#clojure – 2009-09-11

2009-09-11

00:15	claritas	anyone know where to adjust the indentation in slime? when I write nested hash/array literals it only indents by one space and makes it hard to read
00:54	travisbrady	,(type '(1 2 3))
00:54	clojurebot	clojure.lang.PersistentList
01:01	travisbrady	what does the single quote do in the above?
01:06	JAS415	holds evaluation
01:06	JAS415	otherwise it would be have to treat 1 as a function
01:07	JAS415	,(type (1 2 3))
01:07	JAS415	,(type (list 1 2 3))
01:08	clojurebot	java.lang.ClassCastException: java.lang.Integer cannot be cast to clojure.lang.IFn
01:08	clojurebot	clojure.lang.PersistentList
01:08	JAS415	,(type (first '(list b c)))
01:08	clojurebot	clojure.lang.Symbol
01:09	JAS415	(,type (first (list 1 2)))
01:09	JAS415	,(type (first (list list 1 2)))
01:09	clojurebot	clojure.lang.PersistentList$1
01:10	JAS415	,(type clojure.lang.PersistentList$1)
01:10	clojurebot	java.lang.Class
01:10	JAS415	,(type 'list)
01:10	clojurebot	clojure.lang.Symbol
01:22	travisbrady	JAS415: thanks, but what does it mean to 'hold evaluation'?
01:31	JAS415	it means that for example, symbols aren't converted into the data they represent
01:31	JAS415	which is why 'list returns type symbol
01:32	JAS415	whereas the other one returns the persistentlist class
01:32	JAS415	,(type +)
01:32	clojurebot	clojure.core$_PLUS___4094
01:32	JAS415	^^ function
01:32	JAS415	,(type '+)
01:32	clojurebot	clojure.lang.Symbol
01:32	JAS415	symbol
01:32	JAS415	so is kind of like the opposite of eval
01:32	clojurebot	eval is sometimes useful - but only sometimes
01:33	JAS415	oh clojurebot, eval is always useful, but not normally in your code
01:34	JAS415	so like you can do
01:34	JAS415	(eval '(+ 2 3))
01:34	JAS415	,(eval '(+ 2 3))
01:34	clojurebot	DENIED
01:34	JAS415	ahh
01:34	JAS415	clojurebot wont' let you use eval
01:34	JAS415	as it can be used nefariously
01:34	JAS415	but in your repl you can do that
01:36	JAS415	,(type '(fn [x] (identity x)))
01:36	clojurebot	clojure.lang.PersistentList
01:36	JAS415	,(type (fn [x] (identity x)))
01:36	clojurebot	sandbox$eval__6948$fn__6950
02:28	travisbrady	anyone know of a simple example showing how to loop over stdin in clojure?
02:48	JAS415	loop over std in in what way?
02:48	JAS415	like read a file?
02:48	JAS415	look at clojure.contrib.duck-streams
02:48	JAS415	can also do java calls if you must
02:56	manic12	is there a print-object function in clojure which can be extended/overloaded?
02:57	dms_	there is print-dup.
03:03	manic12	thanks
03:03	manic12	I'm not sure how to correctly add a method to it though
03:08	dms_	Its just a normal mulit-method. To modify printing strings for instance, you will have something like (demethod print-dup java.lang.String [x writer] (pr "my-string" "s"))
03:11	dms_	Hmm.. There also seems to be print-method which dispatches on (type..).
03:11	dms_	(doc print)
03:11	clojurebot	"([& more]); Prints the object(s) to the output stream that is the current value of out. print and println produce output for human consumption."
03:22	dms_	ok. i really dont understand print-dup and friends as much as i thought i did.
03:25	manic12	no, I figured it out
03:26	manic12	if you want to see it I'll paste it somewhere, I looked at the clojure source
03:27	dms_	I just looked at core_print.clj. Now it makes sense. Thanks.
04:10	Bercilak	Has there been anything like doctests done for clojure?
04:10	Bercilak	I read about the :test metadata in Programming Clojure, but it doesn't seem like anybody uses that in the wild.
04:19	eevar2	Bercilak: unit testing? :use clojure.test
04:20	Bercilak	I've been reading the clojure contrib docs, and I really want to like them but there just aren't enough examples.
04:21	Bercilak	I come from a python background, and I love what doctests have done culturally for python.
04:22	Bercilak	Simple, verified examples are weaved directly into the documentation...
04:22	Chousuke	I think with clojure it's more common to just test your function until you're sure it works ;P
04:22	Chousuke	and then move onto another one
04:23	eevar2	Bercilak: i'm sure the clojure api docs could use more examples, yea
04:23	Chousuke	but hm, while I'm not aware of any doctest stuff, Rich did add support for pre- and post-assertions at some point.
04:24	Chousuke	I haven't seen that used much either though
04:24	somnium	I think immutability + isolated side-effects remove a lot of the need for testing in languages like Python/Ruby
04:24	hiredman	oh yeah
04:24	Bercilak	My name just showed up on the clojure contributor page so I'm giddy to do something useful. :-) Examples in documentation are always good.
04:25	Chousuke	did you already join Assembla and the dev group?
04:25	Bercilak	assembla yes, not the dev group yet
04:26	Bercilak	I'm not even really interested in the testing aspect of it. It's more about the documentation, but having the documentation verified as correct.
04:26	Bercilak	I was kind of hoping that :test was in wide use, because that could be pretty easily automatically converted into documentation.
04:27	Bercilak	I'll look at doing that with assertions, but I might also whip up some code for doing clojure doctests...
04:27	Chousuke	it shouldn't be too difficult. :)
04:28	Bercilak	:-). Nope. Just making sure there wasn't something obvious I was missing...
04:28	Bercilak	I really like clojure.
05:56	ol3`	hello, how do I define vars which should not be exported?
05:58	dms_	(def #^{:private true} myvar [1 2 3])
05:58	dms_	That keeps the var private. There is defn- for functions.
05:58	ol3`	dms_: thanks
05:59	dms_	might also want to see clojure.contrib.def. I remember seeing some related utilities.
06:42	ol3`	(doc ns)
06:42	clojurebot	"([name & references]); Sets ns to the namespace named by name (unevaluated), creating it if needed. references can be zero or more of: (:refer-clojure ...) (:require ...) (:use ...) (:import ...) (:load ...) (:gen-class) with the syntax of refer-clojure/require/use/import/load/gen-class respectively, except the arguments are unevaluated and need not be quoted. (:gen-class ...), when supplied, defaults to :name correspo
06:52	ambient	danm, it's really slow to write the functional stuff, but the code is damn _compact_
06:52	ambient	just a few lines does more than 50 lines of Java
06:56	LauJensen	Hey guys
06:57	liwp	LauJensen: good morning
06:57	cgrand	hey!
06:58	liwp	it's pretty quiet here these days during the day (european time)
06:58	liwp	or at least it seemed busier a little while back
06:58	liwp	maybe it's all in my head
06:58	achim	hi!
06:58	achim	does anybody know a decent java decompiler? most of those showing up on google seem to be either very old or dubious shareware gui apps
06:58	liwp	achim: doesn't the jdk include some sort of decompiler?
06:59	liwp	achim: do you want to decompile class files to java source or byte code (asm)?
07:00	achim	liwp: .class -> .java, preferably
07:00	liwp	the thingy in the jdk 'decompiles' classes to byte code so you can look at the byte code that the compiler produced, so possibly not what you were looking for
07:00	liwp	ok
07:00	LauJensen	liwp, I sense a little slowing down of our community as well
07:00	achim	i'm afraid i can't read asm all that well
07:01	liwp	achim: I think all the decompilers I've looked have always been a little clunky. Not a lot of commercial use for such a tool
07:01	liwp	achim: the java byte code is quite easy to read since the JVM is a stack machine
07:01	liwp	i.e. things are put on the stack and then subsequent instructions operate on the operands that are on the stack
07:02	liwp	it takes a little practise to get used to it (and I'm in no way an expert), but after that it's relatively simple. A lot easier than x86 asm
07:02	liwp	(lunch)
07:35	powr-toc	What's the syntax for accessing a java inner class in clojure?
07:37	powr-toc	(OuterClass/InnerClass.) doesn't work
07:37	powr-toc	nor does (OuterClass.InnerClass.)
07:39	arbscht	OuterClass$InnerClass
07:39	powr-toc	ahh yeah... just found it as you said :-)
08:03	LauJensen	Do we have an installer like izPack for Scala?
08:18	powr-toc	Is there a macro that allows you to def a var with a docstring?
08:23	LauJensen	Do you need a macro for that?
08:23	Chouser	powr-toc: in contrib there's a defvar
08:24	Chouser	powr-toc: or you can say (def #^{:doc "my doc string"} foo 5)
08:47	AWizzArd	tomoj: so far there is not such a starter guide for fnparse. You can try the wiki, there is some documentation. And just try to use (lit ...) in the beginning, that can get you started.
10:17	ol3`	(doc ~io!)
10:17	ol3`	,(doc ~io!)
10:17	ol3`	,(doc io!)
10:17	clojurebot	java.lang.ClassCastException: clojure.lang.PersistentList cannot be cast to clojure.lang.Symbol
10:17	clojurebot	java.lang.ClassCastException: clojure.lang.PersistentList cannot be cast to clojure.lang.Symbol
10:17	clojurebot	"([& body]); If an io! block occurs in a transaction, throws an IllegalStateException, else runs body in an implicit do. If the first expression in body is a literal string, will use that as the exception message."
11:23	rhickey	stuartsierra: latest rdfm is approaching the model I am looking towards, feedback welcome (I know, docs :)
11:29	rhickey	lisppaste8: url
11:29	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
11:32	stuartsierra	cool
11:32	lisppaste8	rhickey pasted "fiddling with rdfm" at http://paste.lisp.org/display/86930
11:32	stuartsierra	I keep reading "rdfm" as "RTFM".
11:32	rhickey	now has transactions and assoc/dissoc model
11:32	rhickey	stuartsierra: right, it's Brooklynese :)
11:32	stuartsierra	got it
11:33	rhickey	looking for better name
11:35	Chouser	~I was trying to think of a better name, and getting nowhere, then suddenly it came to me:
11:35	clojurebot	CLABANGO!
11:37	Chouser	rhickey: would you have any interest in proxy generating automatically-named methods for base class's protected fields and methods?
11:39	rhickey	Chouser: my most recent thoughts were that I think it will be the best use of resources to layer reify/proxy, so the circumscribed part (reify) can be thought of as portable Clojure while the icky bits (protected access, ctors) part of the proxy superset, proxy being an interop construct
11:40	Chouser	I like the separation of concerns for refiy vs. proxy. Are you also saying that proxy would be re-engineered to be implemented using reify?
11:40	rhickey	putting more work into the (much slower) proxy seems a waste, and the pressure on reify to supplant proxy will be great
11:40	rhickey	Chouser: yes, reify + more work == new proxy
11:41	Chouser	ok
11:41	rhickey	I don't think many are leveraging the dynamic aspect of proxy, but if so we can find a new name
11:42	Chouser	ok
11:42	Chouser	so perhaps java-specific features as options to reify that are marked as non-portable?
11:43	rhickey	once based on reify you won't need generated wrappers for protected access
11:43	Chouser	then proxy can be just a macro that expands to java-only reify
11:43	Chouser	oh. oh, right.
11:44	rhickey	Chouser: I think right now the distinction matters only to me. But what I fear is that people will write new code using reify/proxy as Java-in-parens. proxy should only be used for some-badly-designed-library-is-forcing-me-to-do-this situations
11:46	Chouser	would still have an issue with ctor args + closures
11:48	rhickey	that depends, right now proxy only let's you flow through ctor args to super ctor, it doesn't have exposed ctor of its own per se
11:49	Chouser	oh, right the ctor args issue was using reify to provide a base class.
11:52	Chousuke	maybe (reify [Foo] {:host java} ...)
11:54	Chouser	Chousuke: I was going for something sufficiently onerous that one would definitely prefer using 'proxy' instead
11:55	Chousuke	Chouser: okay, well {:allow-host-features #{feature1, feature2 ...}}
11:56	Chousuke	though that might be too onerous :P
11:59	Chouser	so the idea is to discourage the use of 'reify' for purely interop cases. But things like ctor args would likely be available for interop on almost all hosts
12:01	Chouser	proxy even on reify would still need a way to call super class methods that have been overridden
12:01	Chouser	which again reify may not need, depending on the design of the no-arg ctor base class.
12:01	rhickey	(.super-whatever this ...)
12:02	Chouser	auto-named methods of the new class
12:16	AWizzArd	rhickey: I think there is a type at https://www.assembla.com/spaces/clojure-contrib/milestones where it says "... decide to work on the and ..."
12:16	AWizzArd	type ==> typo
12:16	AWizzArd	:)
12:42	AWizzArd	How can I make a private inner class and extend it from an existing one?
12:42	stuartsierra	In Clojure?
12:43	AWizzArd	yes
12:43	AWizzArd	proxy, right?
12:43	stuartsierra	inner classes don't really have any meaning in Clojure
12:43	stuartsierra	You can proxy almost any class.
12:43	AWizzArd	stuartsierra: please look at this example: http://www.rgagnon.com/javadetails/java-0538.html
12:44	stuartsierra	just proxy javax.mail.Authenticator
12:44	AWizzArd	oki good
12:50	AWizzArd	stuartsierra: and how can I make an instance of that proxy?
12:51	AWizzArd	in the example code the guy did Authenticator auth = new SMTPAuthenticator(); where SMTPAuthenticator was his private inner class that extended the Authenticator
12:51	AWizzArd	But I can't just call new on a proxy
12:53	Chousuke	you have a function that contains (proxy [Authenticator] [] ...)
12:54	Chousuke	and then just call the function whenever you need an instance
12:54	AWizzArd	ok, I see
13:58	stuartsierra	rhickey: I maven-ized your rdfm sources: http://github.com/stuartsierra/rdfm
14:04	rhickey	stuartsierra: what does that mean?
14:04	stuartsierra	I wrote a pom.xml with all the necessary dependencies.
14:05	rhickey	wow - does it really need all of those?
14:05	stuartsierra	Sesame is weird, it's broken up into lots of little modules. I haven't figured out if there's a cleaner way to depend on the whole thing.
14:07	rhickey	I know consumers of rdfm using Sesame might end up using a lot of it, but I've tried to minimize the use in the lib itself, in case people want to use with allegrograph or virtuoso probably won't need more than repository and model
14:08	stuartsierra	true
14:08	stuartsierra	I'll see if I can minimize it
14:08	rhickey	is there a reason to have src/main/clojure/ then org/clojure/rdfm.clj?
14:09	rhickey	is that a maven thing?
14:10	stuartsierra	It's the default maven directory layout, things are easier if you follow that.
14:10	technomancy	maven users generally get paid by the directory. =)
14:10	rhickey	ah
14:11	rhickey	silly me, I just put the deps in http://github.com/richhickey/rdfm/downloads
14:11	stuartsierra	There's a kind of logic to it, dividing up all your sources by type means you never need to filter on file names.
14:11	rhickey	stuartsierra: I'm fine with whatever is easy, just wondering what it will take to rearrange my repo
14:12	stuartsierra	Nothing much, you can just pull from me if you want.
14:12	stuartsierra	Just pushed a smaller pom.xml
14:13	stuartsierra	I only changed one line in rdfm.clj, commenting out (set! print-meta...)
14:15	stuartsierra	Copying jars around just got annoying, I'm trying hard to make Maven work.
14:15	rhickey	stuartsierra: did you get to look at the model? I dropped all used of bnodes, I'm kind of anti-bnode now. once an identity is in the rdf graph you can use rdfm/assoc/assoc/dissoc/dissoc (in transactions) to maintain it
14:17	rhickey	I have thoughts about being able to tie rdf and jms queue transactions to dosync
14:17	stuartsierra	I don't like bnodes either, but how do you avoid them?
14:17	rhickey	then you could dosync, with linked rdf/queue transactons, and on STM retries you'll get rollbacks, all commit together
14:18	rhickey	then you could dosync, with linked rdf/queue transactons, and on STM retries you'll get rollbacks, all commit together
14:19	rhickey	stuartsierra: I just never create bnodes. for this api the purpose is to rdf-persist Clojure data, so it's just a matter of choice
14:19	stuartsierra	Ok, that makes sense.
14:20	rhickey	plus, I can;t rely on bnodes being the determinant of whether something is 'owned/nested'
14:20	stuartsierra	what does owned/nested mean?
14:20	rhickey	finally, bnodes have startling existential semantics that few people using them are aware of
14:21	rhickey	when you store an unnamed composite as an attribute (a nested map/vector) they are considered 'part' of your document (for document style use). These would normally be things for which bnodes would be used, not addressed directly only as a subpart
14:22	rhickey	but storing nested as bnode doesn't imply bnode == nested
14:22	rhickey	so now there is a proper ns for nested collections
14:23	stuartsierra	ok, so for rdfm, bnodes DO imply nesting?
14:23	rhickey	when you store-root you get a top-level identity (UUID URI if you don't supply your own)
14:26	stuartsierra	ok
14:26	rhickey	stuartsierra: no, there are no more bnodes at all,
14:28	rhickey	nested aggregates are under the http://clojure.org/data/collection/ ns
14:28	rhickey	http://clojure.org/data/collection/vector# "http://clojure.org/data/collection/hash-map#
14:29	rhickey	uuid after the #
14:30	rhickey	so pull will grab nested by default, but not walk into other URIs
14:30	rhickey	the idea is inspired by CBD: http://www.w3.org/Submission/CBD/
14:31	rhickey	but pervasive use of bnodes in some graphs renders cdb tricky
14:31	rhickey	this way there is a clear document model - don't want ownership then store-root it separately
14:32	rhickey	still up in the air are true functional properties, I really want them
14:32	stuartsierra	OWL has functional properties, but not RDF alone.
14:33	rhickey	yeah OWL has FunctionalProperty but no triplestore has enforcement
14:34	rhickey	I could use that as a tag, but would need to preload and cache in order to avoid having to look up for every statement store
14:34	Chouser	ignore me if this is too off topic, but do you know of any revision control predicates for RDF?
14:34	rhickey	basically I need to know so I can restore a single-statement s p o as either o or #{o}
14:35	rhickey	Chouser: I once built a triplestore on relational that had full point-in-time snapshot capability
14:36	Chouser	so the snapshoting was outside the RDF graph?
14:36	rhickey	basically was not triples (none are) and had a version/deleted field in each statement
14:36	stuartsierra	Chouser: http://vocab.org/changeset/schema.html
14:40	Chouser	stuartsierra: ok, interesting. I wish google wave used rdf internally.
14:43	stuartsierra	rhickey: re restoring single statements, I don't think that's solvable right now. RDF is too vague about that.
14:52	rhickey	stuartsierra: well. if I or the user would tag those predicates as functional I could easily restore as single vs 1-item-set
14:53	rhickey	then {:a 1 :b #{2}} would round-trip =
14:53	rhickey	:a functional, :b not
14:54	stuartsierra	ok, just figured out how to dump the triples:
14:54	stuartsierra	(.exportStatements c nil nil nil false (org.openrdf.rio.turtle.TurtleWriter. out) (into-array org.openrdf.model.Resource []))
14:55	stuartsierra	If you want to round-trip, you might as well define RDFS Classes for each Clojure type.
14:56	rhickey	stuartsierra: I really want to use as little of rdf as possible. I want to leverage triplestores. RDF itself is another story
14:57	rhickey	the only reason I'd use owl:FunctionalProperty is it says what I want. I fully expect to pull partial graphs etc. I don't want an oodb
14:58	stuartsierra	hm, ok. Those predicates just look odd, like you're embedding type information in the URI.
14:58	rhickey	right now if you store :b #{2} you get back :b 2
14:59	stuartsierra	I'd prefer to store :b 2 and get back :b #{2}
14:59	rhickey	stuartsierra: I am, and yes. but the alternative is double lookup for everything and my data in your data
15:00	rhickey	stuartsierra: that's the easy way, but really, most application data is not multi-valued
15:00	stuartsierra	true
15:00	rhickey	I asked about multimaps here a while ago and got a bunch of - who cares? :)
15:01	stuartsierra	What's a multimap? Like {#{:a :b} #{:c :d}} ?
15:01	rhickey	I'd find it really arduous to have to deal with a ton of single-value sets
15:02	stuartsierra	That doesn't bother me so much, only because I realized that merging maps that might contain duplicate information, I ended up with lots of single-value sets anyway.
15:02	rhickey	stuartsierra: multimap is exactly what I'm doing with rdfm (and what rdf does) - you can consider rdf subjects + predicates multivalue maps
15:03	rhickey	stuartsierra: I think if you are working with pre-existing rdf data there is a completely different set of needs. In fact, AAA theory means you could always get another value for any predicate
15:04	stuartsierra	right
15:04	rhickey	this Clojure data model has a closed-world assumption
15:04	stuartsierra	ok
15:04	rhickey	I think it is a really interesting space, but triplestores have been dominated by rdf and semantic web
15:04	stuartsierra	got to go grab some lunch, back in a few
15:06	rhickey	hmmm--- should we use cgrand's parsely for cinc? - http://github.com/cgrand/parsley/blob/master/src/net/cgrand/parsley/demo.clj#L11-42
15:07	Chouser	Chousuke's got a reader mostly done. I haven't looked at it.
15:07	Chouser	ambiguous grammars. huh.
15:09	Chousuke	I should just find the time to make clojure actually use my reader and work out the bugs :P
15:10	Chousuke	but a reader based on a proper parser library might be better.
15:11	Chouser	I was thinking it might be nice to have a lib that converts a Compiler-produced AST to a clojure-collection AST
15:11	cgrand	rhickey: perfwise, I wouldn't recommend it. It's aim is to serve as the basis for the incremental parser in the Eclipse plugin. I think it has too much baggage to be used in lieu of a simple reader.
15:12	rhickey	cgrand: I'm sure not as fast as a reader, but incremental, recoverable parser is need for so many tools
15:13	Chouser	this would allow work on defining the cinc AST to proceed first (with immediate benefits for understanding current Compiler decisions ala expression-info) and allow java-emit code and cinc compiler work to proceed independently
15:14	Chouser	also could be used to compare results of cinc compiler with current compiler.
15:14	Chouser	the main drawback: it would all be throwaway code. :-/
15:15	Chouser	another benefit: more fun to write than performance-tuning finger trees
15:18	stuartsierra	Question about all the parsers/readers: why not just write a grammar?
15:20	rhickey	stuartsierra: for what, antlr?
15:20	stuartsierra	sure, or JavaCC
15:20	stuartsierra	antlr's easier
15:22	Chouser	we'd have to have all antlr in the clojure runtime then, right?
15:22	stuartsierra	yes, but it's not that big; if you can't bear the thought, use JavaCC
15:22	rhickey	stuartsierra: #1, it's another dep, #2, it's left-recursive
15:23	stuartsierra	Why is left-recursion a problem?
15:26	rhickey	http://code.google.com/p/clojure/source/browse/trunk/src/jvm/Reader.g?r=300
15:27	rhickey	I forget how far I got...
15:28	stuartsierra	ah, ok
15:28	rhickey	in the end, a lisp-style reader is so trivial
15:28	stuartsierra	true
15:29	stuartsierra	so why does everyone seem to want to rewrite it?
15:31	hamza	hey guys, i am trying to save a map to a file for some state saving, i am trying to use prn for this but i can't seem to find how should i direct prn to a file? doc says it outputs to out i am assuming it is console?
15:32	hiredman	out is a var
15:32	hiredman	,(doc out)
15:32	hiredman	:(
15:33	hamza	in my system it defaults to System/out. can i change it without messing the repl or is there another way to save a map?
15:34	hiredman	you use binding
15:34	stuartsierra	You can bind it. (binding [out (java.io.FileWriter. "/your/file")] ...)
15:35	hamza	thanks, am i on the correct route at using prn to save things to files, or is there a better approach?
15:35	stuartsierra	yes
15:35	stuartsierra	prn is good
15:37	hamza	one other thing how do i read it back?
15:37	stuartsierra	(read-string (slurp "/your/file"))
15:38	hamza	thanks, is there a limit on the size of the file for reading? that i should know about/
15:38	hamza	.
15:38	stuartsierra	Only the limit of memory in the JVM.
15:39	hamza	thanks a lot,
15:40	lambda-avenger	Are there any examples on using Java enums from clojure?
15:40	hiredman	,(doc out)
15:40	clojurebot	"; A java.io.Writer object representing standard output for print operations. Defaults to System/out"
15:41	stuartsierra	lambda-avenger: you can refer to an existing enum just a static field, ClassName/VALUE_NAME
15:41	stuartsierra	but you can't create new enum types
15:42	cschreiner	how can I change the bindings of out permantently?
15:42	hiredman	,(doc reductions)
15:42	clojurebot	"clojure.contrib.seq-utils/reductions;[[f coll] [f init coll]]; Returns a lazy seq of the intermediate values of the reduction (as per reduce) of coll by f, starting with init."
15:43	stuartsierra	cschreiner: not recommended, but (alter-var-root (var out) (fn [_] the-new-value))
15:43	lambda-avenger	Been trying that, but keep getting java.lang.Exception: Unable to find static field: OneStar in class jcolibri.test.recommenders.travelData.TravelDescription
15:43	cschreiner	stuartsierra: thx
15:44	hiredman	lambda-avenger: uh
15:45	hiredman	according to http://guru-games.org/projects/jcolibri/jcolibri2/doc/api/jcolibri/test/recommenders/travelData/TravelDescription.Seasons.html there is no enum constant with that name in that enum
15:46	lambda-avenger	That's a different enum. http://gaia.fdi.ucm.es/projects/jcolibri/jcolibri2/doc/api/jcolibri/test/recommenders/travelData/TravelDescription.AccommodationTypes.html
15:47	hiredman	well that is the enum you are looking for OneStar in
15:47	hiredman	according the exception you pasted
15:48	lambda-avenger	But both enums reside in the same class TravelDescription
15:48	hiredman	no
15:49	hiredman	oh
15:49	hiredman	are you sure that is the full exception message?
15:51	hiredman	jcolibri.test.recommenders.travelData.TravelDescription$AccommodationTypes/OneStar
15:51	lambda-avenger	That works, thanks hiredman.
15:51	clojurebot	hiredman is lazy
15:51	hiredman	clojurebot: thanks, jerk
15:51	clojurebot	Huh?
15:52	hiredman	clojurebot: you heard me!
15:52	clojurebot	hiredman: I'm just giving you a second chance
15:52	hiredman	clojurebot: why, I outta!
15:52	clojurebot	http://clojure.org/rationale
15:53	hiredman	clojurebot: brain?
15:53	clojurebot	brain dump is http://clj.thelastcitadel.com/clojurebot
15:59	lpetit	hi
16:03	cschreiner	the clojurebot is pretty cool
16:03	cschreiner	can clojure rule the world?
16:03	hiredman	clojurebot: well?
16:03	clojurebot	Excuse me?
16:04	cschreiner	clojurebot: can you rule the world?
16:04	clojurebot	what the world needs is more higher order functions
16:04	cschreiner	clojurebot: what is reality?
16:04	clojurebot	reality is an illusion which arises due to a lack of drugs
16:04	cschreiner	ok, I see
16:04	hiredman	:/
16:06	technomancy	hamza: you can use with-out; that encapsulates what you want
16:06	technomancy	~doc with-out
16:06	clojurebot	I don't understand.
16:06	technomancy	,doc with-out
16:06	clojurebot	java.lang.Exception: Can't take value of a macro: #'clojure.core/doc
16:06	technomancy	,(doc with-out)
16:06	clojurebot	No entiendo
16:06	hiredman	,(doc with-out-str)
16:06	clojurebot	"([& body]); Evaluates exprs in a context in which out is bound to a fresh StringWriter. Returns the string created by any nested printing calls."
16:06	technomancy	you think by now I'd get the hang of this
16:06	technomancy	yes, that
16:06	stegano	hi guys I am curious about clojure ... and by reading the brief description on the home page it seems the language is dynamic like Ruby .. and its a compiled language too ... so I am wondering does the compilation to bytecode happen at execution time or not ??
16:06	hiredman	stegano: depends
16:07	technomancy	stegano: Ruby is compiled and dynamic too (YARV/Rubinius)
16:07	stegano	hiredman: hmm ... could you elaborate onthis
16:07	dnolen	stegano: when you start up a Clojure REPL and evaluate forms they get compiled on the fly.
16:08	hiredman	you can take a .clj file and compile it to byte code a head of time
16:08	dnolen	you can also Ahead-Of-Time (AOT) compile files as well.
16:08	dnolen	stegano: Clojure is never interpreted.
16:08	hiredman	or you can just load the .clj file, and it will be compiled to bytecode then executed
16:08	cschreiner	,(doc union)
16:08	clojurebot	Excuse me?
16:09	hiredman	clojure.set/union
16:09	cschreiner	ah, thx
16:11	stegano	dnolen: so clojure REPL is like Scala's and AOT is also similar .... actually there is only AOT in clojure right?
16:11	stegano	i mean AOT compilation
16:12	Chouser	for some reason we use AOT to refer only to saving out .class files
16:12	hiredman	well, the other is sort of JIT to bytecode
16:13	hiredman	sort of
16:13	Chouser	Yeah, I suppose.
16:15	stegano	Chouser: so .clj i take it is the extension for clojure source file ... what I am trying to understand is when does JIT happen in clojure and when does AOT happen .... or is AOT always manual invoked ?
16:15	Chouser	AOT is manually invoked using the 'compile' fn.
16:15	Chouser	,(doc compile)
16:15	clojurebot	"([lib]); Compiles the namespace named by the symbol lib into a set of classfiles. The source for the lib must be in a proper classpath-relative directory. The output files will go into the directory specified by compile-path, and that directory too must be in the classpath."
16:17	hiredman	stegano: I wouldn't actually go around calling it the compile to byte code just before execution bit a JIT
16:17	hiredman	it is bound to be confused with the jvm's JIT to native code
16:19	stegano	hiredman: i agree it will be confusing ... so is there a term used in the clojure land to describe to compilation to bytecode .... and more importantly is the compilation to bytecode invoked from within the code ...... it seems it is using (doc compile) ... am I wrong ?
16:20	hiredman	compile is just for the AOT of time stuff
16:20	hiredman	which is somewhat exceptional
16:21	hiredman	mostly I just type stuff into the repl like (+ 1 2) and it gets compiled to bytecode and executed
16:22	stegano	hiredman: so compile is just for AOT ... which is manually invoked from within clojure code using (doc compile) ?? or is there a shell command to AOT compile clj sources
16:22	hiredman	there are a few ways you can do it
16:22	hiredman	~clojure-stub
16:22	clojurebot	clojure-stub is http://github.com/nakkaya/clojure-stub/tree/master
16:22	hiredman	is a stub project that uses ant to AOT compile clojure code
16:24	stegano	hiredman: cool thanx for letting me know about clojure-stub ..... so the dynamicity of clojure is from the fact that there is duck typing and the code doesn't need to compiled Ahead of Time ... so its almost interpreted in a way ??
16:24	hiredman	no
16:24	hiredman	it is definetely compiled
16:26	stegano	hiredman: ok only in REPL the clj source doesn't need to be compiled ahead of time ... in that way its like lisp/ruby/scala REPL .... but outside of REPL I assume clojure is like scala in that the source file need to be pre-compiled
16:26	hiredman	nope
16:27	stegano	hiredman: ok i am thoroughly confused :(
16:27	hiredman	~compile
16:27	clojurebot	the unit of compilation in clojure is the namespace. namespaces are compiled (not files). to compile a namspace the namespace needs to be on the classpath and so does ./classes/ (and the directory needs to exist) because clojure writes the class files to that directory. http://clojure.org/compilation
16:27	hiredman	the url there has a list of reasons why people might need to AOT compile their code
16:28	hiredman	besides that there isn't much of a reason
16:28	Chouser	you can think of it this way: every top-level expression (at the REPL or in a file) gets compiled to bytecode and then run by the JVM
16:28	hiredman	rlwrap java -server -Djava.security.manager -cp $CLASSPATH:./clojurebot/ clojure.main -i clojurebot/hiredman/clojurebot.clj -r
16:28	Chouser	it can also (by use of the 'compile' function) be saved to a .class file just before it's run by the JVM.
16:28	hiredman	is how I launch clojurebot, from a .clj file, no AOT compilation
16:30	drewr	is there something, in commons-httpclient perhaps, that will decode HTML?
16:30	stegano	clojurebot: so namespace can span multiple clj files and these files can be loaded in REPL shell or they can be executed outside of REPL .... in the latter style of execution ... won't the clj files need to be precompiled ??
16:30	drewr	I need "foo & bar" -> "foo & bar"
16:30	dnolen	stegano: AOT is all about deployment. Perhaps you just want to deploy a jar of compiled code. Perhaps you want fast start up time (say you have a _lot_ of clojure files). perhaps you running on a platform where compiling code on the fly is unrealistic (Google App Engine, Android)
16:31	hiredman	the repl is not anything special
16:31	hiredman	it is just a few clojure functions
16:32	drewr	ah, here we go
16:32	drewr	http://stackoverflow.com/questions/994331/java-how-to-decode-html-character-entities-in-java-like-httputility-htmldecode/994339#994339
16:32	stegano	hiredman: so basically clojure REPL is not much different from scala's REPL except that in clojure you can compile a namespace
16:32	stegano	hiredman: is that right ?
16:32	clojurebot	hiredman is an evil genius.
16:32	hiredman	drewr: http://gist.github.com/185550 is pretty useful
16:32	hiredman	clojurebot: knock it off
16:32	clojurebot	Huh?
16:33	hiredman	stegano: I don't know anything about scala's repl
16:34	hiredman	~scala ((x: Any, y: Any) => (f: Function2[Any, Any, Any]) => f(x, y))(1, 2)((x: Any, y: Any) => x)
16:34	clojurebot	Any = 1
16:35	stegano	you guys just drew circles around me and that too of parenthesis :) shame on you :)
16:35	stegano	just kidding
16:39	lpetit	Does anybody know if there's an automated way to migrate a google code project's wiki pages and issues to e.g. github ?
16:44	hiredman	there was an issue filed about it in the googlecode issue tracker
16:44	hiredman	I know clojure's issues where migrated by hand
16:45	lpetit	oh ok. I just have 30 bugs in clojuredev to be migrated to ccw, I guess I'll do that by hand too.
18:17	manic12	is it better to use slime for clojure, because I'm having a helluva time with enclojure?
18:22	ambient	use what feels best for you. dont fix what aint broken
18:24	manic12	yeah, but I want to learn clojure, I'm already good with common lisp
18:25	ambient	enclojure is good, i use it. it's great. use it
18:25	manic12	then please help me
18:25	ambient	i've found no problems with it
18:25	ambient	you're not presenting me with any problem
18:26	manic12	i'm on the #enclojure channel, can you talk to me there?
18:26	ambient	sorry, can't right now
18:26	manic12	can't talk or can't switch?
18:45	stegano	hi guys could you name some testing frameworks for clojure and webframeworks too please
18:46	Chousuke	clojure.test (only in git at the moment though) and compojure :P
19:33	crios	hello
19:34	crios	I'm a clojure newbe. Could anyone help me on an example of "clojure programming" book?
19:36	arbscht	crios: state your question and someone will help you if they can :)
19:37	crios	I cannot understand how the "parse" xml function is included into the "examples/tasklist.clj" example
19:38	crios	the example starts with a "(:use [clojure.contrib.duck-streams :only (reader)])"
19:38	crios	but does not contain (:use [clojure.xml :only (parse)])
19:39	crios	the function is then used in this way: (parse (InputSource. (reader (File. arg)))
19:39	crios	etc
19:41	crios	How is 'parse' imported? After two hours trying to understand I'm a bit puzzled :)
19:43	Chousuke	it might just be a mistake in the example :/
19:43	crios	here the code: http://pastebin.com/d28b74b0e
19:44	crios	no, it compiles with (compile 'examples.tasklist)
19:44	crios	(and that was also my first thougth :))
19:45	Chousuke	that uses clojure.xml/parse directly though. hm.
19:45	crios	I checked also the "clojure.contrib.duck-streams" library, but no 'parse' import, too
19:45	Chousuke	does it run as well? :/
19:46	Chousuke	just compiling it does not guarantee that it runs.
19:46	crios	@Chousuke: the (clojure.xml/parse is mine
19:46	crios	the original version is (parse
19:47	crios	And yes, it worked.
19:48	JAS415	parse is in clojure ns
19:48	Chousuke	you're not running it from the repl or anything?
19:48	Chousuke	,`parse
19:48	clojurebot	sandbox/parse
19:48	Chousuke	apparently not :/
19:48	JAS415	hmm
19:49	crios	here the original version: http://pastebin.com/d3bb9cfa2
19:49	crios	parse is into xml.clj , into clojure.jar
19:49	Chousuke	ah, duh.
19:49	Chousuke	it's not clojure.xml/parse at all
19:50	Chousuke	it's a method of the SAX parser object.
19:50	Chousuke	note the .. form on the previous line
19:51	JAS415	lol
19:51	Chousuke	it's like SAXParserFactory.newInstance().newSAXParser().parse(new InputSource( ...))
19:51	crios	so an instance method can start without a dot? I was expecting (.parse
19:51	Chousuke	crios: it's ..
19:52	Chousuke	crios: (.. foo bar (foo bar)) means foo.bar().foo(bar)
19:52	crios	Ah ok, I understand!
19:53	Chousuke	you might prefer -> to ..
19:53	crios	really puzzled , thank you Chousuke
19:53	Chousuke	,(-> "Hello" (.substring 2 5) .toUpperCase)
19:53	clojurebot	"LLO"
19:54	Chousuke	,(.. "Hello" (substring 2 5) toUpperCase)
19:54	clojurebot	"LLO"
19:54	Chousuke	,(-> "Hello" (subs 2 5) .toUpperCase); -> works with clojure functions too
19:54	clojurebot	"LLO"
19:55	Chousuke	.. is pretty much obsolete because of -> but it was there first.
19:55	crios	ah, never seen this notation : ->
19:55	crios	so -> is "deprecated" ?
19:55	Chousuke	neither is. -> is more powerful than ..
19:56	Chousuke	if anything, .. should be deprecated
19:56	crios	why more powerful?
19:56	clojurebot	http://clojure.org/rationale
19:56	Chousuke	crios: you can't mix clojure functions and java methods with ..
19:56	Chousuke	crios: it's strictly method-only
19:57	Chousuke	crios: whereas -> actually just transforms code like (-> foo .bar) to (.bar foo)
19:58	crios	so if (.. whatever (whatever ()) ) then 'whatever' can be just java method and never functions?
19:58	Chousuke	and further (-> foo (.bar zonk) clojurefn) becomes (-> (.bar foo zonk) clojurefn)
19:58	Chousuke	yeah
19:58	Chousuke	-> is a more general macro that just accidentally happens to do what .. does if you use it with the ".method" method notation
20:00	crios	ok, thank you, I'm still reading the book and have not yet seen -> (I hope it will be explained)
20:02	Chousuke	in short, -> does the following: 1) if the second argument is a symbol, wrap it in a list. otherwise, do nothing 2) take the first argument and insert it after the head of whatever results from step 1. 3) if there are more arguments, call -> on the result of step 2 and the remaining arguments; otherwise, the code generated is what step 2 produced.
20:03	Chousuke	it sounds complicated no matter how you explain it but if you try and experiment a bit you should see it's pretty useful
20:03	Chousuke	and rather simple, in the end :)
20:03	crios	(I'm copying you description, to study it carefully :)
20:04	crios	here where the author uses clojure.xml/parse: http://pastebin.com/dcf15462
20:06	crios	coming from java, it is a sort of challenge read a source code as a parser/tokenizer would do, in a lexical way
20:06	crios	in java you have just packages, and simple import stastement
20:08	crios	-> is a reader macro? should it be here :http://clojure.org/reader ?
20:08	Chousuke	nah, it's just a macro.
20:09	Chousuke	(doc ->)
20:09	clojurebot	"([x form] [x form & more]); Threads the expr through the forms. Inserts x as the second item in the first form, making a list of it if it is not a list already. If there are more forms, inserts the first form as the second item in second form, etc."
20:11	crios	also here http://clojure.org/API#toc35
20:11	Chousuke	the thing to remember with macros is that their arguments are not your program's values, but literally code.
20:13	Chousuke	so if you do (def foo (new SomeJavaClass)) and then do (-> foo .method .method2) you're not calling -> with the instance of SomeJavaClass as its parameter --- the parameter is the symbol foo
20:14	Chousuke	similarly, the .method and .method2 are also only symbols
20:15	Chousuke	the macro then does whatever it wants with these symbols, and outputs a data structure that (hopefully) is valid clojure code
20:15	Chousuke	and then the compiler compiles it.
20:17	Chousuke	this is one more thing that takes a while to sink in, but until it does you're free to consider macros magical. :P I know I used to.
20:18	crios	:)
20:19	crios	ah another question: what is the difference between (var and (resolve ?
20:19	crios	both return Var , if I understood correctly
20:20	Chousuke	,(var +)
20:20	clojurebot	#'clojure.core/+
20:20	Chousuke	,(resolve '+)
20:20	clojurebot	#'clojure.core/+
20:20	Chousuke	,(resolve 'foo)
20:20	clojurebot	nil
20:20	Chousuke	,(var foo)
20:20	clojurebot	java.lang.Exception: Unable to resolve var: foo in this context
20:20	Chousuke	var is also a special form
20:21	crios	,(var 'foo)
20:21	Chousuke	also hm
20:21	clojurebot	java.lang.ClassCastException: clojure.lang.Cons cannot be cast to clojure.lang.Symbol
20:22	Chousuke	heh, weird error messages
20:22	crios	quoting the symbol
20:22	hiredman	,(macroexpand 'foo)
20:22	clojurebot	foo
20:22	hiredman	bah
20:22	hiredman	var sees (quote foo)
20:22	Chousuke	crios: var doesn't evaluate its argument (it's a special form) so it doesn't need to be quoted
20:23	hiredman	,(macroexpand-1 'foo)
20:23	clojurebot	foo
20:23	Chousuke	crios: in fact, if you quote it, var sees the list (quote foo)
20:23	Chousuke	(macroexpand ''foo)
20:23	Chousuke	,(macroexpand ''foo)
20:23	clojurebot	(quote foo)
20:23	Chousuke	(macroexpand is not a macro)
20:23	crios	,(var (quote foo))
20:23	clojurebot	java.lang.ClassCastException: clojure.lang.PersistentList cannot be cast to clojure.lang.Symbol
20:24	Chousuke	hm.
20:24	Chousuke	details leaking out
20:24	Chousuke	apparently 'foo is not strictly equivalent to (quote foo)
20:25	Chousuke	it is as far as semantics are concerned though so never mind that
20:25	crios	anyway , the difference between (var and (resolve is just the error handling (exception versus nil) ?
20:25	Chousuke	well, resolve is a function
20:25	Chousuke	which is why you need to quote the argument, as it wants a symbol as a parameter
20:26	Chousuke	,(resolve (symbol "+")); or you can do this
20:26	clojurebot	#'clojure.core/+
20:26	Chousuke	also hm
20:26	Chousuke	,(resolve 'String)
20:26	clojurebot	java.lang.String
20:26	Chousuke	,(var String)
20:26	clojurebot	java.lang.Exception: Expecting var, but String is mapped to class java.lang.String
20:28	crios	it seems (var expects a real Var, while resolve a symbol ?
20:30	Chousuke	nah, Var works with symbols too
20:31	Chousuke	I can't actually tell the primary motivation for it though :/
20:31	Chousuke	I suppose resolve is runtime and var, being a special form, is compile-time?
20:31	crios	who knows :)
20:31	Chousuke	rhickey would :P
20:32	Chousuke	oh well, read the docs for the special forms
20:32	hiredman	~def resolve
20:32	Chousuke	I'll get some sleep.
20:34	crios2	here I am
20:34	crios2	after a firefox crash
20:34	Chousuke	:/
20:35	crios2	here don't see the history
20:35	crios2	you was giving me the link http://github.com/richhickey/clojure/blob/e35c4688f30a542d3585e72cfe9bc66936ca5afe/src/clj/clojure/core.clj#L2629
20:35	Chousuke	nothing of value was said after that
20:36	crios2	ok
20:37	crios2	mm still don't see any real difference between var and resolve...
20:38	crios2	at last at 2:40 a.m. ! :D
20:39	Chousuke	well the fundamental difference still is that var is a special form and resolve is not.
20:40	crios2	ok
20:41	crios2	see you, good night and thank you
20:41	crios2	ciao
21:04	manic12	how do I get enclojure project repl to require my libs when it starts?
21:41	JAS415	what type of stuff do people use as database backends with clojure?
21:58	Chouser	JAS415: rhickey's working hard to get RDF triple stores to behave well in that capacity.
22:04	JAS415	cool
22:04	JAS415	now i just have to figure out what rdf triple is
22:05	JAS415	oo
22:06	JAS415	is like graph theory
22:06	Chouser	otherwise, regular java stuff -- jdbc sql, tokyo cabinet, etc.
22:08	JAS415	for anyone else for whom that went whoosh http://www.robertprice.co.uk/robblog/archive/2004/10/What_Is_An_RDF_Triple_.shtml
22:10	hiredman	~google rdf prolog
22:10	clojurebot	First, out of 29700 results is:
22:10	clojurebot	XML.com: An Introduction to Prolog and RDF
22:10	clojurebot	http://www.xml.com/pub/a/2001/04/25/prologrdf/index.html
22:10	JAS415	if I use tokyo cabinet in a desktop application (presumably by using the java library) will i have to GPL (LGPL?) the entire project?
22:10	hiredman	kind of a neat idea
22:16	JAS415	prolog is a pretty nice query language
22:16	JAS415	my minimal experience with sql involves headache
22:22	manic12	is there a way to import all the class names from a java package?
22:32	JAS415	i think there isn't
22:40	manic12	I must be trying to swim against the current
22:42	ambient	autoimports might be a cool IDE feature, because nothing seems to start with a capital letter in clojure :)
22:44	hiredman	eh? what does that have to do with aynthing?
22:46	ambient	you could type class names and automatically import them if they were found in the libs because they're capitalized