#clojure – 2013-10-05

2013-10-05

00:15	bja	ugh, ported codebase to latest cljs and core.async, promptly found out that specljs makes use of cljs.core.format
00:21	chare	I return
00:22	frozenlock	I have a website (called "A") on compojure. I have another website (called "B") on another server accessed via ssh. Is it possible to access B's website throught A? With an iframe perhaps?
00:25	xeqi	frozenlock: are you port forwarding?
00:25	frozenlock	I can, yes.
00:26	xeqi	also, are you looking for a proxy server to point to B ?
00:27	frozenlock	Yes.
00:27	frozenlock	Well "A" should become a proxy.
00:27	frozenlock	I wonder if it's possible to incoporate it in the compojure framework however...
00:28	frozenlock	say current "A" url---> /some-url/hello and then the "B" /welcome/item1. When passing throught A ---> /some-url/hello/welcome/item1
00:29	frozenlock	Am I crazy? :p
00:30	xeqi	frozenlock: possibly. 1) Is the ssh access for security? 2) Does "B" use any absolute url's in it's html/js/css ?
00:31	frozenlock	1) it's nice if it can be secure, but it's more for NAT traversing 2) "B" is also compojure; I have absolute power over it.
00:35	xeqi	frozenlock: I don't know of anything prebuilt. You could make a wildcard route and use clj-http to talk to "B" over a forwarded ssh port, but you'd have to be careful with passing cookies all the way through
00:37	frozenlock	Oh I see... so "A" request any required stuff from "B" via clj-http and then it uses it as its 'own' and give it to the user.
00:38	xeqi	assuming I understand your problem correctly, yes
00:39	frozenlock	I think you do, and your solution makes perfect sense, thanks :D
00:41	frozenlock	And the "B" server is very simple... I think it doesn't even need cookies (it simply uses GET/POST for basic browsing), so that should be quite straightforward.
00:42	xeqi	frozenlock: one question is if "A" could just do what "B" is doing, but I assume the NAT traversal gives "B" access to different resources (like a db)
00:42	frozenlock	In short, pretty much.
00:53	frozenlock	Wow... I wasn't expecting to find something like that for clojure o_O https://github.com/hugoduncan/clj-ssh
01:59	sm0ke	is there a variant of assert which return the expression value instead of nil?
02:01	ambrosebs	sm0ke: you'll probably need to write your own
02:05	sm0ke	ambrosebs: got it i defined assert# .. dont know what else to call it (defn assert# [n] (assert n) n)
02:29	mullr	sm0ke: how about 'non-nil'? (+ a (non-nil (do-something)))
02:30	sm0ke	,(doc non-nil)
02:30	clojurebot	Huh?
02:33	muhoo	,non-nil?
02:33	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: non-nil? in this context, compiling:(NO_SOURCE_PATH:0:0)>
02:33	muhoo	,nik?
02:33	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: nik? in this context, compiling:(NO_SOURCE_PATH:0:0)>
02:33	muhoo	,nil?
02:33	clojurebot	#<core$nil_QMARK_ clojure.core$nil_QMARK_@c18ba8>
02:41	mullr	sm0ke: Sorry, I mean as a different name for the function you wrote and called 'asset#'
02:46	mullr	('assert#', rather)
03:01	dcunit3d	got a question for using quil (processing for clojure)
03:02	dcunit3d	so i've got a project that uses incanter
03:02	dcunit3d	and incanter includes charts that allow you to graph functions and data easily
03:02	dcunit3d	but it doesn't allow you to work with images very easily.
03:03	dcunit3d	so i'm looking at either using seesaw (swing) or quil (processing)
03:03	dcunit3d	i've explored a little with both, but i'm trying to double buffer the images i'm adding.
03:05	dcunit3d	quil is pretty straightforward. i can instantiate a PImage and directly copy a row of data into the pixels array. but then that means i'm working with 100 PImage objects with each refresh of the image.
03:06	dcunit3d	will that result in a slowdown? and how do i ensure that the resources required for these objects is released. is there a strategy where i can just instantiate 100 PImage references to be used. and then just update the same objects each time, so the objects don't need to be instantiated?
03:17	dusty_col	hi
03:17	dusty_col	Q: how do I make a list of chars (\A \B \C) into a string? calling (str) on it doesn't seem to do it, makes a str containing the parens
03:18	TEttinger	hey dusty_col. ##(apply str [\A \B \C])
03:18	lazybot	⇒ "ABC"
03:18	TEttinger	(apply str [\A \B \C]) is what you're after
03:18	dusty_col	looks up apply
03:19	TEttinger	apply takes a function and a collection, and uses the collection as args to the function.
03:19	dusty_col	sweet, that's what i was looking for. thx!
03:19	TEttinger	,(apply + [1 2 3 4 5])
03:19	clojurebot	15
03:19	dusty_col	,(println "Thanks")
03:19	clojurebot	Thanks\n
03:19	TEttinger	haha np
03:19	TEttinger	next up: map and reduce
03:25	dusty_col	lol yea i am doing exercism.io
03:25	dusty_col	had to loop over string and replace chars
03:25	dusty_col	with loop/recur
03:25	dusty_col	or that's how i did it anyways
03:26	TEttinger	there's also clojure.string/replace: ##(doc clojure.string/replace)
03:26	lazybot	⇒ "([s match replacement]); Replaces all instance of match with replacement in s. match/replacement can be: string / string char / char pattern / (string or function of match). See also replace-first."
03:26	dusty_col	well that's a little too easy, i think the point of the exercise is learning how to recurse
03:27	TEttinger	,(clojure.string/replace "Chicken" \C \T)
03:27	clojurebot	"Thicken"
03:28	TEttinger	yeah, recursion is important too
03:28	frozenlock	I think I had to recurse 2 or 3 times total :-/
03:28	frozenlock	Must be doing something wrong...
03:28	frozenlock	*I
03:28	TEttinger	nope, frozenlock
03:28	TEttinger	you shouldn't need to do it often, but all the standard lib is built around it
03:29	TEttinger	so it just helps to be able to read code using it
03:29	frozenlock	great :)
03:29	frozenlock	It's also a pain to write, IMO :p
03:29	TEttinger	indeed.
03:29	TEttinger	especially compared to more declarative stuff like map
03:29	dusty_col	so i'm trying to get a job at a clojure shop
03:29	dusty_col	but i can barely write hello world
03:30	TEttinger	4clojure!
03:30	dusty_col	what is a good roadmap to get up to speed? topics & projects wise
03:30	dusty_col	TEttinger: I find 4clojure confusing, I often don't udnerstand the questions. Some are helpful.
03:30	TEttinger	they
03:30	TEttinger	they're meant to be kinda obtuse I think
03:30	TEttinger	to make you come at the problem from multiple angles
03:31	dusty_col	a buddy suggested something like arithmetic, strings, control structures, functions, io, little web app..
03:31	TEttinger	learning the standard FP stuff is most important in the long run. it also depends on those things.
03:32	TEttinger	so... map, reduce, apply, into, comp, potentially juxt, how lazyseqs work...
03:32	TEttinger	probably in around that order, juxt and comp are just cool stuff
03:33	TEttinger	but not needed
03:33	TEttinger	oh, filter too
03:33	TEttinger	filter is easy enough
03:34	TEttinger	,(filter (fn [item] (> 10 item)) [1 2 3 4 5 10 11 12])
03:34	clojurebot	(1 2 3 4 5)
03:34	frozenlock	dusty_col: just don't "(map #(some-fn %) [1 2 3])" like I did for like a month :p
03:35	dusty_col	frozenlock: why not, what's wrong with map
03:35	TEttinger	nothing
03:35	TEttinger	it's the #(some-fn %)
03:35	TEttinger	which is the same as some-fn
03:35	TEttinger	just slower
03:36	dusty_col	oh
03:36	frozenlock	and more verbose
03:36	frozenlock	for absolutely nothing
03:36	dusty_col	oh he's making a closure to call the function with it's parameter?
03:36	dusty_col	i might understand ;)
03:36	TEttinger	yes, which is what the function name on its own does already
03:37	TEttinger	,(time (map #(inc %) [1 2 3]))
03:37	clojurebot	"Elapsed time: 0.121924 msecs"\n(2 3 4)
03:37	TEttinger	,(time (map inc [1 2 3]))
03:37	clojurebot	"Elapsed time: 0.035407 msecs"\n(2 3 4)
03:37	sveri	hi, i am trying to get the last value from a list, now when i do ((fn [x] (comp first reverse x)) '(1 2 3)) i get a function definition back instead of the last value, how do i use comp correctly? (doing ((fn lll [x] (println (first (reverse x)))) '(2 3 4)) works in the repl)
03:39	TEttinger	(fn [x] ((comp first reverse) x))
03:39	TEttinger	comp returns a function
03:39	TEttinger	you want to call the function I think
03:40	TEttinger	but why not use last?
03:40	TEttinger	,(last '(1 2 3))
03:40	clojurebot	3
03:41	TEttinger	sveri?
03:42	chare	guys here is my update on my progress
03:42	chare	I'm reading http://www.arcsynthesis.org/gltut/Positioning/Tut04%20Perspective%20Projection.html
03:42	chare	whats your guys progress on starcraft clone project?
03:44	chare	Tettinger update on your project please?
03:44	sveri	TEttinger: ah, that works, thank you very much
03:44	TEttinger	no prob
03:44	TEttinger	comp is tricky, I only recently started using it. it's nice
03:45	sveri	TEttinger i am doing the 4clojure tasks and looked for some different solutions
03:45	TEttinger	ah.
03:45	frozenlock	ditto. I don't use it often however... mostly only to reduce the number of parens.
03:45	TEttinger	there's also #(nth % (dec (count %))) I believe
03:46	sveri	TEttinger yea, and a recur version which i like most
03:47	sveri	(fn [[x & xs]] (if xs) recur xs) x), however, i wonder why i need two [[ instead of one [? do you know that?
03:47	TEttinger	it's a destructuring
03:48	TEttinger	it really takes one arg, but converts it to the head x and the & rest as a sequence xs
03:48	sveri	TEttinger ok, i guess i understand that
03:50	TEttinger	so if you did with one [
03:52	TEttinger	(fn [x & xs] (if xs) recur xs) x) ;; this takes 1 or more args, and will act really weird because it won't have the same type for x on the first call (the-fn 1 2 3) starts with x as 1 and xs as [2 3], the recursion recurs with x as [2 3] and no xs
03:53	TEttinger	gah that wasn't very clear
03:55	sveri	TEttinger but i think i got it
03:55	sveri	:-)
03:58	frozenlock	Wasn't there someone trying to implement TCO for clojure?
04:15	chare	lets talk about something
04:15	chare	i'm bored
04:16	jonasen	frozenlock: https://github.com/cjfrisz/clojure-tco
04:20	frozenlock	jonasen: last commit 11 months ago :-/
04:20	frozenlock	So it's not getting inside clojure.core I assume...
04:21	jonasen	tco will not get into core before java supports it
04:26	cark	jonasen: that's to say ..never
04:27	cark	so annoying =(
04:27	jonasen	cark: that's probably the case
05:14	dcunit3d	does anyone have experience working with BufferedImages or graphics and clojure
05:18	chare	use opengl
05:35	TEttinger	dcunit3d, some, what's up?
05:37	TEttinger	(BufferedImage. 50 50 BufferedImage/TYPE_4BYTE_ABGR) ;; is a line in some font drawing code i have
05:37	dcunit3d	i'm trying to display handwritten digit data in images, using seesaw (swing) or quil (processing)
05:38	TEttinger	display and just display, or save as png or something?
05:38	dcunit3d	i want to display them on a JPanel or something
05:39	dcunit3d	but i want to read in 100 digits and display them as they are being processed
05:39	TEttinger	ok.
05:39	TEttinger	why an image?
05:39	TEttinger	can't you use swing fields?
05:40	dcunit3d	i've read the image data into the program and so i'm trying to display it
05:41	TEttinger	ok, in swing it shouldn't be hard. let me look it up
05:41	TEttinger	what kind of data is it? just a vector?
05:41	TEttinger	vector of bufferedImages?
05:41	dcunit3d	i also want to display the hidden layer's of the neural network, so you can see them as they change.
05:42	dcunit3d	the data i've reading in is just a persistent vector, containing 784x1 vectors each representing an image
05:43	dcunit3d	each image is 28x28, but they are unrolled
05:44	dcunit3d	i can use quil to easily write to the pixels array of a PImage. and pretty much just set the pixels directly with with the 784x1 vector.
05:45	dcunit3d	but that requires instantiating a 100 PImage objects, and then I'm worried about memory consumption.
05:45	TEttinger	HAHAHAHAHAA Oracle Enterprise Search is temporarily unavailable.
05:45	TEttinger	WHAT
05:45	dcunit3d	lol
05:45	chare	dcunit3d: just use opengl
05:46	dcunit3d	what libraries are available for it? there's penumbra, but it hasn't been updated in a while
05:46	TEttinger	http://www.docjar.com/docs/api/java/awt/image/BufferedImage.html
05:47	TEttinger	so what digit data is this
05:47	TEttinger	is it just 0-9?
05:47	TEttinger	or fingers?
05:47	dcunit3d	http://yann.lecun.com/exdb/mnist/
05:47	dcunit3d	0-9
05:48	TEttinger	ohhhhh
05:48	dcunit3d	i used gloss to parse the binary data. and i'm planning on using incanter to process the data.
05:48	TEttinger	I thought you meant number data, you mean images of numbers made by hand... that makes sense now
05:49	dcunit3d	https://github.com/dcunited001/handwritten-digits/blob/master/src/handwritten_digits/draw.clj
05:49	TEttinger	so if someone types 99999, it should show 5 different writing styles of "9"?
05:50	dcunit3d	basically it reads in each digit image and label and trains them. then there's a set of digits where it tries to guess which one it is.
05:51	dcunit3d	so it's handwritten digit recognition.
05:51	TEttinger	ah.
05:51	dcunit3d	i don't really need graphics, but it'd be cooler if it did
05:52	TEttinger	of course!
05:52	TEttinger	so you want to draw...
05:53	dcunit3d	yeh, but i'm having a hard time getting swing set up. and i'd like for the graphics to be independent of the data being processed.
05:54	dcunit3d	or i'm trying to figure out the best way to split up the data processing and the images.
05:54	TEttinger	I don't really know how I can help yet...
05:54	chare	dcunit3d: just use opengl through JOGL
05:54	TEttinger	sorry.
05:57	dcunit3d	thanks anyways
05:57	dcunit3d	i'm not sure i'm asking the right thing
05:59	chare	opengl...
05:59	chare	not hard...
06:01	TEttinger	dcunit3d, it sounds like a cool program though
06:10	dcunit3d	chare: are there any good examples of working with images in JOGL?
06:10	chare	you do the usual opengl stuff nothing special
06:11	dcunit3d	i've never done opengl stuff
06:12	TEttinger	dcunit3d: it looks like you're mostly doing close-to-the-metal graphics stuff
06:13	TEttinger	maybe you could do this with just seesaw, I dunno
06:13	TEttinger	can you take the code you posted and make a gist or something that has some possible things to fill in later?
06:14	dcunit3d	yeh, ill do that
06:14	chare	dcunit3d look the easy thing to do is just demand TEttinger write the code for you and start getting abusive if he doesn't help, thats what i do
06:15	dcunit3d	lol
06:15	dcunit3d	i'm trying to get some advice. i want to write it myself.
06:17	dcunit3d	here's a cool project with some examples. it uses quil and jogl.
06:17	dcunit3d	https://github.com/quephird/nehe-quil
06:17	dublindan	Hey, I'm having trouble with compojure routes.. can someone help me out a bit?
06:18	dcunit3d	but it has some windows-specific dependencies in the project.clj
06:18	dcunit3d	dublindan what kind of problems?
06:19	dublindan	dcunit3d: I'm using luminus in case it matters. If I run the template code, it works fine, but when I change it I can't load anything other than /
06:19	dublindan	It doesn't fall through to the not-found handler, it just doesn't load anything
06:20	dcunit3d	is there anyway to list the routes that are configured?
06:20	dublindan	I don't know, I'm not familiar enough with ring/compojure yet..
06:23	dublindan	Hmm, odd, I just started a new blank project and added a new route and that worked.. guess I need to tinker more, must have broke something somewhere :-/
06:24	dcunit3d	neither am i, haven't done webdev with clojure yet
06:25	dublindan	I used compojure about two years ago and had no problems, but haven't really used it since and been away from clojure for almost a year.. so very much not up to speed anymore
06:27	dublindan	weird, I think its working now, but I did not change anything
06:27	dublindan	must be a configuration thing then
07:04	dublindan	Does anybody know how to use Enlive's auto-reloading? Placing (net.cgrand.reload/auto-reload ns) into the file with my templates in it doesn't work.
07:26	klrr_	okey, this question might seem a bit crazy, but since i found monadic streaming IO (http://richhickey.github.io/clojure-contrib/monadic-io-streams-api.html) is there any library that provides similar monadic IO as haskell or is that one too dependent on haskell's type system?
07:45	mklappstuhl	hey there
07:46	mklappstuhl	I'm just arguing with a friend over using keywords vs strings as keys in maps
07:48	mklappstuhl	or not only in maps but as property of an object type we have in our application
07:50	mklappstuhl	It's the ticker of stock symbols. in some places (maps with ticker symbols as keys) it makes things easier to have them as symbols instead of strings but on the other hand I feel like making them keywords increases complexity and could introduce wierd conversions here and there
07:51	cark	keywords are good as keys, when you need to use them in your code. On the other hand, if it's data, you might want to keep them as string
07:53	cark	for instance it's cool to have databse fields as keywords, because you use these in your code
07:56	cark	but i wouldn't keywordize customer names or customer ids
07:58	lutra	khm, hi?
09:05	wakeup	Hi
09:06	wakeup	Somebody familiar with the cllojure.java.jdbc API? I am wondering is there is a way to open a connection, reuse it and manually close it afterwards.
09:07	joegallo	it's just a java.sql.Connection, so... yes
09:08	joegallo	https://github.com/clojure/java.jdbc/blob/master/src/main/clojure/clojure/java/jdbc.clj#L753
09:08	joegallo	call connection yourself, and then do your calls, too, but you'd have to deal with the binding of db
09:09	yedi	so for many of my views, I pull the current user from the session, however I want to test various views / fns from the repl
09:09	wakeup	joegallo: with-connection is deprecated. And how do I get a connection in the first place?
09:09	joegallo	don't pay attention to that
09:09	yedi	is there a preferred way to do this simply?
09:10	wakeup	joegallo: There is get-connection, which requires an existing open connection?
09:11	joegallo	with-connection, which i linked to, is calling get-connection
09:11	joegallo	which takes a db-spec
09:11	utkarsh	How can I write a macro "q" which does this: (q (hello) (world)) == '((hello) (world)) ?
09:14	utkarsh	I mean such that (= '((hello) (world)) (q (hello) (world))) returns true
09:15	joegallo	(defmacro q [& body] `'~body)
09:16	utkarsh	joegallo: thanks!
09:16	joegallo	that said, what do you need it for, utkarsh?
09:17	joegallo	i mean, what's the big difference between (q (hello)) and '((hello))?
09:17	utkarsh	joegallo: was just curious mainly
09:17	joegallo	k
09:18	joegallo	i mean, for that matter, q is a built-in
09:18	joegallo	it's called quote
09:18	joegallo	ah, well, not quite
09:18	joegallo	,(quote (hello))
09:18	clojurebot	(hello)
09:18	joegallo	,(quote (hello) (world))
09:18	clojurebot	(hello)
09:18	joegallo	yeah, small different there
09:18	utkarsh	joegallo: yep, that's why I was curious, quote was just returning the first param
09:33	TimMc	utkarsh: 'foo is (quote foo)
09:33	TimMc	&''''''foo
09:33	lazybot	⇒ (quote (quote (quote (quote (quote foo)))))
09:44	sm0ke	is possible to debug lisp code in the traditional way by setting breakpoints and stuff?
09:44	sm0ke	i dont find any ide which does that
09:51	wakeup	sm0ke: it's not very desirable, we have the REPL, STEP, and BREAK.
09:52	wakeup	also TRACE
09:52	wakeup	(I am talking in terms of CL, don't know what clojure's counterparts are)
09:52	sm0ke	wakeup: clojure has repl for sure
09:52	sm0ke	:P
09:53	wakeup	sm0ke: actually I wouldn't call that a REPL but you, something like it
09:53	wakeup	s/you/yeah
09:53	sm0ke	wakeup: whats a repl?
09:54	wakeup	sm0ke: it involves not throwing java stack traces
09:54	wakeup	conditions/restarts, the like
09:55	sm0ke	wakeup: so you mean to say that in common list you litter your code by writing (break) every where?
09:55	sm0ke	common lisp*
09:55	wakeup	Yo but you can use BREAK to set breakpoints.
10:29	pyykkis	hi. I'm planning to run a set of io limited operations parallel without need for coordination.
10:29	pyykkis	should i use futures or core.async go?
10:30	pyykkis	I'm not even interested about the results, operations write to a separate files as a side effect
10:39	jonasen	pyykkis: I'd go with futures
10:55	pyykkis	jonasen: any rationale? I'd love to learn. I made a quick spike and it seems with futures main thread is automatically waiting for thread pool to finish.
10:55	teemu_f	Hi, I'm struggling with learning map destructuring. Any good tutorials on that topic?
10:56	pyykkis	jonasen: with go blocks, i needed to set up a channel for coordinating main thread not to exit before go blocks are done.
10:57	pyykkis	teemu_f: If you can grab a book, here's the best tutorial i've found: http://www.clojurebook.com/
10:58	teemu_f	pyykkis: thanks, I already have it
10:58	pyykkis	teemu_f: here's a compact but through explanation http://clojure.org/special_forms#Special Forms--Binding Forms (Destructuring)
11:01	teemu_f	pyykkis: ok, I just have to practice more in repl :)
11:24	jonasen	pyykkis: I'm no expert, just seems like core.async is overkill... You could also look at pmap
11:24	`cbp	just map futures and then map deref over them
11:25	`cbp	unless your collection is hundreds of items that works fine
11:25	jonasen	`cbp: It there were 100s of items, wouldn't pmap be a good choice?
11:26	arkh_	I haven't needed a clojure contrib library for a while - where is cond-let ?
11:26	`cbp	jonasen: you'd have to partition them
11:28	`cbp	jonasen: i'd prolly go the core.async route on that though. It's hard for me to find a use case for pmap
11:44	faust45	hi guys
11:44	faust45	what is the best way to debug my app ?
11:44	faust45	from repl
12:27	tshauck	Hi, what would be a good way to go about applying a function to the first column in a vector of vectors (used to be a csv file)
12:32	`cbp	tshauck: apply map vector
12:32	`cbp	tshauck: that transposes the matrix
12:32	`cbp	er vector of vectors w/e
12:45	tshauck	`cbp: Ok, I'll give that a try... the big picture is I want to parse a date string in the first "column", then group by the month from the resulting date, and sum the second "column"
12:46	ruzu	does not knowing java hurt learning clojure? i really don't want to learn java. i fear for my soul. :'(
12:46	tshauck	`cbp: I'd like to get the rows as [date number] but maybe this isn't the best way to go about it?
12:52	jkj	hello android clojure developers
12:52	jkj	i have some trouble getting repl to run
12:52	jkj	the application starts though... should i start the repl someway from my app
12:54	`cbp	tshauck: you'll need to give an example I can't really help you when I'm just guessing
12:55	`cbp	ruzu: plenty of people learn clojure without knowing java
12:56	`cbp	ruzu: tchnomancy here previously that you only need to know clojures std lib to use clojure
12:56	`cbp	said*
12:57	`cbp	tshauck: ##(let [x [[1 2] [3 4]]] (apply map vector x))
12:57	lazybot	⇒ ([1 3] [2 4])
12:57	coventry	ruzu: You end up picking up a lot of information about the java ecosystem by osmosis, but it doesn't seem to harmful when that happens on an as-needed basis.
12:58	tshauck	`cbp: heres and example of my data and a bit of a desc: https://gist.github.com/tshauck/6842961
13:03	`cbp	tshauck: something like this? https://www.refheap.com/19447
13:05	tshauck	`cbp: I think that get me going, thanks
13:26	teemu_f	I'd appreciate any help with this gist: https://gist.github.com/tfrisk/6841473
13:29	`cbp	teemu_f: doseq is for sideeffects like printing, and it returns nil. If you wanna return values from a collection use for instead of doseq
13:30	`cbp	teemu_f: but for your use case i'd use filter
13:31	teemu_f	I was just thinking filters when I took a break..
13:31	teemu_f	sometimes you just have to stop staring your code
13:31	`cbp	teemu_f: just replace doseq with for and it should work
13:33	teemu_f	thanks, now I get a vector
13:34	coventry	What does mjolnir have to do with datomic?
13:34	teemu_f	maybe I'll call it a day and continue tomorrow with fresh brains..
13:38	coventry	Oh, I see. It's using datomic to track aspects of the program it's building.
13:52	dublindan	How do I get all permutations of pairs of two lists? Thought I saw a function for it earlier, but can't seem to remembr the name of it now..
13:55	ambrosebs	dublindan: list comprehension with `for`?
13:55	dublindan	ambrosebs: ok, thanks
14:19	bolted	Is it acceptable to ask for 4clojure help in here?
14:20	andyfingerhut	I'm pretty sure that is on topic
14:21	nDuff	bolted: there _used_ to be an explicit policy of "no project euler", but I don't think that's still the case. And, for that matter, I could be mixed up with #python.
14:21	nDuff	Go ahead and ask, anyhow. :)
14:22	bolted	Okay, thank you :) I'm working on #28, "flatten a list." http://www.4clojure.com/problem/28
14:23	noonian	what have you tried so far?
14:25	bolted	Right now, the idea in my head is: define a function called my-flatten [xs], then 1) look at the first element, 2) If it's not a collection, conjoin (first xs) to (my-flatten (rest xs))
14:27	noonian	ok, that makes sense, what if it is a collection
14:28	bolted	if it is a collection, (conj (my-flatten (first xs)) (my-flatten (rest xs)))
14:29	bolted	But this always stack overflows, and 1) I'm not sure which branch is overflowing and 2) In my head, we should always hit the base case, where the first element isn't a collection
14:29	noonian	ah
14:30	gfredericks	how do you test if it's a collection?
14:30	bolted	(if (coll? (first xs)) ...)
14:30	gfredericks	,(coll? nil)
14:30	clojurebot	false
14:30	gfredericks	k I don't know why it stack overflows then.
14:31	gfredericks	could you paste a full expression that stack overflows so we can look at it?
14:31	gfredericks	(refheap.com)
14:31	noonian	yeah, it sounds like your logic is pretty sound but the implementation might be flawed
14:31	bolted	Sure. Let me get it back to the state it was in before, I mangled it trying to debug it
14:34	andyfingerhut	,(rest '(a))
14:34	clojurebot	()
14:34	andyfingerhut	,(coll? (rest '(a)))
14:34	clojurebot	true
14:34	andyfingerhut	,(next '(a))
14:34	clojurebot	nil
14:35	noonian	(empty? nil)
14:35	noonian	,(empty nil)
14:35	clojurebot	nil
14:35	noonian	,(empty? nil)
14:35	clojurebot	true
14:36	bolted	https://www.refheap.com/19451
14:36	bolted	So this stack overflows on both my tests, but I'm not totally sure this is what I originally had
14:37	andyfingerhut	It stack overflows because of the combination of rest and coll? behavior shown above.
14:37	bolted	Oh, (rest '()) is also a collection.
14:38	noonian	your if is poorly nested I think
14:38	andyfingerhut	It is common to use (seq xs) to determine when you reach the end, before testing anything about the first element.
14:38	noonian	it is returning (conj (first x) (my-flatten (rest x))) in all cases
14:39	bolted	,(seq '())
14:39	clojurebot	nil
14:39	andyfingerhut	i.e. try putting (if (seq xs) ...) around your current function.
14:39	andyfingerhut	er, your current function body
14:40	andyfingerhut	I'm not saying it will make the function completely correct, but it should eliminate the infinite regress
14:40	noonian	bolted: I think this is what you want, http://pastebin.com/iYSdWJgZ
14:41	noonian	bolted: you were closing your if on this line: (my-flatten (first x)) (my-flatten (rest x)))
14:41	noonian	and not concating them together
14:42	bolted	noonian: oh whaaaat. thank you, that's a silly mistake to make
14:43	bolted	andyfingerhut: You're right, it does eliminate the stack overflow
15:00	ruzu	i think the best thing about clojure ... is rich hickey's hair
15:04	rlb	So I think I am going to need to add some jni bits to a project -- is there a recommended way to handle that via lein, or would people tend to make it a separate java project?
15:05	TEttinger	I'm sorry, rlb.
15:05	TEttinger	there's also JNA if you want a bit less hassle and a bit less performance
15:06	TEttinger	https://github.com/Chouser/clojure-jna/ I think the readme is really outdated
15:07	rlb	TEttinger: right -- may end up being able to use jna, but I'd also like to know what if any recommendations people have for handling jni.
15:08	rlb	i.e. can it fit in with lein much at all, or should I just create artifact(s) via mvn/gradle/whatever.
15:08	rlb	etc.
15:08	TEttinger	http://www.paullegato.com/blog/jni-leiningen-native-path/ ?
15:10	sm0ke	llasram: there?
15:10	rlb	TEttinger: right, thanks -- I'd seen that, but if I read it correctly, that suggests a way to use existing jni jar/.so's with lein, but lein's not building them.
15:11	TEttinger	ah. JNI is confusing...
15:11	sm0ke	llasram: what do you think of using nippy in abracad for encoding and decoding binary data...its fater and more comprehensive
15:11	TEttinger	https://github.com/technomancy/leiningen/blob/master/sample.project.clj#L252 is a little more doc
15:11	TEttinger	what is nippy?
15:12	rlb	I'm guessing that the simplest thing would be to just build the artifacts separately, and then use that to access them from clojure, but I wasnted to check in case there was somethng I'd missed.
15:12	sm0ke	TEttinger: https://github.com/ptaoussanis/nippy
15:12	rlb	"wanted to check"
15:14	dav	user=> (def a '(+ 3 4)) ; -> #'user/a user=> (apply (first a) (rest a)) ; -> 4 ;; What's wrong?
15:15	gfredericks	dav: symbols are not functions
15:15	TEttinger	this is nice, sm0ke
15:16	gfredericks	well
15:16	gfredericks	actually they are
15:16	gfredericks	just not in the way you're expecting
15:16	riley526	Question: Is there a way to require and call a fn in a namespace inside of a let, given a string like "my.ns.whatever/func"? e.g. (let [myns (require-by-str "my.ns.whatever")] (call-fn-in-ns myns "func"))
15:16	gfredericks	,('+ '{= 12, + 14})
15:16	clojurebot	14
15:17	gfredericks	dav: ^
15:17	riley526	I don't know if that's a good example
15:17	dav	gfredericks: how is (3 4) = to { = 3, + 4 } though?
15:18	sm0ke	yea its pretty cool.. but i dont know about the awkward names nippy/thaw
15:18	gfredericks	riley526: (let [sym (read-string s), ns (-> sym namespace symbol)] (require ns) ((resolve sym) "some" "args"))
15:18	noonian	,(apply '+ '(3 4))
15:18	clojurebot	4
15:18	gfredericks	dav: it's not; I was trying to demonstrate what symbols do when you call them as functions
15:19	gfredericks	,(apply '+ '(3 4 5 6 7))
15:19	clojurebot	#<ArityException clojure.lang.ArityException: Wrong number of args (5) passed to: Symbol>
15:19	noonian	('+ 4)
15:19	dav	gfredericks: I understand I needed an eval now. But I don't understand why I got what I got..
15:19	noonian	,('+ 4)
15:19	clojurebot	nil
15:19	sm0ke	its cooler than saying nippy/deserialize though
15:19	noonian	('+ 4 5)
15:19	dav	gfredericks: it takes the second arg somehow?
15:19	noonian	,('+ 4 5)
15:19	clojurebot	5
15:19	noonian	what do symbols do when called as functions?
15:19	gfredericks	dav: the same reason you get ##(apply :+ ["foo" "bar"])
15:19	lazybot	⇒ "bar"
15:19	gfredericks	symbols do the same thing keywords do
15:19	noonian	ah
15:20	dav	gfredericks: k thanks. not exactly the most intuitive feature of the language imho..
15:20	gfredericks	right you are
15:20	gfredericks	probably not often used either
15:21	riley526	gfredericks: ah, interesting... resolve is like ns-resolve, but it resolves all the way down to the fn...
15:21	TEttinger	##(let [a [+ 3 4] b '(+ 3 4)] (str "vector: " (apply (first a) (rest a)) " list: " (apply (first b) (rest b))))
15:21	lazybot	⇒ "vector: 7 list: 4"
15:21	riley526	gfredericks: great help, thanks!
15:21	TEttinger	that would have bit me too/
15:22	gfredericks	riley526: unless you're working on some kind of tooling, I'd avoid that kind of stuff though
15:22	gfredericks	if possible
15:23	gfredericks	TEttinger: good example
15:23	riley526	gfredericks: well I'm just toying around with the idea of stuffing a str representation of a function into a db and calling it later with some args, like a task queue or something
15:23	TEttinger	thanks. I've got a similar question to riley526
15:24	pandeiro	riley526: what are the drawbacks/gotchas to that approach? i was wondering about something similar myself for serializing fns
15:24	srruby	I want to use a jar file from within clojure. Is there a simple way to do this without learning maven?
15:24	riley526	pandeiro: I honestly don't know, haha. Just exploring right now.
15:24	TEttinger	https://github.com/Prismatic/hiphip is wonderful but doesn't work with AOT. I have my own AOT fork that is a complete hack but works. I want to clean mine up a bit so it can get merged into Prismatic's version.
15:24	riley526	pandeiro: I would love to know of other ways of accomplishing something similar.
15:25	TEttinger	https://github.com/Prismatic/hiphip/issues/1#issuecomment-23361820
15:25	pandeiro	riley526: yeah on the surface it seems like a simple, effective way to do it
15:25	TEttinger	I don't get macros quite yet.
15:25	TEttinger	riley526 there's also metadata holding a string representation of the source.
15:26	pandeiro	i was looking at the code for Prismatic's dommy cljs lib and the use of macros really baffled me...
15:26	TEttinger	(there can also be metadata I mean)
15:26	riley526	TEttinger: in the defn of the fn itself?
15:27	riley526	I feel weird about storing actual source code to be run later
15:27	TEttinger	riley526, I bet that would be a good usage for a macro. defn+
15:29	TEttinger	riley526, I was thinking you could have defn+ that acts like defn but stores the macro body as a string in metadata
15:29	TEttinger	*but also
15:29	riley526	gfredericks: given my use case, is there a better approach you would recommend?
15:30	nDuff	TEttinger: Someone's done that, actually.
15:30	TEttinger	nDuff, the defn with source in the fn as meta?
15:30	TEttinger	or hiphip with AOT?
15:30	nDuff	TEttinger: https://github.com/technomancy/serializable-fn/
15:31	riley526	nDuff: oh cool
15:32	TEttinger	damn under 25 lines...
15:33	dublindan	If I have a collection like [[:a 1] [:b 2] [:a 3] [:a 4] [:b 5]], does anyone have any suggestions for an easy way to turn that into a map like: {:a [1 3 4] :b [2 5]} ?
15:34	noonian	,(into {} [[:a 1]])
15:34	clojurebot	{:a 1}
15:34	noonian	hmm
15:34	noonian	i'd use reduce
15:37	dublindan	yeah, playing with reduce now. Lemme see what I can do..
15:37	TEttinger	frequencies?
15:38	TEttinger	yeah, reduce.
15:38	dublindan	,(reduce (fn [m x] (assoc m (first x) (conj ((first x) m) (second x)))) {} [[:a 1] [:b 2] [:a 3] [:a 4] [:b 5]])
15:38	clojurebot	{:b (5 2), :a (4 3 1)}
15:39	dublindan	ok, that works
15:40	TEttinger	seems useful, what's it for?
15:42	dublindan	Grouping results from a database query
15:43	TEttinger	ah.
15:46	dav	is there any rationale for why bindings and arglist use vector syntax (brackets) rather than parens or something else?
15:47	TEttinger	yes.
15:47	TEttinger	it stands out more, and it allows slightly faster random access
15:48	dav	TEttinger: what do you mean random access? these are actually treated as vectors under the hood?
15:48	TEttinger	yes
15:48	TEttinger	as opposed to lists
15:48	dav	hmm ok
15:48	dav	thanks
15:52	gfredericks	I don't think random access has anything to do with it
15:53	gfredericks	they only exist at compile time
15:54	holo	i just thought about something "random", and can't find anything on the web: bindings for cobol..
15:55	holo	does it make sense?
15:55	gfredericks	I'm thinking it's impossible to create a lazy seq that has some given metadata in each tail without creating my own version of the LazySeq class
16:00	TEttinger	so, I'm trying to get w01fe's example to work...
16:01	TEttinger	(defmacro import-vars [ns] `(do ~@(for [[sym qual] (ns-map ns)] (read-string (clojure.repl/source-fn qual))))) ;; this is what I have now.
16:01	TEttinger	I have no idea what ~@ does
16:01	nDuff	TEttinger: inside `(), `@ is an unsplice
16:02	nDuff	TEttinger: ...see http://clojure.org/reader
16:02	nDuff	err, ~@
16:08	nDuff	,`(one two ~@(for [k [1 2 3]] (str "key-" k)))
16:08	clojurebot	(sandbox/one sandbox/two "key-1" "key-2" "key-3")
16:08	nDuff	TEttinger: ^^ does that make it clearer?
16:08	nDuff	TEttinger: ...compare to...
16:08	nDuff	,`(one two ~(for [k [1 2 3]] (str "key-" k)))
16:08	clojurebot	(sandbox/one sandbox/two ("key-1" "key-2" "key-3"))
16:09	TEttinger	uhhh yes I think
16:09	TEttinger	it puts the contents in the `() as opposed to nesting it
16:09	TEttinger	like apply
16:25	TEttinger	so, ns-interns returns a map of stuff like {lefts #'clojure.zip/lefts} . How do I get the var bit off of lefts, and only have the quoted qualified symbol?
16:26	noonian	,`map
16:26	clojurebot	clojure.core/map
16:26	noonian	,#'map
16:26	clojurebot	#'clojure.core/map
16:27	noonian	,(symbol #'map)
16:27	clojurebot	#<ClassCastException java.lang.ClassCastException: clojure.lang.Var cannot be cast to java.lang.String>
16:27	noonian	,@#'map
16:27	clojurebot	#<core$map clojure.core$map@1645bda>
16:27	noonian	what do you want the symbol for?
16:27	noonian	,(name #'map)
16:27	clojurebot	#<ClassCastException java.lang.ClassCastException: clojure.lang.Var cannot be cast to clojure.lang.Named>
16:28	TEttinger	it's really hard to explain. let me try to figure out where to start...
16:28	noonian	,(quote #'map)
16:28	clojurebot	(var map)
16:29	TEttinger	So hiphip is a lib by prismatic that works fine at runtime when JITed. but when you AOT it, it tries to load the same namespace more than once, for every type they have implemented array stuff for.
16:30	TEttinger	https://github.com/Prismatic/hiphip/tree/master/src/hiphip everything but array loads type-impl, and only one should be imported.
16:30	TEttinger	but compile gets all of them
16:30	TEttinger	so I need to find a way to import type-impl into the current ns, basically
16:32	TEttinger	https://github.com/Prismatic/hiphip/blob/master/src/hiphip/double.clj see how it uses load? I don't think you can load it more than once.
16:32	TEttinger	in different namespaces
16:33	bobwilliams	hello
16:33	noonian	hmm idk much about aot compile issues
16:33	bobwilliams	what is the correct way to handle the case where you are reducing and encounter a nil?
16:33	bobwilliams	user=> (reduce * [1 2 nil 4])
16:34	bobwilliams	for example
16:34	bobwilliams	right now i'm using a try / catch but not sure that's the best way
16:34	klrr_	is reduce like haskell's foldr?
16:34	noonian	threading macro and filter would be a nice way
16:34	noonian	(->> [1 2 nil 4] (filter identity) (reduce *))
16:34	noonian	,(->> [1 2 nil 4] (filter identity) (reduce *))
16:34	clojurebot	8
16:35	bobwilliams	awww
16:35	bobwilliams	good idea
16:35	noonian	or
16:35	noonian	,(reduce * (keep identity [1 2 nil 4])
16:35	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading>
16:35	noonian	,(reduce * (keep identity [1 2 nil 4]))
16:35	clojurebot	8
16:35	bobwilliams	perfect!
16:35	bobwilliams	thanks so much noonian!
16:35	noonian	you're welcome!
16:44	noonian	that will also filter out falses btw
16:45	dav	Is it possible to, at runtime, examine a function's "code" and substitute certain expressions in it for another expression? I just read up a bit on macros and it didn't seem that obvious..
16:45	bobwilliams	gilbertw1, TEttinger, noonian: thanks again! https://github.com/bobwilliams/project-euler/blob/master/clojure/problem-11.clj
16:47	TEttinger	yay
16:48	noonian	dav: macro expansion happens at compile time, so you could examine constants in the code (or symbols that are macros) and substitute them with other code
16:49	noonian	,(macroexpand or)
16:49	clojurebot	#<CompilerException java.lang.RuntimeException: Can't take value of a macro: #'clojure.core/or, compiling:(NO_SOURCE_PATH:0:0)>
16:49	noonian	,(macroexpand 'or)
16:49	clojurebot	or
16:49	noonian	,(macroexpand '(or true false))
16:49	clojurebot	(let* [or__3943__auto__ true] (if or__3943__auto__ or__3943__auto__ (clojure.core/or false)))
16:50	noonian	so at compile time (or true false) gets substituted by those let and if expressions
16:50	noonian	,(macroexpand '(or false))
16:50	clojurebot	false
16:51	noonian	,(macroexpand '(or (= false true) true))
16:51	clojurebot	(let* [or__3943__auto__ (= false true)] (if or__3943__auto__ or__3943__auto__ (clojure.core/or true)))
16:52	pepijndevos	Any mathy people around? I'm trying to compute the speed of the wheels of a car making a turn.
16:52	dav	alright let me give of an example of what i'm trying to do, let's say I'm writing a function that gets some values from a key/value database storage. And I want to programmatically "scan" the function for what it needs and fetch the values from the db PRIOR to running the code of the function.
16:53	dav	for instance (defn f [a b] (+ a b (dbValueGet "abc") (dbValueGet "def"))
16:53	dav	I'd like to "scan" for dbValueGets and get the values prior to evaluating f
16:53	dav	then I'd like to be able to "substitute" the values in once I decide to execute the code
16:54	dav	is that something that would be possible?
16:54	TEttinger	yes, I think
16:54	noonian	hmm, I don't really understand the use case
16:54	TEttinger	,(doc clojure.repl/source-fn)
16:54	clojurebot	"([x]); Returns a string of the source code for the given symbol, if it can find it. This requires that the symbol resolve to a Var defined in a namespace for which the .clj is in the classpath. Returns nil if it can't find the source. For most REPL usage, 'source' is more convenient. Example: (source-fn 'filter)"
16:55	noonian	but you could return say, a vector of the values, and another function which when called executes it with the values or something
16:56	noonian	(defn f [a b] (let [abc-val (dbValueGet "abc"), def-val (dbValueGet "def")] [[abc-val def-val] (fn [] (+ a b abc-val def-val))]))
16:57	dav	noonian: I want to avoid having to write every single function in my code base as a closure or something of that sort if possible.
16:58	dav	TEttinger: you mean I would actually have to parse the code myself rather than manipulate it as a list?
16:59	noonian	you could write a macro that does that pattern for you
16:59	dav	my understanding is that lisp code is just lists.. why can't I just manipulate it as such?
16:59	TEttinger	dav: I am not the person to ask.
16:59	TEttinger	I'm pretty sure you can use macros for this...
16:59	dav	noonian: can a macro take a function, transform it, and return another one?
16:59	TEttinger	yes
17:00	TEttinger	,(doc complement)
17:00	clojurebot	"([f]); Takes a fn f and returns a fn that takes the same arguments as f, has the same effects, if any, and returns the opposite truth value."
17:00	noonian	you would write a macro that expands into code that does that
17:00	dav	ok let me google a bit more on that you guys have given me a few buzz words to look for. thanks!
17:00	noonian	but you can write functions that do that also, and don't even need macros
17:01	pepijndevos	you could also write dbValueGet as a macro, that when provided with a literal value, expands into the value from the database.
17:01	dav	TEttinger: complement is just a trivial closure..
17:01	noonian	(defn complement [f] (fn [& args] (not (apply f args))))
17:01	TEttinger	yes.
17:01	TEttinger	but it does what you asked
17:02	TEttinger	...kinda
17:02	dav	TEttinger: it doesn't modify the inside of f, it only changes the result of f.
17:02	dav	pepijndevos: injecting the values can probably be done as you describe. what about scanning for the required database keys prior to running?
17:03	pepijndevos	what is the use case? Do you just want to get a list of all the keys?
17:05	dav	pepijndevos: that is one of the requirements
17:05	dav	pepijndevos: I think if you get me on the way of doing that, I can probably figure out how to do the rest..
17:06	dav	I was hoping for "ultimate flexibility" i.e. some function f is effectively a "list" and I would have loved to traverse it and manipulate it as such. I can't seem to find how to do that..
17:06	noonian	so, a macro is just a normal function whos return value is code
17:06	noonian	using defmacro instead of defn makes it run at compile time instead of runtime
17:07	noonian	but you can write functions that return code to, perhaps to be used from a macro
17:07	pepijndevos	(defmacro dbValueGet [key] (swap! all-keys conj key) `(dbValueGet* key))
17:07	pepijndevos	that way it should fill the atom by just loading all the code… maybe
17:08	noonian	idk if that would work using an atom like that at compile time
17:09	dav	ok you're using some concepts I'm not yet familiar with pepijndevos (swap! and `)
17:09	dav	assuming you define dbValueGet in this way
17:09	pepijndevos	alternatively you could just grep the code :D
17:09	dav	and f(a,b) in the way I did above
17:09	dav	how do you write a function that looks at f and spits out the keys ("abc", "def") ?
17:10	dav	maybe f needs to be a macro..
17:10	pepijndevos	you don't, dbValueGet will store them at macro-expansion time
17:10	dav	aaaaah.
17:10	noonian	yeah, I think you want f to be a macro
17:10	dav	cute.
17:10	pepijndevos	if it works...
17:11	dav	does it know "where it was called from" ?
17:11	dav	i.e. which function needs what keys
17:11	noonian	so, earlier when you said you don't want to have to write all your code with clojures
17:12	noonian	you can make a macro that in the background creates those clojures and returns the appropriate thing so its clean to use
17:12	noonian	sorry, closures* :p
17:13	pepijndevos	https://www.refheap.com/19455
17:14	dav	I guess if you guys have the patience and interest, I should tell you more about the usecase. The idea is to implement a spreadsheet (Excel) like computation graph.
17:14	dav	In a spreadsheet, cells depend on other cells output, and combine them with some function
17:15	pepijndevos	works! https://www.refheap.com/19456
17:15	dav	For instance, cell A1 could be "=A2*A3+A4"
17:15	dav	And not only you want to be able to evaluate the cells and compute their results, you want to be able to manipulate the computation graph as such, see who depends on what, etc.
17:15	dav	(without evaluating)(
17:17	dav	pepijndevos: very nice. now is there a way to know that "b" is used in foo?
17:17	pepijndevos	maybe… macros have some magic properties
17:20	pepijndevos	Does this math make any sense? https://www.refheap.com/19457
17:22	pepijndevos	I think the radius/trail functions are okay, but the ratio is not okay.
17:22	AimHere	What angle is the 'angle' here, for the radius/trail functions?
17:24	AimHere	Seems odd for symmetry reasons that the rear-wheel formula is X/tan when the front wheel formula is X/sin
17:28	dav	pepijndevos: ratio looks fine to me
17:29	pepijndevos	AimHere, it's the degrees that the fromt wheels are turned
17:31	pepijndevos	AimHere, If you draw a triangle between the wheelbase and the point where the front wheel "intersects" the rear wheel. The idea is that sin will give you the length of the long side of the triangle, wile tan gives you the straight side. Which should be the distance from the rear wheels to the intersection point. Maybe...
17:32	pepijndevos	I used this and some experimenataion: http://www.personal.psu.edu/njk909/turning_radius.JPG
17:32	pepijndevos	well, not really that. I just took the center of the two wheels.
17:33	pepijndevos	dav, at least I'm applying ratio twice now, which I don;t think is right...
17:33	dav	pepijndevos: are you at psu?
17:34	pepijndevos	psu?
17:34	dav	pepijndevos: http://www.personal.psu.edu/njk909/turning_radius.JPG
17:34	dav	pepijndevos: thought maybe this was your page..
17:34	pepijndevos	no, just googled that
17:34	dav	ok
17:35	pepijndevos	the trail function is supposed to give the length of the bottom line in that picture.
17:35	pepijndevos	I thought I might need to use that instead of radius, as the wheels are further inwards than the front wheels.
17:37	pepijndevos	But the speed difference for the wheels seems to be to large
18:00	tshauck	Hi, is there a good way to apply two different functions to a map... I have (def j '({:a "1", :b "2013-01-01"} {:a "2", :b "2013-01-01"})) I'd like apply a function f to all the :a's and a function g to all the :b's
18:05	llasram	tshauck: Like? ##(map (juxt (comp dec :a) (comp inc :b)) [{:a 1, :b 2} {:a 3, :b 4}])
18:05	lazybot	⇒ ([0 3] [2 5])
18:09	tshauck	llasram: ya, that seems to ahve the desired effect... I now just have to figure out what it does :)
18:09	tshauck	or i guess how it works
18:09	llasram	~juxt
18:09	clojurebot	if you think 'complement is great, wait till you see 'juxt
18:09	llasram	~juxt
18:09	clojurebot	juxt is usually the right answer
18:09	llasram	That's the one I was looking for :-)
18:13	tshauck	so, if I understand this, comp combines the getting of they key with function that's applied then juxt will "chain" those function across the map... does that sound right?
18:20	llasram	Kind of. comp is function composition and juxt is function juxtaposition
18:21	llasram	comp creates a function which chains together multiple function, connecting return values to arguments
18:22	llasram	juxt creates a function which "simultaneously" applies multiple functions to the same argument, returning a vector of the results
18:31	akurilin	Is it bad tone to inject namespaces like timbre, clj-time, c.t.t in all of my namespaces? I use them almost everywhere
18:32	akurilin	In project.clj, that is.
18:33	bordatoue	is there a way to iterate through more than one seq at a time, for example if I have [1 2 3] [4 5 6] [ 7 8 9] can I iterate through all the three seq and print [1,4,7] [2,5,8] [3,6,9]
18:35	llasram	bordatoue: `map` takes any number of seqs as arguments: ##(map vector [1 2 3] [4 5 6] [7 8 9])
18:35	lazybot	⇒ ([1 4 7] [2 5 8] [3 6 9])
18:36	llasram	akurilin: Yeah, that's not really common / never seen it. If you want some automation, https://github.com/technomancy/slamhound/ can help you
18:36	bordatoue	llasram: what if I want to replace the seq with reading a line for three different files can I accomplish it using map
18:37	llasram	bordatoue: `line-seq` turns a reader into a seq of lines. pass three of those to `map` and you read a line from each file for each `map`d function call
18:37	bordatoue	llasram: thanks, I guess it will work with any lazy-seq then
18:38	llasram	For the most part, all seqs are created equal
18:41	dobry-den	akurilin: I had a case where I wanted all files in a namespace to have the same set of :require'd namespaces and for now just wrote a macro that (require '...) various files
18:41	akurilin	dobry-den, llasram , cool, thanks for the advice
18:49	dav	TEttinger / noonian / pepijndevos - Seems like the backquote operator does exactly what I want? Turns code into a list and I can manipulate it and then evaluate it.. If you didn't mention it I assume it was because there's something wrong with it?
18:49	TEttinger	I don't know what backquote does, but you're probably right.
18:50	TEttinger	,(`(+ 1 2))
18:50	clojurebot	#<ClassCastException java.lang.ClassCastException: clojure.lang.Cons cannot be cast to clojure.lang.IFn>
18:50	nightfly	,`(+ 1 2)
18:50	clojurebot	(clojure.core/+ 1 2)
18:50	dav	super powerful no ?
18:50	nightfly	,(let [hello :moo] `(+ 1 ~hello))
18:50	clojurebot	(clojure.core/+ 1 :moo)
18:51	nightfly	yup, even better when writing macros
18:53	dav	does anyone have a sense of performance hit if most if my code is "backquoted", modified programmatically, and only then executed?
18:53	dav	I assume there's a one time code at macro-expansion time and then that's it?
18:53	dav	s/code/cost/
18:53	yedi	so I have a few clojure fns, that create my elasticsearch index. I'm working on an ansible playbook to set it up. how should I go about doing that? is there an easy way to make a standalone script/jar that i can jsut run along with my webapps uberjar?
18:53	yedi	i mean i'm sure it's possible, but i'm not sure what the best methodology would be
19:01	ToxicFrog	I have an xml-seq. I want to get all of its content, concatenated, without tags - basically, recursively take the content of the root node, replace all nodes in the content vector with their content, and then concatenate. This sounds like something zipper should be able to do. Yes/no?
19:02	dnolen	dav: sounds like a horrible idea, eval compiles, there is no interpretation :)
19:07	arrdem	dnolen: true, but you can do code generation and eval at runtime..
19:07	arrdem	dav: not that it's a good idea, but it can be done.
19:07	dnolen	arrdem: that is a good idea depending on the situtation
19:08	arrdem	dnolen: okay fair enough. I've yet to have to generate code that way, but I can imagine wanting to.
19:10	dnolen	arrdem: http://blog.getprismatic.com/blog/2013/5/1/graph-faster-abstractions-for-structured-computation
19:11	arrdem	dnolen: I mean... http://github.com/arrdem/sad
19:12	arrdem	dnolen: instaparse too... :D
19:15	dav	dnolen: OMG. Graph is pretty much what I was trying to implement!!
19:17	dav	dnolen: well maybe not exactly, but I'm trying to build a spreadsheet-style computation graph. I don't think I fully understand what Graph does.. but it seems like there are some similar ideas..
19:21	dav	"But eval isn't evil in Clojure--there's no heavyweight construction of a compiler, no risk of mis-interpreting strings, just the same machinery we use to write macros." => seems like I was right to turn to Clojure for what I'm trying to do.
19:24	carif	is there a way to get tab completion in the clojure repl? I'm using 1.5.1
19:27	AimHere	carif > well I'm using emacs + nrepl and hitting tab does some completioning for me, but I don't know which bit of the puzzle is doing the completion
19:27	technomancy	carif: should work with `lein repl` too
19:28	carif	technomancy, lein repl! just tried it, works, cool
19:28	carif	technomancy, ty
19:29	technomancy	sure
19:56	indigo	Weird, my REPL just crashed
20:20	dav	anyone uses vim fireplace? seems like it recompiles/reloads everything each time I Eval an expression. Isn't there a way to avoid that? it's slow..
20:22	llasram	dav: Have you launched a nREPL server (via `lein repl`) in another terminal first?
20:23	llasram	dav: IIRC, fireplace doesn't do that for you, and if it lacks an existing server to connect to, lanuches a new JVM to evaluate each form
20:23	dav	llasram: yes I have.
20:24	llasram	Oh well. I'm afraid there my ability to make suggestions ends
20:24	dav	llasram: but you're right, seems like this is what's going on
20:24	dav	llasram: maybe it's not talking to it somehow.
20:32	dav	looks like lein repl isn't creating a port file.. :(
20:33	llasram	Which version of Leiningen are you running? And which version of fireplace?
20:33	llasram	There was a change to the location of the port file somewhat recently
20:33	llasram	And just to double-check -- you are running Leiningen w/in a project, yes?
20:34	dav	llasram: lein 1.7.1-1ubuntu1
20:34	dav	llasram: and latest git of fireplac
20:34	dav	I don't see any port files in my whole project tree
20:35	llasram	Oh, yeah, that's an old old version of Leiningen
20:35	llasram	For doing development with Leiningen, I recommend following the instructions on https://github.com/technomancy/leiningen to install the most recent stable release
20:36	llasram	You'll find that much is broken if you aren't using a leiningen 2.x version
20:37	dav	argl
20:37	llasram	It's not bad
20:37	dav	I wish there was an ubuntu ppa
20:38	llasram	Nah. It's the same thing as how Leiningen itself downloads specific artifact versions from external Maven artifact repositories
20:38	llasram	You want to lock that stuff in packages for distribution
20:38	llasram	But for development, you want to use a specific release you manage, isolated from the operating system
20:40	dav	Downloading Leiningen to /home/david/.lein/self-installs/leiningen-2.3.3-standalone.jar now...
20:42	dav	alright I'm up and running
20:44	dav	llasram: works! Thanks for the help!!!
20:44	llasram	np! Glad it was so easy :-)
21:26	mullr	In some clojurescript code I'm working on, I'd like to see if I can use with-meta on a value. In regular clojure, this is simply (instance? clojure.lang.IObj value), since IObj is the home of with-meta. Clojurescript models this as the IWithMeta protocol, but since protocols aren't reified at runtime the instance test always returns false. Any ideas?
21:27	mullr	(and I just found the answer, after typing the question)
21:27	mullr	for posterity, that answer is to use satisfies?
22:15	dobry-den	Clojure101 question: Let's say you're processing a bunch of maps you get back from an API. like {:m 4, ...}. do you generally write one transformation that turns those maps into {:media-type :image, ...}.
22:16	dobry-den	Or do you write a (media-type _) function -- (media-type {:m 4 ...}) -> :image
22:18	llasram	ddima_: It depends?
22:18	llasram	er,
22:18	llasram	^^ dobry-den
22:19	dobry-den	What would it tend to depend on?
22:20	llasram	Any number of things. Your question is kind of vague :-). If an existing API worked in terms of the original {:m 4} maps, I'd do the latter. If writing an entirely new layer, might do the former
22:23	dobry-den	Yeah, this is my own layer. I'm wondering how to organize the code in my own domain. The two options that stand out are transformating the maps add soon as they come in or writing functions that operate on the original maps. and never transform the maps.
22:23	mullr	llasram: I agree, that's a good way to think of it. I've found it valuable to have a standard data representation within a component, and to expose said data to other parts of the system via functions like (media-type _)
22:24	dobry-den	In an OO language, I would write my own wrapper class. Message.new({:m 4, :usr "chuck"}).media_type ;=> :image
22:27	mullr	dorby-den: I don't think that way of thinking is entirely wrong. Encapsulating data access via functions lets you make decisions later on about how to do it
22:28	mullr	A layer of indirection solves all problems! But the same set of decisions apply as to whether you need it or not.
22:30	mullr	In clojure, people tend to lean towards sharing generic data (maps, etc), and thinking hard about what exactly that data should look like. This works because there's just a few core data structures that are really good. But there are times you want to encapsulate the access as well.
22:31	mullr	/diatribe
22:48	bitemyapp	akurilin: around?
22:49	akurilin	bitemyapp, sup
22:49	bitemyapp	akurilin: what improvements/changes to bulwark did we discuss?
22:50	bitemyapp	akurilin: I've got the email you sent, so there's at least a couple of things, but I wanted to make certain I'm aware of everything.
22:50	akurilin	Merging of map, overriding of 503 message, "work" variable name
22:51	bitemyapp	503 message I'm down with. Pretty sure I explained "work" to you. I could just document it better.
22:51	bitemyapp	akurilin: merging of map though?
22:52	akurilin	merge rather than or the config map
22:52	bitemyapp	Makes sense to me.
22:58	namccarty	Clojure is doing something to me that I don't understand, and that is making me scared. I can't figure out why it is throwing up an arity exception here: http://i.imgur.com/BSwJSgD.png
22:58	akurilin	bitemyapp, I was going to offer to PR but I'm completely swamped this weekend/week
22:58	bitemyapp	akurilin: it's already in my README and I'm charging ahead with it.
22:58	akurilin	okie dokie
22:58	bitemyapp	I'm generalizing the handlers into being part of the config.
22:58	bitemyapp	I just needed to know what was what.
22:59	namccarty	Anyone with more experience with me understand what is happening there?
22:59	namccarty	Or less experience, I don't discriminate
23:02	coventry	namccarty: Looks like the anon fn passed to reducing-and-map is being passed 1 arg when it expects 2.
23:02	llasram	namccarty: I don't know what `reducing-and-map` is, but it seems to expect a function of only 1 argument for it' first argument
23:03	coventry	namccarty: The error message is a little confusing, because it looks like it's talking about check-regions, when actually it's talking about check-regions$fn, the anon fn defined in it.
23:03	llasram	namccarty: The arity exception is for check-regions$fn, which means a fn defined w/in check-regions
23:04	llasram	coventry: jinx!
23:04	namccarty	coventry: Thanks, I just realized my mistake there, thought i was seeing an extra pair of square brackets and the error confused me
23:04	llasram	Geez
23:04	bitemyapp	has anybody here heard of a library called fusillade?
23:05	bitemyapp	I just found something by that name chilling out in my test cases and I'm not really sure where it came from.
23:05	llasram	namccarty: And BTW, using a text-based paste service like refheap.com is usually preferred to a screenshot
23:05	bitemyapp	...I think I wrote fusillade. n/m
23:05	akurilin	lol
23:05	llasram	bitemyapp: One of those days, huh?
23:05	coventry	namccarty: (require 'clojure.repl) (pst) would provide a more detailed stacktrace, which might have helped you see the problem faster.
23:06	namccarty	llasram: Thanks for clearing that up, I'm not used to clojures exceptions, I would have used pastebin or something, but my kde kept crashing when i tried to use my pastebin widget
23:06	bitemyapp	llasram: to my credit, I figured out it was my library because it had a good name.
23:06	bitemyapp	llasram: I just started coding for the evening (1933 here) and I'm a bit...fuzzy.
23:06	namccarty	coventry: thanks for the tip, ill have to remember that when my next confusing error pops up
23:06	bitemyapp	I'm also on a break from caffeine.
23:07	bitemyapp	ddellacosta: howdy
23:07	llasram	bitemyapp: Good luck with that. It's tough!
23:07	namccarty	also my kde kept crashing when i then decided to take a screen shot, i am mad at kde, but now my code works
23:07	namccarty	so no i am less mad
23:07	chare	i'm back
23:07	ddellacosta	bitemyapp: yo
23:09	bitemyapp	llasram: Thanks. I'm doing okay so far with tylenol, exercise, and sleep.
23:09	bitemyapp	paracetamol if you like.
23:18	bitemyapp	akurilin: bulwark 0.0.4 is on Clojars. * 0.0.4 Merging of config maps for partial overrides, overriding of condition handlers, documenting "work" variable name, updated clj-time to new API
23:18	bitemyapp	akurilin: is there anything you wanted for blackwater?
23:18	akurilin	bitemyapp, yay, thanks :)
23:18	bitemyapp	perhaps the "with-no-blackwater-logging" thingy?
23:18	akurilin	bitemyapp, you said that was better handled with robert hooke by the user,no?
23:19	akurilin	although I guess people would have to implement their own helper method
23:19	akurilin	over and over again
23:19	bitemyapp	akurilin: hum. I was making an immediate solution available and I would prefer users to understand that blackwater is ultimately just AOP via hooke, but a helper function is sensible.
23:22	bitemyapp	akurilin: there's also a sticky pattern that robert-hooke does not handle that users might find annoying that I could take care of in blackwater.
23:22	bitemyapp	namely, the with-hooks-disabled macro can only handle a single var at a time. The Korma stuff is a single var, but the JDBC stuff is not.
23:22	akurilin	ah
23:23	bitemyapp	this is kinda something I want anyway :)
23:23	bitemyapp	So you lucked out - I wanna fix this anyway before I go back to working on Simonides.
23:34	chare	lets talk about stupid stuff
23:34	chare	because we are all stupid
23:35	chare	that means you are stupid
23:37	coventry	chare: Since you like graphics programming, you should watch http://www.infoq.com/presentations/Clojure-LLVM Presenter gets 100-fold speed-up on computation of mandelbrot set by changing out his LLVM backend to target his GPU.
23:37	chare	coventry are you going to work on starcraft clone if i watch it
23:38	bitemyapp	technomancy: ^^
23:51	chare	I need to buy a new computer
23:51	chare	what parts do you recommend
23:53	bitemyapp	chare: this is #clojure - you should look into reddit for your needs.
23:54	chare	where in reddit
23:54	namccarty	r/buildapc is nice
23:55	right1	isn't intel's new cpu line coming out soon