#clojure – 2015-02-22

2015-02-22

00:00	julianleviston	ddellacosta: yeah, it’s just creating a copy with bits missing, effectively… so should be roughly that.
00:00	justin_smith	ddellacosta: if you are removing n keys out of m, the into solution is N=(m-n), the select-keys solution is N=n
00:00	ddellacosta	I guess it's O(n) where n is the set of keys you are removing
00:00	ddellacosta	right
00:00	justin_smith	ddellacosta: so the number of keys being removed, and the initial count, are going to affect things a lot
00:00	julianleviston	now I have my beautiful function thanks guys… you really do rock… (defn filter-on-keys [pred coll] (select-keys m (filter pred (keys m))))
00:00	ddellacosta	right, right
00:01	julianleviston	haha coll !- m
00:01	julianleviston	good work justin_smith
00:01	julianleviston	I mean good work julianleviston
00:01	justin_smith	heh
00:08	tomjack	If I cared about performance I think I would write (fn [pred m] (reduce-kv (fn [m k v] (if (pred k) m (dissoc m k))) m m))
00:08	tomjack	,(time (let [m {:a "hey" :b "yes" "string-key" "should not include"} pred #(keyword? %)] (reduce-kv (fn [m k v] (if (pred k) m (dissoc m k))) m m)))
00:08	clojurebot	"Elapsed time: 1.471779 msecs"\n{:b "yes", :a "hey"}
00:09	justin_smith	ten times faster than the select-keys
00:09	tomjack	(for no good reason besides superstition)
00:09	justin_smith	*slower
00:09	ddellacosta	I'm not sure we can determine much from testing on such a small set of values
00:09	tomjack	right :)
00:09	justin_smith	that's true
00:10	tomjack	I guess the point of the reduce-kv is that you're seq-free
00:10	justin_smith	you've still got a seq on the last arg
00:10	tomjack	no
00:10	justin_smith	no?
00:10	clojurebot	no is tufflax: there was a question somewhere in there, the answer
00:10	ddellacosta	I would think the main thing is to reduce (ha) the number of linear scans over the same set of data
00:11	tomjack	well, I thought not
00:11	tomjack	but maybe you're right
00:12	justin_smith	tomjack: this seems relevant https://github.com/clojure/clojure/blob/96e8596cfdd29a2bb245d958683ee5fc1353b87a/src/clj/clojure/core/protocols.clj#L180
00:12	tomjack	PHM and PAM's kvreduce are seq-free
00:12	ddellacosta	what does having a seq vs. not do for you? Doesn't it still end up being the same amortized time?
00:12	tomjack	eh, not really
00:12	tomjack	I mean, not really seq-free I guess
00:12	tomjack	ddellacosta: oh, yeah, absolutely
00:12	julianleviston	is there a reject-keys? or should I just comp not my pred?
00:13	justin_smith	ddellacosta: the difference is you have lower constant cost
00:13	julianleviston	complement*
00:13	tomjack	but if that's all we cared about, we wouldn't have PHM at all, would we?
00:13	ddellacosta	justin_smith: sorry, can you explain? I'm not getting it
00:13	tomjack	:)
00:13	justin_smith	ddellacosta: same rationale as transducers - same time complexity, less time spent generating garbage
00:13	julianleviston	erm.. that was a silly question… is there a reject keys?
00:13	ddellacosta	justin_smith: dissoc ?
00:13	ddellacosta	er, sorry, that was for julianleviston
00:13	ddellacosta	see tomjack reduce above
00:14	ddellacosta	tomjack's *
00:14	julianleviston	ddellacosta: oh yeah, apply dissoc…stupid me!
00:14	tomjack	justin_smith: it looks like kvreduce for PHM ends up going through a NodeSeq in PersistentHashMap.java
00:14	ddellacosta	justin_smith: still not quite getting it
00:14	justin_smith	right, you need a linear view of the keys no matter what
00:14	tomjack	but looks to be less overhead than a normal seq, I think
00:14	julianleviston	apply makes me somewhat anxious...
00:14	tomjack	(anyway I think it hardly ever matters :))
00:14	ddellacosta	justin_smith: so it's about space considerations?
00:15	justin_smith	ddellacosta: two ops with the same time complexity can take a different amount of time due to overheads that are linear
00:15	justin_smith	it's about time constraints
00:16	tomjack	ddellacosta: binary trees often can get O(log_2(n)) operations. We get O(log_32(n)) stuff for our 32-ary trees. But O(log_2(n)) and O(log_32(n)) are the same -- O(log(n)) -- because log_2(n) = 5 * log_32(n)
00:16	justin_smith	reductio ad absurdum: consider an operations that takes 1 ms per element and is O(n) vs. an op that takes 1 year per input and is O(n)
00:16	justin_smith	ddellacosta: ^
00:16	tomjack	yet, for some reason, we still care about the difference
00:16	ddellacosta	tomjack, justin_smith, okay, I think it's getting through my thick skull now--thanks
00:17	justgreg	I was walking through this tutorial: http://clojure-doc.org/articles/tutorials/vim_fireplace.html and I can't get cpr to run properly even though I have classpath.vim in my pathogen .vim/bundle/ folder.
00:17	ddellacosta	justin_smith: did you mean constant above vs. linear though? "two ops with the same time complexity can take a different amount of time due to overheads that are linear"
00:17	justin_smith	ddellacosta: linear as in their cost is multiplied by the side of the input
00:18	justin_smith	rather than being constant for the algo regardless of input size
00:18	justgreg	I'm using vim in the terminal, executing from the correct path, with $lein repl running in a separate GNU screen terminal
00:18	justin_smith	justgreg: are you sucessfully connected then?
00:18	justgreg	justin_smith, no, that's exactly the problem.
00:20	justgreg	justin_smith, it was working, then I removed a line related to autocomplete from my .vimrc -- because autocomplete wasn't working properly.
00:20	justin_smith	OK - I don't know enough about fireplace to help beyond that, sorry. Thought maybe it was an issue where my clojure knowledge would help.
00:21	justin_smith	hopefully someone else knows more about fireplace and can help you out
00:21	justgreg	justin_smith, thanks anyway. #vim sent me here.
00:21	justin_smith	I find it odd that the tutorial does not mention any explicit "connect to a repl" step
00:22	justin_smith	I would think such a command would exist
00:22	justgreg	It mentions the :connect command, but it also ought to connect automatically.
00:23	justin_smith	I would try figuring out how to run connect manually
00:24	justgreg	(nod) I'm just annoyed because it was working previously, and pathogen.vim appears to be working erratically.
00:24	swarthy	When I was using vim 'Vundle' was a much simpler package manager
00:24	swarthy	I had vim + fireplace working with that
00:25	justgreg	swarthy, really? pathogen claims to just require putting everything in .vim/bundle
00:26	swarthy	Vundle you just add the github repo as a line, plus two other lines to your vimrc
00:26	swarthy	then when you start vim
00:26	swarthy	it does it all automatically
00:26	swarthy	to connect though
00:27	swarthy	just open two terms
00:27	swarthy	in one do $ lein repl
00:27	swarthy	look at the port number it shows
00:27	swarthy	then in the other term with vim
00:27	swarthy	do ':connect'
00:27	swarthy	follow the prompts using default for everything
00:27	swarthy	except port
00:27	swarthy	enter that from before
00:27	swarthy	Alternatively, if everything is working you just open vim in the directory where there is a running repl
00:28	swarthy	and a subsequent
00:28	swarthy	'.nrepl-port' file
00:28	swarthy	Not to start a flame war, but I've found emacs + prelude + evil-mode a better experience.
00:28	justgreg	run :connect as a vim command or enter it in the file?
00:28	swarthy	command
00:28	swarthy	it might be :Connect
00:28	swarthy	if that doesn't work
00:30	justgreg	I'm starting to get fed up w/ vim and liking lisps more and more. I might just try to deal w/ my c-ish scripting langauges in emacs rather than lisps in vim.
00:32	swarthy	justgreg: I had a hard time getting emacs going with evil mode on my own
00:32	swarthy	prelude makes it really easy to get up and running after being a vim user
00:32	swarthy	http://batsov.com/prelude/
00:32	swarthy	I recommend that, turning on evil mode is one line
00:32	swarthy	a lot of vim stuff works
00:33	swarthy	not 100% but enough
00:33	swarthy	I used vim for several years, but I'm not die hard about it.
00:34	swarthy	honestly I use vim for stuff still plenty, do the c stuff there. No reason to only use one thing, use whatever is best.
00:34	justgreg	I never learned it especially well. I treat it more or less like a nano with syntax highlighting and indenting. I've also never genuinely tried emacs outside of learning sml in it, which was how I learned basic fp.
00:34	julianleviston	prelude? haha I thought I was in the wrong channel there for a second :)
00:34	swarthy	oh like Prelude in haskell?
00:34	swarthy	might be where he got the name
00:35	julianleviston	swarthy: yeah :)
00:35	swarthy	justgreg: well prelude makes the barrier to entry basically 0. After two days I was flying around.
00:36	justgreg	Sweet. I was mostly looking for music-making in a language I could claim was making me a better programmer. There's a very good livecoding environment called Overtone.
00:36	swarthy	Yeah, I've seen it & I tried their emacs thing a while back. It was a bit complicated and I gave up.
00:36	swarthy	Might be easier now.
00:36	julianleviston	I really like stuff that bridges things. Clojure is very bridgy, obviously.
00:39	julianleviston	So I ended up with a “better” thing for selecting parts of a map… (defn select-filter [pred coll] (select-keys coll (keys (filter pred coll))))
00:39	justgreg	I was trying to use a scheme dialect, but it's not very well-maintained.
00:40	julianleviston	it makes things like this so much more readable: (let [expired-items (select-filter #(time-expired? (:timestamp %)) chan-maps)] …)
01:30	wenshan	I have two lists A: (1 2 3 4) and B (2 4 5 6), how do I do (- A B) to get (-1 -2 -1 -2)?
01:34	kriyative	wenshan: (map - '(1 2 3 4) '(2 4 5 6))
01:36	tomjack	(map - '(1 2 3 4) '(2 4 5 6) '(0 0 -1 0)) ? ;)
01:37	kriyative	ah, didn't see that ... I presume the second -1 was a typo?
01:48	wenshan	kriyative: yes, that was a typo, (map - A B) works, thank you
01:51	kriyative	wenshan: as tomjack indicated, `map` extends to (map - A B C ...) etc.
01:53	tomjack	,(apply map vector [[1 2 3] [4 5 6] [7 8 9]])
01:53	clojurebot	([1 4 7] [2 5 8] [3 6 9])
01:54	awwaiid	Question for any overtone folks who might be here: (apply eval ['(piano)]) works, but (apply-at (+ (now) 1000) eval ['(piano)]) does not; it appears to have some issue that it is silently discarding. Any pointers?
01:54	awwaiid	(note that the eval is because the '(piano) is actually dynamically generated)
02:28	wenshan	hmm, I have a single file (not within a project) opened and started a REPL with cider-jack-in. Now how can I use the math functions (e.g. round)? Simply evaluating (use 'clojure.contrib.generic.math-functions) returns "java.lang.ClassNotFoundException: clojure.contrib.generic.math-functions"
02:30	kriyative	wenshan: try (Math/round 3.14)
02:30	kriyative	I'm pretty sure clojure.contrib.generic.math-functions is deprecated
02:45	wenshan	kriyative: thanks again, (Math/round 3.14) works, but (Math/round (/ 1 20)) does not work, I guess this is because (/ 1 20) is a ratio, not a number?
02:48	TEttinger	wenshan: to import a file without being in a project, you would still need some amount of lein usage. I think lein imports some of its dependencies into the REPL by default, one of which lets you download a dep in the repl
02:48	TEttinger	pomegranate maybe?
02:48	TEttinger	aether?
02:48	TEttinger	I can't remember
03:06	rritoch	Is anyone here skilled with regular expressions?
03:06	amalloy	~anyone
03:06	clojurebot	anyone is anybody
03:09	rritoch	I wrote a blog/tutorial on reverse engineering regular expressions, and was hoping someone could review it to see if there is anything I've missed, or if there are any technical errors.
03:16	TEttinger	rritoch, post away
03:16	TEttinger	I like em, I wouldn't say I'm that skilled with them
03:16	rritoch	--> http://www.ritoch.net/2015/02/22/the-exorcism-of-regular-expressions/
03:16	TEttinger	wasn't someone making a regex prover or something?
03:17	rritoch	It is a little themed to sorcery, but other than that it should be fairly easy to read.
03:17	TEttinger	or a type checker for regexes?
03:18	rritoch	Hmm, I don't know. I made some code to ungreedy a regular expression using clojure, but I'm not aware of the projects your mentioning. This is more a manual process for reverse engineering a regular expression, though much of it can be automated.
03:19	rritoch	I'm also making the suggestion that programmers document their regular expressions, as if that would ever happen, lol
03:21	TEttinger	nice article, rritoch
03:21	TEttinger	I scanned the second page, didn't read in depth, but it's sound advice
03:22	rritoch	TEttinger: Thanks. I have to be honest, it took me 4 hours to write the blog and reverse engineer the example, but I think the end result is at least helpful.
03:22	amalloy	rritoch: are you really recommending documenting regexes by adding a commented-out verrsion with newlines and indentations, rather tahn recommending use of the /x flag?
03:23	rritoch	amalloy: No, that is just a middle step of the reverse engineering process
03:24	rritoch	amalloy: The final result is in the last code block.
03:24	TEttinger	ambrosebs might have been?
03:25	rritoch	amalloy: The final result is an approximation of BNF
03:27	TEttinger	rritoch: since such a big part of programming is giving names to things, the fact that regexes don't have much in the way of naming by default makes them hard to understand when they get large
03:27	TEttinger	I like your named component parser-style approach
03:33	rritoch	TEttinger: Well, the idea came to me while manually translating a BNF language definition into Java code. After translating enough entries it occured to me that the process was somewhat reversable, so this is what I came up with to extract the functionality of a complex regular expression.
04:29	the-kenny	Hm. Why is creating leiningen templates so painful? Copying all files over & then creating entries manually is cumbersome
04:33	rritoch	the-kenny: Leiningen is open source and can be extended with plugins. If your finding the process repetative you could probably make a plugin to automate the process. You would probably end up with a lot of users of the plugin.
04:44	the-kenny	rritoch: I know I know :/
05:09	julianleviston	the-kenny: or you could use that new thing instead of lein
05:09	the-kenny	julianleviston: doing that right now. It's still pretty cumbersome
05:09	julianleviston	the-kenny: what’s it called again?
05:09	the-kenny	newnew
05:09	julianleviston	the-kenny: why’s it cumbersome?
05:09	the-kenny	oh no, wait
05:10	the-kenny	it's [lein-create-template "0.1.1"]
05:10	the-kenny	julianleviston: still many manual steps. Cleaning up, etc. It creates a flat folder structure in resources/leiningen/new/ which is confusing in some situations.
05:10	julianleviston	the-kenny: I was talking about Boot
05:10	the-kenny	oh
05:11	julianleviston	the-kenny: sozzy :)
05:11	the-kenny	actually I'd like to be able to just specify a "normal" leiningen project as source and rename the namespaces. Like forking a git repository
05:12	julianleviston	the-kenny: make it so, captain :)
05:12	the-kenny	haha :)
05:43	wenshan	b
08:48	AeroNotix	Can anyone recommend a websocket library for ClojureScript? The one that appears the most is Sente, but my god is it bloody complex
08:49	dnolen	AeroNotix: Google Closure Library has some stuff you can use if you want something more minimal.
08:50	AeroNotix	dnolen: all I really need is something that returns perhaps channel and has no huge opinions on what the message format should be
08:50	AeroNotix	https://github.com/james-henderson/chord seems reasonable at first glance.
08:51	AeroNotix	dnolen: if I were to use the google library, I wonder how easily I can map the JS docs into Cljs. Is that something you think is a barrier?
08:52	AeroNotix	(or perhaps some enterprisin' individual has converted the docs, I wouldn't be surprised)
08:52	dnolen	AeroNotix: the docs haven't been converted but there's really no need, CLJS interop is pretty simple after all.
08:53	AeroNotix	dnolen: I'm not really familiar with javascript at all tbh
08:53	dnolen	AeroNotix: it will be difficult to be as productive as possible with ClojureScript if you don't know JavaScript basic.
08:53	dnolen	s/basic/basics
08:53	AeroNotix	I know the basics-ish
08:53	AeroNotix	lets say
08:54	dnolen	AeroNotix: then you probably won't have a problem
08:54	AeroNotix	cool, I'll persevere
08:54	justin_smith	AeroNotix: dude wrote the lang in a week, you shouldn't take long to get up to speed
08:55	AeroNotix	lol
08:55	AeroNotix	https://github.com/swannodette/om-async-tut oh this is nice
10:32	sol__	what does it mean if i have ^bytes in the signature? (defn foo [x ^bytes payload])?
10:33	sol__	oh, java type hints :)
10:36	frzn	oskarth: is breakfast running live anywhere? Couldn't see it running in http://breakfast.clojurecup.com/
10:40	AeroNotix	frzn: what the hell is that webpage haha :)
10:41	frzn	AeroNotix: no idea! haha. But the oskarth project looks nice. I'm planning to use it, if I can get it to work.
11:10	gfredericks	happy 10:10am to everybody in my time zone
11:12	devll	it is 10:00 pm here,but Happy to you too.
11:12	gfredericks	must be one of those weird off-by-ten-minutes time zones
11:13	devll	lol. 10:12
11:13	devll	Any recommendations for scheduling libraries?
11:14	gfredericks	~this one weird time zone \|will destroy\| your faith in humanity; programmers hate it!
11:14	clojurebot	c'est bon!
11:14	devll	quartzite , at-at
11:15	devll	I am not sure which to pick.
11:17	frzn	AeroNotix: #clojurecup-breakfast
11:17	frzn	now is running nice :)
11:17	frzn	(local)
11:17	frzn	oskarth: nice job.
11:59	irctc__	I don't know if it's okay to ask here but quick question guys: why does (for [a (range 4), b (range a)] [a b]) give the same result as (for [a (range 1 4), b (range a)] [a b]) even though `a` should be starting from 0? It's giving me ([1 0] [2 0] [2 1] [3 0] [3 1] [3 2]) as the result. And I'm expecting it to start from [0 0].
12:01	aroemers	devll: Depends on your usecase. I find at-at nice and simple. Quartzite has more features.
12:05	vas_	,(for [a (range 1 4)] [a])
12:05	clojurebot	([1] [2] [3])
12:06	vas_	,(for [a (range 4)] [a])
12:06	clojurebot	([0] [1] [2] [3])
12:06	subhashgo	irctc__ : (range 0) -> ()
12:07	irctc__	,(for [a (range 4) b (range a)] [a b])
12:07	clojurebot	([1 0] [2 0] [2 1] [3 0] [3 1] ...)
12:08	irctc__	oh
12:08	irctc__	subhashgo: ok thanks, it just hit me.
12:08	subhashgo	No worries
12:08	irctc__	:)
12:13	vas_	irctc_: i think this is an appropriate place to ask that stuff, by the way, as it always helps me out when i try and provide an answer, so everyone wins :]
12:17	irctc__	vas_: that's good to know :) thanks for helping out too
12:38	kras	Hi, why is this code hanging http://pastebin.com/yru9TzKx
12:38	kras	I am just trying out a basic loop recur
12:39	kras	Any hints will really help
12:41	hyPiRion	,(next '(1))
12:41	clojurebot	nil
12:41	raek	kras: use 'empty?' instead of 'nil?', and use 'conj' instead of 'concat'
12:42	raek	or, instead of changin the 'nil?', you could change the let to [e (seq v), res []]
12:43	hyPiRion	kras: what does (next v) return? :)
12:44	kras	,(next [1 2 3 4 5
12:44	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading>
12:45	kras	,(next [1 2 3 4 5])
12:45	clojurebot	(2 3 4 5)
12:45	hyPiRion	kras: Eventually, a better hint: What's the difference between (next v) and (next e)?
12:45	raek	kras: the propblem using 'concat' here is that it expects to sequences, but you are giving it a vector and an element
12:45	kras	:-\|
12:45	kras	Got it thanks hyPiRion
12:46	hyPiRion	np, was confused for a bit too
12:46	kras	I should be using the binded e inside the loop
12:46	kras	raek: thanks for the suggestions
12:50	kras	raek: concat works on two colls, whereas I am giving it one coll and one Long, so had to change it to conj
12:55	kras	what is an idiomatic way of checking an element's presence in a collection? Equivalent of "in" operator in python
12:57	kras	,(some #{2] [1 2 3 4])
12:57	clojurebot	#<RuntimeException java.lang.RuntimeException: Unmatched delimiter: ]>
12:57	kras	,(some #{2} [1 2 3 4])
12:57	clojurebot	2
12:57	kras	this seems like an overkill
13:00	the-kenny	kras: yes, that's the idiomatic way
13:00	the-kenny	If your collection is a set, you can use contains?
13:07	oskarth	frzn: thanks! It's currently not running live (the free server clojurecup offered expired afaik)
13:07	oskarth	frzn: curious, how did you find it?
13:08	frzn	oskarth: I found one project from clojurecup in hackernews, looked for others and found yours.
13:08	oskarth	oh cool
13:09	oskarth	hope it's useful!
13:09	oskarth	meant to extend it and clean it up, but never happened :p
13:09	frzn	I'm planning to create a integrated chat with IRC to put in a sidebar in my webapp.
13:09	frzn	oskarth: I now how it is! haha
13:09	frzn	but it will be useful, for sure.
13:10	oskarth	awesome :)
13:10	imanc_	what's the best way to write gui apps in clojure?
13:32	justin_smith	imanc_ seesaw makes it pretty easy, people like the way javafx looks though
14:15	vas_	what's a good approach for caching database results between queries?
14:19	justin_smith	vas_: I've used a wrapper where an atom maps from queries to results, and insertions remove keys from the hash (so you don't get stale results)
14:20	justin_smith	vas_: also, eg. datomic is cached for you automatically
14:24	gfredericks	anybody know why clojure seems to name its functions one package level up?
14:25	gfredericks	e.g. (ns foo.bar) (defn baz []) creates the class foo.bar$baz
14:25	vas_	justin_smith: well i have not used atoms before, so i will have some researching to do ... I was trying to naievely just memoize the function that connects to the DB, but I can't invoke "nth" on the result set .. dunno why
14:25	justin_smith	vas_: atoms are pretty straightforward, it's worth taking a few hours to figure them out
14:26	justin_smith	,(let [a (atom {}] (swap! a assoc :a 0) (swap! a assoc :b 1))
14:26	clojurebot	#<RuntimeException java.lang.RuntimeException: Unmatched delimiter: ]>
14:26	justin_smith	er
14:26	justin_smith	,(let [a (atom {})] (swap! a assoc :a 0) (swap! a assoc :b 1))
14:26	clojurebot	{:b 1, :a 0}
14:28	vas_	justin_smith: cool. arigato
14:30	vas_	by the way, some things just clicked for me the other day with enlive. was able to clean up my code immensely
14:30	justin_smith	vas_: for what you want atom / swap! (with assoc or dissoc) / @ should be all you need
14:30	justin_smith	cool
14:30	vas_	@?
14:30	clojurebot	@ is like the macro version of apply
14:30	vas_	lol thank you clojurebot! =D
14:31	justin_smith	,(let [a (atom "hello")] [a @a])
14:31	clojurebot	[#<Atom@267038a5: "hello"> "hello"]
14:31	justin_smith	notice the difference between the two elements of that vector
14:31	justin_smith	that's what @ does
14:31	justin_smith	it's a reader shortcut for deref
14:49	gfredericks	oh clojurebot was trying to talk about ~@
14:50	justin_smith	oh, that makes much more sense, yeah
14:50	justin_smith	~@?
14:50	clojurebot	@ is forget @
14:50	justin_smith	hahaha
14:52	justin_smith	~~@?
14:52	clojurebot	~@ is splicing unquote
14:52	justin_smith	there we go
14:53	kaplan_	justin_smith, what is difference between unquote and splicing unquote?
14:53	justin_smith	,`(a b ~(+ 1 2 3))
14:53	clojurebot	(sandbox/a sandbox/b 6)
14:54	justin_smith	,`(a b ~@(+ 1 2 3))
14:54	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: Don't know how to create ISeq from: java.lang.Long>
14:54	justin_smith	err
14:54	justin_smith	,`(a b ~@[1 2 3])
14:54	clojurebot	(sandbox/a sandbox/b 1 2 3)
14:54	justin_smith	,`(a b ~[1 2 3])
14:54	clojurebot	(sandbox/a sandbox/b [1 2 3])
14:54	justin_smith	it splices
14:55	kaplan_	justin_smith, that went over my head
14:57	justin_smith	~ unquotes
14:57	clojurebot	Pardon?
14:57	justin_smith	~@ inserts a collection, unquoted
14:57	clojurebot	Cool story bro.
14:58	justin_smith	I think I have a clearer way to show it
14:58	justin_smith	,(def a 42)
14:58	clojurebot	#'sandbox/a
14:58	justin_smith	,`(a ~a)
14:58	clojurebot	(sandbox/a 42)
14:58	justin_smith	see how ~ made it unquote?
14:59	justin_smith	,`(a ~[a a a])
14:59	clojurebot	(sandbox/a [42 42 42])
14:59	kaplan_	justin_smith, ah, I see
14:59	justin_smith	,`(a ~@[a a a])
14:59	clojurebot	(sandbox/a 42 42 42)
14:59	justin_smith	notice the differencebetween what ~[] did and what ~@[] did
14:59	kaplan_	yep
14:59	kaplan_	no vector around ~@
14:59	justin_smith	right, it gets spliced in to the parent
15:00	kaplan_	justin_smith, can you give a practical example of a macro?
15:01	justin_smith	,(defmacro spy [form] `[~'form ~form])
15:01	clojurebot	#'sandbox/spy
15:01	justin_smith	,(spy a)
15:01	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: form in this context, compiling:(NO_SOURCE_PATH:0:0)>
15:01	justin_smith	hrm
15:02	justin_smith	right
15:02	justin_smith	,(defmacro spy [form] `['~form ~form])
15:02	clojurebot	#'sandbox/spy
15:02	justin_smith	,(spy a)
15:02	clojurebot	[a 42]
15:02	justin_smith	,(spy (+ 1 2))
15:02	clojurebot	[(+ 1 2) 3]
15:03	justin_smith	the macro returns a vector containing the original input quoted, and what it evaluates to
15:03	kaplan_	justin_smith, ah, I see
15:04	justin_smith	the general idea with a macro, is you return the form that should be evaluated
15:04	kaplan_	justin_smith, but I still can't think of anything where I might find this useful
15:04	justin_smith	def is a macro
15:04	benmoss	is there a decent way to access the version number of a lib from within the lib itself
15:04	justin_smith	that's why you can just give the name you are defining, and don't have to quote it or anything
15:04	kaplan_	justin_smith, ah, I see
15:05	justin_smith	kaplan_: in general, you should rarely need to write macros. But they are very useful when you need them.
15:05	justin_smith	they are for when you need to change the evaluation rules, or introduce a new syntax
15:07	justin_smith	"the first rule of macro club, is don't write macros"
15:07	kaplan_	justin_smith, are all of clojure's built in keywords like def built with macros?
15:07	justin_smith	kaplan_: there are a lot of macros in the language
15:07	justin_smith	actually, it's possible to build a list
15:08	justin_smith	,(filter (comp :macro meta) (vals (ns-publics 'clojure.core)))
15:08	clojurebot	(#'clojure.core/when-first #'clojure.core/cond->> #'clojure.core/gen-class #'clojure.core/while #'clojure.core/import ...)
15:08	justin_smith	in your repl, that will list all the things in clojure.core that are macros
15:08	justin_smith	&(filter (comp :macro meta) (vals (ns-publics 'clojure.core)))
15:08	lazybot	java.lang.SecurityException: You tripped the alarm! ns-publics is bad!
15:09	justin_smith	blergh
15:18	crazydiamond	Hi. In CIDER, when cider-error buffer displayed, can I automatically jump to line/char where error happened?
16:05	devll	Hi,in mf Compojure appindex.htm is a valid url. I want to trim "index.htm/".
16:05	devll	*my
16:07	devll	but Compujure treats "index.htm" and "index.htm/" the same way
16:07	devll	It never reaches my wrapper function.
16:09	devll	I can manage to trim urls like "/music/" to "/music",but not the "htm" files.
16:09	devll	How can I trim this?
16:12	justin_smith	why is it not reaching your wrapper?
16:15	devll	none of the static resources reach wrappers.
16:16	devll	I think "index.htm/" is treated as static.
16:16	justin_smith	oh, because your middleware is shortcircuiting the request
16:17	justin_smith	yeah, having a route that should be the same as a static resource is a bad idea, you should move one of the two
16:18	justin_smith	why does the file "index.htm" need to be in the static resources folder?
16:18	devll	it is in the public folder.
16:18	justin_smith	why?
16:18	clojurebot	http://clojure.org/rationale
16:19	AeroNotix	~why
16:19	clojurebot	http://clojure.org/rationale
16:19	AeroNotix	,why
16:19	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: why in this context, compiling:(NO_SOURCE_PATH:0:0)>
16:19	AeroNotix	THERE IS NO WHY
16:19	AeroNotix	:)
16:19	justin_smith	devll: if you want something to be a route with a handler etc. then it shouldn't be a static resource, and visa versa
16:19	devll	I am just serving the file.
16:19	justin_smith	because one of the two is not going to work if you try to use both
16:20	devll	"index.htm" is not a route
16:20	AeroNotix	so you have a static file handler/middleware?
16:20	AeroNotix	and you have a 'chop-off-the-trailing-slash-middleware'
16:20	AeroNotix	?
16:20	AeroNotix	show your routing code.
16:20	devll	I dont have static file mw
16:21	justin_smith	devll: sorry, I misunderstood. In this case you need to switch the ordering of the static wrapping mw and the drop-slashes one
16:21	AeroNotix	justin_smith: yeah^ Was thinking this was the case.
16:21	justin_smith	devll: if the file is getting served, you do, it is likely hidden in the default ring middleware
16:21	devll	(route/resources "/")
16:21	devll	(ANY "*" []
16:21	devll	"404"))
16:22	devll	and I have many route like "/music"...
16:22	devll	OK
16:23	justin_smith	OK, so you explicitly serve resources
16:23	justin_smith	and you want to remove trailing slashes before that gets hit?
16:23	devll	yes.
16:24	justin_smith	do you have a middleware that does this already?
16:24	devll	I have one chops trailing slashes
16:24	devll	It does the jobs for "/music/"
16:25	justin_smith	but you still get a 404 for /index.htm/
16:26	devll	in my case ,it is a file download
16:26	devll	I guess I should add a static mw and reorder it.
16:26	devll	am I right?
16:26	justin_smith	that sounds right, yes
16:27	devll	OK. thanks. (inc justin_smith)
16:28	devll	(inc justin_smith)
16:28	lazybot	⇒ 192
18:42	chr15m	Hello! I have been beating my head against the externs file requirement of Google's closure for days. I finally found this project, which fixed all of my problems by generating an externs file from my cljs code directly: https://github.com/ejlo/lein-externs - how come it only has two stars? Has everybody moved on from this? What do people use to handle the externs file situation?
20:06	JavaDog	Could anyone give me a quick hand? I'm doing this for a code gold thing:
20:06	JavaDog	golf*
20:06	JavaDog	(drop iterator (remove #(.contains (take-nth (nth collection iterator) collection) %) collection)))
20:07	JavaDog	However, I get a "java.lang.IndexOutOfBoundsException: null" on this line. I think it's related to lazy sequences, and I've tried using (doall thatSeq), but I'm not sure whether I'm doing that right.
20:17	irctc__	is there an atom? equivalent in clojure
20:34	gfredericks	nope
20:34	gfredericks	,clojure.lang.IAtom
20:34	clojurebot	clojure.lang.IAtom
20:34	gfredericks	can check against that
20:35	gfredericks	there's a ticket somewhere about this I think
20:35	gfredericks	,atom?
20:35	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: atom? in this context, compiling:(NO_SOURCE_PATH:0:0)>
20:35	cfleming	gfredericks: Yeah, IIRC it might be for 1.7
20:39	gfredericks	,clojure-version
20:39	clojurebot	{:interim true, :major 1, :minor 7, :incremental 0, :qualifier "master"}
20:39	crazydiamond	Hi. Is there ability to define functions like = for certain classes created with deftype?
20:42	gfredericks	I think overriding Object#equals will accomplish that
20:42	gfredericks	not sure what other functions are "like =" that you're referring to
20:43	amalloy	gfredericks: people who ask for an atom? equivalent usually mean it in the common lisp sense
20:44	crazydiamond	I'mhaving code like this: (deftype MyType [...] ...) (MyType. x [...]) (MyType. y [...]) (are_equal x y)
20:44	crazydiamond	and there I have almost everything in class definitions
20:44	crazydiamond	but standalone function are_equal
20:45	crazydiamond	and I want it to be associated with types
20:45	crazydiamond	though, everything works
20:45	crazydiamond	but I still think it would be better to do association
20:47	gfredericks	amalloy: oh that sense of "equivalent"
20:58	amalloy	gfredericks: i'm curious what other sense of equivalent you're thinking of
21:00	TEttinger	,atom?
21:00	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: atom? in this context, compiling:(NO_SOURCE_PATH:0:0)>
21:00	TEttinger	,promise?
21:00	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: promise? in this context, compiling:(NO_SOURCE_PATH:0:0)>
21:00	TEttinger	hm
21:00	TEttinger	,ref?
21:00	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: ref? in this context, compiling:(NO_SOURCE_PATH:0:0)>
21:00	TEttinger	are there any type checks for stuff like atoms?
21:01	gfredericks	amalloy: "equivalent to this thing from another language that actually exists" vs "equivalent to this imaginary clojure function"
21:01	gfredericks	TEttinger: what's a "type check"? you mean a function like the ones you're searching for?
21:01	gfredericks	,(->> (ns-publics 'clojure.core) keys (filter #(= \? (last (str %)))) shuffle)
21:01	clojurebot	[nil? fn? var? thread-bound? ifn? ...]
21:02	TEttinger	I guess, kinda like float? or something like it
21:02	gfredericks	,(->> (ns-publics 'clojure.core) keys (filter #(= \? (last (str %)))) shuffle)
21:02	TEttinger	,float?
21:02	clojurebot	#<core$float_QMARK_ clojure.core$float_QMARK_@3ee8c23e>
21:02	clojurebot	[future-done? odd? future? bound? zero? ...]
21:02	gfredericks	,(->> (ns-publics 'clojure.core) keys (filter #(= \? (last (str %)))) shuffle)
21:02	clojurebot	[pos? identical? every? future-cancelled? ifn? ...]
21:02	TEttinger	whatcha doing gfredericks?
21:03	TEttinger	imaginary clojure, from the makers of invisible bike and high-performance INTERCAL
21:04	TEttinger	&(->> (ns-publics 'clojure.core) keys (filter #(= \? (last (str %)))))
21:04	lazybot	java.lang.SecurityException: You tripped the alarm! ns-publics is bad!
21:04	TEttinger	haha
21:05	TEttinger	,(->> (ns-publics 'clojure.core) keys (filter #(= \? (last (str %)))) #(clojure.string/join " "))
21:05	clojurebot	#<sandbox$eval195$fn__196 sandbox$eval195$fn__196@5cdc4aaa>
21:05	TEttinger	,(->> (ns-publics 'clojure.core) keys (filter #(= \? (last (str %)))) (clojure.string/join " "))
21:05	clojurebot	"decimal? contains? every? satisfies? seq? fn? vector? thread-bound? isa? char? some? future-done? pos? sequential? neg? reduced? float? set? reversible? bound? map? volatile? var? empty? string? associative? keyword? even? extends? counted? future? zero? not-every? class? future-cancelled? sorted? nil? instance? record? identical? true? integer? special-symbol? ratio? delay? ifn? chunked-seq? dis...
21:05	TEttinger	so we have var?
21:06	TEttinger	and delay?
21:06	TEttinger	very odd
21:07	gfredericks	there's a ticket for it
21:16	gfredericks	,(defmacro defmulti! [name & args] `(do (def ~name nil) (defmulti ~name ~@args)))
21:16	clojurebot	#'sandbox/defmulti!
21:20	TEttinger	gfredericks, what... I'm slightly nervous to use that
21:22	rhg135	what is the point of this defmulti! i wonder
21:22	gfredericks	TEttinger: defmulti refuses to redefine things the second time you use it; defmulti! tricks it into doing so
21:22	rhg135	ah i see
21:23	TEttinger	that's... devious
21:23	gfredericks	also racey since the function is temporarily nil
21:24	rhg135	i don't think it's racey since do is guaranteed to run them in order
21:25	gfredericks	another thread could call it while it's nil
21:26	gfredericks	I bet you could fix that by setting it to a proxy function instead
21:28	rhg135	oh I see
21:30	gfredericks	amalloy: oh I just figured out how to throw that dynamic var exceptoin
21:31	gfredericks	it looks like it is only possible with futures and agents
21:32	amalloy	binding conveyance? i sorta expected that to prevent it, not cause it, but okay
21:32	gfredericks	TIL that what futures and agents do is different from what bound-fn does
21:32	gfredericks	which is different from what starting a raw thread does, which was your original suggestion
21:33	gfredericks	dynamic vars what are you gonna do.
21:35	crazydiamond	Hi. Is there a way to clean session in REPL? I'm using fireplace.vim and doing series of updates followed by %Eval. So, next time I hit eval, old things that I might deleted are still alive. Is there a way to start clean, each time I'm doing %Eval? (This effect makes Clojure sooo stateful for me).
21:43	justin_smith	crazydiamond: clojure.tools.namespace has a namespace recet
21:43	justin_smith	*reset
21:43	crazydiamond	justin_smith, thanks
21:44	crazydiamond	(clojure.tools.namespace.repl/refresh) works for me now
21:44	TEttinger	(inc justin_smith)
21:44	lazybot	⇒ 193
21:44	TEttinger	almost to 200
21:44	justin_smith	there is also stuartsierra's component for doing modular restarting of state
21:44	justin_smith	getting close
21:48	gfredericks	is tonight the night that justin_smith gets to 200?
21:48	gfredericks	justin_smith: quick start telling jokes
21:49	justin_smith	I've been lambda lifting all night, and boy are my arms tired!
21:49	rhg135	crickets
21:50	gfredericks	tonight is not going to be the night
21:53	justin_smith	My wife, lemme tell ya folks, I try to explain to her, Liskov's substitution principle says I could just trade her in for a mentally disabled donkey...
21:56	gfredericks	a mentally disabled monkey is a subtype of your wife?
21:56	justin_smith	it's quite unfortunate
21:57	justin_smith	(not even dating not to mention married)
21:57	rhg135	ok...
21:57	justin_smith	sorry, I will stop making intentionally cringeworthy CS themed jokes
21:58	justin_smith	it was my "best" interpretation of henny youngman groaners
21:58	justin_smith	https://www.youtube.com/watch?v=i7gg8GGP79w
22:05	gfredericks	I listened to that entire thing and now I'm older
22:06	justin_smith	hehe
22:07	chr15m	does anyone else find this passive aggressive:
22:07	chr15m	$ git rebase --continue
22:07	chr15m	No rebase in progress?
22:08	chr15m	maybe i just need more sleep