#clojure – 2009-12-20

2009-12-20

00:05	scottj	Is there a function that inverts a tree? Not sure if that's the right name, but I want to convert (a (b 1)) to (b (a) 1)
00:28	alexyk	how do we do optional parameters?
00:29	scottj	&
00:29	_ato	(defn foo [x & [y z]] ...) y and z are optional (they'll be nil if not specified)
00:30	_ato	or (defn foo [x & options] ...) if you want any number of optional arguments (options will be a list of them)
01:09	tolstoy	So, I'm going to assume you can just 'export CLASSPATH="my-tons-o-jars" emacs' and be able to use Slime with code that depends on those jars. Right? ;)
01:10	efarrar	sounds reasonable tolstoy
01:10	efarrar	that's what i've experienced in the vim equivalent of slime
01:10	tolstoy	There doesn't happen to be a way to, say, (load "random-jar-file") right from the repl, is there?
01:11	efarrar	yes, but it doesn't always work for everything
01:11	tolstoy	I keep thinking about the ASDF stuff people have hacked up with Common Lisp.
01:11	tolstoy	Ah, okay.
01:11	tolstoy	I'm using Aquamacs, and it has a cool "server" mode, so I can start emacs from the command line pretty easily.
01:12	scottj	tolstoy: you can run M-x swank-clojure-project, tell it the dir of your project, and it will look in lib dirs and put all the jars on the classpath and start slime
01:12	scottj	,swank-clojure-project
01:12	clojurebot	java.lang.Exception: Unable to resolve symbol: swank-clojure-project in this context
01:12	tolstoy	Hm. I think I better take notes.
01:33	tolstoy	When you do a git fetch on, say, the 1.0.x branch. How do you diff what you just fetched? git diff HEAD 1.0.x? Something like that?
01:41	tolstoy	Which branch of clojure-contrib matches up with clojure 1.1-rc1?
01:53	ambient	hmm, i have a problem with clojure-project in emacs/swank-clojure where it doesn't find clojure.main, even when it's in my classpath. seems emacs overwrites that.
01:54	ambient	when I try and do M-x clojure-project on the project root
02:01	tolstoy	Hm. Swank doesn't seem to have used my CLASSPATH from when I started emacs.
02:02	tolstoy	At least if you go by (System/getProperty "java.class.path").
02:04	arbscht	tolstoy: you probably want to set swank-clojure-classpath
02:05	tolstoy	Where do I set that?
02:05	arbscht	in emacs
02:05	tolstoy	Oy.
02:06	tolstoy	Hm. That command doesn't exist. Or do you mean set something in .emacs?
02:09	tolstoy	ambient: When I run swank-clojure-project, I got some sort of hang on "polling" and nothing happens except a prompt for slime-abort-connection.
02:09	arbscht	tolstoy: try swank-clojure-extra-classpaths
02:10	tolstoy	arbscht: Are you talking M-x swank.... ? Cause there's nothing but the project thing.
02:11	arbscht	tolstoy: it's a variable in emacs -- do C-h v swank-clojure-extra-classpaths for info
02:12	tolstoy	So, you mean you have to edit your .emacs file whenever you switch projects and so on? Yikes.
02:13	arbscht	tolstoy: you could update its value at runtime too. depends what you want to do
02:14	ambient	tolstoy: yes, that's my problem too
02:15	tolstoy	Here I thought I was going to write some code, and now I have to figure out how to set a variable in emacs lisp. I never seem to get that sort of thing right.
02:15	tolstoy	Bitch bitch moan. I know it'll pay off in the end.
02:18	ssideris	writing code > setting up coding environment
02:18	ssideris	much much more preferable
02:20	tolstoy	Do I just put a string in there?
02:22	arbscht	tolstoy: a list of strings
02:22	tolstoy	So, I do the C-h v swank-clojure-classpath, and I see a (swank-clojure-classpath) in the flip-down. Do I just replace that with a stirng? Do I type in (setq swank-clojure-classpath '("patha", "pathb"))? I see no docs anywhere.
02:23	tolstoy	(setq swank-clojure-extra-classpaths (list "/class/path/1" .... ))
02:24	ambient	http://www.thibault.org/adder/ clojure on python, :P
02:29	talios	clojure on python is just wrong :P
02:29	talios	clojure on jython is where its at :)
02:30	ambient	just another layer of abstraction...
02:30	talios	Much like my polyglot maven/clojure work.
02:30	_ato	nice
02:30	_ato	that's something I
02:30	_ato	ve much thought about
02:30	_ato	a compiler to python/ruby/perl bytecode
02:30	_ato	for scripting etc
02:30	talios	abstractions on abstractions, abstracting the abstraction with yet more abstractions
02:32	ambient	it's cool how clojure is much more portable, lisp designed to sit on oop platform
02:42	tolstoy	Ah, man. I thought I'd just start-up swank-clojure as part of my app and then hook to it with emacs, but you can't even build it without maven, it seems. I so don't want to download Maven.
02:42	tolstoy	Maybe netbeans is the way to go for interactive dev.
02:44	_ato	tolstoy: http://clojars.org/repo/swank-clojure/swank-clojure/1.1.0-SNAPSHOT/swank-clojure-1.1.0-20091121.091400-2.jar
02:44	_ato	and it's built with leiningen not maven
02:45	tolstoy	Ah. I saw pom.xml and had to fight off the nitemares from a few years ago.... well, it wasn't that bad, I guess.
02:47	_ato	yeah, I understand. I've worked with it a while and I still find Maven frightening.
02:48	tolstoy	Yeah, it's like, "Cool! A neat little project!" Then, three hours of macports + downloading massive repos later, I get my simple little lib to play with.
02:49	_ato	yep... and no matter how many pom files I write, I still have to look up the syntax for even the most basic things. Same for the mvn command-line
02:50	tolstoy	I know people hate including jar files in your source tree, but, sheesh. It's sooooo much simpler. ;)
02:52	tolstoy	Okay. I've been complaining. Really, I worked all this out with CL a few years ago, and loved it. It's the damn CLASSPATH thing that gets me after a while.
02:52	tolstoy	BUT, I just started swank in a shell repl, and connected via emacs, and I LOVE IT!
02:52	_ato	:)
02:53	tolstoy	I can make a nice little shell script to get me started without having to mess with .emacs. Joy! ;)
02:55	talios	_ato - I'm working on maven polyglot support for clojure. no XML in site.
02:57	_ato	talios: yeah, I've been following. It's definitely an improvement, but XML is just the tip of the iceberg when it comes to Maven's horror. I integrated Maven into Clojars (for the repository deployment), using the Maven API directly and boy was that complex. The amount of hoops that Plexus (the auto-injector frameworky thing) makes you jump through to do anything is insane
02:58	tolstoy	How do you cleanly shutdown a swank server?
02:59	_ato	tolstoy: (System/exit 0) maybe?
02:59	_ato	I just Ctrl-C it normally :-P
02:59	tolstoy	Heh. swank.swank doesn't export a stop-server. ;)
02:59	_ato	there's a M-x slime-quit-lisp or something
02:59	talios	_ato: thankfully plexus is on the way out with maven 3 - guice baby guice :)
02:59	_ato	which I think just sends System/exit
03:00	johnmn3	g'day
03:00	tolstoy	M-x slime-repl-sayoonara does it, too.
03:01	_ato	talios: ah. I haven't looked at Guice, just Spring and now Plexus. So far I've got a rather negative opinion of dependency injection frameworks in general, but maybe it's just the ones (or the uses of them) I've been exposed to
03:02	johnmn3	I'm trying to build a simple swing repl. I'd like to somehow bind out and err to a JTextArea and in to a JTextField, but neither have a .getInputStream or something similar. How would you guys accomplish this?
03:06	_ato	you'd probably want to capture input/output for java code called from Clojure as well, so I'd probably use (System/setIn) with a PipedInputStream
03:06	_ato	and similar for output
03:07	_ato	you can override in for Clojure code just by doing (binding [in something] ...)
03:07	_ato	also see:
03:07	johnmn3	I was thinking of using a buffer and having another thread constantly flushing any content to the JTextArea, but I'd like to find a simpler solution... one where simply pressing enter (like at the regular repl) puts the code into to in, gets evaled, and automatically goes from out to the JTextArea
03:07	_ato	,(doc with-out-str)
03:07	clojurebot	"([& body]); Evaluates exprs in a context in which out is bound to a fresh StringWriter. Returns the string created by any nested printing calls."
03:08	johnmn3	ah
03:09	johnmn3	So I need to somehow wrap the JTextArea in a StringWriter and then bind that to out
03:11	johnmn3	_ato: the part where you said, "for the java code called from clojure," that would be covered by rebinding in and out right?
03:11	_ato	I don't think so
03:11	_ato	,(doc in)
03:11	clojurebot	"; A java.io.Reader object representing standard input for read operations. Defaults to System/in, wrapped in a LineNumberingPushbackReader"
03:11	_ato	cause java code would be using System/in and System/out directly
03:12	_ato	,System/out
03:12	clojurebot	#<PrintStream java.io.PrintStream@161daed>
03:12	_ato	,(.println System/out "hello")
03:12	clojurebot	nil
03:12	johnmn3	by java code, you mind like (.toUpperCase "hi")?
03:12	_ato	oh that's fine.. it's just if the java code has a print in it
03:13	_ato	if you don't care about threads/asynchronous output then just something like this might do the trick: (->> (.getText input-text-area) (read-str) (eval) (with-out-str) (.append output-text-area))
03:13	_ato	or whatever the appropriate swing calls are (I haven't used swing in years)
03:14	johnmn3	sounds about right... but what is with-out-str doing right here?
03:14	_ato	it's rebinding out for you
03:14	_ato	and turning the results into a string
03:15	_ato	,(with-out-str (println "hello world"))
03:15	clojurebot	"hello world\n"
03:15	johnmn3	ok, so we get a string and eval it.. then we take that string and make it the destination of the results, coming from out, then append it?
03:17	johnmn3	, (let [a "hi"] (with-out-str (println (let [a "123"]) a))))
03:17	clojurebot	"nil hi\n"
03:17	_ato	yeah, so we get a string, read it into clojure data structures with (read-string), then eval it like: (with-out-str (eval form)) so with-out-str returns a string of our output which we then add to the output text area
03:18	_ato	(reverse (with-out-str (println "hello")))
03:18	_ato	,(reverse (with-out-str (println "hello")))
03:18	clojurebot	(\newline \o \l \l \e \h)
03:18	johnmn3	whereas
03:18	johnmn3	,(reverse (println "hello"))
03:18	clojurebot	()
03:18	clojurebot	hello
03:18	_ato	right
03:19	talios	mm, for some reason the repl isn't printing stacktraces, is that an option I can turn on
03:19	talios	?
03:19	_ato	talios: hmm.. it should normally popup a new slime buffer thing with the stack trace
03:20	talios	bah - who uses slime ;p
03:20	_ato	oh you mean the repl directly?
03:20	_ato	that's weird then
03:20	talios	apparantly its a new feature to limit useless stacktraces ;:)
03:20	_ato	could try: (.printStackTrace *e)
03:20	talios	just did
03:21	_ato	hmm dunno then. I don't use a direct repl very often
03:21	talios	nah thats ok - as long as I know that its clojure supressing them by default, I'm ok with that
03:22	talios	sadly the trace didn't actually help thou
03:22	johnmn3	,(with-out-str (println (witherr?)))
03:22	clojurebot	java.lang.Exception: Unable to resolve symbol: witherr? in this context
03:22	johnmn3	,(println (witherr?))
03:22	clojurebot	java.lang.Exception: Unable to resolve symbol: witherr? in this context
03:22	talios	annoyingly - my macro throws a ClassCastException, but if I run its steps manually - its fine
03:22	_ato	johnmn3: yeah, you'll have to catch exceptions and do whatever you want to do with their stack trace
03:23	johnmn3	I'd like to do what the repl does, and just append them into the JTextArea
03:24	johnmn3	(doc with-err-string)
03:24	clojurebot	excusez-moi
03:24	johnmn3	,(doc with-err-string)
03:24	clojurebot	I don't understand.
03:24	_ato	~def with-out-str
03:32	johnmn3	works good
03:39	talios	'lo headius
03:39	headius	oh hai
03:41	johnmn3	does anyone know of an buffer kind of object I can get to automatically call (.append myJTextArea ), which I can use to .getOutputStream, for the purposes of binding err and out to?
03:42	johnmn3	with the new protocols, I wonder if I could extend some existing java queue or stream to do that.
03:46	vegai	are there any mechanisms for making a high availibility solution a la Erlang? With supervisors t al
03:47	tolstoy	vegai: I don't think so. Not built in.
03:47	talios	johnmn3: you could do that now with (proxy) and create out own OutputStream that appends to a JTextArea
03:49	johnmn3	hmm.. How do I explore the interface of OutputStream? does (show OutputStream) show me the methods I need to over-ride?
03:50	johnmn3	show shows it has three .write signatures
03:50	johnmn3	[12] write : void (byte[])
03:50	johnmn3	[13] write : void (byte[],int,int)
03:50	johnmn3	[14] write : void (int)
03:51	johnmn3	PrintWriter has a write : void (String)
03:52	johnmn3	can any class be extended like that?
03:53	talios	(proxy) just implements an Interface, it's not extending anything
03:54	johnmn3	I mean, are OutputStream or PrintWriter interfaces? Aren't they concrete classes (or whatever)? Do I need to find their interface counterparts?
03:58	talios	Mmm your right, they're classes. For some reason I was thinking they were interfaces.
03:58	talios	In that case I don't think (proxy) will help.
03:58	johnmn3	is there a command to message clojurebot with code, and he'll post it to lisppaste?
04:00	johnmn3	yea, something like a IPrinterWriter
04:03	_ato	johnmn3:
04:03	_ato	http://java.sun.com/j2se/1.5.0/docs/api/java/io/PrintWriter.html
04:04	_ato	wrapping a PipedOutputStream in a PrintWriter would be an alternative to using proxy
04:05	_ato	http://java.sun.com/j2se/1.5.0/docs/api/java/io/PipedOutputStream.html
04:10	talios	bah, that w00t was premature
04:12	johnmn3	ah'kkhaa
04:12	johnmn3	PrintWriter out = new PrintWriter(new TextAreaWriter(myTextArea));
04:14	johnmn3	ah, he's actually defining TextAreaWriter in the example.. I'll see if I can use proxy to create a TextAreaWriter
04:46	johnmn3	I'm trying to subclass Writer but I'm getting a ctor exception on String, with the relevant code as:
04:46	johnmn3	(write [cbuf off len]
04:46	johnmn3	(.append text-area (String. cbuf off len)))
04:47	johnmn3	Do I need to type hint here or something?
05:16	LauJensen	johnmn3: Best way to answer that question is (set! warn-on-reflection true) and compile the code
05:16	johnmn3	LauJensen: ok, will try that.
06:21	LauJensen	Blogged about the Arc challenge: http://www.bestinclass.dk/index.php/2009/12/beating-the-arc-challenge-in-clojure/
07:03	ambient	LauJensen: just by rapid reading, that really doesn't look like a solution to a challenge, but a trivial problem :)
07:05	_ato	LauJensen: it says in the "challenge" description: the value entered in the input field must not be passed in the url
07:05	LauJensen	really?
07:06	_ato	yep.. in the blockquoted bit
07:06	LauJensen	aah
07:06	LauJensen	Thanks :)
07:15	_ato	that "challenge" just seems to be saying hey arc ships with a continuation/closure based web framework in the standard library. Which I guess is okay, but not really very interesting if you've seen one before
07:18	LauJensen	True
07:18	LauJensen	But I think Compojure is suffiently elegant to want to show it to people
07:18	LauJensen	And now I get to show of the session middle-ware as well :)
07:19	_ato	hehe :)
07:23	_ato	eek
07:23	_ato	I'm looking at the Haskell version: http://gist.github.com/260052
07:24	_ato	I guess I must already be forgetting most of the Haskell of learnt
07:24	LauJensen	Its pretty complex
07:24	LauJensen	Go is kinda nice
07:24	LauJensen	Ruby looked nice, until I saw the custom library the guy made in order to make it nice :)
07:27	_ato	the Go version cheats to look nice, it uses mutable global state, so it'll break if two people access it simultaneously ;-)
07:27	_ato	though I dunno maybe Go has a nice sessions library
07:29	_ato	the ruby one is strange, dunno why he's using html strings for that, I thought sinatra had helpers for that
07:29	_ato	oh right
07:29	_ato	he says it doesn't hmm.. maybe I'm just think of rails / haml
07:31	LauJensen	_ato: link to your Wide Finder blog post plz?
07:32	_ato	LauJensen: you mean this link? http://meshy.org/2009/12/13/widefinder-2-with-clojure.html
07:35	LauJensen	thats the one
07:36	LauJensen	I linked that to your name, article now updated with session middleware instead of URL trick
07:43	_ato	actually, yeah you're right. With the sessions, that is quite a nice demo of all the basic bits of Compojure
07:43	_ato	certainly beats a usual hello world example
07:47	LauJensen	Glad you like it
07:51	LauJensen	_ato: I wonder if I should adopt your disclaimer from the top of your WideFinder article "This code can be reproduced in Java, which can be reproduced in C++, which can be reproduced in C, which can be reproduced in ASM, which can be reproduced in a Hex-Editor: Source code here" :)
07:54	_ato	hehe, the turing-completeness disclaimer. :-)
07:56	_ato	Yeah, I mainly added that cause I knew I'd get a swarm of comments saying... but you can do the same thing in language X. Which is beside the point.
07:57	arbscht	I believe the official designation was "Clojurian", not "Clojurist"
07:57	LauJensen	arbscht: correct
07:57	LauJensen	_ato: Did you succeed?
07:58	_ato	LauJensen: succeed at preventing the swarm of comments? seems so. :-)
07:58	LauJensen	I've tried to avoid certain types on comments in every post I've done - the only thing which works for sure is moderation :) When you speaking of a n-level language, I'd say anything you can do in N, you can also do in N-1. But nothing everything makes sense doing in N-1, so the important this is: Can you do it in N ? ... cryptic - but makes sense?
07:58	Luyt	Why is there need for vectors in Clojure? Can't lists do what vectors do?
07:59	LauJensen	Luyt: They cant have the same performance characteristics
07:59	_ato	Luyt: vectors allow fast indexed lookup. lists are slower for indexed lookup as they have to be traversed
07:59	Luyt	I see.
07:59	LauJensen	Ah thats a shame alex, too slow :)
07:59	hiredman	Luyt: you are asked if linked lists can offer constant time indexed access?
07:59	hiredman	asking
08:00	Luyt	I am reading the book and just wondered why there were both vectors and lists, but now that's clear to me.
08:00	Luyt	I thought maybe the one was immutable and the other not, like you have in Python (tuples vs. lists)
08:01	_ato	yeah, they're both immutable in Clojure
08:02	arbscht	there are also useful differences in semantics and syntax
08:02	arbscht	,(conj [1 2 3] 4)
08:02	clojurebot	[1 2 3 4]
08:02	arbscht	,(conj '(1 2 3) 4)
08:02	clojurebot	(4 1 2 3)
08:02	Luyt	,(into [1 2 3] 4)
08:02	clojurebot	java.lang.IllegalArgumentException: Don't know how to create ISeq from: java.lang.Integer
08:03	Luyt	,(into [1 2 3] [4])
08:03	clojurebot	[1 2 3 4]
08:03	Luyt	,(into '(1 2 3) '(4))
08:03	clojurebot	(4 1 2 3)
08:03	_ato	lists have the advantage that you can stick them on the front of other seqs, like lazy sequences or vectors, and adding them to the front of such objcets is really fast
08:04	_ato	where with a vector you'd have to convert the whole seq to a vector
08:04	hiredman	generally you don't into a list
08:04	hiredman	you just call seq
08:05	Luyt	That was my next question: why is there an 'into' if you already have 'conj' ?
08:05	hiredman	(which is not the same, but close enough for most cases)
08:05	_ato	,(into [1 2 3] [4 5 6])
08:05	clojurebot	[1 2 3 4 5 6]
08:05	LauJensen	,(reduce conj '() [1 2 3 4])
08:05	clojurebot	(4 3 2 1)
08:05	_ato	into is for conjing multiple things at once
08:05	hiredman	why have multiple instructions when a processor only needs one?
08:08	hiredman	I imagine rhickey found himself writing (reduce conj x y) so he packaged it up into (har) clojure.core
08:09	LauJensen	hehe
08:10	_ato	yeah, since it's such a common thing to do, it's worth naming even just for readability. "into" gives you a much better idea of the intent than "reduce conj" which requires more thinking about
08:11	_ato	and of course later on it turned out to be handy since, into can add transients
08:12	Luyt	Ah, I see, (conj [1 2] [3 4]) vs. (reduce conj [1 2] [3 4]) and (into [1 2] [3 4])
08:14	hiredman	,(conj [1 2] [3 4])
08:14	clojurebot	[1 2 [3 4]]
08:14	hiredman	very different
08:14	Luyt	Yes, (reduce conj [1 2] [3 4]) and (into [1 2] [3 4]) both return [1 2 3 4]
08:16	Luyt	Well, with that mystery solved I get another cup of coffee ;-)
08:16	LauJensen	Btw, for the rest of your bloggers who have had some difficulty getting good source highlighting for your Clojure-code. I made a little macro that works with htmlize, so to get code on my blog I mark the region and hit M-x blog, and its in my clipboard ready to be pasted in html :)
08:20	_ato	LauJensen: cool. htmlize is very handy. I'm currently using markdown with pygments for the highlighting, which looks like this: http://meshy.org/~ato/tmp/2009-12-13-widefinder-2-with-clojure.markdown.txt
08:21	LauJensen	Nothing is highlighted?
08:21	LauJensen	I think CGrand is also using some modified version of Pygments
08:22	_ato	I mean that's the source code
08:22	_ato	the highlighted output is in my blog post http://meshy.org/2009/12/13/widefinder-2-with-clojure.html
08:22	LauJensen	aah, gotcha
08:22	LauJensen	_ato: How did you set it up ?
08:23	_ato	LauJensen: using Jekyll: http://wiki.github.com/mojombo/jekyll
08:24	LauJensen	Ok - Maybe Htmlize is good enough after all :)
08:24	_ato	oh yeah, htmlize is fine, I use that quite a lot too. I just hate hand-writing long HTML pages
08:25	LauJensen	Yea, which htmlize saves me from - the only problem is if I need to edit, I usually just re-paste the whole thing
08:26	_ato	yeah, that's what I was finding too.
08:29	LauJensen	This was one of my first posts and I've received several emails (as late as earlier this week) asking me about the setup, how did I get it to look like that, which OS etc, http://www.bestinclass.dk/index.php/2009/09/layout-emacs-etc/
08:31	LauJensen	_ato: Sounds like you wrote this http://arclanguage.org/item?id=1521
08:34	_ato	hehe, nope. I like the BASIC version though. It really shows how complicated a "basic" app is these days compared to what it used to be. So much stuff (HTML, sessions, urls) you have to worry about that you didn't used to
08:34	_ato	on the other hand it's much easier to get images and different font sizes and such up in a webapp than it would be in basic. ;-)
08:37	LauJensen	So generally, would you say that you have a tendency to over-think things? :)
08:41	_ato	totally. simplicity is hard, and it just seems to keep getting harder the more technologies that are invented.
08:49	chouser	Hi, I'd like to discuss something that just hasn't received enough attention in quite a while.
08:49	chouser	parenthesis!
08:50	_ato	:O
08:50	liebke	haha, I've got this great idea for reducing the number of parentheses in Clojure!!! ;-)
08:50	_ato	the taboo word!
08:50	the-kenny	liebke: No! We need more of them.
08:51	liebke	:)
08:51	chouser	obviously parenthesis are ignorable and "disappear" over time
08:51	chouser	obviously parenthesis are the core and essence of a lisp
08:53	liebke	I do think people's perceived problem with parentheses is actually caused by deep nesting of function calls. I think more liberal use of 'let' is a solution to their problem, not reducing the number of parens
08:54	rhickey	There are several problems with parens, they need to be separated in order to talk about them
08:54	rhickey	first and foremost if the familiarity issue
08:55	rhickey	is the
08:55	rhickey	code as data is different from code using syntax
08:55	rhickey	so, first reactions are "I can't read that"
08:56	rhickey	an incorrect extension is "that is unreadable"
08:56	rhickey	just like someone who knows only Japanese might find English unreadable, but would be wrong to declare it generally so
08:56	Chousuke	depends on who's writing it :)
08:57	LauJensen	(.replaceAll rhickey "\n" ",")
08:58	LauJensen	I can't believe I'm not getting more love on HackerNewz, between me and Go I'm the only one who solved the problem
09:03	aldebrn	LauJensen, I just read your post on 1d automata and J, I wish more people withstood their impulse to badmouth something they find on the internet that they don't understand and don't like :P
09:03	_ato	mmm. Probably the functional thing is probably the larger stumbling block for people with an solely-imperative background. Trying to read Clojure without understanding functional programming is a pretty hard task. You're likely to come off thinking it's just gibberish and then not realising that's why it structurally looks so different blame the parens
09:05	_ato	I remember when I first encountered functional programming (Haskell) it took some time to wrap my head around. It felt like Haskell was totally unreadable at first.
09:06	LauJensen	aldebrn: Who badmouthed?
09:07	aldebrn	LauJensen, I meant, your comment ' I was planning to let him know, that only the writer of such hideous looking code could read it, but then I tripped over his blog...' You rock, I wish more people stopped to learn more about things like you did instead of just commenting negatively and forgetting :)
09:08	LauJensen	aaah, thanks - yea I'm glad I did, J is a good helper and truely a REPL language
09:09	aldebrn	I'm paranoid about my own ignorance but it took me a while to learn that others were less so, and I should assign internet comments very little weight. So many people have prejudices against Lisps, or anything-not-C#, etc..
09:10	aldebrn	J looks really cool, and it maps into Clojure well
09:10	LauJensen	True.
09:11	LauJensen	And yea, I hope to hook J into Clojure, calling the j.dll directly from a j macro, but I haven't got the prototype running yet
09:11	LauJensen	One thing you noticed quickly about J, is that its blazingly fast
09:12	LauJensen	s/you/I
09:15	aldebrn	j.dll faster than Clojure? Would it be worthwhile to have a Clojure-to-J compiler for speed?
09:17	chouser	I do think most lisps have a weakness around parens in that they can mean so many different things when used in code.
09:17	chouser	this is not a new statement from me. :-)
09:18	rhickey	chouser: exactly - it ends up that 'everything is a list' is not in fact the simplest
09:18	rhickey	due to this overloading
09:18	rhickey	that incidental complexity thing again
09:19	chouser	humans find visual hints to be very useful. {} meaning code blocks or hashes (usually formatted quite differently) is nice, to differentiate from (foo) as grouping and foo() as calling
09:20	rhickey	chouser: right, but taken farther that's the argument for syntax
09:20	chouser	foo(bar, baz) { bing(); bang(); } conveys some vauge but useful meaning even without knowing the meaning of the words.
09:20	chouser	rhickey: yes
09:20	chouser	(foo ((bar) (baz)) ((bing) (bang))) conveys almost no meaning at all.
09:21	chouser	(foo [bar baz] (bing) (bang)) is an interesting middle ground.
09:21	rhickey	so, why not syntax?
09:22	LauJensen	aldebrn: No, that would be a bad way to go. But for some things, mathematical expressions etc, a J interface would be nice, because at those things its much faster than Clojure I think
09:22	hiredman	chouser: it conveys no meaning because you are using nonsense words
09:23	chouser	homoiconicity buys simpler macros, simpler compiler, simpler debates about new feature syntax.
09:23	patrkris	is it correct to say that the STM in Clojure is dynamic?
09:24	chouser	hiredman: this is how code looks to people unfamilier with the vocabulary.
09:24	hiredman	chouser: algo syntax is just as uncomprehendable to people why haven't written code before
09:25	hiredman	lisp has syntax, it is expressed in words (symbols) rather than brackets and what not
09:27	Chousuke	I think vectors an maps give clojure enough syntax elements so that you can avoid overloading parentheses.
09:27	rhickey	chouser: those are downstream benefits. More syntax means more syntax rules, and thus more to understand., so more complexity up front. This might be amortized over a lifetime of use of a single language and thus might be a net gain. Once you learn more languages, there is less amortization and the per-language up front costs seem higher.
09:27	Chousuke	without having to have a "full" syntax like most languages.
09:28	hiredman	(defn f [x] x) vs. defn f (x) x end
09:28	hiredman	what's the difference? where is the syntax?
09:29	chouser	I don't think Clojure syntax would be harder to understand for first-time programmers than other languages. But relatively few people in that position are entering these discussions.
09:29	Chousuke	well, in the lisp case, the syntax is the macro mini language. ie. how it interprets the code elements
09:29	rhickey	hiredman: there is a huge difference. the structure, parens, always delimit, whereas you have to know end/; etc delimit
09:29	Chousuke	but the generic "structural" syntax is uniform
09:30	rhickey	and what matches with end
09:30	hiredman	rhickey: so not only does lisp have syntax but is has a more regular syntax
09:30	chouser	On the other hand, C, C++, Java, JavaScript, lua, etc. have similar enough syntax that once you've learned one or two, the work necessary to understand a lisp is higher than to understand another from the "C-like" category.
09:31	rhickey	hiredman: it has syntax for a very few data structures, at that point, you brain can organize code. AScribing it meaning goes to the words, but that's true in langs with syntax too. In langs with syntax, elaborate rules must be used to discern the structure before other things come into play. We've just internalized many of those elaborate rules
09:32	hiredman	actually I just finished watching some presentation of norvigs where he gives his reason for more or less jumping to python from lisp
09:32	hiredman	students reading the ai book couldn't seem to figure out how to map from the pseudo code in the book to lisp, but the pseudo code was almost an exact map to python
09:33	rhickey	a key question is, how much different a language can one learn if they are unwilling to have different syntax? Lisps want code-as-data for macros, Haskell wants juxtaposition as application (as big a leap from C-derivees) for its functional style
09:33	rhickey	does setting up an arbitrary limit on difference-from-what-I-know determine a hard limit for what you can know?
09:34	chouser	bbl
09:35	hiredman	I wonder what could be achieved if all the effort into lisp without parens went into, you know, doing something cool with lisp
09:35	rhickey	hiredman: but what about Norvig's point?
09:35	rhickey	seems somewhat valid
09:35	hiredman	rhickey: "you can't fight reality"
09:36	hiredman	the talk was actually about scientific computing with python and this just an antidote in the intro
09:36	fliebel	How can I dynamically add a jar to the classpath? add-classpath is deprecated, which most of the time means there is a better way.
09:36	Chousuke	well, the pseudocode was probably significantly more pythonlike in structure, so it was easier to associate with python.
09:37	hiredman	not having read the book (and not knowing common lisp) I cannot comment
09:38	Chousuke	but in doing so, the studetds may have relied too much on the "physical" structure of the code, rather than the logical structure.
09:38	hiredman	fliebel: I'd appreciate it if you could give http://gist.github.com/255766 a try
09:39	hiredman	if you run it as a clojure script it will create a cl.jar file and print out usage instructions
09:41	fliebel	hiredman: huh? I don't want to create a jar, I want a Java library accessible at the repl.
09:43	hiredman	fliebel: the clojure file generates a classloader that is then used to replace the system classloader
09:43	hiredman	the replacement classloader has a an "add" method
09:44	fliebel	ah...
09:46	hiredman	gah, typo, should be getSystemClassLoader
09:49	liebke	hiredman: I'd like to give your class loader a try. Can you give a usage example of adding a class/jar within a running repl? I'm not quite getting it from the usage message at the end of the gist.
09:51	hiredman	(.add (ClassLoader/getSystemClassLoader) (URL. "file:///some.jar"))
09:51	hiredman	(.add (ClassLoader/getSystemClassLoader) MyMagicalClassLoader)
09:54	liebke	hiredman: okay, so the URL points to a jar, I see. I really don't understand Java ClassLoaders, so the second example isn't clear, but the first one makes sense now. Thanks.
09:55	hiredman	the second example means you can make your own classloader that does magical things (bytecode on the fly?) and add that to be searched for classes
09:55	aldebrn	hiredman, rhickey, I'm a refugee from Python (too inflexible for very complicated things). My view is, if people think Python is more useful and easier than Lisp, fine, but I think they're wrong and I'm putting my money where my mouth is by working in and on Clojure
09:56	hiredman	:P
09:56	hiredman	~python
09:56	clojurebot	python is ugly
09:56	liebke	hiredman: cool, I'll leave the development of magical class loaders to you though :-)
09:57	aldebrn	I think someone here was commenting earlier that they thought Ruby was elegant until they saw the backend code that allowed for that elegance. I don't know ruby but I think that's a good description for Python too, all the nice elegant things in the language are unmalleable
09:58	hiredman	liebke: I don't know much about classloaders myself, this is just sort of a rough cut of a solution for adding classes during developement
09:59	liebke	hiredman: yeah, I think it can be very useful
10:08	fliebel	Is there a place to get a nice overview of the workings of all those different include, use, require, etc...
10:09	fliebel	I try to do something simple like including a clj file from the repl living in the working directory.
10:10	arj_	I'm having trouble bending 'some' to find a struct with a specific field in my sequence, any hints?
10:11	hiredman	,(some :foo [{:bar 1} {:foo 1}])
10:11	clojurebot	1
10:11	hiredman	,((comp first filter) :foo [{:bar 1} {:foo 1}])
10:11	clojurebot	{:foo 1}
10:12	arj_	aha nice
10:13	arj_	so that last one will all stop after finding the element?
10:13	Chousuke	yeah.
10:14	arj_	cool :-)
10:14	arj_	thanks
10:14	fliebel	I'm on the repl running in a directory where a few clj files are laying around, how can I use these?
10:15	fliebel	import and friend only seem to work with cp and java stuff
10:16	_ato	fliebel: maybe (load "somefile.clj")
10:16	_ato	but best would be to just add "." to the classpath
10:17	fliebel	like this? -classpath /opt/local/share/java/clojure/lib/*:.
10:17	_ato	yup
10:18	hiredman	fliebel: there is always load-file
10:18	fliebel	hiredman: I think that is easier than fiddling with cp…
10:19	fliebel	is there a :load thing for the ns macro?
10:19	hiredman	nope
10:20	hiredman	I highly recomend you get your classpath worked out and use the ns macro's :use and :require over relying on load-file
10:22	fliebel	hiredman: but after adding . to the cp I still can't get it to work… I got to get a clear image how Clojure works together with java.
10:23	hiredman	well, while "just add . to your classpath" is good advice, it doesn't take in to account the possibility that you don't have your namespaces/directory tree laid out well
10:24	hiredman	namespaces?
10:24	clojurebot	namespaces are (more or less, Chouser) java packages. they look like foo.bar; and corresponde to a directory foo/ containg a file bar.clj in your classpath. the namespace declaration in bar.clj would like like (ns foo.bar). Do not try to use single segment namespaces. a single segment namespace is a namespace without a period in it
10:25	lisppaste8	johnmn3 pasted "JTextArea out err" at http://paste.lisp.org/display/92391
10:25	fliebel	hiredman: that'll be the problem. I'm trying to run a file with a strange ns in the current dir, so I think that's why It's not working
10:25	johnmn3	can someone check that out? I can't figure out what the correct way to set the proxy up for Writer is.
10:26	johnmn3	I've found lots of guides online for socket-repls, but not swing repls
10:26	hiredman	johnmn3: you are missing implementations for write that take less then three args
10:26	hiredman	and that is not how you hint a character array
10:27	hiredman	and that is not how you hint ints
10:29	johnmn3	ah.. but the javadoc on writer states that you only override the three parameter write, I think. But I tried writing aritys from 1 to 4 parameters.. though I never had all 4 write methods written in the proxy.
10:30	hiredman	johnmn3: proxy overides by name, so if you provide an implementation for .write, it needs to handle all possible aritys for methods named write
10:31	hiredman	I would just toss out the hints
10:31	johnmn3	so do I do a method for each? (write [buf] ... (write [buf myint] ... etc. ?
10:31	johnmn3	yea, I probably don't need them.
10:32	hiredman	or you can (write ([buf] ...) ([buf int] ...) ...)
10:33	johnmn3	ah, rite
10:33	hiredman	if I recall the single arg .write can take a buffer or an int
10:33	johnmn3	damn, there's 5 write methods :/
10:33	hiredman	so you will need to check that
10:34	johnmn3	int, string, or char[]
10:34	fliebel	Most of the time noobs like me actally do something wrong when they find a bug, but this seems quite strange to me: (line-seq (BufferedReader (FileReader. "/some/file")))
10:34	fliebel	java.lang.Exception: Expecting var, but BufferedReader is mapped to class java.io.BufferedReader
10:34	johnmn3	missing the dot?
10:34	hiredman	http://gist.github.com/107140
10:35	johnmn3	BufferedReader_._
10:36	fliebel	johnmn3: hmm, you're right ashamed
10:36	johnmn3	fliebel: I just did that a few minutes ago
10:37	johnmn3	hiredman: so you've had that hanging around.. this is what I've been working on all day.
10:37	hiredman	johnmn3: no guarantee that it works or whatever, I haven't touched it in a while, and if I recall it was finicky
10:38	johnmn3	ok
10:40	hiredman	wow, yeah, I recall tearing my hair out over treating jta's as a reader and a writer
10:41	johnmn3	I like that add-ctrl-enter-listener. I was going to add that too.
10:41	johnmn3	so you used an OutputStream instead of a PrintWriter
10:42	hiredman	yeah, I went as low as possible, because there were fewer operations to support
10:43	hiredman	and then it gets wrapped in an OutputStreamWriter and then a PrintWriter
10:45	johnmn3	I'm probably just going to use your code as a base.
10:45	hiredman	by all means
10:48	johnmn3	npe.. I'll hack on it and try to find it.
10:52	hiredman	huh
10:52	hiredman	yeah, it runs, but I could some kind of npe
10:53	hiredman	oh, right, you have to select what you want to run, then hit C-<RET>
10:53	johnmn3	ah, you have to highlight the code to ctrl-enter. with nothing highlited...
10:53	johnmn3	right
10:55	johnmn3	I was thinking of doing some kind of tokenizer, to eval whatever expression is within the matching parens to the left of the caret.
10:55	johnmn3	like (+ (+ 1 2) 3)\| <ctrl+enter> evals to 6
10:56	cemerick	I didn't check my clojure list inbox for a couple days, and then return to find a bunch of pissing-into-the-wind about eliminating parens.
10:56	hiredman	right, not wanting to do that, I went for the easy fix
10:58	benji	I'm a newby and don't understand why the highlighted line in http://pastebin.com/d24a97957 doesn't seem to have any effect.
10:59	johnmn3	what are the right terms I want to be using to find examples of doing that? clojure tokenizer ?
10:59	the-kenny	benji: map is lazy
10:59	the-kenny	benji: Wrap the map-thing in a (doall (map ...))
11:00	hiredman	johnmn3: I doubt you will find examples
11:00	benji	!!
11:00	benji	gotcha
11:00	hiredman	but I think you just need to count parens
11:00	hiredman	(basically)
11:00	the-kenny	benji: map applies the function when needed. If you do (take 3 (map ...)), it only creates the first 3 elements
11:01	hiredman	the-kenny: take is lazy
11:01	benji	thanks the-kenny; got it working
11:01	the-kenny	hiredman: Oh.. bad example ;)
11:01	hiredman	:P
11:03	tolstoy	Is there a way to get the (println ...) output of another thread to show up in the emacs / slime buffer?
11:03	the-kenny	tolstoy: It shows up in the inferior lisp buffer
11:04	tolstoy	the-kenny: Yeah, I'm seeing that. Is that pretty much all we got?
11:04	the-kenny	hm.. I'm not sure if it's possible
11:07	aking	tolstoy: (add-hook 'slime-connected-hook 'slime-redirect-inferior-output)
11:08	tolstoy	aking: Cool, thanks!
11:10	tolstoy	Examining hiredman's hack to get setName working on PircBot....
11:36	hiredman	tolstoy: it's in contrib now, towards the end of java-utils
11:53	the-kenny	Looks like the docstring for c.c.math is broken - It ends with: "[...] the floor of the square root and the ".
11:55	the-kenny	http://richhickey.github.com/clojure-contrib/math-api.html
13:31	johnmn3	which do you think would be preferable for a text editor that can evaluate code when the caret is next to the expression... in front of the expression or behind the expression?
13:32	johnmn3	I was thinking behind, because you could write the expression, then immediately evaluate it, without having to move the caret back to the front of the expression.
13:32	johnmn3	or is there a better idiom all together.
13:32	johnmn3	?
13:33	the-kenny	johnmn3: I think all three are possible in emacs.
13:33	JonSmith	i think emacs does 'evaluate last expression'
13:35	johnmn3	well, if we had (+ 2 3 )<caret>(- 2 3) and we hit the evaluate keys, which would get evaled?
13:36	johnmn3	I suppose shift+ctrl+enter could be the opposite of ctrl+enter
13:39	johnmn3	if evaluating to the right of the caret in the following expr: (let [a 3] <caret>(+ 1 a)) would emacs error with a being undefined?
13:40	cark	emacs evals top-level or after caret on same line or toplevel before caret on same line
13:41	cark	at least that's how i picture it
13:41	cark	so you're stuck at doing it all =D
13:42	johnmn3	also, if using paredit, if getting the caret to the right of the closing parens is a pain, people will rather eval from the opening parens
13:44	scottj	Is there something in contrib that will invert a tree (is there a better name for this?), like turn (a (b _ 1) 2) to (b (a _ 2) 1) ?
13:45	johnmn3	not sure what you mean by "or toplevel before the caret on the same line".. do you mean, wherever a caret is on a given line, it will scope from the outermost expression on that line and all subexpressions on the following lines that belong to that outer scope (which started on the line the caret was on)?
13:46	johnmn3	scottj: does the _ have to stay in the inner expr?
13:47	scottj	johnmn3: yeah, but I'd be interested if there's a solution when it doesn't.
13:49	cark	johnmn3 : you should install emacs with clojure-mode and make some tests
13:49	cark	it does the right thing
13:50	johnmn3	scottj: I don't know of something that automatically inverts a tree like that in contrib.. but you might be able to do it easily. depends on how you want to deal with unbalanced trees, I think.
13:51	johnmn3	cark: yea, I should.
13:52	scottj	johnmn3: for the example I gave (3 elements in each list), can you give me a hint on how you'd solve it?
13:57	johnmn3	I'd split the list down the center. For cases where the list had an odd number of elements, I'd put the extra element on the right side I guess. I think it'd be more interesting with a list like this: (a (b (c d e) f g) (h I) (j k (l ( n (o p)))))
13:59	johnmn3	maybe tagging each element with a "nest-level" and then rebuild a list from left to right but flipping the nest-level for each element.
14:00	johnmn3	it looks like (o p) are the deepest level, at 5. So an inverted list might look more like (((((a) b) c d e (f ... etc.
14:02	scottj	cool, thanks for the ideas. One place this can be used is if you want to generate a bunch of unit conversion functions, but only define the relationship one way. For fahrenheit to celsius you'd write (/ (* (- % 32) 5) 9) then you could easily generate the inverse. I'm hoping to use this to define a few unit relationships and then generate a bunch of unit conversion functions that combine them.
14:03	johnmn3	hmm
14:04	scottj	(of course you also have to invert the operations)
14:04	johnmn3	that'd be cool.. I don't think my last example would be what you want then.
14:18	lisppaste8	johnmn3 pasted "get-expr" at http://paste.lisp.org/display/92397
14:19	johnmn3	theres my get-expr function... grabs expression from it's matching paren, starting from the paren on the right.
14:19	johnmn3	kinda ugly.. feel free to pretty it up.
14:21	johnmn3	also, it's not yet smart enough to detect ")(" or
14:25	johnmn3	It's a little naive.. will be hard to add that smartness to it without some kind of smarter parsing mechanism.. I thought I remember someone already wrote some kind of parsing library for clojure.
14:29	johnmn3	perhaps using a cond instead will allow for more flexibility and extension.
14:37	rads	if I'm adding something to a vector and I don't care about the order, does it matter if I use cons or conj?
14:38	devlinsf	rads: I think conj is more idiomatic
14:38	JonSmith	i thought cons returns a seq
14:39	JonSmith	yup
14:39	JonSmith	,(cons 1 [2 3 4 5])
14:39	devlinsf	,(class (cons :a [:b]))
14:39	JonSmith	hmm
14:39	JonSmith	no clojurebot :-(
14:39	devlinsf	,(class (conj [:b] :a))
14:39	devlinsf	Ah!!!!
14:40	devlinsf	Well, I just ran mine at a REPL
14:40	JonSmith	api says so, if you trust it
14:40	devlinsf	a cons returns a clojure.lang.Cons object
14:40	devlinsf	conj returned a clojure.lang.PersistentVector
14:41	devlinsf	If you are expecting a vector back, you must use conj
15:37	tolstoy	Folks, how to you matchup clojure-contrib with any given branch of clojure? For instance, which clojure-contrib goes with clojure 1.1?
15:38	devlinsf	tolstoy: We're working on freezing a branch w/ 1.1
15:38	devlinsf	tolstoy: for now, use master
15:38	tolstoy	Okay.
15:39	tolstoy	Good enough for me. ;)
16:10	johnmn3	does anyone know how clojure's repl implements it's ability to not eval until a closing parens is matched to the opening one?
16:11	johnmn3	I'm reading the source for main/repl and I"m not seeing it.
16:16	chouser	johnmn3: do you mean how pressing <enter> early still doesn't cause it to eval?
16:16	johnmn3	right
16:17	johnmn3	I'd think it counts parens, but it knows not to count escaped parens from strings or characters
16:17	chouser	the 'read' function reads from a stream until it has read a whole form or eof
16:17	chouser	at the repl, the input stream blocks until you type something and press <enter>, so while it's blocked, so is 'read'
16:18	chouser	'eval' isn't called until after 'read' returns.
16:19	johnmn3	I want to implement the ability into a gui repl, where you can eval a form with a ctrl+enter..
16:20	johnmn3	so I'll need to feed-read a character stream from the caret of the JTextArea into read, and it'll know when to eval?
16:21	johnmn3	It'll just keep reading until EOF and spit out for extra characters like: java.lang.Exception: Unmatched delimiter: )
16:23	johnmn3	making get-expr to get a desired form, while accounting for all the escaped parens is proving difficult :)
16:25	chouser	yeah, I wouldn't try to parse it yourself. that's what 'read' is for.
16:27	chouser	What I did was feed 'read' a StringReader. If it threw an "EOF while reading" exception, I knew the input was incomplete. :-)
16:27	AWizzArd	Hi guys, what‘s new? :)
16:27	johnmn3	but read can't tell me when a given function ends in the middle of a lot of functions in a JTextArea, can it?
16:28	johnmn3	AWizzArd: not much
16:28	devlinsf	johnmn3: Use read-string
16:28	devlinsf	combine and actionlistener on a JTextField & read-string
16:29	johnmn3	devlinsf: what do you mean?
16:30	devlinsf	Well, JTextArea fires a ActionEvent when you press enter
16:30	devlinsf	So, I'd make my action listener list this
16:30	devlinsf	(read-string (. getText my-j-text-area))
16:31	johnmn3	yea, but I don't want to eval the whole document.. just the form next to the caret
16:31	devlinsf	OH
16:31	devlinsf	:(
16:32	devlinsf	I thought you were trying to use a command line input
16:33	johnmn3	I've got a function that counts parens (if open-paren (inc parens)) (if close-paren (dec parens), more or less, which works...
16:34	AWizzArd	does the Master branch on github now include everything from the NEW branch?
16:34	devlinsf	AWizzArd: for core?
16:34	johnmn3	but I need to account for all the cases in which parens are loose or escaped, where the reader doesn't normally count them.
16:34	AWizzArd	devlinsf: yes
16:34	devlinsf	AWizzArd: No. In fact, this is the point of releasing 1.1
16:35	johnmn3	and I don't even know what all the cases are.
16:35	devlinsf	AWizzArd: most of new is going to wait for 1.2
16:35	AWizzArd	I used NEW in the past weeks, since the first checkins of deftype, but now see this 1.1.x and Master and New and don't know which is for me.
16:35	devlinsf	AWizzArd: new has the deftype stuff. 1.1 explicitly does not
16:36	AWizzArd	So, is New still mostly a superset of 1.1.x and Master?
16:36	devlinsf	johnmn3: You could split the body by lines, and add them one at a time
16:36	devlinsf	AWizzArd: Yeah, new is a superset
16:37	AWizzArd	k, thx
16:37	johnmn3	devlinsf: what do you mean?
16:38	devlinsf	johnmn3: Assume the body of your document is split by #"[\r\n]"
16:38	johnmn3	separate toplevel functions by whitespace?
16:39	devlinsf	johnmn3: Start taking lines one at a time
16:39	devlinsf	johnmn3: Yeah
16:39	devlinsf	It's ugly, but it might work
16:39	johnmn3	yea.. the programmer must adhere to that convention.
16:40	johnmn3	well, are there cases I'd need to account for other than ")" "(" /) and /( that' I'd need to drop from my counting?
16:41	devlinsf	Well, depends
16:41	devlinsf	That might cover 99.9% of stuff
16:41	johnmn3	if there are few enough cases, I'll just hack out a gnarly cond until it works.
16:41	devlinsf	Are you willing to frustrate your user at .1%?
16:42	johnmn3	do defmacros allow for a an unbalance paren?
16:42	devlinsf	Sometimes .1% wrong is acceptable
16:42	johnmn3	no, I wouldn't want it to be broken for even a small percent.
16:42	devlinsf	Okay. Spend some extra time test then
16:43	devlinsf	Sounds like you've got a good direction to go now
16:43	johnmn3	yea.
16:44	johnmn3	are there any quoting things, ~ @ # ` ' or any others that clojure makes floating (un-paired) parens accepted?
16:45	devlinsf	Not that I'm aware of
16:46	johnmn3	testing the get-expr fn against all the fns in core would probably do the trick, eh?
16:46	devlinsf	The reader treats ~ and company as a character
16:46	devlinsf	Look at clojure.lang.LispReader.java for more info
16:47	johnmn3	ok
17:03	AWizzArd	Why is long producing an overflow without an exception, while incing a long might throw one?
17:03	AWizzArd	,(long 9223372036854775808)
17:04	AWizzArd	,(inc (long 9223372036854775807))
17:05	qed	,(unchecked-inc (long 9223372036854775807))
17:10	AWizzArd	also interesting behaviour: starting from 64x the same digit, it produces funny outputs, for example -1 for (long 9999999999999999999999999999999999999999999999999999999999999999). But I can add some 9's and it will always stay -1.
17:10	AWizzArd	When I add in some different digits then the output will change
17:11	Licenser	AWizzArd: I'd guess it is because it's an cast which thinks 'the user will know what they do when forcing this to be a long)
17:14	AWizzArd	I just would not expect from testing (long 62digit '5') that (long 64digit '5') or (long 69*digit '5') will always produce 4099276460824344803.
17:17	hiredman	ping?
17:17	johnmn3	pong
17:18	johnmn3	hey, thanks for the help yall. later
17:19	hiredman	AWizzArd: 9999999999999999999999999999999999999999999999999999999999999999 is a bigint with out the cast to long
17:19	hiredman	so you get a different combination of ops from c.l.Numbers
17:19	hiredman	grrr
17:21	AWizzArd	hiredman: ah, interesting, thanks for the info.
17:22	hiredman	huh
17:22	hiredman	people don't waste anytime, clojurebot isn't even back in channel yet and it is already getting privmsg'ed stuff
17:23	hiredman	ping?
17:23	hiredman	clojurebot: hello?
17:23	clojurebot	BUENOS DING DONG DIDDLY DIOS, fRaUline hiredman
17:23	hiredman	clojurebot: ping
17:23	clojurebot	PONG!
17:25	hiredman	, (type 9999999999999999999999999999999999999999999999999999999999999999)
17:25	clojurebot	java.lang.ExceptionInInitializerError
17:25	hiredman	:(
17:25	hiredman	,(type 9999999999999999999999999999999999999999999999999999999999999999)
17:25	clojurebot	java.lang.ExceptionInInitializerError
17:25	hiredman	huh, worked at my repl
17:26	qed	works here too
17:26	hiredman	works at clojurebot's repl
17:26	hiredman	,(type 9999999999999999999999999999999999999999999999999999)
17:26	clojurebot	java.lang.ExceptionInInitializerError
17:26	hiredman	,(type 9999999999999999999999999999999999)
17:26	clojurebot	java.lang.ExceptionInInitializerError
17:26	hiredman	,(type 9)
17:26	clojurebot	java.lang.Integer
17:26	qed	,(type (bigint 9999999999999999999999999999999999999999999999999999999999999999))
17:26	clojurebot	java.lang.ExceptionInInitializerError
17:26	hiredman	interesting
17:26	hiredman	~clojurebot
17:26	clojurebot	clojurebot has a lot of features
18:15	AWizzArd	Is there a hook for implementing my own printing behaviour (in the repl) for my deftypes?
18:18	liebke	AWizzArd: you should be able to use print-method for that
18:19	AWizzArd	ok, this is what i thought, but i was not sure if there is already another way for doing this
18:20	liebke	I haven't heard of a new way, but here's an example of the print-method for Matrices in Incanter, https://gist.github.com/96a1b26706acd55ea0e2
18:51	AWizzArd	I remember I read something about a keyword-let or with-keywords thing. Is it already decided if this will go into Clojure?
19:01	devlinsf	Hey, anybody here run OS X.6 ?
19:02	the-kenny	devlinsf: Me
19:02	the-kenny	10.6.2
19:02	devlinsf	the-kenny: The bundled JVM works?
19:02	the-kenny	devlinsf: Yes
19:03	the-kenny	But I think you can change the default jvm in some settings program, wait
19:03	the-kenny	Java SE 6 64 Bt is my default jvm.
19:04	devlinsf	Okay. I run 10.5 now, I'm probably gonna make the upgrade over the Holidays
19:05	devlinsf	the-kenny: Thanks for answering my questions
19:05	boyd	/Applications/Utilities/Java Preferences but on snow leopard I think you only get Java SE 6
19:05	the-kenny	The update is trivial. I had not a single problem
19:05	the-kenny	boyd: Yes, SE6 is the only available option, but there's one with 32 and one with 64 bit
19:06	boyd	Agreed
19:06	devlinsf	good to know
19:07	the-kenny	compilation of programs is a bit tricky because the gcc wants to create code for ppc, i386 and x86_64 by default.
19:41	Luyt	devlinsf: What I did: I just replaced the harddisk in my macmini and installed snowleopard on it. If it wouldn't work well, I could always swap my old HD in.
19:41	Luyt	devlinsf: I think installation on an external HD works as well, to try things out.
19:42	devlinsf	Luyt: I've got a macbook pro, so I can't do that :(
19:42	Luyt	Well, an external HD then.
19:42	devlinsf	Oh, external??
19:42	devlinsf	Hmmm...
19:42	Luyt	Yes, you can perform an install of snowleopard on an external HD, and even boot from it too ;-)
19:45	Luyt	But I just decided to put an Intel X25 SSD into my macmini, put Snowleopard on it, then transfered over my important files from the old harddisk (which I hooked up with a SATA to USB kit)
19:52	the-kenny	Yeah, I've done it a step more: I cloned my internal hd onto an external and upgraded sl on the external to check everything out
19:52	the-kenny	as everything was fine, I upgraded my internal hd after that :)
20:12	tolstoy	Before I go and write something, is there a function that tells me if any member in a given list A is somewhere in list B?
20:12	_ato	,(some #{4} [1 2 3 3 4 5 6 6])
20:12	clojurebot	4
20:13	_ato	,(some #{42} [1 2 3 3 4 5 6 6])
20:13	clojurebot	nil
20:13	tolstoy	,(some '(a b) '(1 2 3 4 a c))
20:13	clojurebot	java.lang.ClassCastException: clojure.lang.PersistentList cannot be cast to clojure.lang.IFn
20:13	_ato	,(some #{'a 'b} '(1 2 3 4 a c))
20:13	clojurebot	a
20:14	_ato	,(doc some)
20:14	clojurebot	"([pred coll]); Returns the first logical true value of (pred x) for any x in coll, else nil. One common idiom is to use a set as pred, for example this will return true if :fred is in the sequence, otherwise nil: (some #{:fred} coll)"
20:14	tolstoy	Is there somewhere that groups related core functions rather than just presents them in a big list?
20:15	_ato	http://clojure.org/sequences
20:15	tolstoy	Ah, right!
20:15	_ato	also: http://clojure.org/cheatsheet
20:15	tolstoy	I need to start book marking those subject pages. Thanks.
21:09	ztellman	is there any way to pull javadoc strings off of a method at runtime?
21:10	chouser	I don't think there's any javadoc stored in the runtime
21:10	chouser	but clojure.contrib.repl-utils has a 'javadoc' fn that will launch a browser pointing at whatever class you mane.
21:11	ztellman	hmm, I was hoping it was saved with the reflection information
21:11	ztellman	oh well
21:20	interferon	flatten seems to completely flatten a list, is there a way to simply flatten the highest level?
21:23	chouser	,(apply concat [[1 2 3] [4 5] [6 7 [8 9]]])
21:23	clojurebot	(1 2 3 4 5 6 7 [8 9])
21:24	interferon	makes sense
21:24	interferon	thanks
21:31	tolstoy	error: java.lang.IllegalStateException: repeat already refers to: #'clojure.core/repeat in namespace
21:31	tolstoy	Hm. str-utils2 not playing nice with core?
21:34	_ato	tolstoy: you're supposed to import str-utils2 with an alias. eg (:require [clojure.contrib.str-utils2 :as str])
21:34	_ato	and then to str/join or whatever
21:34	tolstoy	Yeah, I did that, but it's not working. Maybe I've slimed on repl too many.
21:36	KirinDave	Does anyone know whats the mystic invocation to get leiningen to pull down the 1.1.0-RC1?
21:36	tolstoy	Something wrong with (ns (:use [clojure.contrib.str-utils2 :str str]))?
21:36	tolstoy	Oops. I meant :as.
21:43	tolstoy	Nope. Aliasing str-utils2 doesn't seem to work.
21:53	chouser	tolstoy: add :only [] to your :use clause.
21:53	dublindan	I'm trying to redirect where the repl gets its input from, im trying to do something like this: (binding [in my-in] (clojure.main/repl))
21:53	dublindan	but i cant seem to figure out how to implement my-in
21:53	tolstoy	chouser: Thanks. I've relented and gone that route. Works! ;)
21:54	dublindan	I just want to be able to return a string, but proxying clojure.lang.LineNumberingPushbackReader makes me have to create Readers and such, which seems like a lot of work to simply return a string
21:56	chouser	dublindan: you want repl to read from a string?
21:56	hiredman	,(read-string "foo")
21:56	clojurebot	foo
21:56	hiredman	?
21:57	dublindan	chouser: I want the repl to read its input from an external source, so i was trying to implement readLine and such to return the string read from elsewhere
21:58	chouser	dublindan: socket? file? string?
21:58	hiredman	http://gist.github.com/107140
21:58	dublindan	chouser: a java.util.concurrent.LinkedBlockingQueue
21:59	hiredman	read doesn't need neading a LNPBR
21:59	dublindan	hiredman: thanks, that looks like it might do what I want
22:01	alexyk	some cross-language fun: tried to see what a workflow would look like in Haskell. Now Haskell has no built-in maps. There's a module for it, and calls look like: M.insert x y m. So here scripting languages with built-in hashes really make it look better.
22:02	KirinDave	Man, I love the way constantly reads.
22:02	KirinDave	Seriously good name for a function.
22:03	alexyk	,(doc constantly)
22:03	clojurebot	"([x]); Returns a function that takes any number of arguments and returns x."
22:03	KirinDave	In hiredman's code:" :need-prompt (constantly false)"
22:03	KirinDave	good stuff
22:04	alexyk	,(constantly [1 2 {:a 1}])
22:04	clojurebot	#<core$constantly__4953$fn__4955 clojure.core$constantly__4953$fn__4955@1c7510d>
22:04	alexyk	,(constantly 3 [1 2 {:a 1}])
22:04	clojurebot	java.lang.IllegalArgumentException: Wrong number of args passed to: core$constantly
22:04	alexyk	ah
22:04	KirinDave	(constantly true) and (constantly false) are popular.
22:05	alexyk	,(let [fc (constantly [1 2 {:a 1}])] (constantly 5))
22:05	clojurebot	#<core$constantly__4953$fn__4955 clojure.core$constantly__4953$fn__4955@13638d4>
22:05	alexyk	,(let [fc (constantly [1 2 {:a 1}])] (fc 5))
22:05	clojurebot	[1 2 {:a 1}]
22:05	alexyk	there
22:06	alexyk	from the stupid dog tricks dept. :)
22:06	alexyk	is (iterate inc 0) the shortest way to create infinite integer stream?
22:06	alexyk	Haskell has [1..] or something.
22:10	dublindan	hiredman: thanks, that worked perfectly!
22:17	AWizzArd	Is there a foo for which (foo :my.namespace/kw) ==> ::kw ?
22:24	JonSmith	alexyk: a lot of the haskell material really helps to read to understand clojure stuff
22:25	tomoj	AWizzArd: isn't ::kw just a shortcut for :my.namespace/kw ?
22:26	alexyk	JonSmith: funny thing, I used OCaml for a while and looked at Haskell several times, but the lack of built-in maps makes them look paler for data mining. Hashtbl.insert or Map.insert ... is not flowing. But FP is pretty much the same.
22:26	AWizzArd	tomoj: there is a reader macro which transforms ::kw into :my.namespace/kw. I look for a function which goes the other way around.
22:26	alexyk	strangely sexps look nicer now. You don't have to ponder parenthesizing.
22:26	alexyk	you just do it.
22:27	alexyk	(just (do it))
22:27	JonSmith	yup
22:27	JonSmith	i've never gotten the argument against sexps
22:28	JonSmith	although
22:28	JonSmith	(if (you (do (it (alot)))))
22:28	tomoj	AWizzArd: I guess..
22:28	tomoj	,(keyword (str ":" (name :my.namespace/foo)))
22:28	clojurebot	::foo
22:28	tomoj	?
22:29	alexyk	there should be a magic Closing Bracket. (you (do (it (a (lot} ; } closes all
22:30	JonSmith	i forget what that is called
22:30	JonSmith	one of the lisps had that
22:30	alexyk	the opening parens are usually clear. The closing chunk is an orgy of closing.
22:30	JonSmith	hyperparen or something
22:30	alexyk	btw a friend of mine can't understand why clojure needed to pollute lispiness with ugly []s
22:30	JonSmith	although, its not like you are going through trying to figure out how they match up :-)
22:30	alexyk	he's like, [wtf?]
22:30	alexyk	JonSmith: I do! I blink them all
22:31	AWizzArd	tomoj: yes, this works. I just thought there may be something else already in it.
22:32	alexyk	are []s for vectors, and thence fun params? why couldn't we do without them?
22:32	JonSmith	i think of clojure as a datastruture programming language rather than list processesing
22:32	alexyk	why are they needed in let, for, doseq?
22:32	alexyk	JonSmith: exactly
22:33	alexyk	I dig []s for vectors, but why is fun params, doseq, let, not clear
22:33	JonSmith	i think its just for differentiation of binding forms
22:33	alexyk	ah
22:34	JonSmith	like in CL you have (let ((var 1) (var 2)) (+ 1 2))
22:34	AWizzArd	Gives your eyes more substance to perceive.
22:34	JonSmith	and that lets you differentiate the different variables with an extra set of parens
22:34	JonSmith	clojure just uses different brackets
22:34	alexyk	AWizzArd: or more irregularity to stumble on
22:35	AWizzArd	if you think so, then don't use an editor with paren highlightning
22:35	alexyk	AWizzArd: my editor is rlwrap
22:36	AWizzArd	you can have small irregularity by writing programs via 0 and 1 :-)
22:36	JonSmith	it is a bit of a pain for certain macros (there is an extra step for binding forms), but otherwise I'm kind of neutral on it
22:37	AWizzArd	I did CL 6 years before I discovered Clojure. I prefer the Clojure style, using []s.
22:38	AWizzArd	alexyk: you can write your own let which will behave like CLs if you wish.
22:38	tomoj	alexyk: why insist on rlwrap?
22:38	AWizzArd	n8
22:39	alexyk	well I enjoy Clojure, that's just what my friend asks :)
22:39	alexyk	tomoj: simple for remote server
22:39	tomoj	ah
22:39	tomoj	actually..
22:39	tomoj	how?
22:39	tomoj	sounds more complicated to me
22:40	alexyk	tomoj: works for now, my lein has rlwrap java ... in it. technomancy added it for me. :)
22:41	tomoj	oh, but you're not editing files on the remote server?
22:41	alexyk	rlwrap stores history locally, is searcheable, beats jline hands down.
22:41	alexyk	tomoj: my TextMate has a command to send a selection to the term where the repl is.
22:42	tomoj	yeah, but I think I've heard you here more than once complaining about the different ways that clojure is hard to write :)
22:42	tolstoy	alexyk: Oh, cool. Do you just start up a swank server and TextMate sends to it?
22:42	alexyk	but most often I do one-ling-liners in repl and paste them back locally if they're worth it. I don't use swank at all.
22:42	tolstoy	Ah.
22:42	alexyk	TextMate sends either the current line, or selection if present, to the tab of iTerm called "Clojure".
22:42	tomoj	meanwhile I have paredit in my repl, so.. not very sympathetic :P
22:43	alexyk	tomoj: that's the part of clojure-mode for emacs?
22:43	tomoj	no paredit is separate
22:43	alexyk	is there a single .el I can drop into .emacs and be uber-clojure-emacs-geek?
22:44	tomoj	I don't think so
22:44	alexyk	or a couple... is there a fixed agreed upon clojure-mode?
22:44	JonSmith	that's a good idea though
22:44	JonSmith	there is clojure-mode and paredit
22:44	JonSmith	slime is nice too
22:44	tomoj	and swank-clojure
22:44	JonSmith	yeah
22:44	alexyk	is slime orthogonal to swank-clojure?
22:44	JonSmith	you know, i don't think i even use slime with clojure
22:45	liebke	I wrote about setting up emacs, slime, swank, and paredit today: http://incanter-blog.org/2009/12/20/getting-started/
22:45	tomoj	I think package.el can install them all
22:45	JonSmith	yup
22:45	tomoj	liebke: cool
22:46	alexyk	liebke: you da man again!
22:47	liebke	:)
22:47	tomoj	I think there are some tweaks to paredit needed
22:47	alexyk	liebke: you bowed before the magesty of maven, too! :)
22:48	liebke	ah, I've resigned myself to it for Incanter, but I wouldn't recommend it to smaller projects. I just need Leiningen to work correctly on the Mac again
22:49	alexyk	liebke: I think mvn is a safe bet, especially for cross-platform stuff with Java and (performant) Scala.
22:50	alexyk	but nothing prevents pom.xml and project.clj from coexisting
22:50	liebke	true. and when talios has got polyglot support for clojure-based config files, I think it will be fine.
22:55	alexyk	liebke: I'm surprised how well sexps work for data-mining. You can have a long one-liner which does a clearly defined job, and is well-bounded. OCaml or Haskell would have multi-liners, harder for repls and copy-pasting.
22:56	alexyk	and built-in maps are the killer
22:56	liebke	I agree, sexps are great on a repl, much better than any other syntax I'm familiar with
22:57	alexyk	I'm pondering things like joins of maps on keys for graphing. That's a generalization of my typical EDAs. Combine one x with various y's.
22:57	alexyk	When data is in Mongo, that joining can be done selectively quering the database.
22:58	liebke	very cool, i'm hoping you'll write about your set up some time
23:00	alexyk	liebke: yep, after the submission deadline for a paper is done with...
23:00	liebke	great