#clojure – 2015-04-13

2015-04-13

00:06	Intensity	justin_smith: Hmm. Well the hash-map originally looks something like: {15 #{5 10}, 25 #{5}}, so it's a hash with sets as values. I provide the result of that map, where I still have the choice of "x" or "#{x}" there.
00:06	Intensity	Even when replacing conj with (fnil conj #{}), I still have the same issues.
00:09	justin_smith	,(reduce (fn [m [k v]] (update-in m [k] (fnil conj #{}) v)) {15 #{5 10} 25 #{5}} {1 3 5 7 25 42})
00:09	clojurebot	{15 #{5 10}, 25 #{5 42}, 1 #{3}, 5 #{7}}
00:09	justin_smith	oh wait, I can make that closer to your original, one moment
00:11	justin_smith	,,(reduce (fn [m [k v]] (update-in m [k] (fnil conj #{}) v)) {15 #{5 10} 25 #{5}} (map (juxt #(+ 5 %) identity) #{10 20 30}))
00:11	clojurebot	{15 #{5 10}, 25 #{20 5}, 35 #{30}}
00:12	Intensity	justin_smith: Cool, tahnks for the suggestions. Does my use of (partial merge-with [something] hash-map) have an intrinsic limitation? It seems I just want the keys of the hash (which are themselves sets) to merge as a union.
00:12	justin_smith	Intensity: merge-with won't ever alter keys that weren't present in the original
00:12	justin_smith	you need to update all keys
00:13	justin_smith	some are merged, the others become sets
00:14	justin_smith	the alternative would be to turn every value coming in into a set, unconditionally, then merge-with set/union I guess
00:14	justin_smith	but I think the reduce is simpler
00:18	Intensity	justin_smith: So it's that when I use merge-with, when the key didn't exist before, I have to pass in {10 #{5}}, but if the key did exist I have to pass in {10 5}? It does seem like reduce is simpler; I'm just trying to understand what you said about merge-with not altering keys not present in the original,
00:18	justin_smith	Intensity: merge-with only alters keys if they are present in two maps
00:18	justin_smith	all keys that are present in only one map, are unaltered
00:19	Intensity	since if I'm doing the overall (partial merge-with conj...) I get something almost like what I want, but I have to conditionally provide the value of the hash as a number or as a set with a number in it.
00:19	justin_smith	Intensity: the way to do it with merge-with would be to provide all vals in sets
00:19	justin_smith	and have set/union be the merge function
00:22	justin_smith	,(merge-with clojure.set/union {15 #{5 10} 25 #{5}} (into {} (map (juxt #(+ 5 %) hash-set) #{10 20 30})))
00:22	clojurebot	#error{:cause "clojure.set", :via [{:type clojure.lang.Compiler$CompilerException, :message "java.lang.ClassNotFoundException: clojure.set, compiling:(NO_SOURCE_PATH:0:0)", :at [clojure.lang.Compiler analyze "Compiler.java" 6535]} {:type java.lang.ClassNotFoundException, :message "clojure.set", :at [java.net.URLClassLoader$1 run "URLClassLoader.java" 366]}], :trace [[java.net.URLClassLoader$1 run ...
00:22	justin_smith	,(require 'clojure.set)
00:22	clojurebot	nil
00:22	justin_smith	,(merge-with clojure.set/union {15 #{5 10} 25 #{5}} (into {} (map (juxt #(+ 5 %) hash-set) #{10 20 30})))
00:22	clojurebot	{15 #{5 10}, 25 #{20 5}, 35 #{30}}
00:23	justin_smith	that does some work that the reduce based version doesn't have to do
00:23	justin_smith	creating an unneeded hash-map, and some unneeded hash-sets
00:23	Intensity	justin_smith: Thanks for the alternatives.
03:25	dysfun	is there transducers support for clojure 1.6 in a library?
03:26	cfleming	$mail sveri https://github.com/JetBrains/anko
03:26	lazybot	Message saved.
03:35	lxsameer_	guys, what is the RubyonRails of Clojure :)) ?
03:36	mpenet	dysfun: if you mean "as a library" I dont think so. core.async as partial support for transducers
03:37	mpenet	dysfun: but I doubt it's what you're asking for
03:38	dysfun	mpenet: no, it's not. damn. this waiting forever for clojure 1.7 thing is a bit tedious.
03:39	dysfun	lxsameer_: there isn't one, but there are a variety of frameworks with varying levels of guidance on building things
03:39	dysfun	i used to be quite fond of luminus
03:40	dysfun	they've changed it all recently though, i haven't tried the new one
03:40	dysfun	the commonly done thing is to pull in whatever libraries you need and roll your own framework as you go along
03:42	dysfun	some examples: url routing can be done with compojure, templating with selmer, sql database with korma
03:42	mavbozo	lxsameer_, hoplon and carribou are the closest
03:45	lxsameer_	thanks guys
03:50	chr15m1	lxsameer_: orthoganol to your question, but if i was going to implement something webby from scratch I think I'd write an HTTP API in pure Clojure with the UI as a separate project in Reagent on ClojureScript that talks to the API. Completely different architecture to you typical Ruby on Rails or Django project.
03:53	mavbozo	chr15m1, interesting, how do you handle SEO requirement? as far as i know, search engines still does not play nice with page generated by javascript in the browser.
03:53	chr15m1	mavbozo: yep, you are right. i am not sure there is a good solution. maybe a static-rendering pass in your build scripts.
03:53	chr15m1	mavbozo: maybe search engines need to get better. :)
03:55	lxsameer_	chr15m1: thanks
03:56	chr15m1	mavbozo: what we are doing is to look at what parts of our site need to be indexed and building those traditionally or as static HTML pages, and then the parts that are behind a login or otherwise not concerned with being indexed ("web app") we keep dynamic.
04:00	rriehle	chr15m1: on your orthogonal suggestion to chr15m1. You're spot on. I'm considering exactly that model for a Django project that will reach a tipping point at some point during its next release. Good to hear that others are thinking along the same lines.
04:00	mavbozo	chr15m1, i'm hoping approach such as this becomes mature https://github.com/pleasetrythisathome/om-server-rendering
04:00	mavbozo	basically, use nashorn js engine to render react in the server first
04:00	rriehle	s/chr15m1/xsameer_
04:01	mavbozo	so, the browser gets the react's fully rendered page, the js in the browser do the rest.
04:01	chr15m1	rriehle: we're using Django Rest Framework for the API.
04:02	chr15m1	mavbozo: that's awesome!
04:02	mavbozo	nice for user experience. no empty blank page.
04:03	rriehle	chr15m1: I'm thinking of that too. I've got some time before having to do any heavy reimplementation. I'm happy that Django is modular.. provides for several alternatives.
04:08	mavbozo	chr15m1, really awesome! we only need react rendering pipeline to generate user interface, either in browser or server. no additional infrastructure needed--just clojure and clojurescript (also java 1.8)
05:03	f3ew	`regex
05:04	f3ew	(help)
05:13	oddcully	,(doc re-matches)
05:13	clojurebot	"([re s]); Returns the match, if any, of string to pattern, using java.util.regex.Matcher.matches(). Uses re-groups to return the groups."
06:10	jonathanj	core.async doesn't really prescribe a way for communicating errors, does it? what are some common ways of communicating errors via channels?
06:12	mavbozo	jonathanj, i send exception inside a go block to a special channel
06:16	jonathanj	so you have a channel for data and a channel for errors?
06:17	mavbozo	jonathanj, yes
06:17	jonathanj	mavbozo: how do you relate errors in the error channel back to the data that caused them?
06:20	mavbozo	jonathanj, i use ex-info to create an exception info with additional specific data about where or what happens when those error occurs. then I put those exception info to the special error channel
06:25	jonathanj	mavbozo: nice, thanks
06:25	mavbozo	jonathanj, of course, there's another alternative to handle exceptions in go-block, like this, http://martintrojer.github.io/clojure/2014/03/09/working-with-coreasync-exceptions-in-go-blocks/
07:57	jonasen	Is there a reason core.async 'closed?' predicate is not exposed in the api (https://clojure.github.io/core.async/). It is part of the Channel protocol: https://github.com/clojure/core.async/blob/master/src/main/clojure/clojure/core/async/impl/protocols.clj#L23
08:48	justin_smith	jonasen: my first guess is that it is not a part of CSP
08:59	tdammers	sorry if this has been done to death, but what's the go-to parser-combinator lib?
09:02	jonasen	tdammers: parsers are often written with https://github.com/Engelberg/instaparse
09:03	tdammers	jonasen: I'll look into it
09:04	justin_smith	jonasen: to follow up a bit on the CSP point - there are rigorous proofs of some stuff in CSP, and I think the idea is to provide only the functionality csp does (plus some things composed from those building blocks)
09:04	hyPiRion	tdammers: https://github.com/cgrand/parsley for combinators. Instaparse isn't combinator I think.
09:04	tdammers	instaparse isn't combinator, no
09:05	tdammers	passing grammar as a string literal is a bit less elegant than what I'd like ideally, too, but I'm willing to accept that
09:05	tdammers	parsley looks cleaner at first glance
09:08	jonasen	justin_smith: thanks! I'm not that familiar with CSP core ideas
09:09	jonasen	other than both the reader and the writer blocks.. no one continues before the other is ready
09:11	oddcully	tdammers: you have seen the section about combinators at the instaparse GH page?
09:11	oddcully	tdammers: https://github.com/engelberg/instaparse#combinators
09:12	tdammers	oddcully: missed that part :D
09:12	oddcully	more options is never bad ;)
09:13	tdammers	true
09:20	jesus_couto	Is there any good clojure books/tutorials/videos to learn clojure as a programming beginner? Only did some basic tutorials on other languages and only know html and css. Thank you
09:21	martinklepsch	jesus_couto: maybe http://www.braveclojure.com
09:21	jesus_couto	I found this one http://clojurekoans.com/ but i am unsure if it is targeted to a beginner audience
09:21	martinklepsch	also potentially: https://aphyr.com/posts/301-clojure-from-the-ground-up-welcome
09:24	jesus_couto	martinklepsch: Thank you. Will check it now
09:46	sobel	my experience with learning clojure from brave/koans: good exercises if you need a nicely boxed problem to force you through lots of isolated pieces of learning. that method did not serve me. i only started learning once i committed to a small program of familiar type/complexity in clojure.
09:47	sobel	having a REPL to try little things as i integrated them into code was probably the biggest change to my usual coding style.
09:48	sobel	the next big change was length of code i can reliably write, without bugs. a proper coding session for me means figuring out about how much i can code between test/fix cycles.
09:48	oddcully	i just write them in the actual file and let them execute in the repl. yet the brave clojure were my first baby steps
09:48	oddcully	next was the cookbook on GH
09:49	sobel	...this channel is invaluable for semi-technical questions
09:50	oddcully	and my first "programs" where at codewars
10:44	virmundi	hello. Is this an apporpriate place to ask a question about the library hiccup?
10:48	justin_smith	virmundi: absolutely
10:49	virmundi	I need to add the defer and async attributes to a script tag. They are dangling attributes; they have no value. How can I do this?
10:49	justin_smith	virmundi: that's the equivalent of async="async"
10:51	virmundi	ok. did not know that. Thanks.
10:53	justin_smith	virmundi: this SO answer says async="
10:53	justin_smith	err
10:54	justin_smith	virmundi: this SO answer says async="" is more correct http://stackoverflow.com/a/23752239/2258453
10:54	sveri	cfleming: thanks for the link, looks interesting :-)
10:54	sveri	Anyone knows if I can inline view references to other vars in intellij without switchting the namespace?
10:55	virmundi	justin_smith: thanks
11:02	stompyj	Should clojurescript questions go here, or in #clojurescript?
11:03	bensu	stompyj: #clojurescript
11:03	stompyj	ty
11:05	m1dnight_	Guys, can anyone point me in the direction of where I can find how to create an anonymous class in Clojure?
11:05	m1dnight_	I'm trying to translate something from java to clojure but im stuck on the following:
11:06	m1dnight_	https://www.refheap.com/99554
11:06	noncom	m1dnight_: does not (proxy) work for that?
11:06	justin_smith	m1dnight_: reify and proxy both generate anonymous classes
11:07	justin_smith	proxy if you need to inherit something concrete, reify for interfaces
11:08	m1dnight_	Aha! Exactly what i needed. Thank you guys :)
11:24	engblom	I hope I am not breaking any rule by asking an offtopic question during the idle period: I wonder if anyone here knows about any general computer science channel?
11:25	sobel	engblom: i would try it here
11:25	sobel	CS is hardly off-topic here
11:25	justin_smith	engblom: there's #programming but that's a bit noisy
11:25	sobel	you'll get clojure-flavored answers most often, but..
11:26	noncom	how do i say "not nil" in prismatic schema?
11:27	engblom	I think a general cs channel would be better fitted as the answer might not include programming. Tomorrow I will get 1.5h with a bunch of elementary school kids. I would need a fun idea related to computer science that fits inside of just 1.5h.
11:28	justin_smith	engblom: you could play "robot" and see if they can describe simple tasks accurately enough for you to carry them out
11:28	justin_smith	this is probably better for younger kids
11:28	engblom	justin_smith: They are about 14 years old...
11:28	mpenet	noncom: you can use Object, or write a predicate (more readable)
11:28	sobel	something that exposes a deterministic behavior in something that usually seems like relative magic for kids comes to mind
11:28	justin_smith	engblom: that's not elementary school where I come from
11:29	sobel	engblom: expose something that is subject to common misunderstanding
11:29	sobel	14 is high school around here
11:29	engblom	Here around high school begins when you are 16.
11:30	engblom	sobel: Do you have any idea for a good misunderstanding?
11:30	sobel	engblom: probably not, and my cultural rooting is USA which doesn't necessarily translate to wherever you are
11:31	sobel	engblom: maybe you could tell a story about how computing has helped facilitate or solve a civil problem, or where significant technology is at the heart of something mundane
11:32	sobel	engblom: hope that helps
11:37	engblom	sobel: I think they would get bored.
11:38	engblom	A computer science quiz could maybe be one of the things to do. I appreciate if I get suggestion for questions
11:38	zerokarmaleft	engblom: if you're looking for something more kinetic, you could have kids carry out merge sort as a group
11:39	engblom	zerokarmaleft: Once I did something similar. They were even free to google for any sorting algoritm or inventing their own.
11:40	justin_smith	zerokarmaleft: even better, try various sorting algos, throw bogosort in there for comic relief http://en.wikipedia.org/wiki/Bogosort
11:40	zerokarmaleft	or whatever, the idea is that no matter how they start, the algorithm is stable and works every time
11:41	justin_smith	zerokarmaleft: I still think bogosort is amusing
11:42	zerokarmaleft	justin_smith: that would probably work with kids too...at least for a time :D
11:42	justin_smith	heh
11:42	justin_smith	"this is probably the stupidest possible way to get these playing cards in order - let's start making some better ways to do it"
11:43	zerokarmaleft	that idea btw is from simon peyton jones' work rejiggering the UK's primary education curriculum for computing
11:44	hoppfull	Hello. Clojure seems like an interesting language.
11:44	bensu	hoppfull: preaching to the choir. if you are just starting, write your impressions
11:45	hoppfull	bensu: It's an aweful experience so far. Not the language itself. But it's a massive hassle to even get it working.
11:45	bensu	hoppfull: ask for help here, we'll get you going.
11:45	hoppfull	bensu: I'm from python so maybe I'm a bit spoiled.
11:46	bensu	hoppfull: have you installed leiningen?
11:46	engblom	I was just going to ask the very same :)
11:47	engblom	Leiningen makes everything super easy
11:47	TEttinger	if you don't have a JDK it could be tricky I guess
11:48	hoppfull	I have. And It's fine. I stripped away a whole bunch of unecassary stuff from a starting project.
11:48	hoppfull	I can't help but feel as if I'm not doing it right.
11:48	engblom	hoppfull: What OS are you using?
11:48	hoppfull	But are we supposed to have a whole bunch of code and stuff just for managing our project?
11:49	hoppfull	Windows 8 I'm afraid.
11:49	bensu	hoppfull: for managing the project you have project.clj
11:49	bensu	hoppfull: ahhhh Windows...
11:49	bensu	hoppfull: it's hard
11:49	hoppfull	I know.
11:49	hoppfull	I like to develop on arch on my rpi but there doesn't seem to be any point in using clojure on rpi.
11:50	engblom	hoppfull: Why would it not be any point? There is even a gpio library for clojure.
11:50	hoppfull	Maybe I'm being silly but isn't the main reason we use clojure is to try to drag this industry, kicking and screaming into the next century?
11:51	zerokarmaleft	more or less
11:51	TEttinger	well for windows I can recommend the leiningen for windows installer
11:51	bensu	hopfull: that is one way to put it. the other one is that the point is to remove all "incidental complexity"
11:51	hoppfull	With other languages I like to develop on the rpi becouse it puts limits on me. But I feel that when I try to learn clojure, I should learn how to utilize it on modern hardware.
11:51	TEttinger	since lein downloads the clojure version you specify in project.clj if you don't have it
11:52	bensu	hopfull: clojure is not very lean and when the choice is between expressiveness and efficiency, it chooses expressiveness
11:53	hoppfull	Thank you all for your help! I'm sorry I was a little depressed when I came in here. I'm going to look into leiningen!
11:54	TEttinger	hoppfull, some gotchas I guess to initial dev: you should always have a project.clj . packages unfortunately need to comply with java stuff re:folder structure, there's a good walkthrough that gets linked a lot, I'll try to find it.
11:54	engblom	hoppfull: Clojure works well on rpi... but you need patience to load any clojure app. Once it is loaded, it is fast and good. On my rpi2, it takes 30s to reach REPL. On the older rpi it takes longer.
11:54	TEttinger	you don't need the test folder if lein generates it
11:55	sveri	hoppfull: I am using clojure in W8 without problems (besides one or two libraries that don't get the file locking right and test on linux)
11:55	TEttinger	a lot of dev can be done with just the REPL
11:55	TEttinger	lein repl
11:55	engblom	Once I wanted to quickly demonstrate a bit of clojure to a friend. Despite the leiningen installer for windows, I never got clojure to work on windows in that short time I had there.
11:56	klyed2	engblom: lol! Light table imo gets you up and running pretty fast
11:57	TEttinger	I primarily dev on windows, so I dunno what the problem is
11:57	sveri	engblom: I started a clojure course here at my office and had three guys with windows setup clojure and lighttable in like 15 minutes with download and everything (they had JDK installed already)
12:00	TEttinger	yeah if you were also setting up a dev environment for the first time period on windows, for any language, it could be tricky.
12:00	TEttinger	light table makes that easier
12:00	TEttinger	still need a JDK
12:02	arrdem	installing the JDK is hardly onerous tho
12:02	engblom	JRE is enough..
12:03	engblom	For windows, both JDK and JRE can be easily installed from ninite.com
12:03	engblom	The "difficult" part is setting the paths so you can run "java" directly from any directory
12:05	sveri	engblom: well, if that is regarded as difficult, uhm, its hard to argument against it :D
12:15	noncom	mpenet: oh, right
12:15	noncom	Object
12:15	noncom	ok
12:16	noncom	is anybody here fluent with neo4j cypher?
12:36	justin_smith	arrdem: just saw that you're flying out to clj/w - we should definitely get a drink while you're in town
12:37	arrdem	justin_smith: for sure!
12:41	pmonks	@noncom: I've done a bit with it, but I wouldn't say I'm "fluent".
12:44	pmonks	Supposedly there's a #neo4j channel on Freenode that might be a better place for cypher questions, but it looks empty.
12:45	pmonks	Oh never mind - I was just having trouble joining it - it's alive and well. ;-)
13:03	sdegutis	Is there a version of `for` that's analogous to `mapcat`, to replace the instances of (apply concat (for ...)) in my code?
13:04	matthava`	(defmacro forcat [[var seq] & body] `(apply concat (for [~var ~seq] ~@body)))
13:05	matthavard	maybe idk I just typed that out it might not work
13:07	sdegutis	That looks good. Why isn't it already in core?
13:14	crack_user	hello guys
13:18	justin_smith	hello
13:20	hiredman	for can already do concat
13:21	hiredman	(and it is better at it than applying concat)
13:21	hiredman	(for [var seq i var] i)
13:23	matthavard	Hmm that's nifty
13:24	matthava`	,(for [a [[1 2 3] [4 5 6] [7 8 9]]] a)
13:24	clojurebot	([1 2 3] [4 5 6] [7 8 9])
13:24	matthavard	,(for [a [[1 2 3] [4 5 6] [7 8 9]] i a] i)
13:24	clojurebot	(1 2 3 4 5 ...)
13:24	matthava`	noice
13:25	sdegutis	hiredman: very nice, thank you for that.
13:33	augustl	I have a bad habit of restarting my JVM when I make changes. Is this still the "de facto" reloaded workflow? http://thinkrelevance.com/blog/2013/06/04/clojure-workflow-reloaded
13:34	sdegutis	,(for [xs (partition 3 (range 1 10)) i xs] i)
13:35	clojurebot	(1 2 3 4 5 ...)
13:36	sveri	augustl: basically, yea. Also have a look at: https://github.com/stuartsierra/component If you are doing web development I put together a leiningen template which comes with components enabled and support for live reloading for cljs: https://github.com/sveri/closp you want to have a look on how to do it
13:38	augustl	sveri: tnx :)
13:39	augustl	I've tried something like that reloaded workflow, but my emacs seems to really act up if I get compilation errors so I ended up restarting the JVM anyway
13:39	bensu	augustl: are you using cider's latest version?
13:39	sveri	augustl: for this the reset functions works quite good
13:41	augustl	bensu: will investigate, tnx
13:42	bensu	augustl: I run cider 0.9.0 on ubuntu with a reloaded workflow and the only reason I have to restart is when I delete a multimethod.
13:43	augustl	is it possible to reload code so that old code is deleted, instead of just evaling the new code?
13:43	augustl	if only code was an immutable value in Clojure too? :)
14:13	noncom	i'll just leave it here: https://screeps.com
14:27	Vfe	lol@that link. I swear everytime I see something like that I just think of it like mechanical turk. Someone “gamified” a way to farm algorithim solutions.
14:29	Vfe	Maybe I should build my next enteprise app like that, make a game that’s a series of challenges just to get people to code the fastest solutions for me. String is all together and get a very fast program…that’s completely unmaintainable.
14:41	mavbozo	Vfe, Hey, you are the 'product'
14:43	sdegutis	Anyone have success using Boot instead of Leiningen for a simple web app with a test suite that needs to be uberjar'd for production?
14:43	sdegutis	(the app does, not the test suite)
16:12	ncthom91	hey all. Is it possible to use core.async channels to queue partially-applied functions?
16:13	ncthom91	i.e. (>! queue (partial f x y))
16:13	ncthom91	and then (let [f (<! queue)] (f))
16:24	jack0	Any idea about gsoc projects?
16:26	jack0	does anyone know which one might be selected?
16:27	amalloy	ncthom91: you can put any object into a queue. there's no reason it couldn't be a function
16:27	ncthom91	amalloy cool, thanks
16:29	jack0	??
16:29	lazybot	jack0: Definitely not.
16:29	clojurebot	? is suddenly
16:29	jack0	Not even which has possibility? lazybot ?
16:30	jack0	Sorry
16:39	bacon1989	I don't even know what the contenders are
16:52	TEttinger	$seen bbloom
16:52	lazybot	bbloom was last seen quittingQuit: Textual IRC Client: www.textualapp.com 1 day and 18 hours ago.
16:52	TEttinger	I just found his https://github.com/brandonbloom/eclj project, and I'm curious
17:26	dnolen	cfleming: does locals clearing work when debugging via the clojure.main REPL in Cursive?
17:27	cfleming	dnolen: You mean the button in the toolwindow? I'm not sure actually, possibly not - let me check
17:28	cfleming	dnolen: No, it doesn't work - currently it relies on a tooling connection, although I could change that. You'll just see the output of the command being executed.
17:29	dnolen	cfleming: can I just set the command line system property?
17:29	cfleming	dnolen: And I'd have to query it at startup, which the user would see too. I should go through all those buttons and disable the ones that don't work.
17:29	cfleming	dnolen: Yeah, you should be able to
17:30	m1dnight_	Guys, how can I write "(map #(true) '(1 2 3))" but then, you know, working?
17:31	m1dnight_	I think (map (fn [x] true) '(1 2 3)) is a little verboser
17:31	m1dnight_	but is it the only optoin?
17:31	cfleming	dnolen: I was actually thinking about putting a button in the debug toolwindow, that can actually use the debug expression evaluation and should work irrespective of the type of REPL
17:32	cfleming	m1dnight_: (map (constantly true) '(1 2 3))
17:32	cfleming	m1dnight_: Or just '(true true true) :)
17:33	m1dnight_	oh snap, I typed map. It has to be filter.
17:33	cfleming	m1dnight_: In that case the answer is '(1 2 3) :)
17:33	amalloy	m1dnight_: (filter (constantly true) xs) is just xs
17:33	m1dnight_	The context I'm using it in is (filter (if something #(true) predicate) list)
17:33	m1dnight_	okay thanks
17:33	m1dnight_	thats what I needed
17:33	m1dnight_	amalloy++
17:34	cfleming	m1dnight_: You'd be better of with (if something list (filter predicate list))
17:34	cfleming	s/of/off/
17:35	m1dnight_	valid point. I knew it could have been an XY problem, thats why I stated the context :)
17:35	m1dnight_	Thanks cfleming
17:35	cfleming	np
18:09	sdegutis	What's the latest and greatest way to write code thats both valid Clojure and ClojureScript?
18:09	amalloy	don't use any special forms other than (fn), and build everything back up from the lambda calculus
18:10	sdegutis	Even numbers?
18:11	amalloy	would alonzo church use numbers?
18:12	amalloy	man i dunno how to use cljs in real life, i am just making stuff up
18:12	sdegutis	I can't find it but someone did just that.
18:12	amalloy	$google coding with nothing ruby
18:12	lazybot	[Programming with Nothing] http://codon.com/programming-with-nothing
18:12	amalloy	someone ported it to clojure as well
18:12	sdegutis	YES THAT
18:15	sdegutis	THAT IS SO COOL.
18:18	sobel	practical, too
18:19	sdegutis	Is.. is this just Haskell?
19:04	daviid`	hello
19:05	daviid`	i understand i'm going to ask about something probably caused by imagej more then clojure itself, but in case a clojure pro spot the problem, that be nice
19:06	daviid`	here is a code and an explanation of my side effect problem: http://paste.lisp.org/+35G5
19:33	justin_smith	daviid`: I can't see how that println would change anything with that code
19:36	amalloy	justin_smith: it realizes the elements of results before entering the loop
19:36	daviid`	justin_smith: [so many justin that my emacs does not complete your name, too nad!] i think it is a side effect, terrible side effect from imagej, which reuses its resultstable, how bad is that?? but even knowing, i can't get it tight
19:37	daviid`	i narrowed down a bit, let me paste a new version
19:38	justin_smith	amalloy: yeah, you are right, it's that for loop in get-bounding-boxes
19:38	justin_smith	*for comprehension
19:38	justin_smith	(dec justin_smith) ; for calling it a loop
19:38	lazybot	You can't adjust your own karma.
19:41	daviid`	here: http://paste.lisp.org/+35G5 (1) renmed write-pp-... to save-hematite, (2) i have to scrap that portion of the initial image, doing it here instead of within the save-hematite procedure, better I think, and (3) the side effect is indeed get-max-area [which has to do some measure, hence reuse the resultstable...
19:42	daviid`	the above pasted code fails with the following exception:
19:44	daviid`	http://paste.lisp.org/+35G5/4
19:45	daviid`	[ i manally entered some \n to help you reading it of course
19:47	daviid`	so it processes partclies > 48 [the side of the bouding box], and does so for 0, 7, 14, 19, 27, 30 then crashes with this message "Column not defined: 11" which i don't understand: how could it work for some and not for others ?
19:47	daviid`	anyway, all due to this unique and reused results table from imagej of course
19:51	daviid`	there is no #imagej irc and #fiji-devel does not answer [till now]
19:52	daviid`	get-max-area semmes good to me, but you see it does not even clear its results -> 0 9057.0 7 9057.0 ... it always return the sme value ...
19:52	daviid`	oh well
19:53	sdegutis	Is there an alternative to Leiningen-profiles that's much less confusing and complicated?
19:54	TEttinger	apparently boot is getting usable? I haven't tried it
19:55	justin_smith	daviid`: as amalloy points out, for is lazy, and the timing of when you consume those results is going to change things, right?
19:55	TEttinger	http://boot-clj.com/
19:56	justin_smith	TEttinger: I have it in my yaks to shave queue, along with cider with debugging support, and setting up the mac I'll likely be getting from my new job
19:56	daviid`	justin_smith: what shoud i do ? instead of for ?
19:56	daviid`	timing will change of course, they reuse the same table
19:56	justin_smith	daviid`: you could put a doall around it to force eager evaluation
19:57	TEttinger	doseq is meant for side effects in the first place
19:57	justin_smith	TEttinger: he uses the results though
19:57	TEttinger	ah ok
19:57	justin_smith	TEttinger: just not fast enough for correctness yet
19:57	TEttinger	I just got here
19:58	daviid`	i use doseq instead of for right ?
19:59	TEttinger	doseq discards results
19:59	TEttinger	doall is correct here
19:59	daviid`	(doall (for ... ?
19:59	TEttinger	yes
19:59	TEttinger	(doc doall)
19:59	daviid`	let me try, tx
19:59	clojurebot	"([coll] [n coll]); When lazy sequences are produced via functions that have side effects, any effects other than those needed to produce the first element in the seq do not occur until the seq is consumed. doall can be used to force any effects. Walks through the successive nexts of the seq, retains the head and returns it, thus causing the entire seq to reside in memory at one time."
20:06	justin_smith	look at that, the doc string even mentions excactly why it should be used in this case
20:09	daviid`	justin_smith: TEttinger, tx, i just did not expect for to behave in a different way then it does in scheme [for-each], my mistake
20:09	daviid`	it works fine now, many thanks
20:09	TEttinger	ah great!
20:09	TEttinger	(inc justin_pdx)
20:09	lazybot	⇒ 1
20:09	TEttinger	(inc justin_smith)
20:09	lazybot	⇒ 238
20:09	TEttinger	karma shotgun
20:10	justin_smith	haha
20:10	justin_smith	TEttinger: collateral karma
20:10	TEttinger	yep
20:20	justin_smith	,(apply + (take Double/Nan (repeat Math/PI)))
20:20	clojurebot	#error{:cause "Unable to find static field: Nan in class java.lang.Double", :via [{:type clojure.lang.Compiler$CompilerException, :message "java.lang.RuntimeException: Unable to find static field: Nan in class java.lang.Double, compiling:(NO_SOURCE_PATH:0:0)", :at [clojure.lang.Compiler analyze "Compiler.java" 6535]} {:type java.lang.RuntimeException, :message "Unable to find static field: Nan in ...
20:21	justin_smith	,(apply + (take Double/NaN (repeat Math/PI)))
20:21	clojurebot	0
20:21	amalloy	take Double/NaN...you're a brave man
20:46	sdegutis	TEttinger: I looked into Boot and it looks like it might be simpler, but it seems to require a pretty seem knowledge of the JVM that I don't yet have.
21:05	haywood	Does anyone know how one would go about connecting this clojurescript node.js repl https://github.com/clojure/clojurescript/wiki/Quick-Start#nodejs-repl to emacs/cider?
23:23	PURE_TASTE	So I have a function of the form (map + c1 c2 c3 & colls), where all the colls are LazySeqs. It isn't working. I tried wrapping it in doall. Do I need to map doall?
23:27	PURE_TASTE	(map (doall (+ %&)) c1 c2 c3 & colls)
23:27	PURE_TASTE	Something like that except %& is not correct.
23:32	amalloy	do you want (apply map coll c1 c2 c3 colls)?
23:32	amalloy	it's not clear because you haven't explained what you want to do, just some wrong attempt, but that would be a reasonable thing to do
23:35	PURE_TASTE	results (map (fn [& bits] (apply + bits)) padded-xor-lists)
23:35	PURE_TASTE	results (map (fn [& bits] (apply + bits)) padded-xor-lists)
23:35	PURE_TASTE	results (map (fn [& bits] (apply + bits)) padded-xor-lists)
23:35	PURE_TASTE	results (map (fn [& bits] (apply + bits)) padded-xor-lists)
23:35	PURE_TASTE	results (map (fn [& bits] (apply + bits)) padded-xor-lists)
23:35	PURE_TASTE	results (map (fn [& bits] (apply + bits)) padded-xor-lists)
23:35	PURE_TASTE	results (map (fn [& bits] (apply + bits)) padded-xor-lists)
23:35	PURE_TASTE	results (map (fn [& bits] (apply + bits)) padded-xor-lists)
23:35	PURE_TASTE	results (map (fn [& bits] (apply + bits)) padded-xor-lists)
23:35	PURE_TASTE	So I want to produce a new seq from a collection of seqs where each entry of the new seq is the sum of all of the corresponding entries from the collection.
23:36	PURE_TASTE	Ah, I didn't mean to send that all. I'm using a webclient and was wondering why my pastes weren't working--they are.
23:37	PURE_TASTE	,(map + [1 2 3] [3 4 5] [5 1 2])
23:37	clojurebot	(9 7 10)
23:37	PURE_TASTE	So that works well enough. However, it doesn't work when instead of vectors I have lazyseqs.
23:37	PURE_TASTE	So I'm trying to figure that out and thought doall would be the way to go.
23:39	PURE_TASTE	Ah, shoot amalloy. I think I do need to use apply in this case. That's probably what was going wrong.
23:39	PURE_TASTE	amalloy: thanks for catching my mistake.