#clojure – 2015-10-09

2015-10-09

01:28	elg	I'm getting "my.namespace.MyRecord cannot be cast to java.util.concurrent.Future" but only in tests. It seems, maybe, to be because my record methods are using the @ reader macro for the atom state?
01:34	justin_smith	elg: yes, "cannot be cast to future" is almost always because the wrong thing has @ in front of it
01:34	justin_smith	,@\?
01:34	clojurebot	#error {\n :cause "java.lang.Character cannot be cast to java.util.concurrent.Future"\n :via\n [{:type java.lang.ClassCastException\n :message "java.lang.Character cannot be cast to java.util.concurrent.Future"\n :at [clojure.core$deref_future invokeStatic "core.clj" 2187]}]\n :trace\n [[clojure.core$deref_future invokeStatic "core.clj" 2187]\n [clojure.core$deref invokeStatic "core.clj" 2209...
01:35	elg	hm. well the @ is in the right place - this works as it should when I use the code, it only breaks in this test
01:35	justin_smith	then your test should be providing something that can be dereffed?
01:36	justin_smith	elg: a favorite trick of mine is providing a delay where the code expects a future or atom, because it can be dereffed, but can't do much
01:36	justin_smith	(which reduces confusion)
01:36	justin_smith	this is all in testing contexts, of course
01:39	elg	ah-hah. It's my mock that doesn't have an atom but should
01:39	justin_smith	or a delay!
02:19	skoude	Noob question, clj-http.client get function return ring map.. The problem is that how can I get just for example print what's inside the :body ? I tried like (println (json :body)) and (println (get json :body)) but none of these works..
02:36	justin_smith	skoude: what is "json"
02:37	justin_smith	try (type json)
02:37	justin_smith	if it's a hash-map like you think, check the values of (keys json)
02:40	skoude	justin_smith: it's: clojure.lang.PersistentArrayMap
02:40	justin_smith	OK, so what are the keys?
02:41	skoude	justin_smith: their: (:orig-content-encoding :trace-redirects :request-time :status :headers :body)
02:41	justin_smith	OK, then (:body json), or (json :body) (I prefer the former) will show you exactly what is there
02:42	justin_smith	maybe the body is empty / nil ?
02:42	skoude	justin_smith: no the body is not empty.. I I write the whole Map to file, I see that there is some json data,..
02:43	skoude	maybe I ave some sort ot typo.. I will double checkk
02:43	skoude	btw.. Have been programming java like 15 years.. and started to lear this yesterday.. Seems like very powerfull language.. It just takes time to learn the syntax :)
02:44	justin_smith	the syntax may be unfamiliar, but it is very simple actually - far less complex than most languages
02:45	skoude	yeap, I noticed that.. just need to get used to it..
02:49	skoude	another stupid question.. If I do like: (filecore/write-to-file "jsonoutput.js" json) the whole map is written to file..
02:49	skoude	but if I do like: (filecore/write-to-file "jsonoutput.js" (:body json)) the object name is just wirtten to file.. D
02:50	justin_smith	I don't get that at all.
02:50	justin_smith	perhaps you shadow the object?
02:50	skoude	In the first one the whole data in the map is written to file with all the json and all the keys
02:51	skoude	but in the second one I get: clojure.lang.LazySeq@b823df75
02:51	skoude	that is written to file
02:52	justin_smith	OK, that's because lazy-seqs print oddly, use pr-str
02:52	justin_smith	pr-str is different from the normal toString in that it tries to print the form that can be read again
02:53	justin_smith	,(str (map inc range))
02:53	clojurebot	#error {\n :cause "Don't know how to create ISeq from: clojure.core$range"\n :via\n [{:type java.lang.IllegalArgumentException\n :message "Don't know how to create ISeq from: clojure.core$range"\n :at [clojure.lang.RT seqFrom "RT.java" 535]}]\n :trace\n [[clojure.lang.RT seqFrom "RT.java" 535]\n [clojure.lang.RT seq "RT.java" 516]\n [clojure.core$seq__4116 invokeStatic "core.clj" 137]\n [cl...
02:53	justin_smith	,(str (map inc (range)))
02:53	clojurebot	#error {\n :cause "Java heap space"\n :via\n [{:type java.lang.OutOfMemoryError\n :message "Java heap space"\n :at [clojure.lang.Iterate next "Iterate.java" 54]}]\n :trace\n [[clojure.lang.Iterate next "Iterate.java" 54]\n [clojure.lang.ASeq more "ASeq.java" 131]\n [clojure.lang.RT more "RT.java" 690]\n [clojure.core$rest__4102 invokeStatic "core.clj" 73]\n [clojure.core$map$fn__4541 invok...
02:53	justin_smith	ergh, never mind, I forget how to make that happen now
02:53	justin_smith	,(str (map inc (range 10)))
02:53	clojurebot	"clojure.lang.LazySeq@c5d38b66"
02:53	justin_smith	,(pr-str (map inc (range 10)))
02:53	clojurebot	"(1 2 3 4 5 ...)"
02:54	justin_smith	there we go, see the difference
02:54	skoude	justin_smith: Thanks, I will try that one out :)
02:54	justin_smith	pr-str has other advantages too:
02:54	justin_smith	,((juxt str pr-str) {:a "hello" :b 'hello})
02:54	clojurebot	["{:a \"hello\", :b hello}" "{:a \"hello\", :b hello}"]
02:55	justin_smith	oops
02:55	justin_smith	,(map print ((juxt str pr-str) {:a "hello" :b 'hello}))
02:55	clojurebot	({:a "hello", :b hello}{:a "hello", :b hello}nil nil)
02:55	justin_smith	I swear there's a case where you see a difference
02:55	justin_smith	aha!
02:55	justin_smith	,(map print ((juxt identity pr-str) {:a "hello" :b 'hello}))
02:55	clojurebot	({:a hello, :b hello}{:a "hello", :b hello}nil nil)
02:56	justin_smith	there's the difference
02:57	skoude	justin_smith: brilliant, it worked like a charm :) No I will parse the json..
02:58	skoude	btw. I noticed that println is taking away the " from json, is there a way to preserve those when printing to console?
02:58	justin_smith	skoude: that's what I was trying to show above
02:58	justin_smith	you can use pr-str to surround the value, or you can use prn instead of println
02:58	skoude	justin_smith: aah, okay I see :)
03:07	skoude	Is there a javadoc equivalent for clojure?
03:07	skoude	or any same kind of mechanism that would automatically generate the documentation from code?
03:16	TEttinger	skoude: there's a literate programming doc generator that's somewhat popular
03:16	TEttinger	under Documentation Tools at http://www.clojure-toolbox.com/
03:17	TEttinger	several are listed
03:18	skoude	TEttinger: thanks, I will check that out
03:18	TEttinger	the literate programming one I was thinking of was https://github.com/gdeer81/marginalia
03:18	TEttinger	I think Codox is more commonly used
04:00	skoude	hmm.. I really don't get this,. (def jsonbody (str(:body json)))
04:00	skoude	it says that: java.lang.String cannot be cast to clojure.lang.IFn
04:01	skoude	I try to assing the :body part of the json -map to jsonbody..
04:01	Seylerius	There isn't a clojure equivalent of pelican/octopress, is there?
04:02	mavbozo	Seylerius, cryogen? http://cryogenweb.org/
04:03	Seylerius	mavbozo: That looks suspiciously like just what I asked for. Thank you.
04:04	ianhedoesit	skoude: is that the exact code that gives that exact error?
04:10	kungi	magnars: In your Parens of the Dead videos you narrow the file to only show functions which call the function you are refactoring. How did you do that in emacs?
04:12	magnars	kungi: it's my symbol-focus mode, found here: sed -i "s/return res/module.exit_json(**res)/g" /usr/local/lib/python2.7/dist-packages/ansible/modules/core/packaging/os/yum.py
04:12	magnars	ack
04:12	magnars	here: https://github.com/magnars/.emacs.d/blob/master/site-lisp/symbol-focus.el
04:16	kungi	magnars: When are you going to release the next video? :-) I want to know more about games and zombies :-)
04:16	kungi	magnars: And thank you!
04:16	magnars	:) I got lazy at some point, but planning to get it done this weekend.
04:20	kungi	magnars: Lazy tsts :-)
04:29	Seylerius	Next question: is there an org parser for clojure?
04:30	Seylerius	Hmm... This seems promising.
04:30	Seylerius	https://github.com/gmorpheme/organum
05:34	skoude	ianhedoesit: thanks, I got it working..
05:34	schmir	I've got a byte[] containing an excel sheet that I like to send back via a ring response to the users browser
05:35	schmir	I get a "java.lang.RuntimeException: class [B is not understandable" from httpkit
05:35	schmir	anyone know how to send back the data?
05:38	skoude	if I decode json string withj parse-string: (def json3 ( parse-string jsonbody));
05:38	skoude	the json3 type is string.. Should that be map?
05:38	luma	schmir, create a ByteArrayInputStream from the byte[] and use that as the response body
05:39	luma	(java.io.ByteArrayInputStream. bytes)
05:40	schmir	luma: that works. Many thanks.
09:20	mkr	I want to do a native app project and am considering Reagent. My friend is pushing for pure react-native as we don't have much experience with Reagent.
09:21	mkr	I want to know whether Reagent can be used for both android and ios development
09:21	mkr	I have seen examples on ios
09:21	mkr	but can't find much help on Android
09:21	mkr	someone tried android development?
09:25	mkr	I guess everyone's busy with their own lives.. thanks :)
09:47	snowell	mkr: You might have more luck over in #clojurescript
09:47	justin_smith	also, not leaving after four minutes
09:47	snowell	Yeah, I have part messages off. That also would have helped
10:57	gfredericks	anybody know the explanation for this off the top of their head?
10:57	gfredericks	,(-> [-128] byte-array String. .getBytes seq)
10:57	clojurebot	(-17 -65 -67)
10:57	gfredericks	I'm not saying it should do anything different, just don't know what's at play exactly
10:57	gfredericks	in terms of encodings
11:08	dstockton	,(-> [-128] byte-array (String. "ISO-8859-1") .getBytes seq)
11:08	clojurebot	(-62 -128)
11:08	dstockton	,(-> [-128] byte-array (String. "ISO-8859-1") (.getBytes "ISO-8859-1") seq)
11:08	clojurebot	(-128)
11:08	dstockton	gfredericks: does that help?
11:10	gfredericks	dstockton: well I'm not trying to achieve a different output
11:11	gfredericks	just trying to explain the one I have
11:11	gfredericks	have been reading some docs and I think it might be undefined behavior, as I think [-128] is not a valid UTF-8 bytesequence?
11:12	dstockton	nope and that's probably the default charset of your system
11:13	gfredericks	right, it is according to (System/getProperty "file.encoding")
11:13	gfredericks	so I think that's a good enough explanation: not all byte sequences are valid UTF-8, and GIGO
12:06	{blake}	Given a list of items, this sums the number of truthy values: (reduce (fn[acc i] (if i (inc acc) acc)) 0 a-list)
12:06	{blake}	I feel like there might be a more elegant way to do that.
12:06	justin_smith	{blake}: (count (remove nil? a-list))
12:08	justin_smith	(apply + (map #(get {nil 0} % 1) a-list))
12:08	justin_smith	that last one is silly
12:09	{blake}	Heh...I like that first one! Is there a "remove falsey?" or would I need a function?
12:10	justin_smith	(keep identity ...)
12:10	justin_smith	I thought you were just taking out nil
12:10	{blake}	summing truthys
12:10	justin_smith	,(keep identity [true nil false :a "" ()])
12:10	clojurebot	(true false :a "" ())
12:10	justin_smith	oh, not keep!
12:10	justin_smith	,(filter identity [true nil false :a "" ()])
12:10	clojurebot	(true :a "" ())
12:11	justin_smith	keep is also nil-specific
12:11	{blake}	Int'resting.
12:12	{blake}	There is false? though.
12:12	{blake}	It's a good example of why you should pick one or the other in a given structure.
13:16	nzst	Hi, is http://www.luminusweb.net/ the only game in town for web frameworks?
13:16	justin_smith	~framework
13:16	clojurebot	framework is a library obsessed with its own abstractions
13:16	justin_smith	nzst: I was hoping for a more helpful factoid from clojurebot, but anyway, in clojure for better or worse, frameworks are not very popular
13:17	justin_smith	that said, pretty much everyone doing web dev with clojure is building on ring (including luminus)
13:17	justin_smith	see also liberator, pedastel, immutant
13:18	nzst	thank you :)
13:50	hoppfull	Hello. I hear calling clojure from java or .net, the preffered way is to use the method where pass a string with the name of the clojure script rather than compiling clojure with (:gen-class). This was a little hard for me to swallow at first but I figure I my instincts might be wrong.
13:50	justin_smith	the string is the argument used to look up a defined var, right?
13:51	hoppfull	Isn't it a little unsafe to call clojure functions with strings? And perhaps not very efficient. Or is my assumption that we need to call clojure from java or c# wrong?
13:51	hoppfull	justin_smith: I think so.
13:51	justin_smith	hoppfull: specifically which method are you supplying a string to?
13:51	hoppfull	justin_smith: give me a sec and I'll get it
13:54	hoppfull	Let's see: in the clr we do IFn myfunc = clojure.clr.api.Clojure.var("myclojurefile", "myfunc")
13:54	justin_smith	right, that's a var lookup
13:54	hoppfull	And then I think we call that function with myfunc.invoke("5"); for example
13:54	justin_smith	hoppfull: that's weird
13:55	justin_smith	unless the function expects a string?
13:55	hoppfull	justin_smith: I originally recoiled at this when I heard this was common practice.
13:55	justin_smith	because clojure functions don't take strings and eval them
13:55	justin_smith	it's not just a bad idea, it isn't even how clojure works
13:55	justin_smith	clojure uses the native data types of its host
13:56	justin_smith	we can explicitly parse strings, but most of our functions are not doing that
13:56	justin_smith	hoppfull: the string arg to var isn't dangerous, it's a lookup in a hash-map, if the wrong string is compiled
13:56	hoppfull	justin_smith: maybe I've got something wrong. Because I insisted on compiling clojure with (:gen-class) and in the REPL (compile 'myclojurefile)
13:56	justin_smith	you don't need to call compile
13:56	justin_smith	hmm...
13:56	hoppfull	But it was so messy that I was sure I was doing it the wrong way.
13:57	justin_smith	so, the Clojure.var call looks up a var in a namespace - it will fail if the namespace is not already loaded
13:57	hoppfull	I've played a lot with clojure for the jvm a while back. And I really liked Clojure. Now I am studying .Net in school and I want to play with Clojure again. Except I am going to stick to .Net.
13:58	justin_smith	usually the first thing you would do is use var to look up require and symbol, and use those to construct and invoke the require call that compiles and loads your code
13:58	justin_smith	var gets string args and looks them up, but otherwise you should be able to use the functions that var returns with the actual data type that function uses
13:58	hoppfull	justin_smith: But this is safe?
13:58	justin_smith	in fact you should be required to do so
13:59	justin_smith	hoppfull: no safer or less safe than using another compiler
13:59	justin_smith	require / compile will both invoke the compiler
14:00	justin_smith	clojure on the jvm or clr does not have a runtime without a built in compiler
14:00	hoppfull	justin_smith: Thanks for the help. I am going to play around a little with this and see if I can get over my anxiety. ; )
14:01	hoppfull	Wait, what do you mean by "built in compiler"?
14:01	justin_smith	hoppfull: clojure supports aot compilation, but the compiler will still be loaded at runtime
14:01	justin_smith	hoppfull: clojure is a compiler
14:01	hoppfull	Right, I've heard this. Doesn't that make it a little slow?
14:01	justin_smith	it's not an interpreter running a script, it's a compiler generating byte-code that can be run by clojure itself or host code
14:02	hoppfull	justin_smith: And doesn't that provide us with the same issues as python? If we don't compile it, how can we protect our source code?
14:02	justin_smith	it's slow in the sense that if you compile at runtime, you have to wait for the compilation - but that shouldn't be your bottleneck
14:02	justin_smith	hoppfull: python compiles?
14:03	hoppfull	justin_smith: No. Not unless you use cython. Which is a problem if you want to distribute your application.
14:03	justin_smith	hoppfull: most clojure folks don't protect their source code, but then again most of us are not shipping client desktop apps
14:03	hoppfull	justin_smith: How could you ever distribute an application in clojure?
14:03	justin_smith	hoppfull: but you can aot compile, and you can ship bytecode without source, it's just not done very often
14:03	justin_smith	hoppfull: I wouldn't
14:03	justin_smith	or at least, I have not yet
14:03	justin_smith	I deploy to servers I control
14:04	justin_smith	and clients connect to that server
14:04	hoppfull	Interesting.
14:04	justin_smith	hoppfull: clojure isn't used much for app dev, but most code being shipped out there is not app code
14:04	justin_smith	most code as in most code in all languages, not just clojure
14:06	hoppfull	I am a little speechless. I didn't know that one wouldn't care about this.
14:06	justin_smith	hoppfull: it hasn't come up because in all my experience coding I have never shipped an "app", only server side or browser based code
14:07	justin_smith	if I were shipping an app that had to be closed source, I would aot-compile and not ship the source
14:08	hoppfull	justin_smith: Alright. Still, aot is a little messy. And it seems unnecessarily slow to me.
14:09	justin_smith	hoppfull: that slowness happens regardless - either at packaging time, or else the same work is done when the app starts up
14:09	justin_smith	there's no free lunch, the stuff is compiled eventually no matter what
14:09	hoppfull	justin_smith: But it's only at startup? I haven't made any large programs with clojure yet.
14:09	justin_smith	Aot is only messy if you have side effects in the top level of your code. You shouldn't be doing that anyway.
14:10	justin_smith	hoppfull: sure, the time is either at build time or start up, but most apps start up multiple times for one build, so build time is the better time to do that job
14:11	hoppfull	justin_smith: This has been interesting. Thanks for your insights!
14:12	justin_smith	np
14:12	justin_smith	in my experience all the changes I need to make for aot to work are fixes of what I would consider bugs in the code (the code was taking some action at compile time that it should not be)
14:13	justin_smith	eg. (def conn (connect db-spec)) - that connects to the db at compile time, which is obviously a bad thing to be doing...
14:34	sobel	justin_smith: heh, i had a similar exp fixinga lot of bugs just to make a nest of spring dependencies work (i was adding spring to a prj that was otherwise pure adhoc spaghetti-OO
14:34	sobel	i didn't realize they were all bugs due to order of creation issues
14:35	sobel	it was my 'object' lesson on not getting fancy with creation patterns
15:07	justin_smith	hehe, you said "object"
15:09	taylan	justin_smith: compiling code actually executes the top-level?
15:10	justin_smith	taylan: yes, which is why you should not have top level side effects
15:10	taylan	weird, would have expected the top-level to be executed at load time
15:10	justin_smith	taylan: clojure's compiler only has one "mode", there is no separate "no side effects" mode available
15:11	justin_smith	in order to compile (def x (foo)), clojure executes foo
15:11	taylan	well, a compiler should not be running any of the compiled code at all (not counting partial-evaluation optimizations), should it?..
15:11	justin_smith	taylan: that's not true of clojure's compiler at all
15:11	taylan	anyway, guess I'll need to get used to that. it's different from how I'm used to things from e.g. Elisp and Scheme
15:11	justin_smith	clojure's compiler doesn't do any optimization either
15:12	justin_smith	taylan: it's a little weird, but it's actually very simple and consistent - only one set of rules to remember :)
15:12	taylan	in a way it also seems simpler though; in the past I found myself confusing library-compile-time from library-load-time in Scheme
15:12	taylan	heh, exactly
15:12	justin_smith	it's just that we are used to other compilers having two behaviors (the compile and load behaviors) and clojure only has the one
15:13	taylan	I didn't know of compilers having a load behavior at all to be honest
15:13	Bronsa	taylan: clojure evaluation strategy during compilation is the same as it would be if you were runnig each form at the repl
15:13	justin_smith	taylan: this is the root of why eg. stuartsierra/component is so popular
15:13	taylan	Bronsa: and then it serializes the resulting process state?
15:13	Bronsa	taylan: I think CL works this way too
15:13	justin_smith	taylan: it offers the sort of deferred behaviors you might want, with very sane defaults and a lot of control
15:14	Bronsa	taylan: no, a top-level is executed both at compile time and at load-time
15:14	taylan	oh...
15:14	Bronsa	taylan: note that doing actual AOT compilation in clojure is not that common
15:15	taylan	I see
16:01	sveri	Hi, how can I define a prismatic schema for "def"?
16:16	sdegutis	How do you prefer to write CSS when you're doing a Reagent project? Do you use Garden?
16:18	justin_smith	sdegutis: best practice is to make someone else do all the CSS by pretending you don't understand it at all
16:19	sdegutis	In my case it isn't pretending, my CSS skills are not the best. ;P
16:19	sdegutis	But I'm the only guy, so I have to do it. I was hoping the scene had improved ever since those older days where everything was new?
16:20	sdegutis	I see Mesh now too..
16:25	sdegutis	https://github.com/facjure/mesh
16:26	justin_smith	sdegutis: mesh looks interesting
16:26	sdegutis	I'm not sure I'd use it though because I've heard you should always roll your own responsive stuff.
16:29	justin_smith	sdegutis: is that the "build your own light saber" of the frontend world?
16:29	sdegutis	Oh nice. Sick reference bro. Everyone knows your references are out of control.
16:30	justin_smith	sdegutis: I have some rare pepes too
16:35	sdegutis	Also Gardener https://github.com/facjure/gardener
16:36	noncom\|2	so, what's mesh
16:36	sdegutis	responsive grid for clojure
16:36	noncom\|2	responsive to what?
16:36	sdegutis	web scale
16:36	justin_smith	noncom\|2: if you don't know what "responsive" is, just be happy, and you don't want any more information
16:36	sobel	(view scale)
16:37	sobel	(inc justin_smith)
16:37	justin_smith	noncom\|2: any more info will just torture your soul
16:37	sdegutis	(inc sobel)
16:37	sobel	,(inc justin_smith)
16:37	clojurebot	#error {\n :cause "Unable to resolve symbol: justin_smith in this context"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Unable to resolve symbol: justin_smith 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:...
16:37	sobel	oh well
16:37	justin_smith	sobel: the bot that does karma is on vacation
16:37	noncom\|2	heh, when sdegutis said "web scale" i thought of something running multiple nodes, like distributed responsive system
16:38	sdegutis	yes, I was intentionally ever so slightly ambiguous
16:38	sdegutis	just in case.
16:38	justin_smith	noncom\|2: if only, that would actually be interesting
16:38	sobel	port your front end to mongodb
16:38	sdegutis	websql
16:38	sdegutis	you mean websql
16:39	sobel	the original web scale joke i knew was around mongodb
16:39	sdegutis	oh yes very good
16:39	justin_smith	help, my web-server is mutating, and is now covered in web-scales, and its attacking innocent ops people in its web-tentacles and devouring them whole
16:39	sdegutis	my memes are out of date, my apologies
16:39	sobel	hehe
16:40	sdegutis	i only recently learned of kid at computer nodding head and giving thumbs up
16:40	emdashcomma	if you get behind enough on memes you will become up to date again
16:40	emdashcomma	eventually
16:40	justin_smith	sdegutis: new hotness: http://i.imgur.com/55feAT3.gif
16:40	noncom\|2	overflow?
16:41	sdegutis	btw i mean this guy http://www.reactiongifs.us/wp-content/uploads/2014/03/brent_rambo_still_approves.gif
16:42	sdegutis	but younger
16:42	sdegutis	justin_smith: oh wow keeper
16:43	justin_smith	sdegutis: proper usage "i m code monkey af rn <gif>"
16:43	sdegutis	lol
17:09	sdegutis	justin_smith: Do you usually call (d/create-database) at the beginning of every process, even though it usually returns false?
17:09	justin_smith	sdegutis: I haven't done much with datomic - I experimented but the project did not go far
17:09	sdegutis	ok
17:13	sobel	i don't get what datomic offers over relational storage
17:14	sdegutis	sobel: it is relational storage
17:15	sdegutis	sobel: it's a middle-ground between sql and nosql in terms of flexibility
17:15	sobel	is it more than relational storage?
17:15	sdegutis	sobel: it's a layer on top of relational storage
17:15	sdegutis	sobel: an extremely handy convenience layer
17:15	sobel	pgsql alreadp gives some middle ground in that way but i understand i could run datomic on top of pg, among others
17:16	sdegutis	writing datomic queries is really pleasant and easy compared to writing sql queries in my experience
17:16	sobel	i'm already really solid with sql
17:16	sdegutis	sobel: and in datomic, queries run in your app, rather than in the database, and there's no blocking
17:17	sobel	what's the concurrency model?
17:35	nefigcas	Hi!!
17:36	nefigcas	There is anybody here??
17:36	mungojelly	nefigcas: kinda
17:36	nefigcas	:D
17:36	justin_smith	sobel: it keeps a cached db, and until you need a new "state", it simply uses the immutable cached db state
17:38	nefigcas	I'm trying come code but it have an weird behavior, Its using Overtone OSC
17:39	nefigcas	I'm mapping(Using map) some code for handlers (kinda listeners)
17:39	justin_smith	nefigcas: you can go ahead and describe your problem, and if you stay logged in eventually someone is likely to help - if you need to share code or errors, put them on a site like refheap.com and share the link here
17:39	xcv	Have any of you guys been using Pulsar?
17:39	nefigcas	But I'm almost shure the thing is not clojure but my understanding of it
17:40	xcv	Looks like an interesting library.
17:40	nefigcas	OK
17:40	mungojelly	nefigcas: map is lazy so if you need the side effects you might want "run!" justin_smith taught me that recently :)
17:41	nefigcas	That sounds like my problem, checking...
17:41	nefigcas	;)
17:43	nefigcas	dorun
17:43	nefigcas	??
17:43	clojurebot	CLABANGO!
17:43	nefigcas	:D
17:43	justin_smith	nefigcas: dorun can wrap map, but run! replaces map directly
17:43	justin_smith	,(doc run!)
17:44	clojurebot	"([proc coll]); Runs the supplied procedure (via reduce), for purposes of side effects, on successive items in the collection. Returns nil"
17:44	justin_smith	,(run! println (range 10))
17:44	clojurebot	0\n1\n2\n3\n4\n5\n6\n7\n8\n9\n
17:46	nefigcas	CompilerException java.lang.RuntimeException: Unable to resolve symbol: run!
17:46	nefigcas	:(
17:47	justin_smith	nefigcas: need clojure 1.7 for that
17:47	nefigcas	Ok, ok
17:47	justin_smith	forgot to mention. But clojure is really good about backward compat, you really don't have much reason not to upgrade.
17:47	justin_smith	or at least try
17:48	nefigcas	Thanks!!
17:49	nefigcas	I was breaking my head with that ;), the code works in the REPL, the REPL is anti-lazy?
17:50	justin_smith	nefigcas: printing forces laziness - rePl
17:51	rhg135	mapv, but the overhead
17:51	justin_smith	,(do (map println ["hello" "world"]) nil) ; no print, no side effect, thanks to do/nil
17:51	clojurebot	nil
17:51	justin_smith	rhg135: which is why run! is great
17:52	rhg135	yeah, I mean on archaic versions
17:55	rhg135	usere refusing to upgrade has led to far too many sleepless nights
17:55	rhg135	users*
17:59	rhg135	or, (reduce #(do (f %2) %1) nil teh-coll)
17:59	justin_smith	,(source run!)
17:59	clojurebot	Source not found\n
17:59	justin_smith	rhg135: anyway, that's pretty much what run! is
18:00	rhg135	yup
18:00	justin_smith	(reduce #(proc %2) nil coll)
18:02	rhg135	run! always returns nil though
18:02	justin_smith	,(run! inc (range 10))
18:02	clojurebot	nil
18:03	justin_smith	rhg135: oh weird, in my older clojure 1.7, (where the source is as I pasted above), it returns the last item
18:04	rhg135	ah
18:17	gfredericks	isn't there a build tool (lein plugin?) for copying dependencies into your project & renaming its namespaces?
18:17	gfredericks	not very easy to google
18:18	justin_smith	gfredericks: sounds like something you could hack together with slamhound...
18:18	rhg135	Sounds buggy
18:18	gfredericks	I've seen bizarre namespaces from such a tool in my deps before
18:18	gfredericks	so it must exist
18:19	gfredericks	I guess it's not a whole lot harder to fork and manually rename the namespaces myself, since it's a one-off
18:22	justin_smith	gfredericks: anyway, slamhound would probably make it easier to engulf, appropriate, and extend a victim project
18:23	numberten	is there a core function that applies a function to each top level value in a map?
18:24	rhg135	is this not the packet managers job? but lein does package the project.clj
18:24	rhg135	map
18:24	justin_smith	numberten: map
18:24	numberten	map turns each key-value to a pair right?
18:24	numberten	and applies the function to the pair?
18:24	rhg135	yeah
18:24	justin_smith	numberten: entries in maps are pairs
18:25	justin_smith	it doesn't "turn them into" anything
18:25	numberten	I want something like: (my-map inc {:a 1 :b 2}) => {:a 2 :b 3}
18:25	justin_smith	specifically they are two element vectors
18:25	rhg135	plumbing has map-val
18:26	rhg135	uses reduce
18:26	numberten	yeah just seemed like it would be commonly used, so was curious if there was a core impl
18:26	justin_smith	yeah, there's also reduce-kv - laziness and hash-maps are like toothpaste and orange juice
18:26	numberten	w/o me writing it with a reduce
18:28	rhg135	why does reduce-kv even excist?
18:28	numberten	(defn my-map [f m] (reduce-kv #(assoc %1 %2 (f %3)) {} m))
18:29	numberten	that's actually not bad at all
18:29	rhg135	destructuring
18:29	justin_smith	destructuring?
18:29	clojurebot	destructuring is http://clojure.org/special_forms#binding-forms
18:30	justin_smith	destructuring???
18:30	rhg135	performance perhaps?
18:30	amalloy	reduce-kv exists because you can avoid allocating a bunch of [k v] pairs, compared to (reduce (fn [acc [k v]] ...) ...)
18:30	rhg135	thought so
18:33	rhg135	That sounds like a good optimiztion for t.a
18:39	rhg135	gfredericks: you could open the jar of a dep that does so and check if it is using a plugin
19:21	sdegutis	justin_smith: huh, seems like I don't need component after all, considering all my components except one (web server) dont have start/stop because they're idempotent
19:22	justin_smith	well, that's super nifty
19:22	justin_smith	not even db connection?
19:22	sdegutis	right, datomic is idempotent
19:22	justin_smith	and no bugs from it trying to connect while building your uberjar?
19:22	sdegutis	it doesnt try to connect until you first access the database
19:22	sdegutis	at which point it opens up a long running connection
19:23	justin_smith	sweet
19:23	sdegutis	yeah this rocks
19:23	sdegutis	totally psyched
19:26	sdegutis	bbl
19:45	justin_smith	,(clojure.string/split "Wat" #"[ -_]")
19:45	clojurebot	["" "at"]
19:45	justin_smith	^^^
19:47	justin_smith	,(clojure.string/split "Wat" #"[ \-_]")
19:47	clojurebot	["Wat"]
19:48	emdashcomma	(let [u m8] (what? u))
20:04	puta	In Hiccup how can I add a title option to a generated list of options? This doesn't work: (defn menu [title start end] (do [:option {:value ""} title] (for [i (range start end)] [:option i])))
20:05	puta	More specifically, in function context. It's simple declaratively.
20:12	nogden	If I implement a protocol in (defrecord) should I be able to call other methods of the same protocol from within my implementation?
20:13	rhg135	yesish
20:14	nogden	I keep getting an unresolved symbol error for the protocol function that I want to call.
20:15	rhg135	weird, since it's defined by (defprotocol ...)
20:15	nogden	Yeah, I figured I could just call it and pass on 'this' and I'd be golden.
20:17	nogden	Ah, bingo. You still have to require the individual methods rather than just the protocol.
20:18	nogden	Thanks, talking things through always helps ;-)
20:18	rhg135	oh, I assumed same ns
20:19	nogden	Fair assumption, I wasn't clear.
20:44	WickedShell	I'm experiencing a problem with lein that I can't seem to track down. lein repl and lein run both work but lein uberjar stalls and never seems to finish
20:45	WickedShell	Anyone ever experienced this before?
21:05	mmitchell	Thinking about building a JS client lib for an API using cljs. Then I thought, maybe I could use the same code to build a js, cljs, clj, js AND java client with the same core. Would this be possible?
21:06	mmitchell	I'd imagine clj and java would use the same "http adapter", while the cljs and JS would use a JS version?
21:16	amalloy	WickedShell: you probably have some side effects at the top level of your namespace, like starting up a server, which never completes
21:17	WickedShell	amalloy, is there a technique for chasing those down? There's some go's etc that get spawned off, but that's always been happening, so I'm having trouble finding the change
21:17	amalloy	those shouldn't happen either
21:17	amalloy	nothing should happen that isn't triggered by -main
21:19	WickedShell	Hm... Well that raises the question of how I've been completing uberjar's in the past, but nicely puts to rest my suspicion that I should move where I spin up some of these go's etc
21:21	amalloy	well it's often harmless, but it's never good
21:26	WickedShell	well that's why I had ignored it, but somehow breaking the jar building is awful :)
21:32	rritoch	Does clojurescript have it's own channel?
21:36	sobel	at least one
21:36	WickedShell	Is the ^:const metadata supported/worthwhile (for constants used in math functions)? I have a fairly tight inner loop that is extremely perfromance bound on my lower end target device
21:37	sobel	rritoch: but it's often a good start to try questions here
21:40	rritoch	sobel: Ok, well I'm looking at cljs-bootstrap, but basically I'd like to bootstrap clojure scripts via AJAX. In a tomcat environment updating scripts/resources typically requires restarting the instance (souch as touching web.xml) which is a less than ideal development environment. Using AJAX I could create a web service which delivers the most up to date code.
21:41	rritoch	souch=such
21:41	amalloy	WickedShell: (def ^:const x (+ 1 1)) will evaluate (+ 1 1), getting 2, and then replace x with 2 every time x is used, as if you had typed 2 to begin with
21:42	WickedShell	(def ^:const x 256) (+ x foo) where foo is something passed in at runtime wont see any benefit then? (just to confirm)
21:42	rritoch	I noted that cljs-bootstrap hasn't been updated in 2 months, and doesn't support macros. Is there some other project which is more capable?
21:50	rritoch	If not, is clojurescript modular, such as being able to deliver namespaces as seperate javascripts (main.cljs.js , draganddrop.cljs.js, etc). If that's possible than it seems I could compile server-side in real time to achieve a comparable effect.
21:51	amalloy	no
22:05	heow	any starving students need a place to crash at the philly conj, ping me
22:12	rritoch	Would it be fair to say clojurescript is best suited for single page applications, since it isn't modular?
23:03	WickedShell	Has anyone here experimented with the skummet compilier at all? I tried swapping my project to it, but seem to be encountering compilation problems that I don't know how to solve at all. (they are occuring outside my code, and in a library somewhere) http://pastebin.com/etqa9u93 (this is with lein-skummet targeting the JVM with Java 8)
23:05	amalloy	you don't have a namespace named pushback-stream?
23:05	amalloy	no, i guess not
23:07	WickedShell	No I don't, its somewher in a library or core
23:08	WickedShell	The exact same code was launching with lein repl before swapping to skummet
23:08	Seylerius	Weird. I can't seem to get clj-barcode to load properly in the Gorilla REPL.
23:09	Seylerius	https://github.com/nmquirk/clj-barcode
23:10	Seylerius	https://clojars.org/clj-barcode
23:12	amalloy	skummet certainly doesn't promise to work with all valid clojure code. there is certainly some it can't handle. i don't know if that's the case you're running into
23:13	WickedShell	amalloy, I suspect that's the case, but thought I'd enquire if anyone had encountered it before. I just have one target device that performance is a real problem on. (Not really clojure's fault, its just weak hardware)
23:17	Seylerius	amalloy: D'you have a minute to take a look at https://clojars.org/clj-barcode and see if you can get it to load into a REPL? I can't manage to make it go.
23:18	Seylerius	I don't know why.
23:18	Seylerius	Ah, nevermind.
23:19	Seylerius	Found it.
23:19	Seylerius	Needed clj-barcode.core, rather than clj-barcode.