#clojure – 2015-10-04

2015-10-04

00:19	python476	turns out after 1 hour, java throws a ThreadDeath exception.
04:04	roelof	Hello, I have to put a initial value here (reduce (fn [counter] (inc counter)) [1,2,3]) but where do I put it ?
04:10	expez	roelof: this is a good site to help answer such questions: https://clojuredocs.org/search?q=reduce
04:11	expez	not only do you get the docstring, but quite a few examples answering common questions as well as common gotchas
04:12	roelof	expez: thanks, I have read them and as far as I understand it , it must be this : (reduce (fn [counter] (inc counter)) 0 [1,2,3])
04:13	roelof	but then I see this error message : clojure.lang.ArityException: Wrong number of args (2) passed to: core/eval6230/fn--6231
04:13	expez	roelof: you are right, that's the right place ot put the seed value, but that's not related to the error you're getting
04:13	expez	roelof: the function passed to reduced must take two arguments, yours only takes one
04:14	expez	,(reduce (fn [counter _] (inc counter)) 0 [1,2,3])
04:14	roelof	thanks I will hit the book why counter needs two arguments instead of 1
04:14	clojurebot	3
04:15	expez	roelof: reduce reduces multiple values two a single value
04:16	expez	roelof: to do that the reducing argument considers two things: the accumulated value so far, and the value of the next element in the input sequence
04:16	expez	the reducing function*
04:17	expez	,(reduce (fn [accumulator n] (+ accumulator n)) [1 2 3 4])
04:17	clojurebot	10
04:17	expez	the final value is the value in the accumulator
04:17	expez	once all inputs have been consumed
04:18	roelof	thanks for the explanation
04:19	roelof	finnaly that challenge on 4clojure solved. Can this solution be improved : (fn [list] (reduce (fn [counter _] (inc counter)) 0 list))
04:20	expez	I take it the exercise is to re-implement count?
04:20	roelof	expez: yes, I try to solve that exercise
04:22	expez	I think using reduce is a fine choice
04:23	roelof	expez: so the solution cannot be shorter ?
04:24	expez	,(reduce #(+ %1 %2) (range 10))
04:25	clojurebot	45
04:26	expez	I thought this might work: (reduce #(inc %1) 0 (range 10)) but it doesn't :p
04:27	expez	so no, I don't think you can make it much shorter
04:30	roelof	expez: thanks, now the next challenge, make Fibonacci Sequence. so again a nice one to think how to solve this. First thought something like map
04:31	luma	i guess you could (reduce + (map (constantly 1) list))
04:34	expez	(while true (future 1)) is fine, right? I'm not leaking any resources?
04:40	amalloy	if you don't mind forkbombing yourself
04:40	amalloy	this spins up threads as fast as your OS is capable of
04:41	expez	amalloy: obv that doesn't happen in practice, I tested this to find out if I leaked memory when I didn't use future-cancel or ever retrieve the value of the un-interesting futures.
04:42	expez	running the code above at the repl seems to only produce a cpu load, not a memory load
04:43	amalloy	you don't leak anything permanent, but whether your thread demand outpaces supply is a matter of luck and/or system power
04:44	expez	great, thanks
06:05	visof	hi guys
06:06	visof	how can i convert this haskell (fmap (fmap f) z) to clojure? (fmap #(fmap f %) z) ?
06:08	expez	,(map (partial map inc) [[1 2] [3 4]])
06:08	clojurebot	((2 3) (4 5))
06:08	expez	visof: ^
06:09	expez	Is there a general version of subvec which works seqs?
06:12	djcoin	visof: in which order are your argument?
09:04	ob-sed	hey this gu in ##hardware is complaining clojure uses up too much ram
09:13	ob-sed	i told him to shut his mouth the hell up
09:13	ob-sed	his name is crocket
09:15	oddcully	><((((*>
09:19	taylanub	ob-sed: that doesn't sound like a very friendly thing to do
09:19	ob-sed	taylanub: yeah but he's been saying the same thing for an hour, like a broken record, how:
09:19	ob-sed	"<crocket> I just wanted to say that "RAM is cheap" is not an excuse for thinking that it's ok to consume 160MB for a daemon whose only task is to send an HTTP request regularly."
09:21	oddcully	and then you /ignore:d it, right?
09:25	crocket	RAM is not so cheap.
09:25	taylanub	do we have a !mods command? shall I invoke it?
09:26	crocket	If RAM was cheap, it should be ok for every small linux daemon or every kernel driver to consume 160-250MB.
09:26	crocket	Then, linux won't fit in 16GB RAM.
09:26	taylanub	ob-sed: crocket: get a room and leave the channel alone
09:27	taylanub	(I'm new here but I assume this is common sense.)
09:27	crocket	taylanub, you from ##hardware?
09:30	crocket	I came here to say it because some people in this channel said as if every program could afford to consume hundreds of MB. This is physically impossible.
09:40	Bronsa	ob-sed: clojure doesn't fit all usecases, I wouldn't use it in memory-constrained embedded devices.
09:40	Bronsa	also please don't bring issues from other channels here
09:40	wasamasa	some people are having a hard time just accepting that java was made for running a single application on a server
09:44	wasamasa	ob-sed: generally, the channel to take such things to is #freenode
11:17	gfredericks	okay I might make a library that's a stupid datastore where it just appends edn events to a file and keeps a reduction of all the events in memory
11:17	gfredericks	unless somebody tells me it already exists
11:27	gfredericks	I think I should probably name it "webscale"
11:32	sakalli	join #commonlisp
11:32	sakalli	sry ;)
12:12	xtreak	Hi, what is the difference between require and :require. require needs the vector to be quoted and :require doesn't need it. Saw them used interchangeably. Any difference?
12:37	luxbock	xtreak: require is the function that loads a namespace from the classpath, and because the namespace hasn't been loaded up yet you need to quote its argument as the symbols it uses haven't been defined yet
12:39	xtreak	Thanks. Why do some tutorials use :require keyword for loading libraries. Any difference or is it a matter of preference?
12:40	luxbock	xtreak: so the `ns` that's used in the ns-declaration of a file is a macro, and it uses kind of a mini-DSL to create and reference other namespaces, and :require is part of that mini-DSL
12:40	luxbock	it gets translated to calling `require` in the end
12:41	luxbock	I don't know why it uses :require instead of just the symbol, probably because then it it would be even more confusing why one needs the quote and the other doesn't
12:42	luxbock	the reason you don't need to use quote with :require is because it's a macro so the symbols inside don't get evaluated
12:43	luxbock	https://github.com/clojure/clojure/blob/clojure-1.7.0/src/clj/clojure/core.clj#L5529
12:43	luxbock	this is what `ns` does for you :)
12:43	xtreak	Yes. Its been confusing. I thought that :require is used to access the parts like a hashmap. But that doesn't make sense as its followed by a vector. Thanks for clearing that its a macro.
12:45	xtreak	I read up source for require as it does some apply operation along with filtering the keywords used in vector. Thanks for the reference :)
12:46	xtreak	Also a question about the error messages in clojure really scare me away as I am a newbie. Is there a way to make runtime checks and throw some exceptions? Any project under development on that?
12:48	luxbock	xtreak: do you know about the pre and post -conditions you can add to functions?
12:48	luxbock	http://blog.fogus.me/2009/12/21/clojures-pre-and-post/
12:48	xtreak	Like take the second argument of map to see if its a function with (type f) and then throw up an error if not.
12:48	luxbock	then there's Prismatic's Schema which is should fit into what you were asking quite well: https://github.com/Prismatic/schema
12:49	xtreak	Ofcourse keywords can be used in maps too just wondering if its possible..
12:49	luxbock	if you use Emacs/CIDER, it sanitizes the stacktraces quite nicely
12:50	luxbock	other editors might do the same but I haven't used them
12:50	xtreak	Pre and post? I came across constraint programming in D lang . not sure if its the correct term. It has precondition and post condition blocks. Is it similar?
12:51	luxbock	xtreak: check out the blog post I linked
12:52	justin_smith	gfredericks: that stream of events in a file thing? if you are allowed to format the edn via transit, it's called kafka, and I've found it pretty awesome
12:52	justin_smith	gfredericks: side effects of that stream of events in a file, is it works as a logged communication channel
12:52	xtreak	I use emacs too ;) I will try out cider. I mostly use lein repl . sure will give it a try. Will check out the blog post. Thanks a lot :)
12:54	luxbock	cider has this nice popup that pretty prints and allows you to filter the stacktraces which I find really helpful
12:54	luxbock	sometimes you want more and sometimes less details
12:55	gfredericks	justin_smith: the use case is super casual though, where you don't want to run a separate process and you want to store the data in git
12:55	xtreak	Read the post. Quite similar to D lang. Cool to learn that :)
13:00	xtreak	Does clojure lazy sequences create intermediate collections. The reason to create transducers where Rich Hickey says in strongloop video IIRC that they avoid intermediate collections. So when I say (map inc (filter odd? (range 10))). Does 1 from range collection pass through filter and to map in same call or filter creates an intermediate collection and feeds to map? If so how is filter lazy?
13:01	justin_smith	xtreak: yes, that map / filter / range creates three lazy seqs, and you use one of them
13:02	justin_smith	it's lazy because it creates its own collection, which doesn't need to realize as many inputs as its source does
13:03	justin_smith	errr s/inputs/elements on the end there
13:04	xtreak	Sorry. I couldn't fully grok that.
13:04	justin_smith	filter walks along the collection that range created, making its own collection
13:05	justin_smith	it will create results only if its own collection is consumed
13:06	xtreak	When I say (range 10) it returns me a promise like thing to generate it when needed. Filter walks through but doesn't generate until consumed? Little confusing that it walks over the range collection but doesn't generate.
13:09	justin_smith	xtreak: it doesn't walk through the range until it needs to produce results
13:09	justin_smith	but it might walk multiple elements of the range to produce one output
13:10	justin_smith	it's a promise like thing, just like range is
13:10	xtreak	So transducers remove the intermediate collection by filter and make it as a single pipeline of different operations than making intermediate collections for each map/filter. Am i correct?
13:10	justin_smith	right, it composes operations without creating new collections in between
13:11	justin_smith	also this means you can transduce on channels too (which are not even collections)
13:11	justin_smith	and one could define ways to transduce on other non-collection sources of input as well
13:11	roelof	why do I see this error message : Mismatched argument count to recur, expected: 1 args, got: 2 on this code : http://lpaste.net/142293
13:12	xtreak	Is the multiple elements mean 32 elements at a time? Sorry to be confusing. Read somewhere that clojure does that.
13:12	justin_smith	roelof: you start the loop with one value, and then try to recur with two
13:13	justin_smith	roelof: maybe you meant (loop [counter 2 n n] ...)
13:13	justin_smith	and you can ditch the let
13:14	justin_smith	roelof: loop is like let, where you declare a binding symbol, and an initial value, so you need two elements in the vector for each binding
13:15	xtreak	justin_smith any place to study more about clojure lazy sequnces?
13:17	xtreak	They look interesting. Am on sicp now.. Will be interesting to compare clojure implementation, streams in sicp and lazy sequences implementation in other languages.
13:17	justin_smith	xtreak: have you looked at the sequence docs on clojure.org? http://clojure.org/sequences
13:21	roelof	justin_smith: thanks, now trying to find out why I see a null pointer exception here : http://lpaste.net/142297
13:21	xtreak	They look a little hazy to me. From wat i understand they are an interface that are implemented by different data structures. Whats an ISeq?
13:21	justin_smith	ISeq is the interface
13:22	xtreak	Maybe am trying to grasp too much being a clojure beginner still ;)
13:22	justin_smith	one implementation of ISeq is lazy-seq, if you use that function, the seq you are creating is lazy
13:23	xtreak	Is sequence a data structure or an implementation of ISeq interface. Sry little confused.
13:24	justin_smith	roelof: after the first recur, answer is not a thing you can use get to look something up in, it will be nil, because you are calling (assoc number number)
13:24	xtreak	Its a logical list says the link
13:25	justin_smith	xtreak: a sequence is some data that implements the ISeq interface
13:25	justin_smith	and the interface ensures that any implementation of ISeq can be used as if it were a linked list (regardless of implementation)
13:25	roelof	pff, what I try to do is summing the right numbers ( n -1) + ( n - 2) and adding it up to answer which will [ 0 1]
13:25	roelof	so again back to the manual
13:26	justin_smith	roelof: right, but in assoc, you only provide two args, and both are numbers
13:26	roelof	justin_smith: oke, so I forget to mention answer :(
13:26	justin_smith	roelof: wait, no, do you even provide a second arg to assoc? don't you just want conj?
13:27	justin_smith	roelof: if what you want is to add to the vector, you don't want to use assoc there, you want to use conj
13:27	justin_smith	and you need to provide answer as the first arg to conj
13:27	roelof	oke, then im confusing those two
13:27	justin_smith	roelof: after the first recur, should answer be [0 1 1] or should it be [1 1] ?
13:28	roelof	justin_smith: it schould be [ 0 1 1 ]
13:28	roelof	and after that [ 0 1 1 2]
13:29	justin_smith	OK, so your last arg to recur should be (conj answer (+ (get answer (- counter 2)) (get answer (- counter 1))))
13:29	justin_smith	you also had the args to get backward
13:29	justin_smith	,(get 1 [0 1])
13:29	clojurebot	nil
13:29	justin_smith	which causes nil
13:29	justin_smith	,(get [0 1] 1)
13:29	clojurebot	1
13:30	justin_smith	that's the version you want
13:30	xtreak	So all data structures that implement ISeq allow themselves to be accessible like a linked list? When I say (seq x) it returns a sequence a linked list representation of the given structure to be precise.
13:31	xtreak	,(seq (into [] (range 10)))
13:31	clojurebot	(0 1 2 3 4 ...)
13:31	justin_smith	roelof: your code will be much easier if the (recur) were refactored to be a let block like (if (= counter n) answer (let [counter (inc counter) n n a (get answer (- counter 2)) ...] (recur ...)))
13:31	xtreak	,(seq (into {} (range 10)))
13:31	clojurebot	#error {\n :cause "Don't know how to create ISeq from: java.lang.Long"\n :via\n [{:type java.lang.IllegalArgumentException\n :message "Don't know how to create ISeq from: java.lang.Long"\n :at [clojure.lang.RT seqFrom "RT.java" 535]}]\n :trace\n [[clojure.lang.RT seqFrom "RT.java" 535]\n [clojure.lang.RT seq "RT.java" 516]\n [clojure.lang.ATransientMap conj "ATransientMap.java" 42]\n [cloju...
13:32	roelof	justin_smith: thanks, my first try to make fib numbers works :)
13:32	justin_smith	xtreak: yes
13:32	xtreak	:):)
13:32	justin_smith	xtreak: the into {} fails because {} expects each element to be a two element vector
13:32	justin_smith	,(seq [1 2 3])
13:33	clojurebot	(1 2 3)
13:33	roelof	justin_smith: oke, so the calculation in the let block and the recur only with the variables you mean
13:33	justin_smith	,(type (seq [1 2 3]))
13:33	clojurebot	clojure.lang.PersistentVector$ChunkedSeq
13:33	justin_smith	roelof: right, instead of having so much logic on one line
13:33	justin_smith	xtreak: if you are ready for more complex details, there's the fact that vectors create a chunked seq
13:34	xtreak	Things make much better sense now. What will be the structure of a lazy sequence?
13:34	justin_smith	xtreak: the only thing that makes lazy sequences, is the function lazy-seq
13:34	justin_smith	check out the doc and examples for that function
13:34	roelof	can I then do more then 1 thing after the false, Or schould I make it works with both in a ( ) ?
13:34	justin_smith	roelof: that's what the let does
13:34	roelof	oke, learned another thing :)
13:35	xtreak	,(type (seq #{1 2 3}))
13:35	clojurebot	clojure.lang.APersistentMap$KeySeq
13:35	justin_smith	,(if false :ORLY (let [a 0 b 1] (+ a b)) ; roelof
13:35	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading>
13:35	justin_smith	err
13:35	justin_smith	,(if false :ORLY (let [a 0 b 1] (+ a b))) ; roelof
13:35	clojurebot	1
13:36	justin_smith	xtreak: also I hope you found this link on the sequence page http://clojure.org/lazy
13:36	xtreak	Is it really a linked list? sets return a different name :(
13:36	justin_smith	xtreak: it can act like a linked list
13:36	justin_smith	the point is that vectors and sets and etc. each return a totally different type, adapted to their source data
13:37	justin_smith	but they all use the same interface, the interface our sequence functions all use, so you can ignore the concrete type most of the time
13:37	justin_smith	because it's a sequence, and that's all that matters usually
13:39	xtreak	So it doesn't matter to the consumer of the sequence too as they only traverse and perform the actions returning a sequence. Right?
13:39	justin_smith	right
13:39	justin_smith	they are effectively using a linked list - even though none of these are a canonical linked-list type
13:40	roelof	justin_smith: it this what you mean ; http://lpaste.net/142298 . It gives a error message on let but it produces the right output
13:41	justin_smith	roelof: the recur should be outside the binding vector
13:42	roelof	I saw it later, Did change that
13:42	justin_smith	also, I think you want a + there, I was thinking you would do more like (let [counter (inc counter) n n a (get answer (- counter 2)) b (get answer (- counter 1))] (recur counter n (+ a b)))
13:43	justin_smith	roelof: also, notice that we can now tell n never changes, so it doesn't need to be a loop arg, and you could take it out of both loop and recur
13:43	xtreak	I looked into the lazy sequence link. Its a little heavy for me. I will go chunk by chunk. Please add other links too that will help me when I get stuck. Thanks a lot for your walkthrough bearing the newbie. Learnt a lot of things justin_smith . Is there any log of clojure channel available ? For my reference.
13:44	justin_smith	oh yeah, lazybot makes one when it is around, as does clojurebot - one moment
13:44	justin_smith	xtreak: http://clojure-log.n01se.net/
13:45	Draco_	I have a hashmap such as {"x" {"user" "stuff"} "user" "z" "y" [{"user" "K"} {"abc" "def"}]}, how do I extract all values of "user" to get a vector such as ["stuff", "z", "K"] ? I've looked at tree-seq, postwalk, but am really stuck.
13:46	xtreak	Sweet :) accidentally closed my irc client and lost all the msgs. Thanks a lot :)
13:47	roelof	justin_smith: when I do this : http://lpaste.net/142299 I see the null exception error again
13:49	justin_smith	,(keep #(get % "user") (tree-seq coll? seq {"x" {"user" "stuff"} "user" "z" "y" [{"user" "K"} {"abc" "def"}]})); Draco_
13:49	clojurebot	("z" "stuff" "K")
13:49	luxbock	roelof: you're trying to use `get` on a number, i.e. the sum of a and b
13:50	roelof	luxbock: so I have to change the arguments
13:50	justin_smith	roelof: yeah, remember it can't just be (+ a b) it has to be (conj answer (+ a b)) - that was my error
13:50	Draco_	sweet justin_smith! That really works. I can see how keep is useful in there.
13:50	luxbock	roelof: also binding something to itself like you do with `n` in the let doesn't really serve any purpose
13:50	justin_smith	luxbock: yeah, I mentioned that n wasn't really needed as a loop arg either
13:53	roelof	oke, changed the code to this : http://lpaste.net/142300 but still the same error, I could be easier if I could see what the values of a b and answer were
13:57	luxbock	roelof: it would help if you also showed how you are calling the function as it's impossible for us to know what `answer` is here
13:57	justin_smith	luxbock: it's [0 1]
13:57	oddcully	you could print them? wrap your block in a do, println first and keep the old code last in the do
13:57	oddcully	or use a debugger
13:58	roelof	luxbock: I call it this way (fib2 [0 1] 5)
13:58	roelof	oddcully: does Lighttable has a debugger then ?
13:59	justin_smith	roelof: it's an off by one because you need to inc counter after calculating a and b
14:00	justin_smith	roelof: https://www.refheap.com/110257
14:01	roelof	justin_smith: that was it. it's not working fine with this code : http://lpaste.net/142301
14:02	justin_smith	not working fine?
14:03	roelof	its working fine. One thing I have to change I think and that is making it work only with n.
14:03	justin_smith	roelof: oh, you can do that with multiple arities
14:03	justin_smith	which is a cool feature, see if you can figure it out
14:04	roelof	I did it this way : (loop [counter 2 n n answer [0 1]]
14:04	justin_smith	oh that's legit too
14:04	roelof	and change fib2 to this (defn fib2 [n]
14:05	justin_smith	also you can take n out of the loop bindings (as it doesn't change)
14:05	roelof	next task. Look if I can make it work with map . I think its better then loop recur
14:05	bendavisnc	can anyone tell me how to disable auto indent in intellij with clojure?
14:05	bendavisnc	maybe i'm being dumb but i can't find it any where and it's driving me bananas
14:06	justin_smith	roelof: map would only make sense if you were mapping over some collection though... I don't think that makes sense here
14:06	justin_smith	roelof: but you could totally do it with iterate / drop-while
14:07	roelof	oke, in programming clojure is stated you almost never need loop reccur , Most things can be done with just the core things
14:07	xtreak	Fib code with iterate is very elegant
14:08	oddcully	bendavisnc: ctlr-alt-a, enter indent and hope for the best?
14:08	oddcully	roelof: dunno about lighttable. i don't use it
14:09	xtreak	https://en.m.wikibooks.org/wiki/Clojure_Programming/Examples/Lazy_Fibonacci
14:10	bendavisnc	oddcully, ugh my alt is tied to my desktop, ubuntu, and still, that's no solution
14:11	oddcully	mine too, but i swapped it with super_l to i still have the old alt
14:11	rhg135	roelof: usually reduce can replace loop
14:12	justin_smith	rhg135: not for a generative thing like fib though
14:12	rhg135	Usually :-P
14:14	roelof	oke, thanks, a lot of things to try tomorrow
14:23	luxbock	,(reduce #(conj % (apply + (subvec % (- (count %) 2) (count %)))) [1 1] (range 10))
14:23	clojurebot	#error {\n :cause "Wrong number of args (2) passed to: sandbox/eval26/fn--27"\n :via\n [{:type clojure.lang.ArityException\n :message "Wrong number of args (2) passed to: sandbox/eval26/fn--27"\n :at [clojure.lang.AFn throwArity "AFn.java" 429]}]\n :trace\n [[clojure.lang.AFn throwArity "AFn.java" 429]\n [clojure.lang.AFn invoke "AFn.java" 36]\n [clojure.lang.LongRange reduce "LongRange.java...
14:24	luxbock	,(reduce (fn [x _] (conj x (apply + (subvec % (- (count x) 2) (count x)))) [1 1] (range 10)))
14:24	clojurebot	#error {\n :cause "Unable to resolve symbol: % in this context"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Unable to resolve symbol: % in this context, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyze "Compiler.java" 6704]}\n {:type java.lang.RuntimeException\n :message "Unable to resolve symbol: % in this context"\n ...
14:24	luxbock	bleh
14:24	luxbock	wouldn't that count as using reduce to replace loop?
14:29	devangshah	can i destructure as well as pass exact params (i.e. without destructuring) to the functions?
14:30	roelof	justin_smith: I like the iterate solution here : https://en.m.wikibooks.org/wiki/Clojure_Programming/Examples/Lazy_Fibonacci, Tommorow I want to look if I can make it work with a end argument instead of the whole map
14:46	zimablue	what's the recommended way to sandbox code? like allow a user to create a function with specified inputs and outputs and no side effects? I've seen clojail but it looks out of development, it basically gives you a whitelist capability?
14:47	gfredericks	devangshah: I'm not sure what your question means, you might try giving an example
14:48	justin_smith	devangshah: maybe two arities, one that provides every input as a separate arg, called by another arity that destructures a single input?
15:05	triss	so how would one find out what platform they're running on in Clojure?
15:05	triss	i.e. OS X/Windows/Linux
15:07	justin_smith	triss: (System/getProperty "os.name")
15:07	justin_smith	,(System/getProperty "os.name")
15:07	triss	thanks justin_smith
15:07	clojurebot	#error {\n :cause "denied"\n :via\n [{:type java.lang.SecurityException\n :message "denied"\n :at [clojurebot.sandbox$enable_security_manager$fn__835 invoke "sandbox.clj" 69]}]\n :trace\n [[clojurebot.sandbox$enable_security_manager$fn__835 invoke "sandbox.clj" 69]\n [clojurebot.sandbox.proxy$java.lang.SecurityManager$Door$f500ea40 checkPropertyAccess nil -1]\n [java.lang.System getProperty ...
15:07	justin_smith	:P
15:33	rhg135	what is the algorithmic complexity of clojure.core/sort ?
15:34	rhg135	O(n)?
15:35	justin_smith	rhg135: it uses java.util.Arrays/sort
15:35	justin_smith	rhg135: nlog(n) http://www.programcreek.com/2013/11/arrays-sort-comparator/
15:37	justin_smith	Arrays/sort is quicksort for primitives, mergesort for Object
15:39	rhg135	I'm dealing with objects
15:40	rhg135	Is it okay to use a vector then sort it?
15:41	rhg135	I want a structure similar to a sorted set but with duplicates and I don't require lookup
15:43	justin_smith	you could just conj then sort for each addition, that's fast for merge-sort
15:44	rhg135	I didn't know if it'd perform well. Thanks
15:52	rhg135	unfortunately, sort returns a seq
15:52	rhg135	not a vector
15:53	rhg135	I can deal with this I think, but it is an issue
16:00	skeuomorf	Is there a builtin function to test if something is an atom or not?
16:00	skeuomorf	or will I have to use `instance?`?
16:02	justin_smith	skeuomorf: I think instance? would be the thing, unless you'd prefer to test if it is a thing you can deref, or swap!, which would use satisfies?
16:03	skeuomorf	justin_smith: I see
16:15	arrdem	ping
16:21	gfredericks	justin_smith: crap I think I made webscale https://github.com/gfredericks/webscale
16:23	arrdem	gfredericks: it's been done before https://github.com/clojure-grimoire/simpledb
16:24	gfredericks	arrdem: where were you three hours ago when I was asking about this
16:24	arrdem	gfredericks: afk same as I've been for about two months now
16:24	arrdem	ish
16:24	gfredericks	arrdem: wait this isn't persistent?
16:24	arrdem	what isn't persistent
16:24	gfredericks	simpledb
16:25	gfredericks	to disk
16:25	gfredericks	I mean
16:25	arrdem	it does persist... at a 2 minute clock tick
16:25	gfredericks	oh okay good I'm still original
16:26	arrdem	so simpledb uses one file for the whole damn thing...
16:26	arrdem	what's yours do?
16:26	arrdem	note that simpledb is circa 2011 from ibdknox
16:26	arrdem	I just cleaned it up a bit
16:26	gfredericks	arrdem: webscale is about storing events on disk, not the current state
16:26	gfredericks	so it just appends events as they happen
16:27	gfredericks	and the in-memory state is based on a reduce function over the events
16:27	arrdem	gfredericks: that's kinda nice
16:27	gfredericks	arrdem: I've got like three different uses for it and was tired of implementing it over and over
16:28	arrdem	gfredericks: gotcha nice
16:28	arrdem	I may have to play with that later
16:29	arrdem	fake partial datomic implementation number....
16:29	gfredericks	:)
16:29	gfredericks	the use case is basically whenever you say "I want my data to be human-readable and probably stored in a git repo"
16:30	gfredericks	the first serious thing I'm going to do with it is to try to replace 4clojure's mongo usage
16:31	arrdem	hum....
16:31	arrdem	I don't think this'd be a net memory savings or I'd try to apply it to Grimoire as well
16:31	arrdem	I'm using simpledb right now to implement some server side analytics
16:31	gfredericks	do you spit the whole state to a new file every 2 min?
16:32	arrdem	same file but yeah
16:32	arrdem	what are append only logs
16:32	arrdem	why do I need those
16:32	gfredericks	is that a question?
16:32	arrdem	I'm being silly
16:32	gfredericks	I suspected
17:31	lxsameer	hey folks, I have a websocket server using Immutant, I want to put it under a heavy load and benchmark it, what solution do you suggest ?
17:31	arrdem	ab for the win
17:32	arrdem	unless you have a number of URLs you want to test in which case you need something else
17:34	sameerynho	arrdem: i don't have any url
17:35	sameerynho	arrdem: and does ab supports websocket load ?
17:44	monsta	Excuseme, when I see a funtion that finish with a asterisk what is the meaning? (example: dosomething*)
17:44	arrdem	monsta: the -* convention is for helper functions or implemenetations which the author didn't have a better name for.
17:45	monsta	Is there any online guide to this nameing convention that I can't refer too?
17:46	arrdem	not really.
17:46	arrdem	gfredericks: is there one I don't know of?
17:47	gfredericks	oh actually
17:48	monsta	Thanks you
17:48	arrdem	I know that the earmuffs convention is mentioned on clojure.org
17:49	gfredericks	this might https://yobriefca.se/blog/2014/05/19/the-weird-and-wonderful-characters-of-clojure/
17:49	arrdem	nah only mentions _ and earmuffs
17:50	arrdem	and -?
17:52	arrdem	$seen yogthos
17:52	arrdem	lazybot wya
17:53	rhg135	he's on an indefinate vacation
17:54	arrdem	lame
17:54	arrdem	clearly I need to start running an instance in addition to Grim...
17:54	rhg135	indeed
17:55	arrdem	well that's one way to get the $grim plugin justin_smith helped me build merged after a year of waiting :P
17:57	kap	hello, new to Clojure, how would I go about working with binary numbers? Do I need to convert them first? 0b1 throws an "Invalid number format" error, but hexes like 0xA works
17:58	arrdem	yeah so 0b1 doesn't wor, but 2r010 will be 2
17:58	kap	oh, 'r' for arbitrary radix?
17:58	gfredericks	,24r24 ;; e.g.
17:58	clojurebot	52
17:58	arrdem	I think it only goes up to 36r....
17:58	gfredericks	,36r1
17:58	clojurebot	1
17:59	gfredericks	,37r1
17:59	clojurebot	#<NumberFormatException java.lang.NumberFormatException: Radix out of range>
17:59	kap	excellent, thanks :)
17:59	gfredericks	,(Long/parseLong "101010" 2)
17:59	clojurebot	42
17:59	gfredericks	,(.toString 42 2)
17:59	clojurebot	#error {\n :cause "No matching method found: toString for class java.lang.Long"\n :via\n [{:type java.lang.IllegalArgumentException\n :message "No matching method found: toString for class java.lang.Long"\n :at [clojure.lang.Reflector invokeMatchingMethod "Reflector.java" 53]}]\n :trace\n [[clojure.lang.Reflector invokeMatchingMethod "Reflector.java" 53]\n [clojure.lang.Reflector invokeInstan...
17:59	gfredericks	,(Long/toString 42 2)
17:59	clojurebot	"101010"
18:00	kap	is the recommended form to use 'r' for portability across clojures?
18:00	gfredericks	rather than what?
18:01	kap	parsing with java
18:02	gfredericks	oh well the use cases are different
18:02	gfredericks	I guess you could use read-string to do runtime stuff more portably
18:14	qmm	what's the reasoning in avoiding static types?
23:12	cfleming	,(into {} (partition 2 1 [["(" ")"] ["{" "}"] ["[" "]"] ["#{" "}"] ["(" ")"]]))
23:12	clojurebot	{"(" ")", "{" "}", "[" "]", "#{" "}"}
23:13	cfleming	Say whut
23:13	cfleming	Here (Clojure 1.7.0) I get "ClassCastException clojure.lang.PersistentVector cannot be cast to java.util.Map$Entry"
23:14	justin_smith	cfleming: there's an error message bug
23:14	justin_smith	cfleming: it will complain about the first thing in the collection, instead of the type of the collection itself
23:15	cfleming	Ok, now I'm confused, actually
23:15	justin_smith	cfleming: one moment, I will find the case that causes the error message bug
23:16	cfleming	My first example should not work, because sure enough partition returns a seq of seqs, not vectors
23:16	cfleming	But I have no idea what clojurebot is on about there, how did it get that map from that input?
23:16	justin_smith	,(into {} '(([a b] c))) ; the error message bug
23:16	clojurebot	#error {\n :cause "clojure.lang.Symbol cannot be cast to java.util.Map$Entry"\n :via\n [{:type java.lang.ClassCastException\n :message "clojure.lang.Symbol cannot be cast to java.util.Map$Entry"\n :at [clojure.lang.ATransientMap conj "ATransientMap.java" 44]}]\n :trace\n [[clojure.lang.ATransientMap conj "ATransientMap.java" 44]\n [clojure.lang.ATransientMap conj "ATransientMap.java" 17]\n [...
23:16	justin_smith	oh it's fixed!
23:17	justin_smith	(locally it complains about persistentvector)
23:17	justin_smith	,clojure-version
23:17	clojurebot	{:major 1, :minor 8, :incremental 0, :qualifier "alpha3"}
23:17	justin_smith	COOL
23:17	justin_smith	,(into {} '((a b) (c d)))
23:17	clojurebot	#error {\n :cause "clojure.lang.Symbol cannot be cast to java.util.Map$Entry"\n :via\n [{:type java.lang.ClassCastException\n :message "clojure.lang.Symbol cannot be cast to java.util.Map$Entry"\n :at [clojure.lang.ATransientMap conj "ATransientMap.java" 44]}]\n :trace\n [[clojure.lang.ATransientMap conj "ATransientMap.java" 44]\n [clojure.lang.ATransientMap conj "ATransientMap.java" 17]\n [...
23:17	justin_smith	OK still not quite right
23:18	cfleming	Ok, so this is actually what I want:
23:18	cfleming	,(into {} (map vec (partition 2 1 [["(" ")"] ["{" "}"] ["[" "]"] ["#{" "}"] ["(" ")"]])))
23:18	clojurebot	{["(" ")"] ["{" "}"], ["{" "}"] ["[" "]"], ["[" "]"] ["#{" "}"], ["#{" "}"] ["(" ")"]}
23:18	Ilie	Hello, I've developed a simple file named functions.clj that I'm trying to import in riemann.config.clj and I keep getting #<CompilerException java.lang.RuntimeException: Unable to resolve symbol: get-owner-email in this context, compiling:
23:18	cfleming	No idea how clojurebot got the result above.
23:18	Ilie	I'm trying to use get-owner-email in riemann.config.clj (the file resides in functions.clj), I've tried to add it using (include "functions'clj") and (load-file "functions.clj") but I still have the same issue, can you please advise?
23:19	justin_smith	Ilie: why not require by the full namespace?
23:19	justin_smith	if your PWD is in the same dir, it would be (load-file "functions"), but it's better to use require
23:20	Ilie	I've created the files using leingen, the files are at the same level, I tried (require 'seiso') but it still doesn't work
23:20	justin_smith	Ilie: that's not how clojure single quotes work
23:20	Ilie	#<CompilerException java.io.FileNotFoundException: functions (No such file or directory)
23:20	justin_smith	if the full ns name was (ns seiso ...), it would be (require 'seiso)
23:21	justin_smith	but if the ns has a compound name, you need to provide the rest of the name, regardless of your working directory
23:23	Ilie	http://pastebin.com/1aaG0F86
23:23	Ilie	I don't have a ns in riemann.config.clj
23:25	Ilie	I've tried now with (require 'seiso) but I get the same error
23:27	justin_smith	Ilie: so why do you have this clj file at the top level of your project, outside the src/ tree?
23:27	namra	Ilie: and the function.clj resides in the same directory as riemann.conf.clj?
23:28	Ilie	I'm just starting out with clojure, adding it to src/ will allow me to use (require 'seiso) ?
23:28	Ilie	What I want is to separate the functionality and to use functions in my riemann config
23:29	justin_smith	Ilie: then why not make a clojure project, and require riemann as a library, rather than adding files to random places in riemann?
23:29	namra	Ilie: how do you executed riemann, because by it'll look for the files within the same directory as riemann.config
23:29	Ilie	len run -- riemann.config.clj
23:29	Ilie	lein*
23:30	justin_smith	Ilie: and putting it inside src is more likely to work - source files are looked up on the classpath, and src/ will be on the classpath by default
23:31	Ilie	Thank you for the suggestions guys, really helpful, I'll try that now
23:31	Ilie	I copied the file to src/seiso.clj and I'm using (require 'seiso) but I get the same error
23:32	namra	more likely src/riemann/seiso.clj
23:33	Ilie	Same thing, I guess I'll just have to inline everything in riemann.config.clj
23:33	justin_smith	namra: that would only work if the ns was riemann.seso
23:34	justin_smith	*reimann.seiso
23:34	namra	justin_smith: oh thanks
23:34	justin_smith	namra: the namespace is just a single element top level ns (which is discouraged, but newbies gonna newb)
23:35	namra	but i think he might not need to put it into src, because all extra configuration for riemann is read at runtime (startup)
23:36	namra	thus when doing lein run on passes it the config option and provides the main configuration file. riemann than looks in the same directory as the main config for includes that are specified within it.
23:37	justin_smith	namra: oh, I had no idea
23:37	namra	anything else would mean baking it right into riemann itself
23:37	namra	cause i use it myself, but never from master. only prebuild uberjars
23:43	Ilie	I copied the file in src/riemann and src/ and restarted riemann but I get the same error, not sure what to try next
23:54	Ilie	I moved my folder to src/riemann/<my_folder> and it works now, thank you guys for the help
23:54	justin_smith	glad you sorted it out...
23:56	namra	Ilie: and in the riemann.config.clj there's only an (include "functions.clj")?
23:56	namra	or do you use a proper namespace as justin_smith mentioned previously?
23:57	Ilie	namra, I don't have a namespace in riemann.config.clj (there is no namespace by default)
23:57	Ilie	I tested again but I can't use the function I wrote so I'm just going to inline everything
23:58	namra	i mean in your functions.clj within src/riemann/<my_folder>