#clojure – 2012-01-06

2012-01-06

00:50	jodaro	wow
00:50	jodaro	lamina is really nice
01:42	alexbaranosky	do any of you use lazytest?
01:43	alexbaranosky	do you keep your tests in the same namespaces as your production code? I say that, because it seems like if you modify a production file, it won't run the test that goes with it, unless that test is in the same ns...
02:07	replaca	technomancy_: you there?
02:09	replaca	TimMc: looks cool!
02:09	replaca	I like the ns comment best
02:14	alexbaranosky	is there any annotation support in Clojure? I want to try using PowerMock, but I think it requires using some annotations
02:25	hiredman	alexbaranosky: yes, deftype has some kind of annotation support, not sure if anyone has used it
02:26	alexbaranosky	hiredman, thanks, I'm playing with adding support for mocking static methods, but the JAva library I was thinking of building off of requires using annotations. More research needed
05:39	true_droid	what's the most efficient way to append elements to the end of a sequence?
05:39	true_droid	Say, I have a function which takes a sequence and modifies it in some way. But the order of elements has to be preserved.
05:39	true_droid	Multiple alternatives come to mind:
05:39	true_droid	1) start with an empty vector [], conj elements into it and then return (seq my-vec)
05:39	true_droid	2) start with an empty list (), conj elements into it and then return (reverse my-list)
05:39	true_droid	3) like the previous one, but use (into () my-list) in the end
05:39	true_droid	4) start with a list (), append each consecutive element to it with (concat my-list (list element))
05:42	philandstuff	not 4), that's for sure
05:42	philandstuff	afaik each concat is linear in terms of my-list
05:42	morphling	true_droid: concat is lazy, so that is good, but do you really have to add items one by one?
05:42	morphling	philandstuff: it is?
05:42	morphling	,(doc concat)
05:43	clojurebot	"([] [x] [x y] [x y & zs]); Returns a lazy seq representing the concatenation of the elements in the supplied colls."
05:43	philandstuff	morphling: ooh ta
05:44	true_droid	hm, I haven't thought about it
05:44	true_droid	so, it depends on the use-case; whether I want the whole sequence at once or not
05:44	true_droid	in each case efficiency is defined in a different way
05:46	philandstuff	morphling: so if you build up a sequence using concat, when you call first on the resulting sequence won't that be a linear operation, because it has to go through n subsequences?
05:47	true_droid	morphling: if I'm writing a compress function which removes consecutive duplicates from a sequence, is there a way to build a new list more than one element at a time?
05:49	true_droid	as far as I get it, seq doesn't construct a new collection, it's merely an interface
05:49	true_droid	does the same go for 'reverse'? does it reuse the existing collection?
05:54	morphling	philandstuff: yes, but you don't have to traverse the entire first sequence
05:54	philandstuff	yes
05:54	morphling	philandstuff: so it's linear in the amount of concat calls, but not the length of the first sequence
05:54	philandstuff	yeah
05:54	philandstuff	in this situation, the two were equal, but it ain't necessarily so
05:55	philandstuff	so 4) is still a bad idea, but not for my original reason
05:55	morphling	yes
05:55	morphling	true_droid: you might want to use lazy-seq (or perhaps for)
05:59	true_droid	ok, thanks, I'll look into these
05:59	true_droid	*those
06:01	morphling	this is about the only case where I really miss lazy evaluation.. in haskell you'd just use reduce
08:34	AWizzArd	http://i.imgur.com/pAy4z.png
08:52	bsteuber	AWizzArd: rofl
09:04	AWizzArd	(:
09:46	mcrittenden	given these two factorial defns, why would the first one throw a stack overflow and the 2nd one works fine when (factorial 10000N) is called? https://gist.github.com/1570886
09:47	tsdh	mcrittenden: It consumes stack because it has to remember n in every recursion step.
09:48	tsdh	mcrittenden: The recur version is in fact compiled to some iterative algorithm without recursion.
09:48	rabbler	The second uses recur, which gets compiled into what is basically equivelant to a "for loop"
09:48	rabbler	Iterative is a much better response, thanks tsdh.
09:48	pandeiro	When I try to instantiate a Java class, I get a "No matching ctor found for class ...", so I am using clojure.reflect/reflect to examine the class and it seems to have an eponymous method -- that signifies a constructor in Java, right?
09:48	mcrittenden	interesting, thanks for the explanation tsdh and rabbler
09:49	tsdh	mcrittenden: Google for clojure recur, and you'll find a bunch of more elaborate explanations.
09:49	mcrittenden	tsdh yeah doing that now :)
09:57	pandeiro	Ah so Java throws the no ctor found just because the arity is off... I like clojure's error message better
10:38	AWizzArd	$seen jchoi
10:38	lazybot	I have never seen jchoi.
10:51	mcrittenden	what is a ref? http://clojure.github.com/clojure/clojure.core-api.html#clojure.core/ref is that the same thing as a managed reference? this is a concept I'm unfamiliar coming from python
10:53	TimMc	mcrittenden: http://clojure.org/refs
10:54	mcrittenden	TimMc yeah found that but it's still a little fuzzy for me. so the idea is just that you don't have to worry about different threads having a different value for it, whereas with vars you do?
11:00	mcrittenden	TimMc: never mind, after reading through that page a couple more times, I think I mostly get it
11:02	mcrittenden	this helped as well: http://en.wikipedia.org/wiki/Software_transactional_memory
11:13	pjstadig	a "managed reference" could be an atom, a var, or a ref
11:13	pjstadig	a ref is a very specific kind of "managed reference", which is a bit confusing
11:14	mcrittenden	pjstadig: yeah that tripped me up.
11:16	TimMc	mcrittenden: Once you understand 'ensure, you're probably good.
11:58	clj_newb	why is there defn- but neither def- nor defmacro- ?
12:20	TimMc	clj_newb: More need for defn-, I guess.
12:21	TimMc	You can add ^:private as needed for the others.
12:23	cgray	and it's pretty easy to write the macro for def- and defmacro- just by looking at defn-
12:30	pandeiro	how does one handle a map key with a space in it?
12:31	hiredman	,({"foo bar" 1} "foo bar")
12:31	clojurebot	1
12:32	pandeiro	,({:character count 1} ":character count")
12:32	clojurebot	#<ExecutionException java.util.concurrent.ExecutionException: java.lang.RuntimeException: Map literal must contain an even number of forms>
12:32	`fogus	,(keyword "a b")
12:32	clojurebot	:a b
12:33	hiredman	`fogus: :( don't go doing that, people might think it's a good idea
12:33	`fogus	,((keyword "a b") {(keyword "a b") :eville})
12:33	clojurebot	:eville
12:33	`fogus	It is a great idea!
12:34	hiredman	:(
12:34	`fogus	Although I prefer newlines and Klingon chars in my keys
12:34	pandeiro	yeah not my idea, you work with the libs you got...
12:38	DeusExPikachu	is there anything in enlive (or anything else) that converts a string to a url with the characters escaped?
12:39	ckirkendall	maybe: http://docs.oracle.com/javase/1.5.0/docs/api/java/net/URLEncoder.html
12:41	ckirkendall	(URLEncoder/encode url)
12:42	DeusExPikachu	ckirkendall: seems to work, thanks
12:43	ckirkendall	other than the obvious of posting to the IRC whats the best way to get the word out on a new library?
12:43	DeusExPikachu	ckirkendall: the mailing list I believe is the official place
12:43	ckirkendall	google-groups?
12:44	DeusExPikachu	ckirkendall: yes, the mailing list, which is the list on google-groups
12:45	ckirkendall	DeusExPikachu: I will put a post out there
12:46	ckirkendall	In case anyone is interested I created and enlive like dom manipulation library for clojurescript. It has all the standard transforms plus event handling and effects.
12:47	ckirkendall	Here is the demo site: http://ckirkendall.github.com/enfocus-site/
12:49	cgray	very cool
12:53	`fogus	ckirkendall: Have you looked at domina?
12:54	ckirkendall	`fogus: no
12:55	`fogus	https://github.com/levand/domina
12:55	ckirkendall	`fogus: similar concept but the semantics are bit diffrent
12:55	`fogus	On first glance your lib seems more mature
12:56	ckirkendall	`fogus: I was able to handle all of the standard enlive transformation
12:56	ckirkendall	`fogus: I then had to add all the stuff to deal with a dynamic dome
12:56	ckirkendall	dom
12:56	`fogus	it looks nice.
12:57	ckirkendall	`fogus: I am working on adding a good abstraction for extracting data from the dom
12:57	ckirkendall	`fogus: thanks
13:00	pandeiro	is there a :use-macros in clojurescript?
13:01	technomancy	replaca_: what's up?
13:02	arohner	does anyone remember seeing a new library for mongoDB? I seem to remember a new lib that claims to be better than congomongo, but I can't remember the name
13:03	ckirkendall	`fogus: bundled with something like the hiccup implementation in pinot for dom creation it makes a powerful tool for creating UI widgets.
13:04	benares_98	arohner: do you mean adia?
13:05	pandeiro	ckirkendall: have you seen hiccups?
13:05	arohner	benares_98: I don't think so. what I'm thinking of is purely a mongo library, no web stuff
13:06	ckirkendall	pandeiro: I have now nice!
13:06	jodaro	arohner: there are a couple others on github
13:06	arohner	jodaro: yes, but what are their names? or how do I find them? :-)
13:06	jodaro	monger
13:06	jodaro	karras
13:07	arohner	jodaro: monger, that's what I was thinking of! thanks
13:07	jodaro	arohner: http://bit.ly/wFeyGX
13:07	pandeiro	ckirkendall: there was a project that was sort of backbone-inspired too but it's been subsumed by something else
13:07	jodaro	i just did a search for mongo with language:clojure
13:08	arohner	jodaro: thanks. I was using google, and not being very successful
13:24	zilti	Netsplit?
13:31	solussd	why does this return a vector of two items? (re-find #"([r\-][w\-][x\-]){3}" "rwxr-xr-x")
13:32	arohner	solussd: it returns the whole match, and then the parenthesized group
13:32	solussd	ok, is there a way to say, in the regex, that I want that group 3 times without having it be a 'match group' ?
13:33	arohner	yes
13:33	arohner	(?:)
13:33	arohner	http://docs.oracle.com/javase/1.4.2/docs/api/java/util/regex/Pattern.html
13:36	mr_rm	can someone tell me what the '-' means at the front of a function name, like (defn -main ...)?
13:37	solussd	in a genclass it is a method
13:37	clj_newb	TimMc: thanks for the tip on ^:private (re: defn- vs def- defmacro-)
13:37	solussd	(the default prefix is '-', yu can change it though)
13:39	mr_rm	solussd: i saw someone use it on a generic function that was not using using genclass. they just defined a standalone function with the '-' in front of the name and i was wondering if hit had any special meaning in that context
13:39	mr_rm	https://github.com/yogthos/Noir-Eclipse-Template-Project/blob/2a91fcd8b131137e51362f6ffb3b92c4d56b349e/src/my_website/server.clj
13:41	solussd	mr_rm afaik it doesn't mean anything special, but maybe it does in the context of the noir.server library
13:42	mr_rm	solussd: ok thanks
13:45	technomancy	I love how the "not marked as dynamic" warnings don't use fully-qualified names.
13:50	yazirian	that was just irritating me too, not ten minutes ago
13:50	clj_newb	,(type identity)
13:50	clojurebot	clojure.core$identity
13:50	clj_newb	,(type identity) ; why does this not return function, and how can I check is a var is a function?
13:50	clojurebot	clojure.core$identity
13:51	clj_newb	,(meta identity)
13:51	clojurebot	nil
13:52	jodaro	clj_newb: try fn?
13:52	clj_newb	jodaro: nice; thanks
13:54	metajack	clj_newb: you might also want ifn? if you want things like :foo and {} to return true
13:55	clj_newb	i can imagine :foo is a function which extracts a label
13:55	clj_newb	but how is {} a function?
13:55	metajack	maps in clojure are functions that take keys and return values
13:56	TimMc	clj_newb: In Clojure, functions are implemented as class-per-function. identity is an instance of the identity class.
13:56	metajack	,({:foo :bar} :foo)
13:56	clojurebot	:bar
13:56	TimMc	&(class identity)
13:56	lazybot	⇒ clojure.core$identity
13:56	TimMc	&(ancestors (class identity))
13:56	lazybot	⇒ #{clojure.lang.Fn clojure.lang.IMeta java.lang.Object java.util.Comparator clojure.lang.IFn java.util.concurrent.Callable java.io.Serializable java.lang.Runnable clojure.lang.AFn clojure.lang.IObj clojure.lang.AFunction}
13:57	clj_newb	TimMc: class-per-function as in "each clojure function has a special java class created just for the function" ?
13:58	jodaro	heh
13:59	jodaro	everytime i think i've seen the radness i end up seeing more
13:59	technomancy	,(throw (RadnessOverflowException.))
13:59	clojurebot	#<CompilerException java.lang.IllegalArgumentException: Unable to resolve classname: RadnessOverflowException, compiling:(NO_SOURCE_PATH:0)>
14:00	jodaro	like a never ending horizon of radness
14:01	clj_newb	one more dumb question: is there away in clojure, given two types, to ask " can this type be automatically converted ino that type" ?
14:02	clj_newb	,(type 1) (type 1.0) (type 1919191919191919191919191919191919)
14:02	clojurebot	java.lang.Long
14:02	clj_newb	,[(type 1) (type 1.0) (type 1919191919191919191919191919191919)]
14:02	clojurebot	[java.lang.Long java.lang.Double clojure.lang.BigInt]
14:02	hiredman	depends what you mean by automatically converted
14:02	clj_newb	I need someting where (f? Long Double) (f? Long BigInt) both return true
14:03	hiredman	,(doc number?)
14:03	clojurebot	"([x]); Returns true if x is a Number"
14:03	hiredman	,(number? 1)
14:03	clojurebot	true
14:03	clj_newb	hiredman: I'm buidlging a type system on top of Clojure via macros
14:03	clj_newb	I don't want to do equality checks on types, I want to do checks of the type "A can be cast into B automatically"
14:04	hiredman	clj_newb: hardly seems like a project for a clj_newb
14:04	hiredman	but have fun
14:04	clj_newb	hiredman: what is the right questions to ask?
14:05	clj_newb	ah; I get it
14:05	clj_newb	I don't care about types
14:05	clj_newb	I care about what protocols it satisfies.
14:06	hiredman	there are a lot of questions, the first is "do I really know enough to implement a type system if I say things like 'automatically converted'"
14:07	clj_newb	hiredman: probably not
14:07	hiredman	so maybe some reading is in order
14:07	clj_newb	hiredman: what should I read?
14:08	hiredman	dunno, something about type systems, or dig into this "automatic" conversion and see what is really going on
14:10	clj_newb	hiredman: seeing how clojure does this "autoamtic" conversion is interesting; how do I grep through the source code for something ill-defined like this?
14:10	clj_newb	furthermore, does this "automatic" conversion ahppen for anything besides numbers?
14:18	TimMc	clj_newb: Correct. Each function, namespace, deftype, defrecord, proxy... each gets a class.
14:20	TimMc	clj_newb: You're probably building a precondition system, not a type system.
14:22	hiredman	clj_newb: my main point is it's not automatic, what makes you thing it is?
14:22	technomancy	is he talking about boxing?
14:23	hiredman	no
14:23	TimMc	I think he's talking about the reader.
14:24	TimMc	$findfn Long Double BigInt true
14:24	lazybot	java.lang.RuntimeException: Unable to resolve symbol: BigInt in this context, compiling:(NO_SOURCE_PATH:0)
14:24	TimMc	$findfn Long Double clojure.lang.BigInt true ; there you go!
14:24	lazybot	[clojure.core/not= clojure.core/distinct?]
14:36	cgray	is there a way to close all open files? i made a mistake and i don't want to have to reboot clojure
14:37	amalloy	(System/exit 1), cgray
14:38	amalloy	(this kills the jvm)
14:49	zilti	Is there a library to make a clojure web app multi-lingual or would I have to implement such a thing myself?
14:51	TimMc	zilti: You mean a localization thingy?
14:51	zilti	TimMc: Yes
14:58	mcrittenden	anyone have any tips for learning to write more idiomatic clojure? I feel like I'm getting a decent grip on the language and I've worked my way through koans and half of 4clojure but e.g. I never would have thought to write flatten like this: https://github.com/clojure/clojure/blob/master/src/clj/clojure/core.clj#L6272
14:58	mcrittenden	is it just experience?
15:01	technomancy	mcrittenden: you pretty much have to read lots of code
15:03	cemerick	mcrittenden: I wouldn't beat yourself up after N months with the lanugage because you wouldn't consider an impl that the creator of the language wrote. :-)
15:03	TimMc	Argh, clojure/core.clj links are like rickrolling for me.
15:03	cemerick	TimMc: Noted.
15:03	TimMc	Firefox 3.6 goes gray for like half a minute. >_<
15:04	cemerick	3.6?
15:04	mcrittenden	cemerick: oh I'm not, I feel like I'm making good progress, I'm just wondering where to go after doing koans and 4clojure to continue to progress as quickly as possible
15:04	cemerick	All enterprisey over there,huh?
15:04	TimMc	cemerick: Linux Mint. :-(
15:04	AeroNotix	is there not a native clojure file IO library?
15:04	cemerick	only about 28 of 'em.
15:04	technomancy	ff is one of two things I still install manually on debian =\
15:04	cemerick	mcrittenden: Build a real app, then build 10 more.
15:04	technomancy	can't handle JITless 3.6
15:05	TimMc	mcrittenden: clojure/core.clj is also full of nasty hacks because of bootstrapping. Watch out in the upper reaches.
15:05	mcrittenden	cemerick: haha, I hear you, I'm just a bit worried that I'll continue building stuff in my non-idiomatic way
15:05	technomancy	mcrittenden: I recommend browsing http://clojuresphere.herokuapp.com
15:05	cemerick	mcrittenden: Man, that's just life. :-)
15:06	mcrittenden	technomancy: nice, bookmarked, thanks!
15:07	TimMc	mcrittenden: flatten isn't totally idiomatic either -- I'd have gone with remove instead of filter and complement.
15:07	zilti	Why remove?
15:07	technomancy	so... what would you do if you had a full graph of all clojure projects anyway?
15:08	zilti	Ah, I was looking for that clojuresphere link yesterday but didn't remember its name, thanks!
15:08	TimMc	Because it's the same thing, only shorter and easier to read.
15:08	cemerick	technomancy: you don't have to be so coy ;-)
15:08	TimMc	technomancy: I don't see lein-jit in there! o\__/o
15:09	technomancy	cemerick: I'm just getting started!
15:09	technomancy	cemerick: my first idea is a "If I change my API in such and such a way, how will this affect the downstream consumers" plugin.
15:09	technomancy	but
15:10	technomancy	certain kinds of refactorings can be automated
15:10	technomancy	and if they can be automated within your project, why not extend that downstream?
15:10	technomancy	since you can open pull requests through the github API
15:11	technomancy	(This is actually what Steve Yegge works on with the internal Google codebase apparently)
15:11	TimMc	Won't somebody please answer this page? http://clojuresphere.herokuapp.com/ring
15:11	TimMc	It keeps saying "ring/ring, ring/ring"...
15:11	technomancy	BANANAPHONE
15:13	jowag	Hi, I have my state in an atom, and my function which updates this state also performs some side effects (io). How should I correctly update my state? (swap! state update-fn) can call update-fn more than once, so it is not a good solution...
15:13	pandeiro	zilti: you asked about localization... i'm implementing it in the app i'm working on... IMO not something you need a lib for, really. Just store it all in a strings.clj and create a fn that takes a key and a lang (or reads an atom somewhere)
15:13	zilti	pandeiro: Yes, might be the best solution. Thanks!
15:14	TimMc	pandeiro: Isn't it hard to read?
15:15	mcrittenden	how can (fn [x] x) be rewritten in anon func shorthand? #(%) doesn't work. or, in other words, how can I make (partition-by (fn [x] x) x) cleaner (as a solution to http://www.4clojure.com/problem/31)
15:15	TimMc	mcrittenden: identity :-/
15:15	cgray	,(#(identity %) 1)
15:16	clojurebot	1
15:16	TimMc	&(identity 1)
15:16	lazybot	⇒ 1
15:16	mcrittenden	thanks.
15:16	TimMc	jowag: If you use a ref, you can send the io to an agent from inside the dosync.
15:16	zilti	I just offended the whole ##javascript channel :)
15:17	pandeiro	TimMc: isn't what hard to read, the other languages? :)
15:17	zilti	"Even the shittiest scripting languages can do http" Me: "like JS?"
15:19	TimMc	pandeiro: $(:blah-key) instead of "Blah blah blah:
15:21	pandeiro	TimMc: you mean, in the application code? I'm just following the pattern that Android apps use, of separating out strings into a separate file... then when I need a string I do (loc :signup-welcome-message) or something
15:22	jowag	TimMc: thanks, nice solution. So I have to switch to refs...
15:29	TimMc	pandeiro: I don't know, it can get weird when you have marked-up text. I've seen some l10n libs use format strings, actually.
15:37	jowag	TimMc: I'm afraid agents won't work in my case. The new value of state depends on the result of the io operations. So I have to know the result of the io operation before updating the state
15:39	jsabeaudry	What is the threading model for a noir web server? One thread / request?
15:39	jsabeaudry	(using noir web server loosely here, i mean for the noir web stack)
16:14	Somelauw	,(String/format "%f" 5.4)
16:14	jcromartie	jsabeaudry: yes,
16:14	clojurebot	#<ClassCastException java.lang.ClassCastException: java.lang.Double cannot be cast to [Ljava.lang.Object;>
16:14	jcromartie	,(format "%f" 5.4)
16:14	clojurebot	"5.400000"
16:14	jcromartie	String/format expects an array of arguments
16:14	jsabeaudry	jcromartie: Great, thanks!
16:14	adiabatic	in https://gist.github.com/1572428 I'm using (seq coll) as (= () coll), but I get a ClassCastException (can't cast PersistentList$EmptyList to IFn). How should I test for empty listness if destructuring assignment isn't an option?
16:14	jcromartie	objects, to be specific
16:15	jcromartie	,(source format)
16:15	clojurebot	Source not found
16:15	Somelauw	jcromartie: ah, okay, I though String/format was variable
16:15	jcromartie	oh, well, anyway the source of "format" will shed more light on that
16:15	jcromartie	it is
16:15	jcromartie	but vararg Java methods don't work like that in Clojure
16:15	jcromartie	they require an array
16:16	Somelauw	So clojure doesn't support javastyle varargs
16:16	TimMc	Somelauw: Type... is just Java syntax for Type[]
16:16	jcromartie	here's your exact situation :) http://groups.google.com/group/clojure/browse_thread/thread/64b20acf76e2b687
16:16	jcromartie	Somelauw: Clojure itself does
16:16	kumarshantanu	Hi, is (require '[clojure.string :as str]) supposed to work in ClojureScript REPL in same way it works in the Clojure REPL?
16:16	jcromartie	Somelauw: (defn [arg1 arg2 & arg3-n) …)
16:16	TimMc	Somelauw: When Type... is compiled to bytecode, it looks exactly like Type[].
16:16	jcromartie	er, that was awful sorry
16:17	TimMc	I guess you could argue for Clojure being able to 'apply on those.
16:17	jcromartie	(defn some-vararg-fn [arg1 arg2 & more] … more is a seq here)
16:17	Somelauw	okay, thanks
16:17	jcromartie	TimMc: that would be really nice
16:19	jcromartie	TimMc: although that would definitely require reflection
16:21	TimMc	jcromartie: Not if it were explicit.
16:22	amalloy	adiabatic: you don't want the parens around accumulator
16:22	jcromartie	TimMc: at that point, though, it would be getting as verbose as any other approach
16:22	amalloy	gist is helpfully rendering it in bold-red to tell you you're calling it as a function
16:24	devinus	is there a binding to the last result in a swank REPL?
16:24	jcromartie	TimMc: although it would work if the semantics were a bit different; it would only be sort-of like Clojure's "apply"
16:24	jcromartie	devinus: *1
16:24	devinus	thanks
16:24	adiabatic	amalloy: why do I get that exception being thrown for that screwup, though?
16:24	TimMc	devinus: 1 2 3 e (exception)
16:24	amalloy	&(1)
16:24	lazybot	java.lang.ClassCastException: java.lang.Long cannot be cast to clojure.lang.IFn
16:24	devinus	thanks, i knew the book mentioend it somewhere
16:25	devinus	,*1
16:25	clojurebot	#<Unbound Unbound: #'clojure.core/*1>
16:25	TimMc	jcromartie: I guess it's really like the opposite of apply.
16:25	jcromartie	yeah :)
16:27	adiabatic	amalloy: and thanks a bunch for the help over the past few days
16:28	jcromartie	TimMc: I see a rather messy reflection-laden macro as the only solution… so I'll advocate for into-array
16:28	jcromartie	but it will continue to be a stumbling block for people trying to do interop
16:31	devinus	despite the obvious security implications, is there a way to eval a string in clojure?
16:31	TimMc	devinus: (eval (read-string ...)))
16:32	TimMc	devinus: and look up read-eval refore you use read or read-string
16:32	devinus	TimMc: hrm…okay, another question. is there a way to get the tokens clojure parses from a string?
16:32	jcromartie	devinus: the thing to remember is that Clojure (and other Lisps) evaluate data, not strings of code
16:33	jcromartie	devinus: so reading is the step that turns strings into data
16:33	jcromartie	R E P L
16:33	jcromartie	Read -> Eval -> Print loop
16:33	devinus	jcromartie: right right, i get that
16:33	TimMc	I N C E P T I O N
16:33	jcromartie	,(read-string "[1 2 {:x 3}]")
16:33	clojurebot	[1 2 {:x 3}]
16:33	devinus	i'm just trying ot get a deeper understanding of how clojure represents reader macros
16:33	TimMc	It's data all the way down.
16:33	clojurebot	Cool story bro.
16:33	devinus	e.g.
16:33	devinus	does "; foo" === "(comment " foo") ?
16:34	TimMc	nope
16:34	jcromartie	you can find out :)
16:34	jcromartie	,(read-string "; comments?")
16:34	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading>
16:34	jcromartie	,(read-string "[1 2 ; comments?\n 3]")
16:34	clojurebot	[1 2 3]
16:35	devinus	that's odd
16:35	TimMc	&[1 2 (comment 3)]
16:35	lazybot	⇒ [1 2 nil]
16:35	devinus	hrm
16:36	devinus	okay, so definitely not the same
16:36	TimMc	&[1 2 #_ 3 4]
16:36	lazybot	⇒ [1 2 4]
16:36	devinus	so how is ; a reader macro
16:36	TimMc	devinus: It isn't.
16:36	jcromartie	well the reader isn't that open
16:36	devinus	TimMc: what's happening there?
16:36	jcromartie	as far as users are concerned there aren't reader macros (as that would imply you could define them)
16:37	TimMc	devinus: When the reader sees #_ it ignores the next form.
16:37	devinus	oh interesting
16:37	cgray	jcromartie: there was a package recently announced on the list that implements reader macros
16:37	devinus	wonder whne that's useful
16:37	TimMc	#_ (comment ...) is a safe wa to comment out multiple forms without leaving a nil behind
16:37	TimMc	It's a good combo.
16:37	devinus	interesting
16:37	jcromartie	cgray: a package or a patch?
16:37	cgray	jcromartie: a package
16:38	devinus	must be why str also ignores nil
16:38	jcromartie	cgray: interesting
16:38	cgray	jcromartie: https://github.com/klutometis/reader-macros/blob/master/src/reader_macros/core.clj
16:38	TimMc	devinus: I doubt that's related.
16:38	devinus	well
16:38	devinus	relaated in that
16:38	devinus	clojure does a pretty good job of keeping brittle code from being a problem
16:39	devinus	although sometimes it's inconsistent it feels like
16:39	TimMc	devinus: ##(let [x 4 (comment y 5)] x) <-- oops
16:39	lazybot	java.lang.IllegalArgumentException: let requires an even number of forms in binding vector
16:39	devinus	offtopic, but what's the diff between clojurebot and lazybot?
16:40	TimMc	Philosophical differences, feature sets, maintainers...
16:40	TimMc	security :-P
16:40	amalloy	they also have different names
16:40	devinus	haha
16:40	TimMc	trigger characters, thank goodness
16:40	devinus	i wonder what philosophical differences
16:41	jcromartie	when I am in other programming channels, I miss having a bot that evaluates code
16:41	devinus	holy crap github just updated their interface!
16:41	amalloy	again?
16:42	jcromartie	devinus: is it Friday again?
16:42	devinus	:P
16:44	devinus	does anybody know what the status is on having a blessed standalone clj ?
16:45	technomancy	thank goodness; the grey backgrounds in the readme were way too low-contrast
16:45	technomancy	devinus: there's an open ticket for it which seems to have had no progress for many months
16:46	devinus	i'd really like to see somebody address it
16:46	devinus	i was able to traverse the waters
16:46	devinus	but i see it as a huge barrier to entry for noobs
16:50	technomancy	I'd encourage you to offer to help out, but I'm too cynical to think it would work.
16:51	devinus	technomancy: why don't you think it would work?
16:51	wei_	how do you test whether an item is an atom (in the scheme sense), e.g. not a list-like thing?
16:51	humblebot	lein repl actually worked pretty well for me, especially with rlwrap installed.
16:52	technomancy	devinus: in my experience, most patches get ignored.
16:52	TimMc	wei_: you can ask if it is a` coll?
16:52	wei_	nevermind, I found it-- coll? is the inverse
16:53	wei_	TimMc: thanks, just found that too
16:53	devinus	technomancy: that's…disconcerting
16:54	llasram	technomancy: Then who writes code that actually get included...?
16:54	devinus	technomancy: i was under the impression clojure as a language was more open than e.g. ruby, with it being on github. it seemed to me to be a much more living, moving project
16:55	technomancy	ruby is on github
16:55	devinus	didn't know that
16:55	technomancy	apparently they actually get to use pull requests: https://github.com/ruby/ruby/pulls
16:58	devinus	technomancy: clojure.core doesn't accept pull requests?
16:59	technomancy	maybe someone who's less negative could talk about it.
16:59	zilti	Could it be that swank has a problem with leiningen projects including java sources?
17:00	simonadameit	devinus: according to http://clojure.org/contributing you have to download and sign a copyright asignment agreement and send it via real mail
17:00	devinus	technomancy: -.-
17:00	zilti	simonadameit: That's almost paranoid
17:01	amalloy	i bet seancorfield could find something nice to say about the clojure.core attitude to accepting patches
17:01	technomancy	positive thinking: the great thing about Clojure is how much you can get done without making changes to clojure itself
17:02	llasram	zilti: It's not unheard of. The FSF does basically the same thing. Not doing it means that Linux is stuck with it's modified GPLv2 for all time
17:02	llasram	s,it's,its,
17:02	technomancy	llasram: the FSF allows patches under a certain size though.
17:02	technomancy	plus they're a much more high-profile target for legal action
17:02	llasram	Ah, right, I'd forgotten that
17:03	duck1123	Ok, I can't seem to find this. What do I need to do to get around a function being private? I have a need for ring.middleware.params/parse-params
17:03	devinus	i'm not a lawyer, but wouldn't a CA mean Rich could one day change the license to e.g. GPLv3?
17:03	llasram	And true. But once Clojure is the most popular language in the known galaxy... :-)
17:03	jowag	this reminds me a discussion between technomancy and lau jensen a year ago :)
17:03	technomancy	jowag: that's why I'm trying to keep my mouth shut
17:03	jowag	I know :)
17:04	simonadameit	devinus: yes… although someone else could continue clojure under the existing licence, if that were to happen
17:05	simonadameit	devinus: altleast so I think :)
17:05	devinus	that's probably not a bad idea then
17:05	devinus	well, not the GPLv3, but being able to change the license :P
17:06	duck1123	it's already happened in the early days. The CA reduces headache if changing the liscense ever becomes a good idea
17:06	jkkramer	duck1123: (def parse-params #'ring.middleware.params/parse-params) is one way (caveat coder)
17:07	duck1123	jkkramer: could I just reference the var in the fn position? trying
17:07	hiredman	technomancy: the lein script on the 1.x branch seems to be broken, missing an exec, and the exit code is always 1 on non-windows machines
17:07	jkkramer	duck1123: yes, that too
17:07	hiredman	it looks like the exec was removed around 12/30
17:08	technomancy	hiredman: the exec had to be removed to support trampolining around plugins
17:08	hiredman	well, the exit value is incorrect now
17:08	technomancy	yeah, I broke the CI because it depends on getting the uberjar from github downloads, and github only had 1.6.3
17:08	hiredman	it is now the result of the test call at the bottom
17:11	technomancy	ok, lemme fix the exit code
17:11	hiredman	I have a fix
17:11	hiredman	I could just push it?
17:11	technomancy	sure
17:12	technomancy	but src/leiningen/test.clj is compiling for you?
17:15	hiredman	technomancy: I believe so, I am using my lein check out for running tests
17:15	pjstadig	contributor agreements are used by corporate controlled open source projects to consolidate copyright and squash competition
17:15	hiredman	technomancy: on 1.x, haven't checked master
17:15	pjstadig	also this http://www.oscon.com/oscon2011/public/schedule/detail/19242
17:17	pjstadig	source for my competition squashing statement: http://www.infoq.com/articles/ieee-controlling-and-steering-open-source-projects
17:18	pjstadig	also there's nothing in the clojure CA that prevents using pull requests, which (IMO) are a far superior way of accepting and reviewing changes
17:20	pjstadig	but i guess technomancy said he wanted someone less negative :)
17:21	replaca	technomancy: slamhound is crashing nastily when I try to run it on autodoc: https://gist.github.com/1572651
17:22	replaca	technomancy: this isn't really blocking me though, since I can construct the ns to pprint by hand (or just by cutting and pasting)
17:22	technomancy	replaca: whoa; wild.
17:22	hiredman	or just read the ns form from the beginning of a file?
17:23	technomancy	if it's not blocking can you open an issue?
17:23	cemerick	Is it CA pain Fridays? :-P
17:24	pjstadig	cemerick: hehe
17:24	TimMc	cemerick: I kind of get the CA. The patches instead of pull requests thing.... that boggles me.
17:24	technomancy	cemerick: no, CA complaining is every other Tuesday; Fridays is ignored patches day.
17:24	replaca	technomancy: yup, will do
17:24	cemerick	technomancy: darn, I need to write this down!
17:25	technomancy	http://wondermark.com/506/
17:26	djh__	naive question, when the Raspberry Pi comes out - will it be able to run Clojure/a JavaVM? It's an ARM based mini computer
17:27	devinus	TimMc: i don't even remember submitting patches
17:27	pjstadig	djh__: i suppose one could compile openjdk for it
17:27	devinus	pull requests are just so damn awesome
17:27	technomancy	hiredman: are you looking at the namespaces thing?
17:27	technomancy	http://travis-ci.org/technomancy/leiningen/builds/487755
17:27	technomancy	if you're busy I can field it
17:28	hiredman	oh
17:28	djh__	pjstadig - thanks, I suppose it's just going to be a case of "wait and see"
17:28	hiredman	no, I know what I did wrong
17:28	technomancy	hiredman: if you hop in #leiningen you can get yelled at by the travis-ci bot with me =)
17:28	devinus	technomancy: no rush, but when do you think 1.4.0 is gonna make an appearance?
17:28	technomancy	devinus: of swank?
17:29	devinus	technomancy: yeah, sorry of swank
17:29	zilti	Could it be that swank has a problem with leiningen projects including java sources?
17:29	zilti	Oh sorry, didn't want to post that line it was my fault about 10 mins ago -.-
17:29	technomancy	devinus: it depends on the underlying cdt library. right now it's using a snapshot and its maintainer has been MIA
17:29	devinus	technomancy: that's unfortunate, that's the reason i wanted to see it
17:30	zilti	MIA?
17:30	technomancy	missing in action
17:30	technomancy	devinus: the snapshot seems to be working ok
17:31	hiredman	technomancy: "growled at"
17:31	devinus	technomancy: ugh, no offence i'm just trying to cut down on the unstable stuff i use so i think ill wait
17:31	zilti	What I btw really miss is an "Emacs plugin" that makes Emacs understand clojure. :)
17:31	devinus	offense*
17:31	solussd	what is the best way to test if something is a list or vector?
17:31	devinus	offence* lol
17:32	devinus	had it right the first time
17:32	solussd	sequential?
17:32	cgray	is there a good tutorial on extend-type et al?
17:32	zilti	solussd: There are functions for exactly that purpose
17:32	TimMc	devinus: Depends which side of the Atlantic you are on.
17:32	solussd	,(map sequential? [] '() {})
17:32	clojurebot	()
17:32	TimMc	solussd: list? is slightly brokenish.
17:32	solussd	,(map sequential? [[] '() {}])
17:32	clojurebot	(true true false)
17:32	TimMc	depending on how you view lists vs. seqs
17:33	zilti	,(vector? [])
17:33	clojurebot	true
17:33	solussd	looks like I want sequential?
17:33	zilti	,(vector? '())
17:33	clojurebot	false
17:33	TimMc	solussd: Check out the Venn diagram: http://www.brainonfire.net/files/seqs-and-colls/main.html
17:33	devinus	TimMc: reminds me of when i spelled behavior as behaviour for like 8 months because of erlang
17:33	solussd	thanks!
17:33	technomancy	nothing wrong with behaviour
17:34	zilti	behaviour is british, behavior is american english
17:43	solussd	why doesn't defn work with both a doctoring and pre/post conditions? if I remove the doctoring, the pre/post are respected, otherwise they're ignored.
17:43	hiredman	doctoring?
17:43	solussd	hiredman: osx lion autocorrect
17:43	solussd	*docstring
17:43	amalloy	&(doc defn)
17:43	lazybot	⇒ "Macro ([name doc-string? attr-map? [params] body] [name doc-string? attr-map? ([params] body) + attr-map?]); Same as (def name (fn [params* ] exprs)) or (def name (fn ([params ] exprs*)+)) with any doc-string or attrs added to the var metadata"
17:44	amalloy	probably you have them in the wrong order
17:44	solussd	am alloy, I'm assuming pre/post go in attr-map- but how can I refer to params before I define them?
17:44	solussd	*amalloy^
17:45	TimMc	amalloy: They go before the body, I think.
17:45	TimMc	ugh
17:45	TimMc	solussd: ^
17:45	solussd	but that doesn't work, it ignores them if there is a docstring
17:46	solussd	using 1.3, fyi
17:46	TimMc	WORKSFORME (defn foo "hi" [] {:post [false]} 6)
17:47	TimMc	solussd: Put the doc string before the args.
17:51	solussd	ok. that works, but I swear that's what I was doing…. I'll assume the repl is deterministic and chalk it up to an error on my part. ;)
17:52	amalloy	hah. i wish more people would do that
18:22	zilti	Is this my fault or a bug? "Exception in thread \"main\" java.lang.RuntimeException: Unable to resolve symbol: pst-elem-str in this context, compiling:(swank/core.clj:128)"
18:22	technomancy	zilti: you need a newer clj-stacktrace; see the swank readme's "troubleshooting" section
18:23	zilti	Ok
18:24	zilti	Do I have to set a certain namespace for the .lein/init.clj?
18:25	technomancy	no, that typically gets loaded in user
18:27	zilti	Is there something else I have to do besides installing the clj-stacktrace and pasting the text into init.clj? It didn't change the stacktrace
18:29	technomancy	could be an older version embedded in some other plugin, maybe lein-difftest
18:30	zilti	My installed plugins are clj-stacktrace-0.2.4.jar lein-clojurescript-1.0.1-SNAPSHOT.jar lein-javac-1.2.1-SNAPSHOT.jar lein-noir-1.2.1.jar lein-ring-0.5.3.jar swank-clojure-1.3.4.jar
18:31	zilti	I guess I don't need lein-javac since it's inside lein too
18:39	zilti	Hmm it still doesn't work
18:56	adiabatic	,(keep-indexed println ["spam" "eggs" "sausage" "bacon"])
18:56	clojurebot	(0 spam
18:56	clojurebot	1 eggs
18:56	clojurebot	2 sausage
18:56	clojurebot	3 bacon
18:56	clojurebot	)
19:41	srid	any heroku people here?
19:41	pdk	(* 60 .75)
19:41	pdk	,(* 60 .75)
19:41	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: .75 in this context, compiling:(NO_SOURCE_PATH:0)>
19:41	pdk	,(* 60 0.75)
19:41	clojurebot	45.0
19:47	pdk	,(* 50 0.75)
19:47	clojurebot	37.5
20:00	zmaril	Next week I am teaching clojure to a bunch of high school kids. Would it be kosher if I brought them on here and introduced them to #clojure?
20:01	zmaril	Not like one by one or anything
20:01	etosch	cool!
20:01	zmaril	But point out some of the people here, clojurebot, how to ask good questions, etc. etc.
20:08	wingie	is scala used by more people than clojure?
21:24	clj_newb	is there something like doc, but shows the :pre and :post conditions?
21:24	clj_newb	I'm basically hijacking them for type checking purposes, and I want them to show up when I retrieve the doc of a function
21:29	clj_newb	,(type (type 2))
21:30	clojurebot	java.lang.Class
21:30	clj_newb	,(type (type (fn [])))
21:30	clojurebot	java.lang.Class
21:30	clj_newb	is (type (type x)) <--- always Class ?
21:31	AWizzArd	clj_newb: no
21:31	AWizzArd	,(type (type nil))
21:31	clojurebot	nil
21:31	clj_newb	interesting
21:32	clj_newb	,(type (type ()))
21:32	clojurebot	java.lang.Class
21:32	clj_newb	,(type (type #false))
21:32	clojurebot	#<ExecutionException java.util.concurrent.ExecutionException: java.lang.RuntimeException: java.lang.ClassNotFoundException: false>
21:32	clj_newb	,(type (type f))
21:32	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: f in this context, compiling:(NO_SOURCE_PATH:0)>
21:32	clj_newb	AWizzArd: this is insightful; thanks for the counter example
21:33	chipdude	,(#Object)
21:33	clojurebot	#<ExecutionException java.util.concurrent.ExecutionException: java.lang.RuntimeException: java.lang.ClassNotFoundException: Object>
21:33	chipdude	,(#java.lang.Object)
21:33	clojurebot	#<ExecutionException java.util.concurrent.ExecutionException: java.lang.RuntimeException: Unreadable constructor form starting with "#java.lang.Object)">
21:33	chipdude	OK, never mind
21:34	clj_newb	this is somewhat off topic: anyone else feel like a genius whenever they get a defmacro to work?
21:37	AWizzArd	clj_newb: I don’t think that there is a built-in way to show the :pre or :post conditions.
21:37	TimMc	clj_newb: I usually don't feel like a genius when I finally get a piece of code to work; instead, it is more like I finally emerged victorious from a protracted fight.
21:38	amalloy	&#java.lang.Object[] ;; chipdude
21:38	lazybot	⇒ #<Object java.lang.Object@1e0a141>
21:38	AWizzArd	But one thing you could do is to define a macro over defn which preserves them, and adds them to the doc string.
21:39	AWizzArd	Such a macro could even save the full code of your function and make it accessible.
21:39	TimMc	$google serializable-fn
21:39	lazybot	[technomancy/serializable-fn - GitHub] https://github.com/technomancy/serializable-fn
21:39	TimMc	AWizzArd, clj_newb ^
21:40	AWizzArd	I did that around 2005 or 2006 in CL already.
21:42	clj_newb	AWizzArd , TimMc : interesting ;thanks
21:45	clj_newb	as I build macros around defn
21:45	clj_newb	I feeel like I"mrewriting the laws of physics
21:45	TimMc	Hey, wasn't someone looking for a type checking function the other day? 'cast appears to be the thing.
21:46	clj_newb	that was me I believe
21:46	clj_newb	,(doc cast)
21:46	clojurebot	"([c x]); Throws a ClassCastException if x is not a c, else returns x."
21:47	clj_newb	,[ (cast (type 1.0) (type 1)), (cast (type 19191919191919) (type 1))]
21:47	clojurebot	#<ClassCastException java.lang.ClassCastException>
21:48	clj_newb	,[ (cast (type 1.0) 1), (cast (type 19191919191919) 1)]
21:48	clojurebot	#<ClassCastException java.lang.ClassCastException>
21:49	TimMc	That's not a helpful message....
21:50	TimMc	clj_newb: 1 is a Long, 1.0 is a Double. You can't cast between those, although you can coerce.
21:52	clj_newb	,(doc coerce)
21:52	clojurebot	Gabh mo leithscéal?
21:55	arohner	has anyone had success with a midje (provided) in another thread?
22:02	alexbaranosky	arohner, what's the question you have?
22:03	alexbaranosky	I might be able to help you out
22:06	arohner	alexbaranosky: I'm having trouble using a (provided) against code that's called in a future
22:06	alexbaranosky	can I see a gist of your code?
22:07	arohner	i.e. (defn foo [] (future (bar))) (fact "test foo" (foo) => truthy (provided (bar) => truthy)
22:08	arohner	yeah, real gist in a second
22:09	alexbaranosky	thanks, it might need some real thought
22:09	Magnars	Given a symbol :myfn - any way of calling myfn as defined in the current namespace?
22:11	arohner	Magnars: yes, look at resolve and apply
22:11	Magnars	arohner: excellent, resolve was what I was looking for - thanks!
22:11	arohner	alexbaranosky: nvm, my simple test case works just fine. I must be doing something wrong in the real version
22:12	alexbaranosky	cool, may I ask what you're working on - is it on GitHub?
22:12	arohner	no, private project
22:12	arohner	circleci.com
22:14	arohner	oh, my future was racing. after derefing the future so it blocks, I get the expected result.
22:15	alexbaranosky	you're working on circlci.com ? neat
22:15	alexbaranosky	do you use Midje much? I love to hear feedback both good and bad
22:16	arohner	yeah, I'm one of the founders. I'm pretty happy with midje. The docs quantity and quality are good, but the organization is a little hard to navigate
22:17	arohner	and sometimes invalid syntax in the macros sometimes causes infinite hangs
22:18	alexbaranosky	arohner, I've donea LOT of work this past month working on validations of the macros, so you get error messages instead of mysterious failures
22:18	alexbaranosky	which macros in particular? I did a lot on the background and against-background
22:18	arohner	great! I'm still on 1.2.0
22:18	arohner	that's probably it. I'll investigate more the next time it happens
22:20	alexbaranosky	I've also a dded doc strings to the public api macros, so at least siome level of documentation should be available at your fingertips
22:21	alexbaranosky	arohner, I also definately consider issues people care about more when choosing what to work on, so feel free to make yourself heard if you care about some feature
22:22	arohner	alexbaranosky: great, thanks
22:25	TimMc	[Announcer voice] "Alex Baranosky: His future... was racing"
22:29	alexbaranosky	what's up TimMc
22:29	TimMc	goin' to bed
22:29	TimMc	I used up all my Clojure yesterday.
22:30	alexbaranosky	it happens :\
22:30	TimMc	alexbaranosky: lein-jit, check it out. It beat me up, but I finally won.
22:31	alexbaranosky	will do!
22:33	jodaro	ran out of parentheses?
22:44	clj_newb	here's some more: (repeat "()")
22:55	amalloy	&(nth (iterate list ()) 50) ;; gotta keep em balanced
22:55	lazybot	⇒ ((((((((((((((((((((((((((((((((((((((((((((((((((()))))))))))))))))))))))))))))))))))))))))))))))))))
23:05	pdk	,(* 40 0.75)
23:05	clojurebot	30.0
23:06	jodaro	i get mine imported from antarctica
23:06	jodaro	made by penguins
23:10	pdk	,(* 56.78 0.75)
23:10	clojurebot	42.585
23:12	pdk	,(+ 35.81 7.50)
23:12	clojurebot	43.31
23:13	jodaro	pdk: calculating tips for the week?
23:18	humblebot	,(+ 1 2 3 4 5 6 7 8 9 10)
23:18	clojurebot	55
23:18	humblebot	Cool!
23:18	humblebot	Yes, I'm new.
23:21	TimMc	technomancy: Those are bananas, you've been coding with bananas.
23:23	technomancy	as long as paredit supports 'em; I don't want to know