#clojure – 2015-07-21

2015-07-21

00:02	crocket	I just looked at lazybot code, and it doesn't provide a sandboxed environment for plugins.
00:02	justin_smith	crocket: it has a sandboxed eval
00:03	justin_smith	&(System/exit 0)
00:03	lazybot	java.security.AccessControlException: access denied ("java.lang.RuntimePermission" "exitVM.0")
00:03	crocket	However, developers will only accept plugins in the 'core' if it doesn't go beyond the boundary of a plugin.
00:23	kavkaz	After using the REPL I feel like putting a right bracket after every sentence I type
00:23	kavkaz	whether it be IRC or SMS on my phone
00:27	rhg135	(like this)
00:29	kavkaz	rhg135: yes
00:30	kavkaz	In some example code in a book about clojure, I'm seeing the character & being used like this: &{}
00:30	rhg135	(not (ready-for? world this))
00:30	kavkaz	what does this mean?
00:30	kavkaz	I know #{} is a set literal
00:30	kavkaz	but what does & mean in this context?
00:30	kavkaz	I couldn't find the character on the clojure cheat sheet.
00:31	rhg135	De structuring
00:31	justin_smith	kavkaz: ##((fn [&{a :a}] (inc a)) :a 1)
00:31	lazybot	⇒ 2
00:31	justin_smith	& indicates that all following arguments are collected
00:31	lazybot	java.lang.RuntimeException: Unable to resolve symbol: indicates in this context
00:31	justin_smith	:P
00:32	justin_smith	and &{ ... } means it will be collected into a key/value hash map
00:32	rhg135	lazybot: disappointed
00:32	justin_smith	most people advise against using &{} actually
00:34	crocket	clojure 1.7 has new features like transducers, reader conditionals, warn on boxed math, update, and run!.
00:36	rhg135	I'm excited for 1.8
00:41	kavkaz	justin_smith: Thank you, I'm starting to get it
00:41	kavkaz	I've started clojure and functional programming a couple days ago, so it's taking some careful looking at
00:41	kavkaz	justin_smith: Why do most people advise against it?
00:42	kavkaz	It's just a map right?
00:42	justin_smith	kavkaz: a common thing to do in clojure is write a function that takes the same args, does some work, then calls the original function
00:42	kavkaz	sorry hashmap
00:42	justin_smith	this is harder to do with & {}
00:43	justin_smith	so, unless the usual usage of & (where you can use apply), you are stuck building the call by hand, or writing "mapply" or something
00:43	justin_smith	it's inconvenient
00:44	kavkaz	justin_smith: How would you do the example code you showed me without &{}
00:44	kavkaz	?
00:44	kavkaz	I'm just curious because I'm new to clojure
00:45	justin_smith	,((fn [{a :a}] (inc a)) {:a 41})
00:45	clojurebot	42
00:45	justin_smith	in this case, the args are in an actual explicit hash-map
00:46	justin_smith	which means that you can use the hash-map to modify the args before calling the original (if you were extending it somehow)
00:48	kavkaz	justin_smith: Okay, I see, thank you
00:48	kavkaz	I'll just have to keep coding and reading this book and the documentation lol
00:54	kavkaz	justin_smith: Oh actually, I've been looking at & in the context of the parameter vector
00:54	justin_smith	kavkaz: yes. That's where it is used.
00:55	kavkaz	Oh true
00:57	crocket	http://blog.cognitect.com/blog/2014/8/6/transducers-are-coming
00:57	kavkaz	well in the example it was [a b & { <map> }
00:57	crocket	justin_smith, Can you tell me more about sandboxed eval?
00:58	kavkaz	[a b & { <map> }]
00:58	justin_smith	kavkaz: sure, same as the other examples, except the a b part
00:58	justin_smith	crocket: I'm about to turn in for the night actually
00:59	kavkaz	After reading some documentation i thought the use of the ampersand in this case was [a b & more]
00:59	crocket	clojail
00:59	justin_smith	kavkaz: the a and b are optional
00:59	kavkaz	where more would be Nil if the passed parameters were only a and b
00:59	crocket	It uses clojail.
00:59	kavkaz	but anyways I'll keep looking into it
00:59	kavkaz	thank you justin_smith
00:59	justin_smith	and "more" is handled differently if it's a hash-map
01:03	kavkaz	good night guys
01:04	crocket	clojail is messy.
01:04	crocket	It requires ~/.java.policy
01:07	tolstoy	Is there an implementation of the ~ operator in Clojure somewhere?
01:08	tolstoy	bit-complement?
01:10	TEttinger	tolstoy: the bit-??? fns do pretty much everything bit-related. Do you mean ~ in... which language?
01:10	tolstoy	Python.
01:10	TEttinger	what does it do in Python? I'm not a python guy
01:10	tolstoy	Basically, swap all 1 bits for 0 bits.
01:10	TEttinger	ah
01:10	TEttinger	uh
01:10	TEttinger	hang on
01:11	tolstoy	I'm porting some code, so that's what's catching me up.
01:11	TEttinger	that seems not very handy, unless it takes more than one arg
01:11	tolstoy	If I knew the exact size of the integer, I could just use bit-flip.
01:11	TEttinger	,(bit-and 0 15)
01:11	clojurebot	0
01:11	tolstoy	seed1 = ((~seed1 << 0x15) + 0x11111111) \| (seed1 >> 0x0B)
01:12	TEttinger	does it also swap all 0 bits for 1 bits?
01:12	tolstoy	I think so.
01:12	tolstoy	http://stackoverflow.com/questions/791328/how-does-the-bitwise-complement-operator-work
01:13	tolstoy	Oh. bit-not, maybe?
01:13	TEttinger	bit-not yeah
01:13	TEttinger	,(bit-not 8)
01:13	clojurebot	-9
01:14	tolstoy	Python: ~2 -> -3
01:14	TEttinger	,(bit-not -2r1000)
01:14	clojurebot	7
01:14	tolstoy	Clojure: (bit-not 2) -> -3
01:14	tolstoy	,(bit-not 2)
01:14	clojurebot	-3
01:14	TEttinger	woo
01:14	tolstoy	Good enough to continue the struggle.
01:14	TEttinger	the 2r thing is handy in case you haven't used it
01:15	tolstoy	What is it?
01:15	TEttinger	r for radix, it's base 2 literal
01:15	TEttinger	you can actually use any radix from 2 to 36
01:15	TEttinger	,2r101101
01:15	clojurebot	45
01:15	TEttinger	,36rFUNZILLA
01:15	clojurebot	1242216307918
01:16	tolstoy	So, give me the base 2 number 101101?
01:16	tolstoy	And then the printer prints it in base 10.
01:17	tolstoy	That is very handy.
01:17	tolstoy	,16rFFF0
01:17	clojurebot	65520
01:18	crocket	It feels like a huge mistake to make namespace mutable.
01:20	TEttinger	tolstoy: if you want to print in base (2 to 36), do ##(Long/toString 1242216307918 36)
01:20	lazybot	⇒ "funzilla"
01:20	TEttinger	tolstoy: if you want to print in base 2, do ##(Long/toBinaryString 1242216307918)
01:20	lazybot	⇒ "10010000100111001110111001001110011001110"
01:23	crocket	,(println "say bitch")
01:23	clojurebot	say bitch\n
01:25	crocket	How do I sandbox arbitrary code without ~/.java.policy?
01:27	TEttinger	I think the contents of java.policy can be added programmatically
01:36	crocket	Is into lazy by default?
01:39	crocket	Listen to one of rich hickey's greatest videos. https://www.youtube.com/watch?v=6mTbuzafcII
01:58	bja	into is strict
02:00	bja	err, eager
02:36	namra	someone using metrics-clojure-ring and can tell me what the rates mean for handling-time.METHOD events?
02:36	namra	the rate of requests/s for that method over 1/5/15min?
04:42	crocket	It feels as if eduction is similar to sequence.
05:14	crocket	Man, it is difficult to understand transducers...
05:18	kungi	Deraen: Ping! Could you help me for a second with my compojure.api code. I upgraded to compojure api 0.22.1 and tried the upload. But now I get the following error: No method in multimethod 'restructure-param' for dispatch value: :multipart-params
05:19	kungi	Deraen: For some reason the multimethod definition from compojure.api.meta is not loaded?
05:29	crocket	Does anyone know a decent transducer learning material?
05:52	crocket	Ok, map returns a transducer. A transducer is passed another transducer or a reducing function to create another reducing function.
05:52	crocket	fn in fn in fn
05:55	crocket	This is a brain massage.
06:05	sandbags	Is there anyone who can help me with lein-wsimport (yes may god have mercy on my soul, SOAP) and a problem I am having enabling external scheme (error 'chema_reference: Failed to read schema document 'xjc.xsd', because 'file' access is not allowed due to restriction set by the accessExternalSchema property'). I've tried specifying :jvm-opts ["-Djavax.xml.accessExternalSchema=all"] in my project.clj which is - i think - the right way
06:05	sandbags	to solve this but no dice. Help!
06:06	sandbags	project.clj & full error here https://gist.github.com/mmower/78a1b440ffce7035832b
06:10	sandbags	i wonder if the problem is that wsimport is not being run with the jvm options... i've no idea how that bit works
06:21	sandbags	lein-wsimport is calling WsImport#doMain so, presumably, will inherit JVM opts so this should work
06:30	sandbags	frak... according to (System/getProperty "javax.xml.accessExternalSchema") it is set to "all" ... :-(
06:30	sandbags	sorry for the stream of consciousness... obv nobody here with any insight into wsimport and probably (just as I would have been) little interest :)
06:31	crocket	Can anyone help me understand transducer step arity?
06:31	crocket	When is it called?
06:33	crocket	Ah
06:33	crocket	ok
06:33	crocket	Completion arity in transducer feels like a boiler plate, doesn't it?
06:43	crocket	I think I found a bug in completing.
06:43	crocket	completing doesn't add 0 arity to a reducing function.
06:44	crocket	sdg
06:44	crocket	-
06:50	crocket	Ouch
07:59	diyfupeco	Is there a way to automatically load new code when something changed on disk?
08:00	diyfupeco	(using leiningen)
08:05	crocket	Is it ok to not define a 0 arity in a transducer?
08:06	wasamasa	diyfupeco: environments like figwheel do that kind of thing
08:06	crocket	,(doc completing)
08:06	clojurebot	"([f] [f cf]); Takes a reducing function f of 2 args and returns a fn suitable for transduce by adding an arity-1 signature that calls cf (default - identity) on the result argument."
08:07	justin_smith	oh, that's very nice
08:07	crocket	completing is not going to work because a transducer requires a 0-arity signature.
08:08	crocket	I understand completing as a way to convert a reducing function into a transducer.
08:09	justin_smith	it addresses the common case where you have an accumulator that holds things other than your result, to simplify getting the part of the accumulator you actually want in the end
08:10	crocket	???
08:10	lazybot	crocket: How could that be wrong?
08:11	justin_smith	crocket: often when I use reduce, the accumulator holds other values along with the actual result
08:11	justin_smith	so I end up needing another function which gets the part I actually want out of the accumulator at the end
08:14	crocket	What is the accumulator?
08:14	crocket	You mean the reducing function?
08:14	justin_smith	,(reduce (fn [[runs run] v] (if (= v (peek run)) [runs (conj run v)] [(conj runs run) []])) [[] []] [:a :a :b :b :b :b :c :c :a :d :d])
08:14	clojurebot	[[[] [] [] [] [] ...] []]
08:14	justin_smith	err
08:15	justin_smith	crocket: the first arg to the reducing function is the accumulator
08:15	crocket	ok
08:15	crocket	initial value
08:15	crocket	Anyway, a transducer created by completing won't serve as a general transducer.
08:16	crocket	I am not sure when the 0-arity signature is used in a transducer.
08:16	justin_smith	,(reduce (fn [[runs run] v] (if (= v (peek run)) [runs (conj run v)] [(conj runs run) [v]])) [[] []] [:a :a :b :b :b :b :c :c :a :d :d])
08:16	clojurebot	[[[] [:a :a] [:b :b :b :b] [:c :c] [:a]] [:d :d]]
08:17	justin_smith	that needs a final step, where [:d :d] is conj'd on the end
08:18	crocket	Your example is hard to read.
08:21	crocket	justin_smith, Can you tell me when the 0-arity signature is used in transducers?
08:35	justin_smith	crocket: it is mentioned by the doc string for transduce
08:36	justin_smith	,(transduce identity (completing (fn [[runs run] v] (if (= v (peek run)) [runs (conj run v)] [(conj runs run) [v]]))) [[] []] [:a :a :b :b :b :b :c :c :a :d :d])
08:36	clojurebot	[[[] [:a :a] [:b :b :b :b] [:c :c] [:a]] [:d :d]]
08:38	justin_smith	completing adds a 1-arg arity
08:39	justin_smith	crocket: I don't know where this 0-arg is that you are talking about
08:39	crocket	,(doc transduce)
08:39	clojurebot	"([xform f coll] [xform f init coll]); reduce with a transformation of f (xf). If init is not supplied, (f) will be called to produce it. f should be a reducing step function that accepts both 1 and 2 arguments, if it accepts only 2 you can add the arity-1 with 'completing'. Returns the result of applying (the transformed) xf to init and the first item in coll, then applying xf to that result and ...
08:39	crocket	transduce avoids using 0-arity signature.
08:39	justin_smith	where is the 0 arity signiture you keep mentioning?
08:39	crocket	By calling (f) directly.
08:40	crocket	justin_smith, http://clojure.org/transducers#toc8
08:41	justin_smith	crocket: OK. It's used to create an initial value for the transduce when none is explicitly supplied. Like it says.
08:41	crocket	justin_smith, https://github.com/clojure/clojure/blob/master/src/clj/clojure/core.clj#L7323
08:42	kwladyka	What about sets performance vs vectors?
08:42	kwladyka	add/remove first/last positions
08:42	crocket	justin_smith, https://github.com/clojure/clojure/blob/master/src/clj/clojure/core.clj#L6566
08:42	justin_smith	kwladyka: sets do not have a "first" or "last" position
08:42	justin_smith	kwladyka: they are not ordered
08:43	justin_smith	crocket: like I said, the docs are clear now that you link them, it creates the initial value for transduce
08:43	kwladyka	,(first #{1 2})
08:43	clojurebot	1
08:44	justin_smith	,(first #{1 2 3 4 5 6 7 8 9 10})
08:44	clojurebot	7
08:44	justin_smith	first will return a value, it will not return the first item, because there is no such thing
08:44	kwladyka	so when i will use it with loop and recur and use first and rest it will work or not?
08:44	justin_smith	definitely not, no
08:45	kwladyka	so bad
08:45	justin_smith	I mean maybe by accident, depending on what you are trying to do...
08:45	justin_smith	but you can't count on any particular item being the first without relying on implementation details
08:45	Wild_Cat	kwladyka: if you want to iterate on the entire contents of a set, use map
08:45	justin_smith	kwladyka: actually, first and rest should split one item off...
08:46	kwladyka	but... if first always return the same element (not exactly first) rest should return always the rest?
08:46	justin_smith	yes, that's true
08:46	crocket	The doc forgot to mention that completing also adds 0-arity signature.
08:46	justin_smith	the order is just weird and undefined
08:47	kwladyka	i don't care about order too much, but i guess performance of sets should be as good as vectors?
08:47	justin_smith	they are slower
08:47	crocket	I think completing should be used as (partial completing f) since cf is the reducing function.
08:47	kwladyka	do you know any statistic? I can't find information liek that
08:48	Wild_Cat	kwladyka: sets are O(1) for insertion, but with a higher constant than vectors
08:48	Wild_Cat	kwladyka: if you don't explicitly care about the uniqueness constraint, a set will be slower than a vector
08:49	kwladyka	anyway... i will do algorithm and if it will be to slow i will change data structure
08:49	justin_smith	kwladyka: runnint criterium now, will share the results when done
08:50	crocket	Now, completing doesn't seem to make a valid transducer.
08:50	Wild_Cat	that said, the fact that you struggle with understanding the very basic performance profiles of these data structures tells me that you're not writing something performance-critical enough to care about the difference. Just use whatever is the most logical for your use case and disregard the performance aspect.
08:51	kwladyka	Wild_Cat, but it is always good occasion to learn something more, like a basic performance :)
08:52	justin_smith	vectors are about 10x faster for appending https://www.refheap.com/106778
08:53	kwladyka	i also see very good side of not mutable data, all things should take less memory
08:53	kwladyka	justin_smith, thank you
08:56	justin_smith	it's really sad that I can tell from the noise floor on my monitors when criterium is done running
08:56	justin_smith	haha
08:56	justin_smith	when the CPU is not working as hard the timbre changes
08:58	justin_smith	kwladyka: paste updated, the ratio gets closer with smaller collections (because some of the shared constant time costs become a bigger part of the resulting runtime I guess) https://www.refheap.com/106778
09:37	crocket	justin_smith, I figured out that completing is not meant to produce a transducer.
09:37	crocket	https://groups.google.com/forum/#!topic/clojure/6cnVMUe5ALE
09:39	crocket	This is really ugly.
09:39	diyfupeco	thanks wasamasa
09:41	crocket	Is there a macro for writing a transducer concisely?
09:42	crocket	or a function for doing so?
09:43	snowell	crocket: Leaving out the final argument to a sequence function call (map, filter, etc) returns a transducer
09:43	snowell	You can comp transducers together to create one that does multiple things
09:46	crocket	snowell, Is there a transducer that drops key-val pairs with nil vals in a map?
09:47	snowell	I would think (remove #(nil? (val %))) should work
09:49	snowell	Heh, or even better… (filter val)
09:49	snowell	,(filter val {:a 1 :b 2 :c nil :d 4 :e 5 :f nil})
09:49	clojurebot	([:a 1] [:b 2] [:d 4] [:e 5])
09:50	snowell	If you want it to be a map, which of course you would, you could (comp (filter val) (into {}))
09:54	crocket	snowell, On https://www.refheap.com/106782 , I rewrote assoc-in-cond2 as assoc-in-cond with transduce.
09:57	snowell	And it's not working?
09:57	crocket	It does work.
09:57	crocket	Can you think of a more concise way to write assoc-in-cond?
09:58	crocket	snowell, ^^
09:59	crocket	I think the function in completing could be written more conscisely.
09:59	snowell	I'm a relative newb compared to others here, so no I can't :D
10:00	snowell	I doubt I'd have gotten it THAT concise to begin with!
10:07	crocket	Is there a function that detects non-sequential value and turns it into a sequence?
10:07	crocket	A transducer is even better.
10:07	crocket	Ah
10:08	crocket	map is a transducer.
10:08	crocket	like (seqify 3) == '(3)
10:08	crocket	(seqify '(3)) == '(3)
10:10	crocket	,(seq :3)
10:11	clojurebot	#error {\n :cause "Don't know how to create ISeq from: clojure.lang.Keyword"\n :via\n [{:type java.lang.IllegalArgumentException\n :message "Don't know how to create ISeq from: clojure.lang.Keyword"\n :at [clojure.lang.RT seqFrom "RT.java" 528]}]\n :trace\n [[clojure.lang.RT seqFrom "RT.java" 528]\n [clojure.lang.RT seq "RT.java" 509]\n [clojure.core$seq__4126 invoke "core.clj" 135]\n [sand...
10:14	sveri	Hi, I want to insert something like {%if toread.done = 1 %}checked{% endif %} into a hiccup form, is there a way to do that?
10:16	hyPiRion	sveri: (if (= (:done toread) 1) "checked") ?
10:16	hyPiRion	I have no idea what toread is, might want to use (.done toread) instead
10:17	sveri	hyPiRion: no, I mean the string: "{%if toread.done = 1 %}checked{% endif %}" into a hiccup form which generates <input ... {%if toread.done = 1 %}checked{% endif %} />
10:17	sveri	sorry for being unclear
10:17	justin_smith	sveri: hiccup forms are just clojure data structures, so there's as many ways to generate that as you like
10:18	justin_smith	sveri: so you have a post-processor over your hiccup output?
10:19	sveri	yea, I generate selmer html templates with hiccup
10:21	sveri	justin_smith: one way would be enough for me :D I am using hiccup like this now [:input {:key "val"} "string"] which generates <input "key"="val">string</input> but as "{%if toread.done = 1 %}checked{% endif %}" is no key value pair I am a bit stuck
10:22	justin_smith	sveri: yeah, when I said that I thought you were talking about generating html
10:22	justin_smith	and of course that's not html
10:23	crocket	Is there a way to map over only values in a map?
10:23	sveri	justin_smith: true
10:23	sveri	ok, so I generate selmer templates
10:23	crocket	,(map #(update % 1 name) {:a :b :c :d})
10:23	clojurebot	([:a "b"] [:c "d"])
10:23	justin_smith	sveri: my sad suspicion is you won't be able to do that because hiccup was never intended to be a general purpose renderer that could do non-html output
10:24	sveri	justin_smith: that's my assumption too after reading the docs, just wanted to make sure I am not missing anything
10:24	justin_smith	,(map name (vals {:a :b :c :d :e :f})
10:24	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading>
10:24	hyPiRion	sveri: I've tried to unescape html into hiccup in the past without luck
10:24	justin_smith	,(map name (vals {:a :b :c :d :e :f}))
10:24	clojurebot	("b" "d" "f")
10:24	justin_smith	,(into {} (map #(update % 1 name) {:a :b :c :d :e :f}))
10:25	clojurebot	{:a "b", :c "d", :e "f"}
10:25	crocket	,(into {} (map #(update % 1 name)) {:a :b :c :d})
10:25	clojurebot	{:a "b", :c "d"}
10:26	crocket	I can't find a way to write it more concisely.
10:28	crocket	Is there a way to write https://www.refheap.com/106785 more concisely?
10:30	sveri	thanks everyone
10:39	crocket	,(reduce #(+ %2) nil [1 2 3])
10:39	clojurebot	3
10:39	crocket	How does it return nil?
10:39	crocket	oops
10:42	perplexa	¯\_(ツ)_/¯
10:42	justin_smith	perplexa: I really wish it was possible to name a function that
10:42	perplexa	haha
10:42	perplexa	isn't it?
10:43	oddcully	you cant?
10:43	justin_smith	it has parens in it
10:43	justin_smith	one moment, faking it
10:43	oddcully	there are for sure some utf-8 parens out there in the wild
10:43	perplexa	my repl strips the ツ :(
10:44	justin_smith	the harder part is the \ I think
10:45	justin_smith	I guess you could just fake the \ and the ( ) with unicodes
10:45	blkcat	#clojure, solving the important problems :P
10:45	justin_smith	the result should be (defmacro \_(ツ)_/¯ [& boxy] `(try ~@body (catch Throwable t :WHATEVER)))
10:46	justin_smith	err, body, whatever
10:47	kavkaz	hey justin_smith
10:48	justin_smith	yes?
10:50	kavkaz	just saying hello
10:50	justin_smith	oh, hi
10:53	wasamasa	justin_smith: now we know what's on your mind
11:04	justin_smith	,(defmacro ¯＼_❨ツ❩_／¯ [& bo `(try ~@body (catch Throwable t# :ok)))
11:04	clojurebot	justin_smith: Pardon?
11:04	justin_smith	:P
11:04	justin_smith	the unicode I used messes with my terminals
11:05	Bronsa	(defmacro (╯°□°）╯︵ ┻━┻ [& body] `(throw (Exception.)))
11:06	gfredericks`	,(defmacro (╯°□°）╯︵ ┻━┻ [& body] `(throw (Exception. ~(pr-str &form))))
11:06	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading>
11:06	Bronsa	ah, the open paren :(
11:06	gfredericks`	the sideways one?
11:07	justin_smith	yeah, I used a doppleganger
11:07	Bronsa	,(defmacro ❨╯°□°）╯︵ ┻━┻ [& body] `(throw (Exception. ~(pr-str &form))))
11:07	clojurebot	#error {\n :cause "Don't know how to create ISeq from: clojure.lang.Symbol"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.IllegalArgumentException: Don't know how to create ISeq from: clojure.lang.Symbol, compiling:(NO_SOURCE_FILE:0:0)"\n :at [clojure.lang.Compiler macroexpand1 "Compiler.java" 6644]}\n {:type java.lang.IllegalArgumentException\n :message "Do...
11:07	justin_smith	or are those already doppleganger parens?
11:07	Bronsa	,(defmacro ❨╯°□°）╯︵┻━┻ [& body] `(throw (Exception. ~(pr-str &form))))
11:07	clojurebot	#'sandbox/❨╯°□°）╯︵┻━┻
11:07	Bronsa	there
11:08	gfredericks`	,(❨╯°□°）╯︵┻━┻ whatever I don't even)
11:08	clojurebot	#error {\n :cause "(❨╯°□°）╯︵┻━┻ whatever I don't even)"\n :via\n [{:type java.lang.Exception\n :message "(❨╯°□°）╯︵┻━┻ whatever I don't even)"\n :at [sandbox$eval96 invoke "NO_SOURCE_FILE" -1]}]\n :trace\n [[sandbox$eval96 invoke "NO_SOURCE_FILE" -1]\n [clojure.lang.Compiler eval "Compiler.java" 6792]\n [clojure.lang.Compiler eval "Compiler.java" 6755]\n [clojure.core$eval invoke "core.clj
11:08	gfredericks`	perfect
11:08	Bronsa	heh
11:08	justin_smith	sweet
11:08	gfredericks`	(clojure.string/join " " (map pr-str &form)) might be slightly better
11:23	crocket	Can anyone write https://www.refheap.com/106785 more concisely?
11:24	crocket	Can I write (fn [m [keys val]] (assoc-in m keys val)) more concisely?
11:31	crocket	#(apply assoc-in %1 %2) can be done, but this is confusing.
11:35	gfredericks`	I am using node with cljs and I don't know what I'm doing
11:35	gfredericks`	debugging is hard
11:37	gfredericks`	I don't know how to get a cljs repl
11:40	crocket	gfredericks`, Are you writing a command line app?
11:43	justin_smith	gfredericks`: you can get a cljs repl with the cljs standalone jar
11:45	gfredericks`	justin_smith: does that use rhino?
11:45	gfredericks`	crocket: developing a library
11:45	gfredericks`	it's not a webby library so I want to avoid browsers if I can
11:49	crocket	webby?
11:52	gfredericks`	has nothing to do with doms or ajax
11:55	justin_smith	gfredericks`: hmm, not sure actually
11:56	csd_	Hello-- If I have two successive calls to >! or >!! to the same channel, is order of delivery guaranteed?
11:56	justin_smith	gfredericks`: https://github.com/clojure/clojurescript/wiki/REPL-Options
11:57	justin_smith	csd_: in terms of control flow in your block of code, it will go start to end. I am not sure if there are strong guarantees of channels being ordered?
11:58	gfredericks`	yep looks like `lein test` can't find .cljc files
11:58	gfredericks`	to the githubmobile!
11:59	justin_smith	gfredericks`: yeah, I ran into this a few times (same issue with eastwood)
11:59	csd_	justin_smith: yeah so if one >! is called before another, is it guaranteed to be delivered first too?
11:59	justin_smith	gfredericks`: I linked to the wrong page before, this is the right one https://github.com/clojure/clojurescript/wiki/Running-REPLs
11:59	csd_	curious about both >! and >!!
11:59	gfredericks`	justin_smith: no github issue for lein yet that you know of?
12:00	justin_smith	csd_: it will be delivered first because the next one won't be run until the first one is
12:00	justin_smith	gfredericks`: definitely an issue, I forget the details
12:00	justin_smith	something about bultitude?
12:00	csd_	ok thanks
12:01	justin_smith	gfredericks`: that wiki page shows separate config for node repl, rhino repl, etc.
12:01	Legendary_Linux	Hey so I'm entirely new to clojure and clojurescript, but I want to learn. Anyone know of some good tutorials to help me learn? A syntax guide would be awesome to start.
12:02	justin_smith	syntax? we don't need no stinking syntax!
12:02	justin_smith	Legendary_Linux: clojure.org has great docs for a start
12:02	justin_smith	for the super basic stuff
12:03	Legendary_Linux	I did find this, which was sort of helpful. http://clojurescriptkoans.com/
12:03	justin_smith	Legendary_Linux: for exercises, 4clojure is great too
12:03	justin_smith	http://www.4clojure.com/
12:03	Legendary_Linux	justin_smith: Thanks.
12:04	justin_smith	just be aware the difficulty is not all in numeric order, feel free to start skipping eventually
12:04	justin_smith	it will suggest "try X next" and X isn't always the best next puzzle to try
12:05	gfredericks`	justin_smith: this repl stuff looks promising, thanks
12:05	justin_smith	Legendary_Linux: depending on how much programming experience you have, there is also clojure from the ground up by aphyr, and clojure for the brave and true
12:05	justin_smith	gfredericks`: yeah, thankfully dnolen realized how tangled the world of cljs tooling got and prioritized making some (relatively) simple options available. Which is awesome.
12:05	justin_smith	(inc dnolen)
12:05	lazybot	⇒ 23
12:08	Legendary_Linux	I have history with C, C++, and Java. That was a few years ago, though. More recently I've been doing PHP, JS, and Node.js
12:09	justin_smith	yeah, clojure from the ground up would likely be a bit too introductory then
12:10	justin_smith	though clojure for the brave and true might be OK, if you can handle how "twee" it can be sometimes
12:10	Legendary_Linux	Twee?
12:10	justin_smith	Legendary_Linux: kinda cute, silly
12:11	blkcat	i enjoyed clojure for the brave and true
12:11	Legendary_Linux	How much difference is there between Clojure and ClojureScript?
12:11	blkcat	but you definitely have to be OK with a great deal of levity :p
12:12	justin_smith	Legendary_Linux: they both use host interop a lot. Aside from the host interop they are very similar.
12:12	Legendary_Linux	I can deal with that. Thanks for the suggestions, all.
12:12	justin_smith	the host interop will be very familiar based on your java / javascript experience
12:12	justin_smith	though the syntax is different of course
12:19	dnolen	not sure of ATXers hang out here but https://twitter.com/swannodette/status/623527687932481536
12:29	crocket	Is there a build-in function for (map #(update % 1 fn) {:a :b ...})?
12:29	crocket	It is map-val.
12:35	gfredericks`	there is no built-in map-vals
12:35	gfredericks`	the easiest is (into {} (for [[k v] m] [k (f v)]))
12:36	gfredericks`	prismatic/plumbing has it; I'm sure other util libs do too
12:36	TimMc	crocket: clojure.algo.generic.functor/fmap
12:37	gfredericks`	oh dear
12:37	crocket	TimMc, Is it part of core?
12:37	TimMc	nope
12:37	TimMc	No lie, we have pulled in that entire lib just for fmap on maps. It's kind of silly.
12:37	crocket	I have (into {} (map #(update % 1 name) m))
12:37	TimMc	[org.clojure/algo.generic "0.1.2"]
12:38	gfredericks`	TimMc: that's kind of silly
12:38	TimMc	crocket: (zipmap (keys m) (map f (vals m)))
12:38	TimMc	there are so many ways to write this
12:39	crocket	So many ways to confuse users
12:39	TimMc	fmap is written (into (empty m) (for [[k v] m] [k (f v)]))
12:39	TimMc	but maybe for perf it should use transients?
12:48	justin_smith	TimMc: I thought into used transients
12:48	justin_smith	oh wait no it uses transducers, my bad
12:48	crocket	transducers win over transients
12:49	justin_smith	but trans* beats everything
12:49	crocket	Oh my god, iterate creates a recursive data structure!!!
12:50	justin_smith	um, it can
12:50	justin_smith	it doesn't have to
12:50	justin_smith	,(iterate inc 0)
12:50	clojurebot	(0 1 2 3 4 ...)
12:50	blkcat	they were clearly overwhelmed by this revelation
12:50	justin_smith	nothing recursive about that data structure
13:08	xemdetia	and then they died
13:11	scriptor	wonder what they meant by recursive data structure
13:35	mmeix	short question:
13:35	mmeix	I have in a let:
13:36	mmeix	(let [sw1 (if (< s e) 1 0), sw2 (if (= 1 sw1) 0 1)])
13:36	mmeix	there must be a more elegeant way to say this
13:37	gfredericks`	sw2 (- 1 sw1)
13:38	mmeix	ah, silly me ... thanks!
13:39	mmeix	(inc gfredericks)
13:39	lazybot	⇒ 142
13:44	gfredericks`	mmeix: there's also (bit-xor 1 sw1)
13:44	mmeix	wow
13:44	mmeix	ok ...
13:45	mmeix	would be much faster, I guess ...
13:45	gfredericks`	hypothetically
13:45	justin_smith	,(bit-xor 1 1)
13:45	clojurebot	0
13:45	justin_smith	,(bit-xor 1 0)
13:45	clojurebot	1
13:45	TimMc	blkcat: "My god, it's full of cons cells!"
13:45	mmeix	the wise are thinking alike :-)
13:47	mmeix	aha, this is a function of clojure.lang.Numbers in source, interesting
13:47	scriptor	not sure if bit-xor would be that much faster
13:48	mmeix	(in my case speed doesn't matter much)
13:49	mmeix	(just flipping a flag in a SVG path)
13:49	gfredericks`	yeah do whatever is the clearest to you
14:01	gfredericks`	omg I think I have to implement bit-count for 64-bit integers in cljs
14:01	justin_smith	gfredericks`: how do you even do a 64 bit integer in cljs? where do you get the extra bits to make that work?
14:04	gfredericks`	justin_smith: gclosure has a Long
14:04	TimMc	justin_smith: Store them as properties on the number.
14:04	gfredericks`	lol
14:05	TimMc	(function(x) { x.foo = "bar"; console.log(x.foo); })(3)
14:05	TimMc	^ Prints undefined, but does not error.
14:05	gfredericks`	erroring would be hostile to developers
14:05	gfredericks`	nobody likes to see error messages
14:08	TimMc	I think 3 is getting boxed as a Number, but I don't know why Number silently throws away property writes.
14:10	gfredericks`	what does it mean for a js number to be boxed?
14:11	amalloy	TimMc: (function(x) {console.log(x.foo="bar");})(3) // quick hack TODO figure out why this is needed
14:11	TimMc	amalloy: :-)
14:12	TimMc	gfredericks`: new Number(3) + 5 //= 8
14:12	TimMc	typeof new Number(3) //= "object"
14:13	TimMc	typeof Number(3) //= "number"
14:14	amalloy	TimMc: actuall new Number(3) + 5 == 8 in my browser
14:14	amalloy	but here is a funny thing i just found in the ecmascript spec: Number is the inverse of new Number
14:24	justin_smith	amalloy: did you see my hilarious destructuring pitfall the other day?
14:24	amalloy	uh
14:25	amalloy	oh, the keyword and some sort of not-actually-space space?
14:25	justin_smith	,(let [{:keys {a b c d}} {:a 0 :b 1 :c 2 :d 3}] [a b c d])
14:25	clojurebot	[nil nil nil nil]
14:25	amalloy	hah
14:25	justin_smith	of course the keys arg should have been a vector
14:25	justin_smith	but it just silently gives you nil
14:26	justin_smith	amalloy: led to a hilarious wild goose chase
14:26	amalloy	,(let [{:keys #{a b c d}} {:a 1 :b 2 :c 3 :d 4}] [a b c d])
14:26	clojurebot	[1 2 3 4]
14:26	amalloy	,(let [{:keys #{a b c d e f g h i}} {:a 1 :b 2 :c 3 :d 4}] [a b c d])
14:26	clojurebot	[1 2 3 4]
14:26	amalloy	hmmmph, i was hoping for some sort of rearrangement from the conversion to hashset
14:27	justin_smith	another fun one (which I found much faster) ##(let [{:keys [a b c :a all]} {:a 0 :b 1 :c 2}] all)
14:27	lazybot	⇒ nil
14:27	justin_smith	of course the :as all needs to be moved out of the vector
14:27	justin_smith	err, I didn't even do the :as right this time
14:27	justin_smith	another fun one (which I found much faster) ##(let [{:keys [a b c :as all]} {:a 0 :b 1 :c 2}] all)
14:27	lazybot	⇒ nil
14:28	Bronsa	c.c/destructure is just awful
14:29	Bronsa	unreadable, unmaintainable and accepts lots of bad inputs
14:29	amalloy	Bronsa: has anyone tried to rewrite it? it seems like it shouldn't be that hard to redo from scratch, even if reading the existing one is impossible
14:29	Bronsa	amalloy: have fun trying to get a refactoring commit into clojure
14:30	justin_smith	Bronsa: on top of that, also it can be slow, and it can undermine laziness
14:30	amalloy	oh, sure
14:30	justin_smith	those might be harder to fix
14:30	amalloy	justin_smith: you mean because of the nth calls?
14:30	justin_smith	amalloy: I think so, it's actually something that came to my attention via yourself. I just superstitiously avoid destructuring when I need maximal laziness now :P
14:31	Bronsa	amalloy: I think the big issue with the current version is that it tries too hard to be super generic and reuse one code-path to do all the nested destructuring
14:31	amalloy	oh, i meant the slowness. that's not what causes laziness issues
14:31	Bronsa	justin_smith: it can also mess with locals clearing!
14:31	justin_smith	ahh, I just know that from benchmarking. Probably the extra collection making and such? not sure
14:31	justin_smith	wow
14:31	Bronsa	(because of a bug in locals clearing though)
14:32	TimMc	amalloy: //= was supposed to be a comment followed by an equals sign, like ;;=
14:32	Bronsa	justin_smith: it will sometimes bind unused and unreachable locals which the compiler can't clear. I have a ticket w/ patch in jira but..
14:32	amalloy	justin_smith: well because it calls nth a lot
14:33	amalloy	,(#'clojure.core/destructure '[_ _ _ _ _ _ _ _ _ _ x])
14:33	clojurebot	[_ _ _ _ _ ...]
14:33	amalloy	,(#'clojure.core/destructure '[[_ _ _ _ _ _ _ _ _ _ x] y])
14:33	clojurebot	[vec__128 y _ (clojure.core/nth vec__128 0 nil) _ ...]
14:33	justin_smith	ahh
14:33	amalloy	so if y is a seq it calls nth 0, nth 1, nth 2...
14:33	justin_smith	nice
14:33	amalloy	where instead it could be using nthnext and first
14:35	Bronsa	amalloy: uh, are you saying walking a seq of a vector is faster than accessing each element?
14:36	amalloy	Bronsa: for a vector it's not, and for a seq itis
14:36	TimMc	&(let [{:keys {AAAAA BBBBB}} {(keyword "[AAAAA BBBBB]") [5 6]}] AAAAA) ;; amalloy, another result from justin_smith's discovery
14:36	lazybot	⇒ 5
14:36	kwladyka_	How to transform (1 2 3 4) into (4 1 2 3)?
14:36	kwladyka_	in elegant way
14:36	Bronsa	amalloy: right, I guess vector destructuring is optimized for vector access
14:36	TimMc	kwladyka_: (constantly (list 4 1 2 3))
14:36	amalloy	right, but an awful lot of the time we actually have lists
14:37	hiredman	no, it is sequential destructuring
14:37	Bronsa	ah
14:37	amalloy	and it's not hard to check whether the thing you're destructuring supports nth via whatever interface
14:37	Bronsa	yeah, true that
14:37	kwladyka_	TimMc, ?
14:37	amalloy	or to make nthnext and first be fast on vectors (like subvec)
14:37	TimMc	kwladyka_: (cons (last xs) (butlast xs)) perhaps
14:37	TimMc	kwladyka_: You didn't explain the relationship between the two, so I had to guess.
14:38	TimMc	Maybe you want all inputs to become (4 1 2 3), for example!
14:38	amalloy	TimMc: that was the one i guessed when he asked me
14:38	kwladyka_	TimMc, you have strange intuition :)
14:38	kwladyka_	TimMc, anyway thx for solution
14:38	amalloy	although since i wasn't reading it at the time i mis-guessed the cause
14:38	chouser	(->> xs cycle (drop 3) (take 4))
14:39	TimMc	kwladyka_: Did I guess right, then?
14:39	kwladyka_	TimMc, (cons (last xs) (butlast xs))
14:40	chouser	kwladyka_: depending on the other operations you intend to do, a persistent queue might work well
14:41	kwladyka_	chouser, can you give me an example?
14:43	chouser	a persistent queue is fast for conj'ing on one end and peek/pop'ing from the other, so you could efficiently take an item (4) from one end and put it back on the other end.
14:44	chouser	if you do that a lot, or on a large collection, it might be more efficient than a vector or list which has to be rebuilt every time you do that "rotate" operation you asked about
14:44	chouser	on the other hand, it may then be hard to access the full contents of the collection in the order you want for whatever else you're doing with it.
14:45	kwladyka_	chouser, are you talking about http://clojuredocs.org/clojure.core/persistent! ?
14:45	chouser	nope.
14:46	chouser	,(-> clojure.lang.PersistentQueue/EMPTY (into [1 2 3 4]))
14:46	clojurebot	#object[clojure.lang.PersistentQueue 0x22125a58 "clojure.lang.PersistentQueue@e93c3"]
14:47	kwladyka	oh... thx
14:47	chouser	,(let [q (into clojure.lang.PersistentQueue/EMPTY [1 2 3 4])] (-> q (conj (peek q)) pop seq))
14:47	clojurebot	(2 3 4 1)
14:48	gfredericks`	conj-peek-pop-seq would be a good name for something
14:48	kwladyka	generally i need do from (1 2 3 4 2 3 53 23 932 2) all possible configurations
14:48	chouser	,(let [q (into clojure.lang.PersistentQueue/EMPTY (reverse [1 2 3 4]))] (-> q (conj (peek q)) pop reverse))
14:48	clojurebot	(4 1 2 3)
14:48	kwladyka	*all possible unique configurations
14:49	chouser	so, those 'reverse' operations are relatively expensive, but if you can do the things you need to in-between them, or figure out how to never need them, you'd be winning.
14:50	amalloy	"all possible configurations?"
14:50	amalloy	you are looking for the function named permutations, or what?
14:51	kwladyka	amalloy, i have chess pieces and i have to try them in all possible unique configurations from first to the last one
14:51	amalloy	what is a unique configuration?
14:52	amalloy	this is getting back to TimMc's answer
14:52	kwladyka	so (:king :king :queen) (:king :queen :king) (:queen :king :king:) <- this is easy one.
14:52	gfredericks`	sounds like permutations
14:52	kwladyka	as you can see :king is 2 times there
14:53	kwladyka	but i am not doing (:king :queen :king) twice because it doesn't make sense
14:53	kwladyka	gfredericks`, but there is no function like permutation in Clojure as i seee
14:55	kwladyka	hmm but maybe http://clojure.github.io/math.combinatorics/#clojure.math.combinatorics/permutations
14:56	gfredericks`	,(defn unique-permutations [xs] (let [m (frequencies xs)] ((fn self [m] (if (empty? m) [[]] (mapcat (fn [[x n]] (map #(cons x %) (self (if (= 1 n) (dissoc m x) (update m x dec))))) m))))))
14:56	clojurebot	#'sandbox/unique-permutations
14:56	gfredericks`	,(unique-permutations [:king :king :queen])
14:56	clojurebot	#error {\n :cause "Unable to resolve symbol: unique-permutations in this context"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Unable to resolve symbol: unique-permutations in this context, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyze "Compiler.java" 6543]}\n {:type java.lang.RuntimeException\n :message "Unable to r...
14:56	gfredericks`	what
14:56	gfredericks`	,sandbox/unique-permutations
14:56	clojurebot	#error {\n :cause "No such var: sandbox/unique-permutations"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: No such var: sandbox/unique-permutations, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyze "Compiler.java" 6543]}\n {:type java.lang.RuntimeException\n :message "No such var: sandbox/unique-permutations"\n :at [cl...
14:56	gfredericks`	,(defn unique-permutations [xs] (let [m (frequencies xs)] ((fn self [m] (if (empty? m) [[]] (mapcat (fn [[x n]] (map #(cons x %) (self (if (= 1 n) (dissoc m x) (update m x dec))))) m))))))
14:56	clojurebot	#'sandbox/unique-permutations
14:56	gfredericks`	,(unique-permutations [:king :king :queen])
14:56	clojurebot	#error {\n :cause "Wrong number of args (0) passed to: sandbox/unique-permutations/self--71"\n :via\n [{:type clojure.lang.ArityException\n :message "Wrong number of args (0) passed to: sandbox/unique-permutations/self--71"\n :at [clojure.lang.AFn throwArity "AFn.java" 429]}]\n :trace\n [[clojure.lang.AFn throwArity "AFn.java" 429]\n [clojure.lang.AFn invoke "AFn.java" 28]\n [sandbox$unique_...
14:57	kwladyka	gfredericks`, i guess clojurebot doesn't remember function from query before
14:57	gfredericks`	,(defn unique-permutations [xs] (let [m (frequencies xs)] ((fn self [m] (if (empty? m) [[]] (mapcat (fn [[x n]] (map #(cons x %) (self (if (= 1 n) (dissoc m x) (update m x dec))))) m))) m)))
14:57	clojurebot	#'sandbox/unique-permutations
14:57	gfredericks`	,(unique-permutations [:king :king :queen])
14:57	clojurebot	((:king :king :queen) (:king :queen :king) (:queen :king :king))
14:57	gfredericks`	hey yay
14:57	gfredericks`	only two tries
14:57	gfredericks`	,(unique-permutations [:king :rook :queen])
14:57	clojurebot	((:king :rook :queen) (:king :queen :rook) (:rook :king :queen) (:rook :queen :king) (:queen :king :rook) ...)
14:57	gfredericks`	,(unique-permutations [:king :king])
14:57	clojurebot	((:king :king))
14:58	amalloy	that's a cute way to handle duplicates, gfredericks`
14:58	gfredericks`	amalloy: thanks!
14:58	kwladyka	gfredericks`, respect
14:58	gfredericks`	I like to think of frequencies as returning a multiset
15:07	TimMc	clojurebot: I like to think \|of\| frequencies
15:07	clojurebot	'Sea, mhuise.
15:09	snowell	Just when I think I understand these bots...
15:11	rhg135	Heh
15:14	kwladyka	damn... i killed intellij using permutation in REPL
15:18	gfredericks`	hey snapchat I just successfully ported the immutable RNG to cljs
15:18	gfredericks`	it gives identical results
15:19	dnolen	gfredericks`: cool did you end up using goog.math.Long for this?
15:19	gfredericks`	dnolen: oh absolutely
15:19	dnolen	gfredericks`: cool!
15:19	gfredericks`	dnolen: I had to write bit-count myself but everything else was there
15:19	dnolen	gfredericks`: excellent
15:19	gfredericks`	dnolen: next comes the part where I find out it's unsalvageably slow
15:20	dnolen	gfredericks`: haha, I suspect it will be OK, I think test.check would dominate not goog.math.Long ops
15:20	gfredericks`	I hope so
15:20	dnolen	gfredericks`: last I checked it as something like 4X perf hit over regular arithmetic
15:21	dnolen	and the biggest time sink in test.check is GC
15:21	kwladyka	oh god... it produce so many results from so small collection
15:21	gfredericks`	dnolen: makes me want to rewrite the generators with transducers
15:21	gfredericks`	kwladyka: the maybe good news is that it's lazy
15:21	dnolen	gfredericks`: def
15:22	justin_smith	,(defn get-name [] (->> 'clojure.core ns-publics keys shuffle (take 3) (clojure.string/join \-) symbol))
15:22	clojurebot	#'sandbox/get-name
15:22	justin_smith	,(repeatedly get-name) ; gfredericks`
15:22	clojurebot	(spit-nnext-command-line-args char?-subs-dissoc! comment-completing-read-string apply-keys-int print-method-case-drop ...)
15:23	gfredericks`	(inc justin_smith)
15:23	lazybot	⇒ 279
15:23	kwladyka	gfredericks`, yes but i am scare of time needed to run whole algorithm from start to the end
15:24	gfredericks`	kwladyka: yeah combinatorial stuff can be tricky that way
15:24	kwladyka	which each permutation i need check all possible configuration on chess
15:24	kwladyka	*with
15:25	gfredericks`	kwladyka: is it a permutation of 8 pieces?
15:25	kwladyka	hmm but as i see 99% of time it was time to show me text on screen not counting
15:25	gfredericks`	,(defn unique-permutations [xs] (let [m (frequencies xs)] ((fn self [m] (if (empty? m) [[]] (mapcat (fn [[x n]] (map #(cons x %) (self (if (= 1 n) (dissoc m x) (update m x dec))))) m))) m)))
15:25	clojurebot	#'sandbox/unique-permutations
15:25	gfredericks`	,(count (unique-permutations '(R N B K Q B N R)))
15:25	clojurebot	5040
15:25	kwladyka	gfredericks`, no... as many as user want on board size as user want
15:25	justin_smith	,defn get-name [] (->> 'clojure.core ns-publics keys (mapcat (fn [s] (clojure.string/split (name s) #"-"))) shuffle (take 3) (clojure.string/join \-) symbol))
15:25	clojurebot	#error {\n :cause "Can't take value of a macro: #'clojure.core/defn"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Can't take value of a macro: #'clojure.core/defn, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyze "Compiler.java" 6543]}\n {:type java.lang.RuntimeException\n :message "Can't take value of a macro: #'clojur...
15:25	justin_smith	,(defn get-name [] (->> 'clojure.core ns-publics keys (mapcat (fn [s] (clojure.string/split (name s) #"-"))) shuffle (take 3) (clojure.string/join \-) symbol))
15:25	clojurebot	#'sandbox/get-name
15:26	justin_smith	,(repeatedly get-name)
15:26	clojurebot	(update-count-seq 1-min-ctor condp-with-print byte-chars-history boolean-vector-vary ...)
15:26	kwladyka	anyway... i have to finish algorithm and we will see how long it will take
15:26	kwladyka	there is no other way :)
15:34	TimMc	(inc justin_smith)
15:34	lazybot	⇒ 280
15:35	TimMc	,(meta #'completing)
15:35	clojurebot	{:arglists ([f] [f cf]), :doc "Takes a reducing function f of 2 args and returns a fn suitable for\n transduce by adding an arity-1 signature that calls cf (default -\n identity) on the result argument.", :added "1.7", :line 6560, :column 1, ...}
15:35	gfredericks`	heck yeah it generates identical doubles as well
15:35	TimMc	that's great!
16:39	riogr	In my program, I have the state in a variable I call `current-buffer`. It has an atom, that is swap!-ed and reset!-ed at certain times. Should you in clojure earmuff such variables? They never change (always point to the atom) but the value from deref-ing the atom _is_ changing. To earmuff or not to earmuff?
16:42	justin_smith	riogr: in clojure earmuffs are for dynamic bindings, not atoms
16:43	riogr	I see. Thank you justin_smith for clearing it up! Back to the hacking...
16:43	justin_smith	riogr: there's even a message about it
16:43	justin_smith	,(def foo (atom nil))
16:43	clojurebot	#error {\n :cause "denied"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.SecurityException: denied, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyzeSeq "Compiler.java" 6740]}\n {:type java.lang.SecurityException\n :message "denied"\n :at [clojurebot.sandbox$enable_security_manager$fn__835 invoke "sandbox.clj" 69]}]\n :trace\n [[clojureb...
16:43	riogr	justin_smith: saw that, but didn't really understand..
16:43	justin_smith	err... that's not the usual message
16:44	justin_smith	riogr: OK. there's a good section on dynamic bindings on clojure.org where vars are documented
17:12	DocSolver	Hi all! I'm trying to teach myself clojure with a book and the REPL and I have two questions:
17:13	DocSolver	My first question: when I start a REPL outside a project I get an outdated Clojure version (1.6.0), even though I made a project.clj in the ~/.lein folder with a dependency on 1.7.0. Am I doing something wrong?
17:14	DocSolver	('m on MacOSX)
17:17	justin_smith	DocSolver: lein doesn't use a project.clj from .lein
17:18	justin_smith	DocSolver: you'll need to wait for a newer lein version before non-project repls use the brand new clojure version (it's only been official for a few weeks at most)
17:18	DocSolver	ok, then I must have misread that somewhere.
17:18	DocSolver	thank you for the clarification!
17:18	justin_smith	np
17:19	justin_smith	DocSolver: in practice it's not so hard to just use projects
17:19	justin_smith	since they are so easy to generate
17:19	DocSolver	k, will do
17:20	DocSolver	also, another thing I was wondering is about the syntax: it is mostly quite clear but I am confused by the cases where a keyword has a specific meaning. For example the :keys speical keyword to destructure a hashmap. Why is this a keyword and not a function?
17:20	justin_smith	I have a "just experimenting" project that pulls in clojure 1.7 plus some of my favorite libs like core.async (which I use often, but not ubiquitously to put in my profiles.clj)
17:20	justin_smith	DocSolver: because that keyword is handled specially by that reader - you can think of it like command line args on a *nix system
17:21	justin_smith	DocSolver: the function is clojure.core/destructure
17:21	justin_smith	and it uses things like :keys and :as to guide its execution
17:21	DocSolver	does that mean that these keywords are reserved? Or only in that specific context?
17:21	justin_smith	there's a macro that grabs that binding vector, then feeds it to destructure, then uses the result
17:22	justin_smith	no, they are not reserved, they just have a special meaning in that context, similar to command line switches
17:22	justin_smith	DocSolver: really it's not much different than how a vector is used by defn / fn
17:23	justin_smith	it's not that the vector is special, it's that fn / defn treat a vector in that position in a special manner
17:23	DocSolver	but it does matter that the keyword is named :keys right?
17:23	justin_smith	DocSolver: sure, other keywords mean other things in that context
17:23	justin_smith	DocSolver: like :strs
17:24	DocSolver	I haven't stumbled upon that one in the book I'm reading yet... but I will keep it in mind
17:24	DocSolver	Thanks for the clarifications Justin, really appreciate!
17:24	justin_smith	DocSolver: yeah, :strs is practically secret, it gets used so rarely :)
17:24	justin_smith	np
17:25	justin_smith	,(let [{:strs [a]} {"a" 41}] (inc a))
17:25	clojurebot	42
17:27	DocSolver	justin_smith: so what is the added value of using :strs ?
17:27	justin_smith	DocSolver: same as for keys, avoids repetition when destructuring
17:28	justin_smith	DocSolver: often a hash-map coming from a database or an http API will come back with strings as keys rather than keywords
17:29	justin_smith	what most people do is do a tree-walk converting the strings to keywords (or at least walking and converting the top level, or converting while parsing with a json parser). Really you can just use the strings.
17:30	DocSolver	You managed to confuse me a bit with the :str :-) I don't really see the difference with :keys. I assume it's not an alias?
17:30	justin_smith	DocSolver: :keys works with keywords, :strs works with strings
17:31	justin_smith	these are different datatypes, they are not equivalent when used as hash-map keys
17:31	justin_smith	,(get {"a" 0} :a)
17:31	clojurebot	nil
17:31	justin_smith	,(get {"a" 0} "a")
17:31	clojurebot	0
17:31	DocSolver	The example about :keys in the book I'm reading is:
17:31	DocSolver	,(let [{:keys [flower1 flower2]} {:flower1 "red" :flower2 "blue"}] (str "The flowers are " flower1 " and " flower2))
17:31	clojurebot	"The flowers are red and blue"
17:32	DocSolver	It obviously doesnt work if I replace :keys with :strs but your example seems really similar
17:32	justin_smith	DocSolver: I bet you could translate that to use :strs, by changing the keys in the map
17:32	DocSolver	Is it because you're extracting only one key?
17:32	justin_smith	DocSolver: it is because :a is not equal to "a"
17:32	justin_smith	they are different data types
17:32	DocSolver	Aaaah, now I see: your key is a string
17:32	justin_smith	:a is not a special syntax for map keys, it is a type of data
17:33	DocSolver	Okay, it's good that you point that out because I practically only see :keys being used as... erm... keys in objects
17:33	justin_smith	DocSolver: objects != hash-maps
17:33	justin_smith	hash-maps are one class of objects
17:34	justin_smith	but we have Objects via the jvm too, entirely different beast usually...
17:34	justin_smith	DocSolver: but stick to hash-maps now, and use them as you would usually use objects, and you can sort out the rest when you are more experienced
17:35	DocSolver	Okay; I did mean hash maps but I'm still too much in Javascript lingo...
17:36	DocSolver	Actually the :keywords system in Clojure kind of reminds me of symbols in the new Ecmascript 6 which are provided as a means to avoid collisions that might occur with string keys. Or is this not a good comparison?
17:36	justin_smith	DocSolver: heh, if you ever use cljs, you can use js Objects and cljs hash-maps (which are a kind of js object...)
17:36	justin_smith	DocSolver: well, keywords can be namespaced, and we use the namespacing to avoid collisions
17:37	DocSolver	but what is the added value of keywords, as opposed to using strings instead?
17:37	justin_smith	but we also use keywords in literal source code because it helps differentiate a string used as a data type representing human readable text, as opposed to keys in a map or other usage of tokens
17:37	justin_smith	also keywords can be called like functions, they look up a value in a hash-map
17:38	justin_smith	,(:foo {:foo 0})
17:38	clojurebot	0
17:39	DocSolver	okay, that's clear.
17:40	DocSolver	So it's actually other languages which use strings for both purposes and clojure separates these uses by creating a separate data type...
17:41	justin_smith	DocSolver: right. I saw a comical version of this the other day from a haskell user on twitter: "should the type be string? I dunno, would the complete works of shakespeare translated to mandarin be a valid value?"
17:42	DocSolver	:two_households_both_alike_in_dignity_In_fair_Verona_... no that doesn't feel right :-)
17:42	justin_smith	haha
17:43	DocSolver	actually, the fact that a leyword can't contain spaces is a clear indicator of what you wrotr
17:43	justin_smith	DocSolver: right. Well a literal can't. As you learn more clojure you find out all kinds of evil terrible bad things you shouldn't do that are actually quite easy.
17:44	DocSolver	I don't wanna know :-)
17:45	DocSolver	Alright Justin, you helped me a lot. Now I'm returning to the book and the REPL :-) This was a nice first experience with the Clojure community!
17:45	justin_smith	,(keyword "OK I won't tell you how.")
17:45	clojurebot	:OK I won't tell you how.
17:46	justin_smith	DocSolver: awesome, thanks
17:47	DocSolver	,(keyword "Two households, both alike in dignity, In fair Verona, where we lay our scene, From ancient grudge break to new mutiny, Where civil blood makes civil hands unclean. From forth the fatal loins of these two foes A pair of star-cross'd lovers take their life; Whose misadventured piteous overthrows Do with their death bury their parents' strife. The fearful passage of their death-mark'd love, And the continuance of their p
17:47	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading string>
17:47	DocSolver	even romeo and julia doesnt fit...
17:48	justin_smith	it's an irc limitation, lol
18:05	sdegutis	Help.
18:06	sdegutis	This works from `lein run`, but not from inside a jar: (->> (resource "public/assets") (file) (file-seq))
18:06	sdegutis	It complains with an illegal argument exception saying "not a file".
18:07	sdegutis	So in Clojure, whether in a .jar or not, how do you get a list of files in a directory within your ./resources/ dir?
18:10	justin_smith	sdegutis: things inside jars are not files
18:10	justin_smith	sdegutis: if you want to access things inside jars, don't use file, use resource
18:10	justin_smith	sdegutis: jars do not contain directories
18:11	sdegutis	Okay.
18:11	sdegutis	So then, in Clojure, whether in a .jar or not, how do you get a list of "files" in a "directory" within your ./resources/ dir?
18:13	justin_smith	well, "resources" itself won't be in the jar
18:14	Cr8	there's not really a good way to do it it -- (resource) will pull a file out of any jar on the classpath
18:14	justin_smith	best you can do is list things under some relative path on the classpath
18:14	Cr8	so you have to use the ZIP apis to check every jar on the classpath
18:14	justin_smith	answer to that, I am working on
18:14	hiredman	there is a large assumption there
18:14	hiredman	that things can only come out of jars on the classpath
18:15	Cr8	also dirs on classpath
18:15	hiredman	resource, and resources actually load things from classloaders
18:15	hiredman	which can, for example, magic up stuff out of no where, or load things from random urls, etc
18:15	Cr8	yeah, could have a magic classloader that you can't actually ask for a list
18:15	Cr8	like some http server you dont control -- you cant necessarily get a listing
18:17	amalloy	justin_smith, Bronsa: in case anyone is interested i wrote up a version of destructure that isn't just one giant function, and uses first/next on vectors instead of nth: https://www.refheap.com/de3767810a33dd855f0bc803e
18:17	sdegutis	Thanks. I'll do this outside Closure.
18:17	justin_smith	amalloy: cool
18:17	sdegutis	Appreciated much.
18:18	amalloy	doesn't have all the error handling but i think it has all the features
18:44	justin_smith	just found an apt quote from a 20th century music composer: "now that things are simple, there's so much to do"
18:44	justin_smith	(Morton Feldman)
21:47	slaterr	map returns a lazy sequence. what does a lazy sequence mean exactly? is it like iterators in C++? or sequence in python
21:49	amalloy	it is a thing you can get an iterator on. but it stays valid when you do, and future calls cache the already-computed values. it's not like an iterator that gets mutated as you request elements from it and can only use once
21:49	slaterr	yeah I see
21:50	slaterr	what if I only iterate it once? how much memory will it use
21:52	celwell	Hello, does anything like this already exist? (defmacro unless [pred x y] `(if (not (~pred ~x)) ~x ~y))
21:52	celwell	Ex. usage: (unless Double/isNaN (Double. "0.75") 0)
21:52	celwell	Or, is there a better pattern?
21:53	amalloy	celwell: why would that be better than using when-not?
21:53	amalloy	oh, you're not returning nil, but rather y
21:54	celwell	Yeah, it's an if but i don't want to rewrite 'x'
21:55	celwell	My name unless is kind of misnomer
21:56	amalloy	i don't think there's anything very good built-in. with flatland/useful you could write (-> x (fix pred y))
21:56	slaterr	or, to repharse, if I iterate through a lazy sequence with a million elements only once will they all be stored in memory or will it just use memory required to store a single element?
21:56	amalloy	slaterr: i mean the GC is nondeterministic so it could run whenever, but when the GC does run, only one element wll be kept
21:58	celwell	amalloy: huh... seems like it would be a common pattern for data validation w/ defaults
21:58	slaterr	i thought maybe clojure compiler is smart enough to notice that it does not need to cache all those results, since they are not used again
21:59	amalloy	actually maybe cond-> does that now. i don't remember how that works
21:59	amalloy	,(doc cond->)
21:59	clojurebot	"([expr & clauses]); Takes an expression and a set of test/form pairs. Threads expr (via ->) through each form for which the corresponding test expression is true. Note that, unlike cond branching, cond-> threading does not short circuit after the first true test expression."
21:59	amalloy	,(cond-> 2 even? inc)
21:59	clojurebot	3
21:59	amalloy	,(cond-> 2 odd? inc)
21:59	clojurebot	3
22:00	amalloy	right, thought so. it wants a bool, not a predicate, so it doesn't help you avoid repeating x
22:03	celwell	Thanks a cool function though, might be useful for other things. Thanks
22:39	namra	hm is there no way to ask leiningen for verbose output
22:39	namra	cause it's kinda frustrating when compilling something and it just hangs somewhere
22:39	namra	without ever finishing
22:46	justin_smith	namra: that's caused by top level side effects
22:47	justin_smith	namra: all your namespaces get run at the top level when compiling, the only way to make it not hang is to have no side effects at the top level of the file
22:47	justin_smith	anything that "does anything" should be in functions called by your -main
22:48	justin_smith	namra: you can use jstack (it's a command line tool that comes with the jdk) to see where the clojure process is hanging
22:49	namra	justin_smith: thanks
22:50	namra	currently i solved it by removing :aot :all from the uberjar profile
22:50	namra	but like to know why it doesn't work on the new dev machine cause on the old one the compiliation works
22:50	justin_smith	oh, that's interesting
22:51	justin_smith	in my experience a hanging compile is almost always some small thing I didn't notice, like launching a core.async go block in a def
22:52	justin_smith	(which means the core.async threads spin up, which means the compiling vm does not exit)
22:55	namra	justin_smith: thanks that was the issue
22:55	justin_smith	core.async?
22:55	clojurebot	core.async is 100% imperative
22:57	namra	had code that connected to a server outside of main
22:57	justin_smith	ahh
23:27	namra	ah how i'd like to do more with clojure :/
23:28	blkcat	i'm dreadfully tempted to use om for an upcoming work project
23:28	namra	om?
23:29	justin_smith	namra: clojurescript library that uses react.js (but actually performs better thanks to immutable data structures last I heard)
23:29	justin_smith	namra: from the brilliant dnolen
23:29	justin_smith	~om
23:29	clojurebot	Titim gan éirí ort.
23:29	namra	ah thanks
23:30	blkcat	it looks absolutely brilliant
23:30	TEttinger	clojurebot: om is a clojurescript library that uses react.js . Om is so hot right now!
23:30	clojurebot	Ik begrijp
23:31	justin_smith	TEttinger: I improved my clojure.core name generator
23:31	TEttinger	oh?
23:33	justin_smith	TEttinger: digging it up
23:33	justin_smith	,(defn get-name [] (->> 'clojure.core ns-publics keys (mapcat (fn [s] (clojure.string/split (name s) #"-"))) shuffle (take (inc (rand-int 3))) (clojure.string/join \-) symbol))
23:33	clojurebot	#'sandbox/get-name
23:34	justin_smith	(repeatedly get-name)
23:34	justin_smith	,(repeatedly get-name)
23:34	clojurebot	(re send-dorun object-with-drop defmulti-keep-aset >Vec-key-dec' ...)
23:34	justin_smith	,(repeatedly get-name)
23:34	clojurebot	(sig-make class?-run! read->>-memfn var?--inc filter ...)
23:34	justin_smith	oh wait
23:34	amalloy	read->>-memfn
23:34	amalloy	solid name
23:34	amalloy	var?--inc
23:34	justin_smith	,(defn get-name [] (->> 'clojure.core ns-publics keys (mapcat (fn [s] (clojure.string/split (name s) #"-"))) shuffle (take (+ 2 (rand-int 3))) (clojure.string/join \-) symbol))
23:34	clojurebot	#'sandbox/get-name
23:34	justin_smith	,(repeatedly get-name)
23:34	clojurebot	(identity-at-defprotocol biginteger-remove eval-min macroexpand-class-coll-complement map?-unreduced-int ...)
23:35	justin_smith	amalloy: one I just got in my repl here - >Vec-vec->>
23:35	justin_smith	,(repeatedly get-name)
23:35	clojurebot	(pop-ref-next-repeat >=-ctor find-bit-find-method set->-matcher-array proxy-reader ...)
23:36	amalloy	computer-generated babble is always strangely compelling
23:37	justin_smith	for me I think it's cathartic because I have spent so much time cramming things made of those tokens into my brain already
23:38	justin_smith	,(repeatedly get-name)
23:38	clojurebot	(error-transient list-set-unsigned-errors deref-groups not-biginteger subtract-re-int-underive ...)
23:39	amalloy	not-biginteger. a useful function indeed
23:39	justin_smith	indeed, should be a predicate, of course
23:40	justin_smith	,(repeatedly get-name)
23:40	clojurebot	(unchecked-in-set-send type-min-in fn*-filterv string-create->map-not satisfies?-shift-aset-with ...)
23:41	tmtwd	is there something like hiccup for css?
23:42	justin_smith	tmtwd: garden
23:42	tmtwd	justin_smith, is it often used by clojure developers?
23:42	justin_smith	tmtwd: the only reason I haven't used it is designers would rather just use regular css, or maybe sass/less
23:43	amalloy	that's true of hiccup too
23:44	justin_smith	amalloy: yeah, we have an unusual division of labor now, which lets us use reagent stuff which is basically hiccup syntax, but before we had to use a more conventional templating engine