#clojure – 2010-12-07

2010-12-07

00:13	coldhead	definitely a place for both, cky, but very little room for "here is 10000 lines of code i wrote all by myself, please make it better"
00:14	coldhead	not that i'm bitter :)
04:04	kjeldahl	I want to like "cake", but there's always some issue about it. I've cloned it and symlinked bin/cake, and it makes a fuzz about missing classlojure . Any clues?
04:18	hiredman	kjeldahl: no reason you have to like or use cake
04:18	kjeldahl	hiredman: Well, it's a lot faster.
04:20	kjeldahl	And if a thing is supposed to work, I like to get it working before deciding. But you're right, if lein works and cake doesn't, it's a simple choice.
04:21	kjeldahl	Thing is, it's working great on one computer, but not the other. Just trying to piece the puzzle together.
04:34	kjeldahl	He he, how's that for a dependency.. Cake works, but only after running "lein deps" in it's source directory. It should probably ship with the required dependencies to make it runnable...
04:39	kjeldahl	Logged it as an issue: https://github.com/ninjudd/cake/issues/#issue/85
05:41	harishtella	(clojure + vim + unix) makes me feel like god
05:45	bobo_	required joke: then imageine how you would feel if you used emacs
05:56	bartj	how do I download a jar version from http://clojars.org/clj-json
05:57	bartj	I am unable to build it on my machine
05:58	kjeldahl	bartj: List it as a dependency in project.clj (assuming you use lein/cake)?
05:58	bartj	kjeldahl, we have not yet migrated to lein/cake, etc
05:59	kjeldahl	bartj: http://clojars.org/repo/clj-json/clj-json/0.3.1/clj-json-0.3.1.jar
06:04	bartj	kjeldahl, thanks! how on earth did you get that jar?
06:04	kjeldahl	On the front page of clojars.org, select "browse the repository". You're welcome!
06:12	bartj	has anybody built clj-json and used it before?
06:16	LauJensen	kjeldahl: Cake is fantastic and you get great support in #cake.clj from among other ninjudd who has written the majority of the code in it
06:29	Lajla	bartj, are you Dutch too?
06:31	AWizzArd	Any Swing expert here? JTables...
06:33	kjeldahl	LauJensen: Yeah, I figured it must have something since the pros use it. Installing from git however, does not work "out of the box". It needs more stuff, which it does not fetch on it's own.
06:34	LauJensen	kjeldahl: You're supposed to install via gems, to get the latest stable
06:34	bartj	Lajla, no
06:34	kjeldahl	LauJensen: Not according to the docs. git clone is supposed to work as well. But the docs may be wrong.
06:35	LauJensen	kjeldahl: Maybe Im the one who needs an update. Ive used it both in nix and windows via the gem installer/upgrader and it has always worked
06:35	bartj	I remember Lau recommending me to use clj-json
06:35	LauJensen	bartj: Was it good advice?
06:36	LauJensen	Hmm... Actually, it must have been because you were using a greater evil, because normally I would never recommend JSON
06:36	kjeldahl	LauJensen: Maybe ;-) For me, not having to mess with Ruby is another pluss (my background is with perl...).
06:36	LauJensen	kjeldahl: You dont have to mess with anything
06:36	kjeldahl	LauJensen: You're assuming ruby and rubygems is already installed on all systems?
06:36	LauJensen	For me it was "sudo pacman -S ruby && sudo gems install cake"
06:36	LauJensen	kjeldahl: no
06:37	kjeldahl	Doesn't pacman install ruby?
06:38	kjeldahl	It's not that I'm not able to install ruby and rubygems (apt-get install in my case), but it seems a bit overkill for installing dependencies for a tool which is supposed to help me manage dependencies.. ;-)
06:38	bartj	LauJensen, I am yet to find out
06:38	bartj	the sad part is that clj-json just doesn't cleanly compile :(
06:41	bartj	I just want to read json strings lazily
06:41	bartj	perhaps, I am being too lazy
06:54	fliebel	morning
07:01	LauJensen	kjeldahl: pacman would install ruby yes, so you should use apt-get. Where lein uses bash, cake uses a little bit of Ruby. It makes sense to use the deployment tools already available for that language
07:03	raek	,(fn descriptive-name [x y] (+ x y))
07:03	clojurebot	#<sandbox$eval462$descriptive_name__463 sandbox$eval462$descriptive_name__463@176343e>
07:04	Lajla	Because your name reminds me of raep
07:06	kjeldahl	LauJensen: Yes, I get how it works (now at least). I still think it's wierd. I got the impression that cake could be installed any way suggested on the homepage, but since it isn't "self bootstrapping" that's not really true. Bash is also a dependency, ok, but still more widely available than ruby. Compared to leiningen, which "just works" in more cases...
07:07	LauJensen	kjeldahl: Not if you're on Windows. But anyway, state your case in #cake.clj or raise it as an issue on github please
07:07	raek	or Solaris :)
07:07	kjeldahl	LauJensen: Anyway, I contributed a ticket at least on github. I guess the easiest solution is to state that additional packages are needed if not installed by ruby gems or similar.
07:11	raek	have fun.
07:12	Lajla	raek, that's what SHE said.
07:59	AWizzArd	Which pros/cons does definterface vs defprotocol offer?
08:06	cemerick	They both generate an interface, the latter is a protocol. :-P
08:08	fogus`away	definterface allows primitive args and rets
08:21	AWizzArd	Primitives are nice, good.
08:22	AWizzArd	I have a function that generates and returns a proxy. How do I typehint instances of it?
08:26	Chousuke	AWizzArd: Typehint it as whatever interfaces the proxy implements.
08:28	AWizzArd	Chousuke: ah good, so I can simply use this 90-char type-hint :)
08:30	AWizzArd	Chousuke: unfortunately it seems that a potentially random number is attached to the type name: my.projects.namespace.module.proxy$javax.swing.table.AbstractTableModel$TabelModelHelper$bb684924
08:34	bsteuber	AWizzArd: guess proxy internally uses sth. like gensym - but you shouldn't need the name
08:40	AWizzArd	bsteuber: do you have an idea how I can type-hint my proxies in a way that will be stable through restarts of a jvm?
08:41	AWizzArd	When rhickey joins I will ask him if it could make sense to extend 'proxy' taking a type-designator T, so that hinting can be done via: ^T my-proxy
08:41	Chousuke	AWizzArd: You shouldn't typehint the proxy by its class; that's frafile.
08:42	Chousuke	fragile
08:42	Chousuke	AWizzArd: what you want to do is typehint the proxy as whatever its superclass is
08:42	Chousuke	so if you proxy FooClass, Typehint the proxy as FooClass
08:43	AWizzArd	Chousuke: that unfortunately does not work they way I did it. My proxy proxies an AbstractTableModel. That is a class, implementing TableModel. It does not offer a method to delete all rows from a table.
08:43	bsteuber	AWizzArd: yeah just typehint it as AbstractTableModel
08:43	AWizzArd	So I added a definterface that defines 3-4 methods that are useful. My proxy also implements that interface.
08:43	bsteuber	ah
08:43	Chousuke	then you can typehint it as that interface.
08:43	AWizzArd	When I now say: (.clearTable ^AbstractTableModel my-table-model-proxy) <-- it can't find the right thing.
08:44	AWizzArd	Yes, I currently do this, and type-hint it as the interface. But in Java or with defrecords this would not be required.
08:44	AWizzArd	I can type-hint instances as designated.
08:44	bsteuber	why do you need a type hint anyways?
08:44	Chousuke	neither java nor defrecord can redefine methods on the fly.
08:45	Chousuke	proxy works as it was designed, not having access to its classname for typehinting is a feature :)
08:45	AWizzArd	bsteuber: to remove the type-hint warning that Clojure generates for me. My question in general is the other way around: why not type-hint everything?
08:46	AWizzArd	Chousuke: in Java the way would be to have class MyTableModel extends AbstractTableModel { ... }
08:46	AWizzArd	And in MyTableModel I could simply define 3-4 helper methods.
08:46	Chousuke	AWizzArd: yes, and that's nowhere as dynamic as proxy is
08:46	Chousuke	+near :P
08:46	Chousuke	any changes require a recompile
08:47	Chousuke	basically you're asking proxy to do things it wasn't designed for
08:47	AWizzArd	Chousuke: can you give me an example of what you mean by 'dynamic'?
08:47	bsteuber	AWizzArd: change a method on the fly
08:47	Chousuke	AWizzArd: you can replace proxy methods with a new implementation at runtime, without having to touch existing code in any way.
08:47	AWizzArd	Chousuke: there is no other lightweight way in Clojure to do this, as defrecord and deftype and reify can only take interfaces, but AbstractTableModel is a class unfortunately.
08:47	fogus`	Someone is wrong on the Internet!
08:48	Chousuke	AWizzArd: Then you need to use gen-class
08:48	AWizzArd	bsteuber: would that not be possible with an anon class in Java too?
08:48	AWizzArd	Chousuke: yes, though this is not very lightweight anymore. More chatty syntax.
08:48	Chousuke	then write a macro :P
08:49	bsteuber	AWizzArd: can you change a method of an existing anonymous class? I don't think so
08:49	AWizzArd	Ideal would be a defrecord that could also take classes, or even more ideal: not one single Java class implements any method on its own, but always from interfaces. Then defrecord would always work. :)
08:50	AWizzArd	bsteuber: I currently don't see an application for that. But it may be very well much more chatty in Java to do this (via Bytecode generation shrugs).
08:50	Chousuke	I think defrecord allowing classes would break the data/behaviour separation.
08:50	AWizzArd	yes
08:50	Chousuke	so it's out of the question :)
08:50	AWizzArd	Yes
08:50	AWizzArd	It makes sense the way it is.
08:51	AWizzArd	Only that it not operates well with the VM Clojure is running in.
08:51	Chousuke	I don't see a problem
08:51	AWizzArd	Because Sun chose to add methods to classes that do not come from Interfaces.
08:51	Chousuke	Good java APIs are based on interfaces anyway
08:51	Chousuke	there are bad ones, but you just have to accept that.
08:51	AWizzArd	But many Java APIs are not good ;)
08:52	Chousuke	yeah, and in those cases, just use gen-class :P
08:52	AWizzArd	Although this does not in its current version allow me to add fields as in defrecords?
08:52	AWizzArd	I can only have a :state which would be an atom or ref, which is way less performant when accessed.
08:53	Chousuke	it can also be a plain old mutable java object.
08:53	AWizzArd	Chousuke: does defclass allow multiple slots or only one :state slot? I am not sure what the current state of it is.
08:54	Chousuke	I've no idea, I've never actually used it :P
08:54	AWizzArd	Interesting it would be if defclass worked like defrecord in that aspect.
08:59	cemerick	AWizzArd: defrecord and deftype are not intended to be fully-featured interop constructs
09:00	AWizzArd	And this makes sense.
09:00	AWizzArd	They are serving a great purpose.
09:00	AWizzArd	It is just the design of the main VM Clojure is currently running on which can cause sometimes a bit pain, which would go away if defrecord/deftype actually allowed to extend a class.
09:01	AWizzArd	cemerick: a better solution would be that all methods that any Java class defines in all cases would be an interface method.
09:01	cemerick	Right; well, that ship has sailed. :-)
09:02	AWizzArd	This would of course bring tons of one-method interfaces into the game, but this would reflect the design style that Rich found to be better, and which he now implemented in Clojure.
09:02	AWizzArd	defrecords are just classes providing slots, with all methods coming from interfaces (protocolls). Sun however didn't.
09:03	AWizzArd	So, when implementing ones own TableModel one has to chose: AbstractTableModel+proxy or TableModel+defrecord. The latter will require more work, as nothing would be implemented, as in the AbstractTableModel case.
09:06	cemerick	AWizzArd: why is the proxy route insufficient?
09:07	jcromartie	what's the best way to manage 3rd-party jars that can't be added to clojars for licensing reasons?
09:11	cemerick	jcromartie: ideally, have your own nexus or artifactory instance
09:11	jcromartie	I used http://maven.apache.org/plugins/maven-install-plugin/usage.html for a temp fix
09:11	jcromartie	but yeah
09:13	neotyk	Has anyone working version of slime-who-calls?
09:20	Raynes	fliebel: Seems to be fine.
09:21	fliebel	Raynes: Huh?
09:21	Raynes	fliebel: The blog.
09:21	Raynes	fliebel: I just checked and it's still up.
09:22	fliebel	Raynes: It's a http://www.acidrayne.net/ right?
09:22	fliebel	Safari can't find the server
09:22	Raynes	No.
09:22	Raynes	http://blog.raynes.me
09:22	Lajla	Using a mac counts as admission to flaming homosexuality under US law.
09:22	fliebel	Raynes: Then update your github and twitter page ;)
09:26	fliebel	Raynes: Wordpress, eh? Also, page_id=2 (a.k.a. About) is rather terse compared to the huge posts you write.
09:27	Raynes	What would you prefer I use over wordpress?
09:28	fliebel	Wordpress is great, but something in Clojure would be nice, I guess. :D And if you must use WP, I recommend at least turning on permalinks ;)
09:29	Raynes	I don't really have any inclination to roll a blog in Clojure that wouldn't be even 10% as impressive as a default wordpress blog.
09:29	bobo_	Raynes: steal Lausjensens blogstuff?
09:29	fliebel	Agreed.
09:30	Raynes	I'd rather not.
09:30	Raynes	I actually don't mind wordpress.
09:30	pppaul	it's a blog, what's the big deal about what it runs under/
09:30	bobo_	i like the github stuff. because im lazy and it jsut worked
09:31	jcromartie	I cheated https://gist.github.com/731839
09:31	pppaul	unless you want to extend it...
09:31	Raynes	I'm in the process of writing a Clojure interface to wordpress and eventually various other engines and after that a desktop blogging client, so I have a reason to stay with Wordpress for now.
09:31	pppaul	sounds good
09:32	fliebel	Raynes: Wordpress is totally cool, but taking the time to configure and customize it does show of ;) You know how to do permalinks?
09:32	Raynes	No, because I never cared about permalinks. I'm very good at google.
09:33	fliebel	Raynes: You prefer ?p=48 over /some-nice-title/?
09:33	Raynes	It's shorter, more twitter-friendly.
09:34	fliebel	Raynes: You can get wp.me urls for every single page.
09:34	Raynes	I don't have to without permalinks.
09:37	fliebel	Raynes: Well, I like the fact that you do it as a consideration rather than just neglecting it. (You know you can set a custom permalink under the title field? so you can have /sexpbot/)
09:38	Raynes	Indeed.
09:40	AWizzArd	bsteuber and Chousuke: I just noticed that when my proxy proxies a class C and an interface I then for instances P of my proxy I can not ^C P or ^I P. So, type-hinting just won't work for such proxies it seems.
09:40	fliebel	Raynes: I just can't stand it thoug… hmmm, do you realize /48/ would be even shorter and more stylish?
09:41	jcromartie	fliebel: only ubergeeks and marketing people care about URLs
09:41	fliebel	jcromartie: Count me under geeks
09:41	jcromartie	fliebel: although Raynes' audience is ubergeeks
09:41	Raynes	fliebel: Well, nobody is forcing you to read it.
09:42	Lajla	fliebel, now you have admitted your famling homosexuality.
09:42	Lajla	Now what?
09:42	Lajla	Admit it, you support Assange
09:42	Lajla	in his crimes against the freedom of the US
09:44	fliebel	Lajla: Any interesting Clojure gotchas recently? ;)
09:44	Lajla	fliebel, you should know by now that I would never sell my soul to the darkside of lack of TCO.
09:46	fliebel	Lajla: Total Cost of Ownership?
09:47	Lajla	fliebel, tail call optimization
10:03	garytr25	hmm, wouldn't you rather know when tail call is happening explicitly?
10:05	lyonscf	Hey guys
10:06	edw	garytr25: No. As someone who comes from a Scheme background, Clojure's (understandable) lack of TCO is like dealing with someone you love believing in astrology.
10:07	garytr25	you should love them for who they are, not who you want them to be :-)
10:08	edw	Right, that's why I really like Clojure, but I'll like her a lot more when she quits smoking.
10:09	lyonscf	What's the best way to traverse a map?
10:09	lyonscf	Well, it's a map of maps
10:10	fliebel	Hm, what's that function called that is like map for nested sequences?
10:10	lyonscf	so I want to iterate over each element and take a couple of vals out of it and put it into a new list of maps
10:10	fliebel	lyonscf: A map is just like a seq of key-value paris when traversing.
10:10	edw	(map identity (sequence {:a 1 :b 2 :c 3}))
10:11	edw	fliebel: zip?
10:14	Raynes	fliebel: clojure.walk/postwalk?
10:14	lyonscf	edw: could you perhaps break that down for me.
10:15	tonyl	&(map identity {:a 1 :b 2 :c 3})
10:15	tonyl	,(map identity {:a 1 :b 2 :c 3})
10:16	clojurebot	([:a 1] [:b 2] [:c 3])
10:16	tonyl	$google sexpbot
10:16	fliebel	Raynes: Probably, but I thought it was in core.
10:16	Raynes	tonyl: sexpbot is down for a little bug fixing.
10:16	tonyl	Raynes: :( ok
10:22	Raynes	tonyl: I try to do this sort of thing late at night when everyone is asleep, but I actually slept through the night last night.
10:23	tonyl	no worries, I take my sleeping seriously as of lately
10:26	jcromartie	how do I create a Java vVector from a Clojure vector?
10:26	jcromartie	Vector
10:27	chouser	you're sure you need to?
10:27	jcromartie	I'm creating a JTree
10:27	jcromartie	and I figure the simplest route is the constructor that takes a vector of nodes
10:27	jcromartie	before I go making a proxy
10:28	chouser	Clojure vectors are java.util.RandomAccess, java.util.Collection...
10:29	chouser	but if you need to, ## (doto (java.util.Vector.) (.addAll [1 2 3 4]))
10:29	sexpbot	⟹ #<Vector [1, 2, 3, 4]>
10:30	jcromartie	hm
10:30	jcromartie	looks like to-array will work, there's an array constructor
10:47	edw	When I `lein repl' I get "Warning: problem requiring hooks: java.lang.IllegalAccessError: extract-javac-tasks is not public (javac.clj:1)". On Ubuntu 10.04 w/ Sun's JDK. Any ideas?
11:34	Bahman	Hi all!
11:35	tonyl	hello Bahman
11:37	Bahman	Hi tonyl!
11:43	Raynes	&(+ 1 (- 2 (* 3 (/ 4.0 10))))
11:43	sexpbot	⟹ 1.7999999999999998
11:43	Raynes	Yay!
11:43	fliebel	Raynes: What was that about?
11:43	tonyl	sexpbot is up
11:43	fliebel	Yay indeed!
11:44	garytr25	(+ 1 2 3)
11:44	clojurebot	suffusion of yellow
11:44	garytr25	&(+ 1 2 3)
11:44	sexpbot	⟹ 6
11:44	garytr25	nice!
11:45	edw	What's that first character sexpbot emits? A right-pointing arrow? A double-lined right-pointing arrow?
11:46	garytr25	yea
11:46	garytr25	(fn [] (+ 2 3 4))
11:46	garytr25	&(fn [] (+ 2 3 4))
11:46	sexpbot	⟹ #<sandbox6366$eval8383$fn__8384 sandbox6366$eval8383$fn__8384@8c0d5d>
11:47	garytr25	&((fn [] (+ 2 3 4)))
11:47	sexpbot	⟹ 9
11:47	garytr25	neato
11:47	garytr25	&(def x 5)
11:47	sexpbot	java.lang.SecurityException: You tripped the alarm! def is bad!
11:47	garytr25	haha ok
11:49	lucian	try let :)
11:52	garytr25	&(let [x 5] ((fn [y] (+ y 1)) x))
11:52	sexpbot	⟹ 6
11:53	fliebel	Can anyone tell me how I can make a protocol extend a final java class? Or anything else for that matter. stuartsierra said it to be possible, but I can't find anything about "protocol inheritance"
11:53	fliebel	http://groups.google.com/group/clojure/browse_thread/thread/0241042e15696cc9/256f6d4f55dd41a0#256f6d4f55dd41a0
11:57	kotarak	fliebel: (extend-type YouFinalClass YourProtocol (funA ...) (funB...))
11:58	kotarak	fliebel: there is no "protocol inheritance" but you can mix in functionality with mapos
11:58	kotarak	-o
11:58	tonyl	this might help http://clojure.org/Protocols
11:59	fliebel	kotarak: But it think extend makes my final class support my protocol, while I need my protocol to be based on the final class.
11:59	kotarak	fliebel: exactly. You can't extend final class with more functionality. Or any non-final class for that matter...
12:00	kotarak	fliebel: you have to patch your clojure version and make Atom non-final. Just as Alyssa suggested.
12:01	fliebel	kotarak: Then I don't get the point of Stuarts's response. What does he want me to do?
12:01	kotarak	fliebel: he wants you to write a protocol. Extend it to atoms and your stuff. Then it can serve as a common API.
12:02	fliebel	I'm not looking to make atoms.fly, if that is what I can do with extend. I need to implement the Atom "interface" rather.
12:03	tonyl	you need a type for implementation
12:03	tonyl	declare a type with the base protocol being the Atom interface and extend the methods
12:03	kotarak	fliebel: something like this: (defprotocol PAtom (swap! ...) (reset! ...)) and then do (ns your.namespace (:refer-clojure :exclude (swap! reset!)) (:use name.space.containing.protocol))
12:03	hiredman	I think that is a bad idea, better make new similar reference types
12:05	fliebel	Alright, so I can replace or supplement Atom, but not implement it.
12:06	kotarak	fliebel: you can do (extend-type clojure.lang.Atom PAtom (swap! [this f & args] (apply clojure.core/swap! this f args)) (reset! [this v] (clojure.core/reset! this v)))
12:07	kotarak	fliebel: then also atoms support your API
12:10	fliebel	huh… so I can 'replace' the methods of Atom to do what I want? That feels so much like monkeypatching…
12:11	fogus`	fliebel: In what way? Atom is not changed.
12:11	chouser	no, you'd just be using your own functions instead
12:12	fliebel	chouser: So I'm like shadowing Atom?
12:13	chouser	fliebel: kotarak is showing you how to explicitly manipulate your namespace so that the names 'swap!' and 'reset!' refer to your own protocol functions instead of the clojure.core/functions
12:14	chouser	completely different functions in different namespaces
12:14	chouser	not quite shadowing because you have to explicitly exclude clojure.core's functions from being put in your namespace.
12:14	fliebel	chouser: Yea, that sounds better. Just make my own multimethod swap! that does either core swap or custom swap, depending on type.
12:15	chouser	right, that's what he was showing you, only with a protocol instead of multimethod
12:15	fliebel	oh, right :) hm, I'll reread
12:45	garytr25	&(let [[x y] '(5 6)] ((fn [z a] (+ z a 1)) x y))
12:45	sexpbot	⟹ 12
12:48	amalloy	garytr25: ##((fn [[z a]] (+ z a 1)) '(5 6))) works too if you're just exploring destructuring
12:48	sexpbot	⟹ 12
12:49	garytr25	nice
12:57	amalloy	and also, '(5 6) is somewhat un-idiomatic; i'd usually use [5 6]. but (let [[x y] [5 6]]) kinda looks less magical, so if you want to be awed go with the quote :)
13:24	garytr25	programs work best when they look the most magical
13:24	Licenser	now I've a hard decision: I have a idea for a program (web apploication) and am not sure if I should try to write it in erlang or clojure
13:26	amalloy	Licenser: it seems like, by asking this question in #clojure, you've predetermined what answer you'd like to get
13:26	Licenser	amalloy: yes that is why I am tricky and also asked in #erlang :P
13:27	Licenser	now I can paralellize my decision making process
13:27	Licenser	and since both erlang and clojure are good for paralell stuff I think it fits
13:27	amalloy	Licenser: see what #fortran thinks
13:27	garytr25	clojure doesn't do message passing stuff like erlang
13:28	Licenser	amalloy: good idea
13:28	garytr25	you might have to do more work to scale it up?
13:29	Licenser	garytr25: yes that is a + for erlang
13:30	raek	garytr25: don't forget to take a look at the goodies in java.util.concurrent
13:30	raek	ehr, Licenser: I mean
13:30	raek	garytr25: sorry
13:31	Licenser	raek: nods I know that clojure does very well with concurrency
13:31	Licenser	my problem is I want to learn more aout both languages but am not sure which to choose here
13:32	raek	I'm preparing a mini-talk for the local clojure meeting about that stuff
13:32	Licenser	raek: web dev or concurrency?
13:33	raek	just want to make sure that people do not ignore the java stuff that clojure treats as "fully working, no extra wrappers required"
13:33	raek	Licenser: concurrency. but my last one was about web dev
13:34	Licenser	raek: happen to have slides to look at? :P
13:34	Licenser	hmm I could make a compromise and use both
13:35	Licenser	making it even more complicated
13:35	raek	very very mini... so no slides
13:36	raek	https://github.com/raek/lcug-guestbook
13:37	Licenser	kk
13:37	Licenser	was just curiose
13:37	Licenser	I get to cry since I can't use lein on my work PC fracking proxy's!
13:41	Licenser	okay the guys in #fortran were the most convincing - time to learn fortran
13:48	garytr25	i've heard you can write fortran in any language
13:52	bartj	I have a 10GB json file...any tips on how to go about reading it lazily?
13:53	fliebel	bartj: Write a json zipper? Hmm… Or strip the root element and read the sub elements.
13:53	hiredman	a single json object?
13:54	hiredman	you can't read a single json object lazily
13:54	chouser	really?
13:54	hiredman	[ … 10 gigs … ]
13:55	hiredman	the object goes from [ to ]
13:55	hiredman	thats readinga clojure form lazily
13:55	Licenser	you could query the contens laziely
13:55	chouser	yeah, but that could be represented as a lazy seq
13:55	fliebel	hiredman: Make it a zipper, and you can only read [ and then go depth first and such...
13:55	hiredman	fliebel: but thats not structured data
13:56	cemerick	json array elements could be read lazily, but object (maps), not so much.
13:56	hiredman	making a zipper out of a sequence of characters makes very little sense
13:56	bartj	my first idea was to use (read-json...) but that returns a PersistentArrayMap which doesn't implement ISeq (I think)
13:56	cemerick	I guess you could do k/v pairs shrug
13:57	fliebel	cemerick: everytime do do z/down you only need to read up ot the next [ or { if I'm correct.
13:58	cemerick	fliebel: pairing zippers with IO seems like a disastrous idea…
13:58	cemerick	bartj: jackson lists "streaming" as a feature, you could give it a try: http://jackson.codehaus.org/
13:59	joly	zipper would be on the JSON parse tree, which reads more characters from IO as needed?
13:59	fliebel	cemerick: Why? Do zippers need to be side-effect free? What about the xml zipper?
13:59	cemerick	holy crud, a 418-class JSON parser :-O
14:00	bartj	cemerick, it didn't cleanly build on the first try...so kind of looking for alternatives
14:00	cemerick	bartj: it's widely-used -- isn't it in central or some other repo?
14:01	hiredman	jackson does smile too
14:01	cemerick	fliebel: c.c.zip-filter.xml, you mean? It operates over a fully-realized XML data structure.
14:01	hiredman	clj-json is built on jackson
14:07	bartj	thank you all for the flurry of enthusiastic replies
14:07	bartj	I think I am going to jackson a shot once again
14:07	bartj	*give
14:07	chouser	c.c.lazy-xml lazily parses xml. It can be done.
14:08	chouser	I can't think why it couldn't be done for JSON similarly
14:10	fliebel	chouser: I agree :)
14:11	chouser	if you wanted the json objects and arrays to be represented by vanilla collections, that would be a problem
14:12	chouser	but something that implements java.util.Map and something else that implements java.util.RandomAccess to represent objects and array respectively could certainly consume the input stream lazily
14:12	fliebel	chouser: So what do you propose?
14:12	fliebel	chouser: What about lazy seqs or zippers?
14:13	chouser	lazy-xml ignores the problem that you end up with the whole thing in memory if you read all the way to the end
14:13	chouser	if that's a problem you'd have to do something more clever there.
14:13	fliebel	chouser: Even if you doseq?
14:14	chouser	lazy-xml returns lazy externally immutable objects, like lazy-seq, that cache their values to allow random access
14:14	chouser	wrapping those in a zipper works just fine
14:15	chouser	and walking that zipper with zip-filter also works fine. :-)
14:15	fliebel	awesome
14:16	chouser	but I have no recommendation for JSON, just suggesting it should be possible
14:19	fliebel	I remember someone mentioning a 2-way parser language, with something called lenses, anyone knows?
14:20	fliebel	ah http://www.seas.upenn.edu/~harmony/
14:23	fliebel	Before you can say 'supercalifragilisticexpialidocious' and after I finish a dozen other projects, I'll come up with an awesome lazy bidirectional Clojure parser framework.
14:26	cemerick	my point before re: zippers and IO was that, esp. in a situation where you've got a large data source involved, you will inadvertently allocate and retain indeterminately.
14:27	cemerick	i.e. z/left may cause you to hoover up a gig of data, and worse, not release your prior loc's contents
14:29	fliebel	cemerick: I'm not sure I get your point.
14:30	amalloy	fliebel: if you use a zipper to wrap some laziness around your IO, you'll have a hard time understanding/predicting what zipper operations will cause IO
14:30	fliebel	True, they might return instantly, or take a long time.
14:31	amalloy	fliebel: more importantly, zippers are complicated and i wouldn't be sure how much data they kept in memory
14:32	fliebel	But any lazy implementation of JSON is unpredictible in the amount of IO that is involved per item.
14:33	cemerick	fliebel: The point is that you don't have a choice as to what is retained by a zipper.
14:33	cemerick	If you're really working with large datasets, that's a problem.
14:34	fliebel	right...
14:35	cemerick	I'm not saying that zippers over e.g. lazy-xml don't work, but I'd be nervous about using them in cases where the laziness is there for a "good" reason.
14:36	fliebel	So what you're saying is that it's fine for doing lazy stuff, but not fro being lazy for the sake of not having 10gb of ram :)
14:37	amalloy	fliebel: have you considered tracking down the sadist who wrote a 10GB json file?
14:39	cemerick	amalloy: these things happen…
14:39	brehaut	usually from big slow moving corporations who arent tech companies
14:44	cemerick	I'm not sure being a "tech company" helps any if you've got to move NN gigs of data from here to there.
14:45	brehaut	cemerick: sure. but non-tech companies can turn NN megs of data into NN gigs of data
14:45	cemerick	ah; yeah, that can happen :-)
14:45	brehaut	through liberal application of new buzzwords they dont understand :)
14:46	brehaut	i learnt a lot about python's itertools and lazy evaluation working with that
14:58	rata_	hi all
14:58	rata_	has anybody used counted-sorted-sets to store maps?
14:58	rata_	chouser: do you know of a good comparison fn for storing maps in counted-sorted-sets?
14:59	chouser	depends on how you want it sorted, I suppose
15:02	rata_	chouser: I don't really want it sorted... I'm just concerned with fast nth, disj and conj
15:03	rata_	(nth is for rand-nth)
15:03	chouser	oh. hm... so like hash, but guaranteed unique. bleh.
15:06	rata_	mmm... do you mean using hash like (compare (hash m1) (hash m2))?
15:12	rata_	chouser: ^
15:14	dnolen	hmm man I really want real TCO. There isn't a good guide on how to convert mutually recursive tail fn calls into a lazy sequence is there?
15:14	hiredman	dnolen: trampoline is kind of nice
15:14	chouser	rata_: right, but hash isn't guaranteed unique
15:15	cky	dnolen: I'd say you should use SRFI 41, but, that's for Scheme only. :-P
15:15	hiredman	I also would love some TCO
15:15	dnolen	hiredman: yeah but it's too slow.
15:15	hiredman	infact, just this morning I said "all these jsrs and no tco"
15:16	dnolen	hiredman: I've been hacking away at this miniKanren impl, and it's pretty sweet. But it's incorrect, it has stack overflow errors on certain orderings because the Scheme impl assumes TCO.
15:16	hiredman	:/
15:16	cky	hiredman: http://blogs.sun.com/jrose/entry/tail_calls_in_the_vm
15:16	hiredman	I know
15:17	cky	hiredman: (This is all in the future tense, as far as I know.)
15:17	hiredman	by "all these jsrs" I was refering to the ones listed for java 7 and 8
15:17	cky	hiredman: Heh.
15:19	dnolen	for example is this safe? https://gist.github.com/732343
15:19	dnolen	if so I think I can do what I want.
15:20	Chousuke	looks safe to me
15:20	dnolen	sweeeeeeeeeeeet
15:20	Chousuke	the functions always return before the recursion happens.
15:20	dnolen	god bless rhickey
15:29	chouser	does java have a foreach?
15:29	brehaut	chouser: something like it since 1.5 i think
15:30	cemerick	for (String s : someIterable<String>) { … }
15:30	chouser	cemerick: thank you!
15:34	cky	Java's for-each loops aren't as cool as for-each in real languages, though. For example, you can't iterate through multiple iterables simultaneously.
15:35	cky	(Which is something I often find a use case for, and for which I've ended up having to write manual loops instead).
16:11	jaley	hi everyone. can macros be overloaded on arity too?
16:12	dakrone	jaley: yep
16:13	jaley	dakrone: thought so... and is it a sensible way to support optional arguments?
16:14	dakrone	depends, you could use '& args' also
16:14	jaley	dakrone: yeah but it'll be nicer for the call if the optional arg goes in the middle... :/
16:15	cemerick	jaley: keyword args to the rescue?
16:15	dakrone	why? normally options args go at the end
16:15	dakrone	yea, or pass a map
16:15	jaley	dakrone, cemerick: i'm aiming for (with-response r body) and (with-response r validator-fn? body)
16:16	jaley	dakrone: at least i think it'd be nicer if the body part was always at the end, as it's potentially long?
16:16	tonyl	you can use arity with that
16:16	tonyl	2 args or 3 args
16:17	dakrone	for that, arity seems easiest
16:17	jaley	tonyl: right, that was my thinking, but for some reason by 2 arg version calling the 3 arg barfs with "wrong number of args (3) ...
16:17	tonyl	what is the implementation that you have?
16:18	amalloy	jaley: probably wrong syntax for arity overloading?
16:18	jaley	amalloy, tonyl: right i suspect so, but i wasn't sure if what i was doing was even the right approach so i wanted to check :-)
16:18	amalloy	(defmacro stuff ([a b] b) ([a b c] (+ c b)))
16:18	dakrone	jaley: (defmacro foo ([a] a) ([a b] [a b]))
16:19	amalloy	your error sounds like you did something more like (defmacro stuff [a b] b [a b c] (+ c b))
16:19	jaley	let me pastebin it, i'll be 1 minute...
16:21	jaley	broken: http://pastebin.ca/2013238
16:24	fliebel	How many lines of code do you usually (re)produce in one day? I find it much harder to estimate time than LoC for a task. I was wondering if LoC is something reasonably constant. Inspired by a quote that all coders average at around 10 lines of code per day, where good coders spend more time thinking and bad coders on trial and error.
16:24	amalloy	jaley: the 2-arg version needs a `
16:25	brehaut	fliebel: i dont think you can ever turn LoC into a meaningful metric
16:25	jaley	amalloy: d'oh! thank you!
16:26	zztr	fiebel: +1 what brehaut said
16:26	amalloy	brehaut: it is a meaningful metric for, eg, estimating how big a hard drive to put on your vc server...:)
16:26	brehaut	amalloy: hah
16:27	tonyl	is there a way to know if a form is a macro?
16:27	amalloy	&(meta #'or)
16:27	sexpbot	⟹ {:macro true, :ns #<Namespace clojure.core>, :name or, :file "clojure/core.clj", :line 705, :arglists ([] [x] [x & next]), :added "1.0", :doc "Evaluates exprs one at a time, from left to right. If a form\n returns a logical true value, or returns that value and does... http://gist.github.com/732440
16:27	Raynes	&(meta for)
16:27	sexpbot	java.lang.Exception: Can't take value of a macro: #'clojure.core/for
16:27	Raynes	&(meta #'for)
16:27	sexpbot	⟹ {:macro true, :ns #<Namespace clojure.core>, :name for, :file "clojure/core.clj", :line 3582, :arglists ([seq-exprs body-expr]), :added "1.0", :doc "List comprehension. Takes a vector of one or more\n binding-form/collection-expr pairs, each followed by zero or mor... http://gist.github.com/732442
16:27	amalloy	Raynes: too slow
16:27	Raynes	amalloy: Damn. I was too slow.
16:28	Raynes	And again.
16:28	Raynes	tonyl: ##(:macro (meta #'for))
16:28	sexpbot	⟹ true
16:28	amalloy	&(-> for var meta :macro)
16:28	sexpbot	⟹ true
16:28	Raynes	Mine is shorter.
16:29	Raynes	Arguable more readable. Wanna fight about it?
16:29	tonyl	thanks, I didn't know there was metadata for that
16:29	Raynes	tonyl: A lot of core stuff even has line numbers in metadata.
16:29	Raynes	That's how the $source command works.
16:30	tonyl	wow nice to know
16:30	amalloy	Raynes: defn/defmacro include line numbers in the meta automatically
16:31	Raynes	amalloy: I assumed. Too bad def doesn't.
16:31	fliebel	So source just fetches those lines? I thought it'd be something with getting the actual datastructure that was used to produce it.
16:32	Raynes	fliebel: Naw, source just looks at the metadata and links to the line on Github.
16:32	amalloy	$source source
16:32	sexpbot	Source not found.
16:32	fliebel	Raynes: Oh, I was thinking about ##(source source)
16:32	sexpbot	java.lang.Exception: Unable to resolve symbol: source in this context
16:32	Raynes	fliebel: Oh, right.
16:33	amalloy	&(use '[clojure.repl :only [source]])
16:33	sexpbot	⟹ nil
16:33	amalloy	$source source
16:33	sexpbot	Source not found.
16:33	amalloy	&(source source)
16:33	sexpbot	⟹ Source not found nil
16:33	amalloy	bah
16:33	fliebel	source uses source-fn, which in turn does not have a source
16:35	fliebel	https://github.com/richhickey/clojure/blob/master/src/clj/clojure/repl.clj#L21
16:37	amalloy	&(-> clojure.repl/source-fn var meta ((juxt :file :line :source))
16:37	sexpbot	java.lang.Exception: EOF while reading
16:37	amalloy	&(-> clojure.repl/source-fn var meta ((juxt :file :line :source)))
16:37	sexpbot	⟹ ["clojure/repl.clj" 21 nil]
16:37	amalloy	&(-> clojure.repl/source var meta ((juxt :file :line :source)))
16:37	sexpbot	⟹ ["clojure/repl.clj" 43 nil]
16:38	amalloy	well, i guess it makes sense that the source isn't directly in the meta. i just don't understand why (source) can find source but not source-fn, when they both have line numbers
16:43	fliebel	I don't think I understand source-fn. How does it figure out how many lines to read? It seems to read up to :line, but then I get lost in Java pushback readers and stuff.
16:46	amalloy	fliebel: it uses the built-in (read) function to read a single sexp, and as a side effect writes each character it reads to the stringbuilder. then it throws away the sexp it read and returns the string
16:47	fliebel	amalloy: Ah, the ambiguity! I'm not sure I have found the Clojure read amongst the java.io read methods.
16:48	fliebel	Ah there it is...
16:48	amalloy	https://github.com/richhickey/clojure/blob/master/src/clj/clojure/repl.clj#L40
16:49	hiredman	that is a clever idea, but the implementation isn't so solid
16:50	amalloy	hiredman: the implementation of source-fn? i agree on both counts
16:50	hiredman	proxy and pbr and then wrap it in another pbr?
16:50	hiredman	proxy a
16:51	fliebel	And a lot of mutable Java stuff. Not sure it hurts that much in this case though.
16:52	amalloy	fliebel: bet you $N (for some small N) that it leads to the output of (source) having trailing spaces on occasion
16:53	fliebel	amalloy: Why would that happen?
16:53	fliebel	Would be fun to try… map over ns-publics, bind out to a string writer, call source-fn and see if it ends with a space.
16:53	amalloy	the pbr that appends to the stringbuilder can't know if the input stream gets pushed back. it's already appended to the string
16:54	amalloy	on thinking about it it probably is fine because (read) will never actually have to push back in order to read, but maybe there's some weird structure of source lines that would cause it
17:00	bortreb	how do I efficiently subsample a vector?
17:01	amalloy	bortreb: not sure what you mean by subsample. are you looking for ##(subvec [1 2 3 4 5] 2 4)?
17:01	sexpbot	⟹ [3 4]
17:01	bortreb	like, if I have a 25,000 vector and I take every 10th one to get a 2,500 vector
17:02	fliebel	amalloy: ##(not-every? identity (map #(.endsWith (or (source-fn (key %)) "") " ") (ns-publics 'clojure.core)))
17:02	sexpbot	java.lang.SecurityException: You tripped the alarm! ns-publics is bad!
17:02	amalloy	bortreb: take-nth probably isn't efficient since it falls back on treating the vec as a seq
17:04	jdrannbauer	,(hash-map :a :b :a :c)
17:04	clojurebot	java.lang.IllegalArgumentException: Duplicate key: :a
17:05	amalloy	&(vec (take-while identity (map [1 2 3 4 5 6 7 8 9] (take-nth 2 (range)))))
17:05	sexpbot	java.lang.IndexOutOfBoundsException
17:05	jdrannbauer	Hmmmmm... Anyone know why the docs suggest that I can supply duplicate keys to hash-map but it throws an exception if I do?
17:06	amalloy	&(doc hash-map)
17:06	sexpbot	⟹ "([] [& keyvals]); keyval => key val Returns a new hash map with supplied mappings."
17:06	amalloy	jdrannbauer: where are the docs that make you think you can do this?
17:07	jdrannbauer	Good question. Saw it at this url: http://clojuredocs.org/clojure_core/clojure.core/hash-map. usually a good reference.
17:07	amalloy	bortreb: anyway i think the answer will be vaguely like what i did above. use the vector as a function, and call it with the indexes you want
17:07	bortreb	ah
17:07	amalloy	just make sure you don't call it with bad indexes
17:08	bortreb	it's just (vec (map v (range 0 (count v) n))) to so subsampling because count is fast
17:09	amalloy	jdrannbauer: whoa that must be old
17:09	amalloy	bortreb: oh, sure
17:09	jdrannbauer	Ah! Cool. Too new to clojure to have noticed. Thanks for the heads up!
17:11	jdrannbauer	amalloy: Is there a sugary way to do what I am looking for? I want to convert [:a "b" :a "c"] to {:a "c"}
17:11	amalloy	jdrannbauer: ##(into {} [:a "b" :a "c"])
17:11	sexpbot	java.lang.IllegalArgumentException: Don't know how to create ISeq from: clojure.lang.Keyword
17:11	amalloy	jdrannbauer: ##(into {} (partition 2 [:a "b" :a "c"]))
17:12	sexpbot	java.lang.ClassCastException: clojure.lang.Keyword cannot be cast to java.util.Map$Entry
17:12	amalloy	bahhhhh
17:12	hiredman	,(apply hash-map [:a "b" :a "c"])
17:12	clojurebot	java.lang.IllegalArgumentException: Duplicate key: :a
17:12	hiredman	no kidding
17:12	chouser	,(into {} (map vec (partition 2 [:a "b" :a "c"])))
17:12	clojurebot	{:a "c"}
17:12	chouser	meh
17:12	amalloy	ah right, map vec. thanks chouser
17:12	fliebel	chouser: I'm to slow, was about to try that.
17:13	chouser	I wouldn't call it sugary
17:14	chouser	,(let [v [:a "b" :a "c"]] (zipmap (take-nth 2 v) (take-nth 2 (next v))))
17:14	clojurebot	{:a "c"}
17:14	jdrannbauer	Thanks everybody. Not as sugary as I was hoping but does exactly what I need.
17:15	fliebel	something like this.. but it doesnt work yet,,, maybe I'm stilll fast enough (reduce into {} (partition 2 [:a 1 :a 2]))
17:15	jdrannbauer	chouser: oooh, that's pretty cool.
17:16	jarpiain	bortreb: you could do something like this if you need the vector interface: https://gist.github.com/732529
17:23	jaley	can anyone explain the *-suffix naming convention?
17:24	cemerick	foo* often indicates a helper fn for a "public" foo fn or macro, or a function that is a variation of a primary foo implementation
17:25	jaley	cemerick: thanks!
17:31	hd	I fail to use "mvn clojure:swank" on windows vista, although I'm using the newest versions clojure-maven-plugin:1.3.8-SNAPSHOT and swank-clojure:1.3.0-SNAPSHOT
17:32	hd	The error is the same as here http://goo.gl/moVYc
17:33	hd	Exception in thread "main" clojure.lang.LispReader$ReaderException: java.lang.Exception: Invalid token: C:
17:34	hd	Can anybody help?
17:35	cemerick	hd: I'd post to that thread and ask Mark to clarify where you can find the proper fix (it doesn't look like he explicitly states where a staged release is).
17:36	hd	I downloaded it from github and installed it from source, but got the same error.
17:36	cemerick	an even better reason to post. Squeaky wheel, and all that. :-)
17:36	hd	[INFO] --- clojure-maven-plugin:1.3.8-SNAPSHOT:swank (default-cli) @ m2doc ---
17:36	hd	Exception in thread "main" clojure.lang.LispReader$ReaderException: java.lang.Exception: Invalid token: C:
17:36	hd	at clojure.lang.LispReader.read(LispReader.java:180)
17:36	hd
18:35	amalloy	chouser: ##(apply assoc {} [:a 1 :a 2])
18:35	sexpbot	⟹ {:a 2}
18:35	amalloy	looks like the sugar jdrannbauer was looking for before he left
18:48	jave	has anyone got a clojure 1.2.0 applet working, in openjdk?
18:59	pdk	how many folks use slime here
18:59	pdk	dumb q dealing with how to actually send it restarts when it gets an error
19:00	shachaf	pdk: You'll probably have much better success if you ask it than if you ask about asking it.
19:00	pdk	probably :p
19:01	pdk	say if i do M-x slime to start slime
19:01	pdk	then in inferior-lisp buffer i try putting in something that causes an error like (thisfunctiondoesn'texist)
19:02	bortreb	how can I make my objects defined with defrecord print in their own special way?
19:02	pdk	then i dunno how to actually input one of the restarts it lists through the buffer so i just sit there :p
19:02	pdk	clicking on a restart in the list it gives seems obvious but apparently not, etc
19:02	tonyl	b
19:03	pdk	!
19:03	tonyl	bortreb: implementing the Object.toString method, i think that is how it is
19:03	pdk	cool beans tonyl
19:03	pdk	so i can just hit the top row numbers to use the restart of that number too
19:03	tonyl	pressed enter too soon wih t
19:03	pdk	though how does it handle entering a restart by name
19:04	tonyl	i don't use slime, sorry i am not
19:04	tonyl	m
19:04	tonyl	u
19:04	pdk	b surprisingly enough did something though so it's unintentional help :p
19:04	tonyl	lol
19:06	bortreb	tonyl: thanks! I just forgot to recompile my namespace
19:08	bortreb	er, actually that doesn't work after all
19:10	bortreb	you apparently need to also define the print-method and print-dup multimethods for your defrecord type
19:10	bortreb	then it works fine
19:10	tonyl	uh interesting
20:35	islon	does anyone know hot to remove all nils from a seq?
20:35	islon	*know how to
20:35	brehaut	,(filter identity [1 2 nil nil 3 nil])
20:35	clojurebot	(1 2 3)
20:36	islon	thanks
20:36	brehaut	no worries
20:37	brehaut	oh
20:37	brehaut	that also filters out falses
20:37	brehaut	how about
20:37	brehaut	,(remove nil? [nil 1 2 3 nil 4])
20:37	clojurebot	(1 2 3 4)
20:37	brehaut	thats way smarter
20:38	islon	yes, my list can't contains falses anyway
20:39	jcromartie	anybody ever notice some weird buffering issues with lein repl?
20:39	jcromartie	like, with lots of output, sometimes it hangs and I have to type something in before I get the rest of it
20:39	technomancy	jcromartie: there were flushing bugs in 1.3; 1.4 is better
20:40	jcromartie	k
20:41	amalloy	&(keep identity [nil 1 false 2])
20:41	sexpbot	⟹ (1 false 2)
20:41	amalloy	brehaut, islon: ^^
20:41	brehaut	amalloy: nice
20:42	islon	good
20:42	amalloy	&(keep last [[1 2] [1 false] []])
20:42	sexpbot	⟹ (2 false)
20:42	amalloy	keep is a nice little combo of map/filter
20:50	islon	does anyone knows the function that return the intersection of two seqs?
20:55	jcromartie	islon: have you checked out clojure.set?
20:56	jcromartie	&(clojure.set/intersection #{1 2 3} #{2 3 4})
20:56	sexpbot	⟹ #{2 3}
20:56	islon	jcromartie: thanks, i used clojure.set/difference
21:01	aligole	hey guys
21:03	aligole	anybody here knows how I can overload/ override + to be able to add a number to a list of lists of numbers like (+ 3 ((1 2) (3 4))
21:04	jcromartie	why?
21:04	clojurebot	http://clojure.org/rationale
21:04	jcromartie	thanks, clizzin_
21:04	jcromartie	clojurebot:
21:04	clojurebot	#<ClassCastException java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to [Ljava.lang.String;>
21:04	jcromartie	durrrrrrrrrr
21:04	aligole	(+ 3 ((1 2) (3 4))
21:06	aligole	raek: do you have a minute?
21:08	aligole	jcromartie: you asked me? "why"
21:08	jcromartie	yeah
21:08	aduric	Hi, anyone have any experience with clj-plaza?
21:08	aligole	sorry
21:08	jcromartie	I'm not sure what you want to do
21:09	clizzin_	jcromartie: haha, i was wondering why someone said my name in here
21:09	jcromartie	heh
21:10	aligole	I'm trying to implement a Matlab like thing! and I need to have and add function for matrices
21:11	aligole	i can write function to do this but it would be more convenient if + could be used to add numbers to all the nubmbers in a list
21:12	aduric	Anyone know what the error: "[java.lang.IllegalArgumentException] No implementation of method" usually means?
21:12	islon	,(map + [1 2 3 4] [3 5 6 7])
21:12	clojurebot	(4 7 9 11)
21:12	aligole	,(map + [1] [3 5 6 7])
21:12	clojurebot	(4)
21:12	jcromartie	aligole: I think that part of the rationale of Clojure is to avoid monkey-patching built-in functions
21:12	aligole	not what I need
21:13	jcromartie	so overriding + is not a good idea
21:13	jcromartie	unless you wanted to make a special context for it
21:13	jcromartie	like a macro that replaces + with your own function
21:13	jcromartie	which is what people do to build sub-languages
21:14	aligole	that sounds about right, I may need to do that, so I need to define a macro with the same name "+"
21:15	aligole	cool, let me try it
21:15	amalloy	aligole: no, just a function named + will be sufficient
21:15	jcromartie	no
21:15	jcromartie	I mean sure
21:15	jcromartie	you can redefine + in a namespace
21:15	amalloy	jcromartie was, i think, suggesting you define a macro (replace-pluses)
21:16	jcromartie	I'm not really suggesting it...
21:16	aligole	:)
21:16	jcromartie	first I'd suggest using something other than +
21:16	jcromartie	because + means +
21:16	jcromartie	:)
21:16	amalloy	heh, yes
21:16	jcromartie	like vec+
21:16	jcromartie	that's clearer
21:16	jcromartie	I mean
21:16	jcromartie	matrix+
21:17	amalloy	jcromartie: i think he actually wants something like scalar+, for adding a scalar to a matrix, but that's his problem
21:17	jcromartie	yeah
21:17	jcromartie	yeah if you were going to define a matrix math library, you'd name them in that context
21:19	aligole	I like to use + for all adding purposes, I don't see why it is not a good idea. and yes I am making a limited matrix library
21:20	aligole	Clojure's promis is to let you modify the language to your needs, isn't it?
21:20	hiredman	aligole: nope
21:20	brehaut	aligole: thats a really imprecise statement in a lisp
21:21	aligole	hiredman: WHAT?! why not? isn't it a LISP? I've done this in arc before very easy it was!
21:21	hiredman	clojure.core/+ is for fast adding of numbers, if you want a generic addition operator, there is one in contrib
21:21	hiredman	right, and look where that got arc...
21:21	jcromartie	heh
21:22	aligole	oh, I didn't know, where in contrib?
21:22	jcromartie	aligole: by all means, define + in your matrix math lib
21:22	jcromartie	you can exclude + from the namespace
21:22	jcromartie	but I think you'll get tired of writing clojure.core/+
21:23	amalloy	&(require '[clojure.core :as [c]])
21:23	sexpbot	java.lang.ClassCastException: clojure.lang.PersistentVector cannot be cast to clojure.lang.Symbol
21:23	amalloy	&(require '[clojure.core :as c])
21:23	sexpbot	⟹ nil
21:23	amalloy	&(c/+ 1 2 3)
21:23	sexpbot	⟹ 6
21:23	amalloy	jcromartie, aligole: ^^
21:24	aligole	cool
21:24	jcromartie	wait... sexpbot maintains state for you?
21:24	jcromartie	&(def x 1)
21:24	sexpbot	java.lang.SecurityException: You tripped the alarm! def is bad!
21:24	jcromartie	oh
21:24	aligole	but still I am confused, why I can't have a generic +
21:25	aligole	hiredman: do you remember where in contrib is that generic +
21:29	amalloy	generic-math?
21:30	vIkSiT	hi all
21:30	aligole	there is a generic + in generic/arithmatic.clj as well
21:30	vIkSiT	When doing a lein compile, I find that it gets stuck at the "compiling namespace" step
21:30	vIkSiT	is there a way to see what might be going wrong?
21:30	vIkSiT	(some sort of a verbose mode, perhaps)?
21:31	danlarkin	vIkSiT: how long have you waited?
21:31	vIkSiT	quite some time (ran it for almost 20 minutes)
21:32	danlarkin	oh gosh, okay that's certainly long enough
21:32	vIkSiT	hehe yeah, i lein compiled and was doing something else
21:32	vIkSiT	lein compile works fine on another project
21:32	vIkSiT	top shows 2 java processes taking 5.3 and 5.2% mem respectively
21:34	vIkSiT	also the lib/ size is only 5M, whereas lein works fine for a project with 18M of libraries
21:34	aligole	hiredman, amalloy, jcromartie: http://clojure.org/multimethods
21:35	vIkSiT	danlarkin, ideas?
21:35	brehaut	aligole: multimethods are the exception, not the rule. (partly because dispatch is slower than static fns)
21:36	danlarkin	vIkSiT: nope :( could be a bug, I suggest reporting it
21:37	amalloy	aligole: https://github.com/clojure/clojure-contrib/blob/master/modules/generic/src/main/clojure/clojure/contrib/generic/arithmetic.clj
21:39	aligole	brehaut: I agree if performance is the first priority, but in my case it is not,
21:40	aligole	amalloy: thanks, just was reading that
21:40	brehaut	aligole: sure, then it'll work fine
21:41	vIkSiT	dakrone, aaah. quick question - how does one compile a (future) function in a file?
21:41	vIkSiT	I had a variable called (def f (future (myfn params)))
21:41	vIkSiT	er i meant danlarkin*
21:42	danlarkin	what do you mean how do you compile it
21:42	vIkSiT	danlarkin, in the sense - i've got the def within my file, and the function it wraps around basically tails a file (and waits on it).
21:43	vIkSiT	i'm guessing the compilation process initiated this
21:43	vIkSiT	my question is - how would i lein compile code which contains a (future) fn call like this?
21:44	danlarkin	are you sure you need to be compiling in the first place?
21:44	danlarkin	I know that's not your question, but I'm obligated to ask
21:44	vIkSiT	danlarkin, well, i need to create a JAR for my program so i can deploy it :)
21:45	vIkSiT	danlarkin, is there another way btw? (apart from starting a REPL, not sure thats advisable in production)
21:45	danlarkin	you don't need to complie clojure to deploy it in a jar
21:45	vIkSiT	hmm
21:46	vIkSiT	but lein jar had the same issue
21:46	vIkSiT	does lein jar evaluate the code, perhaps?
21:47	danlarkin	yeah your problem is the def
21:48	danlarkin	I assume
21:49	vIkSiT	I could ping technomancy and check as well..
21:52	amalloy	vIkSiT: (defs) are necessarily evaluated at compile time, otherwise (defn foo [] x), which expands to (def foo (fn [] x)), wouldn't do anything when you compile
21:52	vIkSiT	amalloy, indeed
21:53	amalloy	to prevent this from happening, you need (defn make-f [] (future (myfn params)))
21:53	amalloy	then when you want to do something with it, call (make-f) to get out a logger
21:55	amalloy	and make sure that make-f isn't called in the global scope. call it from (-main) or whatever
21:55	vIkSiT	amalloy, ah
21:55	vIkSiT	good idea - let me try that!
21:58	amalloy	vIkSiT: a pretty general strategy when you don't want something evaluated is to put it into a function :P
21:58	vIkSiT	amalloy, is -main the only function not eval'd?
21:58	amalloy	vIkSiT: they're all evaled
21:58	vIkSiT	amalloy, hehe
21:58	amalloy	but they're only called if you call them
21:58	vIkSiT	ah but a def when evald will have invoked the future fn..
21:58	vIkSiT	right
21:58	amalloy	no
21:59	amalloy	well yes, a def
21:59	amalloy	which is why, as i said, you can't make it a top-level thing. shove it inside a function
21:59	amalloy	&(future (println 1))
21:59	sexpbot	⟹ #<core$future_call$reify__5500@3c2bdf: nil>
21:59	amalloy	&(fn [] (future (println 1)))
21:59	sexpbot	⟹ #<sandbox6366$eval8635$fn__8636 sandbox6366$eval8635$fn__8636@b579ac>
22:00	amalloy	only one of those two things will have printed to the stdout on sexpbot's server
22:00	vIkSiT	right
22:00	vIkSiT	the first one
22:00	amalloy	right. same is true if you'd lein jar/compile'd it
22:00	vIkSiT	gotcha
22:01	vIkSiT	whew. it works :)
22:02	amalloy	hurrah. if it didn't, i'd have to re-evaluate my perspective on reality
22:02	vIkSiT	haha
22:04	vIkSiT	couple of questions about reading params from the CLI. right now, I've just defd two global vars (def a) and (def b), and then i read the values from the CLI and (def them from within the -main function
22:04	vIkSiT	is this general practice in terms of keeping global state?
22:04	vIkSiT	(for instance, if i want to read/write to a configuration file)
22:06	tomoj	would be nice to be able to switch between configuration profiles easily
22:07	tomoj	oh, just place a file and read it I guess
22:07	amalloy	vIkSiT: (def args (atom {:a 10, :b 20})) (defn -main [] (swap! args assoc :a (read) :b (read))) is the hacky approach i would use
22:07	amalloy	having just one var with all the args appeals to me
22:08	vIkSiT	ah
22:08	vIkSiT	makes sense
22:08	brehaut	vIkSiT: using a (couple of) vars are fine if you dont expect them to change
22:08	brehaut	vIkSiT: but if you can just pass the appropriate values through to the real program from -main that is nicer (IMO)
22:09	vIkSiT	agreed
22:09	tomoj	I think I'll just put some clojure forms in a file and read them
22:09	jcromartie	is there something weird about defmulti that the dispatch function isn't updated when reloading a namespace?
22:09	vIkSiT	but i'm trying to interop with an existing java program
22:11	amalloy	jcromartie: the old defmethods will stay attched to the original defmulti; to attach them to the new one you'll need to reload the defmethods too
22:11	amalloy	not sure if that's the problem you're having
22:11	jcromartie	the defmulti and defmethods are all in the same ns
22:12	amalloy	jcromartie: actually this sounds a lot like a problem i had, now that you mention it. i never figured it out; let me know if you do
22:36	scottj	Is there a fn for (concat (butlast coll) (f (last coll)))?
22:37	scottj	this is where a smalltalk method finder would come in useful.
22:44	amalloy	scottj: i don't think there is, and it would have to be pretty slow. maybe you can modify what you've done to get you to the state where you want this function?
22:58	pdk	little pop quiz
22:58	pdk	if i'm evaling stuff with slime and i write something that would lead to an infinite loop
22:59	pdk	what would you do to kick it in the pants and make it cancel that so you can eval other stuff and get printouts again
23:00	scottj	you can try C-c C-c ad infinitum but you'll probably have to kill java proc and restart it.
23:00	pdk	now i'd need to know how to hook emacs and slime to the new java proc i make without restarting those too :p
23:01	pdk	so i could keep working seamlessly like nothing happened after the inferior lisp is restarted
23:01	pdk	in the case of working on a file in slime mode at least
23:03	scottj	if you use lein swank you just have to M-x slime-connect
23:04	scottj	alias les='lein swank & sleep 5; emacs-client -e "(slime-connect 4005)"'