#clojure – 2012-02-01

2012-02-01

00:53	aphyr	Out of curiosity, how expensive is deref in clojure?
00:53	aphyr	Safe to call, say, 250K/sec?
00:54	G0SUB	aphyr, vars are getting deref-ed all the time.
00:54	G0SUB	aphyr, in 1.2 all vars are dynamic, for example. so I guess it should be pretty fast.
00:55	ibdknox	it depends entirely on what you're derefing
00:56	aphyr	ibdknox: (ref (NonBlockingHashMap.)) in this case.
00:57	aphyr	I've been using it to allow an aleph server to change its underlying configuration after being started
00:57	aphyr	But now I'm wondering if I should build some kind of reload functionality instead
00:57	ibdknox	,(time (loop [i 0] (when (< i 250000) @x (recur (inc i)))))
00:57	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: x in this context, compiling:(NO_SOURCE_PATH:0)>
00:57	ibdknox	,(let [x (atom 1)] (time (loop [i 0] (when (< i 250000) @x (recur (inc i))))))
00:57	clojurebot	"Elapsed time: 75.945 msecs"
00:57	ibdknox	,(let [x (ref 1)] (time (loop [i 0] (when (< i 250000) @x (recur (inc i))))))
00:57	clojurebot	"Elapsed time: 100.592 msecs"
00:58	ibdknox	it appears that will not be an issue
00:58	ibdknox	:)
00:58	G0SUB	ibdknox, :-)
00:58	aphyr	Haha, apparently not. :)
00:59	aphyr	,(time (loop [i 0] (when (< i 250000) (recur (inc i)))))
00:59	clojurebot	"Elapsed time: 21.745 msecs"
00:59	aphyr	,(time (loop [i 0] (when (< i 250000) (recur (inc i)))))
00:59	clojurebot	"Elapsed time: 20.966 msecs"
00:59	aphyr	So ~80ms for the var deref
01:00	aphyr	out of a 1-second timeslice, 8%... hmm. Might be worth investigating actually.
02:33	pyr	hi
02:33	G0SUB	pyr
02:34	pyr	does read-string "intern" strings on the jvm, thus making use of permgen space
02:34	G0SUB	pyr, literal strings are interned.
02:35	pyr	as well as keywords
02:35	pyr	i have a permanent process that reads of a queue
02:36	pyr	and does read-string on the input
02:36	pyr	i see constant permgen space growth
02:36	pyr	which i don't understand
02:42	G0SUB	pyr, -XX:MaxPermSize=128m -XX:PermSize=128m might be the only option.
02:43	aphyr	Wait, so any string created with read-string is on permgen?
02:43	raek	keywords are always interned (by Clojure), but strings are not always
02:43	G0SUB	pyr, apparently interned strings are GCs as expected - http://stackoverflow.com/questions/1091045/is-it-good-practice-to-use-java-lang-string-intern/2012661#2012661
02:44	raek	string literals in function bodies tend to be identical
02:45	raek	anyway, the Clojure reader does not call .intern on the strings, IIRC
02:45	raek	,(identical? (read-string "\"foo\"") (read-string "\"foo\""))
02:45	clojurebot	false
02:46	raek	,(identical? (name (read-string "foo")) (name (read-string "foo")))
02:46	clojurebot	true
02:47	raek	the names of keywords and symbols are, though
02:47	aphyr	,(.get (System/getenv) "PWD")
02:47	clojurebot	#<AccessControlException java.security.AccessControlException: access denied (java.lang.RuntimePermission getenv.*)>
02:47	aphyr	ha
02:48	aphyr	I actually could use some sandbox code right now... good to know
02:48	pyr	raek: yup, but i clearly don't have enough keyword read in
02:48	pyr	raek: to justify the growth i'm seeing
02:58	Jachy	Is there a way I can do (def (symbol ...) val) outside a macro?
03:15	raek	Jachy: not with 'def', no.
03:16	raek	there is intern though
03:18	Jachy	raek: That looks useful, thanks.
04:04	clj_newb	is it possible to ahve two separate instances of clojure share the same jvm?
04:04	clj_newb	for example, I have a simle digital led clock writen in clojure -- I think ti's a bit overkill to have it have its own jvm instance
04:05	simonj	Hi all. Confused as to the non-laziness of the returned Seq from this function. https://gist.github.com/1716056
04:22	pyr	alright, so given a huge list of strings containing pr-str'd maps
04:22	pyr	if i do: (let [m (doall (map read-string huge-list)] (Thread/sleep 10000) (println "saw: " (count m)))
04:23	pyr	i see a permgen increase which doesn't get freed up
04:23	pyr	using CMSClassUnloadingEnabled and UseConcMarkSweepGC
04:23	pyr	doesn't change a thing
05:33	yawNO	i often see in clojure libs (defn ^
05:33	yawNO	what is that?
05:33	yawNO	*def ^
05:35	ivan	yawNO: are you asking about metadata?
05:35	yawNO	i dont know asd
05:35	yawNO	i've been clojuring for like
05:35	yawNO	3days?
05:35	yawNO	so im really kinda noob right now :P
05:36	ivan	^{:a 1} (fn) attaches {:a 1} as metadata to (fn)
05:36	ivan	see also with-meta and meta
05:36	yawNO	okay got it
05:36	yawNO	thx :D
05:37	yawNO	yeah i know with-meta and meta :D
05:37	Martijn2	I just installed lein and made anew project based on clojure 1.2.0 and clojure-contrib 1.2.0 When I do (require 'clojure.contrib.str-utils) I get this error:
05:37	Martijn2	java.lang.NoClassDefFoundError: clojure/lang/RT (NO_SOURCE_FILE:0)
05:37	Martijn2	what is going on?
05:39	Martijn2	sorry, problem solved
06:40	cemerick	totally OT, but: does anyone else find it totally bizarre that the 13" Macbook Pro has a lower screen resolution than the 13" Macbook Air?
06:42	ordnungswidrig	cemerick: yes, me. now as I know the fact.
06:46	Borkdude	I installed rlwrap on my mac. how is "lein repl" supposed to use it for completion?
06:48	lucian	Borkdude: rlwrap lein repl
06:48	lucian	it literally wraps your commands
06:48	Borkdude	lucian: how does it do autocompletion then?
06:48	jondot	my first hit at useful clojure code - a ring middleware: https://github.com/jondot/ring-ping/blob/master/src/ring/middleware/ping.clj ==> anyone care to take a look and point some aweful newbie pitfalls to me?
06:48	lucian	Borkdude: oh, completion? sorry
06:48	lucian	Borkdude: for that you'd need some machinery in lein i think
06:48	cemerick	Borkdude: I can't see how rlwrap would help with completion.
06:49	lucian	cemerick: it can, actually. there was a small hack i saw for the regular clj
06:49	cemerick	command history and editing, yes.
06:49	lucian	cemerick: rlwrap can search a file of completions when you press tab
06:49	Borkdude	cemerick: command history also worked without rlwrap on my mac
06:49	lucian	Borkdude: you could generate such a file with (find-doc) or something
06:49	cemerick	lucian: oh; that's not really completion tho. :-)
06:50	Borkdude	not very intelligent completion anyway ;)
06:50	lucian	https://github.com/technomancy/leiningen/pull/381
06:50	lucian	it's terrible, really
06:50	lucian	don't bother
06:50	cemerick	Borkdude: lein will be getting some baked-in completion shortly.
06:51	Borkdude	I have some students who are trying out clojure, they used a console for it, so I thought it could be handy for them
06:52	cemerick	Borkdude: this is likely to be the new frontend for lein's repl: https://github.com/trptcolin/reply/
06:56	lucian	cemerick: that reply thing is awesome
06:56	lucian	it has precisely the features i want, and nothing else
06:57	Borkdude_	cemerick: totally cool, autocompletion works
06:58	cemerick	lucian: you want more, you just don't know it yet ;-)
06:58	lucian	cemerick: heh
07:06	cemerick	G0SUB: you have a MBA, right?
07:18	G0SUB	cemerick, lol!
07:18	G0SUB	cemerick, not at all. I have a BS in CS, that's all.
07:18	cemerick	Macbook Air :-P
07:18	G0SUB	cemerick, haha
07:18	G0SUB	cemerick, yeah, 11" MBA :-)
07:19	G0SUB	cemerick, the same as cgrand
07:19	cemerick	G0SUB: I take it the SSD makes up for anything the CPU is lacking, then?
07:19	Fossi	lol
07:19	Fossi	best ever
07:19	Fossi	you should put that on your business card XD
07:20	G0SUB	Fossi, ;-)
07:20	G0SUB	cemerick, I agree. and the CPU isn't that bad either.
07:31	G0SUB	cemerick, cgrand, ninjudd & I have the same MBA.
08:01	shales	Hi, does anyone know what version of mongodb 4clojure requires?
08:06	romain_p	Hi everyone, what is the best way of turning {:a #{:foo :bar}, :b #{:baz}} into [[:a :foo] [:a :bar] [:b :baz]] ?
08:07	lucian	maybe something like (map vec your-hash)
08:08	romain_p	,(map vec {:a #{:foo :bar}, :b #{:baz}}
08:08	clojurebot	#<ExecutionException java.util.concurrent.ExecutionException: java.lang.RuntimeException: EOF while reading>
08:08	romain_p	)
08:08	romain_p	,(map vec {:a #{:foo :bar}, :b #{:baz}})
08:08	clojurebot	([:a #{:foo :bar}] [:b #{:baz}])
08:08	romain_p	hmmm no
08:09	lucian	close, just vec again on the set
08:13	lucian	,(map (fn [item] [(first item) (vec (second item))]) {:a #{:foo :bar}, :b #{:baz}})
08:13	clojurebot	([:a [:foo :bar]] [:b [:baz]])
08:14	lucian	nvm, i must've misread
08:23	romain_p	lucian: thanks!
08:24	romain_p	oops no
08:24	lucian	romain_p: it's not what you asked
08:24	shales	,(mapcat (fn [[k v]] (map vector (repeat k) v)) {:a #{:foo :bar}, :b #{:baz}})
08:24	clojurebot	([:a :foo] [:a :bar] [:b :baz])
08:24	shales	that work?
08:24	romain_p	shales: yup that does it, cheers
08:25	babilen	How can I influence the sort order of records? I essentially want them sorted by field1 first, then field2, … What would be a good approach?
08:32	llasram	babilen: Have the records implement Comparable?
08:32	babilen	llasram: Not yet - I figured that something like this would be the best approach, but wanted to ask first.
08:35	llasram	Ok. I'm pretty sure that's the best/only way to do it
08:36	babilen	llasram: Can you, by chance, provide pointers to documentation on how to achieve this (easily)?
08:40	llasram	babilen: Just the normal way you implement interfaces for defrecords/types. Some general examples at: http://clojuredocs.org/clojure_core/clojure.core/defrecord
08:40	babilen	I am not sure how to achieve this, but figure that implementing a comparator (for e.g. sorted-set-by) is another option. (which is as far as my knowledge is concerned easier)
08:42	llasram	babilen: Here's a specific simple example: https://refheap.com/paste/527
08:43	llasram	You can also just pass a comparator (just a function returning {-1,0,1} for any argument pair) whenever you need to sort
08:43	babilen	llasram: Thanks -- Is it important that I implement in a way that allows comparison between different types or is that checked earlier?
08:44	llasram	Normal rules apply: only if you care about inter-type sorting.
08:44	babilen	llasram: I don't (at least not right now)
08:46	llasram	Ah, and the `sort' default behavior just throws an exception anyway with different types intermixed. You'll definitely need to pass in a comparator if you ever do want anything sane to happen in those cases :-)
08:50	raek	babilen: one way is to implement Comparable, and one way is to implement Comparator. one thing that's convenient is that functions of two arguments implement Comparator
08:50	babilen	llasram: Ok, that makes sense and is good news. Thanks for your kind and great help. Have a nice day!
08:52	raek	,(sort #(> (.length %1) (.length %2)) ["a" "aaa" "aa"])
08:52	clojurebot	("aaa" "aa" "a")
08:52	babilen	raek: Ok, great. Well -- I have collections of records and want them sorted by field1, field2 and don't really care about additional fields. (still need to be part of the comparison as sorted-set-by would, for example, remove all elements that differ only in additional fields)
08:53	raek	babilen: you can also use sort-by. it accepts a function that gives another value which is used for te comparisons
08:54	raek	,(sort-by (juxt length last) [[1 2 3] [1 2] [0 0 10]])
08:54	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: length in this context, compiling:(NO_SOURCE_PATH:0)>
08:54	raek	,(sort-by (juxt count last) [[1 2 3] [1 2] [0 0 10]])
08:54	clojurebot	([1 2] [1 2 3] [0 0 10])
08:54	raek	vectors and sequences are compared element wise
08:55	babilen	yeah -- I will try to implement a compare-by-field([:field1 :field2]) → comparator -- that will take additional (i.e. other not listed fields) into account, but sorts by field1 first, then field2, then the rest in no specific order. (alphabetically maybe)
08:55	raek	you can use (juxt :field1 :field2) as the key-fn
08:56	babilen	raek: Indeed - I am just not sure how to deal with the other fields that might be present in the record (yet).
08:56	raek	the ones with the same :field1 and :field2 value will be sorted next to each other in some order
09:00	babilen	raek: Shouldn't be hard though (use (keys rec) to get keys, remove given ones, ...) -- Thanks for your comments as well.
09:05	Kototama	hi, is there a way in SLIME to have slime-repl-previous-matching-input behavior more like the one from term-send-reverse-search-history (like C-r in the console) ?
09:24	noidi	is it not possible to implement two protocols (defined in different namespaces) with the same method name?
09:26	noidi	I get "Duplicate method name&signature" when I try to implement foo/Foo with foo/get-xyzzy, and bar/Bar with bar/get-xyzzy in the same reified protocol implementation
09:26	noidi	luckily I'm just playing around with this, so it's not a real problem that I'm facing
09:27	noidi	this kind of makes namespaces useless when using protocols
09:29	gfredericks	noidi: I don't know the reasoning behind it, but I think each method that you implement gets added as an actual java method on the type, without the namespace, so I'm not sure how that could be resolved
09:31	noidi	yeah, some sort of a name mangling scheme would be needed
09:32	gfredericks	which would be gross for anybody who intended to actually use the methods
09:33	noidi	well, now you need to do the name mangling manually to avoid this problem
09:34	gfredericks	true; I am not equipped to argue about the design choices.
09:34	noidi	or to avoid causing problems for the people who have to implement your protocol, possibly along with other protocols also out of their control
09:34	gfredericks	but hode up
09:34	gfredericks	the exact same problem exists with java interfaces doesn't it?
09:35	noidi	probably. I'm not that familiar with Java.
09:35	gfredericks	yeah, now that I think about it I expect this is a very general problem
09:35	cemerick	noidi: you can implement two protocols with the same signature, etc. without a problem unless you're doing so inline
09:36	cemerick	use extend-type, extend-protocol, or extend to provide protocol impls.
09:36	gfredericks	cemerick: how does it map to method names?
09:36	noidi	cemerick, thanks, I was hoping that it could be possible via extending!
09:36	noidi	I'll give that a go
09:37	cemerick	gfredericks: extend* doesn't map to method names.
09:37	cemerick	That's why it works. :-)
09:37	gfredericks	Indeed!
09:51	noidi	cemerick, brilliant, that works!
09:51	cemerick	:-)
09:52	cemerick	noidi: inline implementations are really only needed for maximum perf and Java interop.
09:55	noidi	I hope that the times I'll have to implement two Java interfaces with colliding method names will be few and far between
10:08	noidi	now if only there was a way to specify contracts directly on the protocol instead of the contract block of each method implementation...
10:09	noidi	it seems that trammel doesn't do that (yet)
10:19	cmajor7	is there a "mental rule" on where to use map/reduce/filter vs. list comprehensions?
10:20	gtrak	less/clearer code wins?
10:21	raek	cmajor7: whatever shows the intent of the code the best... :-)
10:23	cmajor7	gtrak, raek: but from a "problem solution" side. besides constantly mentally substituting both approaches ( map/reduce/filter & list compr ), is there certain indicators?
10:24	cmajor7	e.g. list comprehensions would probably make more sense when iterating over multiple seqs where each element in one seq needs to visit each element in the other…
10:24	TimMc	cmajor7: Sure. If you want to walk through a collection one at a time and use the values to hammer on some other value, 'reduce is your friend.
10:25	TimMc	especially if you are trying to maintain some invariant on that value
10:25	gtrak	reduce is aggregation
10:25	TimMc	reduce is folding
10:25	TimMc	You're folding values in, one at a time.
10:26	noidi	my own mental rule is that when I use map with a lambda, it probably reads better as a list comprehension
10:26	TimMc	list comprehensions are a Swiss Army knife
10:26	TimMc	gtrak: Challenge: Implement 'reduce using 'for.
10:27	gtrak	hmm :-)
10:27	TimMc	My gut says you can't.
10:27	gtrak	i can find a way
10:29	TimMc	cmajor7: Given a collection, 'map gives you 1-for-1 collection answer, 'filter gives you a subset, and 'reduce gives you a single value for the whole thing.
10:30	TimMc	cmajor7: So first, ask yourself which of those results is what you want!
10:31	cmajor7	TimMc: thank you. interesting.. I do understand map vs reduce vs filter. I am on list comprehensions vs map/filter/reduce… is there a difference in performace? e.g. reduce only walks once over all the seqs given and grows the accumulator, where if multiple seqs are given to "for" e.g. for [s1 (range 1 10) s2 (range 1 10)], it will walk seq2 completely for each element in seq1…
10:31	noidi	with my rule: (map #(* 2 %) (filter #(> % 5) (range 10))) --> (for [x (rang 10) :when (> x 5)] (* 2 x))
10:32	babilen	noidi++
10:32	TimMc	cmajor7: I can't imagine the performance would be different enough to care about.
10:34	cmajor7	TimMc: { btw, I also find that in several cases reduce gives you a subset => similar to a filter. the true difference between "reduce" and "filter" in my understanding, is that "reduce" would have an accumulator, which allows a _new_ seq, rather than just a subset of the existing seq that "filter" does }
10:34	TimMc	Yes, you can certainly implement filter and reverse and so forth using reduce.
10:34	TimMc	and map, for that matter
10:35	TimMc	&(reduce #(conj %1 (* 3 %2)) [] (range 10))
10:35	lazybot	⇒ [0 3 6 9 12 15 18 21 24 27]
10:36	TimMc	&(reduce #(cons %2 %1) () (range 10)) ; reverse
10:36	lazybot	⇒ (9 8 7 6 5 4 3 2 1 0)
10:38	TimMc	gtrak: I think 'for can produce a collection with at minimum the number of elements that :when and :while let through.
10:39	TimMc	Oh, and it always produces a collection, so you can't do it without at least some post-processing.
10:39	gtrak	I think there's no reason for not being able to reduce with a for, but i can't make my code work at the moment, I'm rusty :-), my basic idea is for x in the range of the length, swap an accumulator atom
10:39	TimMc	Ugh, that's terrible!
10:39	gtrak	reduce isn't lazy either
10:40	TimMc	Yeah, that's the kicker, I think.
10:41	cmajor7	seems that 'list comprehensions in fact is somewhat close to a noidi's idea of "map + filter" application to seq(s). :while is an interesting one.. would 'list compr actually stop a seq walk on the first "while false"?
10:41	TimMc	&(for [a [(atom 0)] x (range 6)] (swap! a (partial + x))) ;; reductions
10:41	lazybot	⇒ (0 1 3 6 10 15)
10:43	TimMc	cmajor7: :while will stop the current iteration only, and only at that level.
10:45	shales	does anyone know what version of mongodb 4clojure requires?
10:45	cmajor7	&(dorun (for [col "ABCD" :when (not= col \B) row (range 1 4) :while (< row 3)] (println (str col row))))
10:45	lazybot	⇒ A1 A2 C1 C2 D1 D2 nil
10:45	TimMc	&(for [l0 '[a b c], l1 '[1 2 3] :while (< l1 3), l2 '[d e f]] (str l0 l1 l2))
10:45	lazybot	⇒ ("a1d" "a1e" "a1f" "a2d" "a2e" "a2f" "b1d" "b1e" "b1f" "b2d" "b2e" "b2f" "c1d" "c1e" "c1f" "c2d" "c2e" "c2f")
10:46	cmajor7	TimMc: so the iteration actually stopped when a row became 3?
10:46	TimMc	cmajor7: Correct.
10:47	cmajor7	cool. so it is quite "controllable".. nice
10:47	TimMc	and :let makes it even better
10:49	noidi	just think of `for` as a fancy `map` :)
10:50	cmajor7	I still feel I would need to right many more maps/reduces/filters & listcomps to get the true feeling on when the one is more applicable.. but appreciate all the thoughts.. very cool.
10:51	cmajor7	noidi: 'map can't really iterate over multiple collection matching each element of one collection to all elements of another ( unless there is an internal map/reduce ). while 'listcomp can and does that. or am I missing something?
10:51	cmajor7	*over multiple collections
10:52	noidi	it can't. you'll need something like (map (fn [x] (map f x)) xs)
10:52	TimMc	cmajor7: It can, the result is just a collection of collections.
10:52	gtrak	you can do it with map, but it'd be really awkward?
10:52	TimMc	mapcat takes care of that.
10:53	gfredericks	you could do X with just a bunch of lambdas also
10:53	TimMc	cmajor7: 'for is great for unrolling nested collections, by the way.
10:53	cmajor7	doesn't mapcat just flatten the result of mapping?
10:53	TimMc	Yeah, but it does the mapping too.
10:54	cmajor7	but not on nested collections..
10:54	cmajor7	e.g how would you do this
10:54	cmajor7	&(dorun (for [col "ABCD" :when (not= col \B) row (range 1 4) :while (< row 3)] (println (str col row))))
10:54	lazybot	⇒ A1 A2 C1 C2 D1 D2 nil
10:54	cmajor7	with a single map/mapcat?
10:54	TimMc	without the :when and :while, of course
10:56	TimMc	&(mapcat (fn [c] (map (fn [r] (str c r)) (range 1 3))) "ABC")
10:56	lazybot	⇒ ("A1" "A2" "B1" "B2" "C1" "C2")
10:56	cmajor7	right => 2 maps
10:56	TimMc	sure
10:56	TimMc	which is equivalent to a 2-level 'for
10:57	cmajor7	yep.. so another mental rule would be.. "think about 2> maps? try 'it' with for"
10:57	cmajor7	(thinking out loud)
10:57	TimMc	yeah, cartesian joins
10:58	cmajor7	is there an appealing case to use 'for vs 'map on a single seq?
10:59	cmajor7	( I meant 'for vs. 'map/'filter/'reduce )
10:59	gfredericks	cmajor7: I like map with named functions and for with inline functions
10:59	TimMc	Sure, when the lambda is of moderate complexity and depends on a bunch of local s
10:59	cmajor7	besides the laziness of the result of course
10:59	TimMc	cmajor7: 'for is lazy
11:01	cmajor7	TimMc: "when the lambda is of moderate complexity and depends on a bunch of local s" => this would be strictly a readability advantage, right? [not saying it is not enough of an advantage though]
11:12	TimMc	cmajor7: A lamba of moderate to high complexity should generally be extracted as a separate named function, but if you'd have to pass it a crapload of locals, it might be better to keep it inline in a 'for.
11:13	cmajor7	TimMc: yep, makes sense. thank you.
11:13	gfredericks	(> (count locals) crapload)
13:04	muhoo	these instructions assume i have a pom.xml file. i don't. this is lein, i have a project.clj and it looks like the dependencies are there instead. http://devcenter.heroku.com/articles/local-maven-dependencies
13:05	muhoo	how woudl i translate those instructions from maven into lein?
13:05	technomancy	muhoo: I recommend using this instead: https://github.com/technomancy/s3-wagon-private
13:05	technomancy	should see about getting that devcenter article to mention it
13:06	TimMc	technomancy: But otherwise, you would just add a file: repo to your project.clj, right?
13:06	muhoo	technomancy: very cool, thanks!
13:08	technomancy	TimMc: yeah, but ... binaries in git; yuck.
13:08	muhoo	i don't mind having it on s3. and yes, binaries in git makes my skin crawl
13:09	muhoo	in fact, i don't even need credentials, i expect i could do this over http too
13:09	muhoo	this stuff isn't private or confidential, it's just not in anyone's maven repo
13:09	technomancy	oh yeah, in that case you can use http
13:18	gtrak	ha, rich hickey calls { a curly in his vid, I'm vindicated
13:31	maio	which version of Clojure is prefered for newbies?
13:32	sritchie	do you guys any recommendations on how to check equality of two regexes?
13:32	sritchie	,(= #"string" #"string")
13:32	clojurebot	false
13:32	sritchie	I guess this works:
13:32	sritchie	,(= (.pattern #"string") (.pattern #"string"))
13:32	clojurebot	true
13:32	technomancy	sritchie: yeah, that kills me
13:32	gtrak	maio: check out https://github.com/arthuredelstein/clooj
13:34	sritchie	technomancy: I wonder why implementation isn't value-based
13:34	gtrak	i don't use it, i recommend it for people to play around with? remind me of drscheme
13:35	gtrak	except, now that I try it, it doesn't work at all :-)
13:35	cemerick	maio: just grab leiningen, and you can get started in the REPL in a snap
13:36	cemerick	alternatively, there are plugins for all the major Java IDEs and emacs
13:36	faust45	what is the best way to dispatch method for empty list and not empty list?
13:36	cemerick	maio: http://dev.clojure.org/display/doc/Clojure+Tools
13:37	faust45	so i have two cases for empty list return '() and for not empty return lazy-seq
13:37	faust45	but i wish to avoid (if code
13:37	Raynes	gtrak: I mean, clooj would be a good way to get started if it even supported syntax highlighting.
13:37	gtrak	Raynes: yea, I thought it was further along than it is
13:38	Raynes	There are Clojure plugins for generally every popular editor/IDE and it is almost certain that any given person coming to Clojure is already familiar with one of them. I just don't know where clooj fits in.
13:38	maio	<- Vim guy :) I'm asking because I every now and then I end with "Exception in thread "main" java.lang.RuntimeException: java.lang.NoSuchMethodError: clojure.lang.KeywordLookupSite" errors
13:38	Raynes	Not to dismiss the fellow's work. It is quite admirable.
13:39	Raynes	maio: I use Vim too (these days, anyways). :>
13:39	Raynes	It is an excellent environment for Clojure.
13:40	raek	maio: try creating a new temp project, change the clojure version to "1.2.1", run lein deps, delete the temp project
13:41	technomancy	you're pulling in a broken plugin that declares its own version of Clojure
13:43	maio	yes. (this time) It started when I installed nailgun plugin
13:43	rlb	faust45: multiple function bodies, perhaps? (defn foo ([] 42) ([&x] 13))
13:44	maio	is there something I can do about it?
13:44	faust45	rlb: (defn foo []) not work for me if call (foo '())
13:47	cemerick	faust45: An empty seq can be a number of different concrete types. Just use a conditional. (if (seq x) y z)
13:48	faust45	cemerick: LazySeq never become EmptyList
13:49	faust45	type
13:49	faust45	cemerick: so its impossible dispatch on type
13:50	cemerick	faust45: of course it can. &(class (rest (lazy-seq [1])))
13:50	cemerick	uh, lazybot?
13:50	cemerick	,(class (rest (lazy-seq [1])))
13:50	clojurebot	clojure.lang.PersistentList$EmptyList
13:51	cemerick	faust45: you can dispatch on type, it's just hardly ever a good idea. What are you actually trying to accomplish?
13:51	faust45	clojurebot: great )
13:51	clojurebot	Titim gan éirí ort.
13:51	Raynes	cemerick: ##(class (rest (lazy-seq [1])))
13:51	lazybot	⇒ clojure.lang.PersistentList$EmptyList
13:51	Raynes	cemerick: Don't blame lazybot for your inability to understand him. He is a complex being.
13:52	cemerick	The beatings will continue until lazybot can read my mind.
13:52	Raynes	cemerick: We'd just go with &&(), but that'd blow up in our face for channels where people use languages like Ruby.
13:52	Raynes	Same with &()
13:52	faust45	cemerick: thanks will try
13:53	faust45	Raynes: why you confused about ruby use case ?
13:53	cemerick	Raynes: I figured you'd set up per-channel characters.
13:54	Raynes	cemerick: Man, we've set up so much per-channel crap that our config file is like 100 line long and it's all one big map. I'm to the point where anything that requires me to have per-channel configuration, I just disable entirely and forget exists.
13:55	Raynes	cemerick: I originally planned for lazybot to be an end-user bot, but I don't think any non-programmer in the world could figure it out at this point.
13:59	cemerick	Raynes: are there end user bots?
14:06	amalloy	lazybot ends users
14:08	jsabeaudry	Recommandations regarding a lein clojurescript plugin? lein-cljsbuild looks like it has a lot of features
14:11	jkdufair	i've been using clojure-mode and the swank-clojure lein plugin. What do i need to use my local emacs to control swank running on a remote server? an explicit slime install? will it conflict with the slime embedded in clojure-mode?
14:12	technomancy	jkdufair: yeah, manual slime install; you can use marmalade
14:12	jkdufair	super. thx.
14:12	technomancy	or if you use an emacs instance that has already jacked in, it'll already have it.
14:12	technomancy	might be nicer not to rely on that leftover copy though
14:12	jkdufair	how does that work?
14:13	technomancy	how does which work?
14:14	jkdufair	using an instance that is already jacked in? in other words, where is slime in clojure-mode? didn't see it in the sources
14:14	jsabeaudry	emezeske, Out of curiosity, why arent hooks and :jar true the default values in lein-cljsbuild?
14:14	technomancy	it's a "payload" that comes from the swank-clojure jar
14:14	jkdufair	oh fascinating. thx.
14:15	jkdufair	clever idea.
14:16	technomancy	it's insane. =)
14:23	emezeske	jsabeaudry: I don't think there's any way to enable the hooks by default
14:23	emezeske	jsabeaudry: And the plugin began life without :jar support, so when it was added, we made it default to off for backwards compat.
14:40	jsabeaudry	Ok I got hiccup and clojurescript but what about css?
14:42	fliebel	jsabeaudry: There where some DSLs, but nothing really useful afaik.
14:47	jkdufair	how do i get swank-clojure to listen on an external interface?
14:49	pjstadig	jkdufair: according to `lein help swank` it accepts port and host arguments
14:49	pjstadig	so you should be able to do something like `lein swank 6666 123.123.123.123`
14:49	jkdufair	pjstadig: thank you. wasn't aware of lein help :-O
14:49	pjstadig	:)
14:56	tscheibl	jsabeaudry: cssgen from paraseba (it's on github) is quite useful
14:57	jsabeaudry	tscheibl, Thanks I'll take a look
14:59	tscheibl	jsabeaudry: i've been using it for quite some time know... for generating css on the fly in compojure routes
15:00	tscheibl	jsabeaudry: it's better than writing css directly because it's composable and supports inline hierarchies
15:00	jsabeaudry	tscheibl, Is that so the users can modify the "skin" of the site?
15:01	tscheibl	jsabeaudry: it renders to pure css ..
15:02	tscheibl	jsabeaudry: I usually create compojure routes which set the Content-Type to "text/css" and return on the fly generated css
15:03	amro	http://hastebin.com/qihujumime.lisp I get java.lang.NullPointerException after the ex[ected pit[it
15:03	amro	expected output*
15:04	jsabeaudry	tscheibl, Yes I was curious to know in which context you would like to generate css on the fly?
15:05	tscheibl	jsabeaudry: you could parameterize it that way
15:05	tscheibl	jsabeaudry: using get query paramters
15:07	tscheibl	jsabeaudry: e.g. using hiccup: (include-css "/main.css?background=green")
15:08	tscheibl	jsabeaudry: in that case you would probably have to add nocache headers to the response
15:10	tscheibl	jsabeaudry: you could also use it to compile static css from clojure files and include these in your html
15:10	rsenior	anyone around that can talk about the build.clojure.org setup?
15:13	tscheibl	jsabeaudry: where maybe cookies would be the best way to make the skin user configurable
15:26	aphyr	tw
16:30	the-kenny	Is there a swank server for clojurescript?
16:33	technomancy	the-kenny: there's one for Javascript, but I've never used it
16:35	technomancy	the swank-clojure codebase is extremely intertwingled with Java though
16:40	the-kenny	understandable. One would most likely have to write a "real" swank server in clojurescript.
16:40	the-kenny	Also, there's the problem of compilation
16:41	clj_newb	is it possible to define defrecords Foo, Bar, s.t. (.open foo) -> returns a Bar, (.close bar) -> returns a Foo ?
16:44	TimMc	Ah, a circular dependency?
16:44	TimMc	If you use protocols... maybe?
16:44	clj_newb	yes
16:44	clj_newb	ah, so (.open foo) returns a BarInterface object, and (.close bar) returns a Foo interface object?
16:45	TimMc	Yes, although that might just net you a new circular dep. :-)
16:45	clj_newb	at the interface level ; hmm
16:46	TimMc	Is this part of your scheme to create TYped Clojure?
16:46	clj_newb	sssssh, that could get me lynched
16:46	tjgillies	how do i access functions is projectname.core namespace from lein repl?
16:46	clj_newb	This is part of building my WYSIWYG editor, I'm implementing functional zippers on my own
16:47	tjgillies	s/is/in/
16:47	clj_newb	so there are "closed/open" nodes
16:47	gtrak	tjgillies: use or require
16:47	the-kenny	Let's track clj_newb down and lock him behind 10^100 layers of parenthesis.
16:47	xian	Hi, just a quick question: When I create an uberjar with leiningen, how do I ensure that additional jars specified in :extra-classpath-dirs are available/included in the resulting uberjar?
16:47	clj_newb	and they need to return each other based on open/close
16:47	tjgillies	gtrak: thnx
16:47	brehaut	clj_newb: https://github.com/frenchy64/typed-clojure
16:47	technomancy	xian: only dependencies go into the uberjar
16:47	gtrak	tjgillies: and you can in-ns to switch to your desired namespace, but it won't be compiled until it's require'd i think
16:48	xian	technomancy: Okay, is there an easy way to add arbitrary jar files as dependency?
16:48	clj_newb	brehaut: certain looks interesting thanks
16:48	TimMc	Upload them to clojars
16:48	technomancy	xian: yes, you can publish them to s3, either in a public or private bucket
16:48	technomancy	clojurebot: repeatability is crucial for builds, see https://github.com/technomancy/leiningen/wiki/Repeatability
16:48	tjgillies	whats the syntax? i keep getting errors
16:48	brehaut	clj_newb: im pretty sure its just experiemental
16:49	tjgillies	(require 'project/core) ?
16:49	TimMc	clojurebot is pondering your request
16:49	gtrak	something like that
16:49	TimMc	tjgillies: got, not slash
16:49	TimMc	*dot
16:50	clj_newb	brehaut: yeah; but it has interesting links to read
16:50	clojurebot	Ack. Ack.
16:50	TimMc	haha
16:50	tjgillies	TimMc: thnx
16:50	TimMc	~repeatability
16:50	clojurebot	repeatability is crucial for builds, see https://github.com/technomancy/leiningen/wiki/Repeatability
16:50	clj_newb	on a complete unrelated note, is it just me; or does anyone else have an intense urge to write cocoa apps (osx, ipad) in clojure?
16:50	technomancy	ugh; no
16:51	xian	technomancy: Hmm, I would prefer another way, actually. Uploading them to s3 requires too much work just to get some external jars included in my clojure project.
16:51	technomancy	xian: have you tried it? it's much easier than the alternatives.
16:51	technomancy	unless you're ok with "works on my machine; good enough"
16:52	TimMc	xian: Do you plan on having other people use your code?
16:52	clj_newb	ah ha
16:52	clj_newb	I think what I need is extend-typ
16:52	clj_newb	e
16:53	xian	technomancy, TimMc: I just put my jars in the lib directory and building the uberjar worked fine.
16:53	xian	TimMc: Not directly. Other people will interact with the uberjar.
16:53	TimMc	clj_newb: Yep, you'll use that after the protocols and records are defined. Have you succeeded in getting both protocols defined?
16:54	clj_newb	TimMc: yeah; there's no circular dependency at the protocal level since there arne't return-type signatures in protocols
16:54	TimMc	Ah, nice.
16:55	clj_newb	is there a book that coers all this stuff?
16:55	clj_newb	I don't see it in programing clojure
16:55	TimMc	clojurebot: private jars is <reply> To depend on private jars, use https://github.com/technomancy/s3-wagon-private
16:55	technomancy	xian: if you don't care about making it work on other machines you can use lein-localrepo to turn standalone jars into real dependencies
16:55	TimMc	clj_newb: It's new in 1.3, how old is the book?
16:55	clj_newb	TimMc: says copyright 2009
16:56	TimMc	Not recent enough.
16:56	clj_newb	is any book recent enough?
16:56	xian	technomancy: Ah, I see. And yes, I only want to build the uberjar on my machine. Others won't interact with the code. Thanks for your help.
16:56	clojurebot	Ik begrijp
16:56	TimMc	I don't know.
16:57	clj_newb	ah, according to amazon, there's a new edition in april 2012
16:57	TimMc	xian: Well, just make sure you leave sufficient breadcrumbs so that you or someone else can figure out how to build it in the future.
16:57	technomancy	cool
16:58	TimMc	clj_newb: Read through the sidebar links on http://clojure.org/, you'll pick up some new stuff.
17:00	tcrawley	technomancy: in lein 2.0, are you doing away with the ability to override :library-path, :resources-path, etc? The lack of defaults in leiningen.core.project leads me to believe that
17:02	technomancy	tcrawley: you can override :resources-path and :source-path and friends
17:02	technomancy	:library-path is gone altogether; classpaths are constructed directly out of ~/.m2; so there's no more need to gratuitously copy dependencies around.
17:03	TimMc	No more ./lib?
17:03	tcrawley	technomancy: ah, cool - I see :resources-path now, thanks
17:04	gfredericks	how will negligent coworkers accidentally and irrevokably add 30mb of jars to the git repo?
17:04	technomancy	the lib/ directory was more of a historical accident from the days of M-x swank-clojure-project than something actually useful
17:04	technomancy	gfredericks: I have no doubt their ingenuity will find a way!
17:04	gfredericks	I guess there's still the build outputs
17:04	tcrawley	technomancy: right now, in Immutant we assume lib/, and add the contents to the module class path for the app. if lib/ no longer exists, we'll need to suss the classpath from lein, but I suspect that won't be difficult
17:05	TimMc	tjgillies: `lein classpath`
17:05	TimMc	tjgillies: Sorry, that was meant for tcrawley
17:05	technomancy	yup
17:05	tcrawley	TimMc: well, it will be a bit more involved that that, but I can find it from there. thanks!
17:06	technomancy	it would be easy to write a copy-deps plugin, but there's just no need to have it built-in
17:06	TimMc	whoa
17:06	TimMc	I just realized that a meter is basically a baker's yard
17:07	brehaut	welcome to the future TimMc
17:07	TimMc	high on the metric system
17:08	TimMc	Sorry. ANYWAY.
17:08	brehaut	the initial euphoria should pass fairly quickly. it'll seem very ordinary in no time
17:09	gfredericks	ha: TIME. When are we switching from years to kilodays?
17:09	TimMc	technomancy: I assume lein2 will be able to use the vast majority of project.clj files out of the box?
17:10	AimHere	Then it stops being fun. You're just thinking in metres, kilometres, kilogrammes, just in order to feel normal each day.
17:10	TimMc	gfredericks: I already say things like "I'll be back in about a metric hour" just to mess with people.
17:10	clj_newb	should I prefix protocols with I or P, i.e. IFoo or PFoo?
17:11	TimMc	clj_newb: From the Java side, they just look like regular interfaces, right?
17:11	TimMc	I haven't worked with protocols yet.
17:12	clj_newb	I do not know enough about clojure to know.
17:17	lucian	clj_newb: i've seen them prefixed with P. i wouldn't prefix them with anything, though
17:19	jcrossley3	clj_newb: i think the context in which a protocol is used makes the prefixes superfluous. i don't even like using 'em in java, myself.
17:19	hiredman	my irc client only shows me timestamps in kiloseconds since midnight
17:20	TimMc	Which midnight, O /ignore'ant one?
17:20	TimMc	(UTC would be best.)
17:21	jsabeaudry	Anyone knows how to tell cljsbuild to look into lib so it can find cljs libraries such as pinot?
17:22	clj_newb	hmm; I like my hungarian notation.
17:22	TimMc	clj_newb: As long as it's Apps Hungarian.
17:28	emezeske	jsabeaudry: The missing support for that is a bug (that I plan to fix this evening)
17:28	jsabeaudry	emezeske, Sweet! I'll use cljs-watch for the time being
17:30	technomancy	TimMc: yep, the main blocker will be plugins that use Leiningen functions that have moved.
17:32	jcrossley3	clj_newb: TimMc: i don't even think Simonyi uses hungarian notation any more. :)
17:59	the-kenny	emezeske: Nice to hear this. I wated to report this bug today :)
17:59	the-kenny	s/wated/planned/
18:44	emezeske	jsabeaudry, the-kenny: I'm trying to decide how best to fix the lib/ problem. I wonder if everything in :dependencies should be accessible to the cljs project, or if maybe I should add a new :dependencies option to the :cljsbuild config
18:44	Raynes	emezeske: http://blog.raynes.me/blog/2012/02/01/i-code-with-things-and-stuff/ I gibs vim love (and link to your copy of paredit.vim).
18:46	jsabeaudry	emezeske, I would tend to make everything in :dependencies and :dev-dependencies available
18:46	the-kenny	Yup, me too.
18:46	the-kenny	cljsbuilds own :dependencies would lead to a problem with hybrid jars which contain .clj and .cljs (like cljs-uuid)
18:48	emezeske	I guess my only worry is that cljsbuild depends on clojure 1.3.0
18:48	emezeske	What would happen if the project used 1.2.x?
18:48	emezeske	Right now, the plugin uses leiningen's eval-in-project to always use 1.3.0
18:49	emezeske	I'm not a jar expert, but it seems like conflicts could arise (?)
18:49	emezeske	Raynes: Awesome, I'll have to give that a read-through!
18:50	technomancy	emezeske: yeah, declaring a direct dependency on a project that requires 1.3 will cause issues. you would have to run cljsbuild code inside eval-in-project as well
18:51	emezeske	technomancy: That makes sense. I'm trying to figure out how to allow the cljs code to have jar dependencies
18:52	emezeske	technomancy: right now it uses eval-in-project and does not assoc in anything from the parent
18:53	technomancy	emezeske: wouldn't it make sense to just say that projects that have clojurescript components can't use 1.2?
18:53	emezeske	technomancy: Hmm, that seems fair. I doubt anyone that uses cljs is not up to 1.3 by this point
18:54	emezeske	the-kenny, jsabeaudry: Informal survey: are your projects using clojure 1.3?
18:54	TimMc	I'd liek to maintain import-static from old contrib. Any thoughts on how to do this?
18:55	TimMc	(Should I just fork and delete everything else?)
18:57	the-kenny	emezeske: Yup
18:59	emezeske	the-kenny: Okay, thanks
19:04	cmajor7	what space does "loop/recur" consume? heap?
19:05	TimMc	cmajor7: constant space
19:05	TimMc	Oh, you mean where does it allocate locals?
19:05	cmajor7	yep. where does it keep the "memories"
19:05	TimMc	?
19:06	TimMc	As I understand it, the JVM basically puts everything in the heap.
19:06	cmajor7	well… recursion (unless it is "tail") keeps them on the stack
19:07	cmajor7	ok.. so loop/recur saves the "recursion" point in heap
19:07	cmajor7	right?
19:08	hiredman	it doesn't consume space, that is the point
19:10	cmajor7	hiredman: I see, so it is in a way tailed..
19:10	cmajor7	like:
19:10	cmajor7	fac( N ) ->
19:10	cmajor7	fac ( N, 1 ).
19:10	cmajor7	fac ( 0, Holder ) ->
19:10	cmajor7	Holder;
19:10	cmajor7	fac ( N, Holder ) ->
19:10	gfredericks	cmajor7: that's why loop/recur exists
19:10	cmajor7	fac( N - 1, N * Holder ).
19:10	cmajor7	(erlang)
19:10	hiredman	~pastebin
19:10	clojurebot	Excuse me?
19:11	hiredman	clojurebot: paste you jerk
19:11	clojurebot	No entiendo
19:11	hiredman	~paste
19:11	clojurebot	paste is gist
19:11	gfredericks	cmajor7: because the native JVM functions won't do tail recursion
19:11	hiredman	~gist
19:11	clojurebot	gist is forget paste
19:11	amalloy	hiredman: he can't remember "paste is gist.github.com" because the . ends the factoid
19:11	gfredericks	clojurebot: paste is gist,github,com
19:11	clojurebot	'Sea, mhuise.
19:12	hiredman	amalloy: that is not true
19:12	hiredman	~forget paste \|is\| gist,github,com
19:12	clojurebot	I forgot that paste is gist,github,com
19:13	amalloy	hiredman: okay. i'd be delighted to learn the right way to teach him, then, becase at least three times i've seen someone teach him gist.github.com and he parrots back just gist
19:13	cmajor7	gfredericks: right. so loop/recur pair takes an existing state, creates a new [single] stack frame, passes the state to that stack frame, and leaves the past to GC?
19:13	hiredman	amalloy: most likely because some taught it 'paste is gist'
19:13	hiredman	~gist
19:13	clojurebot	gist is https://refheap.com/
19:13	hiredman	~paste
19:13	clojurebot	paste is http://gist.github.com/
19:13	hiredman	~paste
19:13	clojurebot	paste is gist
19:13	hiredman	~paste
19:13	clojurebot	paste is gist.github.com
19:13	hiredman	~paste
19:13	clojurebot	paste is http://gist.github.com/
19:14	hiredman	etc
19:14	amro	any idea why I'm getting a NullPointerException with this macro? http://hastebin.com/qihujumime.lisp
19:14	hiredman	amro: to start with docstrings go before arg lists
19:15	hiredman	to end with, look at the macroexpansion
19:15	gfredericks	cmajor7: I don't know the GC details but it certainly doesn't accumulate space like explicit recursion does
19:16	amro	hiredman: yes, there's an extra pair of () around it
19:16	amro	I don't know how to get rid of it
19:16	hiredman	extra how?
19:16	hiredman	you have a for
19:16	amro	((print "a")) instead of (print "a") for instance
19:16	hiredman	for is list/seq comprehension, so the result is a seq
19:17	cmajor7	gfredericks: that I see from the documentation. I was wondering the under the hood state of things.. it seems that it only keeps a single stack frame at a time..
19:17	amro	how do I flatten just the topmost seq then? and have it return (print "a") (print "b") etc
19:18	weavejester	You probably want a (do ~@(for ...))
19:18	weavejester	But using a macro to do this is pretty strange
19:18	weavejester	Is it just for practise?
19:19	amro	weavejester: that doesn't work, I tried it. I get Var clojure.core/unquote-splicing is unbound.
19:19	amalloy	also, drop the # in b#. it will just confuse people (mostly you)
19:19	amro	I dumbed down the macro so I can figure out what's wrong
19:19	weavejester	You probably forgot the beginning backtick
19:19	weavejester	In total it should be `(do ~@(for ...))
19:19	amalloy	&(let [body '(a b)] `(do ~@(for [b body] `(print ~b))))
19:19	lazybot	⇒ (do (clojure.core/print a) (clojure.core/print b))
19:20	amro	that's it, thanks
19:20	amro	I wasn't sure how to combine ` with ~@
19:20	weavejester	~ and ~@ go inside `()
19:20	clojurebot	Gabh mo leithscéal?
19:21	weavejester	It's like string interpolation in Ruby, Bash or Perl
19:21	weavejester	"hello $foo" is kinda equivalent to `(hello ~foo)
19:21	amro	amalloy: b# was part of the expanded macro when I first wrote it
19:21	weavejester	Except you're using data structures instead of strings
19:22	amalloy	personally i slightly prefer (cons `do (for ...)) to `(do ~@(for ...)), but i don't have a compelling argument
19:23	amalloy	i guess it forces me to keep in mind that really macros are functions for building lists, not "magic templates"
19:23	weavejester	Not just lists in Clojure ;)
19:23	gfredericks	the magic rose ~@
19:25	amalloy	weavejester: yeah, i know. having a macro expand to just an integer or a string is pure magic
19:26	weavejester	amalloy: Hiccup makes does a lot with strings :)
19:27	amalloy	i feel like there must be very few cases where (html ...) expands to a string, though
19:27	weavejester	Yeah, it only expands to a string if there are no variables in the mix
19:27	weavejester	Does anyone else find that search engines are surprisingly good nowadays?
19:27	weavejester	I mean, I take them for granted
19:28	amalloy	i guess that's only half-true, because (html [:div foo bar]) expands recursively to something like (str "<div>" (html foo) (html bar)], and then foo and bar might be literal strings
19:28	weavejester	But even using them everyday sometimes they manage to match queries to the right page with very little info
20:05	amalloy	technomancy: make is pretty good. i'd definitely prefer it to ant, for example
20:06	technomancy	high praise
20:07	amalloy	yeah yeah
20:07	technomancy	I guess in my mind make is tainted by autotools
20:07	technomancy	guilt by assosiation
20:07	amalloy	yeah, autotools are something i cannot fathom at all. maybe it's great, but it is so bewildering
20:07	brehaut	i can only presume that once upon a time, it didnt seem like a bad idea
20:08	brehaut	and then it metastasized
20:08	technomancy	the fact that people who seem otherwise intelligent put up with them makes me think that the alternative of doing that kind of stuff by hand is just too horrible to comprehend?
20:08	technomancy	it is beyond my feeble imagination
20:36	TimMc	Any tips on testing namespace-manipulating functions?
20:37	TimMc	I don't want to contaminate my test namespace. Currently trying to write a macro that will evaluate its contents inside a temporary namespace.
20:39	technomancy	TimMc: copy what slamhound does
20:39	technomancy	each run generates a throwaway ns named after a gensym
20:41	TimMc	I think I finally have it, thanks.
20:41	TimMc	But I'll look at slamhound for sure.
20:42	TimMc	I ran a test in my REPL that worked differently line-by-line vs. as a single 'let form.
20:59	jcromartie	so I'm digging the REST vibe right now
20:59	jcromartie	and I am getting this idea that you could actually build a perfectly RESTful API without actually setting up routes for resources
21:00	jcromartie	i.e. by leveraging hypermedia and continuation-style callbacks of some sort
21:01	jcromartie	like, in your server-side API, you return a resource where the actions called by verbs are just closures tied to unique URLs
21:01	jcromartie	I hope that's not too ASP.NET
21:09	seancorfield	jcromartie: do you have example code somewhere? how do you map the urls to actions?
21:10	jcromartie	I'm working on it :P
21:10	jcromartie	let me whip up an example
21:10	brehaut	jcromartie: i dont see any reason why that couldnt be restful; nothing about rest requires you to have stable URLs
21:11	brehaut	(stable in terms of the app configutarion)
21:11	jcromartie	brehaut: yes, that's the point
21:11	jcromartie	well there do need to be stable entry points
21:11	brehaut	sure
21:11	jcromartie	I think I basically just came up with Seaside for APIs
21:11	jcromartie	but not so fancy in the use of continuations
21:12	brehaut	jcromartie: yeah
21:13	brehaut	jcromartie: as long as you keep the old URL callbacks around in case the client passes you an older version of the state, then it should be fine
21:14	jcromartie	but deleting the non-idempotent verbs when they are executed
21:14	jcromartie	that has the added benefit of not eve being able to accidentally DELETE something twice
21:17	martinklepsch	what is the reason behind "acc" as loop binding name?
21:17	brehaut	accumulator
21:19	brehaut	which i guess is following on from the registers of the same name
21:19	martinklepsch	ok
21:22	martinklepsch	I don't get how acc is being bound to the new value in the (recur) example here http://clojure.org/special_forms
21:22	martinklepsch	could anyone explain me that?
21:23	gfredericks	martinklepsch: the loop contains two bindings, so in the call to recur the second argument gets bound to acc
21:24	martinklepsch	okay so when i have 3 bindings I'd have 3 arguments to recur etc?
21:24	brehaut	yes
21:24	gfredericks	exactly
21:25	martinklepsch	makes sense...
21:42	wiseen	is there a library for serializing things to clojure Data that's more flexible than (prn-str x) ... eg. I would like java.util.Date to be serialized and some other primitives (URI)
21:43	gfredericks	wiseen: print-dup might be what you want?
21:46	wiseen	clojurebot ,(doc print-dup)
21:47	ibdknox	hola
21:48	Raynes	ibdknox: stfugoaway
21:48	ibdknox	Raynes: h8.
21:51	TimMc	wiseen: print-dup is a multimethod you extend.
21:57	blakesmith	Can anyone recommend a good clojure memcache library?
22:05	jcromartie	why did I just write a JSON library
22:05	gfredericks	there's nothing funner
22:05	jcromartie	this sort of thing happens
22:06	TimMc	It really does.
22:06	jcromartie	https://gist.github.com/3872b7bfd382ef706bd9
22:07	jcromartie	I think it was because I didn't feel like opening project.clj
22:07	jcromartie	and adding the dependency
22:07	ibdknox	that's so much slower :p
22:08	jcromartie	nerds will go to great lengths to be lazy
22:08	brehaut	that sums up haskell
22:11	TimMc	pffft
22:12	TimMc	I can't remember why I ended up dropping clj-json in favor of cheshire...
22:15	ibdknox	TimMc: everyone's doing it :p Raynes made me change it in Noir
22:15	ibdknox	something to do with "more features" and "just as fast"
22:21	TimMc	Oh! clj-json gave me string keys, I wanted keyword keys
22:23	TimMc	No, it was coercions not being marked :dynamic, that was it.
22:23	TimMc	Looks like that one is fixed.
22:55	Raynes	ibdknox: The bad part is that a coworker seems to be the maintainer now.
22:55	ibdknox	Raynes: of clj-json?
22:55	Raynes	Making everybody switch to cheshire is probably not a good career move.
22:55	ibdknox	lol
23:00	seancorfield	how many json libraries do we have? and what's wrong with clojure.data.json?
23:00	TimMc	seancorfield: What's wrong with it is that I didn't know it existed. :-P
23:04	seancorfield	formerly clojure.contrib.json
23:05	ibdknox	seancorfield: it's not very fast I thought
23:05	ibdknox	at least not compared to something using jackson
23:06	seancorfield	i guess it depends whether it's "fast enough"
23:07	ibdknox	format conversions are one of those things that should just be as fast as possible
23:07	seancorfield	but i'd prefer we all worked to improve the standard clojure.* whatever libraries than proliferate incompatible alternatives :)
23:07	brehaut	ibdknox: unless its xml-rpc
23:07	brehaut	ibdknox: that might encourage someone to want to use it
23:07	ibdknox	lol
23:09	TimMc	seancorfield: Speaking of which, I'm trying to adopt import-static right now.
23:10	TimMc	It currently works by making macros, so you can't do (import-static '(java.lang.Math sqrt)) (map sqrt (range 10))
23:10	TimMc	...but I don't know what my chances are of getting my version blessed.
23:11	seancorfield	:)
23:11	seancorfield	well, after that drive-by pot-stirring, i'm off to watch TV and drink wine... or whisky perhaps?
23:12	TimMc	heh
23:12	TimMc	What is the beverage of choice of trolls? :-P
23:14	Raynes	seancorfield: I see no real point in improving clojure.* if a non-contrib library is better and significantly faster. You can't clean shit.
23:15	Raynes	And that came out a lot more rude to whoever the original author of that library is than I meant it to be.
23:15	brehaut	Raynes: but you can dunk it in varnish
23:15	Raynes	My point is, if the library can't be fast, why support it in the first place?
23:15	Raynes	The only reason cheshire can't be a contrib library (or clj-json for that matter) is because it relies on a fast Java library.
23:16	TimMc	The official libs also have the stigma (deserved or not) of not being able to move quickly.
23:16	Raynes	But really, I hate the distinction between 'contrib' libraries and libraries that people make.
23:16	seancorfield	the guys on mythbusters proved that you _can_ polish a turd, btw
23:16	TimMc	Raynes: The contribs are just the officially blessed libs, yeah?
23:17	Raynes	It seems to me that contrib is only useful for political purposes and for people who really like XML and terrible JIRA issue managers.
23:17	brehaut	Raynes: i dunno, i think contrib as a 'this project has proven to be great, lets promote it into a more visible tier' is valuable; eg core.logic
23:17	Raynes	That's kind of my point.
23:17	Raynes	The JSON lib isn't great. It's slower than ever other library.
23:18	Raynes	But we should work on it because… it's officially sanctioned and written in pure Clojure?
23:18	Raynes	inb4 itisn'tpureclojurebecauseitcallsouttojava
23:19	jeremyheiler	If a project is blessed, doesn't that immediately raise the barrier of entry to support it, as opposed to just being a popular project that doesn't have the same contributor rules as clojure porper?
23:19	seancorf	there are discussions around using external dependences in some contrib libs... it might happen...
23:19	jeremyheiler	proper*
23:19	seancorf	and the new process is meant to be a lot more streamlined and faster to evolve code
23:20	Raynes	No, because being officially blessed means you have to go through hell to actually contribute.
23:20	Raynes	Not that they don't have excellent reasons for the hellish procedure.
23:20	seancorf	but the important distinction is a legal one: contrib libraries are protected under the same license / IP as clojure itself - which is of concerns to a lot of companies
23:20	Raynes	Some of them, anyways.
23:20	Raynes	Yeah yeah yeah, I know.
23:21	Raynes	Not a lawyer.
23:21	Raynes	Thankfully.
23:21	seancorf	and to be honest Raynes the process really isn't hellish :)
23:21	Raynes	If we're talking about barrier to entry, I'd be happy to hear of a single point in the favor of non-hellish.
23:21	seancorf	i ended up maintaining java.jdbc without much fuss, because i needed contrib.sql running on 1.3
23:23	seancorf	there are a LOT of people with signed CA's on file which means a large pool of people who can submit patches
23:24	Raynes	But we were talking about barrier to entry, right?
23:24	seancorf	all the open source projects i know have a similar barrier to entry
23:24	seancorf	you have to sign a CA and follow the patch process
23:24	cmajor7	"recur special form can also be used as the last call in a function to return to the beginning of that function with new arguments" => would this be a common use? or the one to avoid? ##(defn recursive ([number] (recursive number 1)) ([number factorial] (if (zero? number) factorial (recur (- number 1) (* factorial number)))))
23:24	lazybot	java.lang.SecurityException: You tripped the alarm! def is bad!
23:24	Raynes	I sure don't know of a lot of them.
23:25	Raynes	But I wasn't arguing against the CA.
23:25	Raynes	Like I said, I'm not a lawyer.
23:25	jeremyheiler	seancorf: Is a maintianer of a contrib allowed to process patches at their own pace? So, for example if a popular library with an active community is blessed, that shouldn't hurt the project in anway, right?
23:25	jeremyheiler	If*
23:25	jeremyheiler	sorry, Is*
23:25	Raynes	seancorf: As a lib maintainer, are you allowed to accept patches and issues on Github?
23:25	jeremyheiler	(sans a CA agreement form all)
23:26	seancorf	no pull requests allowed
23:26	Raynes	I consider JIRA a massive barrier to entry, dismissing all the CA stuff.
23:26	jeremyheiler	^agreed.
23:26	TimMc	seancorf: Ouch.
23:26	Raynes	I consider JIRA a massive barrier to anything.
23:26	seancorf	patches via JIRA are the acceptable way
23:26	seancorf	it's because of legal traceability of copyright
23:26	TimMc	I'm not going to even bother trying to get this contrib I'm maintaining blessed.
23:26	Raynes	Well, at least they've got their asses covered. shrug
23:27	Raynes	Really, really well.
23:27	seancorf	like i say, just like all the other open source projects that corporations feel comfortable using
23:28	jeremyheiler	For core, I think the CA and legal stuff works really well. That's important. But I think it really makes it undesirable to have a library blessed into contrib if it wasn't specificlly written to be there in the first place.
23:28	seancorf	when i worked at macromedia / adobe i had the "pleasure" of going thru a license audit on a large project
23:28	TimMc	seancorf: Ah, you're saying that this is effectively due to pressure from corp.s that want to use these projects?
23:28	Raynes	I'm fine with companies not using my projects if I get to maintain them in a sane was a resut.
23:28	Raynes	result*
23:28	seancorf	yeah, without that stuff, many corporations cannot use an open source project
23:28	seancorf	i want clojure to be usable by such companies so i'm happy to comply with the process
23:29	Raynes	The way I feel at this point is that I just hope nobody puts any libraries I like into contrib so that, if I ever have to contribute to them, I don't have to go through all the nutty crap involved. That's just me though.
23:29	TimMc	seancorf: I don't see why you can't get the same traceability via Github permissions.
23:29	nuclearsandwich	Raynes: agreed
23:29	Raynes	TimMc: Apparently if you delete your account, your name disappears.
23:30	TimMc	>_<
23:30	seancorf	TimMc: because you have to go back thru the entire repo history and ensure that all committers have signed CAs on file
23:30	TimMc	But the commits are still there!
23:30	TimMc	seancorf: Not hard. There is rarely a ton of committers.
23:30	Raynes	It's probably only a matter of time before they have the code in git repos hosted on their server, just in case. :p
23:31	TimMc	seancorf: Although I guess someone could lie and submit under someone else's name?
23:31	Raynes	You could probably send in a fake CA and submit a patch under that. Not sure what would happen. Damn not-being-a-lawyerness.
23:32	Tcepsa	cmajor7: I believe that is a common use
23:32	seancorf	the CA is a legally binding document - so it protects the project
23:32	jeremyheiler	I don't see why accepting a pull request can't involve a core committer checking the user for a CA first. I Imagine that is done in JIRA anyway?
23:32	Raynes	You can only get a Jira account if you've been sanctioned by a team member.
23:32	seancorf	jeremyheiler: because then the burden is on core which isn't fair to the project
23:32	Raynes	It's admittedly different.
23:32	jeremyheiler	Ah, ok.
23:32	Raynes	But...
23:33	seancorf	having been thru the other side of this at a corporation, i can only say that this is necessary for corporation adoption of clojure and its set of sanctioned contrib libraries
23:33	arohner	seancorf: "this" being CAs. JIRA + patches seems to be more of an implementation detail, IMO
23:34	arohner	I can imagine Github having a permissions model that would make this painless
23:34	Raynes	Let the record stand that it is not the CA that I have a problem with.
23:34	seancorf	yeah, we know you don't like JIRA :)
23:34	Raynes	It is the fact that we're only allowed to use a small subset of what Github offers.
23:34	Raynes	You might as well host these repositories with gitweb.
23:35	TimMc	Oh, fun with macros: actual: (not (number? (. java.lang.Math (sqrt 3.141592653589793))))
23:35	cmajor7	Tcepsa: thank you. you mean it is used commonly even though it can be accomplished with "loop/recur"?
23:36	seancorf	you can use the full range of github - you can fork clojure, work on it any way you want...
23:36	emezeske	jsabeaudry: I just released lein-cljsbuild 0.0.10, which pulls in the host project's :dependencies and :dev-dependencies. Let me know if it works for you!
23:36	Raynes	seancorf: I'm making sure I'm clear on this. You know I don't like Jira, right?
23:36	seancorf	but if you want a patch accepted, you have to put it in a JIRA ticket as a patch :)
23:36	Raynes	You can pull from a gitweb repository and work on it anyway you want.
23:36	Raynes	And it is the exact same thing.
23:36	TimMc	It's not JIRA that bothers me, it's patch-formatted contributions.
23:37	seancorf	i agree github's "free-for-all" workflow is more convenient
23:37	Raynes	seancorf: All a Github fork is is a copy of a repo under your name. It isn't anything special that you need Github for. If that was the full range of Github, I'd probably just use bitbucket and hg.
23:37	seancorf	but i also understand that corporate concerns mean a tighter control on IP and contributions
23:37	Raynes	;)
23:38	Raynes	Yeah, we know you're worried about corporate concerns. :)
23:38	seancorf	i maintain clj-time and work on congomongo too and it's nice to be able to accept random pull requests but that also means those libraries can't be used by corporations that have license audits :)
23:39	jeremyheiler	All I'm saying is that "the process" might just make it less desirable to want a useful lib be blessed into contrib. Wether tha tis important or not, i don't know.
23:39	jeremyheiler	(from a maintainer's and community perspective)
23:40	Raynes	That's where I'm at right now.
23:40	seancorf	jeremyheiler: understood - and several folks have raised that issue on clojure and clojure-dev MLs over the last year or so (i'm sure it came up before then too but i wasn't around then :)
23:40	Raynes	But like I said, that's just how I feel. I understand the justifications and I know that my bitching wont change anything. Doesn't mean I have to like it.
23:40	seancorf	it's ok, we don't mind being a "shoulder to cry on" about it :)
23:41	Raynes	You mean you. :p
23:41	seancorf	and, yeah, for the record, i wish we could accept pull requests but it is what it is
23:42	Tcepsa	cmajor7: Yes; I believe that's the intent of providing a mechanism to return to the beginning of the current function; it prevents you from having to put in a redundant loop statement if you're essentially doing a tail-call.
23:42	Raynes	The important thing is that we're all free to do whatever we want because Clojure is open source. If we don't want to put our libraries in contrib then we certainly don't have to. Don't have to use the ones that are there either, but the contrib process wouldn't stop me from using a good contrib library. clojure.data.json doesn't seem to be one of them though.
23:42	jeremyheiler	I should probably cancel mine then. (I submitted a patch as well, though)
23:42	TimMc	jeremyheiler: Cancel which?
23:42	jeremyheiler	the pull request.
23:42	TimMc	heh
23:43	jeremyheiler	yeah
23:43	Tcepsa	cmajor7: Put another way, that's how you can approximate tail-call optimization even though the JVM doesn't support it directly.
23:43	jeremyheiler	Raynes: compeletely agree. And it's simple to fork a contrib lib and modify it for your own needs until a patch is approved.
23:44	Tcepsa	cmajor7: Instead of calling your function again and pass it the new arguments, you call recur and pass IT the new arguments.
23:44	kilborn	Hi, new to clojure, I'm trying to figure out an idiomatic way to do the equivalent of mutating a closure bound variable? I have a function which recurs, and I need it's behavior to be controllable from outside it's scope. Global variables are not the right way... Suggestions?
23:44	Raynes	That's generally what I've been doing.
23:44	Raynes	Except the sending a patch part. I have to really care to do that.
23:45	Raynes	But that's pretty selfish and a habit I intend to break.
23:45	jeremyheiler	haha
23:46	cmajor7	Tcepsa: I see.. so the "loop/recur" actually equals "defn/recur"?
23:46	Tcepsa	kilborn: This is a shot in the dark, but have you looked at using an "agent"?
23:48	kilborn	Tcepsa: I thuought about it (message-passing seems to suggest itself), but I hoped there's a simpler way then going all erlang and stuff...
23:49	kilborn	I'm pretty close to constructing the function by passing an atom map into it, then pinning the atom symbol on the function's metadata, but that feels too complicated as well.
23:50	dnolen	kilborn: what you're trying to do doesn't sound all that idiomatic. but you can do it.
23:50	Tcepsa	cmajor7: I am not certain what's actually happening under the hood (I wouldn't be at all surprised if there was some subtle-but-important difference between the two) but that understanding will probably serve you pretty well. I think of them as being two separate things, but as far as how you go about using them, they are very similar. (In other words, it looks like it but I'm not familiar enough with the details to say "Yes
23:50	Tcepsa	absolutely" ~wry grin~)
23:50	dnolen	kilborn: (let [x (atom nil)] (defn foo [] ...))
23:51	flazz	i'm doing bit operations on an integer, is there a way to not have it convert to a long?
23:52	kilborn	dnolen: hey, you're the core.logic guy! tips hat. But then I keep everything in outer namespace, and it feels like it should be encapsulated inside the function...
23:52	dnolen	kilborn: it's not visible, you've create a lexical scope
23:53	dnolen	created
23:53	Tcepsa	kilborn: Also, at the hazard of looking like a complete idiot, I ask "Could you use a namespaced variable?"
23:53	Tcepsa	Nevermind, you just answered
23:53	kilborn	dnolen: well, if I do it exactly like you suggest yeah, but then how to I modify the atom from say the REPL? i need a symbol in my hand
23:53	kilborn	s/todo/
23:54	arohner	cmajor7, Tcepsa : recur goes "up" to the nearest recursion point, which is either a loop, or the defn
23:54	cmajor7	Tcepsa: thanks. in clojure core source I see "loop/recur", hence I suspect it outperform "defn/recur"… the thinking is "loop" just creates a "point/address" of recursion, while "defn" might be a bit more expensive. especially a arrity matching. e.g. (defn fn ([n] (fn n 1)) ([n accum] (…)))
23:54	Tcepsa	kilborn: If you have a "starter function" (no idea what it'd really be called) that creates an atom and passes it to your recurring function and also returns the atom, then you could catch the return value and modify it in your REPL.
23:56	dnolen	kilborn: it sounds like you're doing something strange :) probably need more context
23:56	kilborn	Tcepsa: True, and that's where I was leaning, but then if my function has 2 lines in it, It feels like i'm balancing dolphins on my nose while simultaneously practicing my limbo skills
23:56	Tcepsa	kilborn: (assuming that it starts the recursive function in a separate thread, but the way you've been talking about it strongly implies that it is in a separate thread from e.g. the REPL)
23:56	kilborn	Dnolen: gladly. you've heard of overtone?
23:56	dnolen	kilborn: yep
23:57	kilborn	dnolen: great. really basic use case. I have a function which takes in a list of chords, chooses one randomly, and then reschedueles itself to play the next one in say 1000 ms
23:58	kilborn	dnolen: it's all working nicely, but now I want to change the chord choices (say I move to the chorus in a piece, whatever). with closures and set! , or objects and setters, this would be very natural, but with immutable data I can't find the idiom
23:59	dnolen	kilborn: not sure why an atom at the top level your ns doesn't perfectly solve the problem.
23:59	Tcepsa	cmajor7: I'm not sure, but based on what arohner said I'm guessing that when it enters a function it also places a point/address of recursion. Arity isn't a problem--just think of functions defined with different arities as different functions. Whichever one the recur is in is the one that will be recurred to. (i.e. you can't recur from inside a function that takes two arguments to the inside of a function of the same name that
23:59	Tcepsa	takes one argument; you'd have to use trampoline for that)