#clojure – 2008-11-23

2008-11-23

00:59	albino	Does the plus sign in the docs for aset represent varargs?
01:01	hiredman	(doc aset)
01:01	clojurebot	Sets the value at the index/indices. Works on Java arrays of reference types. Returns val.
01:03	hiredman	it must
01:09	gnuvince_	albino: it's like with regexes; ? is when there's none or one, * when there's none or many and + when there's at least one.
01:12	albino	user=> (aset a 0 1 10)
01:12	albino	java.lang.IllegalArgumentException: Argument is not an array (NO_SOURCE_FILE:0)
01:12	albino	I can't get it to work with more than one index
01:15	Chouser	I think the multiple indexes is for multi-dimentional arrays.
01:15	Chouser	(aset a 1 2 10) is like a[1][2] = 10
01:20	albino	ahhh
01:20	albino	we need that in the docs
01:22	albino	I thought it was a[1] = 10; a[2] = 10;
01:23	Chouser	yeah, that's a reasonable guess. And it does appear the actual behavior isn't even hinted at in the docs.
01:24	Chouser	that I can find, anyway.
01:26	notallama	how can i tell how a sorted set will be sorted?
01:26	notallama	is there any way to give it a comparator?
02:45	albino	Do I need to import things from clojure.core? I figured it would all be imported by default.
02:50	danlei	From (doc ns) If :refer-clojure is not used, a default (refer 'clojure) is used.
04:06	Lau_of_DK	Top of the morning gents! =)
04:06	kotarak	Hi Lau!
04:20	hiredman	clojurebot: Lau_of_DK is <reply>Top of the morning #who!
04:20	clojurebot	You don't have to tell me twice.
04:20	hiredman	clojurebot: Lau_of_DK?
04:20	clojurebot	Top of the morning hiredman!
04:21	Lau_of_DK	:)
04:35	tWip	webjure now supports regex patterns on the path... and binding groups
04:40	Lau_of_DK	webjure != compojure ?
04:40	Lau_of_DK	@ tWip
04:40	tWip	no, they are two different projects
04:40	tWip	I don't know about compojure
04:40	Lau_of_DK	You mean, "Yes, they are two different projects"
04:41	Lau_of_DK	What makes webjure special ?
04:41	tWip	I think webjure came first
04:41	Lau_of_DK	oh :)
04:43	tWip	compojure seems to have more of a community
04:44	Lau_of_DK	Why the fork then. Wouldnt you get more done by merging the two projects?
04:44	tWip	I don't think they forked
04:51	tWip	and no, I think exploring different ways to make a web framework for Clojure is useful
04:51	tWip	maybe one de-facto will emerge in time, but it's good to have choice
04:53	Lau_of_DK	tWip: alright
06:19	Lau_of_DK	So - Anyone doing anything interesting in Clojure?
06:20	kotarak	Not in, but for actually. Working on VimClojure improvement. Hmmm.. So interesting maybe depends on the point of view. ;)
06:20	Lau_of_DK	Yes - Im not really into the revival of discarded editors though, but others might find it interesting, so thanks for sharing =)
06:21	Lau_of_DK	Did you check out Chousers online Repl, kota ?
06:21	kotarak	The Browser Repl?
06:21	Lau_of_DK	yea
06:22	kotarak	I had a look, but cannot claim, that I understood everything. I'm not that deep in javascript and browser stuff.
06:22	Lau_of_DK	He wrote part of it in C, I think you can find the whole thing in contrib
06:23	blackdog_away	i wonder why chouser doesn't use an applet with clojure
06:24	Lau_of_DK	Hmm...
06:24	Lau_of_DK	Thats actually a very good question.
06:24	Lau_of_DK	blackdog, did you ever find a way to wrap JQuery nicely in Clojure?
06:25	blackdog_away	i suppose his method is likely to woork 100% with no requierment for jdk installation
06:25	blackdog_away	yes, clojurescript works
06:25	blackdog_away	i did a one line test, but it can be done
06:25	Lau_of_DK	Chousers own words were that it was not ready for production yet
06:26	blackdog_away	i think its a technology in search of an application
06:27	Lau_of_DK	As it is, JQuery is so simple to write out in plain javascript, that I'd prefer to have the thing operational beore using it
06:27	Lau_of_DK	But maybe thats just me
06:27	blackdog_away	agreed, it needs the killer app
06:28	blackdog_away	as js is a tad entrenched to beat up on
06:29	Lau_of_DK	How do you mean blackdog_away ?
06:30	blackdog_away	well there are too many plus points with js for clojurescript to really be an option
06:30	blackdog_away	unless there was a killer app
06:30	blackdog_away	another negative is it needs compiled
06:33	Lau_of_DK	I agree with the first part. But I dont see how the compilation is any different from anything else that goes out of Clojure
06:33	Lau_of_DK	@ Big Black Dawg
06:33	blackdog_away	well, compared to js on the client it's a problem
06:33	Lau_of_DK	So you mean, that it takes away from the performance we would normally free from the server?
06:35	blackdog_	no, simply an extra compilation step is not so good for the client i think
06:36	blackdog_	if you're used to working with gwt etc or java web frameworks it's a no brainer,
06:36	blackdog_	but for your average web designer type, they don't want another step
06:37	blackdog_	well i suppose you can argue that flash etc all require extra steps too
06:37	blackdog_	i guess that's why i don't like any of them :)
06:38	Lau_of_DK	Weird attitude :)
06:38	Lau_of_DK	I mean, I agree that we should plan ahead with resources in mind. But this step that youre worrying about is not likely to cause any problems, anywhere?
06:38	Lau_of_DK	Or am I being short sighted now?
06:39	blackdog_	well, for example, i was using haxe a lot last year, and it's excellent, great for the web,
06:39	blackdog_	but really with the advances in js and great debugging
06:39	blackdog_	it's hard to beat straight js/dom
06:40	blackdog_	that's really all I'm sayin
06:40	blackdog_	the point of haxe being it's an extra compilation step too
06:40	blackdog_	and it just becomes old
06:40	Lau_of_DK	k
06:40	Lau_of_DK	You want the comet?
06:41	blackdog_	?
06:41	Lau_of_DK	Comet? You work with Comet now right?
06:41	blackdog_	i wrote a wrapper for the jetty comet chat server in clojure
06:42	Lau_of_DK	k
06:42	blackdog_	but that's all, i need to know more about
06:42	blackdog_	it
06:43	Lau_of_DK	btw, BlackDingDawg - Do you know how to set up a standard apache2 server to handle the static pages, and then have it proxy all dynamic pages to a jetty or something like that?
06:44	blackdog_	not really i use nginx these days to do exactly the same thing
06:45	blackdog_	but it won't take yo long to goog for mod_proxy
06:45	Lau_of_DK	Im sure it wont, but I have zero experience, so if you knew how, I'd prefer to hear it from you
06:47	blackdog_	can't remember of the top of my head
06:59	Fib	Is there any significant difference between ((fn a [seq] (foo seq)) seq) and (fn b [& args] (apply foo args))? Would there ever be a limit on the number of args to a function?
07:01	jaan	uuu. snowstorm. lights are blinking. i'll better go offline..
07:02	timothypratley	b is easier to call?
07:02	timothypratley	opps that doesn't answer your question /hides
07:05	Fib	hehe
07:11	Fib	It's true (apply b seq) and (b z y x) are very easy while (a `(~z ~y ~x)) is a bit uglier
07:11	Fib	But if you want to chain serveral operations on a sequence then calling apply each time would be awkward...
07:11	kotarak	I hope that his is a joke: (a (list x y z))
07:11	kotarak	s/his/this/
07:12	Fib	Ah I see
07:12	Fib	Sorry, I am a complete newbie :)
07:12	kotarak	no problem. I was scared by the quotation usage. :)
07:13	kotarak	Fib: it depends on what you want to do. eg. map gets a collection. (map transform-element some-seq)
07:14	kotarak	(apply map transform-element some-coll) seems odd.
07:15	Fib	Yeah, that's what I was thinking
07:15	kotarak	(it has an application though: (apply map transform-pair [first-coll second-coll])
07:15	Fib	I was defining a function "average" and wondering if that should take varargs or a sequence
07:17	kotarak	Probably a seq. Rationale: (defn average "Returns the average of the elements of coll." [coll] (/ (reduce + coll) (count coll)))
07:19	kotarak	Equally well not a seq: Rationale: + and friends also take variable numbers of arguments...
07:19	kotarak	Hmmm... Don't know. Personal preference maybe�
07:20	Fib	:)
07:20	Fib	I'm still trying to understand the (apply map transform-pair [col1 col2]) example you gave though
07:21	Fib	Is that any different from (map transform-pair [col1 col2])?
07:21	kotarak	(map (fn [x] (transform x)) xs) vs. (map (fn [x y] (transform x y)) xs ys)
07:21	mehrheit	Fib: it's the same as (map transform-pair coll1 coll2)
07:21	Fib	ah ok
07:22	kotarak	Fib: it was bad example from my side. Since map actually accepts multiple arguments.
07:23	timothypratley	Good question really, I'd be interested in when to use a vs b. At a guess I'd imagine b is good for cases where you generally only have a few arguments, whereas a is good when you want to use larger sequences eg (range 100)?
07:23	timothypratley	average is a tricky example
07:24	timothypratley	I would say it is more likely you want to use it for large sets
07:24	timothypratley	so a is more convenient
07:24	kotarak	timothypratley: I think it depends on whether you want to work in the collection as an argument or whether the collections the arguments.
07:25	kotarak	Geez, I'm confused today. Sorry. I don't even understand what I'm trying to say myself...
07:25	timothypratley	hahahaa, I agree I'm just trying to figure out how to tell the difference :)
07:25	kotarak	reduce expects a collection which it transforms into something else.
07:26	kotarak	+ adds two or more numbers.
07:27	kotarak	Ok. I'm confused. Sorry.
07:27	timothypratley	yes... one could quite easily define + as opperating on a collection of 1 or more elements
07:27	timothypratley	and vice versa
07:28	kotarak	I'm looking for a good example.
07:28	timothypratley	I think the rational would be that usually people use + with only 1 or two args
07:28	kotarak	Say struct: (struct foo :a :b :c) creates a new foo map with the given values.
07:28	kotarak	Now you get [:a :b :c] from somewhere else.
07:29	kotarak	Then you use apply: (apply struct foo the-vector)
07:30	kotarak	Providing the values always in a collections, doesn't make sense, because the number is well-defined.
07:31	kotarak	Something like that maybe? Would go along your argument about the "usual" call.
07:33	tWip	should an empty list be a seq?
07:33	tWip	(seq? ()) => false
07:33	timothypratley	Sounds reasonable :) Average is tricky because well you do want to take the average of 2 numbers sometimes... othertimes maybe you want to average a large set of data, its hard to say which is more likely... wouldn't it be great if both forms were supported??? but surely that is impossible (and confusing).
07:34	kotarak	tWip: I think the empty list is Collection not a Seq.
07:35	tWip	yes, but what is the reasoning behind that?
07:36	Chousuke	tWip: it's an empty list, so as a sequence, it's "nothing". I guess that's why it's not automatically a seq
07:36	Chousuke	you can do (seq ()) and get nil
07:36	kotarak	tWip: a collection is something specific, while a seq is an abstract view on a specific collection
07:38	tWip	easy to work around, I still feel it should be a seq
07:39	danlei	how to do this? (in a non-ugly way) have not looked at multimethods so far
07:39	danlei	(defn avg ([s] (/ (reduce + s) (count s))) ([x & args] (/ (+ x (reduce + args)) (inc (count args)))))
07:42	kotarak	(defn avg [x & args] (/ (reduce + x args) (inc (count args))))
07:42	kotarak	ups
07:42	kotarak	sorry. Forget it. Misread your function.
07:43	danlei	in cl, i'd specialize on list in the first case (first method of a generic function), a number in the second case. i guess, that could be done with multimethods. i'll have a look at them later.
07:44	Chousuke	tWip: you just need to remember (seq coll) whenever you work with sequences :)
07:46	Fib	Isn't it because () doesn't support (first) and (rest) and thus doesn't match the abstract interface of a sequence?
07:48	tWip	ok, I changed my usage to coll? and calling seq... it's no big deal, just seemed weird at first
07:53	timothypratley	danlei: that seems to work great :) thanks. why do you call it ugly?
07:54	danlei	because it is so ugly, that only a mother could love it =)
07:54	timothypratley	hahahah
07:54	danlei	but yes, it works
07:54	danlei	*chuckles
07:58	Lau_of_DK	danlei: I must say, you havent convinced me that a mother could actually love it :(
07:59	danlei	well, maybe a very benevolent one ;)
08:00	danlei	you know how to do it with multimethods? still hadn't the time to check them out
08:00	Lau_of_DK	oh youre right.. or maybe a blind one, who used to code a little Python way back when :)
08:00	danlei	=)
08:10	timothypratley	danlei: well if you think yours is ugly... wait till you get a load of this:
08:10	timothypratley	(defn avg [s & nots]
08:10	timothypratley	(if (seq? s)
08:10	timothypratley	(apply avg s)
08:10	timothypratley	(/ (reduce + s nots) (inc (count nots))))
08:10	timothypratley	then...
08:10	danlei	it's alive!
08:11	timothypratley	(defnaa avg [s] .....) => above
08:11	bottleneck	anyone know of a guide to a simple webserver
08:11	Lau_of_DK	bottleneck: To write one, or to use one?
08:11	bottleneck	write
08:11	MarkVolkmann	What is the function that expands a list so that each value can be used as a separated argument to a function?
08:12	bottleneck	jsut want to do a simple one to see hown they work
08:12	Lau_of_DK	bottleneck: I think I have a guide for a Jetty/clojure server in about 100 lines or so, want me to dig it up ?
08:12	bottleneck	yes please, would be awesome
08:12	tWip	added basic json support to webjure
08:12	blackdog_	bottleneck, http://robert.zubek.net/blog/2008/04/26/clojure-web-server/
08:13	Lau_of_DK	bottleneck: thats the one that blackdog_ posted
08:14	danlei	MarkVolkmann: you mean apply?
08:14	Lau_of_DK	tWip: I think somewhere along the way I got JQuery and Json mixed up. What does JSon specifically enable me to do ? I know its serilization, but when will I need it ?
08:14	blackdog_	your browser reads json natively
08:14	tWip	most likely when you call your servlets from javascript code using AJAX
08:14	blackdog_	it's a subset of javascript
08:15	blackdog_	jquery is a nice library that helps you select then appy actions to dom elements
08:15	tWip	and much much more
08:15	tWip	jquery has some very nice UI plugins
08:15	Lau_of_DK	JQuery is my weapon of choice, when I want to move formatting operations and such, away from the server and onto the client, as I see it
08:15	blackdog_	still a bit limited in the UI package
08:16	Lau_of_DK	Am I to take it, that JSon is the format in which I pass my data to JQuery ?
08:16	blackdog_	no official grid yet
08:16	blackdog_	yes
08:16	Lau_of_DK	k, thanks
08:16	blackdog_	there's a $.getJSON method
08:18	Lau_of_DK	It confused me a bit blackdog_ when you were explaining your servlet approach to me. You said "This way, I dont need Jetty", and then you sent me an example using Jetty =)
08:18	blackdog_	i don't need to, but i do, could be any server, jetty is very convenient
08:18	blackdog_	the point is the client is not tied to a jsp/asp or php
08:19	blackdog_	why tie yourself to a server framework when you can tempalte on the client?
08:20	Lau_of_DK	To get cool t-shirts from Microsoft?
08:21	bottleneck	Lau_of_DK: thanks!
08:24	Lau_of_DK	no probs
08:42	MarkVolkmann	Suppose foo is the list (1 2 3) and I want to pass the items in it as individual arguments to a function. What expands a list like that? (my-function (??? my-list))
08:43	rhickey	MarkVolkmann: (apply + foo)
08:43	danlei	(apply my-function my-list)
08:43	MarkVolkmann	Thanks!
08:44	danlei	wtf
08:44	danlei	why does cond return nil?
08:45	rhickey	danlei: tradition, a la one-branch if
08:45	danlei	hm
08:46	danlei	what should i use instead? nested ifs?
08:47	Chousuke	what kind of code?
08:47	rhickey	danlei: for what purpose? cond only returns nil if no condition matches
08:47	danlei	the cond kind of code
08:47	danlei	wait a sec
08:48	danlei	(cond [true 1]) -> nil
08:48	danlei	i'm used to cl: (cond (t 1)) 1
08:49	danlei	not a problem, just /very/ surprising to me
08:50	danlei	or do i miss something?
08:50	Chousuke	cond doesn't take a vector.
08:50	Chousuke	(cond true 1) -> 1
08:51	danlei	oh my
08:51	danlei	now, that's embarassing =)
08:51	danlei	thank you
08:56	MarkVolkmann	To get the metadata for a function, say str, I enter (meta #'str). What do the # and single-quote do in this context?
08:58	Chousuke	that returns var named by str
08:58	rhickey	MarkVolkmann: #' is a reader macro. When read, #'x reads as the form (var x)
09:00	MarkVolkmann	Thanks! I need to go read more about vars.
09:06	danlei	ok, now that i know about cond ... ;) how would i dispatch on type, i.e. if something is/are a number/numbers, or a collection?
09:06	danlei	i tried like this:
09:06	lisppaste8	danlei pasted "avg" at http://paste.lisp.org/display/70915
09:06	danlei	works. is that the way to do it?
09:07	danlei	(first multimethod so far)
09:08	danlei	... at least, it's not as ugly, as the other one ;)
09:10	fanda	hello!
09:10	fanda	question about fn?
09:10	Lau_of_DK	Hey fanda
09:10	Lau_of_DK	shoot
09:10	fanda	(def x 5) => #'user/x
09:10	fanda	(var x) => #'user/x
09:10	fanda	(fn? (var x)) => true
09:10	fanda	true or false?
09:11	duck1123	should be
09:11	fanda	why is var a function?
09:13	rhickey	fanda: why are all vars functions?
09:13	rhickey	var is a special form
09:14	rhickey	vars are functions because it is useful for them to be so - they all implement the IFn interface in terms of a call to their value, which must in turn be a fn
09:14	Lau_of_DK	Guys, simple question (I hope)
09:14	Lau_of_DK	(defmacro onClick [obj & body] `(. ~obj addMouseListener (proxy [MouseListener] [] (~'mouseClicked [evt#] ~@body))))
09:15	Lau_of_DK	Why does this not work in a JPanel which implements addMouseListener?
09:15	Lau_of_DK	s/in/on
09:15	fanda	thanks rhickey! that makes sense. just double checking tests for Clojure predicates
09:17	rhickey	fanda: Imagine you had some global fn foo, if you passed foo to (hang-onto-this foo), you would be passing the current value of foo. If you later fixed foo, hang-onto-this wouldn't see the change. If instead you passed (hang-onto-this #'foo) then it would. In either case it could 'call' what it was passed
09:18	rhickey	Lau_of_DK: I'm on a mission - no one should ask a macro question by posting only the source of the macro - please post an invocation and actual and/or expected expansions
09:19	rhickey	and please paste
09:19	Lau_of_DK	Alright Rich Norris, I'll get right on it
09:22	rhickey	Chuck Norris doesn't say please
09:22	Chouser	I was thinking the other day of a "macro help request" form with separate sections for each.
09:23	rhickey	Chouser: great idea!
09:23	duck1123	is there an easy way to add metadata to a file? It's looking like we might need a way to store things about files (ie. filename, author, license) as clojure data
09:23	Lau_of_DK	Chouser: does Rich actually sponsor you ? :)
09:23	rhickey	duck1123: files are not first-class constructs in Clojure, but namespace metadata has been requested
09:24	lisppaste8	Lau_of_DK pasted "mouseListener" at http://paste.lisp.org/display/70916
09:25	mmcgrana	Hey Rich, very sorry about the clj-doc license issue, I'm working on it right now.
09:25	rhickey	mmcgrana: np
09:25	duck1123	that was why I bring it up
09:26	rhickey	mmcgrana: I'm sorry I didn't get to look at it sooner - very neat
09:26	duck1123	what if clj-doc indexes non-clojure core code, it'd have a different license
09:27	mmcgrana	rhickey: thanks
09:27	mmcgrana	hopefully I'll have it set up on a proper server at a permanent URL for 1.0
09:28	mmcgrana	duck1123: perhaps if i do the license notice per-function, like under the source code.
09:29	rhickey	Lau_of_DK: please try macroexpand-1 on your macro before pasting
09:29	Lau_of_DK	rhickey: macroexpand-1 is basically what you see in the bottom of the paste
09:29	duck1123	mmcgrana: have you thought any about using iframes? As much as I hate them, they make it easy to see code and function list seperately
09:30	rhickey	i.e. paste real code you have tried, rather than having others try for the first time
09:30	lisppaste8	Lau_of_DK annotated #70916 with "macroexpand-1" at http://paste.lisp.org/display/70916#1
09:30	rhickey	user=> (macroexpand-1 '(onclick panel (javax.swing.JOptionPane/showMessageDialog nil "Clicked")))
09:30	rhickey	(onclick panel (javax.swing.JOptionPane/showMessageDialog nil "Clicked"))
09:31	Lau_of_DK	rhickey: Ive tried this code, and variations on it for quite some time
09:31	Lau_of_DK	Your error is just because C is lowercase in on_C_lick
09:31	Lau_of_DK	It was just meant as an example to understand what I was aiming for
09:32	mmcgrana	I was thinking something like this http://skitch.com/mmcgrana/hqgn/clj-doc-clojure-library-documentation.
09:33	mmcgrana	Any ideas on how to disambiguate the text: i.e. what software its referring to exactly, which files, etc.
09:33	phil	Hey all. How do I create a new var without interning it?
09:34	Chouser	(doc with-local-vars)
09:34	clojurebot	varbinding=> symbol init-expr Executes the exprs in a context in which the symbols are bound to vars with per-thread bindings to the init-exprs. The symbols refer to the var objects themselves, and must be accessed with var-get and var-set
09:34	phil	Great, cheers.
09:35	rhickey	Lau_of_DK: and I wasted my time trying to get it to work, it's simple courtesy to make a decent try yourself first and paste only code you have run
09:36	Lau_of_DK	rhickey: Im sorry about the typo, but like I said, I've tried this code several times in several variations.
09:37	rhickey	mmcgrana: looks fine. I think you could 'attach' the notice to the corresponding code by putting it in the same box
09:38	mmcgrana	ok good idea
09:38	rhickey	mmcgrana: but in this case, the notice applies to the doc as well
09:39	rhickey	mmcgrana: so what you have is fine
09:41	danlei	ok, another cl/clojure question: in cl, if a symbol is read, it gets interned in the package you're in. then it may e.g. be bound to a special (symbol-value slot). i have read that clojure differs here, and symbols don't get interned, but vars do, and that symbols are only names, or somehting. could someone just quickly name the main differences between symbols/vars in cl and clojure and the consequences?
09:42	phil	danlei: Symbols are interned in a namespace which is a mapping from those symbols to vars. Vars in turn are bound to other values.
09:42	danlei	so symbols /are/ interned, when they're read, like in cl?
09:42	danlei	but don't have a value-slot, but are ... "names"(?) for vars?
09:48	rhickey	phil: not quite, symbols are not interned in namespaces inherently
09:48	danlei	rhickey: does it boil down to "symbols are just names"?
09:48	rhickey	(identical? (symbol "foo") (symbol "foo"))
09:48	rhickey	false
09:49	rhickey	symbols are just names, but with faster equality than strings
09:49	danlei	ah, ok
09:50	rhickey	because symbols' names are interned strings
09:50	rhickey	but the symbols themselves aren't interned, so they can support metadata
09:51	rhickey	vars are much more like CL's symbols, but still not identical
09:52	danlei	if i do (resolve 'x), for example
09:52	rhickey	vars are (normally) interned in a namespace, are named by a symbol in that namespace, have root value bindings and can be thread-locally bound
09:52	danlei	i get a var back, if it's def'ed
09:53	rhickey	danlei: right, and that resolution happens at compile time, not read time - the reader reads symbols
09:54	danlei	rhickey: ok. i think it's clearer now
09:54	rhickey	but symbols can name other things, like classes, too
09:54	rhickey	user=> (resolve 'String)
09:54	rhickey	java.lang.String
09:55	danlei	ok
09:56	danlei	and i can't resolve that symbol, because resolve works on vars, and the argument to resolve would be the symbol which names it, right?
09:56	danlei	(which names the var)
10:02	danlei	ah, ok. i actually /can/ resolve it, since returns the var /or/ class.
10:09	mmcgrana	new docs w/ license notice are uploaded: http://clj-doc.s3.amazonaws.com/tmp/doc-1116/index.html
10:09	MarkVolkmann	I recently ran across function definitions like this. (defn- -foo ...) I understand that defines a non-public function. Is the fact that the name of the function starts with a dash a convention for private functions or a requirement?
10:10	kotarak	-foo is a method for the class defined by the namespace.
10:10	kotarak	defn- says it's private.
10:10	kotarak	as a clojure function, I mean.
10:11	MarkVolkmann	It looks like I don't have to start the number of the function with a dash though. It must be a convention to do so.
10:12	kotarak	?? "number of the function"?
10:15	Lau_of_DK	kotarak: I think he means "name of the function"
10:15	Lau_of_DK	We just have to hope Rich doesnt catch him makings typos like that, you know how he gets :)
10:16	kotarak	Oh. If I remember correctly, for the new AOT gen-class one has to start the method names with a dash. For private function this is not necessary.
10:17	rhickey	mmcgrana: sorry, I missed the lack of copyright notice - text should start with: Copyright (c) Rich Hickey. All rights reserved.
10:17	MarkVolkmann	Right, I meant name, not number.
10:18	mmcgrana	ok np
10:18	rhickey	MarkVolkmann: right -name is the name to which an AOT generated class method will be bound
10:19	MarkVolkmann	If I change the default namespace using (ns my-ns), is there an easier way to pop back to the previous default namespace than something like (ns user)?
10:20	Lau_of_DK	rhickey: Are you the one who updates ants.clj when something new happend to Clojure?
10:20	rhickey	MarkVolkmann: you should only use ns for namespace definition, use in-ns to change namespaces, and no, there isn't 'back' function for namespaces
10:20	rhickey	Lau_of_DK: yes
10:21	Lau_of_DK	rhickey: I didnt really understand the latest change where (send-off agent self) becomes (send-off agent #'self). Can you explain that for me?
10:22	MarkVolkmann	I tried defining a private function with a name that didn't start with a dash and it worked as expected. I couldn't use the function from another namespace. That's why it seems to me that starting the function name with a dash is just a convention.
10:22	kotarak	MarkVolkmann: a name with a dash has nothing to do with private functions.
10:22	rhickey	MarkVolkmann: name starting with dash is completely unrelated to defn- and private
10:23	kotarak	defn- defines a private function.
10:23	kotarak	defn -foo defines the method foo for some class
10:23	kotarak	(.foo x) translates to the function -foo
10:24	MarkVolkmann	Is (defn -foo) a way to add a method to an existing Java class?
10:24	MarkVolkmann	How does it know which class I want to add to?
10:25	kotarak	MarkVolkmann: no monkey patching here, you have to derive (ns my.fancy.Class (:gen-class :extends this.other.Class) (defn -methodToOverride ....))
10:25	rhickey	MarkVolkmann: With AOT compilation, each namespace becomes a class. You can declare with a :gen-class clause in ns the superclass and interfaces that class extends/implements
10:26	rhickey	then define the overidden or declared methods by defn-ing -methodName functions
10:26	mmcgrana	rhickey: like this? http://skitch.com/mmcgrana/hqe8/clj-doc-clojure-library-documentation
10:26	rhickey	as kotarak said, no monkeypatching
10:27	rhickey	mmcgrana: great, thanks
10:29	MarkVolkmann	It's tough to tell from the documentation why I should prefer (in-ns my-ns) over (ns my-ns) when I just want to change the default namespace. The both say they create it if it doesn't exist.
10:30	mmcgrana	rhickey: np, thanks for your help
10:30	danlei	MarkVolkmann: i think, ns is more to create a namespace, e.g. at the top of your file, while in-ns is more for changing the current ns, creating it being just a convenience
10:31	rhickey	danlei: right, I think the point is it's not clear
10:31	rhickey	I'm thinking of renaming ns to defnamespace
10:32	danlei	maybe defns? but that would probably be to close to defn
10:32	MarkVolkmann	I'd suggest defns to keep it similar in length to other functions and using "ns" like other functions.
10:32	rhickey	danlei: we've discussed defns before, looks like plural defn
10:33	rhickey	I'd be fine with it, but that's the objection
10:33	kotarak	Oh please. Not the defns/defnamespace whatever disscusion. rhickey, please use simply defnamespace it's clear and one doesn't type it too often...
10:33	mmcgrana	is it bad style to use ns multiple times for the same namespace? For example, if the ns is defined over several files and there are java imports for each of the different files?
10:34	rhickey	kotarak: right, the other advantage is it is long, so less likely a target for use in repl
10:34	MarkVolkmann	Maybe def-ns.
10:34	danlei	well, i think, whatever it'll be named like, a "def" in front of it would be a good idea
10:34	rhickey	mmcgrana: yes, that's bad, use ns once in the file named for the namespace and in-ns in the others
10:35	rhickey	mmcgrana: because you don't actually get per-file imports anyway
10:35	mmcgrana	ok
10:35	rhickey	import imports into namespace
10:35	mmcgrana	right, i just meant to declare the import close to where they are used, so that its easier to know when I need to add/remove imports.
10:36	mmcgrana	but all the imports should just actually be declared at the one spot (ns is used for a namespace?
10:37	rhickey	mmcgrana: yes, so it documents the sources of names in the namespace, else one file will presume it can use a name another introduces in an import
10:38	danlei	btw. is there a way to un- use/refer a package?
10:38	danlei	aehm
10:38	danlei	namespace ;)
10:39	mmcgrana	ok
10:39	Lau_of_DK	rhickey: Did you catch my last question?
10:39	rhickey	use/refer isn't a link, it pulls current vars in. There is ns-unmap
10:39	rhickey	Lau_of_DK: you can ignore the #', it doesn't matter anymore
10:40	Lau_of_DK	k, thx
10:40	danlei	rhickey: yes, i meant something like ns-unap for everything i refer'ed from another ns
10:40	danlei	*unmap
10:40	rhickey	danlei: not yet
10:40	danlei	rhickey: ok, thanks
10:44	Lau_of_DK	user> tst
10:44	Lau_of_DK	[{:b 4, :a 1} {:b 5, :a 2} {:b 6, :a 3}]
10:45	Lau_of_DK	If I want to grab the entry where b = 5. How do I do that idiomatically? (word?)
10:45	bottleneck	i have 2 maps with {word: count} pairs, i want to merge them. some words occur in both and then i want to do word: count1 / (count1 + count2)
10:46	rhickey	(doc merge-with)
10:46	clojurebot	Returns a map that consists of the rest of the maps conj-ed onto the first. If a key occurs in more than one map, the mapping(s) from the latter (left-to-right) will be combined with the mapping in the result by calling (f val-in-result val-in-latter).
10:46	bottleneck	so 4 / (4+0) or 7 / (7+12)
10:47	rhickey	hmmm, clojurebot should do the arglists as well
10:48	rhickey	bottleneck: merge-with takes a function that will be used to combine entries
10:48	bottleneck	ah nice
10:48	bottleneck	how do i force float-division?
10:49	rhickey	bottleneck: use floats
10:49	rhickey	or cast with (float ...)
10:49	rhickey	or (double ...)
10:50	Lau_of_DK	Anybody got a take on that?
10:50	bottleneck	(defn assoc-inc [m k v]
10:50	bottleneck	(if (contains? m k)
10:50	bottleneck	(assoc m k (+ v (get m k)))
10:50	bottleneck	(assoc m k v)))
10:50	rhickey	Lau_of_DK: filter
10:51	bottleneck	is there a built-in way fo doing that?
10:51	bottleneck	(assoc-inc {1 2 3 4} 1 3) -> {1 5 3 4}
10:51	Lau_of_DK	thanks rhickey
10:52	rhickey	(assoc m k (+ (m k 0) v))
10:52	rhickey	gets rid of the if
10:54	rhickey	more generally, you'd want assoc-with a la merge-with
10:54	bottleneck	i dont get it
10:54	rhickey	bottleneck: (m k 0) == (get m k 0), that extra arg at end is default return if not found
10:56	bottleneck	ok
10:57	danlei	is there a way (without use of regexes) to get the namespace of a symbol out of the return value of resolve? like: (symbol-ns (resolve 'sym)) -> my-ns
10:58	mmcgrana	its in the metadata
10:58	mmcgrana	(:ns ^#'filter)
10:59	danlei	ah, ok
10:59	danlei	mmcgrana: thanks
10:59	mmcgrana	or: (:ns (meta (resolve 'filter)))
10:59	mmcgrana	np
11:02	notallama	this is weird. i made a prime number function, and it gets up to 46337 and then says "java.lang.RuntimeException: java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.Long (NO_SOURCE_FILE:0)"
11:03	notallama	< and > don't work with longs?
11:03	notallama	or =?
11:05	bottleneck	rhickey: can i merge-with with default?
11:05	bottleneck	(merge-with #(/ (float %1) (+ %1 %2)) {"you" 10 "are" 5 "sick" 1} {"you" 2 "no" 12})
11:05	bottleneck	{"no" 12, "are" 5, "sick" 1, "you" 0.8333333}
11:06	bottleneck	i want then for sick to be 1 / (1+0) -> 1
11:06	bottleneck	which it ebcome sby luck
11:06	bottleneck	wait
11:06	bottleneck	"are" should be 1 instead if 5 in the emrged map
11:30	danlei	ok, first try for unrefer. not really tested, but seems to work:
11:30	lisppaste8	danlei pasted "unrefer" at http://paste.lisp.org/display/70917
11:32	danlei	maybe i should take the ns as an argument too, but then, its more for interactive use
11:56	AWizzArd	How can one compile .clj files? Something like (compile-file ...)
11:59	bottleneck	if i want to map over a hash-map, is (for [x Map]...) the onyl way, ic ant use map?
11:59	Chousuke	(map fn (vals yourmap))
12:00	rhickey	bottleneck: you can use map, the mapping function will be passed map entries, which you can destructure with [k v] or use (key e) (val e)
12:00	AWizzArd	(map #(println %) {:a 10 :b 20})
12:01	rhickey	AWizzArd: map with side effects is not a good example
12:01	AWizzArd	it just produces a very strange result for me
12:01	Chousuke	works for me, in the repl
12:01	AWizzArd	it produces ([:b 20]\nnil [:a 10]\n nil) where \n is a newline
12:02	Chousuke	AWizzArd: that's just the repl not being quite synchronised
12:02	rhickey	map is a function, it returns a sequence of the return values, which for println are nil
12:02	AWizzArd	I am using the newest clojure.jar and also just checked out a fresh swank-cloujre
12:02	Chousuke	the return value is (nil nil) but it prints the vectors too
12:02	rhickey	if you care about the returns fine, if you just want side effects use doseq
12:02	AWizzArd	rhickey: sure.. but it should produce a different result
12:03	Chousuke	AWizzArd: it produces the correct result
12:03	Chousuke	AWizzArd: it just prints weird.
12:03	Chousuke	AWizzArd: if you want to foce it to print correctly, you need to use doall
12:03	AWizzArd	I will post a screenshot, one sec
12:03	Chousuke	force*
12:04	rhickey	it doesn't print weird, you've mapped a function with side effects, it returns a lazy seq and those effects are delayed
12:04	rhickey	AWizzArd: we know what you are seeing
12:05	Chousuke	AWizzArd: whenever you use a 'map with side-effects, you must remember to use 'doall or 'dorun. otherwise the results may be not what you want
12:05	lisppaste8	danlei annotated #70917 with "takes ns as argument, too" at http://paste.lisp.org/display/70917#1
12:05	rhickey	map is lazy, so the values aren't produced until needed, they are needed to print the result in the repl, thus the interleave of print result val, side-effect, print result, side-effect
12:06	AWizzArd	so this problem is maybe in emacs, displaying it in a wrong color?
12:07	rhickey	bottleneck: (map (fn [[k v]] [v k]) {:a 1 :b 2 :c 3})
12:07	rhickey	([2 :b] [3 :c] [1 :a])
12:08	AWizzArd	How can one compile .clj files? Something like (compile-file ...)
12:08	rhickey	user=> (map val {:a 1 :b 2 :c 3}) ;same as vals
12:08	rhickey	(2 3 1)
12:08	rhickey	AWizzArd: you can compile namespaces with (compile 'my.ns.lib)
12:09	rhickey	the class files will be put in compile-path, and both the source root and compile-path must be in the classpath
12:09	AWizzArd	oki thx
12:11	danlei	does anybody see anything suspicious in unrefer? if not, i'll add it to my toolbox
12:15	rhickey	danlei: a few things, first, you are getting map entries which you should treat as such - first and frest are suspect, use key/val etc. Second, you should do find-ns once in a let
12:17	danlei	rhickey: ok, thanks. i understand the key/val issue, but why should i do find-ns in a let, if it's called only once?
12:19	rhickey	danlei: it's not called only once, but every step of the filter
12:19	danlei	rhickey: ah, stupid me. sure
12:20	notallama	i posted about my prime number sieve problem. i found the issue, but it turns out that sorted-set doesn't make a nice priority queue due to lack of custom comparator. any ideas for a way around this?
12:25	lisppaste8	danlei annotated #70917 with "destupidized version" at http://paste.lisp.org/display/70917#2
12:25	lisppaste8	bottleneck pasted "merge-maps problem" at http://paste.lisp.org/display/70919
12:25	bottleneck	^^ why does it return {}, i suppose im not handling let correctly
12:27	bottleneck	(defstruct word :ham :spam)
12:28	rhickey	bottleneck: how about a doc string? - would help us know what the function is trying to do
12:29	rhickey	danlei: you need to lift find-ns, not ns-map/mappings, which only happens once
12:30	danlei	rhickey: wtf ... i think i need some sleep. thanks
12:33	lisppaste8	bottleneck annotated #70919 with "example" at http://paste.lisp.org/display/70919#1
12:33	AWizzArd	http://clojure.googlegroups.com/web/http-client.clj makes use of gen-and-load-class. I think this exists no longer. Is genclass the new replacement?
12:34	AWizzArd	gen-class
12:34	rhickey	bottleneck: did you look at merge-with?
12:34	lisppaste8	bottle annotated #70919 with "asa" at http://paste.lisp.org/display/70919#2
12:34	bottleneck	merge-with: yes but i didnt get how to handle the caes where one isnt in the other
12:36	lisppaste8	bottle annotated #70919 with "dsdsd" at http://paste.lisp.org/display/70919#3
12:36	rhickey	bottleneck: you have to remember that the data structures are immutable, and that map/assoc etc return new values that you have to keep track of, they don't work by side effects
12:37	lisppaste8	danlei annotated #70917 with "schwere geburt" at http://paste.lisp.org/display/70917#3
12:37	danlei	i think i'll get some coffee ... start feeling stupid :) thanks for the tips
12:38	bottleneck	so reduce instead of map
12:41	hiredman	AWizzArd: it uses gen and load for ssl stuff
12:42	hiredman	I would recommend grabbing xlightweb and driving that with clojure
12:42	AWizzArd	oh oki, never heard of that before. Let me see...
12:43	AWizzArd	Btw, is there a java tool that allows me to operate firefox? I would like to do some automatic testing of a website, and it would cool to have something as close to a real browser as it can get.
12:43	hiredman	someone else here recommended it to me
12:44	AWizzArd	With running JavaScript and such
12:47	lisppaste8	asasa annotated #70919 with "dsfd" at http://paste.lisp.org/display/70919#4
12:47	bottleneck	rhickey ^^
12:55	Chouser	ah, shoot. paste.lisp.org actually does do a little something with its captcha.
12:57	Aisling	9
12:58	dthomas	Chouser: Thanks for printStackTrace last night, BTW. Didn't really solve my most hated problem, which is stack traces when working in SLIME being light on details, but it got me past the exception I was working on at the time.
13:00	danlei	omg ... another creation, only a mother could love. any ideas why my donut is so ugly?
13:00	lisppaste8	danlei pasted "ugly donut" at http://paste.lisp.org/display/70920
13:02	dthomas	Side SLIME/swank-clojure question: is slime-eval-defun supposed to eval in the NS appropriate NS for that point in the buffer? If my REPL is in "user" but the buffer starts with (ns some.package), eval-defun fails because (I'm guessing) it tries the defun in "user" (the REPL's NS).
13:04	Chousuke	dthomas: I think that's intended behaviour.
13:05	Chousuke	there is only one instance of clojure after all.
13:05	dthomas	Yeah, I seem to recall it worked this way when using SLIME with, say, SBCL.
13:05	dthomas	Does slime-eval-defun (C-M-x) eval in the correct Clojure namespace for others?
13:06	dthomas	Actually, I just realized that if I change the slime-repl's namespace to my.namespace first, it doesn't help: it still can't find some of the Java classes I've imported.
13:07	Chousuke	the repl namespace should be the same as in your other buffers, as long as you've evaled the ns setup expressions :/
13:07	Lau_of_DK	Good evening gents!
13:08	danlei	here is the page, i transcribed it from, no idea why mine looks so ugly: http://www.zetcode.com/tutorials/javagamestutorial/basics/
13:09	Chousuke	dthomas: at least for me, evaling import statements in a buffer also makes them available in the repl.
13:10	dthomas	Chousuke: I can eval the whole buffer, (ns) form included, and it works fine. I can see the NS in the REPL, just as it should be.
13:11	dthomas	Chousuke: But trying to evaluate with slime-eval-defun then fails to find classes that are imported in that NS, which makes me think it's evaluating in a different namespace than the one in the (ns) form at the top of the buffer.
13:12	bottleneck	http://paste.lisp.org/display/70919#4
13:12	bottleneck	noone can help
13:13	bottleneck	iff reduceing over a map cant i use when?
13:13	bottleneck	i have to use if-else
13:13	bottleneck	if i have a cond
13:13	bottleneck	?
13:13	Lau_of_DK	rhickey: I was wondering about the STM. As I recall you once made the argument, that locking gives terrible performance. What the difference between user locks, and the STM locks, dont they drag down performance as well ?
13:15	bottleneck	yes now it works
13:17	bottleneck	so this ia annoying
13:17	rhickey	Lau_of_DK: I never said locking gives poor performance, I may have said coarse-grained locks do
13:17	bottleneck	then i have to filter out afterwards
13:17	Lau_of_DK	rhickey: right, that might actually have been it
13:27	danlei	i'm googling for a java lib that lets me display notes, nothing fancy, i only just one system which i can put notes on. any tips?
13:28	danlei	*only need
13:29	danlei	(by notes, i mean musical notation)
13:30	Lau_of_DK	http://www.softsynth.com/links/java_music.html
13:31	danlei	Lau_of_DK: thanks, already plowing through ;)
13:34	danlei	Lau_of_DK: they all look kinda overkill to me ...
13:35	lisppaste8	Lau_of_DK pasted "Refs vs. Agents!" at http://paste.lisp.org/display/70921
13:36	Lau_of_DK	Could somebody please lend a hand with this. I think I might be misunderstand send-off. Youre supposed to identify a single pixel in the swarm my its id, so (get-pixel 1) returns the first with :id 1.
13:36	Lau_of_DK	So my idea was, that the agents state, would simply be this id.
13:36	Lau_of_DK	But something is not working, since they get corrupted after the first cycle
13:37	Chouser	every action you send to the agent needs to return their new state
13:37	Chouser	if you don't want the state to change, you need to return the old state
13:37	dthomas	OK, nevermind my SLIME problems, it seems that CVS SLIME within the past couple weeks must have fixed my problem.
13:38	Lau_of_DK	Which I believe the last 'a' in (behave) accomplishes, right Chouser?
13:40	danlei	ah, abc4j looks interesting
13:41	Chouser	Lau_of_DK: oh, sorry, didn't notice the paste. Did you try to list the errors the agent has?
13:42	Lau_of_DK	The error is "Agent has errors NO SOURCE"
13:42	Lau_of_DK	Can I get more than that?
13:44	Lau_of_DK	Got it working Chouser
13:45	Lau_of_DK	I couldnt get a more precise error, but I could strip the body, and rebuild it bit by bit
13:45	Lau_of_DK	the @ can be a bit confusing when nested
13:57	powr-toc	hey
13:57	Lau_of_DK	yo
13:57	powr-toc	Is there a reason why (+) returns 0 but (*) returns 1?
13:57	notallama	they return the identity.
13:58	kotarak	because 0 is the neutral element for +, and 1 for *
13:58	powr-toc	ahh, makes sense
14:00	thearthur	can i get a functions name?
14:00	thearthur	if somone passes a fun can i print its name?
14:01	kotarak	thearthur: functions don't have names.
14:01	kotarak	(fn [] :xxx)
14:01	kotarak	No name.
14:02	thearthur	some of them do
14:02	thearthur	if they where defined with defn no?
14:02	kotarak	No. There are names refering to functions. But the functions itself doesn't have a name.
14:05	powr-toc	Where is the doc function defined?
14:06	kotarak	powr-toc: in clojure.core namespace
14:06	kotarak	powr-toc: src/clj/clojure/core.clj
14:06	powr-toc	I have it in boot.clj
14:06	kotarak	Ok. That's all possible for pre rev1094 version.
14:07	kotarak	With revision 1094, the file was renamed.
14:09	powr-toc	ahh
14:09	powr-toc	Is there any idea on how long until 1.0 is expected?
14:13	Lau_of_DK	Is there anyway of testing the effectiveness of the STM in a given program of mine? Can the Javaprofilers help et?
14:13	Lau_of_DK	etc?
14:24	AWizzArd	How can one load/make use of downloaded .jar files?
14:25	lisppaste8	bottleneck pasted "bayesian spamfilter" at http://paste.lisp.org/display/70929
14:26	kotarak	AWizzArd: download .jar; export CLASSPATH=$CLASSPATH:file.jar; have fun :)
14:26	bottleneck	^^ 4 functions to make a spamfilter, nice! however im sure i can make it more elegant, merge-maps should be a lot shorter and clearer
14:27	danlei	AWizzArd: you can check your classpath from the repl with: (System/getProperty "java.class.path")
14:27	AWizzArd	ah gut
14:27	danlei	keine ursache
14:31	bottleneck	ja bitte und guten tag
14:32	bottleneck	no opinions ony my spamfilter?
14:33	AWizzArd	I can add anything to the environment variable CLASSPATH under Windows Vista, this (System/getProperty "java.class.path") always returns "clojure.jar". That does not sound right, right?
14:35	danlei	AWizzArd: for me it's: "/home/danlei/build/clojure/trunk/target/clojure-lang-1.0-SNAPSHOT.jar:/home/danlei..."
14:36	Lau_of_DK	Can somebody tell me how this is done in these terrible AOT times: http://rpdillon.googlepages.com/creatingexecutablejarswithclojure
14:36	danlei	AWizzArd: i've heard, that the classpath environ variable is not used, when a classpath is given via -cp, but i'm not sure about it. try adding it with (add-classpath "file:///C:/path/to/file.jar")
14:37	danlei	AWizzArd: if you're running slime, add the path to swank-clojure-extra-classpaths
14:41	lisppaste8	kotarak pasted "rescue for Lau" at http://paste.lisp.org/display/70930
14:42	Lau_of_DK	uuuuh
14:42	Lau_of_DK	Thanks alot Mr. Kota - You saved the day
14:42	kotarak	Lau_of_DK: np :)
14:48	Lau_of_DK	but Mr. Kota..
14:48	Lau_of_DK	This effectively means, that I must rename ALL my functions to my namespace :\|
14:50	kotarak	?? Do you mean the new -form?
14:50	Lau_of_DK	oh...
14:50	Lau_of_DK	I started with (ns 'lbj.core.Langdon)
14:51	kotarak	without ': (ns lbj.core.Langdon)
14:51	Lau_of_DK	so I figured everything must be (defn lbj.core.Langdon-func)
14:51	Lau_of_DK	yea
14:51	Lau_of_DK	mistake
14:51	kotarak	No. In this namespace simply (defn -foo ..) (defn -bar ...)
14:51	Lau_of_DK	k
14:51	kotarak	The Classname is not needed anymore.
14:56	Lau_of_DK	So basically, every single variable, function, constant, whatever, in every single problem I write, must be prefixed with -, for the reader to understand that its in the same ns ?
14:56	kotarak	No.
14:57	kotarak	-foo in namespace foo.bar.Baz is the method foo of class foo.bar.Baz as in (.foo (new foo.bar.Baz))
14:58	bottleneck	1. is there some database stuff shipping with Clojure or what is the easiest way to set up and use a database? 2. is there a lib that lets me start mp3s ?
15:01	Lau_of_DK	kotarak: thats basically the same thing
15:02	Lau_of_DK	everything in that namespace must be prefixed with -
15:02	kotarak	If everything is a method then yes. "Normal" functions, don't have to be prefixed.
15:02	albino	bottleneck: use JDBC and do the java thing as far as databases are concerned
15:03	kotarak	(ns foo.bar.Baz (:gen-class ...)) (defn bar [x] (+ x 2)) (defn -foo [a-number] (bar a-number))
15:03	Lau_of_DK	kotarak: Explain the difference between method and function please
15:04	kotarak	A method is part of the class as in (.methodName clase-instance). A function is a "normal" Clojure function.
15:04	kotarak	s/clase/class/
15:04	Lau_of_DK	k
15:07	notallama	are methods java mathods? like, if i compile with a fn called -bar, can i go into java, import it, and say "foo.bar()"?
15:08	kotarak	notallama: you have to declare a class with :gen-class. There you can specify, that your class has a method bar and then you can basically do that. Yes.
15:11	notallama	awesome. i'm going to have to figure out how this works.
15:11	kotarak	(doc require)
15:11	clojurebot	Loads libs, skipping any that are already loaded. Each argument is either a libspec that identifies a lib, a prefix list that identifies multiple libs whose names share a common prefix, or a flag that modifies how all the identified libs are loaded. Use :require in the ns macro in preference to calling this directly. Libs A 'lib' is a named set of resources in classpath whose contents define a library of
15:12	kotarak	upsala.
15:12	kotarak	notallama: you might be interested in [doc gen-class] with (). (Don't what clojurebot does. It's a bit long...)
15:15	lisppaste8	Chouser pasted "my test macro" at http://paste.lisp.org/display/70931
15:16	Chouser	clojurebot: macro help is http://clojure-log.n01se.net/macro.html
15:16	clojurebot	Ack. Ack.
15:16	Chouser	clojurebot: macro help?
15:16	clojurebot	macro help is http://clojure-log.n01se.net/macro.html
15:18	kotarak	Chouser: thumbs up
15:19	rhickey	Chouser: awesome!
15:20	Chouser	cheap hack, actually, but anyway...
15:20	Chouser	you have to fill out the captcha after you submit the form -- an extra step.
15:21	kotarak	Chouser: the right way: poka-yoke
15:23	Chouser	:-)
15:29	bottleneck	1. is there some database stuff shipping with Clojure or what is the easiest way to set up and use a database? 2. is there a lib that lets me start mp3s ?
15:30	Chouser	1. Java comes with JDBC. There is also clojure.contrib.sql
15:30	Chouser	2. I think Java comes with audio playback libs.
15:35	bottleneck	jdbc? i want something that abstracts away all the annoying sql syntax
15:35	bottleneck	like: insert stuff table row col
15:35	bottleneck	and not allt hat extra shite
15:37	Chouser	bottleneck: ah, yes, that would be nice. The idea has come up, but I'm not aware of any implementation.
15:39	kotarak	There is schemeql, but I don't know, whether it's easy to port and whether it is worth the trouble..
15:42	Chouser	I'd love to see something like (select my-col from my-table where id-col = ~id) -> [{:my-col "foo1"} {:my-col "foo2"}]
15:42	bottleneck	hmm link?i might cuz it looks like im going with clojure
15:42	Chouser	but I haven't thought it through much.
15:42	kotarak	Chouser: schemeql is something in this way.
15:43	kotarak	But I never used it and don't know it state.
15:48	Chouser	SchemeQL link: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.11.4048
15:52	Chouser	looks about right to me
15:58	jgracin	I never found any sources of SchemeQL
15:58	jgracin	source code, I mean
15:59	Lau_of_DK	Chouser: how do I test the effeciency of the STM in any program of mine?
16:02	Chouser	effeciency? If you mean overall performance, I suppose you would create something that puts your program under realistic or extreme load, and measure how it performs.
16:06	Lau_of_DK	I mean, how many transaction had to be retried, average re-try rate. That type of thing.
16:10	Chouser	oh! There's no "standard" way yet, as far as I know.
16:10	Chouser	Perhaps you could add a logging call to the dosync macro and collect stats that way.
16:12	bottleneck	why does both succeeding imports and failing ones return nil?
16:13	powr-toc	Lau_of_DK: There's a nice low ceremony java ORM for JDBC, called ActiveObjects... It's OO, so it's not the functional wrapper you're looking for, and I have no idea how it'd translate into clojure; but it might be worth a look as a last resort
16:13	powr-toc
16:13	dthomas	bottleneck: What is a failing import?
16:14	dthomas	bottleneck: When I try to (import) something that doesn't exist I get a ClassNotFoundException.
16:15	bottleneck	(import '(java.jdbc))
16:15	bottleneck	nil
16:15	bottleneck	(import '(java.jdbcsdcscc))
16:15	bottleneck	nil
16:16	dthomas	bottleneck: Ah, OK.
16:16	cooldude127	bottleneck: you can't just import a whole package in clojure i think
16:17	dthomas	I suspect you don't need to import a package when you use a fully-qualified name.
16:17	cooldude127	correct
16:19	dthomas	I wonder if Java even offers a way to introspect a "namespace" (or "package" or whatever they'd like to call java.sql).
16:19	bottleneck	so hiw do i do?
16:20	dthomas	I guess that's java.lang.Package. I see Package/getPackage itself returns null instead of raising an exception when given a bogus package name.
16:21	dthomas	bottleneck: What are you trying to accomplish? If you want to use things in java.sql by their fully qualified name you can just use them. E.g. java.sql.DriverManager.
16:22	AWizzArd	When I do (System/getProperty "java.class.path") I get back "c:/Users/ath/clojure/clojure.jar" under Windows Vista. Now I say (add-classpath "file:///Users/ath/clojure/libs/xLightweb/xlightweb-2.2.1-jar-with-dependencies.jar") and it returns nil. But when I check the classpath again via (System/getProperty "java.class.path") nothing has changed. Is that normal? Doesn't this get updated?
16:25	dthomas	AWizzArd: I observe the same behavior here. My guess is that java.class.path is set at JVM bootstrap time and from then on it's just the ClassLoader using that path.
16:26	dthomas	Er, that is, I'm betting the ClassLoader reads that property when it's constructed, and further modifications to it are ignored.
16:26	dthomas	I note that when I (add-classpath) something, I can't (import) it but I can refer to classes from that JAR.
16:26	AWizzArd	how do you refer to them?
16:28	dthomas	AWizzArd: Fully qualified name. Like I just loaded a JAR and then tried just "org.w3c.util.URLUtils" in the REPL
16:32	Lau_of_DK	So Im reading through the ClojureGroup, and suddenly there are entire posts in French... w00t?
16:33	kotarak	Yeah, instead of discussing in english whether the language matters, they do it in french, excluding external opinions.
16:34	Lau_of_DK	Cant we add a filter for french? My mind has one built in :)
16:53	danlei	is there a way to make the prompt show only the last part of the ns? foo.bar.baaz.quux> -> quux>
16:53	danlei	s/./-/g
16:55	AWizzArd	danlei: you would have to supply your own repl
16:55	AWizzArd	the p part prints the full ns thing (default)
16:55	AWizzArd	your print would not
16:56	danlei	AWizzArd: ok, thanks, AWizzArd
16:56	arohner	If you look at Repl.java, the prompt is hard coded
16:56	arohner	it would be pretty simple to replace that with a var that points at a fun
16:56	danlei	yes, that shouldn't be hard. just wanted to know, if there's a standard way to tweak it
16:59	AWizzArd	in Common Lisp you "program" your own Lisp interpreter by saying: (loop (print (eval (read))))
17:00	AWizzArd	that will not give any output prompt.. but into this structure you could put your own prompt
17:00	arohner	the musings on the google group about rewriting the repl in clojure look interesting
17:01	danlei	i should start reading the group more regularly
17:01	Lau_of_DK	I second that
17:01	AWizzArd	you can simply build your own repl on top of the existing one
17:01	AWizzArd	in this meta repl you can do whatever you want
17:02	danlei	i understand
17:12	flaskan	dthomas:ok, im new to databases, how do i create database? is their one coming with java or i have to download postgresql or mysql separately and install?
17:12	Chouser	So far I've written a Clojure REPL in Clojure for the browser and for Swing. Someone else wrote one in Clojure for Qt.
17:13	dthomas	flaskan: AFAIK J2SE JDK doesn't come with any databases, so you'll probably need to have a database and then the JDBC driver for it.
17:13	kotarak	I use a Clojure Repl for Gorilla. But heavily modified in many ugly ways to sync with Vim.
17:16	Chousuke	flaskan: if you want an easy way to make a simple database, you could try sqlite
17:17	Chousuke	it doesn't require any complex server setups so it should be good for experimentation :)
17:17	tWip	I think JDK6 comes with derby
17:19	tWip	http://java.sun.com/developer/technicalArticles/J2SE/Desktop/javase6/beta2.html
17:19	dthomas	flaskan: I second Chousuke's recommendation pretty much. I just compiled http://www.xerial.org/trac/Xerial/wiki/SQLiteJDBC the other day.
17:19	tWip	under database... but don't use it for production :)
17:20	dthomas	I'm actually kind of scared by the number of pure Java SQL databases available with a quick web search.
17:22	dthomas	Never really looked at Derby, looks kind of nice. It seems to support foreign keys, which I sometimes miss in SQLite. Also supports multiple connections to the DB from within the same JVM, which I was having problems with in conjunction with the above SQLite JDBC driver.
17:22	tWip	yeah, I think bundling derby pretty much solved the testing of jdbc apps
17:23	tWip	no need for sqlite
17:52	flaskan	Chousuke: how do i connect it to my program?
17:57	Chousuke	flaskan: that shouldn't be too difficult with JDBC. I'm sure you'll find examples if you do some googling.
17:58	flaskan	tWip: how do i access derby from clojure? is the database itself there too so i dont need to install anything?
17:58	flaskan	i cant even understand how do they made java so complicated.
17:58	blackdog_	flaskan, have a look in contrib.sql
17:58	blackdog_	in tests there is an example
18:07	flaskan	i see
18:07	flaskan	i have contrib in C:/clojure_20080916/clojure-contrib
18:07	flaskan	but i never got how to install it so i cant use it
18:08	arohner	flaskan: source or jar?
18:27	flaskan	source
18:33	flaskan	where is that link to setup slime?
18:33	flaskan	http://github.com/jochu/swank-clojure/tree/master/swank-clojure.el
18:33	flaskan	is that enough?
18:37	hiredman	clojurebot: (* 34 23)
18:37	clojurebot	I don't understand.
18:37	hiredman	damn you
18:37	hiredman	(* 34 23)
18:37	clojurebot	782
18:41	danlei	(+ 1 2)
18:41	clojurebot	3
18:41	danlei	(prn 'hello)
18:41	danlei	nice
18:42	flaskan	(pr "clojurebot is a donkey")
18:43	flaskan	(eval '(+ 1 2))
18:43	arohner	is there a way to make swank pretty print a macroexpand?
18:43	danlei	clojurebot: clojurebot?
18:43	clojurebot	clojurebot is self referential
18:44	hiredman	just math right now
18:46	hiredman	and only simply stuff, no nested expr
18:47	danlei	is there a function that: (?? [a b c d]) -> [b c d a] -> [c d a b]
18:47	danlei	"rotates"
18:48	flaskan	(+ 3 4)
18:48	clojurebot	7
18:48	Chouser	clojure.contrib.lazy-seqs/rotations
18:48	flaskan	(- clojurebot life)
18:49	danlei	Chouser: great thanks
18:49	flaskan	chouser: cool
18:49	flaskan	i want to setup SLIME for windows, can someone post a link?
18:49	Chouser	(apply + 1 2 3)
18:49	flaskan	i think remember seeing one
18:49	Chouser	(+ 1 2 3)
18:49	clojurebot	6
18:49	flaskan	or how do i do it?
18:50	danlei	flaskan: i remember some podcast, but maybe that was for os x
18:50	flaskan	but slime is just a bunch of el-files right?
18:50	flaskan	so i need to what, run it with clojure as inferior-lisp?
18:51	danlei	well, you'd need swank-clorure and stuff, it's described on the wiki
19:00	danlei	hm, i think i'm a little confused ... what does (require 'foo.bar) (refer 'foo-bar) become in ns?
19:00	dthomas	I'm a bit surprised that 0 is apparently true. Is this right?
19:01	rhickey	danlei: use
19:02	rhickey	dthomas: 0 is not nothing (nil), nor false
19:02	flaskan	rhickey: on homepage, Slow/no innovation post standardization, slow as in slow execution speed? sbcl is superfast...
19:02	powr-toc	does anyone know in which java files the built-ins are defined (e.g. if, let etc...)
19:02	rhickey	flaskan: slow innovation, not execution :)
19:03	flaskan	ah yes i read like a donkey
19:03	rhickey	powr-toc: clojure.lang.Compiler
19:03	danlei	rhickey: ok, (:use (foo.bar) (baz.quux)) seems to work. is that correct (the parens)
19:04	powr-toc	rhickey: thanks... was looking in there, but somehow skipped past them.
19:05	danlei	nice, works
19:07	dthomas	rhickey: OK, I guess I see where that's documented both in the section on the reader and the "Differences with Lisps" page. Thanks.
19:08	rhickey	dthomas: 0 is true in Common Lisp too
19:09	dthomas	rhickey: Huh, so I just tested. That's kind of embarassing that I didn't know that.
19:09	dthomas	(And now immortalized in IRC logs.)
19:11	dthomas	Too bad in this case, since I wanted to do (or (compare a b) (compare c d)).
19:16	flaskan	clojure-lang-1.0-SNAPSHOT.jar
19:16	flaskan	what is that?
19:18	flaskan	path tot e clojure.jar?
19:18	flaskan	why snapshot?
19:20	flaskan	i got wokring a bit, both clojure and slime in the menu
19:20	flaskan	but i cant run inferior lisp
19:22	notallama	point it to your clojure.jar. (whatever yours is called)
19:22	flaskan	in did
19:22	flaskan	i did
19:22	arohner_	flaskan: what do you mean "can't run?" what happens when you do M-x inferior-lisp?
19:22	flaskan	no such filem or directory, lisp
19:23	flaskan	(setq swank-clojure-jar-path "C:/clojure_20080916/clojure.jar")
19:23	arohner_	if you are trying to run slime, you should use M-x slime rather than M-x inferior-lisp
19:24	powr-toc	Is there a reason why the special-forms like if, let etc... don't have meta-data associated with them? I'm thinking doc strings etc...
19:25	powr-toc	as a newbie, it occaisionally seems frustrating to do (doc new) and get an error
19:26	arohner_	powr-toc: SVN clojure supports (doc <special form>)
19:26	powr-toc	ahh cool
19:26	powr-toc	I'll upgrade
19:26	arohner_	it only tells you to go read clojure.org though
19:26	flaskan	ok i got it running wioth M-x slime but it doenst sem to fucntion poerfectly. for some reason I cant do C-c C-e(its grey in the menu)
19:26	powr-toc	lol
19:27	arohner_	flaskan: you have a repl?
19:27	flaskan	why are the keybindings for clojure-mode no in the menu? why are the keybindings for slime grey, ie not working?
19:28	arohner_	flaskan: did you install clojure-mode?
19:28	arohner_	go to a .clj file and type M-x clojure-mode
19:28	notallama	flaskan: have you looked at http://riddell.us/clojure/ ? that helped me get it working.
19:29	arohner_	or http://en.wikibooks.org/wiki/Clojure_Programming#Emacs_.2F_Slime_Integration
19:29	flaskan	aroherr: yes repl
19:29	flaskan	^^ im doing that
19:30	flaskan	i have clojure and slimem in the emacs-menu, the clojure-repl is running with M-x slime
19:30	flaskan	but the keybindings are not working
19:30	danlei	ok, something must be wrong. is this correct use: (ns ... (:use (foo.bar) (baaz.quux)) ... ?
19:31	flaskan	in normal clojure-mode i can do C-c C-e to eval last s-expr, now i ahveto choose with the mouse in the clojrue-menu. the binding is in the slime-menu but it is grey, ie not activ eor something
19:31	flaskan	using windows btw
19:32	arohner_	try C-x C-e
19:34	danlei	i don't get it; (require 'foo.bar) (refer 'foo-bar) works perfectly fine ...
19:34	notallama	i have that same issue on my windows box. i'm thinking it's because i screwed up the setup. i'll try fixing it afte i' done my homework, and let you know how it goes if you don't get it working by then.
19:36	flaskan	user=> java.lang.Exception: No such namespace: swank
19:36	flaskan	the repl starts but i get that ^^
19:36	arohner_	flaskan: I've seen that when the clojure and swank versions don't match up. If you have a pre-AOT clojure, you'll need a pre-AOT swank, and vice versa
19:37	arohner_	you are using the downloaded clojure.jar?
19:37	flaskan	ahead of time compilatioN?
19:37	arohner_	flaskan: yes
19:37	flaskan	dont know i have the september 16 version
19:37	arohner_	and you git clone'd swank?
19:39	flaskan	yes
19:39	flaskan	both swank and clojure-mode i git-cloned
19:39	arohner_	run this:
19:39	arohner_	git reset --hard 73625153203649bb9bac1a32774e1100a60c6f5c
19:39	arohner_	inside your swank-clojure directory
19:39	arohner_	then restart emacs
19:40	arohner_	that will point your swank to an older version which should work with the sept clojure
19:42	flaskan	user=> java.lang.Exception: No such var: swank/start-server
19:42	flaskan	etc
19:42	flaskan	still the same problem
19:42	arohner_	hrm. That's the exact version I'm using on an older clojure version
19:43	danlei	ok, one more time. can someone give me a sample invocation of "use"? neither (use 'foo.bar), (use 'foo-bar) (use '(foo.bar)) (use '(foo-bar)), nor 20 other possible combinations i tried seem to do the trick. can't be that hard
19:44	arohner_	danlei: (use 'clojure.contrib.test-is)
19:44	arohner_	if that doesn't work, it probably means the library you want is not in the classpath
19:45	flaskan	anyway f*** slime. couldnt someone put up a guid eon how to do java classpath stuff on windows, how to make it work with clojure?
19:45	danlei	well, it works, if i do (require 'foo.bar) (refer 'foo-bar)
19:45	danlei	but not with (use 'foo.bar)
19:45	arohner_	danlei: how does it not work?
19:45	Chousuke	aren't you supposed to use the ns macro instead of those anyway?
19:45	danlei	namespace foo.bar not found
19:46	danlei	well, i wanted, but that won't work either
19:46	danlei	i'm sure it's just a small glitch, but i don't get what's wrong
19:46	Chouser	danlei: it may be your file structure
19:47	danlei	ok
19:47	danlei	look:
19:47	arohner_	flaskan: use -cp when starting java
19:47	Chouser	danlei: what's the full name of your namespace?
19:47	arohner_	java -cp /path/to/clojure-contrib.jar clojure.lang.Repl
19:48	danlei	dhl-utils
19:48	Chousuke	that's missing clojure.jar though :p
19:48	arohner_	oops, need a clojure.jar in there
19:48	danlei	they live in .../clojure/dhl/utils.clj
19:48	danlei	and ... is in the classpath
19:48	arohner_	java -cp path/to/clojure.jar:/path/to/clojure-contrib.jar clojure.lang.Repl
19:48	danlei	sorry .../clojure/ is in the claspath
19:48	Chousuke	danlei: that's misnamed then, isn't it?
19:48	Chouser	ok, with that file structure your namespace should be clojure.dhl.utils
19:49	Chouser	ok, then dhl.utils
19:49	rhickey	flaskan: maybe you want to try this: http://groups.google.com/group/clojure/msg/5f4d2779717e6b26
19:49	danlei	even if .../clojure/ is in the classpath?
19:49	danlei	yes, ok
19:49	cooldude127	is anybody else reasonably familiar with On Lisp's non-determinism macros? (choose, fail)
19:49	danlei	i just double-checked it's definitely in the classpath, and i spelled everything correct
19:50	danlei	if i do (require 'dhl.utils) (refer 'dhl-utils) everything works as expected
19:50	Chouser	so with your
19:50	Chouser	no
19:50	danlei	then: use 'dhl.utils ->
19:50	danlei	namespace dhl.utils not found
19:51	Chouser	if (refer 'dhl-utils) works, then your namespace is named dhl-utils when it should be dhl.utils
19:51	danlei	aha
19:51	danlei	just a sec, i'll check
19:51	cooldude127	CLOJURE WHY CAN'T YOU JUST HAVE CONTINUATIONS
19:52	cooldude127	I KNOW IT'S NOT YOUR FAULT
19:52	cooldude127	sorry guys :)
19:53	danlei	Chouser: Thou art a saint. Thank thee!
19:53	danlei	i almost went mad
19:53	Chouser	danlei: np. subtle one there. :-)
19:53	danlei	oh boy
19:55	powr-toc	cooldude127: vaguely... they implement failure driven search right?
19:55	bradbev	does anybody know where the best place to post patches for clojure/swank?
19:56	powr-toc	like prolog style backtracking etc...
19:57	arohner_	bradbev: fork it off github, and then commit to your fork
19:58	bradbev	arohner_: true. I guess that's easier than posting patches to the main tree then?
19:59	arohner_	are you asking about clojure proper, or swank-clojure, or both?
19:59	bradbev	swank-clojure
20:01	arohner_	ok, yeah. what I said above. the process is different for clojure proper and for a second I thought you were asking about htat
20:02	cooldude127	powr-toc: exactly
20:03	cooldude127	i'm trying to port those to clojure
20:03	cooldude127	it's only going somewhat well
20:03	bradbev	arohner_: thanks
20:03	arohner_	np
20:05	cooldude127	powr-toc: it works, but the problem with it is that if you reach a solution before you've tried them all, the possibilities are still left around, they don't get removed
20:06	cooldude127	it makes me sad
20:07	flaskan	rhickey: thanks for the link, seems awesome
20:07	flaskan	really very good initiative
20:07	Chouser	cooldude127: doesn't 'on lisp' include macros for making continuations out of closures?
20:09	cooldude127	yeah it does, i need to look at them, still haven't wrapped my head around how that can work
20:10	Chouser	does anyone think there's a niche for very small standalone text editor + clojure repl written in pure clojure? It'd be very small and require essentially no installation, but it's getting to be a crouded space with slime, clojurebox, enclojure, gorilla, jedit plugin, eclipse plugin, etc.
20:11	danlei	Chouser: if it would be a one-click installer, everything included that one needs to get a repl, without classpaths and all that stuff, there would surely be a niche
20:12	danlei	i mean ... about 8-10 /long/ discussions just about such stuff in the last few days
20:13	Chouser	danlei: yeah, I think it could be a single .jar which, if I understand correctly, could be double-clicked in Windows and MacOS. Launching in any Linux would be a one-liner at worst.
20:13	danlei	Chouser: i'm sure that peope would use it
20:13	danlei	+l
20:13	flaskan	a
20:13	MarkVolkmann	Darn! I asked this question this morning and I already forgot the answer! ...
20:14	lisppaste8	flaskan pasted "bayesian spamfilter" at http://paste.lisp.org/display/70940
20:14	MarkVolkmann	I have a list and I want to use the values and arguments to a function. What expands a list in place so the items in it can be treated as individual arguments?
20:14	Chouser	MarkVolkmann: apply
20:14	flaskan	does anyone know how to make the merge-and-compute... function smaller?
20:14	MarkVolkmann	Thanks!
20:15	flaskan	Chouser: id be interested in the code but not really using it
20:15	Chouser	flaskan: heh, ok.
20:17	cooldude127	Chouser: might be nice for those new to the language or those unattached to their editor
20:17	cooldude127	but for me, emacs is it
20:18	MarkVolkmann	Why doesn't this print all the arguments on separate lines?
20:18	MarkVolkmann	(defn prn-all [& args] (apply prn args))
20:18	danlei	that's what i thought, too. imagine being a total newbie, never used emacs or stuff. then you've got to get java, clojure, contrib(?), set classpaths up, install slime, make that work with swank-clojure, ... it's quite something a starter has got to get working
20:19	MarkVolkmann	When I run (prn-all 1 2 3), all the values are output on the same line, but prn is supposed to include a newline after each call.
20:19	arohner_	MarkVolkmann: because you call prn once with [args]
20:19	danlei	(and emacs alone may be fairly intimidating to some)
20:19	flaskan	anyone using clojure-box? it works perfectly, i just dont get which .emacs file it uses. i want to take away the toolbar, how?
20:19	MarkVolkmann	How can I make my prn-all function call it once for each argument?
20:19	arohner_	try (defn prn-all [& args] (doseq [x args] (prn x))
20:20	cooldude127	well here does, now i'm giving clojure continuations
20:20	MarkVolkmann	I'm confused why apply didn't do that. Isn't it supposed to call the function prn once for each item in the args list?
20:20	danlei	flaskan: you're talking about the emacs toolbar?
20:21	arohner_	flaskan: i don't know where the .emacs file is, but you can get rid of the toolbar by eval'ing (if (fboundp 'tool-bar-mode) (tool-bar-mode -1))
20:21	cooldude127	MarkVolkmann: you're thinking of map
20:21	arohner_	prn by itself takes any number of arguments, prints them, and then prints one newline
20:22	arohner_	try (prn 1 2 3)
20:22	cooldude127	apply basically the list you pass as the last argument and makes each element an argument
20:22	arohner_	apply calls the function you supply, once
20:22	MarkVolkmann	Ah, okay. I guess I need to use doseq to call a function once for each item in a sequence.
20:23	arohner_	right
20:26	cooldude127	wow the doc macro makes me super happy
20:31	flaskan	when using clojure-box, is it then possible to do sql stuff without installing anything else?
20:32	danlei	any musicians here?
20:32	flaskan	im trying to write a genetic programming music program in clojure
20:32	flaskan	but no i suck at music unfortuenwately
20:32	danlei	hm
20:33	cooldude127	Chouser: you seem to know what's going on when it comes to idiomatic clojure. so when it comes to these continuation and non-determinism macros, we have some global state. is this a situation for refs or vars?
20:33	danlei	how would you model generation of scales/arpeggios and stuff
20:33	danlei	i did it like this:
20:33	danlei	keep chromatic scale in a vector
20:33	danlei	and the scales, for example are the number of half-steps (relative to each oher)
20:33	danlei	then, i map those over the chromatic scale from the tonic
20:34	danlei	so that i can create scales/arpeggios and that stuff without having a large database of such stuff
20:36	danlei	at least it works, kinda :)
20:38	cooldude127	you gotta love clojure's approach to mutable state until it makes your life a pain in the ass
20:38	lisppaste8	Chouser annotated #70940 with "shorter merge-and-compute... for flaskan" at http://paste.lisp.org/display/70940#1
20:41	Chouser	cooldude127: vars are fine if all the mutation is going to happen within a single thread -- changes will be invisible to other threads and thrown away when the thread completes.
20:41	Chouser	cooldude127: chances are you want a ref
20:43	cooldude127	Chouser: ok, well now i have new challenges, as i'm not sure how to implement these continuation macros with refs
20:44	Chouser	cooldude127: you're sure the state mutates, right? Sorry, it's been ages since I looked at 'on lisp'
20:44	cooldude127	well, the paths variable gets stuff added to it whenever you do a choose
20:45	cooldude127	i'm not really sure about the continuation variable, looks like all it does is get rebound
20:45	cooldude127	but the way it does is weird, he uses it as the name of the first argument to functions
20:45	Chouser	sorry, gotta go -- back in a few...
20:45	cooldude127	NOOOOO
20:45	cooldude127	k
20:52	bradbev	what's the best way to see if an argument is a function? I feel like I want (function? x) or (callable? x)
20:52	bradbev	fn?
20:52	bradbev	doh
20:53	cooldude127	yay
20:53	cooldude127	lol
20:54	Chouser	bradbev: note that (fn? {}) -> true
20:54	cooldude127	yeah anything that can be called like a function gets to return true
20:54	bradbev	yeah, same for vectors etc
20:55	cooldude127	and keywords even
20:58	powr-toc	Is that why vectors etc... implement java.lang.Runnable?
20:58	cooldude127	probably
20:58	powr-toc	Is it just a side effect of them being functions?
20:58	cooldude127	everything in clojure implements everything even remotely possible
20:58	bradbev	coming from CL, I am starting to like how easy it is to call functions is a Lisp-1
20:58	bradbev	in a Lisp-1
20:58	cooldude127	yeah it's so nice and clean
20:59	Chouser	cooldude127: ok, so he's capturing cont all over the place
20:59	danlei	i often name my vars as functions ...
20:59	cooldude127	yes
20:59	cooldude127	Chouser: i'm not sure how to translate the lambda captures to refs
21:00	danlei	took me almost 10 minutes to find a bug (let [seq ...
21:00	cooldude127	do i even need refs for it?
21:00	Chouser	danlei: yeah, don't do that.
21:00	cooldude127	danlei: that's the only problem
21:00	powr-toc	cooldude127: I guess it makes sense, just wondering what it means to run a vector...
21:00	danlei	Chouser: yes, i know. it's just habits
21:01	Chouser	tempting names for locals that should be avoided: seq, list, vector, vec, fn
21:01	Chouser	str
21:01	Chouser	powr-toc: it takes an int, and returns the value at that index
21:02	cooldude127	powr-toc: all functions are runnable
21:02	Chouser	powr-toc: ([:a :b :c] 1) -> :b
21:02	MarkVolkmann	question about function documentation syntax ... look at (doc concat) as an example ...
21:02	cooldude127	powr-toc: they just do their thing
21:02	danlei	those things bite me quite often, a few hours ago, cond confused me to death, because of the removed parens =)
21:02	cooldude127	lol
21:02	MarkVolkmann	It says ([] [x] [x y] [x y & zs]).
21:02	cooldude127	MarkVolkmann: those are the 4 possible signatures
21:02	MarkVolkmann	Why not just & x.
21:02	cooldude127	optimization
21:02	MarkVolkmann	Doesn't that encompass all the possibilities?
21:03	MarkVolkmann	So the common cases are handled more efficiently?
21:03	cooldude127	yes
21:03	MarkVolkmann	That seems to be an implementation detail and not really part of the documentation of the function.
21:03	cooldude127	and it might use reduce to turn the multiple one into a bunch of calls to the two-arg variety
21:03	cooldude127	MarkVolkmann: could be true
21:04	cooldude127	are the docs autogenerated?
21:04	powr-toc	Chouser: yeah, I understand that... but Vectors are a function of their indexes... java.lang.Runnable#run() takes no params (though they could be instantiated via a constructor)... so I guess it's just a function of being a function...
21:04	cooldude127	i had not considered that
21:05	cooldude127	is rhickey here?
21:05	Chouser	powr-toc: ah, good point. yeah, IFn implements Runnable, but in any case where a function can't be run with zero args, that fact's not useful.
21:05	powr-toc	So I guess there's no use in it
21:05	cooldude127	apparently not
21:06	cooldude127	we could just try (.run [1 2 3])
21:06	cooldude127	could we not?
21:06	Chouser	cooldude127: the arg list doc is generated from the actual function signatures in most cases
21:06	cooldude127	yeah that's what i thought
21:06	powr-toc	Chouser: still... it's all elegant, right through to the java... I like it :-)
21:07	cooldude127	yeah (.run [1 2 3]) throws an exception
21:07	cooldude127	i don't think vectors specifically implement run by choice
21:07	cooldude127	it appears to delegate to function behavior
21:07	Chouser	cooldude127: I don't think you need a ref
21:07	cooldude127	Chouser: i was starting to think so
21:08	cooldude127	i still think i do for choose
21:08	cooldude127	but not for continuations
21:08	Chouser	oh, ok.
21:08	cooldude127	still not sure what the hell i'm doing
21:08	cooldude127	lol
21:08	Chouser	:-)
21:08	Chouser	well, good luck with it anyway.
21:08	cooldude127	thanks
21:09	cooldude127	it was so much easier in arc lol, of course graham would make it easy in his own language
21:09	rhickey	fns implement Runnable, but not all IFns do
21:09	cooldude127	rhickey: why do vectors?
21:09	MarkVolkmann	Yes, documentation of the arguments a function takes IS autogenerated. That explains why (doc concat) outputs what it does. It picks up on the optimizations.
21:10	rhickey	cooldude127: because their abstract superclass does
21:11	cooldude127	rhickey: sounds right
21:11	cooldude127	the exception calling run() on it throws indicates that
21:11	Chouser	IFn extends Runnable
21:13	flaskan	Chouser: cool, learned some new tricks from that
21:13	Chouser	flaskan: great!
21:13	Chouser	flaskan: I did that without actually understanding your algorithm or having a complete test case, so there may be other reductions available.
21:13	powr-toc	Looks like it should throw an IllegalArg...Exception due to the arity
21:14	cooldude127	powr-toc: run() should? cuz it does :)
21:14	flaskan	If you only have 1 core, is STM useful then? like i cant hvae more execeutionsppeed right? but i can still have better concurreny
21:15	powr-toc	cooldude127: hehe... was reading the code, not running it :-)
21:15	cooldude127	words cannot express how happy i am having ERC for IRC right next to a clojure slime buffer
21:15	cooldude127	emacs FTW
21:15	julian_morrison	flaskan: threads still contend on a preemptive multitasking OS, even on one core
21:16	danlei	god, making music is hard
21:17	julian_morrison	question for anybody who knows Clojure concurrency well: how would you code reactive behavior?
21:17	julian_morrison	both STM and agents seem to be purely applicative - the best I've come up with is spin-and-poll
21:18	Chouser	julian_morrison: you want a thread to block until some kind of signal?
21:19	rhickey	you can add watchers to agents
21:19	julian_morrison	Chouser: I'm thinking something like a comms protocol that has states and reacts to inputs, errors, etc
21:20	julian_morrison	rhickey: you can?
21:20	rhickey	julian_morrison: add-watch/remove-watch
21:21	cooldude127	woah
21:21	cooldude127	didn't know that was there lol
21:21	rhickey	but for what you are describing, agents are the same as actors, just not switch statements
21:21	rhickey	the functions you run can implement a state machine with the state
21:21	julian_morrison	ah, that must be new, it hasn't made it to the web site
21:22	cooldude127	how up-to-date is the web site?
21:22	Chouser	might refs one day support watchers as well?
21:22	danlei	cooldude127: it's still experimental
21:22	julian_morrison	rhickey: I've been thinking about the agent, actor thing. People keep saying they're similar but they look like duals to me.
21:23	rhickey	julian_morrison: agents are an open protocol and actors are closed
21:23	rhickey	an actor is waiting for a fixed set of inputs
21:23	rhickey	an new function for an agent can be defined and sent at any time
21:24	julian_morrison	one moves data to code, the other moves code to data
21:24	julian_morrison	actors are implicits stateful, even if the state is in tail call parameters
21:25	rhickey	both are stateful
21:25	julian_morrison	and actors can give security gurantees - agents obviously can't
21:25	rhickey	that's right, Clojure doesn't protect against internal malice, but few systems really do or can
21:26	cooldude127	rhickey: that kind of protection is usually restrictive
21:26	julian_morrison	agents are stateful in a strange way. the only state is the reference. they're the most purely FP concurrent system i've ever seen
21:26	rhickey	actors bifurcate the control model into messages and functions, agents use a single control model
21:26	julian_morrison	actors can give strong guarantees, cf the "object capability model"
21:27	rhickey	its the standard dynamic/control tradeoff - Clojure favors dynamic models
21:27	cooldude127	dynamic = yummy :)
21:27	julian_morrison	also, actors don't make assumptions that everyone can see all the RAM
21:28	rhickey	but have the serious limitation of requiring messages to read, which introduces the possibility for deadlock or the necessity of timeouts
21:29	rhickey	a->b tell me something, while b->a tell me something, a waits for b, b for a, deadlock
21:29	rhickey	so actors impose the overhead of a distributed model even in the local case
21:29	rhickey	I decided against that
21:30	rhickey	but yes, agents are a shared memory system
21:30	julian_morrison	I think you could work around that deadlock but it would involve a very strong asynchrony assumption and an effort to never block
21:30	powr-toc	rhickey: are there any good papers on pros/cons of actors which influenced your decision?
21:30	rhickey	powr-toc: just read about Erlang
21:31	rhickey	julian_morrison: timeouts are the norm with actors
21:31	powr-toc	rhickey: hehe, that'd all be pro actor literature then ;-)
21:31	cooldude127	erlang is all actor-ed up
21:31	rhickey	powr-toc: not at all, there ar epapers about deadlocks, lost messages, etc
21:32	powr-toc	cool... I'll have to go and dig em out..
21:32	rhickey	Erlang is a great way to do comm apps, but comm apps are hard
21:32	rhickey	all apps shouldn't be that hard
21:32	powr-toc	true
21:33	julian_morrison	what apps nowadays aren't comm apps
21:34	julian_morrison	even my desktop widgets are often comm apps
21:34	rhickey	parts of apps are comm, but not simple object interactions
21:35	julian_morrison	no, that's true, apps are usually comm on their outside
21:35	rhickey	the vast majority of an app shouldn't work that way, IMO
21:35	julian_morrison	although big apps often are comm on their inside
21:35	powr-toc	rhickey: Have you any plans to better support distributed apps in clojure?
21:35	rhickey	incredibly cumbersome
21:35	rhickey	powr-toc: there will be support for message queues, probably on top of JMS
21:36	powr-toc	cool
21:36	rhickey	julian_morrison: inside, many things are solved by queues
21:37	julian_morrison	rhickey: are there FP queues in Clojure? I know there are non-FP ones in Java
21:38	rhickey	julian_morrison: I don't think queues should be FP - I like j.u.concurrent for workflow
21:39	julian_morrison	rhickey: aside, a request: pretty please, could we have the API doc in PDF?
21:39	rhickey	there is a PersistentQueue in the Clojure lib but not exposed in the API yet
21:39	julian_morrison	no FP in queues? Interesting. Why?
21:40	rhickey	julian_morrison: because you need to pace work, i.e. block
21:41	rhickey	julian_morrison: http://clojure.googlegroups.com/web/manual.pdf
21:42	julian_morrison	rhickey: thanks :-D
21:43	julian_morrison	hmm. I wonder if "functional reactive programming", Haskell style, applies
21:47	julian_morrison	that is, describing blocking semantics as a function of lazily streaming input
21:56	rhickey	julian_morrison: I don't know enough about FRP, but the little I've read about seemed inordinately complex
21:57	rhickey	why simulate time when you have real time?
21:57	blackdog_	are there any examples (apart from rhickey's lisppast) on the new gen-class stuff
21:57	powr-toc	rhickey: one thing erlang supports is safe hot code-swapping, as fn's are def'd is there a safe way to update a function definition in a running system?
21:58	blackdog_	do i need to use import or use to get at it from clojure
21:58	hiredman	I do it all the time with clojurebot, just dump updated functions into the repl
21:58	rhickey	blackdog_: you can just use :gen-class in your ns declaration
21:59	powr-toc	hiredman: yeah, but what would happen if that function was running at the moment you updated?
22:00	rhickey	powr-toc: it doesn't mutate running code, just swaps the fn in the var
22:00	blackdog_	ok, and if i want to generate a new instance in clojure is that (my.ns.) ?
22:01	rhickey	next call sees new code
22:01	julian_morrison	powr-toc: the Erlang way is that you can have two versions, and when the old version tail calls with a package name prefixed, the call goes to the new version and the old version gets unloaded
22:01	rhickey	julian_morrison: yes, Erlang is more sophisticated in this area
22:02	julian_morrison	rhickey: blame the JVM not yet supporting tail calls ;-)
22:02	powr-toc	julian_morrison: yeah, OTP's quite nice in that regard
22:02	rhickey	not the tail calls, the multiversion update
22:03	julian_morrison	as to the simulated time thing earlier, I think that's a Haskellism.
22:03	rhickey	plus it is module granularity, Clojure's is per var
22:03	powr-toc	rhickey: true
22:03	julian_morrison	rhickey: if you had tail calls, you could do it the Erlang way, just tail calling the var
22:05	blackdog_	ah hang on, is the ns version specifically for AOT? I see a gen-class function now too, which is really what I want in this case i think
22:06	Chouser	blackdog_: I don't think you're meant to call gen-class directly.
22:06	rhickey	julian_morrison: a long running agent often works that way, sending the same action to itself, will see updated code
22:07	blackdog_	ah, ok, how do i get hold of a new instance of my class then - feeling dense
22:08	rhickey	julian_morrison: but most Clojure code isn't wait/do/loop as in Erlang. Agents are idle, new actions use new code
22:09	hiredman	clojurebot: new Class(x) is (Class. x)
22:09	clojurebot	You don't have to tell me twice.
22:09	hiredman	hmmm
22:09	hiredman	clojurebot: new is <reply>new Class(x) is (Class. x)
22:09	clojurebot	You don't have to tell me twice.
22:09	rhickey	julian_morrison: I've read Haskell School of Expression, Hudak's book on FRP
22:10	rhickey	As someone who's worked on professional broadcast multimedia systems, I found it pretty irrelevant
22:10	julian_morrison	fair enough
22:11	rhickey	time is the hole in the functional model, as functions don't have time, but real programs do
22:11	julian_morrison	Haskell is often trying to push the envelope of "just how far can we get with one hand tied behind our backs" anyhow
22:12	rhickey	agents and refs model time
22:12	julian_morrison	actors model physics and were designed from it ;-)
22:12	rhickey	I think Haskell is absolutely right to push that agenda and see where it goes, I've learned a lot from it
22:13	rhickey	julian_morrison: I quite disagree about actors - Armstrong is always saying that's the way the world works but it simply isn't
22:13	julian_morrison	rhickey: how so?
22:13	rhickey	we can observe things without their cooperation - not everything is messaging
22:13	julian_morrison	rhickey: you observe something by bouncing a particle off it. particle interactions are local.
22:14	rhickey	I don't bounce a particle off it - a particle bounced off it and hit me
22:14	julian_morrison	even quantum stuff is local if you use the Everett model
22:14	rhickey	no cooperation
22:15	julian_morrison	doesn't matter, same difference. the particle's interaction with you is also local
22:15	rhickey	I think there's all kinds of intention in the actor model not present in physics, but am no physicist
22:16	skrit	are refs the idiomatic way to do something like paul graham's accumulator generator?
22:16	skrit	(defn acc-gen [n] (let [x (ref n)] (fn [y] (dosync (alter x + y)))))
22:16	rhickey	skrit: pgs accumulator generator is a real waste of time
22:17	skrit	even as an exercise?
22:18	rhickey	If I try to bounce a message off an actor that it doesn't understand, it controls what happens
22:19	rhickey	skrit: yeah, think of something cool you'd like your computer to do and make it do that, much better exercise
22:19	julian_morrison	rhickey: true
22:19	skrit	yeah, just coming from a lisp background rather than java, starting off in what I know
22:20	rhickey	skrit: unfortunately some of those exercises don't encourage good habits
22:21	skrit	so you won't recommend things like project euler, etc
22:21	Chouser	skrit: oh, I like project euler
22:21	rhickey	skrit: no, project euler is neat, and lot of Clojure people are doing that
22:22	rhickey	accumulator generator is silly
22:22	Chouser	it doesn't dictate how you solve the problem -- functional solutoins are generally very natural.
22:22	skrit	oh, I agree
22:23	Chouser	I mean functional solutions for PE problems. :-)
22:23	julian_morrison	g'night all
22:37	notallama	yeah. i'm doing pe right now. it's the first time i have tried it. i looked at it before, but when i only knew java, the programming part was rather unpleasant.
22:40	Chouser	notallama: and now?
22:40	blackdog_	Chouser, you have any full example of gen-class usage
22:41	blackdog_	i understand the definition just don't know how to instance one
22:42	notallama	clojure is quite fun to program in. i end up wanting to implement several solutions.
22:47	notallama	scheme is nice to program in too. and i thought it would be painful, but i also kinda like c. (not for project euler type stuff, though. i like the repl too much there)
22:48	Chouser	blackdog_: no, I haven't worked one up yet.
22:48	Chouser	blackdog_: all I've got are rhickey's example and a simple AOT class with just 'main'.
22:49	notallama	i end up using gdb as a repl in c, but it's not really the same.
22:49	blackdog_	yea, i have that
22:49	blackdog_	and understand it, but i don't know how to use it :)
22:49	blackdog_	do i import or use? neither is working for me
22:51	Chouser	blackdog_: I don't know if you can instantiate the class without AOT.
22:51	Chouser	as in, without compiling it first.
22:51	blackdog_	yea, so use compile first
22:52	blackdog_	ok, I'll give that a shot, i guess i was thinking it was a bit like gen-and-load
22:57	Chouser	yeah, I just confirmed --
22:57	Chouser	'require' doesn't create a class from a namespace
22:57	blackdog_	ok
22:57	Chouser	that is, not one named for the namespace
22:58	Chouser	you have to do a separate compile first, though you can then immediately start using it.
22:58	blackdog_	okdok, thanks
23:04	arohner_	Chouser: to clarify, that means that require will load source or .class, but will not compile source?
23:14	Chouser	It looks like 'require' loads and of course compiles in-memory and evaluates the lib, but does not save it to disk and does not appear to create a class named for the namespace.
23:15	arohner_	that sounds like rhickey's standard orthogonal-ness
23:15	Chouser	or, right, if it finds a .class file that's newer, loads and evals that.
23:32	timothypratley	Exception in thread "main" java.lang.NullPointerException (server.clj:0)
23:32	timothypratley	what might be hiding the line number?
23:32	timothypratley	hmmm I'll try to make an example
23:45	notallama	so i was showering, and those accumulator generators crossed my mind. wouldn't that just be a special case of iterate? (not the same thing, but you'd use it for the same thing)
23:48	hiredman	some thing like http://paste.lisp.org/display/70873
23:49	hiredman	(Except diffferent of course)
23:50	hiredman	(f n) -> g, (g e) -> h, (h :nan) = n+e
23:52	hiredman	hah
23:53	hiredman	user=> ((partial (partial (partial + 1) 2) 3))
23:53	hiredman	6
23:57	notallama	ah. i was thinking it was a function that returned a counter. i see what it's supposed to be now, though.
23:57	hiredman	c is a counter
23:58	hiredman	which is the different part, the same part is returning a function whose result is the current state of the calculation