#clojure – 2013-12-15

2013-12-15

00:00	andyf_	rovar: I have often defined a function map-vals defined as (into {} (for [[k v] my-map] [k (f v)])) where my-map and f are args.
00:01	andyf_	another short way is (zipmap (keys my-map) (map f (vals my-map)))
00:01	rovar	ooh
00:01	rovar	zipmap
00:02	rovar	me likey
00:02	rovar	very haskellish
00:02	rovar	my existing implementation was the into.. for comprehension
00:02	rovar	I just figured such an operation is common, and would have a clever combinator..
00:04	andyf_	It is reasonably common, but there is nothing in the core library for it. I think flatland/useful might define the into/for version for map-vals, map-keys, and map-keyvals IIRC
00:04	rovar	someone on stackoverflow had one using reduce, which might do well for large values of m
00:06	andyf_	The into version uses transients, so I would guess it would be faster than the zipmap version, which doesn't use transients, for large maps.
00:11	coventry	andrei: You can do something like htis, though. https://www.refheap.com/21941
00:12	rovar	andyf_, ya.. constructing two new lists to make a 3rd new list is most definitely slow.
00:14	andrei	coventry: Thanks!
00:21	seangrove	technomancy: Any thoughts on improving the `heroku run lein repl` experience? Or do you recommend live-repls to the running app instead?
00:24	rukor	interesting situation with clojurescript. when i have a macro in the project sources, lein cljsbuild takes 18s to compile the first time and 9s for each subsequent compilation. If i move the macro file to a library or project inside checkouts, initial compile time returns to 8s with subsequent compile times in subsecond. Is this expected?
00:26	dsrx	,(doc zipmap)
00:26	clojurebot	"([keys vals]); Returns a map with the keys mapped to the corresponding vals."
00:30	murtaza52	needed help on core.async
00:31	murtaza52	I wanted to broadcast a msg on two different channels, how do I do that ?
00:32	bbloom	murtaza52: you can just write in to two different channels, unless you really need it to appear "simultaneous"
00:32	bbloom	murtaza52: but there is also some new stuff: https://github.com/clojure/core.async/blob/master/src/main/clojure/clojure/core/async.clj#L635
00:33	bbloom	murtaza52: i'd be cautions however, you probably don't need that
00:33	murtaza52	I have a program which receives some input from http, these have to be then processed by two different fns independently
00:33	murtaza52	so I wanted to relay the data to the 2 diff fns, and then get it back
00:33	rovar	murtaza52, sounds like a job for mult
00:34	rovar	what do you mean get it back, exactly?
00:34	coventry	Is mult preferred to broadcast in core.async.lab? http://clojure.github.io/core.async/#clojure.core.async.lab/broadcast
00:34	murtaza52	I mean after the data is processed, send it back on another channel, where the main thread of the program is listening
00:34	rovar	murtaza52, this is the best examples I've found for async so far : https://github.com/halgari/clojure-conj-2013-core.async-examples/blob/master/src/clojure_conj_talk/core.clj
00:35	rovar	so if your functions are passed in and out channels, and the in channels have 'tap'ped into a mult, the you're good to go
00:36	rovar	broadcast is very sweet, but if you don't need arbitrary topics, it might be overkill
00:36	rovar	pub/sub against topics, instead of just tapping into channels..
00:37	rovar	if you want to get crazy, you can even 'mix' the two output channels from your functions
00:37	rovar	into a single channel
00:39	murtaza52	rovar: thanks
00:40	murtaza52	currently my fns only take a coll, however now I will create a higher order one which will also take in and out channels, isnt this complecting things ?
00:40	murtaza52	how do u separate out the concerns
00:46	alew	is there a good way to test lein plugins that use eval-in-project?
01:39	logic_prog_	does clojurescript have something like refer-clojure :exclude ?
01:48	tony	a
02:32	dnolen	logic_prog_: yes
02:33	dnolen	bbloom: todomvc in cljs is awesome
03:58	andrei	How can I get the version number of a loaded library in the repl?
03:58	justin_smith	andrei: I don't know that that is possible
03:59	justin_smith	lein classpath will show you the jar versions that would be pulled in
04:00	andrei	justin_smith: Ah. So version numbers are just in the filenames and are not recorded in the jars themselves?
04:01	justin_smith	they are in the project.clj
04:01	andrei	I have a library with a function that isn't public, but I'd like to expose it anyway. Is there a way to mark it as public?
04:01	justin_smith	the classpath reveals it via the path to the jar
04:01	andrei	justin_smith: Yup, I understand. But if it was recorded in the jar it should be available somehow
04:01	justin_smith	problem is project.clj has the same name
04:01	justin_smith	in every resource
04:02	justin_smith	how would you find the right one?
04:02	justin_smith	most projects don't define the version outside that (or the pom.xml that is generated from it)
04:03	andrei	justin_smith: Ah, oh well. Thanks!
04:04	andrei	justin_smith: And clojure doesn't read in the pom.xml file?
04:04	justin_smith	it does
04:04	justin_smith	but it uses it for resolving the dep
04:04	andrei	justin_smith: And then discards it?
04:04	justin_smith	it is not stored in the namespaces of the project anywhere
04:04	justin_smith	not that I know of
04:04	andrei	justin_smith: Oh ok. That's kinda strange. Seems like useful information to have around
04:05	justin_smith	regarding the private fn (in-ns 'other-ns) (def now-public private-fn) ; now "now-public" can be called from anywhere
04:06	justin_smith	also you could alter the var metadata and set :private false I think, but I find the above easier
04:06	andrei	justin_smith: Ah, awesome. Thanks!
04:17	Alfred	Can someone explain why " (iterate #(rand-int %) 10) " produces result sequence like this: " (10 8 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ...) "?
04:19	progo	Alfred: rand-int is right-exclusive so the seq is bound to converge at some point
04:19	progo	(rand-int 10) produces numbers from 0 to 9. The next application will be atmost (rand-int 9) that produces numbers from 0 to 8. And so on.
04:21	Alfred	thank you for your explanation, any solution to this problem?
04:21	progo	Alfred: do you want a steady stream of random numbers? Try 'repeatedly'
04:23	Alfred	yes, steady series of random. but does 'repeatedly' behaves differently from 'iterate'?
04:24	progo	'iterate' reuses the result of the last function call to the next iteration. 'Repeatedly' is more for side-effects and so
04:25	Alfred	bingo. you bring up an important point of 'iterate' which i missed, thank you very much!
04:25	progo	ie. (iterate f 0) => (0 (f 0) (f (f 0)) ...); while (repeatedly f) = ((f) (f) (f) ...)
04:26	progo	you're welcome.
04:49	markusXY	Hi, what is the recommended way to output an xml file which i modified with clojure.xml and clojure.zip? clojure.xml/emit seems to be discouraged and i am getting a npe. Does clojure.data.xml have a function that takes the same datastructure?
04:49	noprompt	bitemyapp: ah! i'm having a good time with this! wee!
04:50	noprompt	bitemyapp: i guess i just couldn't appreciate it before.
04:59	bitemyapp	noprompt: :D
05:00	noprompt	bitemyapp: the only thing that's been irritating is some minor things about haskell mode.
05:01	bitemyapp	noprompt: highly fixable, keep an eye on chris done's github
05:14	markusXY	I guess i'll just rewrite my code to fit it to clojure.xml.data.
09:27	ddellacosta	why is the second argument to subvec exclusive?
09:28	ddellacosta	any particular reason? Seems counter-intuitive to me
09:28	opqdonut	because half-open intervals make sense
09:28	opqdonut	a) if it were inclusive, you couldn't have an empty subvec (without using e.g. -1 as the pair for 0)
09:29	opqdonut	b) (subvec v start (+ start len)) is pretty elegant
09:29	opqdonut	c) see also http://www.cs.utexas.edu/users/EWD/transcriptions/EWD08xx/EWD831.html
09:30	progo	good stuff.
09:30	ddellacosta	opqdonut: checking out that link now, thanks
09:30	ddellacosta	opqdonut: re: a, sorry I don't get it--what do you mean an empty subvec? Like, (subvec v 4) or something?
09:31	opqdonut	ddellacosta: like (subvec v 0 0) will give you []
09:32	progo	and that's rather elegant for some of the recursive applications.
09:32	opqdonut	yeah, it's a useful corner case often
09:33	opqdonut	you don't have to treat the empty case specially
09:33	ddellacosta	opqdonut: okay, that is helpful, thank you! #clojure is full of awesome, as usual...
09:48	danielszmulewicz	howy
09:48	danielszmulewicz	howdy
10:38	edw	Anyone (else) having cider blow up on them with a stack overflow when you try to eval `ns` forms in a file?
10:46	luxbock	is there a way to call an anonymous function from inside of itself?
10:47	justin_smith	luxbock: (fn named [n] (named (dec n)))
10:47	justin_smith	that of course will go infinitely, but you get the idea
10:47	luxbock	ah great
10:47	luxbock	how did I not think to try that
10:48	justin_smith	the extra name arg is not intuitive, I found it in some docs at some point
10:50	luxbock	also wanted to ask if doing stuff like this is considered bad style: https://gist.github.com/7974531
10:50	luxbock	the (eval `(mget ~@indices)) part
10:51	Bronsa	luxbock: that's (apply mget indices)
10:52	pdk	anything involving eval is bad style
10:52	luxbock	ah right
10:52	luxbock	durr
10:52	Bronsa	assuming mget is a function and not a macro
10:52	luxbock	yep, it is
10:58	pepijndevos	how do I convert a js datastructure to cljs?
11:00	luxbock	https://gist.github.com/luxbock/6d8250cdc12b9eb27567
11:00	brainproxy	pepijndevos: tried js->clj ?
11:00	luxbock	does this happen because I gave the anonymous function a name? how would I fix this?
11:01	pepijndevos	brainproxy, yes. gives nil
11:02	pepijndevos	oh durr... string keys
11:04	brainproxy	yeah, I've made that mistake too
11:04	justin_smith	luxbock: keyword application does not work that way
11:05	justin_smith	(:utility-fn pd [:confess :confess]) says look for :utility-fn and return [:confess :confess] if not found
11:05	justin_smith	you want ((:utility-fn pd) [:confess :confess])
11:06	justin_smith	,(:a {} :b) ; viz
11:06	clojurebot	:b
11:06	justin_smith	,(:a {:a 0} :b)
11:06	clojurebot	0
11:06	luxbock	ah right, thanks
11:35	supersym	anyone got experience with the googl api client libraries? whats the deal with them, since they aren't hosted on maven or anything... can I just include this with my app for redeployment? And if so, how do I ensure they are picked up by leiningen? Do I just do a mvn local install and its good or?
11:36	seangrove	supersym: They're not especially nice
11:37	jonasen	Bronsa: andyf: experimenting with ast-indexing in eastwood https://github.com/jonase/eastwood/compare/indexing
11:37	seangrove	supersym: They're on maven though, you'll need something like https://www.refheap.com/ea915eb226642598ecfeb5ab9 in your lein dependencies
11:37	jonasen	Bronsa: andyf: It's a port of an old project of mine (https://github.com/jonase/scape)
11:38	supersym	seangrove: thank you... I figured about as much (that they weren't friendly and all... ^^)
11:54	Bronsa	jonasen: uuh nice!
11:59	adomokos	#clojure
12:07	instilled	anyone knows how to exclude ns from being read with 'lein cloverage'? I've tried 'lein cloverage -n "some-regex" but that does not work. it seems that cloverage will read the lein's :source-paths property no matter what options i'm passing to lein cloverage. any idea?
12:16	xcthulhu	Is there a way to insert if not exists in clojure?
12:16	xcthulhu	Erm, korma
12:18	logic_prog	for a svg group element, is it possible to (1) set it's size and (2) setup a background color? or do I have to (3) put a rectangle in the svg group element?
12:18	logic_prog	wrong channel, sorry
12:19	logic_prog	though if you're an svg expert, you're welcome to answer
12:20	munderwo	Hi all, I played around with the clojure koans a little while ago and in that the jam that ran the tests stayed running and re-ran the tests when a file changed? Is there a plugin that makes that happen?
12:24	supersym	erh...clojure 'import' doesn't error on ficticious names?
12:24	supersym	no way of telling
12:27	supersym	oh... only on ns directives it does I see
12:28	instilled	xcthulhu: you can use a raw query to achieve that.
12:28	xcthulhu	logic_prog: For a <g> in sag, you can set it's dimensions, and you can also set its scale using a transformation attribute
12:28	xcthulhu	s/sag/svg/
12:29	xcthulhu	stupid auto-correct
12:29	xcthulhu	Also its*, but that's just me being bad at grammar so I can't blame autocorrect on that one
12:30	xcthulhu	You can't set the background in a <g>; I recommend using a <rect> for that
12:30	andyf_	Bronsa: ping
12:31	Bronsa	andyf_: pong
12:31	xcthulhu	instilled: Yeah, whenever I'm using an ORM, part of me just wants to cut to the chase and use RAW SQL
12:31	andyf_	jonasen: That use of datomic looks interesting. I'll have to understand it some day, but not today :-)
12:32	xcthulhu	But then someone always complains about Little Bobby Tables...
12:33	andyf_	Bronsa: I haven't been understanding all of your (very welcome) changes to Eastwood's code for calling the analyzer, and was trying to a bit more. Do you consider 'emit-form' a phase of analysis, compilation, code generation, or something else? I know that there might not always be a clear bright line between those.
12:34	Bronsa	andyf_: basically emit-form transforms an AST back into a clojure form
12:34	Bronsa	andyf_: the problem was this: suppose you have (defmacro x [] (println "foo"))
12:34	andyf_	Bronsa: Would you expect a CinC compiler to need emit-form? Or is it intended for debugging purposes?
12:35	Bronsa	when you call (analyze '(x) (empty-env)) it gets macroexpanded and "foo" gets printed
12:35	Bronsa	then we eval that, we macroexpand it again and print "foo" twice
12:35	Bronsa	calling emit-form on the AST returns an already macroexpanded ofmr
12:36	Bronsa	andyf_: I don't use emit-form in t.a.jvm or t.e.jvm, it's there for convenience
12:36	andyf_	OK, so this is part of the changes you made where the commit comment mentioned macros with side effects.
12:36	LordVanSprang	Raynes, ping
12:37	Bronsa	andyf_: yes, the other part is, if analyze has a bug and returns a wrong AST, we're now trying to eval the form corresponding to that AST
12:37	xcthulhu	Bronsa: Looks like you want "once-only" semantics for macros:
12:37	Bronsa	this makes it crash instead of simply accepting a wrong AST
12:37	xcthulhu	http://tsdh.wordpress.com/2011/09/23/once-only-evaluation-for-clojure-macros/
12:37	Bronsa	and i can fix it.
12:37	xcthulhu	Doug Hoyt would be pleased
12:38	instilled	xcthulhu: i suggest you write it as raw sql and forget about it :)
12:38	xcthulhu	instilled: Yeah, someone's gonna complain about Little Bobby Tables probably
12:38	andyf_	Bronsa: So this way of doing it should also give more complete test coverage of tools.analyzer. That's good.
12:38	xcthulhu	But so much for ORMs
12:39	Bronsa	andyf_: yeah, the failures you're seeing on core.async have nothing to do with TANAL-30, I'm investigating now the cause
12:40	andyf_	Bronsa: I am going to try adding in some code to Eastwood to catch exceptions from emit-form, and eval, so that Eastwood's messages can give everyone (but especially us) a quick indication of where the exception is occurring.
12:41	Bronsa	yeah, that would be nice. right now most of the errors will be swallowed by a "no method in multimethod -emit-form for value null" or something like that
12:43	andyf_	Bronsa: I wasn't yet thinking of making it more refined than that, just give a likely guess as to why that exception is occurring. You are saying that sometimes that same exception is thrown for different root cause than TANAL-30 example?
12:43	Bronsa	yes
12:45	andyf_	OK, I will make sure to make any error message I make for now have weasel words like "this might be because of X, but there may be other reasons", and elaborate on those more later.
12:46	Bronsa	yeah, don't spend too much time on that.
12:47	andyf_	Most of my time on Eastwood now is spent finding new categories of crashes :-)
12:47	Bronsa	and I thank you for that :P
12:47	Raynes	LordVanSprang: Hi.
12:50	LordVanSprang	Raynes, would you know where Chousuke the Finn is at?
12:51	LordVanSprang	Also, I Worship His Shadow.
12:51	Raynes	lol
12:51	Raynes	gg
12:51	Raynes	Bronsa: How comes the Clojure in Clojuring?
12:53	Bronsa	Raynes: working mostly on the analyzer these days, will go back on the emitter once the analyzer is stable :P
12:57	bbloom	Bronsa: mmm decomplection
13:08	pcn	Raynes: Sorry to bother you, but I have a question about importing your fs module
13:08	pcn	rather requiring it
13:09	Raynes	Sure, shoot
13:09	pcn	I've got it in my project.clj: [me.raynes/fs "1.4.5"]
13:09	pcn	but when I lein repl, I keep getting this message#<FileNotFoundException java.io.FileNotFoundException: Could not locate fs__init.class or fs.clj on classpath: >
13:10	Raynes	What code are you typing?
13:10	Raynes	(require '[me.raynes.fs :as fs])
13:11	pcn	The core.clj has a (ns [...] :require [me.raynes/fs :as mrfs]
13:11	pcn	Ah me.raynes.fs not /fs
13:12	Raynes	:)
13:13	pcn	Is there a doc about what that means - the difference between lein's dependencies syntax and the require syntax?
13:13	pcn	Or as in this case how they're probably only tenuously connected?
13:14	andyf_	pcn: require uses Clojure namespaces. Leiningen uses Maven artifact/<something>
13:14	andyf_	Probably Maven <group>/<artifact>
13:14	andyf_	A single line in the project.clj file could pull in many many namespaces
13:16	pcn	I feel like little pitfalls like this will be a fact of life. I've been dodging java since it was created, so I'm not particularly good with its ecosystems
13:16	pcn	andyf_ thanks though, that does give me a point of reference.
13:27	pcn	'10
13:29	andyf_	pcn: If you want a form to be evaluated in the IRC channel, put a , first
13:31	egosum	andyf_: he was quoting it; he wanted to prevent evaluation ;)
13:31	pcn	Sorry, that was my tmux binding for commands leaking out :(
13:32	pcn	Raynes: really, java 1.6 doesn't have methods for hard links?
13:32	pcn	Wow
13:34	pcn	It doesn't look like seq can be run on a namespace to check for functions existing? I want to issue a loud "fail" if I can't get fs/link.
13:34	pcn	What can I do to check that?
13:35	bbloom	i wish my file browser could topologically sort files by the dependency tree, rather than alphabetically
13:36	bbloom	i've gotten so used to reading big clojure files in order. i dunno what to do when there are like 10 files :-P
13:36	Raynes	pcn: Check ns-publics.
13:36	pcn	(ns-publics fs) seems to fail: CompilerException java.lang.RuntimeException: Unable to resolve symbol: fs in this context [etc.]
13:36	pcn	but the namespace is otherwise valid
13:37	TEttinger	quote it?
13:37	Raynes	That isn't a namespace. That's a symbol.
13:37	Raynes	&(doc ns-publics)
13:37	lazybot	java.lang.SecurityException: You tripped the alarm! ns-publics is bad!
13:37	Raynes	ugh
13:37	pcn	l0l
13:37	TEttinger	,(doc ns-publics)
13:37	clojurebot	"([ns]); Returns a map of the public intern mappings for the namespace."
13:37	Raynes	,(doc the-ns)
13:37	clojurebot	"([x]); If passed a namespace, returns it. Else, when passed a symbol, returns the namespace named by it, throwing an exception if not found."
13:37	Raynes	(ns-publics (the-ns 'me.raynes.fs))
13:41	pcn	OK, I'll put the difference between the local binding and the ns on my list of things for deep thought. Thanks!
13:42	alew	Can I rely on the lein function eval-in-project to return the last form evaluated?
13:44	pepijndevos	probably
13:44	alew	It seems to want to return nil... and looking at the source I can't figure out why that would be
13:45	Bronsa	andyf_: mhph this is a problem ##`(~Object ~'Object)
13:45	lazybot	⇒ (java.lang.Object Object)
13:46	Bronsa	,#`(~Object ~'Object)
13:46	clojurebot	#<RuntimeException java.lang.RuntimeException: Reader tag must be a symbol>
13:46	TEttinger	,`(~Object ~'Object)
13:46	clojurebot	(java.lang.Object Object)
13:47	Bronsa	,#((juxt identity (partial mapv class)) `(~Object ~'java.lang.Object))
13:47	clojurebot	#<sandbox$eval115$fn__116 sandbox$eval115$fn__116@16e6127>
13:47	TEttinger	one # will return the anon fn
13:47	Bronsa	,((juxt identity (partial mapv class)) `(~Object ~'java.lang.Object))
13:47	clojurebot	[(java.lang.Object java.lang.Object) [java.lang.Class clojure.lang.Symbol]]
13:48	TEttinger	that's uh interesting
13:48	TEttinger	one has Object and one has java.lang.Object...
13:48	andyf_	Bronsa: Did you find an example of that in the wild?
13:48	coventry	In what context is that a problem? Isn't it what you'd expect?
13:49	Bronsa	andyf_: yeah, this is what's breaking core.async
13:50	Bronsa	because the defprotocol macro returns {:on the.protocol :on-interface the.protocol ..}
13:50	Bronsa	except one is a symbol, the other a class
13:50	coventry	Oh, I see.
13:50	Bronsa	but when we eval that, they both get evalauted as a Class
13:50	hyPiRion	Well
13:50	hyPiRion	,(binding [print-dup true] (pr-str `(~Object ~'java.lang.Object)))
13:50	clojurebot	"(#=java.lang.Object java.lang.Object)"
13:51	Bronsa	andyf_: I don't know if I can "fix" the emit-form pass to wrap symbols with a (quote the-sym), we may need to use a different fix for avoiding a doubl eevaluation
13:51	Bronsa	hyPiRion: yeah well, the problem is we need to eval the form
13:52	andyf_	"We" meaning in the context of Eastwood linting
13:52	hyPiRion	oh, hm.
13:55	Bronsa	A possible solution would be to walk the form replacing all the symbols with (list 'quote symbol), but we need to do that only outside of a (quote ..) form
13:55	Bronsa	so clojure.walk is a no-go there
13:56	coventry	riddley will avoid walking into quoted forms.
14:00	andyf_	Bronsa: Don't mean to distract you, but regarding TANAL-30, when you say that this is a Clojure bug, do you mean that you believe that correct Clojure code for calling a fn in another namespace that is type-hinted with a Java class return value, that Java class must be imported wherever that function is called?
14:01	Bronsa	no, the opposite. the tag should get qualified
14:04	andyf_	Bronsa: Qualified meaning a full Java package.classname ? But if it is not imported, in the calling namespace, how would fully qualifying it in that way help it compile?
14:05	andyf_	Pardon my ignorance, but fully qualified package.classnames can be used without importing them?
14:05	Bronsa	andyf_: it should be qualified in the def
14:06	Bronsa	e.g. you have (ns foo (:import bar.Baz)) (defn x ^Baz [])
14:06	Bronsa	andyf_: sure
14:06	Bronsa	,Collection
14:06	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: Collection in this context, compiling:(NO_SOURCE_PATH:0:0)>
14:06	Bronsa	,java.util.Collection
14:06	clojurebot	java.util.Collection
14:07	andyf_	Got it. I've got to leave now. Thanks for the info.
14:07	Bronsa	np
14:12	ksaua	say i have a function, A, which returns a lazy sequence of numbers. How do I then create another function, B, which takes this function and lazily returns latest element of function A + last element of function B?
14:13	bbloom	ksaua: did you say that right? B is going to return something from itself?
14:14	ksaua	B is another function that returns a lazy seq
14:14	ksaua	so, yes?
14:14	bbloom	can you be more concrete about what you want? ie provide an example
14:14	ksaua	sure
14:15	ksaua	I have a function, A, which returns the following lazy sequence [1 2 3 4 5 7 ...], How do I create a function B, which takes A and returns [1 3 6 10 15 22 ..]
14:16	ksaua	if A had instead returned [1 1 1 1] B(A) would return the lazy seq [1 2 3 4]
14:16	bbloom	first, vectors with square brackets are not lazy. you're looking for parens :-)
14:17	ksaua	heh, yeah, i mean parens
14:17	bbloom	so you want to basically want to sum A0+A1, A1+A2, A2+A3 ... etc yes?
14:17	ksaua	Yup
14:18	coventry	,(doc reductions)
14:18	ash__	^-- any storm users here?
14:18	clojurebot	"([f coll] [f init coll]); Returns a lazy seq of the intermediate values of the reduction (as per reduce) of coll by f, starting with init."
14:18	bbloom	,(let [a [1 2 3 4 5 7]] (map + a (cons 0 a)))
14:18	clojurebot	(1 3 5 7 9 ...)
14:19	AeroNotix	Emacs/Clojure/Flymake, what do people use?
14:19	bbloom	something like that?
14:19	bbloom	but yeah, reductions is awesome too
14:19	bbloom	oh you don't want parallel sums, you want successive sums
14:20	bbloom	yeah, use reductions
14:20	ksaua	Hm, sure, as long as that works where a is a lazy sequence, which i guess it does because map and cons is lazy?
14:20	bbloom	cons is not lazy
14:20	bbloom	,(reductions + 0 [1 2 3 4 5 7])
14:20	clojurebot	(0 1 3 6 10 ...)
14:21	bbloom	,(next (reductions + 0 [1 2 3 4 5 7]))
14:21	clojurebot	(1 3 6 10 15 ...)
14:21	bbloom	cons will preserve laziness past the non-lazy, prepended head
14:21	ksaua	okay
14:21	ksaua	I'll try reductions, seems to be what im looking for, thank you so much
15:21	logic_prog	how does parsec handle operator precedence?
15:27	pepijndevos	logic_prog #haskell?
15:28	coventry	Incidentally, what is the right channel for svg questions?
15:29	hyPiRion	the graphics format?
15:29	logic_prog	pepijndevos: good call
15:29	logic_prog	#svg
15:29	coventry	logic_prog: Thanks. hyPiRion: Yeah.
15:29	rovar	I'm trying to work through the clojure emacs to tutorial.. and it's telling me to execute tests via C-x C--
15:30	hyPiRion	coventry: Well, I'd guess if there's not a lot of activity within #svg, you could piggyback on some JS framework using svg for visualisation.
15:30	hyPiRion	their IRC channel, that is
15:30	rovar	ooh nm
15:31	noncom	,(name nil)
15:31	clojurebot	#<NullPointerException java.lang.NullPointerException>
15:31	dav	Is there a way to get lein test to print even when a test succeeds?
15:31	dav	Some verbosity level or something?
15:31	noncom	there is a problem ^ (name nil) gives up an exception. is there a way to write something like (or (name passed-name-maybe-nil) "default-name") ?
15:32	noncom	without risking an excetion
15:32	noncom	oh just realized that i can put (or) inside (name)!
15:32	noncom	nevertheless, it is weird that it gives an NPE
15:33	eric_normand	noncom: (if x (name x) "default")
15:33	coventry	,(doc fnil)
15:33	clojurebot	"([f x] [f x y] [f x y z]); Takes a function f, and returns a function that calls f, replacing a nil first argument to f with the supplied value x. Higher arity versions can replace arguments in the second and third positions (y, z). Note that the function f can take any number of arguments, not just the one(s) being nil-patched."
15:33	justin_smith	,((fnil name "nil") nil)
15:33	clojurebot	"nil"
15:33	justin_smith	,((fnil name "nil") :ok)
15:33	clojurebot	"ok"
15:34	noncom	yes, i know the (if) approach but it is not as cool as (or)!
15:34	eric_normand	noncom: fnil is good, too
15:35	noncom	hmmm (fnil).. never heard of that.. but actually i just realized i can do (name (or smth "default")).
15:35	noncom	howwever thanks for the insight on fnil
15:35	noncom	is there any library for clojure that performs intelligent seatch like one in SublimeText?
15:35	noncom	s/seatch/search
15:36	noncom	like picking strings by relevence from a pool of strings
15:39	pepijndevos	define relevance
15:40	noncom	pepinjndevos: uhm.. it is hard to explain exactly.. just if you have used SublimeText 2 text search, then you would know. in its menus, it sorts items in the menu list in the order starting from the best matches
15:41	noncom	the point is that if you enter like "pc" and you have "popcorn" and "peach cake" and "pc" and "pocket" then the order will be like "pc" "pocket" "popcorn" "peach cake"
15:42	justin_smith	sounds like levenstein difference
15:42	justin_smith	http://en.wikipedia.org/wiki/Levenshtein_distance sp. sic
15:42	justin_smith	http://clojuredocs.org/incanter/1.2.3-SNAPSHOT/incanter.stats/levenshtein-distance
15:42	justin_smith	looks like it comes with incanter?
15:43	amalloy	i doubt if it's levenshtein distance, since then "id" would sort before "pocket", which seems pretty rubbish
15:43	justin_smith	ahh
15:43	justin_smith	good point
15:43	justin_smith	I wonder how iswitchb does it
15:44	justin_smith	it reminds me of that behavior
15:44	pepijndevos	i remember fish does this too
15:44	coventry	justin_smith: I haven't looked, but my impression is that time of last visit plays a big role there.
15:45	justin_smith	coventry: fair enough, but even on a virgin checkout it does sort matches based on character subset
15:45	cYmen	How do I install cider when this marmelade thing doesn't work?
15:46	coventry	justin_smith: Is it doing some kind of fuzzy matching? I thought it was just exact substrings.
15:46	justin_smith	cYmen: wait for them to fix it, or install package from a git checkout
15:46	justin_smith	coventry: it does fuzzy matching with my config
15:46	justin_smith	though that may be because of some customization I forgot I did
15:47	noncom	hmm, people menthion Levenshtein distance here too : https://www.sublimetext.com/forum/viewtopic.php?t=5661
15:47	noncom	mabye it is some superset of it
15:47	noncom	or a subset :D
15:47	justin_smith	yeah, some parameterized generalization from it maybe
15:48	hyPiRion	I'd guess they use Damerau-Levenshtein
15:48	hyPiRion	And perhaps take into account keyboard layout
15:48	dav	Is there a way to get lein test to print even when a test succeeds?
15:49	coventry	cYmen: https://github.com/clojure-emacs/cider#manual
15:50	hyPiRion	dav: Are you interested in feedback from a test, or actually doing printing?
15:51	dav	hyPiRion: having some generic printing while tests are running
15:51	hyPiRion	ah
15:52	dav	hyPiRion: I ended up writing this macro: http://paste.debian.net/71019/
15:52	dav	hyPiRion: wondering if there's a better way.
15:53	hyPiRion	dav: huh, `lein test` would print out e.g. "lein test my-lib.test.combined" whenever running that test namespace
15:54	cYmen	coventry: My lack of prior emacs knowledge makes it hard to fill in the gaps. :)
15:54	hyPiRion	along with total tests + assertions, plus failures and errors
15:55	coventry	cYmen: Try this: mkdir -p ~/.emacs.d/vendor && cd ~/.emacs.d/vendor && git clone https://github.com/clojure-emacs/cider.git
15:55	coventry	cYmen: Then put (add-to-list 'load-path "~/emacs.d/vendor") (require 'cider) in your ~/.emacs file.
15:56	coventry	Oh, you'll have to install clojure-mode, dash.el and pkg-info the same way. What a pain.
15:56	cYmen	Oh, I can't use the ones from marmalade?
15:56	coventry	If they install, that should be fine.
15:57	cYmen	In that case I don't understand what's wrong.
15:57	cYmen	File error: Cannot open load file, cider
15:57	pinkwerks	I'm missing some basic let usage and hiccup, how do i get both :h1 & :h2 to generate with this form? I only get the :h2 back : (let [dbval 1] [:h1 dbval] [:h2 dbval])
15:58	cYmen	Oh wait, I put it in my init.el
15:59	cYmen	As expected that didn't change anything.
15:59	amalloy	pinkwerks: the forms in a 'let are evaluated for side effects, and only the last one is actually returned, so of course hiccup can't render the :h1 (which you never returned)
15:59	amalloy	instead, hiccup lets you use lists to group things: (let [dbval 1] (list [:h1 dbval] [:h2 dbval]))
16:00	coventry	cYmen: Oh, you'll probably need (add-to-list 'load-path "~/emacs.d/vendor/cider") if that's the path you put the cider repository on. Someone should PR the README to clarify.
16:00	pinkwerks	amalloy : now I understand thanks
16:01	cYmen	coventry: I tried that as well, didn't work either. d)
16:01	cYmen	:)
16:02	coventry	C-h v load-path RET. Check that it's actually getting on the load-path.
16:03	cYmen	Hm..that list is very long.
16:03	coventry	Search with C-s. :-)
16:04	xeqi	cYmen: are you using ~/emacs.d or ~/.emacs.d ?
16:05	xeqi	in the (add-to-list load-path ..)
16:05	cYmen	xeqi: That was exactly the error that I just corrected. How do you know? :)
16:05	xeqi	ran through the manual install yesterday
16:05	cYmen	haha
16:06	xeqi	something else to be PR/fixed in the cider readme
16:06	cYmen	xeqi: Other things I should know? Like why can't I just M-x cider-jack-in now? :/
16:07	cYmen	Is that some shortcut that marmalade has added on my other machines?
16:07	xeqi	I usually open a clojure file and C-c C-j
16:07	emaphis	in reference to cYmen's question, would it be unwise to install cider from Melpa?
16:08	xeqi	works for me with the clojure-mode, dash.el and pkg-info from marmalade, and cider manually downloaded off melpa
16:08	coventry	In nrepl, at least, C-c M-j just does nrepl-jack-in.
16:08	xeqi	emaphis: I'm not big on running from master (like melpa does)
16:09	cYmen	Well, according to my emacs that symbols definition is void.
16:09	xeqi	C-c M-j is what I mean
16:09	emaphis	Yes, I just leave Melpa alone. :-)
16:09	cYmen	C-c M-j in a clojure file seems to work.
16:10	cYmen	sigh
16:10	cYmen	Using tools you only understand a fraction of, so much fun.
16:10	justin_smith	and what function does that run?
16:10	justin_smith	M-x describe-key
16:11	cYmen	nrepl-jack-in
16:13	cYmen	So...what does this mean?
16:13	amalloy	justin_smith: why M-x describe-key rather than C-h k?
16:13	justin_smith	they do the same thing, no?
16:13	justin_smith	I find for learners presenting the name rather than mnemonic helps
16:13	justin_smith	just a style thing I guess
16:14	amalloy	makes sense, i suppose
16:14	coventry	cYmen: It's unclear why nrepl-jack-in failed the first time and C-c M-j worked the second, since they are apparently doing the same thing.
16:14	cYmen	The first time I tried cider-jack-in.
16:14	justin_smith	amalloy: also it will tell you the key shortcut after any m-x command, so that info is still provided
16:14	coventry	Ah, right.
16:14	Bronsa	me too.
16:15	cYmen	Which works on the machines where I installed it with marmalade.
16:15	justin_smith	sounds like version skew
16:16	cYmen	Probably. Anyway, as usual, thanks for the great support.
16:18	bbloom	,(bit-or 5) ; aw sad face
16:18	clojurebot	#<ArityException clojure.lang.ArityException: Wrong number of args (1) passed to: core/bit-or>
16:21	letstest	Hi - I am bumbling along trying to learn clojure. I am trying to use a clojure library in the repl. how would I use a particular library. The one I am trying to use is this - "https://github.com/jdhollis/forecast-clojure"
16:21	letstest	what do I have to do in the repl to have access to it?
16:23	justin_smith	letstest: I would say adding the maven coords to your project.clj :dependencies vector
16:23	justin_smith	(in a project)
16:23	letstest	oh ok. I have to add it to a project. I can't just try using it without that
16:23	justin_smith	and then setting up the credentials in your ~/.lein/profiles.clj as they show in their readme
16:23	justin_smith	well you CAN, but that is not easier
16:24	letstest	alright. I will do that
16:24	justin_smith	(there is alembic / pomegranate)
16:24	letstest	i.e put it in project.clj
16:24	letstest	thank you
16:24	justin_smith	then for the key, probably easier to go the env var way, if you know how to set a shell environment variable
16:24	justin_smith	np
16:25	letstest	going to try it now
16:30	letstest	justin_smith - i did that and got into the repl and saw it being downloaded. But, when I do (require '[forecast-clojure.core :as forecast]) - i get back nil. What does that mean?
16:31	coventry	letstest: successful import.
16:31	letstest	oh! thanks coventry but when i use it (forecast "37.8267" "-122.423")
16:32	letstest	i get this CompilerException java.lang.RuntimeException: Unable to resolve symbol: forecast in this context, compiling:(/tmp/form-init1327445774299770078.clj:1:1)
16:32	letstest	shouldnt that have worked?
16:32	coventry	letstest: The readme is wrong. Try replacing forecast with forecast/forecast (guessing.)
16:33	letstest	i get back nil if i do that
16:33	letstest	user=> (forecast/forecast "37.8267" "-122.423") nil
16:35	coventry	Probably means the api call failed somehow. https://github.com/jdhollis/forecast-clojure/blob/master/src/forecast_clojure/core.clj#L14
16:35	letstest	oh
16:35	letstest	i may have set my environment variable wrong
16:35	letstest	strange error if that is the case
16:37	noncom	why it is not that a namespace is a clojure datastructure, why is it something so different?
16:37	bbloom	noncom: a few reasons. for one thing, they are mutable
16:37	bbloom	by design
16:38	bbloom	noncom: also, they exist before clojure is fully bootstrapped, so there's that too
16:38	justin_smith	letstest: you can set env variables with (System/setenv "var" "new-value")
16:38	justin_smith	without restarting that is
16:39	noncom	hmm, i see, yes that makes..
16:39	noncom	i have to learn more about environments though
16:40	noncom	oh you were talking to a different person1
16:45	letstest_	justin_smith - do i need someting in my project.clj to do that?
16:46	justin_smith	no, that works right in the repl
16:46	justin_smith	as long as the library looks in the env for the credentials that should work
16:46	letstest_	i get "CompilerException java.lang.IllegalArgumentException: No matching method: setenv, compiling:(/tmp/form-init1327445774299770078.clj:1:1) "
16:46	justin_smith	erm...
16:47	justin_smith	I could have sworn there was a setenv
16:47	justin_smith	I was likely confused, sorry
16:47	letstest_	np
16:48	letstest_	would be useful if there was :)
16:48	justin_smith	I guess as far as the jvm is concerned mutating the env is non-portable
16:49	letstest_	oh
16:50	hyPiRion	justin_smith: yes, that's exactly the reason
16:52	letstest_	i still cant get that library to work, just gives me nil
16:53	letstest_	is there a tutorial or article that that someone can point me to show how to write a similar library? Maybe I have to write my own
16:53	justin_smith	if you do (System/getenv "FORECAST_KEY") does that show your api key?
16:53	letstest_	let me try
16:53	letstest_	oh - nope
16:53	letstest_	gives me nil
16:53	justin_smith	env FORECAST_KEY=supersecret lein repl
16:54	letstest_	ok
16:54	justin_smith	try that from the command line in the top level of your project
16:54	justin_smith	and in the repl that runs you should be able to use the API
16:55	letstest_	That worked!!
16:55	letstest_	thank you!
16:55	justin_smith	awesome
16:55	justin_smith	np
16:55	justin_smith	so you can start your process with the var explicitly that way, or put the env key in your profiles.clj (as it mentions in that project's docs)
16:56	letstest_	i actually did try profiles.clj but it didnt work. Will fool around with the environment variables. i have had similar problems before
16:57	letstest_	now that i know this works. The issue is on my end
17:26	rukor	qz: /quit
17:31	noncom	how do i stop a server in nrepl?
17:32	noncom	(stop-server) accepts some args map but not what (start-server) returns
17:32	justin_smith	(System/exit 0) ?
17:32	noncom	:)
17:32	justin_smith	or do you mean some subprocess?
17:32	noncom	yeah, in my app i start an nrepl server
17:32	justin_smith	ahh
17:33	justin_smith	does it have a .stop method by any chance?
17:33	justin_smith	there should be a thread / process like object somewhere in what it returns, I would assume
17:34	noncom	(start-server) returns something like #clojure.tools.nrepl.server.Server{:server-socket ..bunch of stufff goes here ...}
17:34	noncom	what is that?
17:34	noncom	#Server{} what datatype is this?
17:35	noncom	oh its a defrecord..
17:35	noncom	never used one
17:35	justin_smith	a record from defrecord
17:35	justin_smith	https://github.com/clojure/tools.nrepl/blob/master/src/main/clojure/clojure/tools/nrepl/server.clj#L52
17:35	justin_smith	this is the code for stop-server
17:35	justin_smith	may help
17:35	noncom	so you were completely right, it is Cloaseble
17:36	justin_smith	well my first guess was .stop
17:36	justin_smith	but yeah
17:37	justin_smith	yeah, now that I look at the definition for Server defstruct, it implements close from Closeable
17:38	noncom	and i look too and see that (stop-server) must work with it. so it is a mistake somewhere in my code
17:39	justin_smith	.close calls stop-server
18:00	danielszmulewicz	technomancy: ping
18:06	logic_prog	is there a good explaination somewhere of how clojure's ident rules work (as implemented in emacs) ?
18:12	logic_prog	is there a way I can construct a symbol/object/something-magical that clojure.edn/read-string can not construct?
18:12	logic_prog	context: I'm annotating some clojure sexps, and I need certain annotations (that include data) that can not be part of any valid clojure sexp
18:12	bbloom	logic_prog: trivially:
18:12	bbloom	,(Object.)
18:12	clojurebot	#<Object java.lang.Object@844a08>
18:13	logic_prog	thinking
18:13	bbloom	specifically, that's what the #<...> syntax is for
18:13	logic_prog	bbloom: googling for "#<...>" might be slightly troublesome
18:13	logic_prog	can you point me at readin gmaterial?
18:14	emaphis	logic_prog: the rules for indenting lisp have aways been what emacs does. :-)
18:14	logic_prog	emphais: it's like how python the interpreter is python the spec?
18:15	bbloom	logic_prog: the magic word you're looking for is "unreadable"
18:15	bbloom	logic_prog: https://github.com/clojure/clojure/blob/master/src/jvm/clojure/lang/LispReader.java#L109
18:15	emaphis	logic_prog: good analogy. ;)
18:16	hyPiRion	,#<this is not readable by the reader>
18:16	clojurebot	#<RuntimeException java.lang.RuntimeException: Unreadable form>
18:19	logic_prog	does clojure provide some type of ordered list that has an O(log n) time insert?
18:20	logic_prog	vector's insert into the middle is O(n) time afaik
18:20	logic_prog	I want an ordered list where I can say "insert this after the n-th element" and have it be O(log n) time
18:23	akhudek	logic_prog: sorted-may or sorted-set
18:24	akhudek	logic_prog: that should be lorted-map
18:24	logic_prog	you may wish to invest in a new keyboard :-)
18:24	akhudek	logic_prog: work fingers, sorted-map
18:24	logic_prog	or a spell checker
18:24	`cbp	or invest less in alchohol
18:26	bbloom	logic_prog: see also https://github.com/clojure/data.avl
18:26	logic_prog	https://github.com/clojure/data.avl <-- is this meant to be empty?
18:26	justin_smith	logic_prog: insertion in a vector is guaranteed O(<7)
18:26	justin_smith	not O(n)
18:27	logic_prog	it's not O(length of vector?) ?
18:27	justin_smith	no
18:27	logic_prog	oh, this is chunks o 32 ?
18:27	justin_smith	O(7) is the worst case
18:27	justin_smith	yeah
18:27	gozala	Bronsa: I’d like to ask a question about tools.reader
18:27	bbloom	logic_prog: heh, sorry. guess michal didn't move the code over yet: https://github.com/michalmarczyk/avl.clj
18:27	logic_prog	so it can use chunks of 32 even if I don't insert 32 elements at once?
18:27	justin_smith	wait this has nothing to do with chunking
18:27	gozala	Bronsa: where does it saves column, line info for booleans and nil ?
18:27	Bronsa	gozala: tell me
18:27	justin_smith	it is the same tree structure used to implement persistent hashmaps
18:27	Bronsa	gozala: it doesn't
18:28	Bronsa	gozala: booleans and nil cannot have metadata attached to them
18:28	akhudek	there is also https://github.com/clojure/data.priority-map
18:28	logic_prog	bbloom: interesting, I always thought people used red-back trees, not avl for persistent trees
18:28	justin_smith	logic_prog: it uses a tree, max 7 levels deep, so assoc to a random index is at worst O(7)
18:28	gozala	Bronsa: so there is no source map for those then ?
18:28	bbloom	logic_prog: if you need sorted with nth, that's what AVL is for
18:28	Bronsa	gozala: there's no way to attach such info to objects that cannot have metadata attached to them
18:28	bbloom	logic_prog: clojure does use red/black trees
18:28	logic_prog	justin_smith : sure, but how do you get that insertion is only O(7) ?
18:28	amalloy	O(7) is like...a crime against notation
18:28	justin_smith	O(<7)
18:28	logic_prog	say, I have a list of 3200 elements
18:29	justin_smith	7 is the worst case
18:29	justin_smith	because it is a tree
18:29	logic_prog	and I insert a element at index 6
18:29	amalloy	O(<7) is even worse
18:29	justin_smith	7 levels deep max
18:29	gozala	Bronsa: yeah I was hoping there was some clever hack I could not come up with :/
18:29	logic_prog	it seems like that all the remainig elemnts gets "shifted"
18:29	pcn	Is there a way to loop, and ahve the initial bindings replaced, that doesn't rely on recur being in tail position?
18:29	logic_prog	I can believe that replace an elemento f a vector is O(log_32 n)
18:29	justin_smith	amalloy: just qouting "clojure high performance programming"
18:29	Bronsa	gozala: no I'm sorry
18:29	logic_prog	but I'm not convinced that insertion is O(log_32 n)
18:29	justin_smith	logic_prog: why would assoc shift anything?
18:30	justin_smith	yo uare replacing a single index
18:30	amalloy	justin_smith: all of those directly translate to "O(1) but i don't understand big-O notation"
18:30	justin_smith	amalloy: OK
18:30	logic_prog	because I'm inserting into an array, it had 3200 elements. Now it has 3201 elements
18:30	justin_smith	logic_prog: it is not an array
18:30	logic_prog	and if I insert at index 6, it seems that indices 7 to 3200 might all get shifted
18:30	justin_smith	it is a tree
18:30	gozala	Bronsa: tnx
18:30	justin_smith	no, no shifting
18:30	logic_prog	damn it, where is the source for clojure vectors ? :-)
18:30	justin_smith	that is the point of the tree
18:30	hyPiRion	clojurebot: PersistentVector.java?
18:30	clojurebot	Cool story bro.
18:31	amalloy	logic_prog: you can't insert-and-shift into a vector cheaply, only insert-replacing
18:31	logic_prog	amalloy: so "insert-and-shift" is O(n), correct?
18:31	justin_smith	amalloy: I think he knows that, and that's why he thought insert would not be cheap
18:31	logic_prog	this is what I'm confused about
18:31	hyPiRion	logic_prog: yes
18:31	justin_smith	logic_prog: I thought you meant insert as in "put this at that index", not "shift everything else to the right"
18:31	logic_prog	okay. great. Now, back to earlier question: is there some sorted-structure, where I can say "insert after k-th" elemnet, and it takes me only O(log n), where there is n elmeents in the collection.
18:32	hyPiRion	clojurebot: PersistentVector is https://github.com/clojure/clojure/blob/master/src/jvm/clojure/lang/PersistentVector.java
18:32	clojurebot	You don't have to tell me twice.
18:32	logic_prog	justin_smith: sorry for not being clear, I meant "insert" not as in "replace"
18:32	hyPiRion	oh man
18:32	logic_prog	clojurebot has attitude
18:32	logic_prog	next thing you know, it's going to pass the turing test
18:32	andyf_	amalloy: I know what you mean, but O(7) = O(1) clearly from the definition of big-O notation.
18:32	amalloy	andyf_: yes, of course
18:32	hyPiRion	logic_prog: ordered structure or sorted?
18:33	logic_prog	hyPiRion: imagine I'm implementing a really giantass todo list
18:33	logic_prog	and I click on an item, and I say "insert todo right below this item"
18:33	amalloy	but equally it's O(1024), and introducing arbitrary integers doesn't make things any clearer
18:33	hyPiRion	logic_prog: ordered then
18:33	andyf_	By the same argument O(log_32 n) is a crime against big-O notation.
18:33	hyPiRion	logic_prog: http://infoscience.epfl.ch/record/169879/files/RMTrees.pdf
18:33	logic_prog	andyf_: how is O(log_32 n) bad? it's the same as O(log n)
18:33	hyPiRion	O(log_32 n) insert-at times
18:33	andyf_	but often constant factors are important to call out explicitly
18:33	akhudek	https://github.com/clojure/core.rrb-vector
18:34	hyPiRion	(inc akhudek)
18:34	lazybot	⇒ 1
18:34	andyf_	logic_prog: O(log_32 n) = O(log n), I know. I'm just commenting on amalloy's comment that O(7) is a crime against the notation.
18:34	logic_prog	O(<7) is weird
18:34	bbloom	logic_prog: use a sorted set and simply set the new item's key to the average of the target item & next item's keys
18:35	andyf_	Oh, and if O(7) is being used to apply to hash sets and hash maps in Clojure, they are only that if there are no hash collisions.
18:35	andyf_	When there are hash collisions, hash sets and hash maps can be O(n).
18:35	justin_smith	andyf_: if you are using numeric index, how would you collide?
18:35	justin_smith	we were talking vectors
18:35	andyf_	justin_smith: Sorry, I didn't read carefully enough which data structures the O(7) was being applied to.
18:36	logic_prog	hyPiRion, akhudek: nice, thanks, rrb vectors look like what I want
18:36	andyf_	Also anyone who wants to use the avl.clj library should do some performance testing -- last time I checked (but didn't publish results), their constant factors make them noticeably slower than other Clojure data structures I was comparing against.
18:38	andyf_	amalloy: I don't think the 7 is arbitrary. We often use instructions executed as a time measurement, but on most recent processors the number of accesses to DRAM, i.e. cache misses, is often a far better measure of observed performance. I know that doesn't alter your argument on big-O notation abuse, but 7 cache misses is a lot better than 25 cache misses in practice.
18:39	joshua___	Hmm. I'm using lighttable and running functions that take a while to finish. Lighttable seems to be quitting mid-computation. Do I have to use a different IDE or have I just done something wrong?
18:44	logic_prog	rrb-vectors are badas
18:44	logic_prog	s
18:46	andyf_	The answer is probably staring me right in the face, but I don't see it. If I clone the Github repo for contrib lib data.zip, create a simple project.clj for it, start 'lein repl', and (require '[clojure.data.zip :as z]) it gives an error. There is no such error in a different project if I make data.zip a dependency.
18:48	justin_smith	andyf_: maybe you need to set the :src-path for leiningen?
18:48	andyf_	justin_smith: I have :source-paths set to ["src/main/clojure"], which works for other Contrib libs
18:49	justin_smith	yeah, that looks right for clojure.data.zip
18:49	andyf_	There is something different about data.zip, though.
18:50	Bronsa	andyf_: I was wondering why that didn't work too
18:51	andyf_	Hmm. Could it be because there is an empty file src/test/clojure/clojure/data/zip.clj, and I also have :test-paths set to ["src/test/clojure"] ???
18:51	lazybot	andyf_: Oh, absolutely.
18:52	Bronsa	if lazybot says so.
18:52	andyf_	That empty file should probably be removed from the repo, or filled in with something useful, but it does seem odd that this happens as it is.
18:53	andyf_	Yep, removing that empty file and the require works fine.
18:54	andyf_	back later...
19:12	joshua___	Are there any good tutorials on setting up Clojure in Eclipse?
19:26	coventry	joshua___: I hear Cursive Just Works.
19:46	justin_smith	cursive is intellij, but yeah I have heard good things about it
19:47	justin_smith	it is only available as a preview beta that you have to sign up for at the moment
19:50	akhudek	I use cursive, it's very good. Don't think you need to sign up. Just follow the instructions in the getting started docs of the EAP.
19:51	joshua___	Oh no. I think I found out why my long running function wasn't returning results in lighttable. Tried the same thing in Eclipse and got: OutOfMemoryError Java heap space org.sqlite.NativeDB.column_text (NativeDB.java:-2).
19:51	akhudek	It's aimed to eventually be a paid plugin though, good to know if you were expecting something open source. Think it's worth the money though.
20:00	bitemyapp	yissss, have Halloway's attention on the Datomic documentation issues.
20:00	bitemyapp	I have a glimmer of hope, once again!
20:02	talios	is datomic's documentation as wonderful as clojures then?
20:03	bitemyapp	Datomic is really nice, but there is some implicit/semi-implicit information that needs documented.
20:25	logic_prog	why is (. js/console log (= :asdf "asdf")) false if cljs treats keywords as strings
20:26	logic_prog	[edit: in the context of cljs, not clj] ==> why is (. js/console log (= :asdf "asdf")) false if cljs treats keywords as strings
20:26	justin_smith	logic_prog: does it treat them as (name kw) or as (str kw)?
20:26	amalloy	logic_prog: "cljs treats keywords as strings" is very inaccurate
20:26	justin_smith	because if it treats them as (str kw) you want ":asdf"
20:26	logic_prog	amalloy: how are keywords stored in cljs?
20:26	logic_prog	I thought they were just js strings, but apparently not
20:27	logic_prog	cljs ==> (. js/console log (= :asdf ":asdf")) <- also returns false
20:27	amalloy	i know at one time they were implemented such that :foo was a string containing some wild unicode character followed by the characters f o o
20:27	amalloy	there was some talk about making them real objects; i don't know if that ever happened
20:28	amalloy	in any case how they're stored in the underlying representation isn't very important; what matters is that the clojure functions such as = treat them as keywords
20:28	logic_prog	https://groups.google.com/forum/#!topic/clojurescript/bSFK6CEE3PE <-- has this been integrated into mainline?
20:29	logic_prog	I have another dumbass question
20:29	logic_prog	in practice, when do "cljs treats keywords as strings" actually matter ?
20:31	amalloy	logic_prog: https://github.com/clojure/clojurescript/blob/master/src/clj/cljs/compiler.clj#L206 is how cljs emits keyword literals
20:31	Bronsa	andyf_: I just used eastwood on tools.analyzer[.jvm] and found out some misplaced docstrings :)
20:32	amalloy	new cljs.core.Keyword(...)
20:32	bbloom	logic_prog: even before keywords were reified, that wouldn't have worked
20:33	bbloom	logic_prog: previously, keywords had some marker bytes in the front of the string
20:33	logic_prog	(thinking)
20:33	logic_prog	suppose I have a = :abc
20:33	logic_prog	is there a way to define b = "some crap"
20:33	logic_prog	such that (= a b) returns true?
20:33	logic_prog	(in cljs)
20:33	bbloom	logic_prog: no. why do you want that anyway?
20:34	logic_prog	bbloom: good. I don't want that.
20:34	logic_prog	"keywords are implemented as strings" confused me
20:34	bbloom	where does it say that?
20:34	bbloom	it's outdated
20:35	logic_prog	damn it, I actually can't find a refenrece
20:35	logic_prog	I thought it was https://github.com/clojure/clojurescript/wiki/Differences-from-Clojure , but it no longer states that
20:35	logic_prog	I am happy now.
20:35	bbloom	logic_prog: https://github.com/clojure/clojurescript/wiki/Differences-from-Clojure/_compare/2b66b7399e036d0703a07dd94f07bf7489b4579f...e524b1bf81bf1f14c06689670f77585816c653e2
20:36	logic_prog	bbloom: ah, thanks :-)
20:37	bitemyapp	new hpmor.com chapters out.
20:45	andyf_	Bronsa: Yep, there are a fair number of those throughout Clojure contrib libraries, and even one in Clojure itself.
20:46	andyf_	I am (perhaps unrealistically) hoping to get Clojure core to adopt Eastwood or some variation of it for running automated checks on contrib libraries at some point.
20:47	Bronsa	yeah, I just ran ./lint.sh. Looks like all the failing libraries now are due to known bugs/limitations
20:47	bbloom	andyf_: have you submitted patches for the misplaced docstrings? :-)
20:47	andyf_	bbloom: I could, but that might lead them to believe there was no use to adopt a linter for regular automated checks :-)
20:48	bbloom	andyf_: i ran a blame & it makes me feel better about myself that rich screws up the docstring order sometimes too :-P
20:48	andyf_	bbloom: Call it passive aggressive or whatever you like, but I'd prefer if they were able to see that there are things that could bear cleaning up, and an automated process in place going forward is a good idea worth putting in place.
20:49	andyf_	My original motivation for this was not the misplaced docstrings, but the deftest's with repeated names that silently cause some unit tests never to be run.
20:50	bbloom	andyf_: have you talked to alex miller? he's probably the place to start w/ discussions about improving process
20:50	andyf_	bbloom: I agree, and he and I have a good working relationship. I don't think I'm ready to approach him on this topic just yet, until Eastwood is a bit more tested.
20:51	ddellacosta	eavesdropping on you guys...what is Eastwood?
20:51	andyf_	A lint tool for Clojure
20:51	bbloom	andyf_: always good to start conversations early. i'd tell him your goal & ask him what it would take to get you there
20:51	andyf_	https://github.com/jonase/eastwood
20:51	ddellacosta	ah, https://github.com/jonase/eastwood
20:51	ddellacosta	right, thanks andyf_
20:51	bbloom	andyf_: if you wait until you feel it's 100% done, you'll just be disappointed when you sit around waiting for them to act
20:51	andyf_	bbloom: I am used to waiting 1 year for things
20:51	bbloom	andyf_: i think the lines not dots thing applies here too :-)
20:52	andyf_	bbloom: Lines not dots thing?
20:52	bbloom	andyf_: http://www.bothsidesofthetable.com/2010/11/15/invest-in-lines-not-dots/ <- it's about investments/startups, but it's true of mental/emotional investments too :-)
20:53	andyf_	bbloom: I am mentally and emotionally prepared for Clojure core never to adopt an automated process for this, ever.
20:54	andyf_	I just hope they do.
20:54	bbloom	andyf_: so then you won't be disappointed now, just like you won't be disappointed later :-)
20:55	bbloom	andyf_: set up a cron job to run it yourself, then submit a dozen patches & label each one with "This was discovered by Eastwood. A tools.analyzer based lint tool."
20:55	andyf_	bbloom: If they don't within a year or so, I'll consider it.
20:55	bbloom	heh ok
20:57	amalloy	was eastwood always based on tools.analyzer? i thought it was around before then
20:58	bbloom	amalloy: appears not https://github.com/jonase/eastwood/commit/3789514b6729f0dd15ee01443207cfef0cbafdd6
20:58	amalloy	oh wow, that's a really recent change
20:58	andyf_	I started updating it to tools.analyzer about 2 weeks ago, and Nicola has been fixing tools.analyzer bugs like a man possessed since then.
20:58	bbloom	(inc bronsa)
20:58	lazybot	⇒ 14
21:00	andyf_	Look at the graph on this page: http://dev.clojure.org/jira/browse/TANAL
21:01	andyf_	Every time the green line goes up, that is Bronsa's work :-)
21:02	hyPiRion	And by the looks of it, every time the red line goes up, that is andyf_'s work :p
21:02	Bronsa	andyf_: looks like eastwood just found a bug in core.logic highfive
21:02	Bronsa	(inc andyf_)
21:02	lazybot	⇒ 1
21:03	joshua___	How do I check the amount of memory java has in clojure. I'd be trying to say something like long heapMaxSize = Runtime.getRuntime().maxMemory(); but can't figure out how to write the first part of that in Clojure
21:03	Bronsa	well.
21:03	Bronsa	(inc andyf)
21:03	lazybot	⇒ 1
21:03	andyf_	Yeah, I haven't been on IRC much.
21:03	andyf_	highfive Which bug?
21:04	bbloom	Bronsa: how is having all the separate components working out? i'd imagine well, but i'm wondering if there were some subtle circular references lurking in clojure in a way that is annoying
21:04	hyPiRion	,(.. Runtime getRuntime maxMemory) ; joshua___
21:04	clojurebot	#<CompilerException java.lang.SecurityException: Reference To Runtime is not allowed, compiling:(NO_SOURCE_PATH:0:0)>
21:04	hyPiRion	well, that should work in a repl
21:06	Bronsa	andyf_: I have absolutely no idea what's the cause, but it looks like some macro in core.logic is emitting a (partition some-var), and partition doesn't have a 1-arity
21:06	andyf_	Oh, yeah, I've seen that one before. It seems to be buried in a macro somewhere.
21:06	Bronsa	bbloom: it's definitely easier to develop this way as every component is a box -- not as easy to debug as I would have imagined though
21:07	joshua___	Thanks hyPirion
21:07	bbloom	Bronsa: what causes the debugging challenge?
21:07	Bronsa	bbloom: this https://github.com/clojure/tools.analyzer.jvm/blob/master/src/main/clojure/clojure/tools/analyzer/jvm.clj#L349-L355
21:08	Bronsa	bbloom: in short, there are some passes that depend on each other so multiple runs are required
21:08	Bronsa	when a bug is buried in one of those passes, it's difficult to reproduce the exact condition that caused the bug
21:08	bbloom	Bronsa: hmm, i'd imagine
21:09	bbloom	Bronsa: do you have a validation pass of some sort?
21:09	bbloom	or multiple, a la the nanopass language definitions idea?
21:10	Bronsa	bbloom: I have a validation pass but that's probably not what you're thinking
21:10	bbloom	if i'm reading this correctly, "cycling" is just a fixed point rewrite?
21:10	Bronsa	it checks for wrong arities & throws, tries to reflect methods etc
21:11	bbloom	ah ok so that's user level validation, not internal consistency checks for the analyzer
21:11	bbloom	makes sense
21:11	bbloom	Bronsa: typeos: https://github.com/clojure/tools.analyzer/blob/master/src/main/clojure/clojure/tools/analyzer/passes.clj#L67-L72
21:12	bbloom	s/Shortrand/Shorthand/g
21:12	bbloom	s/typeos/typos
21:12	Bronsa	duh. thanks
21:13	bbloom	Bronsa: i'd be interested to know if some of the "cyclic" passes would be better addressed with a dynamic reference attribute grammar
21:14	bbloom	my experiments there: https://github.com/brandonbloom/ascribe
21:14	bbloom	i didn't do a cyclic evaluator, but it's pretty straightforward
21:14	Bronsa	bbloom: I'll look into that and let you know
21:15	Bronsa	I'm off to sleep now
21:15	bbloom	Bronsa: the literature is a pretty deep rabbit hole
21:15	bbloom	"Extensible Compiler Construction" is a good entry point
21:15	Bronsa	noted
21:15	bbloom	and this is a good practical implementation: https://code.google.com/p/kiama/wiki/Attribution
21:16	bbloom	(scala)
21:16	joshua___	Has anyone else had the problem that the :jvm-opts ["-d64" "-Xmx2g"] part of there lein project file was being ignored when using Eclipse as the IDE?
21:16	bbloom	Bronsa: gnight
21:17	hyPiRion	joshua___: may be that you're using an old leiningen version. Try out :jvm-opts ^:replace ["-d64" "-Xmx2g"]
21:20	pcn	Heya, I've got a function that I want to run in a thread, and have it handle I/O. Most of the program is using core.async, and I'm wondering if I should be able to do this with thread from core.async, or if there's a better way to have something sit on a channel and perform disk I/O based on that?
21:21	hyPiRion	pcn: maybe agents? See http://clojure.org/agents
21:24	joshua___	hyPiRion: thank you for trying to help, unfortunately adding the :^replace didn't seem to do anything. Still getting the same totaltMemory
21:27	pcn	hyPiRion: Maybe? I want this to close a file if it's not written to in a very short time, so I don't think I want it to be an agent since it responds to async events as well as looping
21:28	pcn	Is there an easy way to just start a thread aside from agents?
21:30	ddellacosta	compsci question: if I have a sorting algorithm, like an insertion sort, which is considered stable, but then I go and use Clojure's immutable data structures to implement it, can it still be considered stable? Seems like the answer would be "no," but I'm not sure it's even a meaningful distinction when using immutable data structures, is it?
21:31	amalloy	ddellacosta: i can't imagine why the answer would be no
21:31	amalloy	"stable" doesn't mean something like "moves no memory around", it means that an already-sorted list, if sorted again, will not be reordered
21:33	ddellacosta	amalloy: okay, thank you. I think I'm struggling with the definition of "stability," so this is helpful.
21:34	amalloy	http://en.wikipedia.org/wiki/Sorting_algorithm#Stability
21:34	hyPiRion	joshua___: I guess it's not a problem with the jvm opts, but how the jvm tends to ignore memory bounds
21:34	ddellacosta	amalloy: yeah, I was looking at that, thanks
21:35	hyPiRion	ddellacosta: it just means that if an element a appears before another element b in the list, and they "are equal", then, a will be before b in a sorted list
21:37	ddellacosta	hyPiRion: yes, I think I was getting confused by all the examples I've been reviewing, which exclusively seem to use c/c++ pointer semantics to move things around. But after considering what you and amalloy are saying, I realize that I'm confused about the difference between where things reside in memory and the implications of the algorithm itself--it doesn't matter so much how you swap something--whether that be by generating a
21:37	ddellacosta	new immutable data structure that swaps the elements vs. swapping their pointer addresses--but where you place them relative to other elements, in terms of what the sorting algorithm dictates.
21:38	hyPiRion	ddellacosta: exactly :)
21:38	andyf_	ddellacosta: You can force any sorting algorithm to be stable by first comparing the items, and if they are equal, compare their original indices in the input list as a tie-breaker. But some sorting algorithms can be made stable without adding that extra info or doing the extra comparison.
21:38	amalloy	indeed. sorting algorithms really can't have anything to do with memory, since you can apply the same algorithm to bits of paper in the real world
21:39	ddellacosta	andyf_: gotcha...thanks.
21:39	andyf_	The Computer History Museum in San Jose has a great collection of mechanical radix sorters built by IBM in the early and mid 20th century
21:40	ddellacosta	oh, I was just reading about radix sort in the Cormen book...very cool. Would love to see that.
21:40	andyf_	You feed it a stack of punched cards, and adjust a setting to indicate which 'column' contains the digit you want to sort on, and it takes an input stack of cards and sorts them into 10 separate piles.
21:41	andyf_	Recursion on the next digit position requires manual intervention :-)
21:41	ddellacosta	oh wow, haha
21:51	pcn	Is there a way to start a polling thread instead of a reactive thread?
21:52	coventry	What is the difference between the two types?
21:53	pcn	My understanding of an async thread per an agent is that it's waiting for activity
21:54	pcn	I want a thread that will run a loop
21:54	coventry	You can use the java thread API as you can in java.
21:55	pcn	I was hoping there was something as simple as core.async/thread
21:57	hyPiRion	Well, a Thread isn't necessarily hard in Clojure
21:58	hyPiRion	(doto (Thread. #(if (wait-condition) (recur) (do-something-and-quit))) (.start))
22:00	pcn	OK, I'll broaden my horizons
22:00	bbloom	is there an easy core.async equiv for Go's Ticker? specifically with these properties: http://golang.org/src/pkg/time/tick.go?s=765:917#L1
22:04	amalloy	hyPiRion: why would you (doto (Thread. f) (.start)) rather than (future (f))? the only difference i know of is bindings conveyance
22:06	hyPiRion	amalloy: If you want to interrupt the Thread or need some other means to poke around at it?
22:07	hyPiRion	Well, I guess cancel and isCancelled would provide that too
22:22	bbloom	$mail tbaldridge I need http://golang.org/pkg/time/#Tick please :-)
22:22	lazybot	Message saved.
22:23	amalloy	bbloom: that's a channel that emits a message every X timeunits? why do you need that from tbaldridge? seems like it's easy enough to build yourself
22:24	coventry	Yeah, that go code looks pretty easy to translate.
22:24	bbloom	amalloy: it is easy enough to build yourself, however depends on a platform specific clock
22:24	bbloom	coventry: it uses the internal clock facilities to deal with period drift
22:24	bbloom	the interesting bit is the dropping to handle slow consumers
22:24	bbloom	you need to measure how much time has passed & schedule your next timeout accordingly
22:25	rovar	wouldn't ticking into a bounded channel do the same job?
22:25	bbloom	it's pretty easy to implement, but needs to use either (System/getCurrentMilliseconds) or (js/Date.)
22:25	bbloom	rovar: no, because the interval needs to be adjusted
22:25	rovar	does go's Tick really adjust its interval?
22:26	bbloom	rovar: read the comments on the NewTicker function: http://golang.org/src/pkg/time/tick.go?s=1482:1515#L40
22:26	rovar	the challenging part is actually understanding when the consumer consumes..
22:26	bbloom	http://golang.org/pkg/time/#NewTicker specifically
22:26	bbloom	that's not tricky if you have a 1 item buffer
22:27	bbloom	amalloy: also, it's much less efficient to build it in terms of timeout channels b/c you allocate a channel every tick
22:27	bbloom	amalloy: if you have a high frequency timer, that's a non-trivial savings you can have by using a non-allocating underlying timer
22:27	rovar	fair enough, so you just need to count the interval between the blocking write success
22:28	amalloy	fair enough
22:28	rovar	so you're basically getting as fast as the consumer but no faster than n
22:28	rovar	seems like a reasonable thing to have for UI's
22:28	bbloom	rovar: precisely why i want it :-)
22:31	rovar	so you'll need to be able to measure intervals of 16ms accurately
22:47	rovar	how does one get cider to connect to an existing nrepl?
22:47	rovar	I am running a webserver process which also spins up an nrepl port
22:48	rovar	but cider doesn't pick up on that and spins up its own process.
22:49	coventry	rovar: Try M-x nrepl (works in nrepl.el)
22:53	rovar	ah
22:53	rovar	instead of running cider-jack-in, I just run cider
22:54	rovar	which seems counterintuitive
22:54	coventry	Yes, the inconsistent name-change policy is frustrating.
22:59	rovar	hmm
22:59	rovar	so i'm attached to the nrepl for my web server.. but I can't access any of my symbols..
23:00	rovar	even though I've loaded the bufer with C-c C-k
23:00	rovar	not that I think I'd have to..
23:00	coventry	rovar: Have you set the namespace with something like C-c M-n in the buffer where you ran C-c C-k?
23:02	rovar	that doesn't seem to do anything..
23:03	coventry	What does ns return in the repl?
23:03	rovar	hum
23:03	rovar	the correct thing
23:03	rovar	I guess it did behave correctly
23:04	coventry	Can you access the symbols in that ns, now?
23:13	rovar	coventry, yea. it's just wierd that there is no response from the UI when one types C-c M-n
23:16	coventry	What happens if you type (in-ns 'user) at the repl?
23:18	rovar	clojuremud.core> (in-ns 'user)
23:18	rovar	#<Namespace user>
23:18	coventry	Yeah, that is weird.
23:19	rovar	it all works now.. so I'm not too concerned
23:21	v4n	Any recommendations for handling hmac-sha256 with clojure?
23:22	v4n	I saw clj-oauth, but it is an overkill for what I need.
23:54	SegFaultAX	v4n: javax.crypto has everything you need to do hmac sha256
23:54	SegFaultAX	v4n: If you can't find a self contained example already written in Clojure, try your hand at translating a Java implementation.
23:56	v4n	SegFaultAX: Thanks, just got it working with javax.crypto.