#clojure – 2011-04-30

2011-04-30

01:36	semperos	chrissbx: thanks for pointing out that repo
01:36	semperos	I piggy-backed on Seth Schroeder's seplunk-clj-irc lib, since he already took care of scraping the HTML for the info
01:37	semperos	spelunk-clj-irc, rather
02:19	bartj	can I use leningen to create a jar for a Java application ?
02:19	kencausey	lein help
02:19	kencausey	uberjar might be what you are looking for but read the details
02:21	bartj	kencausey, I fail to understand the diff b/w jar and uberjar
02:24	kencausey	via google: http://zef.me/2470/building-clojure-projects-with-leiningen
02:26	kencausey	It appears to be determined by how you expect to deliver dependencies, jar assumes you will provide the dependencies seperately, uberjar packages all into one. That's my understanding anyway.
02:32	amalloy	yes. uberjar creates your jar, and then stuffs all your dependencies into it as well, so that the end user doesn't need dependency-resolution tools
02:32	amalloy	it should really only be used for deploying end users
03:09	bartj	amalloy_, kencausey thank you! I am getting started using lein.
03:47	bartj	is it incorrect to use: clojure 1.1.0-master-SNAPSHOT ?
03:47	bartj	and clojure-contrib 1.0-SNAPSHOT ?
03:48	bartj	in the lein build file
03:48	hiredman	that is very old
03:49	bartj	and isn't even present in the clojars too, I believe
04:06	bartj	instead of .clj file, I have a Blah.java file
04:06	bartj	and my project.clj file has a ":java-source-path true"
04:07	bartj	yet, the class file for the Blah.java doesn't seem to get generated
04:26	bartj	is it not possible to use a Java class with a main method as the "starting" class ?
04:26	bartj	when using leiningen?
05:14	fliebel	bartj: I assume there is a reason some people use Maven, but I don't know if lein can do it.
05:17	fliebel	How would you guys like you maps matched? Exact keys or at least the specified keys?
05:17	fliebel	( http://pepijndevos.nl/clojure-micro-pattern-matcher )
05:42	thorwil	fliebel: both/either?
05:47	raek	bartj: you can compile java source files with lein nowadays, however :java-source-path should be set to a path, not true
06:03	raek	bartj: https://gist.github.com/949577
06:03	raek	it is indeed possible :)
06:04	raek	just run "lein uberjar", and then you can run it with "java -jar foo-1.0.0-SNAPSHOT-standalone.jar"
07:01	kzar	Does anyone know what's wrong with this Enlive selector? (It broke when I tried to add in the rel=stylesheet part, otherwise it works.) [[:head] [:link (html/attr= :rel "stylesheet") (html/nth-of-type 1)]]
07:18	bartj	raek, thanks, I'll try that out!
07:34	fliebel	MayDaniel: I noticed you forked my gist. Just saying I've added a lot of stuff since then. :)
08:08	fliebel	I'm using sleep and notify inside a locking macro, but it still claims to give an java.lang.IllegalMonitorStateException. Does using recur or calling other functions affect the locking?
08:12	fliebel	Apparently… Why does recur do that?
08:25	fliebel	Can I check what holds the monitor to an object?
10:23	fliebel	(assert (not (possible? seque)))
10:25	fliebel	I'd bake an apple pie for the one to prove me wrong :)
13:07	mec	,(clojure.lang.RT/nextID)
13:07	clojurebot	1331
13:07	mec	,(clojure.lang.RT/nextID)
13:07	clojurebot	1334
13:07	fliebel	Is that what gensym uses?
13:08	mec	why does that update different amounts? On mine its by 5, but in the source it should be just by 1
13:08	mec	fliebel: ya
13:08	fliebel	mec: I assume that's because of aother parts of Clojure consuming them as well?
13:10	mec	nextID is direct and the only thing that uses it otherwise is gensym, i cant make heads or tails of it
13:13	mec	oh maybe the reader uses them
13:13	mec	or printer
13:14	mec	,[(clojure.lang.RT/nextID) (clojure.lang.RT/nextID)]
13:14	clojurebot	[1337 1338]
13:14	mec	looks that way
13:14	mec	,clojure-version
13:14	clojurebot	{:major 1, :minor 2, :incremental 0, :qualifier ""}
13:15	fliebel	hm, I also have not figured out yet in which cases a transient mutates or copies.
13:16	mec	when the underlying data structure changes for efficiency
13:16	fliebel	mec: Sure, but when and where does that happen?
13:21	mec	{} are arraymaps that change to hashmaps with more than 8 keys, i think thats about it
13:49	fliebel	How cool is that, using a queue to manage a queue.
13:52	fliebel	Anyway, it works perfectly and takes everything you trow at it.
13:54	fliebel	… except for the moronic test :)
14:27	zrilak	Hi folks, noobish question ahead.
14:28	fliebel	zrilak: bring it on! I love questions :)
14:30	arohner	clojurebot: questions
14:30	clojurebot	Titim gan éirí ort.
14:30	arohner	I guess it forgot that one
14:30	fliebel	arohner: What one?
14:30	fliebel	~ask
14:30	clojurebot	Excuse me?
14:30	arohner	something about don't ask if you can ask a question. just ask the question
14:30	zrilak	argh, this is so complex, I need to find a good way to write it down :)
14:31	zrilak	I'm trying to define something like this:
14:31	fliebel	Well, he did not ask anything really, he just said hi :)
14:31	zrilak	I have a state of a game, over which I'll be performing a number of effects during the course of the program.
14:31	fliebel	I like this one better; xy?
14:32	zrilak	Ergo:
14:32	zrilak	(defprotocol Effect
14:32	zrilak	"An in-game effect."
14:32	zrilak	(act [_ state] "Make the effect act on the game state."))
14:33	zrilak	Effects are logically grouped into 30 or so classes of effects, which differ by their behavior and parameters. I call those classes "Powers".
14:33	zrilak	Good so far? :)
14:33	fliebel	zrilak: I'm doing something with games currently: https://github.com/pepijndevos/Begame/blob/master/src/examples/pong.clj#L12 Not 3D though.
14:33	arohner	zrilak: yeah
14:34	zrilak	fliebel: cool, I'll take a look; I'm not going into 3D yet, just interested in designing a semi-universal engine.
14:34	fliebel	zrilak: Well, you're looking at one there, hopefully :P
14:34	zrilak	Anyways, to help build different Effects, I have this:
14:34	zrilak	(defprotocol Power
14:34	zrilak	"Takes a parameter map and yields an effect."
14:34	zrilak	(actualize [_ ctor-map] "Build an effect."))
14:35	fliebel	The act method takes a world and the current object and returns the new object, in my case.
14:35	arohner	zrilak: btw, if you're pasting multi-line code, it's better to use gist or pastie or something
14:35	zrilak	ah, good point
14:35	zrilak	why should I be inlining everything here
14:38	zrilak	ah, actually, pizza is here; I'll be back later -- thanks for your patience so far!
14:56	fliebel	How can I use a gist in a project? Gists have git access, and I heard lein and cake support some form of checkouts. Will that work?
15:05	fliebel	There, project-in-a-gist: https://gist.github.com/946857
15:30	fliebel	Do we have a canonical answer to this? https://twitter.com/#!/bramduvigneau/status/64408805215191040
15:31	fliebel	Mayabe clojurebot knows… clojurebot, Clojure is a nice language, do you know why?
15:31	fliebel	why?
15:31	clojurebot	http://clojure.org/rationale
16:01	fliebel	When I run lein jar, it prints Copying 1 file to <lib path> and then… nothing.
16:04	fliebel	I don't think lein likes me making a jar with :source-path ""
16:10	amalloy	anyone?
16:10	clojurebot	Please do not ask if anyone uses, knows, is good with, can help you with <some program or library>. Instead, ask your real question and someone will answer if they can help.
16:10	amalloy	fliebel: ^
16:10	miwillhite	I'm brand new to clojure and am having issues importing duck-streams from clojure-contrib
16:11	miwillhite	Please take a look at the following code and error…
16:11	miwillhite	http://pastebin.com/r4cynuza
16:11	miwillhite	I set up my project with leiningen
16:12	mefesto	miwillhite: can you use clojure-contrib v1.2.0 instead?
16:12	fliebel	amalloy: Is that to me, or just to show the right command? ;)
16:12	raek	miwillhite: use clojure-contrib 1.2.0 instead
16:12	amalloy	fliebel: well, you didn't ask "can anyone help me with clojurebot?" so i'll give you the benefit of the doubt
16:13	raek	you usually get this wierd "RestFN" error when you mix incompatible ahead of time compiled versions of libraries
16:13	amalloy	miwillhite: duck-streams are also pretty old, i think
16:13	miwillhite	whats the best way to read the contents of a file?
16:13	raek	,(doc slurp)
16:13	clojurebot	"([f & opts]); Reads the file named by f using the encoding enc into a string and returns it."
16:14	raek	miwillhite: that, and maybe functions from clojure.java.io (which superscedes duck-streams)
16:14	raek	(slurp is included in clojure.core nowadays)
16:15	fliebel	amalloy: Okay. I admit I did not add much detail or an explicit question. The question would be: How can I make a jar with leiningen when using a custom source path?
16:15	miwillhite	ah yeah okay
16:15	miwillhite	thanks
16:15	amalloy	fliebel: man, i was just showing you how to use the command
16:15	amalloy	$google lein project.clj sample
16:15	sexpbot	First out of 1810 results is: technomancy/leiningen - GitHub
16:15	sexpbot	https://github.com/technomancy/leiningen
16:16	amalloy	that said, i think the sample project.clj has that
16:16	raek	miwillhite: well, slurp returns the file as one big string. you could also check out line-seq (just give it what clojure.java.io/reader returns)
16:16	amalloy	fliebel: https://github.com/technomancy/leiningen/blob/master/sample.project.clj#L129
16:16	fliebel	amalloy: yeayea, I know, it goes :source-path "", but then lein does not want to make a jar anymore, onless I specify that I want to aot and exclude source files.
16:17	amalloy	fliebel: you said "custom source path"; you want your source path to be the project root?
16:17	fliebel	amalloy: yes. gists don't have a directory structure ;)
16:17	amalloy	if so i'd try "/" and "."; i don't expect "" to work
16:18	fliebel	okay, I'll try. Just using it from the repl works fine though.
16:18	miwillhite	okay one more question…what is the best practice for file paths? say I want to read a file at the root of my application…
16:19	mefesto	miwillhite: if the file is bundled in your jar as a resource then you can use clojure.java.io/resource for that
16:20	fliebel	amalloy: Exception in thread "main" java.util.zip.ZipException: duplicate entry: project.clj
16:20	amalloy	fliebel: makes sense. i suppose
16:20	fliebel	amalloy: Yea, there was some exlude command...
16:20	raek	miwillhite: to do what mefesto said, just make a resources/ directory in your project, and leiningen will include it in the classpath and generated jars
16:21	fliebel	https://github.com/technomancy/leiningen/blob/master/sample.project.clj#L146
16:22	raek	miwillhite: but for arbitrary paths in the file system, you can join the segments in a platform independent way with clojure.java.io/file (in java-land, a 'file' is a file path...)
16:22	raek	a File object can then be passed to reader, etc
16:23	miwillhite	okay thanks guys, I'll take a look into that stuff
16:23	fliebel	amalloy: And then I'm back where I started, and where lein hangs after saying "Copying 1 file to /Users/pepijndevos/git/seqex/lib"
16:25	fliebel	So, either I need to debug lein somehow, or just live with aot'd files.
16:34	Somelauw	(Integer/parseInt (read-line)) to read nums
16:44	currentB	is there a way to use partial to create a function by only giving it it's named arguments, which come after its regular args?
16:45	fliebel	currentB: No, but you can use an anonymous function.
16:45	currentB	for example (defn func [x y & {:keys [named-args]}] name-args) then call (partial func :named-args "test")
16:46	amalloy	currentB: you could also use my argument-reordering HOF. something like (partial (reorder f) :name x :size 10)
16:46	fliebel	#(function %1 %2 :arg 2 :argb 3)
16:46	amalloy	though i suspect that's too much trouble in practice and fliebel's answer is better
16:46	Somelauw	(map #(read-string (read-line)) (range numPoly)))]
16:46	currentB	cool thanks guys
16:47	amalloy	Somelauw: no good
16:47	Somelauw	(map #(read-string (read-line)) (range numPoly)))
16:47	amalloy	the function you pass to map needs to accept an argument
16:47	fliebel	Somelauw: You could use repeatedly
16:47	amalloy	you want (repeatedly num-poly (comp read-string read-line))
16:47	Somelauw	hmm, so should I use for here?
16:48	Somelauw	,(repeatedly 5 3)
16:48	clojurebot	java.lang.RuntimeException: java.lang.ClassCastException: java.lang.Integer cannot be cast to clojure.lang.IFn
16:48	Somelauw	,(repeatedly 5 #3)
16:48	clojurebot	No dispatch macro for: 3
16:49	Somelauw	ok
16:50	Somelauw	,(#(3))
16:50	clojurebot	java.lang.ClassCastException: java.lang.Integer cannot be cast to clojure.lang.IFn
16:51	fliebel	,(#(do 3))
16:51	clojurebot	3
16:51	amalloy	Somelauw: you could keep writing nonsense and hoping for the best, or tell someone what your goal is
16:53	amalloy	fliebel: you're encouraging evil. (constantly 3)
16:55	fliebel	amalloy: Mhpf, maybe. Idk, I'm just going to bed. Good luck, and good night :) Maybe tomorrow will hold less evil.
16:56	amalloy	hah
16:56	Somelauw	thanks for the evilness
16:57	fliebel	amalloy: I hope you did not mean I am encouraging evil constantly? ;) But, Somelauw, amalloy has some point, it is more important to figure out what you want to do than how you are trying to do it.
16:58	fliebel	~xy
16:58	clojurebot	xy is http://mywiki.wooledge.org/XyProblem
16:58	amalloy	fliebel: i will put up with evil from someone trying to deliver a coherent queue
16:59	fliebel	amalloy: haha, I have something that works, but I don;t like the idea of using several queue to coordinate one.
16:59	Somelauw	Well, I want to read numPoly numbers from the commandline.
17:00	fliebel	amalloy: https://gist.github.com/934781
17:00	Somelauw	And I was testing the repeatedly function.
17:18	Somelauw	Because I want to learn clojure, so for a practice I was writing a polynomial solver which needs the read the polynomials from in?
17:19	amalloy	Somelauw: my point was you weren't trying out repeatedly; you were just writing anonymous functions that can't be called
17:19	amalloy	reading polynomials from in is great, knock yourself out
17:22	raek	Somelauw: you might be interested in this: http://groups.google.com/group/leiningen/browse_thread/thread/f9f9ed97eb8a2928/ccab95588ef50d05
17:22	raek	oh, (read-line) works fine in lein repl... ignore that...
17:27	Somelauw	What is the best way to debug. When simply running it, it does show exceptions, but no linenumbers.
17:29	raek	if you (re)load the namespace with (requie 'the.namespace) or (require 'the.namespace :reload), line numbers should be there
17:32	raek	if you use emacs, swank-cdt is worth checking out: http://georgejahad.com/clojure/swank-cdt.html
17:32	Somelauw	I don't really understand. I am using cake, but I am running this script standalone.
17:33	Somelauw	i use vim, unfortunately
17:34	Somelauw	But I will remember swank-cdt for when I ever convert.
17:35	Somelauw	But I think cdt can also be ran standalone.
17:40	raek	It's probably easier to get line numbers if you develop in a project. (This is what I am used to, but perhaps there is a cleaver way to it with clojure scripts with cake too.)
18:20	amalloy	is there a list somewhere of the easily-available ring middlewares? i find myself wanting to write one, but it's pretty simple and i don't know how to find out if it exists already
18:24	dakrone	amalloy: https://github.com/mmcgrana/ring/wiki/Libraries has some
18:26	amalloy	thanks dakrone
18:46	mec	Is there anything to check if something is Seqable?
18:49	mec	Something like (seq x) that wont throw an exception on (sec 5)
18:52	amalloy	mec: (coll? x) comes close
18:54	mec	im actually kind of surprised seq throws an exception instead of just returning nil
19:00	mec	i guess ill just have to (try (seq x))
19:17	TimMc	,(empty? 5)
19:17	clojurebot	java.lang.IllegalArgumentException: Don't know how to create ISeq from: java.lang.Integer
19:17	TimMc	fascinating
19:18	dnolen	,(instance? clojure.lang.Seqable 5)
19:18	clojurebot	false
19:19	dnolen	mec: ^
19:19	dnolen	,(instance? clojure.lang.Seqable [])
19:19	clojurebot	true
19:20	mec	,(instance? clojure.lang.Seqable (to-array [1 2 3]))
19:20	clojurebot	false
19:20	mec	,(seq (to-array [1 2 3]))
19:20	clojurebot	(1 2 3)
19:25	amalloy	same for String and the other types the runtime secretly makes seqable
19:27	mec	ya thats why it surprises me theres no parallel seq? function
19:28	amalloy	mec: seqable, you mean. seq? exists and doesn't do what you want
19:28	mec	i mean seq? doesnt parallel seq
19:38	dnolen	mec: ah yeah, a thought define a protocol like ISeqable, extend-type on the primitive array types, extend-protocol ISeqable to clojure.lang.Seqable
19:39	dnolen	mec: did a quick test and it seems to work and would be fast.
19:40	mec	faster than (try (seq x)) ?
19:40	amalloy	mec: for sure
19:40	amalloy	nothing is slower than try/catch :P
19:40	mec	i thought try/catch was just a label and a goto
19:41	amalloy	no
19:41	mec	maybe thats why my implementation of multiple-value-bind was so slow, binding has a try/finally in there
19:42	amalloy	it has to handle nonlocal exceptions: if seq calls something that calls something that throws an exception, the stack has to be smart enough to come back to you
19:42	dnolen	mec: creating an exception object is slow, you want to create one exception instance and reuse it if you're going to do control flow things.
19:42	amalloy	that too. creating an exception snapshots the stack
19:42	mec	ah
19:56	TimMc	,(coll? nil)
19:56	clojurebot	false
20:01	TimMc	So, the set of things that it is safe to call seq on: nil, and anything that coll? approves?
20:02	amalloy	TimMc: no. like i said, it only gets you close
20:02	amalloy	&((juxt coll? seq) "test")
20:02	sexpbot	⟹ [false (\t \e \s \t)]
20:02	TimMc	blerg, right
20:03	TimMc	,(coll? (seq "foo"))
20:03	clojurebot	true
20:05	TimMc	So... there's no seqable? function?
20:06	dnolen	TimMc: mostly likely because it would be a slow test, many things are seqable. Thus my above idea.
20:08	mec	if only seq didnt throw an exception :x
20:10	amalloy	mec: that's a bad idea. having seq be slow would be a lot worse than having a slow seqable? function available
20:10	amalloy	TimMc: i think there's one in contrib, somewhere
20:16	mec	amalloy: what do you mean seq be slow?
20:16	amalloy	mec: if seq checked for seqable-ness to return nil instead of throwing an exception it would be slow
20:17	mec	not really, its a giant if statement, and if it gets to the end it throws an exception, so just return nil instead
20:17	mec	https://github.com/clojure/clojure/blob/master/src/jvm/clojure/lang/RT.java#L462
20:17	amalloy	hm
20:18	amalloy	but
20:18	amalloy	then how could you tell (seq 5) from (seq nil) or (seq [])
20:26	mec	thats the point, right now (seq 5) throws an exception so the only way to check is try/catch
20:29	amalloy	mec: and if you made (seq 5) return nil, there would be no way at all to check
20:30	amalloy	you'd make your particular use-case more convenient, for sure
20:32	mec	beats having to do this https://gist.github.com/950133
20:32	dnolen	mec: to slow for a predicate I would think, you could implement my solution (which seems fine to me) and bring it up on the clojure-dev list.
20:39	amalloy	if you were going to write it that way, mec, you could at least do (or (nil? x) (-> x class .isArray) (some #(instance? % x) [clojure.lang.ISeq...]))
20:50	dnolen	mec: https://gist.github.com/950144
20:51	dnolen	this test can be run 1e8 times in ~380ms
20:52	dnolen	needs to extend to the arrays o' course
21:01	mec	how would you extend for arrays?
21:16	mec	,(clojure.lang.ArraySeq/createFromObject (to-array [1 2 3]))
21:16	clojurebot	java.lang.IllegalArgumentException: No matching method: createFromObject
21:16	mec	,(show clojure.lang.ArraySeq)
21:16	clojurebot	java.lang.Exception: Unable to resolve symbol: show in this context
21:21	mec	dnolen: wow thats a lot faster than how clojure.core does seq
22:11	cemerick	This is totally off-topic, but I just laughed so hard at this I can't help but… http://lgv.s3.amazonaws.com/AmazonFail_explainedByEmployee.jpg