#clojure – 2016-03-13

2016-03-13

01:43	ilevd	Hi, I can't live without Clojure, what can you recommend me?
01:52	burhanloey	Other Lisp?
01:54	burhanloey	Hylang is a lisp too on top of Python, but I haven't try it yet.
01:55	ilevd	Other Lisp?
01:56	ilevd	Try Pixie https://github.com/pixie-lang/pixie
01:56	burhanloey	Other lisp = Common Lisp, Scheme, Racket etc
01:57	ilevd	Racket looks good, but perfomance...
01:57	burhanloey	Yup, I'm aware of Pixie
03:02	ilevd	It's interesting if anybody uses Hylang in production
03:05	TEttinger	ilevd: what are you asking for recommendations on again?
03:05	TEttinger	like library choices?
03:05	TEttinger	or other clojure-like lisp dialects?
03:06	ilevd	I don't know, I like Clojure but there isn't job on it and I don't know what to programm )
03:17	dysfun	ilevd: quite a few of us here have clojure jobs
03:17	dysfun	many of us work for ourselves, of course
03:21	ilevd	Cool!
04:40	henke	im currently using this to server index.html (GET "/" {c :context}
04:40	henke	(redirect (str c "/index.html"))) however this puts /index.html on the
04:40	henke	path and i want a path that is only / when serving the index page?
05:48	Empperi	cfleming: any way to tell Cursive to recheck dependencies from project.clj when it's been modified outside of cursive?
05:48	Empperi	I've been trying out boot as my build tool and have boot auto generate proejct.clj with dependencies for Cursive
05:48	Empperi	this works fine as long as I've generated the project.clj updates before I launch Idea
05:49	Empperi	if I do it afterwards I cannot get Cursive to understand the new dependencies
05:49	Empperi	obviously drives me nuts
05:51	Empperi	if I quit Idea and reopen it then Cursive understands the new dependencies
05:51	TEttinger	Empperi: ooh ooh ooh!
05:52	TEttinger	I got this fixed yesterday, from cfleming
05:52	TEttinger	view -> tool windows -> Leiningen, there's a refresh button in a blue arrow circle icon
05:52	TEttinger	upper left of the tool window
05:53	Empperi	awesome, thanks!
05:54	TEttinger	someone earlier mentioned boot not working as well as could be, but his workaround was the same as what you're doing with the export to lein
05:54	TEttinger	I think the only problem was .boot files not supported
05:58	Empperi	yeah nothing is understood in those files
05:58	Empperi	but I can live with that
05:58	Empperi	as long as my actual code works as expected
05:59	Empperi	supporting boot as a first class citizen in Cursive is going to be really difficult since the power and flexibility of boot makes it really hard to evaluate for Cursive
06:01	dysfun	but what does it really need to integrate?
06:01	dysfun	'boot repl' is a default, for example
06:02	dysfun	cider under the hood just changes which command it runs in a subprocess
06:02	TEttinger	cursive uses cider under the hood? isn't cider an emacs thing?
06:03	dysfun	yes, i'm noting that it was simple for the competition
06:03	TEttinger	ohhhh, I misread
06:03	cfleming	dysfun: Cursive is more complicated than CIDER in this respect.
06:04	cfleming	It needs to know which dependencies to sync, so they can be attached to the project and indexed.
06:04	cfleming	That is very difficult in boot.
06:04	Empperi	yeah
06:04	dysfun	is it? (get-env :dependencies) doesn't work in nrepl?
06:05	Empperi	Cursive does not use REPL for code syntax evaluation
06:05	Empperi	it uses static analysis
06:05	cfleming	That only works if a) you execute your build, and who knows what that will do, and b) you're sure you've executed all code paths in your build.
06:05	cfleming	I have plans for a much better integration, but it will never be perfect.
06:05	Empperi	part a) is especially true with boot :)
06:06	dysfun	yes, but i tend to agree that a build is a useful place to write code
06:06	cfleming	I'm actually becoming a huge Gradle fan.
06:06	dysfun	i think boot is great for the power it gives you, but i think the api is awful
06:06	cfleming	You can write code, but the important bits are still declarative enough that tooling has a chance to work.
06:06	Empperi	gradle has it's own problems too
06:07	cfleming	Sure, it's a build tool - it's a matter of choosing the one you hate the least
06:07	dysfun	i would expect that it's going to work fine 90% of the time+
06:07	dysfun	all of my build.boot start off with (set-env! :dependencies ...)
06:07	dysfun	and i think most other people are the same
06:07	dysfun	no reason static analysis can't pick that sort of thing up
06:07	Empperi	yeah but nothing forces you to do it like that
06:07	cfleming	dysfun: Sure, and that case is relatively easy to solve statically.
06:07	Empperi	those scenarios are easy to support
06:08	cfleming	But I've heard of people keeping their deps in maps and dynamically loading those maps etc
06:08	cfleming	But I'm ok with telling those people that they're off the Cursive beaten path and that bets are off.
06:08	dysfun	yeah, i'd do exactly that in your position :)
06:09	Empperi	I'd be happy if Cursive would support a) set-env! based dependencies b) would recognize defined tasks
06:09	Empperi	plus would understand the code itself meaning it wouldn't try to tell me there is no such thing as set-env! or deftask and so forth
06:09	cfleming	Empperi: Yes, all that is possible and planned.
06:09	Empperi	don't need REPL integration or anything it doesn't already have
06:10	Empperi	since with boot you pretty much want to start nrepl and connect to that
06:10	Empperi	you'll lose debugging which sucks but so does life sometimes
06:10	cfleming	Yeah, debugging might be tricky but remote debugging is always an option.
06:10	Empperi	yeah
06:11	dysfun	i'm facing this dilemma at the minute actually for a documentation tool
06:11	dysfun	a certain amount of static analysis topped up with a certain amount of executing code i think
06:11	dysfun	(i want to produce clojure and clojurescript docs in one document)
06:11	Empperi	but if I need to make a choice between boot support and macro improvements I'll choose the latter :)
06:11	cfleming	Empperi: BTW better macro solutions are coming down the pipe soon too, I know that's been hurting you.
06:12	cfleming	Haha snap
06:12	Empperi	you read my mind lol
06:12	Empperi	ikitommi_ will be happy to hear that too
06:14	cfleming	Yes, no doubt
06:24	dysfun	how have you found building on top of eclipse in practice, then?
06:24	cfleming	dysfun: Me? Cursive is built on top of IntelliJ
06:24	dysfun	oh
06:25	cfleming	CounterClockwise is the Eclipse one.
06:25	dysfun	ah that's right
06:27	cfleming	IntelliJ is actually really nice to build on, but it's enormous and almost totally undocumented.
06:28	cfleming	I ran cloc over it the other day actually, the community edition is 3.9 million LoC
06:28	dysfun	wow
06:28	cfleming	It takes a while to check out.
06:29	dysfun	haha, longer than webkit?
06:29	cfleming	I've never tried, but I'd bet a beer that it does.
06:29	dysfun	webkit is 5gb
06:29	dysfun	(the git repo)
06:29	cfleming	That's quite a lot.
06:30	dysfun	yeah. it's the sort of thing where you start to notice git doesn't tell you how much it intends to download
06:30	cfleming	Not sure how to check that size on the community edition, I can't find a simple way to clean the build artifacts.
06:31	dysfun	hah
06:32	cfleming	(there probably is one, but I only have the code for reference, I don't actually build + run it)
06:32	dysfun	oh, git clean -df then
06:32	cfleming	Of course
06:33	cfleming	du -sh show 4.9 GB
06:33	dysfun	wow, so totally comparable to webkit
06:33	cfleming	Looks like it, yeah.
06:35	cfleming	https://github.com/JetBrains/intellij-community/graphs/contributors
06:37	Empperi	168 678 commits :)
06:37	Empperi	and 32 925 releases
06:37	Empperi	lol
06:38	cfleming	yole tops out at like 100 commits/week
06:38	Empperi	Jetbrains employee?
06:41	cfleming	Yeah, he was their senior engineer and CTO for a while.
06:41	cfleming	All those people are JetBrains employees I think.
06:42	cfleming	Ok, bedtime for me
06:43	Empperi	night
09:50	kwladyka	justin_smith is it possible to use Clojure libraries in Clojure .NET? I guess not. Clojure .NET has additional modules?
09:54	dysfun	kwladyka: anything that taps into underlying java will not be usable on .NET. you will need to find clj/clr code or write your own (or just use the .net objects directly)
09:55	dysfun	clj/clr is not commonly enough used that people really bother testing against it
09:55	kwladyka	dysfun do you have some experience with Clojure .NET?
09:55	dysfun	about five minutes before it made me want to throw my keyboard at the wall
09:55	dysfun	but that was some while ago and it may be better now
09:56	kwladyka	what was the problem?
09:56	dysfun	i may have been jesting slightly. i spent a few hours trying to get a game going on it. first with arcadia and then with unity
09:57	dysfun	i found it all a bit frustrating. the tools just aren't there yet
09:57	dysfun	clojure + emacs is an extraordinarily rich and powerful tool when configured correctly. clj/clr i don't know if cider even handles it
09:58	dysfun	and the less said about trying to hack clojure in monodevelop, the better
10:00	dysfun	the truth is that a heck of a lot of what i love about clojure comes from binding to libraries written in java
10:00	dysfun	e.g. i use aleph for a webserver. under the hood that's netty. i don't know if there even is an already wrapped webserver in clj/clr
10:03	justin_smith	dysfun: hell, I don't even know if ring works on clj/clr
10:03	dysfun	right, because nobody bothers testing it
10:04	justin_smith	dysfun: and more importantly, it uses java classes
10:04	dysfun	oh, i didn't know that
10:04	dysfun	i suppose it makes sense
10:04	justin_smith	it implements protocols over OutputStream etc.
10:05	justin_smith	I mean I bet it would be easy to port, but it hasn't been done that I know of
10:05	dysfun	"Updated on 24 Jan"
10:06	dysfun	(clojure-clr)
10:07	dysfun	https://github.com/clojure/clojure-clr/pull/8
10:07	dysfun	if it doesn't even build except on windows, it's not fit for deploying to production
10:08	dysfun	i can't help but think if that effort had gone into an llvm backend, it might have been worth it
10:10	xnapeak	Hi - I'm calling a constructor inside a Java lib, and the constructor requires casting the value nil to java.util.List<String>. Is there a way to call cast or do type-hinting with generics?
10:10	justin_smith	xnapeak: generics are fictional, but you can definitely pass a java.util.List that is empty
10:10	dysfun	there's no such thing as a generic at runtime. that is java.util.List, not java.util.List<String>
10:11	dysfun	of course if you put things other than strings in there, you get to keep the pieces
10:12	xnapeak	justin_smith It has to be nil, not empty
10:12	xnapeak	Eg. (nil? (java.util.Vector. [])) returns false
10:12	xnapeak	and just putting in nil without casting returns an IllegalArgumentException
10:12	dysfun	please show a correct java incantation for it
10:14	xnapeak	dysfun I can't find one, but here's the original source code: http://pastebin.com/FY8gYBKt
10:14	xnapeak	I'm trying to set m_Type to STRING
10:14	justin_smith	xnapeak: for that matter, clojure vectors and lists are instances of java.util.List
10:14	xnapeak	dysfun Here's an incantation in Scala: val att3 = new Attribute("att3", null.asInstanceOf[util.ArrayList[String]])
10:14	justin_smith	,(instance? java.util.List [])
10:14	clojurebot	true
10:16	dysfun	right, i see, you want null
10:16	justin_smith	nil is null though... the trick is the asInstanceOf
10:16	dysfun	yes, i see the problem
10:17	dysfun	i don't have a good answer though
10:17	justin_smith	xnapeak: scala is weird and you can't even use it from java, do you have working java?
10:17	dysfun	justin_smith: sure you can. some of it.
10:17	justin_smith	xnapeak: if you are trying to call scala from clojure, give up now, not even worth trying
10:18	dysfun	can you imagine if people started using clojure on top of the typesafe platform? hahaha
10:19	xnapeak	justin_smith Oh, I'm not using Scala at all, that was just an example of a call to that constructor I found on GitHub
10:19	dysfun	sorry, i mean "lightbend reactive platform"
10:19	xnapeak	justin_smith I don't have a Java environment set up, I could but that might take a while
10:19	justin_smith	OK - a java example would be much better
10:19	dysfun	xnapeak: lein can compile java
10:19	justin_smith	xnapeak: clojure is a great platform for using java :)
10:19	xnapeak	OK, will try to find one
10:20	dysfun	in fact lein and boot make it super easy to switch your slowest/most hit code to java
10:21	dysfun	(jmonkeyengine requires you to subclass an abstract class, for example, so you have to write a tiny bit of java if you want to use it)
10:21	xnapeak	justin_smith Okay, here's a Java call: new Attribute("content",(ArrayList<String>)null)
10:22	xnapeak	(That's is not my code, just another example I found on GitHub)
10:25	dysfun	unless justin_smith has an idea, i'm going to suggest you write that bit in java
10:25	dysfun	(using your clojure build tool to build it for you)
10:27	amalloy	(let [^List foo nil] (Whatever. foo))
10:28	xnapeak	amalloy That works. Thanks!
10:29	xnapeak	(Well, (let [^java.util.ArrayList foo nil] works, but close enough)
10:29	dysfun	amalloy: hrm, i didn't realise type hints could be used to guide method selection
10:29	dysfun	how does that work?
10:29	amalloy	that is kinda the only thing you can use them for
10:30	amalloy	select a method at compile time instead of at runtime with reflection
10:30	dysfun	oh yes, of course
10:30	dysfun	suddenly that makes sense now
10:34	Malnormalulo	Does anyone know of any good implementations of a data structure which is unordered under equality-checks (like a set), but allows duplicate members (like a list)?
10:35	Malnormalulo	(Also, does anyone know if a structure like that has a common name?)
10:35	dysfun	is it safe to assume that the namespace declaration is the first form in a clojure file if it is not missing?
10:35	dysfun	Malnormalulo: a 'bag' fits that bill
10:36	Malnormalulo	Aha, bag. Thanks, I'll look for one of those
10:36	dysfun	also known as a multiset
10:36	dysfun	essentially you can think of it as a map where the key is the item an the value is how many times it occurred
10:36	dysfun	(and that's not an unreasonable representation)
10:36	Malnormalulo	Yeah and I was thinking of just using a structure like that, but a more direct representation would be convenient
10:37	dysfun	but then you'd want a persistent one and that might take finding
10:37	dysfun	and also it wouldn't interop nicely with clojure code
10:37	amalloy	dysfun: ns should be first in a well-written program, but i don't think you should assume it actually is
10:38	Malnormalulo	also, I agree with amalloy
10:38	dysfun	the plan was to check the first sexp in the file with tools.namespace
10:39	dysfun	what would you recommend i do instead?
10:40	amalloy	why?
10:40	clojurebot	why is the ram gone
10:40	dysfun	clojurebot++
10:41	dysfun	because i'm writing a compiler that uses tools.reader to get clojure syntax for free and i need to know what namespace to read it in so syntax quote works
10:42	amalloy	so what you're reading isn't clojure source files at all, but source files for some other language that happens to use clojure lists/symbols/etc?
10:42	dysfun	yes for this one, no for my back burner clojure-to-machine-code project
10:44	dysfun	the ideal for that one is to be able to share with clojure and clojurescript in cljc files
10:46	dysfun	well formedness would be a requirement on that though, so i'm okay with bailing out if the first expression isn't an ns decl
10:55	dysfun	it also occurs to me that build.boot is not well formed by that rule
11:04	csd_	any suggestions for managing environment vars on heroku? i want to set a secret key but my .lein file doesn't get uploaded when i push to heroku as that would require putting it in my git repo
11:05	csd_	i know i can do it using the CLI tool but i'm wondering whether a better solution exists
11:05	justin_smith	csd_: I thought heroku had a command for setting environment vars directly
11:05	csd_	yeah it does through the CLI
11:05	justin_smith	csd_: ideally you would do that, then pick the value up using environ
11:06	csd_	i dont love that because i feel like it hides the var from you
11:06	justin_smith	csd_: it's hiding the var from more than just you, and that's the point
11:06	csd_	fair point
11:16	Empperi	hmm, can't get boot to read project boot.properties
11:16	Empperi	any hints?
11:16	Empperi	got the boot.properties in the same directory as my build.boot
11:16	Empperi	created the base with boot -V > boot.properties
11:16	Empperi	then edited Clojure 1.8.0 in
11:17	Empperi	but boot isn't using it
11:19	dysfun	specifically, what line did you change?
11:19	Empperi	BOOT_CLOJURE_VERSION=1.8.0
11:19	Empperi	and yes, I do know one has to define Clojure dependency to build.boot too
11:20	dysfun	hrm, what's your BOOT_VERSION ?
11:20	Empperi	BOOT_VERSION=2.5.5
11:20	dysfun	can you pastebin the output of boot -V with that properties file in place?
11:21	Empperi	no prob, altough there's nothing special except it says 1.7.0
11:21	Empperi	https://www.refheap.com/115902
11:22	Empperi	so it doesn't read the properties file
11:22	dysfun	hrm, are the permissions funny or anything?
11:22	Empperi	nope
11:22	Empperi	windows however
11:22	dysfun	ohhh
11:23	dysfun	no clue about boot on windows
11:23	Empperi	there shouldn't be anthing special
11:24	Empperi	fucking up as simple thing as reading a file from working directory cannot be something they'd do
11:24	dysfun	that's true
11:24	dysfun	and you're definitely sat in the right directory? :)
11:24	Empperi	yes
11:24	Empperi	very much so
11:25	dysfun	i'm out of ideas then. You can try #hoplon, that's where the boot guys hang out
11:25	Empperi	hmph
11:25	Empperi	yeah, guessed so
11:25	Empperi	:/
11:52	Empperi	dysfun: found out why it happened
11:52	Empperi	https://github.com/boot-clj/boot/blob/master/boot/base/src/main/java/boot/App.java#L153
11:53	Empperi	boot prefers boot.properties first from bootdir() then from projectDir() and then from workdir
11:53	Empperi	which is imho totally wierd, it should be the other way around
11:53	Empperi	weird even
11:53	Empperi	if I went to ~/.boot/ I found boot.properties from there and I modified it and now boot runs with Clojure 1.8.0
11:55	Empperi	oh right, forget about the prefer part from that. It uses HashMap... blush
11:58	dysfun	Empperi: hrm, i agree it seems like the wrong logic
11:58	Empperi	it isn't like that
11:58	Empperi	check mergeProperties at line 159
11:59	Empperi	there it iterates the properties files in order boot dir -> project dir -> cwd
11:59	Empperi	and merges the values together so that last directory should override earlier
11:59	dysfun	ohh
11:59	Empperi	but it also swallows FileNotFoundExceptions
11:59	dysfun	i see
12:00	Empperi	they should add those exceptions into debug logging or something
12:00	Empperi	now it's super hard to know wtf is going on
12:00	dysfun	er, no, because typically cwd isn't going to return one
12:00	dysfun	but it's lazy coding
12:00	Empperi	yeah
12:01	Empperi	I agree
12:01	Empperi	and to me that Java looks horrid :)
12:01	Empperi	the style it is written
12:01	Empperi	not necessarily the quality
12:01	Empperi	but that's just me
12:03	Empperi	oh well, I can go forward now since I got it running with Clojure 1.8.0
12:03	dysfun	yes, it's particularly offensive on the eyes
12:03	Empperi	I was considering to clone boot and try to find out what is happening and make a pull request but I really don't want to edit Java code which looks like that
12:03	Empperi	:)
12:03	dysfun	but i think the boot source code is a good example of why you should use clojure - to not have code that looks like that
12:04	Empperi	well, truth to be told, that is just ugly java
12:04	Empperi	good thing is that those methods are relatively small and they do only one thing
12:04	Empperi	but one could do those things much more elegantly
12:04	Empperi	in java
12:04	dysfun	yes, but one has deadlines :)
12:04	Empperi	:)
12:06	Empperi	oh well, Now I got cljs-repl to run
12:06	Empperi	couldn't get it to run with clojure 1.7.0
12:08	Empperi	any ideas on compound nrepl instances?
12:08	Empperi	I mean, now I got two nrepls running, one for clojure and one for clojurescript
12:08	Empperi	both write .nrepl-port which will cause the latter to be there only
12:09	Empperi	and besides, I don't want to connect to that repl twice unless I really want to do so
12:09	Empperi	so, it would be great if I could connect to nrepl, it would greet me with prompt like "To access clojure REPL type (clj-repl), to access ClojureScript REPL type (cljs-repl)"
12:09	Empperi	and I could jump between those two repls as I see fit
12:10	justin_smith	Empperi: you can always ignore the .nrepl-port file and just supply the port explicitly when connecting
12:10	Empperi	justin_smith: yeah, but .nrepl-port is very convenient
12:10	Empperi	one doesn't have to know what port it is running
12:11	justin_smith	I've found having two repls in emacs nothing but inconvenient
12:11	justin_smith	maybe it's improved since I gave up on repls inside emacs though
12:11	Empperi	well, one needs two with clj+cljs
12:11	Empperi	one for both
12:11	Empperi	and I use Cursive
12:11	justin_smith	oh, OK
12:12	Empperi	or well, one doesn't HAVE TO use REPL for either one but... :)
12:13	Empperi	hmm, it makes me feel like I might have a good candidate for custom boot task with that compound repl thingy
12:16	kwladyka	dysfun from what you saying i can get a conclusion maybe Clojure .NET it is bad idea and should exist?
12:24	kwladyka	*shouldnt
12:24	kwladyka	from other hand maybe it is not ready or .NET has bad community or i don't know :)
12:29	TEttinger	the CoreCLR community has been hyper-responsive in my limited bug reporting
12:29	TEttinger	really good show on some stuff that they fixed (took a while because apparently they don't use windows 7 much)
12:31	TEttinger	I do think that F# being MS-backed and IDE-supported (rather well, too) takes the motivation for using any other multicore/immutable/functional language down
12:31	TEttinger	on the CLR I mean
12:46	kwladyka	TEttinger Did you do something for production in Clojure .NET?
12:48	TEttinger	no, I did look at it enough to see it didn't have a reasonable way to work with multi-dimensional arrays though, which my existing code in C# used heavily
12:48	TEttinger	you can use jagged ones fine, but not rectangular it seems
13:00	hyPiRion	dysfun: https://en.wikipedia.org/wiki/Jagged_array
13:00	hyPiRion	In short, arrays of arrays, where the inner arrays may be of different lengths
13:00	dysfun	then how on earth if it can handle those can it not handle rectangular ones?
13:03	dysfun	hyPiRion: damnit i've fallen down a wikipedia hole because of you
13:09	hyPiRion	I guess it depends on how the rectangular arrays are implemented.
13:10	hyPiRion	Usually they are just a single block of memory for performance reasons, whereas a jagged one is an array of array pointers
13:14	csd_	any suggestions how you would remove the conditional nesting in this snippet http://pastebin.com/546s0ZQt ? i'm interested in checking out the cats category theory library and using `maybe`. not sure how well that would work because of the db calls though
13:25	TEttinger	hyPiRion: dysfun: they're different types on the CLR.
13:26	TEttinger	.NET and Mono allow you to do "new int[40,20,10];", which helps since they don't have the all-at-once jagged array initializer in Java like "new int[40][20][10];"
13:27	TEttinger	you can still do "new int[40][][];"
13:27	TEttinger	and then assign different or the same lengths to members
13:34	gilch	dysfun: I've been using jMonkey Engine without writing Java so far. What would you need it for?
13:35	dysfun	i don't remember any more. i think it was to do with certain features only being available if you used this abstract class interface
13:38	gilch	clojure can use proxy to make an anonymous subclass of a java class
13:39	gilch	It can't access protected members, but you can use reflection for that, or even gen-class if you compile ahead of time
13:39	dysfun	ah yes
13:42	gilch	I think most protected fields in jME that you would care about have public accessor methods anyway.
13:43	dysfun	i didn't play with it much, it was just something i remembered about it from a while ago
14:18	WickedShell	This has to be a stupid question but whats the standard protocol that I need to implement on my records to get meaningful results for when toString or (str ) is called on a record?
14:19	justin_smith	WickedShell: toString method on Object, but really records usually print nicely, deftype on the other hand will need help
14:20	WickedShell	they just keep printing their name and a pointer IE "swiftgcs.utilities.Waypoint@c050c63c"
14:20	justin_smith	then toString is not what is being called, or it isn't created with defrecord
14:21	WickedShell	it's being created with a (str "desc " record-here)
14:22	justin_smith	hmm - maybe I'm wrong about toString - try implementing it eg. (defrecord Foo [] Object (toString [this] ...))
14:22	WickedShell	and its a defrecord, with the actual instance made with (new RecordName field1 field2 etc)
14:22	justin_smith	(defrecord Foo [] Object (toString [this] "this is a foo"))
14:22	justin_smith	,(defrecord Foo [] Object (toString [this] "this is a foo"))
14:23	clojurebot	sandbox.Foo
14:23	justin_smith	,(str (new Foo))
14:23	clojurebot	"this is a foo"
14:23	justin_smith	,(defrecord Foo [] Object (toString [this] (pr-str this)))
14:23	clojurebot	sandbox.Foo
14:23	justin_smith	,(str (new Foo))
14:23	clojurebot	"#sandbox.Foo{}"
14:24	irctc	hi guys. anybody here?
14:24	justin_smith	always
14:24	irctc	cool
14:25	WickedShell	justin_smith, thanks that looks like exactly the behavior I'm looking for
14:26	justin_smith	awesome
14:26	irctc	I've been looking at clojure on and off over the last couple of months but I've not clue what this does: (def ^:dynamic re-password #"^(?=.*\d).{4,8}$")
14:26	irctc	actually it's just the ^:dynamic bit that's not clear to me
14:26	justin_smith	it defines a thread-bound var, and the root binding is a regex
14:27	justin_smith	irctc: dynamic vars can carry a different value in each thread
14:27	justin_smith	use them with binding
14:27	justin_smith	,(doc binding)
14:27	clojurebot	"([bindings & body]); binding => var-symbol init-expr Creates new bindings for the (already-existing) vars, with the supplied initial values, executes the exprs in an implicit do, then re-establishes the bindings that existed before. The new bindings are made in parallel (unlike let); all init-exprs are evaluated before the vars are bound to their new values."
14:28	justin_smith	also, futures inherit dynamic vars from their calling thread
14:28	irctc	@justin_smith. thanks. I think I get it. Not sure why it would be needed in this specific case...
16:24	CaptainLex	So, if I have a function foo
16:24	CaptainLex	and a function bar that calls foo
16:24	CaptainLex	and I re defn foo in a repl session
16:25	CaptainLex	Does bar call the old or the new version of foo?
16:25	justin_smith	CaptainLex: depends how bar was defined - if bar was a defn yes, if defined using eg. comp, perhaps not
16:27	CaptainLex	justin_smith: Yes, I see. I wonder what else is going on here...
16:27	justin_smith	the difference is whether a first class function was used.
16:27	justin_smith	the most common cause of this is that someone runs something like (start-server foo) - where foo is a first class function argument
16:28	justin_smith	that won't see any change in the var #'foo
16:29	CaptainLex	Interesting. That's because when it gets passed, it doesn't care about the identifier anymore? And is there any alternative way to cause this kind of behavior?
16:30	CaptainLex	I suppose it would to only /pass/ thin wrapper functions that call the functions you want re-eval?
16:30	justin_smith	CaptainLex: simpler is to pass the var
16:30	justin_smith	if you run (start-server #'foo) it will deref the var each time it uses it, instead of caching the value
16:31	justin_smith	this is because when you call a var, the var looks up its own contents and calls that with the same args
16:31	justin_smith	,(#'+ 1 2 3)
16:31	clojurebot	6
16:31	CaptainLex	justin_smith: Whoa, yeah
16:31	CaptainLex	That's awesome
16:31	CaptainLex	Thanks!
16:32	CaptainLex	Also that explains things I've seen in other projects I've worked on
16:32	justin_smith	definitely a cantidate for a faq entry
17:34	duck1123	Does anyone know why I would be getting a Invalid :refer error when compiling cljs in a docker container, but not outside?
18:39	rhg135	I tried to write a blog post about it, justin_smith, but it might not help
18:40	rhg135	http://www.rhg135.com/posts/2015-08-23-var-or-fn.html
18:44	rhg135	It seems a very frequent question
18:49	rhg135	Compiler version perhaps, duck1123
18:50	justin_smith	also I'd compare dependency versions in general, and also make sure build targets have been cleaned since the last change - cljs has bad caching logic sometimes when it tries to incrementally build
19:47	michaelrose	ok dumb question I thought you needed to install templates somehow so figured you had to clone the repo for the template in question and do lein install in that dir which appears to have been utterly uneccesary
19:48	michaelrose	if I understand properly all the lein install actually did was download the proper files to ~/.m2/dir
19:49	justin_smith	michaelrose: right, and it would do that anyway if you just used lein new with the template
19:49	justin_smith	michaelrose: but! that does avoid the problem I have with templates, which is that they are unversioned (and this tends to break internet tutorials, which is a problem)
19:49	michaelrose	so I didn't mess up anything which is good
19:50	justin_smith	heh, sure
19:50	michaelrose	oh so basically manually installing it would ensure I could grab it at a known point
19:50	justin_smith	now that I say that, I wonder if lein wouldn't look for the latest anyway regardless...
19:50	michaelrose	whereas if I had just done lein new name it would grab the latest available
19:51	michaelrose	that should be easy to test
19:55	michaelrose	justin_smith, it does not
19:58	rhg135	that is awesome-ish