#clojure – 2009-11-02

2009-11-02

01:24	nipra	How can I get "First Line.\nSecond Line." to be printed as two separate lines in REPL?
01:25	wahjava	nipra, (println "First Line.\nSecond Line.") ??
01:27	nipra	wahjava, thanks a lot :-)
01:27	wahjava	you're welcome, nipra .
06:00	gerry`	hello
06:00	ordnungswidrig	hi
06:00	gerry`	in clojure, when to use "_", any docs about it?
06:00	ordnungswidrig	when you don't care about the binding
06:01	gerry`	,(def a [1 2 3])
06:01	clojurebot	DENIED
06:01	gerry`	,(let [a [1 2 3]]
06:01	clojurebot	EOF while reading
06:02	ordnungswidrig	If you define (defn foo [x _] x) foo must be called with 2 args but as you don't care about the second one, name it _
06:02	gerry`	,(let [a [1 2 3]] (case a [1 _ 3] "ok" "oops"))
06:02	clojurebot	java.lang.Exception: Unable to resolve symbol: case in this context
06:02	gerry`	,(doc deftype)
06:02	clojurebot	"clojure.contrib.types/deftype;[[type-tag constructor-name docstring? attr-map?] [type-tag constructor-name docstring? attr-map? constructor] [type-tag constructor-name docstring? attr-map? constructor deconstructor]]; Define a data type by a type tag (a namespace-qualified keyword) and a symbol naming the constructor function. Optionally, a constructor and a deconstructor function can be given as well, the defaults being
06:04	gerry`	case not support "_"?
06:04	hiredman	_ is not special
06:04	opqdonut	_ is just an identifier
06:04	gerry`	and?
06:04	opqdonut	you could use, for instance, "unused" instead of it
06:04	hiredman	,(let [_ 1] _)
06:04	clojurebot	1
06:04	hiredman	you don't have to "support" it
06:05	hiredman	it's just a convention
06:05	gerry`	,[1 _ 2]
06:05	clojurebot	java.lang.Exception: Unable to resolve symbol: _ in this context
06:05	hiredman	,[1 x 2]
06:05	clojurebot	java.lang.Exception: Unable to resolve symbol: x in this context
06:06	gerry`	,(defn hello [_] (println "hello"))
06:06	clojurebot	DENIED
06:09	gerry`	,(let [a (fn [_] (println "hello"))] (a "ok"))
06:09	clojurebot	hello
06:11	gerry`	hiredman: any wild character in clojure just like _ in prolog?
06:11	gerry`	[1 _ 3] could match [1 "ok" 3] [1 "anything 3] etc?
06:12	hiredman	clojure doesn't do pattern matching
06:13	hiredman	there are at least two macros floating around that implement pattern matching, but it is built into the language
06:14	hiredman	er
06:14	hiredman	not built into the language
06:14	gerry`	which?
06:15	hiredman	which macros?
06:15	gerry`	yes
06:15	hiredman	there is one in contrib
06:15	hiredman	,(doc contrib)
06:15	clojurebot	Gabh mo leithscéal?
06:15	hiredman	er
06:15	hiredman	,(doc match)
06:15	clojurebot	"clojure.contrib.types/match;[[value & clauses]]; Given a value and a list of template-expr clauses, evaluate the first expr whose template matches the value. There are four kinds of templates: 1) Lists of the form (tag x1 x2 ...) match instances of types whose constructor has the same form as the list. 2) Quoted lists of the form '(x1 x2 ...) match lists of the same length. 3) Vectors of the form [x1 x2 ...] match vector
06:16	hiredman	~google clojure pattern matching
06:16	clojurebot	First, out of 1560 results is:
06:16	clojurebot	brool » Pattern Matching In Clojure
06:16	clojurebot	http://www.brool.com/index.php/pattern-matching-in-clojure
06:17	gerry`	i think case should support pattern match
06:18	hiredman	I think Kings was an cool show and NBC made a bad movie canceling it
06:18	gerry`	just like "match" in scala, "case" in haskell
06:19	gerry`	hmm
06:21	hiredman	gerry`: http://clojure-log.n01se.net/date/2008-10-09.html#13:32
06:22	gerry`	ok,thx
08:08	megane	chouser: i think shell-out/sh is leaking file handles
08:08	megane	here's the reason http://dlinsin.blogspot.com/2007/02/javas-runtimeexec-openes-too-many-files.html
08:11	lisppaste8	megane pasted "shell-out/sh" at http://paste.lisp.org/display/89677
08:12	patricius_	i'm wondering, could a web server be written in clojure with the same kind of throughput that yaws, the Erlang-webserver, exhibits?
08:12	patricius_	i'm trying to grasp the differences in terms of scheduling processes/threads
08:12	megane	that's my try at fixing sh
08:12	ambient	i wonder how easy it is to understand my project later when most of the stuff is just macroes upon macroes :p
08:13	hiredman	in some sense that is the measure of a macro
08:13	ambient	quess i have to crank up the documentation
08:13	chouser	megane: huh. I could have sworn I was carefully closing all the streams. :-P
08:13	chouser	megane: have you signed the CA?
08:24	ordnungswidrig	ambient: you mean "macros all the way down"? :-) en.wikipedia.org/wiki/Turtles_all_the_way_down
08:25	ambient	well, not all the way. just a lot of macros calling other macros calling other macros
08:29	ambient	it's actually constructing a whole sub-program... :\|
08:29	ambient	defined by given parameters
08:29	ambient	oh wait... i think that's the definition of a macro
08:44	_ato	patricius_: Clojure doesn't have lightweight threads (aka green threads) etc that I assume Erlang's processes are
08:45	_ato	patricius_: but you could certainly write a high-performance web server by using non-blocking sockets, select() and a thread pool
08:49	megane	chouser: CA? what's that
08:49	chouser	Clojure's agents are not entirely unlike green threads
08:50	megane	ah.. contributor agreement.. no i haven't
08:52	_ato	chouser: true, though I assume in Erlang you can spawn a few thousand processes and have all of them block simulataneously on read() cheaply (which is probably implemented under the hood using select). You couldn't do that with agents as you'd use up the thread pool or create a few thousand OS threads (which would be bad)
08:52	chouser	_ato: true
08:53	chouser	welll, true that that's how Clojure behaves and that it would be bad for thousands of sockets. I don't know if it's ok in Erlang or not.
08:53	megane	chouser: you'll have to fix it yourself :P
08:53	chouser	megane: np
08:54	AWizzArd	Although Jetty for example can handle a few thousand threads concurrently.
08:55	AWizzArd	And in the past I think Java had green threads and then switched to OS threads.
08:55	_ato	http://docs.codehaus.org/display/JETTY/Continuations
08:55	_ato	huh
08:55	_ato	interesting
08:56	_ato	it "suspends" a thread by throwing an exception and retries later
08:59	cemerick	is anyone writing web servers anymore? ;-)
09:01	_ato	but yeah, from a performance stand-point select and a thread pool (like what jetty does) is going to be just as good as whatever erlang does, because that's how erlang will be implented underneath. The only advantage with erlang is you don't have to be as explicit with state, you can use the call stack as your state
09:01	ambient	this can't be abstacted with macro-fu?
09:02	_ato	you could probably come up with something good enough, I think you'd need continuations to do it really nicely
09:05	cemerick	heh, if that were the case, apache would've been written in scheme
09:06	cemerick	or lighty, or nginx, or...
09:07	_ato	for most HTTP stuff it doesn't matter as most HTTP is stateless
09:08	cemerick	oh, so we're talking about a seaside-esque thing?
09:08	_ato	yeah
09:09	cemerick	I remember enjoying working with webobjects, which had great transparent session management -- totally resumable, stateless as far as the developer was concerned, etc.
09:09	AWizzArd	Btw, when I want to read from an input stream there is the .available method that tells me how much i can read without blocking. Is there a way to have my thread sleeping for N msecs OR until some more data is available?
09:10	_ato	I have horrid memories of WebObjects, a major app at work is written in it and WO is buggy as hell. But yeah the continuations stuff is neat
09:11	cemerick	That's very surprising to hear. It was rock-solid when I used it.
09:11	_ato	AWizzArd: yes, but it's annoying. http://java.sun.com/j2se/1.4.2/docs/api/java/nio/channels/Selector.html
09:11	_ato	cemerick: could be cause we're running on Solaris
09:11	_ato	actually WO itself is mostly okay, it's mainly the database layer EnterpriseObjects or whatever it is that we had trouble with
09:12	_ato	things like if you loop through a list of EO objects with a java for-each style loop half of the objects are null, where if you do a for (i=0; i<10; i++) {} style thing it works fine
09:12	cemerick	_ato: heh -- that's actually the piece of WO that is most widely acknowledged as being very innovative. Really set the bar w.r.t. ORM.
09:21	_ato	yeah, on paper it's great, but we just ran into lots of implementation problems. Like I said though, we're running on Solaris inside Tomcat which is not really what it's designed for and it's huge (poorly designed) app with a insanely complicated database schema. (I work at a library and boy do libraries love overcomplicated data schemas)
09:25	AWizzArd	_ato: oh :(
09:25	AWizzArd	Can you give one or two short examples of where Tomcat is not doing what it was designed for?
09:27	_ato	AWizzArd: sorry that wasn't clear, I mean WebObjects isn't designed to run in Tomcat on Solaris. It's supposed to run on OS X server... and I don't think it normally runs in a container
09:36	_ato	tomcat is fine
09:36	_ato	well mostly fine, it has some weirdnesses but mostly they're due to JVM limitations
09:44	cemerick	Tomcat is pretty darn solid. Holds its own against just about any other servlet container for 95% of use cases.
09:51	cemerick	anyone pay github for private git hosting, and want to share experiences?
09:56	AWizzArd	What is a good way to follow the flow of (or debugging support for) my app? contrib.logging?
09:56	chouser	I think there is at least once "trace" lib around
09:58	raek	has there been any effort to make DWIM-like things for clojure?
09:59	raek	and another question: are the original s-expressions kept when code is compiled?
10:02	chouser	raek: 1) I don't know what you mean. 2) no.
10:08	ambient	i have a java callback function that i need to create with clojure. how do i enforce the types that are used to call that function?
10:08	ambient	like "int javafunc(float[] foo, int bar)"
10:09	ambient	(fn [#^floats foo ??? bar] 0) is my best idea so far
10:10	cemerick	ambient: type hints do not enforce types, they provide a way to avoid reflection
10:11	ambient	ok
10:11	cemerick	if you need to provide a typed API to some Java code, you should proxy or gen-class an interface
10:24	AWizzArd	Who of you used clojure.contrib.logging? I would like to know where the log output is landing, and how I can turn logging of.
10:48	AWizzArd	Does contrib have a without-exception macro, which returns nil in case of an exception? (try (some-operations-here) (catch Exception e nil))
10:53	dakrone	AWizzArd: (defmacro trycatch [f] `(try ~f (catch Exception e#))) ?
11:10	stuartsierra	,(binding [+ -] (+ 1 1))
11:10	clojurebot	2
11:10	stuartsierra	Why doesn't that work?
11:11	rhickey	+ has inlining
11:11	stuartsierra	ah, ok
11:11	stuartsierra	,(binding [mod -] (mod 1 1))
11:11	clojurebot	0
11:12	danlarkin	bad example :)
11:22	arsatiki	I just finished Halloway's book. Time to pass it around
11:23	blackdog_	stuartsierra, I'm having issues with http.agent, it doesn't seem like it's blocking, on a simple get, with one request relying on another to finish
11:23	AWizzArd	blackdog_: you mean (string (http-agent ...)) yes?
11:23	blackdog_	yes
11:23	AWizzArd	I noticed the same phenomenon.
11:23	blackdog_	i've just replaced httpagent with apache httpclient and my code and server are both good
11:24	blackdog_	ok, as long as I'm not alone, I'll send some details to the list later
11:24	AWizzArd	And that's really strange, because string under the hood calls result which uses await to finish.
11:24	AWizzArd	But it is important that there must be some delay until await gets called.
11:24	blackdog_	i get a connection not closed error
11:24	AWizzArd	yes
11:25	blackdog_	when it tries to set the options for the next connection
11:25	AWizzArd	but if you (let [a (http-agent ...)] (Thread/sleep 1000) (string a)) then it would work
11:25	blackdog_	like it didn't disconnect,
11:25	AWizzArd	or even better use (await-for a 1000) instead of Thread/sleep
11:25	blackdog_	yes, if I wait at the repl and reissue, it's all good
11:26	blackdog_	that's scalable ;)
11:26	AWizzArd	Maybe stuartsierra has an idea why this explicit await-for is needed.
11:29	churib	is there a fn like "some" which returns the first element for which pred is true?
11:30	stuartsierra	This was reported on the list; there's a patch, working on it now
11:30	rhickey	,(first (filter odd? (range 1000000000000)))
11:30	clojurebot	java.lang.ExceptionInInitializerError
11:31	blackdog_	stuartsierra, ok, thanks
11:31	rhickey	,(first (filter odd? (range 1000000)))
11:31	clojurebot	1
11:31	churib	thanks!
11:31	rhickey	churib: leverages the fact that filter is lazy
11:32	churib	yeah, easy solution - i was to blind to see it :)
11:38	spuz	rhickey: do I need to sign the CA to raise issues in clojure or clojure contrib?
11:39	rhickey	spuz: no, you can use the Support tab there
11:42	spuz	ah not sure how i missed that
11:43	stuartsierra	blackdog_: should be fixed on master now
11:47	AWizzArd	stuartsierra: sounds good, thx
11:48	spuz	stuartsierra: you applied the patch?
11:48	spuz	(this is alex by the way)
11:48	rhickey	stuartsierra: thanks for fix to http://www.assembla.com/spaces/clojure-contrib/tickets/41
11:51	stuartsierra	welcome
11:51	stuartsierra	spuz: no, I fixed it a different way
11:52	spuz	cool
11:52	spuz	You got a good number of tickets closed today :)
11:53	stuartsierra	yeah, working my way through
11:55	stuartsierra	rhickey: when a core patch is ready, should I assign it to you or just mark it "Ready to Test"?
11:56	rhickey	stuartsierra: just mark as ready to test, thanks
12:24	Kjellski	Hi there...
12:29	replaca	Kjellski: hi
12:29	Kjellski	replaca : hiho =)
12:30	Kjellski	Anyone got the enclujure shortcut for switching to repl and back in mind?
12:32	Kjellski	,(doc loop)
12:32	clojurebot	"([bindings & body]); Evaluates the exprs in a lexical context in which the symbols in the binding-forms are bound to their respective init-exprs or parts therein. Acts as a recur target."
12:37	cemerick	Kjellski: Cmd-T on mac, probably Alt-T on windows.
12:39	Kjellski	cemerick : thanks!
12:40	Kjellski	cemerick : it was C-t but the hint did the trick =)
12:40	cemerick	The mapping between Cmd and Alt/Ctrl is tough to nail down in general.
12:43	Kjellski	Sure it is... do you have a Enclojure Cheat Sheet? I´m actually switching from emacs and on the homepage they just wrote look at the context menus...
12:43	blackdog_	stuartsierra, thanks, http-agent working as advertised
12:45	cemerick	Kjellski: if you open the netbeans preferences dialog, and go into the keybindings section, you can look at just the clojure bindings
12:46	Kjellski	cemerick, something I could have done... sorry, a bit frightened from the emacs options "menu" ...
12:46	cemerick	Kjellski: you're in a much more hospitable land now :-)
12:48	Kjellski	cemerick : laughing
12:48	cemerick	I'm surprised there's no one around to yell at me for my emacs trolling. :-P
12:49	Kjellski	g thought so too...
12:50	Kjellski	How can I get the key-value pairs out of a map?
12:50	cemerick	,(seq {:a :b :c 5})
12:50	clojurebot	([:a :b] [:c 5])
12:50	Kjellski	Outch... thanks again...
12:52	replaca	but maps can be used directly as seqs in most cases, so you usually don't need the (seq ...)
12:52	Kjellski	cemerick: and anotherone for you, how can I force enclojure to just indent when it´s neccessary? like tabbing in a new line will not add tabs when it is already indented the right way?
12:53	tomoj	replaca: what is an example of a case where they can't?
12:53	cemerick	right, most forms wrap inputs in an implicit seq
12:54	cemerick	Kjellski: hitting return will put the new line in the right place. 'Tab' is not 'reformat' like it is in emacs. Try Ctrl-R.
12:54	Kjellski	cemerick : now its M-r ... weird... ^^
12:55	cemerick	See what I mean? :-)
12:57	Kjellski	cemerick : yes, pretty annoying
12:58	cemerick	it's worth filing a bug over. In the meantime, you can just rebind things to what you want.
12:59	Kjellski	cemerick : okay, so I´ll do that if it comes up again...
13:01	Kjellski	cemerick: Actually rebinding Reindent Clojure Code to TAB works just fine =)
13:01	cemerick	ha. I never tried it. I've almost forgotten that that key is there.
13:01	Kjellski	cemerick : exactly what I wanted.
13:02	Kjellski	cemerick : it just sais "not recommended"... but it´s heaven... =)
13:04	replaca	tomoj: I can't think of one
13:05	chouser	,(nil? (seq {}))
13:05	clojurebot	true
13:05	chouser	,(nil? {})
13:05	clojurebot	false
13:27	replaca	chouser always knows the subtlety!
13:27	replaca	chouser: I'm really looking forward to your book - I was happy to hear you're doing it
13:28	Kjellski	replaca : how is it called?
13:29	chouser	replaca: thanks, that's great to hear!
13:30	replaca	chouser: remind Kjellski of the title. It's in my mind as "Idiomatic Clojure"
13:30	replaca	which translates to "Chouser" in my dictionary
13:31	chouser	that's the working title, but it has it's detractors so we'll see. :-)
13:31	Kjellski	replaca : laughing
13:31	cemerick	a clojure book by chouser? Where do I buy? :-D
13:31	Kjellski	./signed
13:31	chouser	aw, you guys. It's actually Fogus' book, I'm just helping.
13:31	Kjellski	Can we see drafts or is it closed till release?
13:32	cemerick	chouser: First I've heard of it. Is there an announcement somewhere? (It's been a very busy morning.)
13:32	cemerick	uh, day.
13:32	chouser	Nobody's even supposed to know about it yet, but I guess it leaked. :-)
13:33	Kjellski	chouser : somewhere, somehow...
13:33	chouser	There will be a MEAP which is what Manning calls their on-line pre-release PDF thing
13:33	chouser	but we're not quite there yet. Once there's a page for it, we'll make sure everyone knows. -)
13:33	chouser	:-)
13:33	Kjellski	chouser: I´m very interested... can I just subscribe somewhere?
13:34	Kjellski	chouser : okay.
13:34	chouser	either fogus or my twitter, or either of our blogs I imagine.
13:34	chouser	...for any announcements.
13:35	cemerick	chouser: well, at least you know there's a pile of interest. I'm sure everyone here will blog about it. It's about time someone banked some coin for irc time. :-)
13:35	chouser	heh. Right, I've been doing research for it right here for the last almost two years.
13:37	fogus_	My ears are burning ;)
13:37	cemerick	whoa, #clojure has a strong echo
13:37	cemerick	fogus_: congrats :-)
13:38	fogus_	Thanks sir
13:38	Kjellski	laughing that´s what came in my mind... nice timing fogus...
13:39	fogus_	I was warned by chouser that I was getting slammed in here. ;)
13:40	cemerick	chouser: quick, trunc those logs, eh?
13:40	chouser	heh
13:40	hamza	hey guys, i have a vector of bytes [115 116 114] how can i build a string out of this? convert each byte to char then append?
13:41	chouser	,(apply str (map char [115 116 114]))
13:41	clojurebot	"str"
13:42	chouser	,(->> [115 116 114] (map char) (apply str))
13:42	clojurebot	"str"
13:42	leafw	what is ->> ?
13:42	leafw	,(doc ->>)
13:42	clojurebot	"([x form] [x form & more]); Threads the expr through the forms. Inserts x as the last item in the first form, making a list of it if it is not a list already. If there are more forms, inserts the first form as the last item in second form, etc."
13:42	chouser	just what I showed there -- allows rearranging a set of nested forms.
13:44	hamza	thx, that worked which namespace is ->> defined ?
13:44	tomoj	clojure.core
13:45	hamza	thank you, i guess my build is out of date..
13:45	leafw	would be nice to have a fn like 'doc' or 'class' that lists the complete namespace and source package of a fn.
13:45	Kjellski	chouser can I ask for your blog?
13:46	chouser	Kjellski: http://blog.n01se.net/ -- I actually share it with some friends, but everything they post is at least as interesting as what I do. :-)
13:50	Kjellski	chouser : thanks, that´s in my reader now... =)
13:50	chouser	Kjellski: thanks! No worries -- you won't be overwhelmed with posts...
13:50	chouser	What little effort I put into blogging now goes into the book instead. :-P
13:51	chouser	plus some, I should say.
13:51	Kjellski	Actually I can see a ")); at the very bottom of the blog... just my first feedback before reading ... ;)
13:52	Kjellski	chouser : Okay, that´s nice... I´ll wait for it...
13:57	Kjellski	chouser : can you see that too?
13:57	tomoj	I can
13:57	chouser	yeah, thanks.
14:00	Kjellski	Okay, nevermind... first thought that was a bit hard as a first feedback ^^
14:01	chouser	no, not at all. working on it.
14:01	chouser	but I hardly understand this blog software. so difficult. so much PHP
14:02	chouser	huh. I think I broke it.
14:03	Kjellski	I think so too...
14:04	Kjellski	So, sorry about killing you blog with my suggestions... but I have to leave... happy php'ing ... ;)
14:04	chouser	heh. ok, bye.
14:04	Kjellski	bye
14:15	technomancy	chouser: just make sure the book doesn't end up with the title "Programming Clojure" =)
14:15	chouser	technomancy: heh. got it.
14:17	fogus_	technomancy: Is that one taken? ;)
14:17	Chousuke	I had to code some Qt today in C++ and the machine I coded on was kind of slow so each compilation took at least a minute ;/
14:17	technomancy	fogus_: we don't want Clojure to be seen as just a copycat of Scala you know...
14:17	Chousuke	made me wish C++ were a dynamic language.
14:18	hiredman	Chousuke: that's not bad for C++
14:18	Chousuke	hiredman: mind you, it's not a big application.
14:18	fogus_	technomancy: I guess that doesn't bode well for my planned chapter "Adding a Type System to Clojure"
14:18	hiredman	while I was working on my reader I routinely rebuilt clojure over and over, which when I was on my netbook sometimes took five minutes
14:19	fogus_	(just kidding BTW)
14:19	Chousuke	it wasn't really fun to have to wait for a minute after you make some quick ten second edit and check that it works ;P
14:20	cemerick	developing on a netbook? ouch.
14:20	chouser	"How to work around Clojure deficiencies: immutability and dynamic typing"
14:20	hiredman	D:
14:20	hiredman	deficiencies?
14:20	chouser	that's chapter 2!
14:21	chouser	it includes macros that let you have mutable locals: mlet
14:21	clojurebot	Holy Crap.
14:21	hiredman	I use my netbook a lot
14:22	tomoj	I develop on my netbook almost all of the time
14:22	Chousuke	chouser: are you really going to call them deficiencies? :P
14:23	hiredman	it's just so easy, the computer is so small and it's right there, and you're just going to do some exploritory coding 500 lines of code later huh, I guess I'm done
14:24	chouser	Chapter 4 is entirely devoted to a reader patch that allows you to use C++ syntax to generate Clojure so you never have to look at parens.
14:25	hiredman	http://gist.github.com/223246 <-- :P
14:25	tomoj	I can't bring my imac out onto the patio while I smoke
14:26	Chousuke	hiredman: argh.
14:27	chouser	ok, just so it's clear I was kidding about every bit of book content info above.
14:28	hiredman	cc is a macro that, at macro expansion time, generates a .c file and compiles it, then returns a fn that when executed executes the native binary
14:31	hiredman	sort of a prototype, ideally you'd want to generate a shared library, not an executable, and have the macro return a fn that calls functions from the shared lib via jni or jna or something
14:47	chouser	for anyone that cares, my blog is un-broken again. :-P
15:02	djork	http://www.jwz.org/doc/java.html <-- Clojure sure goes a long way towards addressing these complaints
15:03	hiredman	I finished coders at work this morning
15:04	gyom	nice
15:04	hiredman	djork: it's also at least ten years old
15:04	gyom	hiredman : they all rant against C++, or almost all of them
15:04	hiredman	gyom: and the last few against C
15:04	gyom	hiredman : but I'm halfway through
15:05	djork	its ten years old but Java hasn't fixed much of it in that time
15:05	gyom	I read an older book, something like "Programmers at work", and I thought the interviewer was doing a better job
15:05	hiredman	djork: generally there are two classes of complaints against java, jvm issues and The Java™ Programing Language
15:06	djork	the JVM is much much better, that's for sure
15:06	gyom	in Coders at work it seems like the interviewer jumps back to the literate programming thing when it's not that relevant
15:07	hiredman	gyom: well it's interesting that taocp is mentioned in every interview, but no one uses Knuth's literate style
15:07	chouser	djork: clojure also doubles-down on some of those (like interfaces)
15:07	djork	yeah
15:08	gyom	hiredman : Yes, they all have a copy of taocp, all they all discuss whether math is relevant or not.
15:09	hiredman	you need a certain bit of math just to be able to use taocp as a reference
15:10	gyom	sure, you need math to understand why log(n) is O(n^{1+epsilon}), at least
15:10	gyom	hum
15:10	gyom	n log n, that is
15:11	hiredman	the bibliography of coders at work shall be mined for material
15:11	hiredman	there were some nice quotes here and there too
15:11	hiredman	~programmer
15:11	clojurebot	"There has to be something a little wrong with you for you to be a really good programmer." -- L Peter Deutsch
15:13	hiredman	there is another one about programmers being the worst optimizers
15:52	tmountain	one more reason to love clojure
15:54	chouser	I live by doc/source/show and occasionally javadoc
15:55	hiredman	javadoc javadoc javadoc
15:55	froog	has there been any discussion about docstring format, something like doclet?
15:56	hiredman	javadocs are so great
15:59	hiredman	I'm not
16:00	chouser	hm... still sounds like sarcasm. :-)
16:00	hiredman	~hiredman
16:00	clojurebot	hiredman is an evil genius.
16:07	cemerick	one of these days, I'm going to have to bite the bullet and put together a javadoc generator for clojure projects.
16:08	hiredman	huge list of IFn's that take Objects
16:09	cemerick	having defclass around should make it somewhat easier to do, actually
16:11	technomancy	I'd have a lot happier time with javadoc if it didn't use frames for everything
16:12	technomancy	makes mouseless browsing trickier
16:12	hiredman	shrug
16:12	technomancy	but I find that usually the slime inspector is a much more convenient alternative ... need to get a blog post up about that.
16:12	tomoj	does the slime inspector show javadoc comments?
16:13	froog	technomancy: that's more a result of how the javadoc was generated, isn't it?
16:13	technomancy	tomoj: no, but usually javadoc comments are stuff like getFoos: gets all the foos from the object.
16:13	hiredman	hyperlinked autogenerated docs are genius
16:13	technomancy	so you're usually not missing much
16:13	tomoj	yeah
16:13	hiredman	http://www.igniterealtime.org/builds/smack/docs/latest/javadoc/
16:13	technomancy	there are exceptions, but that's the common case
16:14	technomancy	froog: there are nicer templates, but they are not often used. I guess I could generate my own.
16:15	hiredman	clojuredoc should generate some kind of wikifiable information
16:15	froog	technomancy: I meant that you can generate the doc with another doclet, like texidoclet, if it was up-to-date
16:15	froog	then you could generate info files from there
16:16	technomancy	froog: yeah, having a copy of the source checkout can be a hassle at times. but if you have it and the docs are good, that's probably the way to go.
16:16	chouser	I use 'show' until I need a more meaningful javadoc comment like "make sure you always call foo before bar"
16:16	technomancy	yeah... slime inspector is like a hyperlinked version of repl-utils/show
16:16	froog	technomancy: true, you need the source for that
17:06	ordnungswidrig	hi all
17:07	djork	hi!
17:07	djork	my friend wants to start learning programming tonight
17:07	djork	I want to teach him Clojure
17:07	djork	but...
17:07	djork	the Java part might be a problem
17:07	ordnungswidrig	djork: could be a magic night then
17:08	hiredman	teach him lua by writing a lisp interpreter in lua
17:08	ordnungswidrig	djork: or start with the lambda calculus. a solid theoretical founding cannot be wrong ;-)
17:08	ordnungswidrig	djork: so why do you think the java part is a problem?
17:09	djork	Lua might be good
17:09	djork	Java is troubling because he has no OO experience
17:09	djork	no programming at all in fact, just web markup
17:10	jasapp	what's wrong with clojure?
17:10	ordnungswidrig	djork: I see, clojures stack traces must be frightning to him them
17:11	jasapp	scheme, drscheme in particular, is great for that sort of thing
17:11	djork	yeah the stack traces might be rough
17:13	djork	DrScheme could be good
17:13	ordnungswidrig	btw. is there a plan to improve the stack traces anyway?
17:13	hiredman	ordnungswidrig: maybe after or as part of cinc
17:13	ordnungswidrig	cinc?
17:13	hiredman	clojure in clojure
17:14	ordnungswidrig	turtles all the way down, again :-)
17:14	hiredman	lua is a neat little language, a simple lisp would be, maybe a few hundred lines
17:15	ordnungswidrig	slime masters available? how to I "slimify" a buffer after connecting to a running swank using slime-connect?
17:15	technomancy	M-x slime-mode
17:15	technomancy	but that should happen automatically for you
17:16	technomancy	you should launch slime using M-x slime rather than M-x slime-connect btw
17:16	ordnungswidrig	technomancy: I start swank by maven
17:16	ordnungswidrig	technomancy: To avoid all kinds of classpath issues
17:17	technomancy	oh gotcha. it still should activate slime-mode for you though. wonder what's going on.
17:17	ordnungswidrig	M-x slime-mode enables slime[clojure] but the keybindings are missing...
17:17	ordnungswidrig	technomancy: maybe it's a slime-swank-emacs-version isssue. using slime 2009-05-17
17:18	ordnungswidrig	should I switch to the epla branch?
17:20	technomancy	actually the "maven" branch is the current release candidate
17:21	technomancy	check the swank-clojure mailing list, I haven't updated the docs in the project yet.
17:21	ordnungswidrig	huh, I don't see this one on github
17:25	djork	oh hey, nice clojure cheatsheet for http://cheat.errtheblog.com/
17:26	djork	hmm, not the best ever
17:31	ordnungswidrig	hmm, string contains in clojure? Only via java or is there an idiomatic way?
17:35	tomoj	I think there are generally not clojure wrappers for things that are very easy to do with java
17:36	ordnungswidrig	which makes sense in a way
17:38	dnolen	,(re-find #"e" "Hello")
17:38	clojurebot	"e"
17:38	dnolen	ordnungswidri ^
17:38	ordnungswidrig	g
17:41	technomancy	they would make such great predicates
17:42	ordnungswidrig	technomancy: can't you macro it?
17:42	dnolen	ordnungwidri: technomancy means something like (#"e" "Hello") -> "e", can't macro that.
17:43	technomancy	in a turing-tarpit kind of sense such a thing might be technically possible, but not practically.
17:43	hiredman	technomancy: fnparse :D
17:43	spuz	How does one retrieve input from the stdin or repl?
17:44	hiredman	in is boundg to System.in by default
17:47	hiredman	,(hiredman.clojurebot.factoids/predicate-style-definition {:remainder "foos \| are \| great"})
17:47	clojurebot	hiredman: Pardon?
17:47	hiredman	clojurebot: jerk
17:47	clojurebot	excusez-moi
17:48	hiredman	,(predicate-style-definition {:remainder "foos \| are \| great"})
17:48	clojurebot	[{:subject "foos", :object "great", :predicate "are"} {:remainder nil}]
17:48	hiredman	,^(first (predicate-style-definition {:remainder "foos \| are \| great"}))
17:48	clojurebot	{:type :predicate-style-definition}
17:50	hiredman	clojurebot: foos \| are \| great
17:50	clojurebot	c'est bon!
17:50	hiredman	clojurebot: foos?
17:50	clojurebot	foos are great
17:51	hiredman	clojurebot: forget foos \| are \| great
17:51	clojurebot	I forgot that foos are great
17:52	ordnungswidrig	hiredman: what's that goog for? Teachning clojurebot?
17:52	ordnungswidrig	s/goog/good/
17:52	hiredman	clojurebot's factoid stuff uses fnparse for parsing
17:52	ordnungswidrig	me is not expected to understand fnparse, right?
17:53	hiredman	ordnungswidrig: clojurebot by default assumes "is" as the predicate
17:53	hiredman	but using that style with the predicate seperated out by the bars you can use arbitrary predicates for factoids
17:54	ordnungswidrig	ah, I see.
17:54	hiredman	clojurebot: I \| can \| dance
17:54	clojurebot	Ok.
17:54	hiredman	clojurebot: I?
17:54	clojurebot	I can dance
17:54	hiredman	clojurebot: forget I \| can \| dance
17:54	clojurebot	I forgot that I can dance
17:54	ordnungswidrig	something different. How can I use functions that will be declared later?
17:54	hiredman	declare
17:55	ordnungswidrig	hiredman: hmm, some things are just too obvious
17:55	spuz	hiredman: This appears to work, but do you know if there's a pre-baked function in clojure or clojure contrib that does the same? (defn prompt [msg] (println msg)(second (read-lines in)))
18:07	ordnungswidrig	http://clojure.pastebin.com/m648ea526
18:07	ordnungswidrig	how can I simplify this one?
18:08	ordnungswidrig	basically I'm passing a context through a serieas of function applications
18:09	hiredman	->
18:10	hiredman	,(1 (+ 2) (* 4))
18:10	clojurebot	java.lang.ClassCastException: java.lang.Integer cannot be cast to clojure.lang.IFn
18:10	hiredman	grrr
18:10	hiredman	stupid inlining
18:10	hiredman	,(1 (#'+ 2) (#'* 4))
18:10	clojurebot	java.lang.ClassCastException: java.lang.Integer cannot be cast to clojure.lang.IFn
18:10	hiredman	oh
18:10	hiredman	mea culpa
18:10	hiredman	,(-> 1 (+ 2) (* 4))
18:10	clojurebot	12
18:11	ordnungswidrig	hiredman: no with destructurizing?
18:11	hiredman	hmmm
18:11	hiredman	yeah
18:12	ordnungswidrig	cries for a monad, I think.
18:13	hiredman	(-> ctx do-foo ((juxt first (comp do-bar second)))
18:13	hiredman	etc etc :P
18:14	ordnungswidrig	hiredman: nice. event point-free
18:14	hiredman	pointless :P
18:15	ordnungswidrig	yes :-) clojure is acutally often point-free. I wonder it's because of the style in #clojure or if the language encourages a point-free style.
18:16	The-Kenny	Because point-free = good :)
18:16	ordnungswidrig	The-Kenny: up to a limit
18:17	The-Kenny	ordnungswidrig: Of course.
18:17	ordnungswidrig	I remember really scary pint-free expression in #haskell
18:17	ordnungswidrig	the flip-apply-flip-flip-apply-of-death
18:18	The-Kenny	haha :D
18:18	ordnungswidrig	more a solution to rubic's cube than a haskell function
18:18	hiredman	oh man
18:19	ordnungswidrig	where, hmm, the haskell folks love algebra. so this seems all reasonable.
18:21	hiredman	,((partial (comp seq reduce) (comp (partial apply conj) (juxt first (comp (partial + 1) second)) list) []) (range 10))
18:21	clojurebot	(1 2 3 4 5 6 7 8 9 10)
18:22	ordnungswidrig	hiredman: is this id on seqs or a general identify?
18:22	ordnungswidrig	hiredman: or on seqs of ints?
18:23	hiredman	it's (partial map (partial + 1))
18:23	hiredman	but strict using reduce
18:24	ordnungswidrig	I see. This wasn't an identity at all.
18:24	hiredman	hmmm
18:24	ordnungswidrig	need to sleep soon :)
18:24	ordnungswidrig	,(range 10)
18:24	clojurebot	(0 1 2 3 4 5 6 7 8 9)
18:24	hiredman	I should pull the mapped fn out to be the second arg to make it general
18:29	ordnungswidrig	Is wraping an sexp with an (do (println (str "xxxx")) sexp) idiomatic for debug printing?
18:29	ordnungswidrig	Or is there a better way?
18:30	hiredman	(doto something prn)
18:30	hiredman	but sure that works
18:30	ordnungswidrig	hiredman: this will print the result of something?
18:31	hiredman	yes
18:31	hiredman	and return something
18:31	jhawk28	hiredman: does clojurebot have a limit on the output?
18:31	hiredman	evaluated to
18:31	hiredman	yes
18:31	hiredman	I always feel dirty when I saw "return"
18:31	Chousuke	ordnungswidrig: it would be more idiomatic to use a debug macro I think :)
18:31	ordnungswidrig	it like ? (let [x something] (do (println x) x)
18:32	hiredman	ordnungswidrig: yes, but with prn instead of println
18:32	ordnungswidrig	Chousuke: a reader macro? Like !(something) will evaluate to (doto something prn)
18:32	tomoj	I always feel dirty when I see "prn"
18:33	hiredman	say
18:34	ordnungswidrig	say what?
18:34	hiredman	correcting my earlier statement about return
18:35	hiredman	say return not saw return
18:36	ordnungswidrig	hiredman: oh dear, but that was a late one. Event regex wouldn't helped out and I don't know, if sed expressesions are commonly well understood on IRC.
18:36	ordnungswidrig	s/Event/even/
18:37	hiredman	I see regexs on irc everywhere
18:38	hiredman	the other day I saw someone correct themselves with a regex that used back references
18:38	jasapp	that's kind of disturbing
18:38	technomancy	I'm still waiting for a client that can automatically DTRT when it sees someone type things like s/foo/bar/
18:40	hiredman	http://luaforge.net/docman/view.php/83/95/ANoFrillsIntroToLua5VMInstructions.pdf <-- nice
18:44	chouser	technomancy: wave will come first
18:44	chouser	^ random expression of hope disguised as an unlikely prediction
18:44	hiredman	hmmm
18:48	jasapp	does clojurebot have a way to refer to someone's last comment?
18:48	hiredman	~seen jasapp
18:48	clojurebot	jasapp was last seen in #clojure, 0 minutes ago saying: does clojurebot have a way to refer to someone's last comment?
18:49	jasapp	ahh, interesting
18:50	jasapp	is there a way to call seen from clojurebot's clojure evaluator?
18:51	hiredman	possibly
18:52	hiredman	it would be some work because clojurebot tries to discourage digging around in its own internals from the sandbox
18:52	jasapp	it'd be kind of cool to feed him/her a regular expression and run it over someone's last comment
18:52	jasapp	but it'd also be a big waste of time, too
18:53	hiredman	I suspect it would end up like clojurebot's tinyurl plugin
18:53	The-Kenny	I think something like this would be cooler in a client, not a bot.
18:53	ordnungswidrig	hiredman: I was the one with the backreference
18:53	jasapp	true
18:53	The-Kenny	Personally, I would like to see a irssi plugin :)
18:53	ordnungswidrig	sounds like a no-brainer for erc
18:53	The-Kenny	s/ a / an /
18:55	arbscht	you can probably bend /lastlog in irssi to do that
18:55	ordnungswidrig	it's 01:00am local time which means bed time. moahn
18:56	ordnungswidrig	cu all
18:56	The-Kenny	It's not 01:00 am here, it's 00:57 am :D
19:39	technomancy	drewr: I'm looking at your use of swank in clot; what's the purpose of wrapping start-server in that repl call with the stop atom like you did?
21:08	weissj	i'm trying out some project euler problems, one is to return the 10001st prime. my strategy is to have a primes function return a lazy seq of primes. and a prime? function that iterates over previous primes and divides the current candidate by that list.
21:08	weissj	how can i make sure the list of already-calculated primes doesn't get recalculated each time
21:09	weissj	ie, each call to primes accesses the same list
21:11	_ato__	(def primes-seq (primes)), then just use prime-seq instead of calling your primes function each time?
21:11	_ato__	or use memoize on primes
21:13	_ato__	weissj: note there's a clojure.contrib.lazy-seq/primes but I guess you want to solve it yourself :)
21:13	weissj	_ato__: yeah :)
21:15	weissj	would be a bit too easy to use that: (nth primes 10001)
21:28	lisppaste8	jweiss pasted "untitled" at http://paste.lisp.org/display/89704
21:28	weissj	can someone tell me what's wrong with this ^
21:29	weissj	i get: java.lang.RuntimeException: java.lang.ClassCastException: clojure.core$num__5233 cannot be cast to java.lang.Number (NO_SOURCE_FILE:0)
21:29	weissj	on the line that starts with (take
21:31	weissj	nevermind - used "num" instead of "mynum"
21:41	weissj	anyone know why this happens?
21:41	weissj	(take 1 (lazy-seq (conj (primes) 2)))
21:41	weissj	java.lang.StackOverflowError
21:41	weissj	i wrote the primes function which obviously has infinite recursion problems, but why does it even get called? i only want 1 item in the seq, and that should be the 2 i conj'd on there first
21:43	chouser	I think you mean (lazy-seq (cons 2 (primes)))
21:44	chouser	what you have is a bit interesting, though.
21:46	chouser	,(take 1 (lazy-seq (cons 1 (lazy-seq (prn :hi) '(2)))))
21:46	clojurebot	(1)
21:46	chouser	,(take 1 (lazy-seq (conj (lazy-seq (prn :hi) '(2)) 1)))
21:46	clojurebot	(1)
21:46	chouser	hm, clojurebot doesn't show that :hi gets printed on the second but not the first
21:48	chouser	,(take 1 (lazy-seq (conj (lazy-seq (prn :a) (cons 2 (lazy-seq (prn :b) '(3)))) 1)))
21:48	clojurebot	(1)
21:57	chouser	and that one prints :a but not :b
21:58	chouser	conj on a lazy seq forces one extra step
22:15	qed	hello all
22:21	solussd	is there a easier way to access something in a vector of vectors? e.g. easier than this?: (def grid [[1 2 3] [4 5 6]]) ((grid 1) 2)
22:30	chouser	,(get-in [[1 2 3] [4 5 6]] [1 2])
22:30	clojurebot	6
22:30	chouser	solussd: ^^^
22:30	solussd	excellent.
22:47	emit	sessions in compojure, where exactly do I use the decorate with-session... by itself? inside defroutes?
22:57	emit	ok to answer my question I can just decorate the route itself...
22:57	tomoj	I would think you would decorate the handler
23:09	saml	hey, I do C-c C-d d to see document of symbol.. and C-x o, q to kill the document buffer. can i kill it faster?
23:09	saml	in Clojure Box
23:19	hiredman	qed: well, at least you get all the batteries that way
23:20	hiredman	<3 XeLaTeX
23:20	_ato	saml: hmm.. for me (not using Clojure Box just my own emacs) C-c C-d d makes the doc buffer focusued, so I just press q.
23:21	saml	_ato, oh i see. weird
23:21	hiredman	clojurebot: hiredman \| <3 \| XeLaTeX
23:21	clojurebot	Ok.
23:22	hiredman	clojurebot: hiredman?
23:22	clojurebot	hiredman <3 XeLaTeX
23:22	_ato	saml: Otherwise you could just leave the buffer open but hide it (C-x 1) it'll get reused next time you C-c C-d d, so you don't have to worry about it make hundreds of them
23:23	saml	_ato, yah but wouldn't it leave hundreds of buffers?
23:24	_ato	nah, it'll just reuse the same one
23:24	_ato	at least, again, that's what it does for me
23:27	saml	_ato, ah thanks. kinda hard to see what's going on for a noob like me :P
23:29	_ato	yeah, I'm not too good with emacs either. A real emacs guy would either know a key combo for kill other window or would have some 10 keypress way of defining one and adding it to your .emacs :P
23:31	_ato	I know the first steps: you could define a keyboard macro with C-x ( C-x o q C-x ) and then name it with M-x name-last-kbd-macro, but I'm not sure how to then bind that to a short keystroke
23:32	j3ff	is there a built-in function that returns the max value in a sequence?
23:32	tomoj	well
23:32	_ato	j3ff: yes, funnily enough it's called "max" ;)
23:33	tomoj	(apply max the-seq)
23:33	samUL	_ato, ah thanks
23:33	j3ff	thanks
23:33	tomoj	not sure how well it scales to very large seq
23:33	tomoj	s
23:33	tomoj	perhaps reduce max would perform better
23:34	_ato	,(time (apply max (range 1000000)))
23:34	clojurebot	999999
23:34	clojurebot	"Elapsed time: 545.892 msecs"
23:34	_ato	,(time (reduce max (range 1000000)))
23:34	clojurebot	999999
23:34	clojurebot	"Elapsed time: 239.206 msecs"
23:35	j3ff	interesting
23:35	_ato	,(time (apply max (range 1000000)))
23:35	clojurebot	999999
23:35	clojurebot	"Elapsed time: 403.153 msecs"
23:35	j3ff	one more question, is there another function to return said index of the max? :)
23:35	_ato	hmm
23:35	tomoj	'I feel uneasy about passing very large seqs to functions with apply
23:35	tomoj	no, you will have to write your own for that I believe
23:35	tomoj	but it's not very hard
23:36	j3ff	alright, thanks
23:36	j3ff	yeah
23:36	tomoj	most clojure doesn't like thinking about indices
23:36	_ato	,indexed
23:36	j3ff	yeah its because im implementing an algorithm into clojure
23:36	clojurebot	#<seq_utils$indexed__697 clojure.contrib.seq_utils$indexed__697@ec0f07>
23:37	_ato	,(apply max-key second (range 10000))
23:37	clojurebot	java.lang.IllegalArgumentException: Don't know how to create ISeq from: Integer
23:37	_ato	hmm
23:37	_ato	oh right
23:38	_ato	,(apply max-key second (indexed [8 2 4 9 5 5]))
23:38	clojurebot	[3 9]
23:38	_ato	(as in index 3, value 9)
23:38	j3ff	whoa cool
23:39	j3ff	thanks!
23:41	tomoj	ah I didn't know max-key existed
23:41	tomoj	nice
23:43	j3ff	is indexed part of a library?
23:43	_ato	clojure.contrib.seq-utils
23:43	j3ff	thanks
23:44	_ato	btw, about using apply, functions that take an arbitrary number of arguments like + and max are defined like: (defn max [x y & more])
23:44	_ato	that will happen is the first two values of the seq will get assigned to x and y and the rest of the seq to more
23:44	_ato	so that's really cheap
23:45	_ato	and then max will just deal with the first two cases and recurse
23:45	_ato	so it's usually about the same as doing reduce
23:46	_ato	,def max
23:46	clojurebot	java.lang.Exception: Unable to resolve symbol: def in this context
23:46	_ato	clojurebot: def max
23:46	hiredman	I seem to recall max using reduce internally
23:46	_ato	yep
23:47	hiredman	and I remember using reduce externally was faster than using apply max and max's internal reduce
23:47	hiredman	but I don't remember why
23:48	_ato	yeah, that's strange, in theory it should be doing almost exactly the same thing
23:48	_ato	just one more or two more function calls
23:49	hiredman	this was all gone over, maybe six months or so a go in here
23:52	tomoj	well
23:52	tomoj	when you apply a function to a huge seq
23:52	tomoj	does some large tail of the arguments just get left inside a seq, to be reduced inside the call?
23:53	hiredman	yes
23:53	tomoj	calling functions with a huge number of arguments always makes me feel uneasy
23:55	hiredman	for more than four args I like to use map destructuring