#clojure – 2008-06-03

2008-06-03

11:35	Chouser	Is there any more convient way of building an Object[][] from a vector of vectors of various constants, other than to walk the vectors and build up the array using (to-array)?
11:36	rhickey	no
11:41	Chouser	(to-array (map to-array data)) isn't too bad I guess.
11:41	Chouser	but that's an Object[] of Object[], which isn't the same as Object[][], is it?
11:41	rhickey	yes it is
11:41	Chouser	Here I'm running into my Java ignorance.
11:41	Chouser	hm. ok.
11:42	rhickey	no real multidimensional arrays in Java
11:42	rhickey	just arrays of arrays
11:43	Chouser	ok. So my "No matching ctor" is something else... ;-)
11:49	Chouser	Any relationship between PersistentVector and java.util.Vector?
11:50	rhickey	no
11:50	rhickey	I guess they are both java.util.Collections
11:57	lisppaste8	Chouser pasted "ctor confusion" at http://paste.lisp.org/display/61639
11:57	Chouser	I missing something, but I don't know what.
12:07	rhickey	you should be using into-array
12:08	rhickey	to build the dataArray
12:09	rhickey	btw such names as dataArray are ugly for Clojure, should only be used for Java names
12:10	rhickey	in any case to-array always yields an Object array, into array yields an array of the type of the first element
12:10	rhickey	into-array
12:10	rhickey	(def dataArray (into-array (map to-array data)))
12:11	rhickey	user=> (class dataArray)
12:11	rhickey	class [[Ljava.lang.Object;
12:12	rhickey	misunderstood what you were trying to imply by "Object[] of Object[]" before
12:14	Chouser	ah, cool. works perfectly!
12:15	Chouser	I should be using - between words instead of camelcase?
12:15	rhickey	yes please :)
13:26	Chouser	have people's opinions about (new Foo) vs. (Foo.) consolidated at all?
13:31	jgracin	I don't like the new new syntax. I find (new Foo) more consistent, logical and Lispy.
13:32	jteo	agreed.
13:37	cgrand	idem
13:40	Chouser	ok
13:45	Chouser	even though it makes this a lot longer?
13:45	Chouser	(-> urlstr URL. .openConnection .getContent InputStreamReader. BufferedReader.)
13:46	Chouser	And you'd have to do that backwards too, right? (new BufferedReader (new Input... (new URL urlstr)...))
13:50	rhickey	I think (Foo. args) is more lispy - makes for a named function vs generic new. You wouldn't want to have to say (call fname args) every time would you?
13:51	rhickey	also, nested ctors look more declarative that way
13:52	rhickey	-> is not very lispy but very convenient
15:09	fyuryu	I prefer (Foo. ...) over (new Foo ...) - looks better, especially when you pass args to the constructor
16:19	Chouser	so ... the opinions haven't consolicated much at all. ;-)
16:21	cgrand	I'll try to force me to use Foo. instead of new -- maybe I need to overcome a bias induced by familiarity :-)
16:21	rhickey	There was one benefit of CL's make-instance vs the defstruct generated make-x, and that was that the type truly was a parameter of the function - it was a symbol and could have a dynamic value. That's not the case for new, where it is syntax.
16:58	Chouser	Will a PersistentVectors handle sparseness efficiently, or should I use a Hash for that?
17:20	Chouser	any way to "initialize a class" without calling (. Class forName "Foo")
17:20	Chouser	[note: I don't really know what I'm talking about]
17:21	rhickey	Chouser: maps for sparse
17:21	rhickey	Foo
17:21	Chouser	thanks re: sparse
17:22	Chouser	I thought Foo would do it, but I'm trying to use java.sql.DriverManager, and unless I call forName first, it doesn't recognize the url I give it.
17:23	rhickey	name the specific driver you are using?
17:24	lisppaste8	Chouser pasted "org.postgresql.Driver" at http://paste.lisp.org/display/61660
17:31	drewr	Chouser: Did you (sql/register-driver "org.postgresql.Driver") ?
17:31	drewr	Sorry, that's based on the sql.clj from webjure.
17:31	drewr	But you can see how he does it in there.
17:33	Chouser	He calls (. Class forName "Foo")
17:34	Chouser	Nothing terribly wrong with that, other than having a class name in a string.
17:34	Chouser	I was hoping for something like (. Foo init)
17:50	Chouser	gah. more annoyingness -- I have to include the postgresql jdbc .jar in my commandline classpath. Adding it with add-classpath doesn't work.
17:51	Chouser	If I use add-classpath, (prn org.postgresql.Driver) works, but (. Class forName "org.postgresql.Driver") fails.
17:52	rhickey	you can't use add-classpath to expose things to classes loaded above Clojure in the classloader hierarchy, like the sql library
17:52	Chouser	yeah, I see that.
17:53	Chouser	It seems to be to be a failing in the DriverManager API. I should be able to pass it a class to use.
17:53	Chouser	ooh!
17:53	rhickey	I bet org.postgresql.Driver works now
17:53	rhickey	without classForName
17:55	Chouser	now? you checked in changes?
17:55	rhickey	no, with the jar in the commandline classpath
17:56	Chouser	oh. no, that's what I was doing originally.
17:56	Chouser	I double-check.
17:57	Chouser	nope. java.sql.SQLException: No suitable driver found for jdbc:postgresql:ivytech
17:57	Chouser	I need the jar on the command-line and forClass in the code.
18:03	Chouser	it looks like org.postgresql.Driver has a anonymous class-static function (??) and perhaps it's not getting called without forName?
18:04	Chouser	http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/jdbc/pgjdbc/org/postgresql/Driver.java.in?rev=1.73
18:07	Chouser	Instead of forClass I can use: (. java.sql.DriverManager registerDriver (org.postgresql.Driver.))
18:07	Chouser	but I still need the .jar on the command-line.
18:09	rhickey	jar on the top level classpath is mandatory in this case, a child classloader can't provide classes to its parent
18:10	Chouser	I guess I don't really understand classloaders. I figured if I was passing the class directly that that would work.
18:11	Chouser	that nasty old classpath-add function I posted a while ago works, though, since it adds the classpath directly to the system classloader.
18:12	rhickey	right, but don't expect to do that on a server
18:13	Chouser	can I not cause the child classloader to handle java.sql.DriverManager as well, so that it can see classes I load later?
18:13	rhickey	add-classpath is a utility to allow you to grab a lib and start using it without restarting. If you end up using it, it should end up in tha classpath
18:14	Chouser	the reason I'm attracted to it in this case is that it would allow my app to dig around in the filesystem looking for an appropriate .jar.
18:14	rhickey	correct classloaders delegate to their parents first, and mine do too, so the system classloader will load java.sql.DriverManager
18:15	Chouser	Hmph.
18:16	rhickey	a database driver is not something to find at random on your filesystem :)
18:18	Chouser	I guess I just don't "get" Java.
18:19	Chouser	With python, perl, ruby, etc. when a support library is installed on a system, it's installed in such a way that a program can simply ask for it and start using it.
18:20	Chouser	Java requires this extra manual step of setting the classpath.
18:20	Chouser	On systems I've used, the classpath provided by default includes no support libraries, just the core Java stuff.
18:21	Chouser	So what's an application provider to do? One option would be to look at standard places where .jars might be installed, load them, and use them. But apparently I can't even do that.
18:21	rhickey	ship the jars you use
18:22	Chouser	Jars can include native binary code, can't they?
18:22	rhickey	jars are just packaging, but normally, no, just bytecode
18:24	Chouser	Is that really the "normal" answer? It looks like there's a different postgres driver for each major version of postgres, even though they have the same Java API.
18:25	Chouser	should I include all of them and hope one of them matches the db server installed on the target system?
18:25	rhickey	This is a hypothetical situation, in reality people test pretty extensively on their exact target platform/version
18:27	rhickey	If you were shipping JDBC-based software you'd have nothing to do with the driver setup - an admin would do it and configure it and pass you a connection string and it would work
18:27	Chouser	well, I'm sorry to vent here. I'm not really trying to make you defend Java. But this isn't hypothetical -- I'm providing a small app to be run by our developers. We support a couple versions of postgres and mysql, and I'd like my app to work out of the box for them.
18:28	rhickey	SQL drivers are an admin function - have your app take a connection URL
18:31	rhickey	if there's no server and no admin, at least take that logic out of your app
18:34	Chouser	I guess. It seem unfortunate that installing the driver isn't enough, you also have to configure the classpath. Is there some reason the default Java classpath isn't set up to include every .jar installed on the system by default?
18:34	rhickey	versioning, security
18:43	dudleyf	rhickey: So you're not in favor of having a Clojure "library path"?
18:43	Chouser	perl, python, ruby, and even linux runtime linking for native binaries have all solved those problems satisfactorily. I guess I can provide a shell script and .bat file that bootstrap my app, just like every other Java app has had to do.
18:45	rhickey	your kidding, right? none of them have security, Ruby and Python have no multithreaded story, Java torches them all for performance etc etc
18:45	rhickey	you're
18:47	rhickey	I'll admit Java is less carefree, but when you have serious work to do, it's a serious tool
18:48	rhickey	http://www.madstop.com/ruby/ruby_has_a_distribution_problem.html
18:49	rhickey	http://docs.python.org/api/threads.html
18:50	rhickey	there's no free lunch
18:50	Chouser	this issue has nothing to do with support for threads. I'll read that ruby link.
18:51	rhickey	It has to do with comparing platforms based on one dimension - if you switch to Python for its carefree lib distribution, you get GIL with it
18:53	rhickey	No one likes the classpath, but everyone gets over it
18:53	Ycros	but does that really matter if you have like the python processing package?
18:53	rhickey	Look, I didn't start comparing langs/platforms...
18:53	Ycros	there's a lot of argument against threading in general
18:54	Ycros	I see your point though
18:54	Chouser	I'm not talking about switching to Python. I'm talking about fixing Java and/or using clojure to work around Java weaknesses.
18:54	rhickey	Ok, so the best route is not to fight Java but to understand it
18:55	Chouser	The only reason I brought up other platforms is to demonstrate that this particular problem (convenient library distribution) has been solved many times.
18:55	rhickey	What you now consider a weakness you might not when you are building a different kind of app
18:56	Ycros	you can set the classpath through an environment variable. If your machines have one configured, then conceivably you could install your dependencies in the same place across all your machines
18:57	rhickey	Part of the classpath/jar story has to do with application isolation - to the extent apps are self contained they can run in isolation and there aren't the - "please install this lib on the server' aspects
18:58	rhickey	there are plenty of admins who won't install the Ruby runtime, never mind its libraries
18:58	Ycros	I've certainly distributed python apps with my own versions of libraries bundled with them, and I've done that with ruby apps as well
18:58	dudleyf	rhickey: Will there ever be a "clojure" executable, or will Clojure applications always need a shell script launcher like Java?
18:58	Ycros	for something like rails, you _do not_ want to run against system installed versions of rails and most of your deps
18:59	rhickey	dudleyf: executables are not portable, so not my thing, but nothing is stopping someone from making a bundler for each platform
19:01	Lau_of_DK	What is the recommended "main loop" to prevent instant exit when running clojures from the commandline?
19:01	dudleyf	rhickey: "executable" should have been in quotes, a shell script would work
19:01	dudleyf	but a standard mechanism for executing Clojure code
19:02	dudleyf	So that you don't have to bundle a launcher script with every Clojure application you want to share
19:02	Ycros	couldn't you package them up as jars? then you'd be running java -jar <your jar>
19:03	Ycros	not sure if you'd need a bootstrapper class of some sort
19:05	Lau_of_DK	What is the recommended "main loop" to prevent instant exit when running clojures from the commandline? Just to keep the main messagepump running for the GUI.
19:11	rhickey	Lau_of_DK: does the latest clojure.lang.Script not work for that?
19:12	Lau_of_DK	Sure, .Script executes that file, but if the file loads a frame or such, without a loop that must be broken by the GUIs exit signal, then the frame just loads and disappears, which is should. Im just wondering how you would do something similar to C's while (true) { } in Clojure
19:14	rhickey	If you write an app that mimics this, it should work the same:
19:14	rhickey	http://java.sun.com/docs/books/tutorial/uiswing/examples/start/HelloWorldSwingProject/src/start//HelloWorldSwing.java
19:16	Lau_of_DK	Alright, exactly what I needed to see, thanks
19:19	drewr	http://reddit.com/r/programming/info/6lv71/comments/
19:37	dudleyf	rhickey: Sorry to keep harping on this, but are you saying you wouldn't ever include a "clojure" script that runs clojure.lang.Script or .Repl as appropriate into the distribution?
19:37	dudleyf	Just trying to clarify, not annoy, I promise ;-)
19:38	rhickey	If someone wants to make a set of scripts for all platforms, then maybe. It's not something I personally am going to work on.
19:40	dudleyf	That's cool. I just wanted to know if you were philosophically opposed, or just uninterested.
19:40	dudleyf	What are "all platforms", BTW?
19:40	rhickey	It's a ripe area for contributions :)
19:41	rhickey	OS X, Windows, Linux
19:42	albino	Chouser: python has PYTHONPATH like java's CLASSPATH, just not as crippled (you can point it to directories)
19:42	rhickey	Sorry all if I seemed a bit cranky on the library thing, but I don't think these scripting languages have solved problems the Java ecosystem hasn't. They haven't even been applied to a tiny fraction of the problem domains Java has, from phones to CERN. I think it's easy to make simple things simple, but much harder to make hard things possible. Perhaps in making hard things possible Java has made easier things less simple. But I'm pret
19:43	albino	Chouser: although python does have site-packages which is fairly nice for being a place to drop 3rd party libraries
19:45	albino	that seems like a fun project, creating a native binary for clojure for different platforms
19:47	Lau_of_DK	Yea, it would be a great plus
19:47	Lau_of_DK	That - and a boatload of tutorials to attract more developers :)
19:48	albino	That last one is probably on us, the community hanging out in the IRC channel
19:49	Lau_of_DK	Yea. Would be good to set up some sort of website for it, where we could all contribute, and then the tutorials could be looked through, optimized, whatever, and posted on some website or something. I think that would be good
19:49	Lau_of_DK	But I'm not sure how many people are attracted to Clojure that dont have a strong background in Lisp?
19:50	dudleyf	Lau_of_DK: I'm one.
19:50	Lau_of_DK	k.. so there's 1 :)
19:50	albino	That doesn't seem like much of a reason to stop writing tutorials
19:50	albino	who cares where they come from
19:50	Lau_of_DK	hehe, albino, it was a different point
19:50	Lau_of_DK	It was not related to the tutorials
19:50	albino	oh
19:50	Lau_of_DK	I was more along the thought-train of attracting people to the language
19:50	albino	The "But" got me
19:51	dudleyf	rhickey: You're exactly right. But just because Java has made easy things complicated doesn't mean that Clojure needs to follow suit ;-)
19:51	Lau_of_DK	albino, the but ?
19:52	rhickey	I personally don't find the classpath all that complicated - classloaders are a bit tricky
19:52	rhickey	I would love for the more experienced here to contribute to the Wiki...
19:52	dudleyf	I'm still mostly talking about just running a single small bit of code
19:54	dudleyf	The library thing is a problem that I don't think anybody's gotten right yet
19:55	dudleyf	But it's better to stay out of the game than to bake a bad idea into the language
19:56	albino	Lau_of_DK: you started your setnence following the one about writing tutorials with "But", that made me think the two statements were connected.
19:57	dudleyf	bbl
19:59	Lau_of_DK	Sure, I can see I wasn't quite clear :)
20:00	rhickey	dudleyf: point taken about small bits of code. I guess I have a certain bias as I mostly write pretty complex apps like broadcast automation systems, schedulers, election projection systems, etc. So all the input re: scripting-level app issues is informative...
20:06	rhickey	poll: coming to Clojure, primary prior exposure to: Java/Lisp/Python/Ruby/Haskell/Other?
20:07	Lau_of_DK	Lisp
20:08	albino	Python + (tiny bit of Java)
20:09	albino	rhickey: but I don't count I've only written like 15 lines of clojure
20:16	Ycros	I primarily use python, ruby, php, javascript, I did C# for 2.5 years but I haven't touched it in a few months, I've been dabbling in common-lisp, erlang and OCaml
20:16	Ycros	now I'm dabbling in Clojure :)
20:19	Ycros	actually, before doing C#, I was doing Java for about 2 years
20:20	Lau_of_DK	I think the step from another Lisp to Clojure is a natural one. I was happy to see that although Ive never touched Java, that my C# experiences translated almost directly, with no surprises. I think it takes a little more eye-opening for traditional Java/C# programmers to make the switch though
20:21	rhickey	It'll be interesting - I'm speaking to a Java group this Thursday and it will be the first time I'll really be explaining the Lisp aspect of Clojure from scratch
20:22	Lau_of_DK	Whoa - I think you should really consider doing a screencast of that - If for no other reason, then I really wanna hear how you go about it
20:22	Lau_of_DK	:)
20:24	Chouser	significant work in: perl, python, ruby, C, C++, JavaScript, and quite a while ago some Pascal and TCL/TK. some exposure to: Java, Scala, lisp/scheme, Visual Basic.
20:25	rhickey	Chouser: yay - you're back! (afraid I'd driven you off) :)
20:25	Chouser	oh, not at all. I'm hope I didn't annoy you too much.
20:26	Chouser	I was eating dinner, putting kids to bed, etc. ;-)
20:26	Chouser	In my attempts with OCaml, haskell, and erlang, I always came out the loser. Actually, maybe Java's in that category too.
20:27	Lau_of_DK	rhickey, seriously, would you consider doing a screencast of that talk ?
20:28	rhickey	I intend to try - last time the screencast software crashed my machine during the presentation - I guess I'll have to pause every hour or so :)
20:28	Lau_of_DK	Come on, how long would it take to write new sc software in clojure? :)
20:30	albino	Chouser: Quite a laundry list there
20:30	Lau_of_DK	But I think that kind of talk could really draw in alot of Java/C# programmers, because going from that background to Lisp can be a pretty unsatisfying feat if you dont get proper guidance.
20:30	rhickey	yes, it's a gap in the Clojure materials right now
20:30	Chouser	albino: I used to think so, but recently I've been noticing that most of those languages have a lot in common, compared to some others.
20:31	rhickey	and referring people to other Lisp tutorials is a mixed bag as they don't quite match up with Clojure
20:31	albino	The other screencast seemed to get some questions I would expect from non-lispers
20:31	albino	Chouser: I would fail at trying to do significant amounts in that many languages, my brain is too small
20:32	Chouser	I'm on a quest to find the "best" language. Of course my definition of best changes with each language I learn...
20:32	Chouser	...and each project I work on.
20:33	albino	Chouser: Ahh, aren't we all on that quest
20:33	Lau_of_DK	rhickey, true. But I think as a principle, if you don't know Lisp then the combination of 1 Paul Graham article on the success of viaWeb, Practical Common Lisp and the SICP videos can be a good way to get going.
20:33	Chouser	Clojure's the best yet. :-)
20:33	albino	Wow, a viaweb believer
20:34	albino	I keep trying to get time to go through factor, common-lisp, or clojure. I haven't yet made the time work.
20:34	rhickey	I do think Clojure is substantively different from other Lisps, and much more approachable - I'm biased of course :)
20:34	Ycros	Chouser: I've come to the conclusion that there is no best language
20:34	albino	Chouser: any smalltalk?
20:34	Ycros	Chouser: I've happily settled on Python as being my all-round best language for most things though
20:35	Lau_of_DK	rhickey, I dont deny it, but its still a valuable background. When you really get the sense of how much you can do with the core elements of a Lisp, and youre all set, you've got your macros ready, emacs is fired up, and then somebody says "AND, you can use every Java library in the book" - well, then you know the rest, its a pretty motivating thing :)
20:35	Ycros	rhickey: you get to use all the Java libraries, AND you're ditching legacy apis - one thing that I disliked about common lisp
20:36	Chouser	Ycros: no best language yet :-)
20:38	Ycros	Chouser: I'm not sure how to define a best language
20:38	Ycros	like, I don't think I could put together a list of features, and say "the best language has these features"
20:40	Chouser	Can't a language have every feature? Or at least, allow you to build any feature you need?
20:40	albino	PG likes to think in terms of the 100 year language
20:41	rhickey	Lau_of_DK: I'm not sure - most Lisp tutorials have pictures of cons cells early on - that's totally not relevant for Clojure
20:41	Chouser	And Yegge likes to think of the Next Big Language. shrug
20:43	Ycros	Chouser: I'd love static typing with type inference by default, but dynamism where you need it
20:43	Lau_of_DK	rhickey, alright, maybe you're right, we'll wait and see :)
20:43	Chouser	I think most programmer have heard of lisp and already formed an opinion. I would guess most who are happy to use Java probably have unfavorable opinions of lisp.
20:44	Chouser	whether it's the parens, the libraries, or the lack of static types. I don't know if presenting Clojure as a lisp is the best way to win them.
20:44	Chouser	Ycros: yeah, me too. But I don't know enough to accurately describe that, let alone build such a beast. I'll be curious to see where JavaScript ends up there.
20:45	Chouser	Rhino with PersistentHashes underneath? ;-)
20:45	rhickey	Chouser, that's true, but I don't know a more concise way of implying code-as-data/syntactic abstraction/dynamic etc etc
20:47	rhickey	but the biggest pushback I've gotten from devs is on the practicality issues, at least when trying to sell them on Common Lisp. Those same guys are crazy about Clojure
20:47	rhickey	libraries, interop with existing systems
20:47	Chouser	rhickey: yeah, I'm sure that last point is true. That's why Yegge is on the JVM, because that's all Google will let him do.
20:48	Chouser	but for those first two features (code-as-data, syntactic abstration), if you understand those and really think they're important, you're already a lisp fan whether you know it or not.
20:48	rhickey	Google/Amazon/Yahoo are on the JVM because it works
20:49	Chouser	Google also uses a lot of Python. But I'm not arguing that point. ;-)
20:49	Chouser	I've been trying to think of how to highlight the similarity between clojure and non-lisps"
20:49	Chouser	literal vector and hash syntax.
20:49	rhickey	Chouser: right tool for each job, until something more general comes up
20:50	rhickey	Chouser: yes, I'm starting with the data structure literals, then - surprise! that's the syntax too!
20:50	Chouser	most languages use basically a prefix notation, lisp is only different on where the first paren goes (func a b) vs. func(a, b)
20:50	Chouser	rhickey: yeah, that's good.
20:51	rhickey	interactively playing with Java libs is something they can't do in Java
20:51	Chouser	I think if I can avoid examples that include math, maybe they'll stop noticing the prefix notation early.
20:52	rhickey	heh
20:52	Chouser	rhickey: yeah, the REPL is good. There are people who like python and ruby almost entirely because of that.
20:52	Chouser	and there's something almost magical about building a GUI interactively at the REPL (like the ant demo)
20:53	rhickey	yeah
20:53	Lau_of_DK	Its a unique feature, thats for sure
20:53	Chouser	TCL/TK was my first experience with that, and it almost made up for the terrible language.
20:53	Chouser	bbl
20:54	rhickey	also, if they do any multithreading Clojure is like complete magic
20:56	Lau_of_DK	Yea its no joke - Still - genious as it is - this immutable persistance takes a little getting used to
21:05	Lau_of_DK	Question: Do I need to call close to my open i/o streams, or does Clojure handle that?
21:06	Chouser	right. So that was my thought -- hilite the similarities between clojure and other language (Java, C, Python) syntax, and then move on to clojure's more unique features: REPL, persistent structures, convenient functional apis, ... not sure how much more time there would be.
21:06	Chouser	Lau_of_DK: (doc with-open)
21:07	rhickey	I've got 2 hours this time
21:08	albino	rhickey: you don't happen to be streaming live, do you?
21:08	Lau_of_DK	Chouser, exactly what I needed, thanks
21:11	rhickey	I do think Clojure, like Lisp/Haskell/Erlang, demands a certain intellectual curiosity, it's hard to make an instantly appreciable argument for its practicality
21:11	rhickey	for a lot of people programming is just a job
21:19	Lau_of_DK	Im not sure. I think any Lisp offers a whole new dimension to the term, reuseable code, and thats pretty practical
21:20	rhickey	when I first started ranting about Lisp all my friends thought I was crazy
21:21	Lau_of_DK	Sure, but we're they saying that based on Lisp or your personality?
21:21	Lau_of_DK	(joke - dont kill me)
21:22	rhickey	I wrote a new programming language, which proves I AM crazy
21:22	Lau_of_DK	hehe, you have it in writing
21:27	Lau_of_DK	I'm wondering, what technique would you use to loop over the lines of a file using BufferedReader, collecting the lines when reaching null/nil ?
21:28	rhickey	(doc line-seq)
21:33	Lau_of_DK	(defn get-txt-file
21:33	Lau_of_DK	[in]
21:33	Lau_of_DK	(let [reader (new BufferedReader (new FileReader in))]
21:33	Lau_of_DK	(with-open reader
21:33	Lau_of_DK	(line-seq reader))))
21:33	Lau_of_DK	This throws an exception: No matching method found: close
21:33	Lau_of_DK	but reader has a .close method
21:34	Chouser	(with-open reader (new ...) (line-seq ...))
21:34	Chouser	skip the let
21:35	Chouser	this is one of the primary drawbacks of lisp syntax (or non-syntax) -- few hints to differentiate args. Clojure's vector and map syntax helps a bunch, but with-open doesn't use those.
21:36	Lau_of_DK	k
21:36	Chouser	In a python-like language, you might say with-open(reader=foo): body, making it obvious that with-open takes 3 different kinds of args.
21:37	Chouser	of course then you lose macros, and that's just not worth it.
21:37	Lau_of_DK	Maybe Enclojure can help make that bit, a little easier
21:37	Ycros	in python I'd use the new with statement: "with something() as s:"
21:37	Lau_of_DK	But would you say this is correct Clojure
21:37	Lau_of_DK	(defn get-txt-file
21:37	Lau_of_DK	[in]
21:37	Lau_of_DK	(let [reader (new BufferedReader (new FileReader in))]
21:37	Lau_of_DK	(with-open reader
21:37	Lau_of_DK	(line-seq reader))))
21:37	Lau_of_DK	argh
21:37	Lau_of_DK	2 sec
21:37	Lau_of_DK	(defn get-txt-file
21:37	Lau_of_DK	[in]
21:37	Lau_of_DK	(with-open reader (new BufferedReader (new FileReader in))
21:37	Lau_of_DK	(line-seq reader)))
21:38	Chouser	I do wonder if some of these vaguely let-like macros would benefit from using a vector like let does, even if they only ever take 2 items.
21:38	Chouser	Lau_of_DK: does it work?
21:38	Lau_of_DK	No, it throws an IO exception
21:38	Chouser	Ycros: sure. and in clojure, you can write your own. ;-)
21:38	Lau_of_DK	And at the bottom it gives some scrambled output from the file
21:39	Chouser	(line-seq reader)))
21:39	Chouser	oops, sorry.
21:40	Ycros	Chouser: aye
21:41	rhickey	Chouser: maybe so
21:43	Chouser	Lau_of_DK: This has bitten me a couple times.
21:43	Chouser	Lau_of_DK: the problem is that line-seq is lazy, so with-open is closing your reader before you're done.
21:43	Lau_of_DK	Yea I imagined that was the problem
21:44	Lau_of_DK	Quick solution: Is there a non-lazy reader?
21:44	Lau_of_DK	Or can I force it to produce a string before returning? (preffered)
21:45	Chouser	you could wrap line-seq in doall
21:45	Chouser	(doall (line-seq reader))
21:45	Lau_of_DK	ok. But I think you guys need to come up with a solution for the problem with (with-open). Its going to come back and bite you if you dont :)
21:45	Chouser	oh, a single string? (apply str (line-seq reader))
21:46	Lau_of_DK	Alright, thanks alot Chouser
21:46	Chouser	np
21:51	Ycros	wait, what was the problem with with-open?
21:51	Ycros	ambiguity of arguments?
21:51	Lau_of_DK	That it closes before lazy-streams are evaluated
21:52	Lau_of_DK	(unless you evaluate them straight off of course)
21:52	rhickey	Lau_of_DK: what else could it do?
21:53	Lau_of_DK	Im not sure what you be a clever way of solving it.
21:53	Lau_of_DK	If it indeed needs to be "solved"
21:53	rhickey	the whole point of it is that it bounds the open scope, so you have to consume it inside
21:54	Lau_of_DK	Well... when you put it like that
21:54	Lau_of_DK	:)
21:54	Lau_of_DK	Anyway, its 03:19 AM here, so I gotta hit the sack. Sweet Clojure dreams to you guys when you get that far
21:57	rhickey	I've added support for : as a non-repeating, non-terminal constituent character in symbols
21:57	rhickey	so now you can deal with XML namespaces
21:59	Chouser	non-repeating, eh? Just don't want to give us enough rope...
21:59	rhickey	do you need repeating?
21:59	Chouser	nope
21:59	rhickey	thought not :)
21:59	Chouser	not yet...
21:59	Chouser	:-)
21:59	dudleyf	non-repeating?
21:59	rhickey	reserving :: as potential syntax
22:00	dudleyf	Ah
22:00	Ycros	so are people leaning towards emacs or towards other IDEs?
22:01	dudleyf	I've switched to emacs
22:01	Ycros	I'm using netbeans at the moment, mainly because I'm using netbeans for other stuff as well (ruby on rails stuff)
22:03	Chouser	I'm trying to get into enclojure, but I'm still far more comfortable with vim and a shell prompt. ...as usual.
22:04	Ycros	wasn't there a slime-like thing for vim somewhere?
22:13	Chouser	dunno.