#clojure – 2011-08-20

2011-08-20

00:00	srid	eg: here's the most voted question with [clojure] tag asked last week, http://stackoverflow.com/questions/7064389/
01:58	dabd	I did require [incanter.core :as i] but when I try to load a file in the repl it says Could not locate incanter/core__init.class or incanter/core.clj on classpath:
02:01	dabd	I pulled the deps with lein deps I don't know why it cannot find incanter.core
02:01	dabd	any ideas?
02:47	srid	'lein new' generates a basic project layout; are their alternative layouts? eg: a command-line project with opt parser and such.
02:50	Pupeno	srid: there might be plugins for that, lein-noir for example generates a web app by lein noir new, but it's not really an alternative layout, just another task.
02:51	amalloy	i don't know about lein, but cake lets you store project templates in ~/.cake, and you can specify which template to use when you new one up
02:51	ibdknox	srid: I've thought about potentially making a general purpose project template plugin
02:51	ibdknox	I actually thought someone had
02:51	srid	something like python's pastetemplate
02:51	ibdknox	though I can't remember what it's called now
02:52	srid	i don't seem to find it in https://github.com/technomancy/leiningen/wiki/Plugins either.
02:54	ibdknox	ah
02:54	ibdknox	here it is
02:54	ibdknox	https://github.com/levand/spawn
02:55	Pupeno	In a lein plugin I'm writing, I'm doing (eval-in-project project `(do (require 'lobos.config) (println lobos.config/db))) but it fails saying that lobos.config can't be found. But it's there, lein repl and (require 'lobos.config) works. What am I missing?
02:56	amalloy	&`'lobos.config
02:56	lazybot	⇒ (quote lobos.config)
02:56	amalloy	k, just testing
02:57	srid	what is the currently fashionable way to get a clojure app running on appengine? there are a quite a few, eg: https://github.com/sethtrain/beget
02:58	srid	ah, i'm beginning to feel eye strain and head ache ... must get some sleep!
02:59	ibdknox	srid: here's the relevant noir post
02:59	ibdknox	about appengine
02:59	ibdknox	https://groups.google.com/d/topic/clj-noir/5a-3mYzs8dA/discussion
03:01	Pupeno	srfixed.
03:01	Pupeno	srid: fixed.
03:02	amalloy	hah, the hidden dangers of tab completion
03:51	MasseR	Is anyone of you using slimv? Has the cw command changed for you?
04:09	babilen	MasseR: I use it for paredit (and vimclojure for the rest) -- The cw command works as expected.
04:16	MasseR	babilen: Normally cw deletes a word until space. Now it removes the space too
04:17	babilen	MasseR: I know, but as I said: It is working as expected here.
04:18	MasseR	So you still get the behaviour, but it's something you want?
04:20	babilen	If "this behaviour" == "deletes the space" then no. cw behaves as it should and does everywhere else.
04:26	MasseR	Ok
04:32	Pupeno	In a lein plugin I can do (require 'lobos.config) but when I do (println lobos.config/db) I get an error which, as usual, doesn't help at all (Exception in thread "main" java.lang.ClassNotFoundException: lobos.config (NO_SOURCE_FILE:1)). It doesn't mention lobos.clj anywhere in the stack trace, which is the only file in the lein plug in. Any ideas what's going on?
05:33	Netpilgrim	Hi. I'm still in the process of learning the basics. Are there cases where (some_map k) and (some_set e) instead of (get some_map k) and (contains? some_set e) don't work? And which versions are considered more ideomatic/better style?
05:34	Netpilgrim	s/ideomatic/idiomatic/
05:34	lazybot	<Netpilgrim> Hi. I'm still in the process of learning the basics. Are there cases where (some_map k) and (some_set e) instead of (get some_map k) and (contains? some_set e) don't work? And which versions are considered more idiomatic/better style?
05:35	Netpilgrim	Cool feature. I didn't know the bot would do that. :)
06:05	thorwil	Netpilgrim: i'm not even aware of (get some_map k), while (some_map k) is common
06:12	thorwil	Netfeed: oh, and contains? will evaluate to true or false, not deliver an element or nil
06:12	Netpilgrim	thorwil: OK, thanks. I thought that the shorter variant is probably more widespread but to me as a beginner the longer form looks more readable. It's probably just a matter of getting used to the syntax.
06:13	Netpilgrim	thorwil: I know that (contains? s e) is not a replacement for (s e) but it works the other way around.
06:15	Netpilgrim	thorwil: The use of (s e) for conditions also seems consistent with a somewhat similar case I've read somewhere, namely using (seq coll) instead of (not (empty? coll)).
06:16	thorwil	the (:k m) and (m :k) is certainly one of the things you have to know, but once you do, it makes for lovely concise code.
06:18	Netpilgrim	thorwil: The (m :k) variant is probably better because it works with all datatypes as keys?
06:19	thorwil	Netpilgrim: i actually keep forgetting that both orders do not work for all cases, as most of the times i only have keywords :)
06:20	Netpilgrim	thorwil: Thanks for your input.
09:34	dabd	If you change project.clj by adding a new depency do you have to stop the swank server and run lein swank again or there is another way? lein deps seems to not work because I get class not found error when loading a source file containing a require from the new dependency.
09:41	tufflax	I think lein deps, then restart swank should work, if not check spelling :P
13:01	schlechtv	How can I make this not fail: (use clojure.contrib.strint) (def tmplt "Here is a silly string with a number ~(int x)") (let [x 5] (<< tmplt))
13:22	dnolen	so anyone use Erlang bit pattern matching much?
13:32	KirinDave	In erlang?
13:32	KirinDave	Yes.
13:32	KirinDave	It's frikkin' amazing and Erlang programmers love it.
13:33	KirinDave	You haven't really enjoyed writing streaming byte protocol code until you've done it in Erlang and realized your code actually is fairly descriptive of the binary protocol.
13:33	dnolen	KirinDave: so I'm think doing the same thing in match would be trivial.
13:34	dnolen	KirinDave: do you have any public code lying around where you've used it? I've looked over the Erlang syntax but curious to see some real examples.
13:34	KirinDave	Uhhh….
13:34	KirinDave	I actually don't have any public code
13:35	KirinDave	It was custom protocol stuff for powerset.
13:35	KirinDave	Sorry!
13:41	dnolen	np, should be fun in Clojure.
13:59	robonobo	hi guys
14:00	robonobo	does the fact that some results are seqs and others are vectors in the unittests for http://4clojure.com/problem/39#prob-title seems strange to anyone?
14:05	opqdonut	yeah, but:
14:05	opqdonut	,(= [1 2 3] '(1 2 3))
14:05	clojurebot	true
14:43	belun	hello.
14:43	belun	know any small well writen open source java projects that i could write in clojure ?
14:43	belun	as in translate
14:44	belun	(for fun)
14:44	tufflax	why don't you solve a new problem instead? :p
14:45	belun	must not be bothered with the details
14:45	belun	of business
14:45	belun	logc
14:45	tufflax	of business?
14:46	belun	um... what the app does
14:46	belun	business logic
14:47	jli	dnolen: are you working on bit patterns for match?
15:07	csquared	howdy guys — i'm having a real tough time setting a response cookie using compojure
15:07	csquared	docs are kind of thin
15:07	csquared	can anyone point me to an example?
15:07	csquared	or how i would add a cookie to this line?
15:07	csquared	(-> (response "You're in!") (status 200))
15:08	csquared	i've got the route wrapping it (wrap-cookies)
15:08	csquared	fyi i'm a clojure n00b as well : \|
15:10	mdeboard	think most people are :P
15:10	csquared	heh
15:10	csquared	yeah i was working with a friend and doing OK with passing back the hash maps
15:10	csquared	then this "->" thing showed up
15:11	csquared	i think i just need to get a :cookies key into the reponse
15:11	mdeboard	that's actually a really awesome macro ;)
15:11	csquared	not knocking it
15:11	csquared	it just took things out of my level of understanding atm
15:11	csquared	i know its the "threading marco"
15:11	mdeboard	yeah i'm not real familiar with using HTTP in Clojure,so I can't help :(
15:12	csquared	maybe we can help me understand that line though
15:12	csquared	or what its doing?
15:12	csquared	or just a link to a doc?
15:12	csquared	i've been googling "clojure ->"
15:13	csquared	ok Other macros re-arrange forms in useful ways, like the -> macro, which recursively inserts each expression as the first argument of the next expression:
15:14	tufflax	csquared u got it now? :p
15:14	csquared	so its kinda of like an inject?
15:14	csquared	i'm thinking it need an (assoc :cookies …) at the end
15:14	tufflax	,(-> 2 - str)
15:14	clojurebot	"-2"
15:15	tufflax	same as (str (- 2))
15:15	tufflax	,(-> 2 (- 5) (str "!"))
15:15	clojurebot	"-3!"
15:16	csquared	,(-> {:body ""})
15:16	clojurebot	{:body ""}
15:16	tufflax	same as (str (- 2 5) "!")
15:17	tufflax	it doesn't do anything with just 1 argument :p
15:17	csquared	,(-> {:body ""} (assoc :cookies {:name "cookie-value"}))
15:17	clojurebot	{:cookies {:name "cookie-value"}, :body ""}
15:18	csquared	this looks promising
15:18	csquared	also, clojurebot is aweseom!
15:18	tufflax	hehe
15:18	csquared	HOLY SHIT IT WORKED!
15:18	tufflax	,(doc ->)
15:18	clojurebot	"([x] [x form] [x form & more]); Threads the expr through the forms. Inserts x as the second item in the first form, making a list of it if it is not a list already. If there are more forms, inserts the first form as the second item in second form, etc."
15:18	csquared	thanks gentlemen!
15:18	csquared	or ladies
15:19	tufflax	no problem :)
15:19	belun	or bots
15:19	csquared	lol shouldn't always assume CS people are men...
15:19	csquared	hahah
15:19	csquared	turing test FTW
15:20	csquared	fyi this is what worked:
15:20	csquared	(-> (response "You're in!") (status 200) (assoc :cookies {:name "value"}))
15:21	tufflax	,(doc ->>)
15:21	clojurebot	"([x form] [x form & more]); Threads the expr through the forms. Inserts x as the last item in the first form, making a list of it if it is not a list already. If there are more forms, inserts the first form as the last item in second form, etc."
15:21	tufflax	If you ever need it :p
15:38	dnolen	jli: yes
16:04	srid	where do people generally host their Clojure web apps?
16:08	chouser	srid: I've used heroku, looked at CloudBees and heard about ways to use Google's appengine
16:18	ibdknox	srid: EC2
16:18	ibdknox	srid: Heroku and elastic beanstalk are probably the easiest
16:18	ibdknox	beanstalk is significantly cheaper
16:39	srid	i'll go with appengine for now.
16:40	srid	what would be the rake-like tool for clojure?
16:40	srid	ruby's rake or node's cake
16:43	amalloy	srid: cake and lein are the main tools for that
16:44	srid	there doesn't seem to be a obvious way to define tasks in lein, but there is apparently in cake: http://stackoverflow.com/questions/3906276/whats-the-difference-between-cake-and-leiningen
16:47	patchwork	It's easy to add tasks to lein. You create a src/leiningen/command.clj with a function named "command" and you can call it from the command line:
16:47	patchwork	> lein command
16:47	hsbot	Not in scope: `lein'Not in scope: `command'
16:47	patchwork	oops, triggered evaluation
16:47	patchwork	what is this hsbot? I am new to the channel
16:47	amalloy	haskell
16:48	patchwork	ah nice!
16:48	amalloy	nobody knows why he hangs out in here
16:48	amalloy	$heval [1..5]
16:48	lazybot	⟹ [1,2,3,4,5]
16:48	amalloy	especially since lazybot does haskell too
16:49	patchwork	is there a clojurebot as well?
16:50	srid	$(+ 2 3)
16:50	amalloy	,(inc 2)
16:50	clojurebot	3
16:50	amalloy	&(inc 2)
16:50	lazybot	⇒ 3
16:50	srid	$pyeval raise SystemExit
16:50	srid	heh
16:51	patchwork	we're still here
16:52	patchwork	,(defn yoyo [a] (* a 3))
16:52	clojurebot	#<Exception java.lang.Exception: SANBOX DENIED>
16:53	patchwork	aha
16:53	srid	patchwork: can't find docs for writing command.clj in lein docs; is there a sample?
16:55	srid	wait, should the actual command name be in the filename (command.clj) or in the function name?
16:55	patchwork	srid: not sure where I found it, but I have a couple of commands in my project
16:56	patchwork	it should be a command named "command" in a file called command.clj
16:56	patchwork	or better yet, the function name should have the same name as the file
16:56	srid	so if I want to have a command called "lein serv" - i should create a function called "serv" in src/leiningen/serv.clj?
16:56	patchwork	Yep
16:57	patchwork	that works for me at least
16:58	coopernurse	srid: yep. note that you can also dispatch on a 2nd argument if you want to support sub-commands from a single lein plugin. e.g. lein ring uberwar
16:58	srid	$ lein serv 1 ↵
16:58	srid	Exception in thread "main" java.lang.Exception: No namespace: leiningen.serv found (NO_SOURCE_FILE:0)
16:58	srid	oops; sorry for the whitespace.
16:59	coopernurse	as an example of a working plugin, take a look at: https://github.com/weavejester/lein-ring/blob/master/src/leiningen/ring.clj
16:59	coopernurse	srid: what dir are you executing lein in? I assume the project dir that contains your 'src' dir?
17:01	srid	correct; the error was due to my forgetting to include a (ns ...) statement.
17:01	coopernurse	ah
17:01	patchwork	so it worked then?
17:01	srid	yes, worked for a simple `println` function.
17:03	srid	the slow startup time of java apps seems annoying.
17:04	coopernurse	yeah, jvm startup time is rough on lein. but for regular development you can write code in the REPL
17:06	srid	,#'foo
17:06	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve var: foo in this context, compiling:(NO_SOURCE_PATH:0)>
17:07	amalloy	you can also start a lein shell, which is supposed to reduce startup time pain
17:07	patchwork	so, I am having a problem with exceptions using postgres through jdbc
17:07	coopernurse	amalloy: ah, didn't know that.. good to know
17:07	patchwork	whenever something goes wrong with the db call, I get something like this:
17:07	amalloy	lein int
17:07	patchwork	java.lang.Exception: Call getNextException to see the cause.
17:08	patchwork	but when I try to call (.getNextException e)
17:08	patchwork	I can't, because it is not a SQLException?
17:09	patchwork	I feel like the jdbc library is throwing everything up as java.lang.Exception, even if it is a java.sql.SQLException
17:09	coopernurse	patchwork: try (.getCause e)
17:09	patchwork	so that I can't find out what the actual problem was
17:09	coopernurse	haven't tried it, but that should give you the next exception down
17:09	patchwork	coopernurse: thanks, I'll try that
17:10	patchwork	coopernurse: Aha, so I need to say (.getNextException (.getCause e))
17:10	patchwork	the cause is the sqlexception
17:10	patchwork	not the original one
17:10	coopernurse	patchwork: ah, there you go
17:11	patchwork	thank you much
17:11	patchwork	wrestling with that one for awhile
17:13	coopernurse	no problem - error message was misleading
17:13	srid	I can't seem to specify https://github.com/clojure/tools.cli as a dependency in project.clj; `lein deps` cannot find it. is it because, tools.cli was never uploaded to clojars.org?
17:17	coopernurse	srid: yeah, looks like it's not in clojars
17:18	coopernurse	you could try clojure.contrib.command-line instead - http://clojuredocs.org/clojure_contrib/clojure.contrib.command-line/with-command-line
17:18	amalloy	clojure/core stuff never goes on clojars, does it?
17:20	coopernurse	amalloy: oops, good point
17:20	amalloy	to be fair, i checked too
17:21	coopernurse	I don't see it bundled in 1.2. Perhaps it's a 1.3 addition?
17:23	srid	wasn' clojure.contrib.command-line replaced with tools.cli?
17:25	raek	the official clojure libs are not usually on clojars, but in some other repo
17:30	srid	how would I then define tools.cli as a dependency to be fetched via 'lein deps'?
17:32	srid	found it http://mvnrepository.com/artifact/org.clojure/tools.cli -- [org.clojure/tools.cli "0.1.0"]
17:36	polypus74	i haven't looked into this in over six months. any news on the async http front? what would currently be the best way of doing websockets in clojure?
17:37	srid	amalloy: 'lein shell' doesn't work; shell is not a command.
17:37	amalloy	lein int
17:38	amalloy	polypus74: aleph has websockets, doesn't it?
17:39	polypus74	amalloy: i believe it does, was just wondering if there had been any more recent developments. there is a branch of ring with async, but it doesn't look like it's moved much. was hoping for some simple solution i could just drop into a regular ring app. maybe ontop of jetty or even netty
17:40	polypus74	aleph might just be the way to go though
17:47	coopernurse	is there any equivalent to (time) that monitors heap usage? I want to do some crude memory profiling of my code.
17:49	coopernurse	now that I ask that aloud I'm not sure exactly how it would work. perhaps just return heap size delta before/after the inner function executes..
17:49	coopernurse	looks like I could roll my own using java's Runtime class
17:53	srid	interesting, clojure core doesn't include a http client, and I need to use clj-http.
17:54	amalloy	coopernurse: so long as you don't mind that gc will generally not happen right away, so heap size will continue to go up even if you've discarded all the temporary objects you allocated
17:54	coopernurse	right
17:54	coopernurse	perhaps you could run gc manually
17:54	coopernurse	before/after
17:55	amalloy	depends on what you want to measure
17:55	amalloy	if you care about churn, then don't gc; you can see how much was allocated during the run
17:55	amalloy	if you care about depletion, then you want to see if the function uses any "permanent" memory
17:58	coopernurse	right.. and of course, if it does anything non-trivial, gc will get run concurrently, making it hard to measure
18:02	amalloy	yep. that's what profilers are for
18:04	amalloy	but getting out something as fine-grained as you want will probably be hard
18:08	coopernurse	yeah, well, this gives me an excuse to learn how to write a macro, even if it's a useless one :-)
18:09	srid	apparently clj-http seems to be unmaintained.
18:20	memothy	Hello everyone. I've never used Clojure before, but I'm familiar with java and scheme. I'm just starting to feasibility-test some algorithms for the android platform. REPL sounds appealing for quick and dirty prototyping, but I'd like to make sure that I'm barking up the right tree here.
18:22	memothy	With Clojure coupled to the jvm, can I integrate numeric libraries from java trivially, or are some sort of bindings required?
18:26	memothy	And poking around online, I noticed someone complaining that Clojure paused an android device for ~10s before necessary bootstrapping code loaded. While I would ultimately remove Clojure from the final result, after this bootstrap process would benchmarks run on an android device approximate performance in a pure java setting (and maybe even provide worst case performance data)?
18:30	memothy	I'm just starting to read `the joy of Clojure', but as I said, I'd like to know whether the language is suitable as a prototyping language. I anticipate quick prototypes that use the same libraries that I would later incorporate into a pure java project hosted on the android platform.
18:37	coopernurse	memothy: you can invoke java libs directly from clojure without bindings
18:37	coopernurse	so it should be suitable for prototyping java apps
18:39	coopernurse	example of calling java swing classes from clojure w/o clojure specific bindings: http://clojure.org/jvm_hosted
18:39	memothy	sweet. do you know of any performance data comparing java performance to clojure performance under different numeric (and maybe string) libraries?
18:40	coopernurse	hmm.. I'm aware of this site: http://shootout.alioth.debian.org/
18:41	coopernurse	which has general language benchmarks.. java and clojure are represented
18:41	coopernurse	but I'm not sure if that's what you're after
18:45	memothy	at a glance the testing schema is confusing ('fastest program versus fastest program'...huh?). but if I'm calling without bindings, then I imagine that performance under Clojure reflects worst case performance under java. that's a sufficient condition at least, right?
18:46	polypus74	memothy: note links under performance bullet here: http://disclojure.org/2011/08/15/today-in-the-intertweets-aug-15th-ed/
18:48	coopernurse	yes, it's hard to speak precisely, but clojure compiles your .clj source to jvm bytecode, just like javac would for .java source. so it sort of comes down to your implementations in the two languages
18:48	coopernurse	my guess is if you profiled the swing example I linked to above and compared it to the same code in java, the resulting byte codes are probably similar
18:49	coopernurse	since the clojure code is written in a largely imperative style, and is just invoking java classes for the most part
18:49	coopernurse	but if you compared solutions to a mathematical problem, say a project euler problem
18:50	coopernurse	then the code you'd write in clojure vs java would likely be really different, so the resulting bytecode would be quite different too
18:51	Netpilgrim	I'm trying to get the hang of seqs. What is the rationale behind (seq '()) being nil when there are in fact empty seqs like the return value of (rest '())?
18:52	memothy	so writing solutions within the idioms of each language, performance is a toss-up, but so long as I'm simply filling java data structures and operating on them with java libraries, then I can expect similar performances, yeah?
18:53	memothy	And thanks polypus74 for that I link. I'll probably be exploring that domain in general, as well.
18:54	coopernurse	memothy: I suspect that's right. if you used clojure as a tool to script java libraries, I suspect you'd get pretty similar perf -- but perhaps with some reflection overhead. there are some type hints you can throw in to help the clojure compile avoid reflection
18:55	coopernurse	you mentioned android
18:55	memothy	Well thanks, coop. I'm off to the library. In a month or so I ought to have some results specifically on Clojure as a java prototyping tool.
18:56	memothy	Oh, yeah.
18:56	coopernurse	I'm not sure how the dalvik vm compares, or how jvm bytecode is translated to run on dalvik
18:56	coopernurse	so that may introduce some differences, not sure
18:57	coopernurse	to clarify: the converted bytecode written in clojure should work (folks have written android apps in clojure) but I'm not sure if it changes the perf profile at all
18:58	memothy	My motivation for ultimately working with Clojure--I figure if I use the same libraries that I will eventually use in my project, then the coding should be much cleaner (and anything but Octave/MatLab for prototyping).
18:59	memothy	Of course I'll research it better before I throw away my prototypes and code the project's core, but I already have sufficient motivation to learn Clojure as a prototyping tool.
18:59	coopernurse	memothy: makes sense. it's definitely a fun language to learn
19:00	memothy	I'm sure I'll eventually find my way back to that ~10s claim, but for now I feel comfortable proceeding.
19:00	coopernurse	REPL makes experimentation way faster
19:00	memothy	Thanks for the help. I'll probably become a regular around here, so I'll see you around.
19:01	coopernurse	cool, see you
19:36	chewbranca	anyone have a recommendation for a reliable http request clojar?
19:37	chewbranca	everytime I come back to clj-http something different has happened, and now the getwoven repo is gone
19:43	ibdknox	technomancy: ping
20:44	srid	chewbranca: i wonder if there is even an alternative http lib.
20:45	srid	i was battling with myself as to writing a gzip decompress code in clojure to decode a gzip encoded http response. my java knowledge seems insufficient.
20:57	chewbranca	srid: yeah I dealth with the same thing a few months ago, the getwoven/clj-http had a bug in it breaking gzip responses, and hadn't been updated in quite a while, so I found a fork that fixed the gzip issue but wasn't on clojars, then I saw a few months ago that get-woven brought in the pull requests fixing things, now the repo is gone :/
20:57	chewbranca	srid: let me see if I can find that fork that worked, just a sec
20:59	srid	getwoven doesn't have a clj-http repo
20:59	chewbranca	srid: heh.. yeah that's my point
20:59	srid	clj-http doesn't seem be maintained; there are a bunch of pull requests here without any update - https://github.com/mmcgrana/clj-http/pulls
20:59	chewbranca	srid: getwoven created clj-http, repo is no longer there
21:00	srid	28 forks, but only 5 people watching?
21:00	srid	that's strange, usually more people watch a repo with less forks.
21:02	srid	C was my first programming language, and whilst learning it (2001) I remember spending whooping two hours just to write a program to print the multiplication table. something like that is happening with me when writing Clojure. :-)
21:03	chewbranca	srid: haha clojure is good times, really enjoying working with it
21:15	zmaril	How does one go about creating an infinite sequence?
21:19	srid	,(iterate inc 1)
21:19	clojurebot	(1 2 3 4 5 ...)
21:22	wastrel	clojurebot, botsnack
21:22	clojurebot	Thanks! Can I have chocolate next time
21:23	joshuahickman	Where precisely did clojurebot come from?
21:23	joshuahickman	I know he can do code eval and such
21:23	joshuahickman	And it seems every time I visit I see a new thing someone programmed him to do
21:23	joshuahickman	Which is to say, is he open source?
21:24	joshuahickman	On a more clojure related note:
21:25	joshuahickman	#() syntax macroexpands, it seems, to (fn [%] ...), but does not make a function literal at compile time
21:25	joshuahickman	I presume this is for simplicity's sake?
21:26	wastrel	i sure don't know
21:26	wastrel	re clojurebot
21:26	joshuahickman	Because it confused me right good earlier
21:27	joshuahickman	Oh, yeah :)
21:27	joshuahickman	That #() confused me earlier, because I did a
21:27	joshuahickman	(-> 2 #(+ 2 %))
21:27	joshuahickman	Basically
21:27	wastrel	i dunno from clojure either :]
21:28	joshuahickman	And I thought it would work, not unreasonably, imo
21:28	srid	could somebody explain why I keep getting "Not in GZIP format" error when gzip decompressing a gzip-encoded HTTP response? here's the code: https://gist.github.com/1159952
21:29	srid	i'm pretty the implementation of gzcat is ugly. just trying to get something working first.
21:29	srid	*pretty sure
21:30	zmaril	srid: thanks. I was trying to do a prime list and I was trying to think of the right question to ask. It works sort of now: https://gist.github.com/1159955
21:30	joshuahickman	I might be looking at old docs, but it seems like that read function might take more arguments
21:38	srid	client/get returns String; shouldn't that be Bytes?
21:38	srid	maybe that's why the original gzipped bytes are lost.
21:39	srid	note my use of (.getBytes string) -- I believe that uses utf16, and unicode makes no sense with bytes.
21:48	toast`	ah, so you got ascii -> unicode string -> utf16le bytes… yeah, that's not an identity
21:50	tufflax	josh what did you think would be the result of (-> 2 #(+ 2 %))?
21:50	tufflax	joshuahickman
21:50	joshuahickman	2
21:50	joshuahickman	*4
21:50	joshuahickman	THAT WAS A TYPE
21:50	joshuahickman	*TYPO
21:50	joshuahickman	Wow
21:50	joshuahickman	I am not actually stupid
21:50	tufflax	lol
21:50	joshuahickman	I wish to convey this
21:50	tufflax	lol
21:51	tufflax	why 4? i mean, it doesn't give the previous result as an argument, it simply inserts it into the next form
21:51	joshuahickman	Yeah, I was anticipating I would get a function literally just like (-> :a {:a 4})
21:52	darevay	Question: there's a saying something like "write code that shows how to solve the problem, not what to do", or something like that. Anyone got a reference or at least, less mangled quote?
21:52	joshuahickman	Yeah, but when I put a symbol (as in, not a list), it applies that to the previous argument
21:53	tufflax	no
21:53	joshuahickman	Perhaps I'm not articulating
21:53	tufflax	it builds a list and puts it second
21:53	joshuahickman	Yeah
21:53	joshuahickman	It does this for all non-lists
21:53	tufflax	it has nothing to do with arguments, just with putting things in lists
21:54	joshuahickman	Yeah, I understand that's how it's implemented
21:54	joshuahickman	I'm just saying it violated expectations because it looks like a literal syntax
21:54	joshuahickman	Like sets and maps
21:54	joshuahickman	It does not look like a macro
21:54	joshuahickman	Does that make sense as a reaction?
21:54	joshuahickman	Perhaps I am insane
21:55	dnolen	,(-> 2 (+ 2))
21:55	clojurebot	4
21:55	tufflax	you mean #() looks like literal syntax?
21:56	joshuahickman	The example I was actually trying to do was #(.split % "\\.") , but that's neither here nor there
21:56	joshuahickman	It does
21:56	joshuahickman	I anticipated it resolving, at compile time, to an object
21:56	joshuahickman	Although it being a closure might make that tricky
21:56	joshuahickman	I was just curious if this is something people had thought about
21:58	dnolen	,(-> "foo.bar" (.split "\\.") vec)
21:58	clojurebot	["foo" "bar"]
21:58	tufflax	But -> does not handle objects, it handles syntax. And so, if #(+ 2 %) counted as a list, it would have become #(+ 2 2 %), and if it would #() would expand first then, (fn 2 [%] (+ 2 %)), neither of which is 4
21:59	tufflax	but maybe you got that already :p
21:59	joshuahickman	Yeah, I noticed it was the second one
21:59	joshuahickman	Which, by the by, has one of the more confusing compile errors until I got it
21:59	dnolen	joshuahickman: the problem is not #(), it's ->
21:59	tufflax	hehe
22:00	joshuahickman	See, dnolen, it depends on what you think the problem is
22:00	joshuahickman	I just changed it to (.split ""), but I was actually hoping the #() syntax acted more like {}
22:00	joshuahickman	Where it is not a list at all
22:01	dnolen	joshuahickman: what I mean is, you don't understand -> does. if you do, you know you don't need #()
22:01	joshuahickman	And then -> makes it into (#() xxx)
22:01	joshuahickman	Not in this case, no, but when I saw that I got curious, is all
22:01	tufflax	oh now i see what you mean
22:01	joshuahickman	I would prefer you not assume I don't know how these things work
22:02	tufflax	when you said object i though you ment like
22:02	tufflax	,+
22:02	clojurebot	#<core$_PLUS_ clojure.core$_PLUS_@1cd022c>
22:02	dnolen	joshuahickman: I'm not assuming anything.
22:02	tufflax	I misunderstood you josh :p
22:03	joshuahickman	Yeah, I was just pondering why the #() reader macro is the only one that doesn't output an object
22:04	joshuahickman	I mean, {} could easy expand to (make-map key val key val)
22:04	joshuahickman	But it doesn't
22:04	joshuahickman	That's all I was thinking
22:04	tufflax	I see
22:05	tufflax	well, object is a very vague term here i think :p
22:05	joshuahickman	That's true enough
22:05	joshuahickman	I suppose I mean not a list
22:05	dnolen	,(macroexpand '(-> foo #()))
22:05	clojurebot	(fn* foo [] ())
22:05	joshuahickman	Clojure is really my first lisp where there are semantically meaningful non-list compile time constructs, so excuse the vagueries
22:06	ibdknox	dnolen: sadly it appears I can't do the cljs-watch stuff as a leiningen plugin
22:06	dnolen	ibdknox: darn.
22:06	ibdknox	dnolen: since it would require lein to run as 1.3.0
22:07	ibdknox	I did, however, get it as a single shell script
22:09	dnolen	,(macroexpand '(-> foo (#())))
22:09	clojurebot	((fn* [] ()) foo)
22:11	joshuahickman	yes, precisely
22:11	joshuahickman	,(macroexpand '(-> :a #{:a}))
22:11	clojurebot	(#{:a} :a)
22:12	joshuahickman	,(macroexpand '(-> :a {:a :b}))
22:12	clojurebot	({:a :b} :a)
22:12	dnolen	,(-> :a #{:a})
22:12	clojurebot	:a
22:12	joshuahickman	Right
22:12	dnolen	,(-> :a {:a :b})
22:12	clojurebot	:b
22:12	dnolen	,(-> {:a {:b {:c 1}}} :a :b :c)
22:12	joshuahickman	But you see how the macroexpansions I just did behave differently than the one for #()?
22:12	clojurebot	1
22:13	joshuahickman	The one for #() doesn't wrap in a list because the #() produces a list, not an IFn
22:14	dnolen	,(macroexpand '(-> 0 (for [x (range 10)] x)))
22:14	clojurebot	#<ExecutionException java.util.concurrent.ExecutionException: clojure.lang.ArityException: Wrong number of args (3) passed to: core$for>
22:15	dnolen	it's no different for anything else that would expand.
22:15	joshuahickman	Yes, but it should be different, and it should be different in the same way {}, [], and #{} are
22:16	joshuahickman	This is the purpose of literal syntax
22:16	tufflax	well josh here http://clojure.org/reader the data structures are under "reader forms" while # without { following are under "macro characters", but yeah... :p
22:17	tufflax	is*
22:17	dnolen	joshuahickman: except #() is not literal syntax. It's sugar. fn is the literal syntax.
22:17	joshuahickman	according to the link above:
22:17	joshuahickman	Anonymous function literal (#())
22:17	joshuahickman	But I see your point
22:18	joshuahickman	I mean, the regexes seem to be literals, too
22:19	dnolen	joshuahickman: #() is listed under the real list of literals. but yes, that's a bit confusing.
22:19	dnolen	s/is/is not
22:19	lazybot	<dnolen> joshuahickman: #() is not lis notted under the real lis nott of literals. but yes, that's a bit confusing.
22:19	dnolen	erg
22:19	joshuahickman	But regexes aren't either
22:19	tufflax	:p
22:19	joshuahickman	yeah
22:19	joshuahickman	But regexes work this way, albeit less usefully for ->, as they aren't IFn, as far as I know
22:20	lobotomy	haha, lazybot does s/foo/bar/g when someone says s/foo/bar?
22:20	lobotomy	bug spotted ;p
22:20	joshuahickman	Hold on a sec, I have to retreat to my code-lab
22:23	joshuahickman	yeah, okay
22:23	joshuahickman	,(macroexpand (-> 2 #"" quote))
22:23	clojurebot	(#"" 2)
22:23	joshuahickman	Deliberately contrived example
22:23	joshuahickman	Which is to say, we should probably figure out how to either clean up the docs
22:24	joshuahickman	Or add in this feature to the next version of clojure
22:25	joshuahickman	Because it seems #() is the odd one out here, but not in a way that is documented, predictable, or advantageous
22:25	dnolen	joshuahickman: it's probably too minor a point to draw much interest. your one of the few I've seen talk about it much.
22:25	joshuahickman	Of course, I imagine this is likely the most inane silly detail
22:25	joshuahickman	yeah lol
22:26	tufflax	'() acts the same way
22:27	tufflax	,(macroexpand '(-> 1 '(a)))
22:27	clojurebot	(quote 1 (a))
22:27	tufflax	but, maybe that is not documented the same
22:28	joshuahickman	Well, that's interesting behavior
22:28	joshuahickman	I mean, I'm not surprised by it
22:28	joshuahickman	But it never occurred to me
22:28	joshuahickman	That one makes sense, though -- you are producing a list
22:28	joshuahickman	And -> looks for lists
22:29	joshuahickman	It certainly isn't the list you would like
22:29	joshuahickman	But at least the macroexpansion doesn't get muddled, as odd as that opinion sounds
22:29	joshuahickman	I mean, the quote has to go somewhere
22:30	joshuahickman	Anyhow, I always imagined '() working like @var
22:30	joshuahickman	That is was contracted to be identical to the function call
22:30	joshuahickman	So that's a plus
22:31	tufflax	but it does work like @
22:31	tufflax	,(macroexpand '(-> 1 @(a)))
22:31	clojurebot	(clojure.core/deref 1 (a))
22:31	tufflax	:p
22:31	joshuahickman	That looks the same
22:31	joshuahickman	I'm confused
22:32	joshuahickman	I mean, it's just deref vs quote
22:32	tufflax	but @(a) looks a bit strange
22:33	tufflax	not something one often sees i suppose
22:33	joshuahickman	But to the lisp reader, it doesn't matter if it is a list or a var, in terms of function or macro application
22:34	joshuahickman	I mean, the deliberately contrived examples might be confusing :)
22:34	dnolen	all which is this too illustrate that -> is syntax transformation applied after other forms have expanded. there be goodness and there be dragons :)
22:34	tufflax	yeah
22:34	joshuahickman	lol Indeed, sir
22:35	joshuahickman	I believe I'll use that to describe macros from now on
22:45	tufflax	by the way joshuahickman you said you were trying to use #(.split % "\\.") in the ->, but I guess you realize by now that (.split "\\.") would work
22:45	joshuahickman	yeah
22:46	joshuahickman	Actually, I think at the moment I just did a (let [splitByDot #(.split % "\\\.")] ...)
22:46	joshuahickman	Because I was tired
22:46	joshuahickman	But yeah, this wasn't a technical road-blocking issue
22:46	joshuahickman	It was quite surreal to hunt down that bug, though
22:46	tufflax	camelCase? eww
22:47	joshuahickman	Oh no! I got brainwashed by my java day job! :(
22:47	joshuahickman	I'll use dashes next time
22:47	joshuahickman	:)
22:47	tufflax	hehe
23:12	ibdknox	hey folks
23:12	ibdknox	if you're doing cljs stuff, you might find this useful: https://github.com/ibdknox/cljs-watch
23:23	dnolen	ibdknox: does it avoid the jvm restart overhead?
23:23	ibdknox	yessir
23:23	dnolen	ibdknox: sweet, are you going to submit this to ClojureScript?
23:24	ibdknox	I probably need to change it a little first
23:24	dnolen	ibdknox: do it!
23:24	ibdknox	but yes, it probably should be :)
23:24	dnolen	:)