgawr	with phantomjs it just hangs and waits
20:39	Morgawr	oh
20:39	Morgawr	I fixed it, I was missing :runner in the test command
20:39	Morgawr	now it works :)
21:24	vas	Hi I'm using datomic and trying to get relevant entities by supplying an author or eid ... but every time I query the db I get a :db.error/too-few-inputs ... https://www.refheap.com/98117
21:28	scottj	vas: I haven't used datomic, but I would guess ":in $ ?eid" is not what you want and is causing it to want an arg more than just the db connection, maybe?
21:28	scottj	vas: maybe you want :in [$ ?eid]
21:29	puredanger	that's correct
21:29	puredanger	I mean it's correct that :in [$ ?eid] is going to expect another arg after the db
21:30	puredanger	so pass eid at the end
21:32	owl-v-	hi
21:33	owl-v-	what's the math library I can use for matrix operations in clojure?
21:34	scottj	owl-v-: core.matrix afaik
21:35	scottj	and/or vectorz-clj
21:36	owl-v-	thanks
21:37	enn	If I want to use a local version of a (lein) project dependency, I can makes a checkouts directory. Is there any way to do something similar across projects, for a dependency that is defined in my profiles.clj?
21:48	gfredericks	enn: I can't tell how the second thing you described is different from the first thing
21:52	amalloy	it sounds like enn wants to have every project on the machine use a modified checkout
21:53	gfredericks	oooh I missed the profiles.clj part
21:53	amalloy	which is just not a good idea: publish the modified version, or at least install it locally, under a different groupid; then you can depend on it like a proper person
21:53	gfredericks	I read "project.clj"
22:27	enn	yeah, I guess it is time for me to figure out how to deal with maven locally
23:02	rufoa	I'm trying to turn two sequences [:k1 :k2 :k3] and [:v1 :v2 :v3] into a map {:k1 :v1 :k2 :v2 :k3 :v3}
23:02	rufoa	is there a neater way than this? (into {} (mapv vector [:k1 :k2 :k3] [:v1 :v2 :v3]))
23:03	Wild_Cat`	rufoa: zip?
23:03	amalloy	zipmap
23:04	amalloy	but also if you were going to do it your way, mapv is silly compared to just map
23:06	rufoa	ah i'd forgotten about zipmap! and you're right about mapv of course yes
23:06	rufoa	thanks!
23:14	enn	Since str returns something like "clojure.lang.LazySeq@e93c3" for a lazy sequence, why does it realize the sequence?
23:26	amalloy	e93c3 is the hashcode, which is based on the sequence's items
23:31	enn	ah
23:37	nicola1	i am trying to figure out why my clojure program won't exit after the last statement; any pointers on how what to do to figure this out?
23:37	nicola1	i put a println statement as the very last thing, it gets executed, so i'm looking for connections left open or things like that
23:38	godd2	nicola1 its possible that you're println'ing an infinite range?
23:38	nicola1	all i could find online is related to pmap/shutdown-agents, but i'm not using that
23:38	tomjack	kind of makes me sad when I need ~30G ram to chew a 1.6G file: https://www.refheap.com/e04a09f241c8c63bcd7b052ee
23:38	justin_smith	nicola1: shutdown-agents
23:38	godd2	I couldn't say without seeing the code
23:38	tomjack	wonder if there are obvious problems there besides, uh, using seqs
23:38	justin_smith	nicola1: if you have used futures, agents, etc. at all clojure won't shut down immediately unless you call shutdown-agents
23:38	tomjack	(whoops, s/soft/foo/ :( )
23:39	nicola1	i tried calling shutdown-agents at the end, didn't help :(
23:39	nicola1	i'm basically ingesting data from avro files into cassandra
23:40	nicola1	(let [connection ...] (doall (map #(ingest-into-cassandra connection %) filenames)))
23:40	justin_smith	tomjack: looks like a great use case for transducers rather than nested map / filter etc, if you can use 1.7
23:40	tomjack	yes, I just didn't want to write yet another reducers version of line-seq :(
23:41	justin_smith	nicola1: oh, I wasn't talking about pmap/shutdown-agents, just the regular shutdown-agents
23:41	tomjack	this run just finished, and luckily this box has 250G ram, but I'll try transducers next time
23:41	justin_smith	tomjack: you can keep the line seq part, but turn the rest into reducers, that will reduce your heap usage
23:41	tomjack	hmm. good idea
23:41	justin_smith	s/reducers/transducers that is, of course
23:41	nicola1	justin_smith: yes me too, i shouldn't have written "/" since it's clojure syntax - sorry about that
23:44	justin_smith	nicola1: ahh, yeah. shutdown-agents is needed not just for pmap, but if any code touches the pool, which includes futures, agents, pmap, reducers...
23:46	nicola1	justin_smith: i was just trying again to make sure, that's not it unfortunately
23:49	nicola1	i'll keep poking, thanks for your help
23:50	tomjack	justin_smith: well, it ran ~75% faster this time, and htop didn't show my heap growing (though I don't trust that _too_ much)
23:50	tomjack	thanks
23:51	tomjack	15min vs 3min ish, big difference!
23:51	tomjack	next time I'll try to dig up a lines reducer
23:52	justin_smith	or transducer
23:52	justin_smith	ahh, wait
23:52	justin_smith	75% faster with no change?