#clojure – 2014-10-06

2014-10-06

01:47	jergason	is there a way to specify that I just want the latest version of a dependency in my project.clj file? putting * didn't work
01:50	Kneiva	"I really don't recommend this practice (nor using version ranges) for the sake of build reproducibility. A build that starts to suddenly fail for an unknown reason is way more annoying than updating manually a version number." - Pascal Thivent
01:50	Kneiva	that's from here: http://stackoverflow.com/questions/30571/how-do-i-tell-maven-to-use-the-latest-version-of-a-dependency
01:52	sm0ke	in clojurescript i have an atom a and would like to attach a callback to it when it becomes true, whats the sane way to do that?
01:53	Kneiva	jergason: but if you really want to do it: http://stackoverflow.com/a/5698227/1790621
01:53	Kneiva	jergason: oh, that might be outdated
01:53	jergason	Kneiva: ah, i didn't know it used maven under the hood. i'm pretty new to the jvm
02:54	mercwithamouth	ping
03:04	Guest80083	pong
03:46	mercwithamouth	ok all of a sudden cider-jack-in stopped working. i'm geting a lein execuable isn't on exec-path
03:46	mercwithamouth	i've never had that issue before...
03:50	daniel___	looking for a clojure way of solving this problem: https://gist.github.com/danielstockton/419abc82332703edc230
03:52	daniel___	seems tricky to avoid stackoverflow errors
04:00	mercwithamouth	any cider guys here? getting an error when repl starts http://pastie.org/9624243
04:00	mercwithamouth	more than likely clojure--prettify-symbols-alist should have a single '-'???
04:00	lazybot	mercwithamouth: How could that be wrong?
04:00	snowstalker	mercwithamouth I have no idea what that could be, but can you check if cider-nrepl and cider are both the same version (e.g. 0.7.0)?
04:01	mercwithamouth	yeah..checking now
04:02	mercwithamouth	hmm cider is 8.0
04:02	mercwithamouth	not sure when the hell it updated....
04:04	mercwithamouth	ok going to remove and load the stable
04:26	daniel___	how would people solve this as a 4clojure type challenge? https://gist.github.com/danielstockton/419abc82332703edc230
04:27	mercwithamouth	light table or emacs?
04:28	daniel___	vim
04:29	mercwithamouth	=P i used vim for years
04:33	engblom	Speaking about editors and IDEs: If you were in the situation you got 12x45min to teach an elementary school class basics about Clojure and having no time to teach them an editor at the same time, what would you recommend?
04:35	daniel___	engblom: sublime or something?
04:35	engblom	I looked at nightcode but it does not have rainbow parenthesis by default making it more difficult for the kids. Otherwise it would be perfect for this situation as it has REPL and loading the code to REPL built in.
04:39	magopian	daniel___: dunno how to solve your problem, but i'd love to, so if you find the solution, please share ;)
04:40	magopian	given the number of cases to explore (factorial 26 right?), it looks like something NP
04:40	magopian	even if you can trivially drop some of the cases to explore, you still have soooo many...
04:41	daniel___	magopian: it is NP, its basically the knapsack problem
04:42	magopian	yeah
04:42	clojurebot	Gabh mo leithscéal?
04:42	daniel___	magopian, i think the idea is to build a tree from all the numbers which has all the less than numbers as children and traverse it, probably some ways to prune it
04:45	borkdude	engblom I think for just one simple workshop this can be great https://github.com/bodil/catnip
04:49	engblom	borkdude: Thanks, I will check it up!
04:49	code2learn	hi, i am start learning clojure
04:49	borkdude	engblom however, you need to install leiningen on their system etc. Intellij + cursive might be a good option too
04:50	code2learn	and want to know anyone knows how to use overtone.at-at
04:51	code2learn	i am building a simple program to keep polling ebay
04:51	cfleming	engblom: I develop Cursive, if you'd like help with that or you have questions, feel free to ask, either here or on cursive@cursiveclojure.com
04:51	cfleming	engblom: You should also take a look at Light Table
04:53	code2learn	and let the program notify me whenever a needed item appears on ebay and matches with my price
04:55	engblom	cfleming: When looking at the home page of Cursive, it looks like it will become just a commercial product. Is that the case?
04:55	cfleming	engblom: It will at some point, yes.
04:56	borkdude	cfleming maybe you can release a simple free version with the cool things disabled
04:56	cfleming	borkdude: I'm definitely thinking about this, or maybe even with most of the cool parts but just a license forbidding commercial work.
04:57	cfleming	borkdude: That would work for both academic + OSS
04:57	cfleming	borkdude: I guess some people would take advantage of it, but it might be worth it. I'd like as many people as possible to be able to use it.
04:57	borkdude	cfleming intellij uses this model also right
04:57	borkdude	cfleming e.g. no highlighting for many things in free
04:58	cfleming	borkdude: Right, but you have to apply to them for a free license.
04:58	cfleming	borkdude: Oh, that's different.
04:58	borkdude	cfleming yeah, when I was a lecturer I used Pycharm etc. for free
04:58	cfleming	borkdude: Community edition is free, right. That does all you want for Java unless you need the enterprise stuff.
04:58	cfleming	borkdude: But you can get free versions of Ultimate, or right, PyCharm etc, but you have to apply for them.
04:59	cfleming	borkdude: I don't have bandwidth to administer that so I was considering an honesty model.
05:00	borkdude	cfleming or a trial version for x days
05:00	cfleming	borkdude: Yes, I'll definitely do that either way.
05:01	engblom	Personally I want cross platform solution any kid could install at home. The school is running Debian and most kids have Windows at home.
05:01	engblom	If it is too difficult to obtain and install, they will never do it.
05:02	cfleming	engblom: Right, Cursive will work like that. I'm planning (or at least thinking seriously about) a free version for academic use, but I'm busy right now and I haven't finalised the details.
05:02	borkdude	engblom have you also looked at eclipse + counterclockwise, it's entirely open source/free
05:02	cfleming	engblom: If that uncertainty is a problem for you, I think you should check out LightTable.
05:03	borkdude	engblom I have used eclipse + ccw in education
05:03	borkdude	engblom not kids though
05:05	mercwithamouth	should this be all i need to display my html file with compojure? http://pastie.org/9624332
05:06	cfleming	engblom: Take a look at Cursive and try it out - if you'd like to use it drop me a mail, I'm sure we can work something out.
05:07	engblom	cfleming: So how do I download it?
05:07	borkdude	engblom download the intellij community edition
05:07	borkdude	engblom and then via the cursive site you'll find instructions how to add the plugin
05:08	cfleming	engblom: There are instructions here: https://cursiveclojure.com/userguide/
05:08	sindu	daniel___: it's a knapsack problem.. if you try to solve it with DP (dynamic programming), you'll need an array of 2x100 000 000 with running time of 26x100 000 000
05:09	cfleming	engblom: But if you're looking for the simplest thing possible, I think Light Table is for you - take a look at both of them and see what you think.
05:09	asQuirreL	amalloy, hey, I don't know if you remember me, but I was the person who asked about the map with unusual shared value properties. I have a solution for it, so I figured I'd show you it as it explains what I wanted better than I could: http://hastebin.com/exuwayutik.clj
05:09	sindu	basically you have 2 nested loops, outer loop is iterating state, inner loop iterates 1..100 000 000, and as you go you update array[i]=true if array[i-state] is true
05:11	sindu	the idea is array[i] represents whether it's possible to have a sum of i
05:14	mercwithamouth	sweet..got it =P
05:14	daniel___	sindu, i'd rather try and solve it in a functional way
05:15	daniel___	my attempt is recursive and consumes all the heap space though https://gist.github.com/danielstockton/043a3d3093e90ba55657
05:51	lgrapenthin	I'm having trouble with using profiles and uberjar in leiningen: lein with-profiles +dev uberjar does not include dev dependencies in the uberjar
05:52	Cr8	tried pruning as I generated permutations, I run out of memory p quick tho
05:53	hellofunk	in Om, what is the scope of a #js :ref? It appears to be known only within the Om component that sets it, is that right?
05:54	Cr8	course if you just want the answer, the search space is actually not that large
05:55	ddellacosta	hellofunk: yeah, it's within the component to the best of my knowledge. Children certainly can't see a parent's ref, which I know because it bit me yesterday when I was splitting a component out from its parent.
05:55	hellofunk	ddellacosta and it also appears that siblings and parents cannot see children's refs
05:56	ddellacosta	hellofunk: in general, if you don't explicitly pass something down it won't be shared, as far as I know.
05:56	Cr8	found in haskell w/ brute force in ~30s
05:58	hellofunk	ddellacosta some some wild photos on cnn from tokyo today
05:59	ddellacosta	hellofunk: oh, the Typhoon? I've avoided going out, although it got sunny halfway through the day, so I did laundry...haha
05:59	hellofunk	nice
05:59	ddellacosta	:-)
05:59	hellofunk	ddellacosta are you writing an Om cookbook? or do you have a nice public place with all your collected notes and tips?
06:00	ddellacosta	hellofunk: oh, if you're referring to that repo, I'm just collecting stuff as I see questions come up on the mailing list, and as I think of stuff I don't know how to do yet or which seems like it'd be good to share
06:00	magopian	while you're talking about om and cookbooks and stuff, i'm planning on a "shared discovery" of om with a few others over the internet (google hangout I guess)
06:00	ddellacosta	magopian: neat, sounds cool
06:01	magopian	i've been through the basic tutorial and a few others, any advice on what to try/trial/play with, and what form?
06:01	magopian	ddellacosta: dunno if it'll be cool or not, i'm not going to "teach" anything, because i don't know anything, it's just me and maybe two or three others willing to give it a shot, together :)
06:01	magopian	(but remotely ;)
06:01	ddellacosta	magopian: still good stuff, learning together like that is great!
06:01	magopian	it's an experiment, we'll see if it's worth it
06:01	annapawlicka	magopian ddellacosta that would be awesome
06:02	magopian	nice if you think it's a good idea ;
06:02	magopian	);)
06:02	hellofunk	magopian i think the best way is to just build out a simple app with Om, then all the concepts fall into place. doing something original vs. following a tutorial makes you exercise your knowledge of how to apply the techniques.
06:02	ddellacosta	magopian: as far as advice, I'm biased because I use Om every day for work, and for me working on a big project was really educational, so I would suggest...working on a project.
06:02	ddellacosta	or, what hellofunk says ^
06:02	magopian	so any advice on what to do during this session? I think it'll be rather short (maybe an hour? or two?), and I think some of the people won't have previous clojure knowledge at all (I only have a very small knowledge of it myself)
06:02	ddellacosta	and maybe annapawlicka has thoughts too...
06:03	ddellacosta	magopian: well, be careful not to get stuck on Clojure stuff
06:03	hellofunk	magopian i also recommend core.async involved as I don't think it is possible to write a really tight Om app without it
06:03	magopian	ddellacosta: yeah, that would be annoying, I have to come up with a dead simple project, and at least have an idea of how to implement it beforehand I guess
06:04	ddellacosta	magopian: if you are working with beginners basic Clojure questions may end up taking over, and Om really uses a fair number of advanced Clojure/CLJS concepts, so may be good to start by going over some basic Clojure stuff.
06:04	magopian	hellofunk: yeah, i'd like to add some of this (i've seen the screencast by swannodette, and it was awesome)
06:04	annapawlicka	all the gotchas usually come up during big projects and i tend to make notes like "don't ever do x", "remember to do x" etc.
06:04	magopian	not just sure how to fit all this in a one (or two?) hour slot
06:04	ddellacosta	magopian: yeah, if you can get the basics of Om across without getting mired in Clojure stuff that'd be great
06:04	ddellacosta	oh yeah, annapawlicka had a blog post about that, probably good to pass that around
06:04	hellofunk	magopian honestly i don't think Om is an appropriate topic for those quite new to clojure or clojurescript.
06:05	magopian	hellofunk: ahhh, interesting point of view
06:05	magopian	ddellacosta: do you have a link?
06:05	annapawlicka	i shoudl probably write part ii of that post
06:05	ddellacosta	hellofunk: it's a mixed bag, right? I think that it's got a lot of momentum and that may carry beginners over the hump, so to speak
06:05	magopian	ddellacosta: hellofunk: i thought about om because i'm interested in it myself, and because the two others are interested in frontend dev
06:05	hellofunk	ddellacosta: i will say this, using Om helped solidify for me how reification and protocols work, as otherwise i'd have not used them probably ever
06:06	ddellacosta	annapawlicka: yes, you should. ;-)
06:06	magopian	(ember.js and angular, iirc)
06:06	ddellacosta	hellofunk: yeah, for example--those two are big in Om
06:06	magopian	ddellacosta: but then I could use prismatic's om-tools, and don't touch reification at all ;)
06:06	magopian	and use a simple enough project to not have to deal with protocols (which i still find pretty hard to grok)
06:07	ddellacosta	magopian: yeah, I dunno, that's reasonable too I suppose
06:08	ddellacosta	magopian: I don't think there's a perfect answer but I think regardless of what you do, come up with a specific project to work through and give it to folks beforehand, if possible
06:08	magopian	i need to find a nice and dead simple project, maybe something like a todolist
06:08	annapawlicka	i hear reagent is easier for beginners. but i wouldn't even try to explain wrappers like these to beginners. it'd be easier to just show core.async and how to wire it with events, while building a simple web app
06:08	magopian	or just a counter, or something really really really simple
06:08	ddellacosta	magopian: well then, funny that you mention that, I think there is a good todo list built in Om... ;-)
06:09	magopian	because i'll have to give a short overview of clojure for starters
06:09	magopian	ddellacosta: yeah, the todolist mvc by swannodette?
06:09	ddellacosta	magopian: have you taken a look at the examples that David packages w/Om? there is a simple selection thing in there if I recall
06:09	ddellacosta	magopian: yeah, that's what I was thinking of
06:09	hellofunk	magopian to really understand Om I think working with it directly is most educational. using other tools to abstract it only gets further from understanding how it works. for example, I like using the #js and (apply dom/div...) techniques, and using (reify...) because it's easier to know what's really happening
06:10	magopian	hellofunk: but then it needs an understanding of the reader macros and reification
06:11	ddellacosta	magopian: here is annapawlicka's post about common Om mistakes, btw: http://annapawlicka.com/common-mistakes-to-avoid-when-creating-an-om-component-part-1/
06:11	hellofunk	magopian -- there is a risk that someone who sees all this for the first time, including Om helper tools, will not know which is Om and which is something else.
06:11	ddellacosta	hellofunk: yeah, kind of hard to avoid that
06:11	ddellacosta	I mean, there is a learning curve to all of this
06:11	jonathanj	does anyone here use plugins in vim for editing clojure code?
06:12	hellofunk	a while back there was a comment from Nolen on google cljs group about how closures in cljs are not "free" and take a performance hit. does this mean that (let [f #(something...)] (f...)) is not wise in cljs functions?
06:12	jonathanj	i'm having trouble understanding how paredit is missing a feature that moves down or up a form
06:12	hellofunk	he suggested "breaking out the helpers" so they weren't defined inside another function
06:12	jonathanj	ie. something like f( but less stupid
06:12	hellofunk	jonathanj which ide?
06:13	jonathanj	vim?
06:13	clojurebot	Gesundheit!
06:13	ddellacosta	ah, hahaha
06:13	ddellacosta	you snarky clojurebot you
06:13	ddellacosta	,(println "is hiredman still not responding to me?")
06:13	clojurebot	eval service is offline
06:13	ddellacosta	yep
06:14	xcthulhu	hellofunk: What kind of performance hit? You might have to checkout jsperf to get any real sense of anything
06:14	hellofunk	xcthulhu i'm not sure what he was referrign to
06:14	xcthulhu	Spidermonkey and V8 have very different performance profiles for this sort of thing
06:15	jonathanj	it seems insane to me that there's no motion for moving down and up forms
06:15	xcthulhu	% goes to matching paren, usually all I use
06:15	xcthulhu	Since it has been a feature of VI since before I was born, I understnad
06:16	jonathanj	that's not usually very useful
06:16	jonathanj	if you're on (defn then % takes you to the end of the function, whereas usually you want to start navigating in to the function
06:17	mercwithamouth	not really a clojure question but....postgres or mysql?
06:17	xcthulhu	postgres
06:17	schmir	postgres
06:18	xcthulhu	You can use datomic with postgres as a backend...
06:18	mercwithamouth	i'm making a toy bookmark app...with allows you to attach notes to your bookmarks...as well as create containers with 'like' bookmarks and carry conversations on the given topic with friends
06:18	mercwithamouth	xcthulhu: heh...i've been debating on trying that...
06:19	xcthulhu	You should give it a shot, it’s awesome
06:19	mercwithamouth	i almost think 'redis' would be really cool for what i want as well...but i really want to get a handle on SQL opposed to continuing to play with all of these new databases...
06:19	xcthulhu	Plus, in memory testing is pretty sweet, but you can do that with h2 as well if you don’t write really funky SQL schemas
06:19	magopian	hellofunk: ah, that's true, about not knowing what is om and what is om-tools
06:20	mercwithamouth	sigh...so datomic...i suppose i could advance the project to some sort of bookmarking/studying tool
06:21	xcthulhu	mercwithamouth: Since it’s a toy app, what do you want to learn exactly?
06:22	xcthulhu	Migrations?
06:22	mercwithamouth	really i'm just toying with compojure and eventually 'om'
06:22	mercwithamouth	i wouldn't mind putting it up publicly in time for my friends and I to use. the idea isn't 'solid' yet though.
06:23	magopian	hellofunk: ddellacosta: annapawlicka: anyway, thanks a lot for your feedback and encouragements, i'll let you know how it went (if I manage to pull it out ;)
06:23	ddellacosta	magopian: good luck! And have fun. :-)
06:23	magopian	4;3~thanks ;)
06:24	xcthulhu	If you have the bandwidth, I say checkout datomic
06:25	xcthulhu	Especially if you want to have your database behave like a graph
06:26	xcthulhu	Which sounds vaguely like what you want to do
06:27	hellofunk	ddellacosta: annapawlicka: what are the common sources of js memory leaks you see from using Om/cljs?
06:28	ddellacosta	hellofunk: not sure I've seen Om-specific memory leaks
06:28	annapawlicka	hellofunk: what ddellacosta said
06:29	hellofunk	i wonder if the cljs closures are giving me the leaks i see. have yet to do robust profiling
06:29	ddellacosta	hellofunk: a clojure in and of itself shouldn't cause a memory leak, just depends on how you're using it
06:29	ddellacosta	hellofunk: er... *closure
06:33	hellofunk	ddellacosta ok
06:34	amalloy	leaking dom nodes? that happens all the time in js, doesn't it?
06:34	ddellacosta	amalloy: sure, just not sure there is anything specific to Om there
06:34	ddellacosta	not that I know of at least. May be.
06:35	amalloy	no, but hellofunk didn't say om-specific, just "when using om"
06:35	ddellacosta	amalloy: okay, fair enough. :-)
06:37	daniel___	amalloy, you like a good problem
06:37	daniel___	might be one for 4clojure
06:37	daniel___	https://gist.github.com/danielstockton/043a3d3093e90ba55657
06:37	daniel___	i havent come up with a solution yet
06:38	amalloy	i actually was just starting on that
06:39	amalloy	it looks kinda like the knapsack problem, really, but might be tractable at that size
06:44	daniel___	im not really sure how to do it without a brute force type approach, and always run out of heap space
06:47	xcthulhu	Well, so don’t brute force it
06:47	xcthulhu	As you go along, picking populations, keep a running sum
06:48	xcthulhu	If the running sum gets too big, don’t follow that branch
06:48	amalloy	xcthulhu: that's still pretty brute-force, and the first thing i tried
06:48	amalloy	you're still in the position of trying to solve the knapsack problem with the greedy algorithm :P
06:50	xcthulhu	You have to do backtrack search, but you don’t keep every path in memory, right?
06:51	xcthulhu	Okay, I guess this is what you are doing
06:52	amalloy	xcthulhu: even if memory weren't an issue, 2^26 is a large enough search space that you need more clever pruning
06:52	amalloy	just removing the most obviously-impossible stuff isn't good enough
06:52	xcthulhu	grumble back to depth first forests :(
06:53	xcthulhu	Or you could be dumber than that and try annealing?
06:54	xcthulhu	Doesn’t seem like an annealing problem
06:54	xcthulhu	You should use this as a cruel interview question
06:55	amalloy	daniel___: https://gist.github.com/amalloy/70c58e289de9e892468d is the obvious approach that xcthulhu and i thought of first
06:56	amalloy	but i think this is basically a special case of a well-known NP-hard problem, so unless you have some reason to believe that this special case has a neat trick to it, i'd guess you can't really do anything
06:56	amalloy	so, that's all from me and i'm off to bed. let me know if you figure out the trick
06:57	Johannes`	hi, when I run http://pastebin.com/t7wqhBCW in the REPL, the loop form is executed before the dotimes form. why is this?
06:59	daniel___	amalloy_: no, i have no reason to suspect there is a neat trick
07:01	Johannes`	dotimes only runs after (get-number) has returned
07:06	daniel___	i still get a java heap space error with this algo, maybe i need to configure something on the jvm to allow more memory?
07:07	daniel___	anyway, nn
07:30	noncom\|2	i remember recently talking to someone here about dynamically compile and load a java class from leins :java-sources.. and i was told that this is impossible due to jvm limitations, however, i have found some sources that suggest that this is possible.. so what is true of this ?
07:41	perplexa	noncom\|2: sounds like real bad application architecture in first place
07:42	noncom\|2	perplexa: security and stuff, exceptions and stuff, right.. but that is for a sandbox, so i think that it is acceptable..
07:44	perplexa	i don't see what speaks against having it in your source all the time. maybe have a look at leiningen profiles when you need specific resources only in certain environment
07:44	perplexa	+s
07:45	noncom\|2	perplexa: i want to have a persistant clojure repl running, with possibility to reload classes from their source files..
07:45	noncom\|2	i know that sounds creepy
07:45	noncom\|2	for many reasons
07:46	noncom\|2	but i want to let java-only devs to write plugins to the program too, being able to change them in runtime, without restarting the program
07:46	noncom\|2	it is supposed that the users realize all the risks and take the necessary care..
07:47	perplexa	hm i don't know how to do that, sorry
07:47	perplexa	good luck, tho
07:56	dysfun	it's not trivially solveable for java. you need something like jrebel for that
07:56	dysfun	or some clever ide integration
08:05	dysfun	can i make a keyword function part of a protocol?
08:06	dysfun	it seems like an ugly solution
08:06	dysfun	no. i can imagine why
08:06	CookedGryphon	noncom\|2: it's totally possible to compile and load java classes at runtime, I remember doing it for a uni project once, it just ran javac on command and then did forName with a custom classloader
08:08	dysfun	reload is a little harder
08:15	noncom\|2	yeah, well, ok... i imagine i can compile and load a class, but what about recompile and reload ?
08:21	szymanowski	hello, i'm searching a way of overwriting object's method while keeping all others methods as is
08:22	szymanowski	overwriting an object's method
08:22	szymanowski	is it possible with proxy?
08:30	agarman	noncom\|2: you can reload by swapping classloaders
08:30	agarman	noncom\|2: if you load the class through your apps primary classloader, you'll have a hard time reloading
08:35	noncom\|2	agarman: so you're saying that i just have to create a custom classloader for every reload operation ?
08:36	agarman	noncom\|2: pretty much, if you need to load a class with the same FQ name as an already loaded class, you can only do that inside another classloader
08:37	noncom\|2	agarman: thank you, this is a very valuable piece of info !
08:37	agarman	noncom\|2: good luck
08:38	agarman	noncom\|2: https://github.com/zeroturnaround/jf-hw-classloaders may be relevant to what you're wanting to do
08:41	noncom\|2	yes, really, that's it
08:41	agarman	noncom\|2: ^_^
09:59	grandy___	hello, just working with reagent and secretary, and wondering if there is a recommended way to handle updating window.location after calling secretary/dispatch! to navigate to a different route handler?
10:02	AeroNotix_	https://gist.github.com/AeroNotix/1c669b4af6fedf952e63
10:02	AeroNotix_	any ideas?
10:07	justin_smith	AeroNotix_: maybe run lein clean and try again?
10:07	justin_smith	weird that it would be trying to include something in the "stale" directory
10:07	AeroNotix_	justin_smith: it's a permissions issue
10:07	AeroNotix_	It's building in a directory it doesn't have permissions for
10:07	AeroNotix_	excellent handling of that though
10:09	clgv	AeroNotix_: file an issue for it.
10:10	AeroNotix_	clgv: need to fully understand it first
10:10	necronian	Is there a reason to wrap a function in a empty (let []) like in this start-server function in the rook documentation? http://howardlewisship.com/io.aviso/documentation/rook/dev.html
10:10	AeroNotix_	fuuuuuuuuuuuck and that host just got deleted
10:12	AeroNotix_	clgv: well I can't debug that now https://github.com/technomancy/leiningen/issues/1724 created an issue for it
10:12	clgv	necronian: usually no. in Clojure's implementation there is a scenario though where (let [] ...) is used instead of (do ...) - I dont remember the exact explanation for that one right now
10:13	clgv	AeroNotix_: you should specify that you want a better error message there ;)
10:14	AeroNotix_	clgv: I should hope that's obvious
10:15	clgv	AeroNotix_: well, the point of issues is to be as specific as possible so no implicit knowledge is require to work on it
10:16	necronian	clgv: Thanks, so it's probably just an accident. I was thinking maybe there was some sort of magic happening I didn't understand.
10:16	clgv	AeroNotix_: right now your ticket could be closed with "This exception is expected."
10:17	clgv	necronian: yeah, maybe they had some local bindings in an earlier version of those snippet
10:17	AeroNotix_	clgv: clearly the exception should be raised when it couldn't write the file that it later expects it to be there?
10:18	AeroNotix_	clgv: I'd love to be a neckbeard with you all day but there is other software that I more urgently need to pretend to care about.
10:18	AeroNotix_	clgv: we'll catch up later.
10:18	clgv	AeroNotix_: just specify what you think is wrong with the behaviour you described or be disappointed if it just sits there unresolved ;)
10:19	AeroNotix_	clgv: I don't have time right
10:36	ben_m	Hey everyone. Is there something like a map with default values for collections that ran out before the longest one? As opposed to map which stops when one collection is done.
10:37	clgv	ben_m: not in clojure.core
10:38	ben_m	Too bad, I'll have to think of another way then :)
10:38	clgv	ben_m: but you can write it yourself pretty easily, just adapt the implementation of `map`
10:39	ben_m	There's likely a better solution, I'm just approaching this weirdly.
10:40	clgv	ben_m: you just need a `some` instead of the `every?` there https://github.com/clojure/clojure/blob/master/src/clj/clojure/core.clj#L2631
10:41	clgv	ben_m: `or` instead of `and` in the 2/3 arity cases
10:41	ben_m	I have a graph in a triangle shape where the nodes on a row connect to both nodes below it. Trying to write a function that, given two rows, returns all the paths.
10:41	clgv	then you'll get `nil` and just need to insert the default value instead
10:41	ben_m	clgv: Writing that function wouldn't be a problem, I just feel like there's a nicer way of doing what I described.
10:41	ben_m	But thanks :)
10:41	borkdude	do many people use :pre and :post in clojure functions?
10:41	borkdude	I haven't used them much
10:42	borkdude	but maybe I should
10:42	justin_smith	ben_m: sounds like a 4clojure problem I've seen
10:42	clgv	borkdude: I always was not sure if I could turn them off in a production release ;)
10:42	ben_m	justin_smith: Project Euler, that's why I'm intentionally not just stating the full problem :D
10:42	borkdude	clgv and are you sure now?
10:43	justin_smith	ben_m: you can do that kind of combinatorial thing with recursive calls to mapcat
10:43	justin_smith	ben_m: mapcat because each input element can become 0 or more output elements (as opposed to 1:1 with map)
10:44	ben_m	I did it using mapcat and then regrouping using group-by, but that's kind of ugly.
10:44	ben_m	But I'll spend some more time thinking about this, maybe the data structure I want out of this isn't optimal in the first place.
10:45	justin_smith	I would think there is a mapcat variation without group-by
10:46	ben_m	justin_smith: This is what I'm trying to write currently http://sprunge.us/WNCK
10:48	ben_m	Better paste http://sprunge.us/XZgU
10:49	ben_m	Almost there.
10:49	justin_smith	ben_m: haha, looking back at the triangle thing I solved on 4clojure, I actually used a graph algorithm, making a vertex out of each number, and edges representing valid paths (this was for a minimal path algorithm)
10:50	justin_smith	which works, and is reasonably efficient, but like many graph algorithms is definitely not the most concise way to solve the problem
10:50	ben_m	justin_smith: This problem has me calculate the maximum path (each node is a value) from top to bottom. I'm going through it row by row and collect the best path to each node, then recurse with the rest of the triangle/graph.
10:50	justin_smith	ben_m: same problem then :)
10:51	daniel___	who likes challenges? https://gist.github.com/danielstockton/043a3d3093e90ba55657
10:51	daniel___	keep getting stackoverflow errors
10:52	justin_smith	concat will do that
10:52	justin_smith	what happens is the laziness causes multiple calls to concat to stack up
10:52	justin_smith	and by the time you force the laziness, it explodes on the stack
10:52	daniel___	mhm
10:52	daniel___	lazy-cat?
10:54	justin_smith	I don't think lazy-cat will help here - in fact the stacked up laziness is a big part of the problem
10:54	daniel___	it did :D
10:54	daniel___	did i just get lucky?
10:54	justin_smith	oh, I guess I was wrong
10:54	daniel___	yeah, seems to work
10:54	daniel___	i think its the fact it means the recursive call is lazy?
10:54	justin_smith	I don't really get how lazy-cat avoids the concat pileup problem, but if it does, great
10:55	daniel___	its the pile up of summing-to perhaps
10:55	justin_smith	could be the way laziness linearizes recursion into thunks representing the next step
10:58	clgv	borkdude: no, not really
11:10	justin_smith	clgv: borkdude: "By default, assertions are disabled at runtime. Two command-line switches allow you to selectively enable or disable assertions. ... -ea ... -da" http://docs.oracle.com/javase/7/docs/technotes/guides/language/assert.html
11:12	clgv	justin_smith: what does that mean for clojure's :pre :post? they are usually enabled by default
11:12	justin_smith	they generate assertions, when you make a jar, java decides whether assertions are run
11:12	justin_smith	clojure uses jvm native assertions, they are a feature the vm controls
11:13	clgv	justin_smith: but are you sure that's the same mechanism since it says "by default disabled"
11:13	justin_smith	when you run java -jar, yes, disabled
11:13	justin_smith	hmm - now I see your point
11:14	justin_smith	http://stackoverflow.com/questions/24949418/how-to-disable-clojure-assertions-including-preconditions
11:14	justin_smith	,assert
11:14	clojurebot	true
11:14	justin_smith	there we go
11:14	borkdude	I wish I could make assert a little more expressive, like in (let [x "foo"] (assert (number? x)))
11:14	borkdude	now it prints Assert failed: (number? x)
11:14	clgv	ah right I vaguely remembered a dynamic binding
11:15	borkdude	I want to see: "foo is not a number"
11:15	clgv	,(doc assert)
11:15	clojurebot	"([x] [x message]); Evaluates expr and throws an exception if it does not evaluate to logical true."
11:15	clgv	,(assert (number? 'x) "foo is not a number")
11:15	clojurebot	#<AssertionError java.lang.AssertionError: Assert failed: foo is not a number\n(number? (quote x))>
11:16	justin_smith	,(binding [assert false] (assert false) true)
11:16	clojurebot	#<AssertionError java.lang.AssertionError: Assert failed: false>
11:16	justin_smith	hmm
11:17	justin_smith	,(set! assert false)
11:17	clojurebot	#<IllegalStateException java.lang.IllegalStateException: Can't change/establish root binding of: assert with set>
11:17	justin_smith	ahh, can't do it on clojurebot, but that is how it is done (works in my repl)
11:18	clgv	justin_smith: yeah that wont work.
11:18	clgv	justin_smith: it must be set befor your actual files are compiled
11:18	justin_smith	ahh, of course
11:18	justin_smith	so yeah, set it in project.clj
11:18	clgv	justin_smith: so :global-vars or java commandline are the only places where it has an effect
11:19	justin_smith	well, setting it will effect things compiled after that point
11:19	justin_smith	so you could turn off assertions before requiring other code... but that seems messy
11:19	clgv	yeah right, without AOT that is tricky
11:19	borkdude	clgv yeah, but those are not used by default in defn
11:20	clgv	borkdude: ah ok you meant for _pre/:post ...
11:20	borkdude	clgv yeah
11:21	borkdude	clgv I guess this is what Schema is for
11:21	clgv	borkdude: maybe contracts are the better choice: https://github.com/clojure/core.contracts
11:21	clgv	ah well that schema lib probably as well...
11:24	borkdude	clgv or core.typed
11:25	borkdude	clgv or Haskell
11:25	borkdude	:P
11:41	Fender	ok, so I have this function (fn transform [args]) and I want to return the sexpr represenation of function call like, e.g., (let [targs (map transform args)] (cons f (cons some-param targs))). Now if f is ternary and has >=3 args, I need to call something like (reduce #(f some-param %1 %2) (first targs) (rest targs)). I tried some (list reduce (list fn '[x1 x2] (f some-param x1 x2)) (first targs) (rest targs)) but that doesnt work some r
11:42	Fender	forgot some quotes
11:42	Fender	thing is not that my code doesnt compile, it's that it returns (first args)
11:45	Fender	even (list #'reduce #'println (first targs) (rest targs)) doesnt print anything
11:45	Fender	but (cons f (cons some-param targs)) does
11:47	borkdude	I thought to myself: which idiot calls a function like (#'function ...)
11:47	borkdude	but I did it myself because the function was prive
11:47	borkdude	private ;)
11:48	borkdude	unit tests
11:48	Fender	well, you also might need it in web handlers
11:48	Fender	but that's something else
11:49	justin_smith	Fender: why would (list #'reduce #'println (first targs) (rest targs)) print anything? is this a macro?
11:50	Fender	its just for testing
11:50	Fender	I want to substitute println by something else
11:52	justin_smith	but putting println in a list is not going to print anything, and if you thought it would you should probably back up and read some basic clojure intro
11:53	clgv	,(reduce #(do (println %2) %1) nil (range 5))
11:53	clojurebot	0\n1\n2\n3\n4\n
11:53	borkdude	Fender I know
11:53	justin_smith	clgv: but that's not what he was doing - he was literally putting #'println in a list
11:53	clgv	though a `doseq` would be the right tools here ;)
11:54	clgv	justin_smith: I just showed him how his goal of printing via reduce would work
11:54	justin_smith	oh, I had no idea what any of that was supposed to do
11:55	Fender	well, I was talking more like (eval (list reduce (list 'fn ...) )
11:56	justin_smith	eval is bad. Always look for a way not to use eval.
11:56	Fender	as I said, "I want to return the sexpr represenation of function call"
11:56	grandy___	anyone know the best way using secretary to make routes show up in the location when they are navigated to?
11:56	Fender	thanks justin, I know that
11:58	clgv	you want to retrieve the sexpr that defines a function?
11:58	Fender	eaxactly
11:58	Fender	and I got it
11:58	clgv	well, no idea what your problem is then..
11:58	Fender	the targs had to be made a list by (cons list ...) again
11:59	Fender	imagine you get a function description (sexpr) via eMail and you want to offer this function via a web service to the subscriber
12:00	Fender	sexpr is basically just the mathematic subset of clojure
12:00	justin_smith	Fender: so something like serializable-fn
12:00	justin_smith	https://github.com/technomancy/serializable-fn
12:01	Fender	actually the opposite
12:01	clgv	justin_smith: I thought he said he managed that already?
12:01	Fender	I get a function description
12:01	Fender	but thanks anway
12:02	danneu	has anyone deployed an uberjar straight to heroku, bypassing heroku's own build process?
12:03	clgv	to get a compiled function from an s-expr represented string you can just used read-string and eval
12:04	Fender	well, as said, I had to transform the arguments beforehand
12:04	Fender	and the function actually was also transformed
12:05	justin_smith	so you are hand rolling a substitute for macros
12:05	Fender	kind of
12:05	Fender	I think thats a good description
12:07	technomancy	danneu: you could do that with the new build api https://blog.heroku.com/archives/2014/5/21/introducing_programmatic_builds_on_heroku
12:07	technomancy	haven't tried it myself
12:08	danneu	technomancy: thanks
12:08	technomancy	danneu: sorry, this link is better https://blog.heroku.com/archives/2013/12/20/programmatically_release_code_to_heroku_using_the_platform_api
12:16	mbac	(.. java.net.InetAddress getLocalHost getHostName)
12:16	mbac	what's ..?
12:16	ToxicFrog	Repeated .
12:17	ToxicFrog	eqv to java.net.InetAddress.getLocalHost().getHostName()
12:17	nullptr	http://clojure.org/java_interop#Java Interop-The Dot special form-(.. instance-expr member+)
12:17	mbac	whoa
12:18	clgv	,(.. java.net.InetAddress getLocalHost getHostName)
12:18	clojurebot	"localhost"
12:18	clgv	hehe
12:19	mbac	cute
12:24	TimMc	It expands to (-> java.net.InetAddress (.getLocalHost) (.getHostName))
12:25	TimMc	err... almost
12:26	TimMc	I guess .. has some special logic to turn that first call into a static method call.
12:34	clgv	,(macroexpand-1 '(.. java.net.InetAddress getLocalHost getHostName))
12:34	clojurebot	(.. (. java.net.InetAddress getLocalHost) getHostName)
12:34	danneu	i have to stop and think about it every time i see '..' and '.'
12:34	clgv	,(. Long (parseLong "42"))
12:34	clojurebot	42
12:35	clgv	as it seems there is no special logic needed for static calls
12:36	technomancy	. isn't meant for direct usage
12:36	technomancy	and .. is pretty archaic too
12:39	borkdude	integer? returns true for all longs?
12:39	Bronsa	borkdude: the docstring never mentions any concrete java class
12:39	borkdude	k, I'm looking at the source now
12:40	borkdude	Bronsa what do you mean, never?
12:40	dbasch	borkdude: yes
12:40	Bronsa	integer doesn't mean Integer
12:40	virmundi	Hello. I'm looking for naming guidance on methods and logging. My understanding is that everything that has a side-effect should have an "!" at the end. Logging is a side-effect. Therefore, should any methods that have logging end in "!"?
12:41	dbasch	virmundi: no, side effects usually mean changing state
12:41	dbasch	log is similar to print
12:42	virmundi	Ok. Thanks.
12:43	borkdude	Bronsa k
12:49	TimMc	So it's really . that has the smarts.
12:50	Nova_	Thanks you, but if you make an account with that url you will have 10 usd for start... https://www.digitalocean.com/?refcode=57f20058a282
12:52	gfredericks	Any guesses why adding lein-cljsbuild repl-listen code to the om tutorial gives me a repl that hangs on eval?
13:05	mdeboard	gfredericks: It's because you don't have a browser window open to the page I bet
13:05	mdeboard	the right port etc
13:06	mdeboard	it's just waiting for a browser to eval the code in, I think.
13:13	michaelmeixner	newbie has a short question
13:14	michaelmeixner	I want to calculate the deltas between the elements of a vector
13:14	michaelmeixner	say [2 3 5 8]
13:14	michaelmeixner	I found I can do :
13:15	michaelmeixner	(partition 2 1 [2 3 5 8])
13:15	ben_m	(map - coll (rest coll))
13:15	michaelmeixner	ah ...
13:16	ben_m	Change - to a lambda if you want absolute deltas of course :)
13:16	michaelmeixner	great, thanks - I knew there had to be a simple solution
13:17	michaelmeixner	thanks again
13:17	justin_smith	michaelmeixner: there is also (map #(apply - %) (partition 2 1 coll))
13:17	ben_m	michaelmeixner: You're welcome
13:27	literary	help
13:27	ben_m	911?
13:28	lavokad	:D
13:28	literary	Caused by: java.lang.IllegalArgumentException: No implementation of method: :make-reader of protocol: #'clojure.java.io/IOFactory found for class: nil
13:28	literary	wth
13:28	literary	java.lang.ExceptionInInitializerError
13:29	noonian	sounds like some sort of null pointer exception
13:29	noonian	you are passing nil to something where you think you have a non-nil value
13:29	literary	its on line 1 of a file
13:29	literary	the (ns) line
13:36	literary	it fails consistently, and did not fail on friday.
13:36	literary	i have no understanding of why it fails.
13:36	justin_smith	can you share a paste of the ns declaration?
13:37	noonian	literary: if you post your ns form on refheap, pastebin, or as a gist people here will be in a better position to help you
13:42	Bronsa	literary: are you using core.typed?
13:43	literary	no
13:43	mdeboard	hm
13:43	Bronsa	literary: you need to post the source that's causing that exception anyway, we can't help you only with that exception
13:44	mdeboard	Can someone help me understand why this happens
13:44	mdeboard	&(apply Math/abs [-1 -2 -3])
13:44	lazybot	java.lang.RuntimeException: Unable to find static field: abs in class java.lang.Math
13:44	Bronsa	mdeboard: methods aren't first class objects like functions
13:44	justin_smith	mdeboard: methods are not first class
13:44	mdeboard	I see
13:44	ben_m	&(apply #(Math/abs %) [-1 -2 -3])
13:44	lazybot	clojure.lang.ArityException: Wrong number of args (3) passed to: sandbox5671$eval12864$fn
13:45	ben_m	Well whatever but that.
13:45	Bronsa	mdeboard: there's really no good wayt to use apply with static methods
13:45	mdeboard	well yeah but I got that too, and don't understand
13:45	mdeboard	Bronsa: I see, ok
13:45	mdeboard	you can't use map either right
13:45	mdeboard	or reduce
13:45	mdeboard	(no reduce implies no map, you're right
13:45	mdeboard	)
13:45	Bronsa	mdeboard: well you can, you just have to wrap the method call in an anonymous function
13:46	justin_smith	mdeboard: only first class Objects can be arguments to functions
13:47	mdeboard	Oh right
13:47	mdeboard	&(apply #(Math/abs %) [-1])
13:47	lazybot	⇒ 1
13:47	literary	Bronsa, noonian, https://gist.github.com/anonymous/4f4463805ba92ca1036b
13:47	mdeboard	understood
13:48	mdeboard	I got nerd-sniped
13:48	Bronsa	mdeboard: what I meant by "you can't use apply for methods" is that usually you use apply when you don't know the arity of the function you're invoking -- you have to know the arity of the method you're invoking
13:49	TimMc	Don't tell me what I have to do!
13:49	mdeboard	&(let [coll [2 3 5 8]] (map (comp #(Math/abs %) -) coll (rest coll)))
13:49	lazybot	⇒ (1 2 3)
13:50	mdeboard	ben_m nerd-sniped me
13:50	mdeboard	with the absolute value thing
13:50	ben_m	I knew why it didn't work but I didn't immediately know how to fix it.
13:50	noonian	literary: do you require any namespaces in that file that you wrote? if so the bug is probably in one of those files and because the ns didn't compile you can't require it in that one
13:51	literary	yes
13:52	TimMc	&"you there?"
13:52	lazybot	⇒ "you there?"
13:52	TimMc	Bronsa: ##(apply #(clojure.lang.Reflector/invokeStaticMethodVariadic "java.lang.Math" "abs" (object-array %&)) [-1])
13:52	lazybot	java.lang.SecurityException: You tripped the alarm! class clojure.lang.Reflector is bad!
13:52	grandy___	quick question: when working with reagent and secretary, if I call (secretary/dispatch! "/some-route") it loads the handler, but the url still shows "/". If I hook into google history and watch for navigation events and call secretary/dispatch! when such an event occurs, then when I call (secretary/dispatch! ... ) the handler gets called twice... any
13:52	grandy___	ideas?
13:52	TimMc	oy
13:52	noonian	literary: i would try, from the repl, requiring each of the other namespaces you wrote manually until one fails and then look closer at that one
13:53	literary	thank
13:53	TimMc	,(apply #(clojure.lang.Reflector/invokeStaticMethodVariadic "java.lang.Math" "abs" (object-array %&)) [-1]) ;; let's try the other parent
13:53	clojurebot	1
13:53	literary	lein repl fails for me
13:53	literary	Exception in thread "main" java.lang.ExceptionInInitializerError
13:53	literary	(inc TimMc)
13:53	lazybot	⇒ 72
13:54	noonian	literary: if you have a :main key in your project.clj just comment that out for now
13:54	noonian	literary: then your repl should start up in the 'user namespace
13:54	Bronsa	TimMc: c.l.Reflector is cheating
13:54	literary	does
13:54	TimMc	literary: I wonder how many of my karma points are for awful ideas I give to people.
13:54	TimMc	Bronsa: :-D
13:55	literary	TimMc: dont beat yourself up over it everyones just doin their best you know what they say be more kind than necessary to everyone you meat for they are fighting a hidden battle that you know nothing about
13:57	literary	found it
13:57	literary	(slurp nil)
13:57	literary	clojure.java.io/resource stopped working in tests at some point
13:57	noonian	literary: nice!
13:57	literary	not that it ever was executed during tests,
13:57	literary	but now it no longer even compiles during tests
13:57	jba-123	what's the recommended way to have multiple core-async listener ?
13:57	literary	oh wait its not in a funciton its in a def
13:57	literary	thanks you noon ian
13:58	noonian	no problem
13:58	literary	i really think this is the worst error message
13:58	literary	i think even perl is more readable
13:58	literary	and nobody can read perl not even perl parsers
14:01	bbloom	seems like puredanger is going around bumping tickets to 1.8
14:02	bbloom	i guess that means a 1.7 release is eminent
14:03	Bronsa	bbloom: yeah, I'm a bit disappointed that critical bugs are getting postponed once again though :/
14:04	bbloom	Bronsa: i'm only disappointed b/c i know how slow the release cycle is. i understand the desire to ship transducers though
14:04	bbloom	maybe 1.8 will be a quick follow up to 1.7, we'll see
14:04	Bronsa	I hope that too, but I won't bet on it
14:05	bbloom	me neither
14:05	hiredman	it never is
14:05	Bronsa	I'm a bit tired of having to rework all my patches all the times because they break with the last master
14:06	bbloom	yeah, that's the biggest reason i don't contribute patches as often as i would (all jokes about jira aside) -- contributing patches creates reoccurring work for me
14:06	gfredericks	mdeboard: I think I had it open; doesn't it not show the repl prompt at all until a browser connects?
14:09	mdeboard	gfredericks: mmm maybe!
14:09	Bronsa	bbloom: I only keep contributing patches because I know that a ticket without patch will rot forever
14:09	bbloom	yup
14:09	hiredman	watching http://dev.clojure.org/jira/browse/CLJ-1297 comments roll through my inbox every morning always makes me shake my head
14:11	hiredman	I guess today wasn't a comment, just alex bumping it
14:18	m1dnight_	So _tried_ reading the paper on Actors by Carl Hewitt but it just does not make sense to me..
14:29	danneu	if you start a go-loop in an Om component's IWillMount that spins forever, i suppose you need to poison the go-loop in IWillUnmount or it'll keep going even after it's been removed from the dom, right?
14:31	nullptr	danneu: that's my understanding -- it will be "waiting forever" in that case
14:31	nullptr	you can just close the channel in IWillUnmount and abort the go-loop
14:32	nullptr	i haven't confirmed that though
14:32	turbofail	m1dnight_: haven't read it myself, but from what i've heard you're in good company there
14:33	danneu	it's just (go-loop [] (<! (timeout 1000)) ... (recur)). i suppose i would (let [[ch v] (alts! [(<! (timeout 1000)) poison-ch]) when (not= ch poison-ch) recur.
14:35	nullptr	e.g. https://github.com/swannodette/om-sync/blob/master/src/om_sync/core.cljs#L121
14:38	danneu	nullptr: thanks, will copy the master
14:41	m1dnight_	turbofail: It's really messy. Imagine a paper written on a typewriter, pulled through OCR 10 times. It's something like that :p
14:41	m1dnight_	There is a "summary" by Gul Agha and Rasjesj Karmani which is very readable and to the point.
15:09	danneu	i want to create a stateful Om component for every user in the list that follows them as they are shifted around. however, my stateful ticker-components don't work how i think they would: https://www.refheap.com/91285
15:12	nullptr	you need to add a key so react knows the canonical identity -- you probably have a warning about that in your js console
15:12	nullptr	http://facebook.github.io/react/docs/multiple-components.html#dynamic-children
15:19	danneu	nullptr: thanks for the help. got it working
15:19	danneu	(got no console err, though)
15:20	borkdude	cfleming dunno what this is https://www.dropbox.com/s/obicqrmq8ujc741/Screenshot%202014-10-06%2021.18.45.png?dl=0
15:20	borkdude	cfleming cursive still seems to work ;)
15:23	liflash	hi everyone
15:26	liflash	i'm using om-sync and the ring middleware for sending edn parameters from a client to the server. the sent request is correct and contains everything needed, but on ther server side the parameter never arrives. That is the edn-params in the request map is always nil. any ideas?
15:27	danneu	nullptr: my goal here was to make a jquery.timeago.js-like component. (auto-updating distance-in-words, e.g. "2 min ago" -> "3 min ago"). gist: https://gist.github.com/danneu/10280fe5e4079634917c
15:27	nullptr	liflash: you're wrapping your routes with wrap-edn-params?
15:27	liflash	exactly
15:30	danneu	(the gist works now)
15:30	liflash	do you need some more info to think of possibilities?
15:31	nullptr	danneu: cool -- you might also be interested in: https://github.com/Prismatic/om-tools#mixin-tools
15:31	nullptr	liflash: what's your route definition look like?
15:31	danneu	nullptr: thanks
15:33	liflash	(defroutes some-routes (POST "/timeline/updaterank" [edn-params :as para]
15:33	liflash	(println "update-rank request parameter map: " edn-params "\npara: " para)))
15:33	liflash
15:34	nullptr	i have a working project where it's defined as:
15:34	nullptr	(POST "/rsvp" {edn-params :edn-params} (rsvp edn-params))
15:35	liflash	yeah, i had look into it and on the github site compojure explains that there are different ways of destructuring. they introduced their own style for simplicity
15:35	liflash
15:35	liflash	but good to know it works for you
15:36	nullptr	if the mime types are right and the middleware is installed properly not sure where else it'd go awry
15:36	nullptr	minimal: (def app (-> routes wrap-edn-params))
15:36	liflash	(wrap-edn-params routes) should work, too, right?
15:43	d0ky	hello is that implementation of RBtree http://daly.axiom-developer.org/clojure.pdf#section.2.4 suitable for program like videostore to make custom data structure to store there items ?
15:47	danneu	liflash: when in doubt, i drop in some noisy middleware and compare it to what i'm seeing in in the Network tab of my browser dev tools https://gist.github.com/danneu/ac3a99ac8eb0c0f4ca58
15:47	justin_smith	d0ky: I'd assume you want persistence, which probably means a real database of some sort
15:48	liflash	danneu: thanks, will have a look
15:49	d0ky	justin_smith: not really it is to school and i has to be in java and i want to practice functional approch ... and rich hickey is good at it so that's why i want to do that way to learn something new
15:53	liflash	danneu: any idea why pprint is unknown?....
15:54	noonian	liflash: you need (:require [clojure.pprint :refer [pprint]])
15:55	borkdude	how does one combine core.typed with prismatic/schema? when I use a s/defn core.typed gets screwed
15:55	liflash	danneu: oops, thought it was available by default, thanks
15:57	borkdude	I must say I like both approaches: core.typed for static checks, schema for run time checks
15:59	mr_rm	is this the right place to ask a question about the library "Liberator"?
16:00	mr_rm	don't see a dedicated irc channel
16:00	borkdude	mr_rm sure, ask
16:01	mr_rm	i have this code: http://pastebin.com/McMHm0md when i call post with curl, i get the "called post" message. unfortunate, i get the same from my browser. i don't understand why GET from the browser goes to the post! function
16:02	liflash	danneu: nullptr : just tried the debug middleware and the request seems to be empty on arrival already... but the network infos from the browser request tools tell me the request was sent with the correct data. this looks like something totally stupid
16:03	liflash	danneu: nullptr on my side, of course ;)
16:04	mr_rm	borkdude: sorry, i should have posted the defresource for user too: http://pastebin.com/2TjNLfF2
16:04	jlongster	I was looking at how core.async handles transducers that produces more values than it takes in (mapcat), and saw that a FixedBuffer will actually resize if that happens. so the size is not fixed. is that not a problem usually?
16:04	jlongster	dnolen_: ^
16:04	danneu	liflash: can you substantiate that the request has header "Content-Type": "application/edn"?
16:05	ale`	Hi, I'm playing with Clojure-clr, specifically I am trying to eval clojure code from a c# console program. This is the sample code: https://gist.github.com/3e83f8f413f570b47339 . I get a NullReferenceException when I eval the import statement. What am I doing wrong?
16:05	borkdude	mr_rm aren't the :allowed-methods etc supposed to be in the liberator resource rather than in the compojure route?
16:07	borkdude	mr_rm if you can just post your whole namespace it's easier to see
16:07	borkdude	mr_rm because namespace definitions matter
16:07	dnolen_	jlongster: a problem how?
16:08	danneu	liflash: what does (:body request) look like? all wrap-edn-params does is, if content-type is some form of application/edn, then (edn/reader (:body req)) and (assoc req :edn-params result-of-that).
16:09	jlongster	dnolen_: you assume a certain buffer size which implies certain blocking behavior. but I get the sense you don't write go blocks that depend that specifically on the details of non-blocking/blocking
16:09	jlongster	I need to write more code with buffers
16:09	mr_rm	borkdude: right, i understand. i think you're right about putting :allowed-methods in the resource. i'll try that. in the meantime: http://pastebin.com/p2hQSSgq
16:10	borkdude	mr_rm also :handle-ok etc
16:10	borkdude	mr_rm you should call the resource from liberator and then the resource decides via the liberator decision tree what to return
16:10	liflash	danneu: in fact i can't. regarding the output of your debugging lines, the request before the handler has content-type nil
16:10	borkdude	mr_rm call the resource from the compojure route I mean
16:11	dnolen_	jlongster: right this is why it's preferred that an api receive a pre-allocated channel
16:12	dnolen_	jlongster: buffering is a property of channels not go blocks themselves
16:12	liflash	danneu: ok, i think there must be something wrong with the authorization middleware. a friend of mine wrote it using friend. maybe he got something wrong with the routing
16:13	mr_rm	borkdude: gotcha. yes i see that i skipped the resource entirely in the process. that helps
16:14	jlongster	dnolen_: yeah. right now we throw an error in `add` on a FixedBuffer if it is full, and I just noticed that that's different
16:14	jlongster	it feels weird to resize the buffer automatically, but if the user shouldn't care about it, cool
16:14	liflash	danneu: thanks a lot for your help. will have a look at it on my own for now
16:21	mr_rm	borkdude: yeah, that works when i put it all inside the one resource. i was suffering a case of mild retardation: http://pastebin.com/g7b56yWS
16:21	mr_rm	borkdude: thanks again
16:24	mr_rm	borkdude: i had the (do (println...)) in there just to see something quickly but i can see it's doing the right thing now for both GET and POST. that certainly cleared up my confusion re putting those keywords in the resource, not the route
16:25	mr_rm	borkdude: if you don't mind another question, is Liberator still viewed as a good library in this space. it looks perfectly fine to me but i'm only just getting started with web dev in clojure and don't know the ecosystem very well yet
16:26	mr_rm	borkdude: s/space\./space\?/
16:27	kenrestivo	are there any gotchas i should look out for when backing a core.async channel with an inputstream?
16:29	hiredman	what does backing mean?
16:31	ppppaul	anyone here use lighttable ?
16:31	hiredman	in any case you'll want to use a ReadableByteChannel and bytebuffers, not an InputStream
16:37	borkdude	mr_rm yes, I view liberator as a good library for creating REST services
16:39	ppppaul	liberator has a little bit of a learning curve. worth it if you want to handle many types of status codes in a more declarative way
16:40	borkdude	mr_rm take a look at the decision tree of liberator, that's really the main idea of it
16:42	perplexa	hello. anybody here using cursive? i just imported a leiningen project and it says "xyz cannot be resolved" for everything. all clojure core functions included. is there anything i'm missing?
16:42	borkdude	perplexa I'm using cursive, but I didn't use "import"
16:43	borkdude	perplexa I just open the project.clj
16:43	borkdude	perplexa ask cfleming
16:44	dbasch	http://diegobasch.com/random-partition-of-a-sequence justin_smith gfredericks
16:45	perplexa	borkdude: how do you just open the project.clj? :P
16:45	borkdude	perplexa File -> Open or something
16:45	liflash	danneu: still there?
16:45	perplexa	borkdude: it doesn't really create a project from that, though
16:46	hiredman	perplexa: likely your repl has ns set to a namespace that doesn't have anything refered in to it
16:46	borkdude	perplexa no, I create projects with leiningen from the shell
16:46	hiredman	perplexa: you should be able to call core functions if you fully qualify
16:46	hiredman	(clojure.core/+ 1 2)
16:46	gfredericks	dbasch: woohoo I'm internet famous!
16:46	perplexa	borkdude: me too ;P
16:46	hiredman	how or why your repl is in that state, I dunno
16:47	perplexa	mh
16:47	borkdude	perplexa ah, well, then you're good to go
16:47	gfredericks	dbasch: (random-partition (range)) is a cool idea I wouldn't have thought of
16:47	liflash	danneu: just saw that content-type isn't empty. don't know what happened the first time. the (:body req) is #<HttpInput org.eclipse.jetty.server.HttpInput@155b539>, how can i see what's in there?
16:47	dbasch	gfredericks: you should expect 0.2 new twitter followers from my post :P
16:50	gfredericks	dbasch: hey there the are right now
16:50	perplexa	borkdude: yeah, was using vim + leiningen's repl so far. but wanted to give cursive a shot
16:55	dogonthehorizon	Greetings folks. I have a nested Clojure collection that I am attempting to convert to its Java counterpart using clojure.walk/postwalk. However, I can't figure out why I'm getting an NPE when I traverse the first collection type. Would anyone be able to explain this? Thanks! Here's a conensed snippet of the problem: https://gist.github.com/dogonthehorizon/41f65925f595180f096e
16:56	amalloy	dogonthehorizon: clj-type->java-type returns nil for anything but a map or vector
16:56	borkdude	perplexa I've been working with it for a few days, and I like it so far
16:56	amalloy	but like...just don't write this function at all. clojure's lists implement j.u.List, etc
16:57	dogonthehorizon	amalloy: d'oh, missed that one. But what do you mean I shouldn't write the function? How would I go about translating the types for use in Java?
16:57	amalloy	just don't. give them the clojure types
16:58	dogonthehorizon	Wouldn't that require me to import clojure.lang and friends in my Java code?
16:58	amalloy	no
16:58	amalloy	the point is that an IPersistentVector is a j.u.List, and it's Iterable, and all that good stuff
16:59	amalloy	so you can iterate over it with like: for (Long l : coll) ...
16:59	justin_smith	dbasch: re: the blog post, very cool
16:59	hiredman	I dunno
17:00	hiredman	will javac let you do that without generics?
17:00	liflash	how can i find out what's in the :body #<HttpInput org.eclipse.jetty.server.HttpInput@155b539> of a request?
17:00	amalloy	hiredman: just lie about the types: List<Map<String, Integer>> loms = f.invoke(x)
17:01	hiredman	amalloy: ah, sure
17:01	dogonthehorizon	amalloy: ...ah. Well now I feel silly for going through all this work, heh. Thanks for walking me through that! :)
17:03	borkdude	dogonthehorizon there's also an API for calling clojure functions from java: https://github.com/clojure/clojure/blob/master/src/jvm/clojure/java/api/Clojure.java
17:04	noonian	liflash: according to the docs that is a subclass of java.io.InputStream so you can probably just use slurp to read it
17:05	dbasch	justin_smith: thanks
17:05	liflash	noonian: thanks, didn't know where to look at
17:05	dbasch	justin_smith: btw, I ended up bringing that geohash code down to the same speed as the java version https://www.refheap.com/91288
17:05	noonian	liflash: np
17:06	dbasch	thanks to Bronsa who pointed out that bit-flip and bit-test are not inlined
17:06	dogonthehorizon	borkdude: Yeah, I looked at that api a while back but calling Clojure like this feels less fluid. I've chosen the gen-class/aot route to wrap the logic in my Clojure project, but the final piece of the puzzle was getting the return statements to line up with the types I was expecting in Java.
17:06	clojurebot	No entiendo
17:06	borkdude	dogonthehorizon makes sense
17:11	liflash	is #<HttpInput org.eclipse.jetty.server.HttpInput@155b539> the expected :body when using http-kit?
17:12	noonian	liflash: are you using ring? you should get a map with a :body and :status key if so
17:12	liflash	i would expect to get the body i send from the client, like for example a map
17:13	liflash	yes, i use ring
17:14	noonian	liflash: try (println (slurp (:body request)))
17:14	liflash	this returns the expected body
17:16	justin_smith	liflash: the reason you get a HttpInput is that you may be able to close the stream after reading a few bytes - the most flexible option is to handle you an abstraction for the input from the client, and let you read as much or as little as you want
17:18	liflash	i see
17:18	brehaut	$seen technomancy
17:18	lazybot	technomancy was last seen talking on #clojure 4 hours and 41 minutes ago.
17:19	liflash	my core problem is that wrap-edn-params seems to be able to extract the edn from that inputstream
17:19	rurumate	how to define riemann zeta function in clojure?
17:20	rurumate	mathematica has it built in it seems
17:20	liflash	seems not to be, sorry
17:22	hiredman	liflash: are you setting the content type?
17:23	liflash	i'm using om and the content-type is set to application/edn
17:24	hiredman	what edn params middleware are you using?
17:24	liflash	compojure
17:24	liflash	no, sorry
17:24	liflash	ring
17:25	hiredman	liflash: I don't think ring has such a thing
17:25	hiredman	https://github.com/ring-clojure/ring/tree/master/ring-core/src/ring/middleware
17:25	liflash	i required [ring.middleware.edn :refer [wrap-edn-params]]
17:26	hiredman	liflash: ok, but where did ring.middleware.edn come from?
17:27	justin_smith	maybe this one ? https://github.com/tailrecursion/ring-edn/tree/master/src/ring/middleware
17:27	liflash	oh, i see what u mean. i think it comes from [fogus/ring-edn "0.2.0"]
17:28	liflash	i'm working with a friend of mine, he added it
17:28	liflash	and he says all this already worked
17:28	liflash	don't know what the problem is
17:28	liflash	the content type is correct, but the resulting map only contains :edn-params nil
17:29	hiredman	sounds like the inputstream is empty or contains nil
17:29	hiredman	(or you are printing out the contents of the inputstream before the middleware can read it)
17:30	justin_smith	yeah, input streams are stateful, so be careful of emptying it prematurely
17:32	justin_smith	dbasch: cool - at least to me the clojure version is nicer than the java. Pity it took more work to make it perform.
17:33	dbasch	in fact with the latest feedback from amalloy it’s now faster than the java version https://www.refheap.com/91289
17:34	liflash	hiredman: hmmm... currently looks like a mess and i don't know where to start. will have deeper look first. thanks for your hints
17:40	turbofail	huh. why aren't bit-test and bit-flip inlined?
17:41	turbofail	just an oversight?
17:41	dbasch	turbofail: they are not
17:41	hiredman	likely
17:41	hiredman	(which is why a machine shoud be generating all this)
17:41	dbasch	oh, why, yeah most likely an oversight
17:41	amalloy	i'd guess it's because there's no single jvm bytecode for them
17:42	amalloy	the others are inlined so that they can be removed entirely and replaced with a bytecode instruction, via intrinsics
17:42	amalloy	whereas inlining this one doesn't buy you anything more than letting hotspot inline it
17:42	Bronsa	amalloy: them being not inlined prevents the unboxed arities to be used though
17:42	turbofail	yeah, their function definitions don't do any type hinting
17:43	amalloy	ah, yes indeed, since there are primitive versions that definitely should be inlined
17:46	hiredman	it should all be machine generated
17:50	akurilin	Has anybody here succeeded with disabling connection pooling done by Korma?
17:50	akurilin	Trying to figure out if I'll have to fork the lib to do it
17:52	akurilin	Hm I guess there's :make-pool? in there
17:54	gfredericks	huh. I've never noticed a lib with no dependencies before
17:54	gfredericks	only lists clojure under :dev
17:55	gfredericks	(test.check)
17:57	amalloy	gfredericks: that seems like a decent idea, really
18:02	TimMc	I only just introduced a dependency on cloure.set into org.timmc/handy, which surprised me.
18:03	TimMc	*clojure, why does my typing suck so much these days
18:04	technomancy	for once we can't blame nil
18:12	vIkSiT	hello all
18:12	vIkSiT	what's the easiest way to add a snapshot build of a library using lein?
18:12	vIkSiT	eg, om 0.7.3 is stable, but the github master branch is on 0.7.4 snapshot
18:13	nullptr	you can just pull the code and run: lein install
18:13	vIkSiT	what can I do to add the latter to my project.clj?
18:13	vIkSiT	nullptr, ah - and then it get's installed as a dep into .m2?
18:13	nullptr	yup
18:13	technomancy	vIkSiT: it depends on whether the snapshots are published
18:13	vIkSiT	(and project.clj will pull it once the entry is added?)
18:13	vIkSiT	technomancy, right, the snapshots aren't published in this case
18:13	technomancy	if they are, it will just work
18:13	em-dash	I’m sure this is dead simple: what kind of strategy should I use to find a map (which contains a specific key) within a vector of maps?
18:13	technomancy	yeah, in that case manual lein install
18:13	vIkSiT	cool, ty
18:14	justin_smith	em-dash: are you looking for it once, or looking repeatedly?
18:14	em-dash	I expect it to appear once in the vector
18:14	justin_smith	how often do you look it up?
18:15	justin_smith	for finding it once (first (filter ...)) if repeatedly, (group-by :your-key vec-of-maps)
18:15	em-dash	oh, I want to extract it and build a map with the value I find (I’m parsing horribly formatted XML)
18:15	vIkSiT	has anyone here used clojurescripts nativestore btw?
18:15	em-dash	justin_smith: thank you! that’s exactly the nudge I needed :)
18:16	vIkSiT	and another question - when using luminus, if I connect to the lein REPL using cider, adding a new route doesn't reflect in the running program - need to manually quit the repl and re "lein repl"
18:16	justin_smith	em-dash: for example if you are finding many items by the same key, group-by is a huge win
18:17	vIkSiT	any ideas on why repl/running program state wouldn't get updated through cider, C-c C-k? or even C-x C-e?
18:17	em-dash	justin_smith: I’m dealing with ill-formatted XML. once I get the data into a sane shape, group-by will be much more applicable
18:17	em-dash	justin_smith: thanks again :)
18:18	justin_smith	vIkSiT: if some service like ring was initialized by having a function passed in, just chaning the def of the function won't change what the server runs
18:18	justin_smith	for example
18:18	justin_smith	also look out for things that have defonce semantics
18:19	vIkSiT	ah
18:19	justin_smith	for example defmulti
18:19	vIkSiT	it's basically a defroute, yes - using ring
18:19	justin_smith	pass #'handler to the server process rather than handler
18:19	justin_smith	ring will dereference the var instead of using the value of the var
18:19	justin_smith	*do a dereference of the var for each request, that is
18:23	vIkSiT	justin_smith, not sure I understood that last part
18:23	vIkSiT	how do you mean pass the deferenced handler to the server?
18:24	justin_smith	I mean the server derferences on each request
18:24	dbasch	whenever I see defonce I think of beyonce
18:24	vIkSiT	I just go to the (deroute my-app ... (GET "/route" [] (my-handler)) and C-x C-e
18:24	justin_smith	rather than getting the immutible fn value and just using that
18:24	justin_smith	right, and that changes a var
18:24	vIkSiT	right
18:24	justin_smith	it does not alter the fn that you passed to the server
18:24	seangrove	dbasch: But isn't it true that you're just generally thinking of beyonce?
18:24	vIkSiT	ah
18:24	justin_smith	the server is still using the old fn
18:24	vIkSiT	well.
18:24	dbasch	(beyonce put! “a ring on it”)
18:24	justin_smith	if you pass in a var, it can deref for each request
18:25	vIkSiT	C-x C-k should do the right thing though?
18:25	dbasch	seangrove: no, just this once
18:25	seangrove	Damn, outclassed
18:26	justin_smith	vIkSiT: how can it if the ring process did not receive a var?
18:26	justin_smith	if it does not get a var, and only an fn, it has no way to see a new value
18:26	justin_smith	unless you kill and restart the server on every ns refresh
18:29	grandy___	can someone help me with a potentially dumb conceptual question about secretary for cljs ? Trying to figure out how to make the URL in the browser show the proper "route" after secretary/dispatch! .. tried hooking in google history but then the navigation event triggers the route a second time on the initial page load
18:29	vIkSiT	justin_smith, I think I see your point
18:29	vIkSiT	trying to wrap my head around it..
18:29	grandy___	using secretary + reagent on the client side and compojure+yesql on the server side
18:30	justin_smith	vIkSiT: if the server process was using your handler function directly, it would see the update (as long as it had not been inlined)
18:31	justin_smith	vIkSiT: but when it gets a function as an argument, it only gets the fn
18:31	vIkSiT	ah
18:31	justin_smith	vIkSiT: when you change a defn, you don't mutate the fn it referred to - that is immutible and still referred to by the server process. The only way the server (which never saw the name of your function) to see an update is to get the var that gets rebound
18:31	vIkSiT	it gets the defintion of function f at time t1.
18:32	justin_smith	right
18:32	vIkSiT	and then at time t2, i add a new route
18:32	vIkSiT	now, i cx ce the function
18:32	justin_smith	and the fn does not change - the var just points to a different fn now
18:32	vIkSiT	the function itself uptakes the value at t2, ie, if I were to use it now, it would work fine
18:32	vIkSiT	but ring still has the pointer of fn at time t1?
18:32	cfleming	borkdude: That's a weird screenshot - can you send me your log at cursive@cursiveclojure.com? Help->Show log in Finder/Explorer/whatever it is on Linux
18:33	vIkSiT	so I need some way to update ring's pointer from fn at time t1 to t2
18:33	cfleming	perplexa: Did you get that cursive problem sorted out?
18:33	vIkSiT	justin_smith, does that make sense? ^
18:33	justin_smith	yeah
18:34	justin_smith	vIkSiT: in fact if you hand ring a var, ring decides "oh this is mutable, I have to make sure to check for the latest value each time I use it"
18:35	vIkSiT	justin_smith, ah
18:35	justin_smith	if ring didn't know how to handle vars, another option would be to pass in a handler function that derefs a var, or an atom, each time it is invoked
18:35	justin_smith	luckily we don't have to mess with that
18:35	vIkSiT	ah
18:35	vIkSiT	from what I can see, handler.clj contains (def app (app-handler [home-routes base-routes] ... )
18:36	vIkSiT	and (defroutes home-routes ... (..routes..))
18:36	amalloy	justin_smith: amusingly, (defn super-handler [req] (handler req)) would work as well as passing the var
18:38	amalloy	also, i don't know if you're intentionally simplifying this here, but ring really doesn't know or care about vars, only functions. it just works because vars, when called as functions, deref themselves
18:38	vIkSiT	hmm
18:38	vIkSiT	so this is actually compojure, and I see this: (defn get-handler [] (-> #'app ... ))
18:38	vIkSiT	(def app (app-handler [home-routes] .. ))
18:39	vIkSiT	so ultiamtely, the var here IS being passed in
18:39	vIkSiT	but still no joy in code reload. hmm
18:40	hiredman	vIkSiT: no, it isn't
18:40	vIkSiT	hmm?
18:41	vIkSiT	the var is for app but not home-routes?
18:49	tuft	does anyone know of a library for collecting/deferring side effects within a particular scope? nothing as hard core as the IO monad
18:50	tuft	(which i assume someone has recreated in clojure somewhere =)
18:57	justin_smith	tuft: how about building a sequence of thunks (functions of one argument) and later running them all in series?
18:59	nkozo	is possible to reference the instance created by proxy inside one of the proxy methods?
19:01	nkozo	found it, you can using "this"
19:02	tuft	justin_smith: i'm wondering how many puppies i'd kill if i collected them in an atom in a dynamically bound var someplace so they didn't need to be returned and passed along from every level in the call stack =)
19:03	justin_smith	heh
19:03	justin_smith	clearly, you also need (defonce dead-puppy-count (atom 0))
19:04	amalloy	i'm not sure dead puppies are better in a var than on the call stack anyway
19:04	amalloy	you just want them out of your program entirely
19:06	justin_smith	tuft: more seriously - depends on who uses your code, and what the chances are that it would be used by two separate parts of the same program
19:07	dbasch	justin_smith: (defonce shrodingers-cat (atom (rand-nth [:dead :alive])))
19:08	technomancy	dbasch: no, you need to make it part of a lazy seq
19:08	technomancy	that way it's literally in both states until it's observed
19:09	justin_smith	dbasch: (defer (rand-nth [:dead :alive])) both :alive and :dead until you deref it
19:09	dbasch	(inc justin_smith)
19:09	lazybot	⇒ 86
19:09	dbasch	(inc schrödinger)
19:09	lazybot	⇒ 1
19:10	justin_smith	(defer ((rand-nth [#(System/exit 0) #(println "survived")])))
19:11	tuft	justin_smith: yeah i guess returning data instead is the way to keep puppy mortality down
19:11	dbasch	justin_smith: that reminds me of my macro to execute the body or throw an excepton 1/n of the time at random
19:12	justin_smith	dbasch: the purpose?
19:12	dbasch	an excepton: a fundamental component of exceptions
19:12	justin_smith	dbasch: large exepton collider
19:12	dbasch	justin_smith: test random failures of a process that was trying to fetch stuff from the network
19:13	justin_smith	ahh, of course - simulate unrepliable infrastructure
19:13	cbp	(doc defer)
19:13	clojurebot	No entiendo
19:14	dbasch	(doc recursion)
19:14	clojurebot	Excuse me?
19:14	dbasch	wrong answer clojurebot
19:14	justin_smith	I don't know why I was doing "defer" - it's delay (and it does deferred evaluation)
19:15	justin_smith	(doc delay)
19:15	clojurebot	"([& body]); Takes a body of expressions and yields a Delay object that will invoke the body only the first time it is forced (with force or deref/@), and will cache the result and return it on all subsequent force calls. See also - realized?"
19:18	amalloy	justin_smith: just (def defer delay), so that you can run into the same problems with var redefinition
19:19	justin_smith	heh
19:19	amalloy	(modulo the baloney about setting ^:macro)
19:22	justin_smith	I refuse to look up "modulo the baloney" on urbandictionary
19:23	dbasch	amalloy: for proper behavior, wrap that in without-redefs from useless
19:23	amalloy	hah
19:24	dbasch	(defn maybe-or-maybe-not [x] true) <- also for useless
19:25	justin_smith	(def calculate (constantly 42))
19:25	dbasch	(defn perhaps [x] false)
19:30	amalloy	i can't believe ∀ isn't on any Compose-key sequence. surely Compose A v is obvious enough? but instead you get five different sequences that all result in ©
19:31	amalloy	how am i supposed to type stuff like ∀x i really don't recommend you look up x on urban dictionary
19:33	justin_smith	heh
19:33	justin_smith	http://www.urbandictionary.com/define.php?term=%E2%88%80
19:37	dbasch	∃x such that the urban dictionary entry for x is ∅
19:38	dbasch	or maybe ⊂ ∅
19:39	dbasch	no, belongs dammit
19:39	dbasch	∰ whatever
19:40	justin_smith	dbasch: x is a proper subset of the null set?
19:42	dbasch	I meant ∈
19:42	dbasch	but I can barely type regular ascii characters
19:43	justin_smith	dbasch: do you use emacs?
19:43	dbasch	I do
19:44	justin_smith	M-x insert-char allows globs and tab completion
19:44	justin_smith	you type in the name of the unicode symbol to insert it
19:44	justin_smith	☃ (SNOWMAN)
19:44	catern	woah
19:44	dbasch	∀your base, your base ∈ us
19:44	catern	that's cool
19:45	justin_smith	also M-x describe-char tells you the UNICODE NAME of the char so you can insert-char another time
19:45	nullptr	wow, never knew that λ
19:45	dbasch	I need to drop colloquy and consolidate inside emacs
19:45	nullptr	(inc emacs)
19:45	lazybot	⇒ 4
19:45	justin_smith	ie. ∈ is ELEMENT OF
19:48	justin_smith	at one point I had a piece of elisp code that collected every unicode symbol that had the property Ps (Punctuation, Open) and their matching Pe (Punctuation, Close) item
19:49	justin_smith	for ideas on how we could generalize clojure for more collection types
19:49	justin_smith	turns out there are hundreds of them...
19:51	verma	I've seen in some tbaldrige screencasts the fn is replaced by the lambda symbol, what sorcery is that?
19:51	justin_smith	there is an emacs mode for that (it only effects display, not file contents)
19:52	justin_smith	verma: http://www.emacswiki.org/PrettyLambda
19:52	verma	nice
19:53	justin_smith	that links to the more general pretty-symbol, and I think that has a clojure specific variant
19:53	verma	thanks!
19:53	verma	found this for vim: http://demonastery.org/2012/07/lambda-conceal-in-vim/
19:54	justin_smith	https://github.com/jimweirich/emacs-setup-esk/blob/master/pretty.el here's one for clojure lambda
19:54	verma	nice, thanks justin_smith
19:55	amalloy	justin_smith: that one refers to functions that don't exist unless you install ESK, like esk-pretty-lambdas
19:55	justin_smith	oh, yeah, don't use that
19:56	verma	oh no way! https://github.com/fwolanski/vim-clojure-conceal
19:56	verma	:)
19:57	technomancy	racket lets you just put λ directly in your code
19:58	justin_smith	clojure would let you do that too, but any collaborators would hate you for it
19:58	technomancy	pfff, collaborators
19:58	verma	is racket .. umm .. popular?
19:58	amalloy	probably has more users than clojure? i guess i'm not sure
19:58	technomancy	verma: it's got roughly 50% as many projects as clojure on github iirc
19:58	amalloy	it's in the ballpark, anyway
19:58	technomancy	so less popular, but not by an order of magnitude
19:59	verma	nice, it looks fun
19:59	technomancy	verma: it's great
19:59	amalloy	justin_smith: collaborators will hate you regardless
19:59	verma	technomancy, you writing any fun stuff in it?
19:59	justin_smith	,(def ☠ "touch this and die" ())
19:59	clojurebot	#'sandbox/☠
19:59	technomancy	verma: yeah. working on a hypercard clone.
20:00	nullptr	if you are using a very recent version of emacs, `prettify-symbols-mode' is a built-in
20:00	technomancy	verma: https://github.com/technomancy/cooper
20:00	nullptr	and by default you get lambdas in lisp-modes (clojure included)
20:00	technomancy	the gui and drawing libs especially are great
20:00	amalloy	like any time i give a talk about utility libraries or macros, the Q&A is like "but wait, won't people have to understand the new abstractions/shortcuts you wrote to understand your code?"
20:00	verma	technomancy, sweet! taking a look
20:00	amalloy	and it's like...do you really want to start every project at a base abstraction level of zero?
20:01	justin_smith	amalloy: but you define a function here - how can someone use that function without reading and understanding your code?
20:01	amalloy	justin_smith: that argument never convinces anyone, it turns out
20:01	amalloy	so anyway, those people will hate you regardless of what you do
20:01	hiredman	I love my unicode joins https://github.com/hiredman/graph/blob/master/src/com/manigfeald/graph.clj#L286-L296
20:01	catern	justin_smith: I can see you're putting to use the function you mentioned in #emacs
20:01	technomancy	amalloy: well, obviously the more you diverge from clojure.core, the more you're asking people to keep in their heads
20:02	technomancy	it's a matter of cost/benefit
20:02	justin_smith	catern: I'm in #emacs?
20:02	dbasch	amalloy: before I start a new project, I go to the beach and bring a bucket of sand so I can make my own nand gates
20:02	verma	hiredman, how do people type those in?
20:02	justin_smith	catern: or you mean I used insert-char SKULL AND CROSSBONES - yeah
20:02	hiredman	I read somewhere if you use non-blocking io you can scale up human understanding by 10x
20:03	hiredman	verma: I use M-x ucs-insert and completion
20:03	catern	justin_smith: yeah, sorry, I just assumed that I was in #emacs when I saw that before
20:03	verma	hiredman, hmm, nice
20:04	dbasch	technomancy: I guess his point is that if you make (defmacro fetch) happen, then people don’t have to look it up every time they see it
20:04	amalloy	technomancy: not really. if some utility helps compute whatever my program does, then i have three choices: (1) don't use that utility, inlining something like it whenever necessary; (2) define the utility in my program and reuse it there; (3) use the utility from my utility project
20:04	amalloy	(2) and (3) are the same except for where the code is located, and arguing for (1) is arguing that you shouldn't build abstractions
20:05	amalloy	in all cases, whoever reads my code has to understand whatever the utility function would do
20:05	technomancy	amalloy: oh you're talking about separate libs specifically
20:05	justin_smith	catern: #clojure goes off topic a lot but not nearly as much as #emacs
20:06	catern	justin_smith: hey what's wrong with that
20:06	technomancy	verma: let me know what you think if you try it
20:06	verma	technomancy, sure, starting to play with racket a little bit
20:07	technomancy	verma: I'm working on a blog post about that project specifically, and then I hope to follow up with one on FP in racket more generally
20:07	technomancy	verma: take a look at fstruct.rkt for more on that topic; should help you feel more at home coming from clojure
20:07	verma	nice
20:08	technomancy	structs that are callable like functions and support the dictionary interface
20:09	technomancy	racket is mostly FP-friendly, but the default structs feel like they're more designed for imperative work
20:09	technomancy	easy fix though =)
20:16	kenrestivo	hiredman: what is this ⨝ ?
20:19	amalloy	kenrestivo: 0x2A1D JOIN
20:21	dbasch	I just realized that the ‘decode’ part of this library doesn’t even work https://github.com/talkto/geohash
20:22	dbasch	the example given in the readme encodes something and then decodes to something different
20:25	hiredman	http://en.wikipedia.org/wiki/Relational_algebra
20:25	hiredman	(not that I used it as a natrual join)
20:26	hiredman	http://en.wikipedia.org/wiki/Relational_algebra#.CE.B8-join_and_equijoin
20:30	kenrestivo	hiredman: thanks
20:41	Ymesio	Hi all
20:41	Ymesio	So I have a collection of numbers, say 1,2,3,4
20:42	Ymesio	I need to map over it, but what I need is not the Nth value, but aclually the list with Nth value removed
20:42	Ymesio	So I would get 2 3 4 then 1 3 4 then 1 2 4 then 1 2 3
20:42	Ymesio	What would be the best way to do that?
20:43	justin_smith	is the order important?
20:44	Ymesio	Not really
20:45	justin_smith	,(let [input [1 2 3 4]] (map #(disj (set input) %) input))
20:45	clojurebot	(#{4 3 2} #{1 4 3} #{1 4 2} #{1 3 2})
20:45	justin_smith	you could do something less elegant with remove and an equality predicate if ordering was important
20:49	Ymesio	justin_smith: Looks like that could work thanks a lot
20:49	justin_smith	,(let [input [1 2 3 4]] (map #(remove #{%} input) input))
20:49	clojurebot	((2 3 4) (1 3 4) (1 2 4) (1 2 3))
20:49	justin_smith	an alternative
20:49	justin_smith	I like the former better though (as long as unordered sets are OK of course)
20:52	Ymesio	I’d assume disjunction is be constant
20:52	Ymesio	* should be
20:54	Ymesio	justin_smith: Thanks, will use the first one
20:54	justin_smith	yeah, there is the overhead of creating the set once, but disj is constant time
20:55	justin_smith	exactly
20:55	amalloy	justin_smith: that's not much good if you have duplicate elements
20:56	justin_smith	yes, that's also an important point
20:56	amalloy	you knida need a frequency map instead of a set, if you want to handle that possibility
20:56	Ymesio	I don’t have any duplicates
20:58	wei	did filter-key get removed?
20:58	Ymesio	justin_smith: thanks again
20:58	justin_smith	Ymesio: np
20:59	justin_smith	wei: looks like it is private? http://www.clodoc.org/doc/clojure.core/filter-key
21:00	justin_smith	(doc clojure.core/filter-key)
21:00	clojurebot	"([keyfn pred amap]); "
21:00	justin_smith	$source clojure.core/filter-key
21:00	lazybot	clojure.core/filter-key is http://is.gd/VSfdpE
21:00	justin_smith	well, lazybot gives us the 1.4 version...
21:01	dbasch	Ymesio: you can do (concat (take n x) (drop (inc n) x))
21:01	justin_smith	https://github.com/clojure/clojure/blob/master/src/clj/clojure/core.clj#L3923 but yeah, still private
21:01	wei	is there a public function to return key-value pairs where the key fits a predicate? i guess it’s not too hard to write it, but i always trust core functions’ performance :)
21:01	dbasch	or something to that effect
21:01	Ymesio	,(concat (take n x) (drop (inc n) x))
21:01	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: n in this context, compiling:(NO_SOURCE_PATH:0:0)>
21:02	justin_smith	Ymesio: definitely not constant time, but that is definitely another approach
21:03	dbasch	,(let [n 2 x (range 5)] (concat (take n x) (drop (inc n) x)))
21:03	clojurebot	(0 1 3 4)
21:04	justin_smith	,(let [input {1 :a 2 :b 3 :c 4 :d}] (select-keys input (filter even? (keys input)))) ; wei
21:04	clojurebot	{2 :b, 4 :d}
21:04	wei	justin_smith: fair enough, thanks
21:04	wei	(inc justin_smith)
21:04	lazybot	⇒ 87
21:16	gfredericks	reiddraper: I'm watching this shrink that has taken the 2nd child for about the 400th time straight and realized I could do a kind of binary search down the shrink tree to jump to wherever that pattern quits
21:21	justin_smith	gfredericks: out of context you sound like a weird parent talking about his kid's psychologist
21:21	catern	yes
21:21	catern	i just flipped to this channel in IRC and that's how I interpreted
21:21	catern	it
21:25	danneu	i upgraded cider and now my cider-error buffer briefly flashes an error before going blank. i have to C-c C-z to see the error on the repl
21:25	danneu	https://dl.dropboxusercontent.com/spa/quq37nq1583x0lf/oth82eom.png
21:27	justin_smith	~cider
21:27	clojurebot	cider is Cider is unstable and broken right now, most things don't work. Use the last stable version of nrepl.el for now.
21:27	justin_smith	heh, I wondered what clojurebot had to say about that
21:27	amalloy	probably not far off
21:28	justin_smith	~nrepl
21:28	clojurebot	nrepl is a network REPL implementation: http://github.com/clojure/tools.nrepl
21:28	justin_smith	~slime
21:28	clojurebot	Titim gan éirí ort.
21:28	arrdem	dbasch: any solutions to that recovery prolblem?
21:28	dbasch	not yet
21:29	dbasch	in casee someone is interested here, I shuffled a paragraph from a fairly popular book: http://pastebin.com/raw.php?i=GGhh3WA2
21:29	dbasch	the idea is to recover it
21:30	justin_smith	translation of that factoid above: "May you fall without risinge"
21:30	justin_smith	(sic)
21:32	grandy___	anyone here used secretary?
21:32	grandy___	~secretary
21:32	clojurebot	Huh?
21:32	dbasch	I believe seangrove did
21:32	grandy___	seangrove: true?
21:33	grandy___	trying to figure out the best way to navigate between "pages" and update the url shown in the browser
21:33	dbasch	grandy___: at least it’s in this app https://github.com/sgrove/omchaya/blob/fe5861e7f483e0f6ac2b1685dfaca2c680e36c32/src/omchaya/routes.cljs
21:34	grandy___	dbasch: hmm looking
21:34	grandy___	dbasch: he's not handling the use case i'm curious about
23:02	cfleming	arrdem: BTW looks like there's an old, non-functioning Grimoire at http://www.arrdem.com/grimoire/ - you might want to redirect to the new one
23:12	arrdem	cfleming: yeah that is an old version.. I thought it was redirecting
23:12	arrdem	cfleming: I'll check it out, thanks
23:12	cfleming	arrdem: NP
23:13	cfleming	arrdem: BTW something I like a lot about the new ClojureDocs is that I can navigate it without much mousage. I like the Grimoire narrow-down search, but if I type, say, cond-> into the search box, enter doesn't take me to it - that would be really nice.
23:13	cfleming	arrdem: The crossclj integration is awesome BTW.
23:35	celwell	How could I make map that returns a certain value when a requested key does not exist?
23:36	justin_smith	celwell: it takes an extra arg for that
23:36	justin_smith	,({} :a :not-found)
23:36	clojurebot	:not-found
23:36	justin_smith	if you need to hard code a default, maybe you need a function and not a map?
23:38	celwell	justin_smith: maybe, i was hoping to not use a function though. I'd like to have something like:
23:38	celwell	(def form-id-aliases
23:38	celwell	{1 {:patient-questionnaire [2 4 5 6 7 8 9 11]}
23:38	celwell	2 {:patient-questionnaire [2 4 5 6 7 8 9 11 13 14]}
23:38	celwell	:not-found {:patient-questionnaire [2 4 5 6]}})
23:38	celwell	I guess there's no simple way to do that?
23:39	justin_smith	you could use a custom lookup function and pass both the map and key, and let the lookup function specify or find the default
23:39	justin_smith	finally, it is actually possible to extend the interfaces and protocols that a map does, with custom defaulting behavior, but that may be more work than is worth it
23:39	celwell	is it possible to make a 'lazy-map
23:40	celwell	' ... that fills in all the missing vals
23:40	justin_smith	not with the standard map type, no
23:40	celwell	hmm.. ok I'll probably have to just use the :not-found thing in a ll my lookups
23:41	justin_smith	(defn get-with-default [m k] (m k (:not-found m)))
23:41	justin_smith	you can probably give it a less messy name
23:42	celwell	yeah, thanks
23:43	ToxicFrog	,(let [my-map {:a 1 :b 2 :not-found "kittens"} my-map-with-default #(my-map % (my-map :not-found))] [(my-map-with-default :a) (my-map-with-default :z)])
23:43	clojurebot	[1 "kittens"]