#clojure – 2009-07-15

2009-07-15

00:02	grrrt	how can you test if a name is a function? I guess isa? or instance? wouldn't work here?
00:04	gnuvince	grrrt: fn? and ifn? come to mind
00:04	gnuvince	,(fn? map)
00:04	clojurebot	true
00:04	grrrt	ahh doh!
00:04	grrrt	sigh, brain has left the office for the day :)
00:04	gnuvince	,[(fn? {}) (ifn? {})]
00:04	clojurebot	[false true]
00:04	grrrt	cheers
00:05	gnuvince	np
00:13	arohner	does anyone have experience running a profiler on clojure code in OSX?
00:13	arohner	or linux. but eclipse's TPTP is not working for me
02:29	Jomyoot	Is there example of how to structure clojure into different source files?
02:29	Jomyoot	name spaces and etc?
02:29	Jomyoot	basically a simple project structure
02:29	Jomyoot	i so far have used clojure as glue code. so all in one file
03:25	ataggart	very loosely speaking, one clj file for a namespace
04:54	Jomyoot	should they use or require each other?
05:05	AWizzArd	depends on how you want to use them
05:06	AWizzArd	both are valid options
05:06	AWizzArd	I use 60% and require 40%
05:39	Jomyoot	is there a guilde or tutorial for this?
05:50	ataggart	with require you still need to use a namespace (or namespace aliias). with use you don't need to prefix everythign with a namespace
05:50	ataggart	it's style prefernce more than anything
06:03	Jomyoot_	do i put deeper name spaces into deeper folders?
06:04	Jomyoot_	or throw all files into same folder
06:04	Jomyoot_	does java style folder/package mapping still work here?
06:06	jdz	the Java style hierarchical file/namespace relation remains
06:06	jdz	http://clojure.org/libs
06:08	Jomyoot_	any idea when cascade will be available?
06:09	jdz	what's cascade?
06:11	Jomyoot_	something tapestry guy said he would make
06:11	Jomyoot_	for clojure
06:11	Jomyoot_	that's all i know
06:11	Chousuke	Jomyoot_: you can also split a namespace into multiple files by having the "main" file use 'load to "include" other files
06:11	Jomyoot_	i don't even know if tapestry is popular
06:13	Jomyoot_	:use com.test.me.ns would that go look for the com/test/me/ns.clj file? assuming that it's all source file
06:13	Chousuke	yeah.
06:14	Chousuke	see (doc ns) and (doc require) at least.
06:14	Chousuke	the ns documentation is a bit scattered
07:36	Neun	hello, why does this not work: (eval (list #(%) "foo"))
07:36	Neun	why do I have to quote the function?
07:38	cemerick	Neun: is foo the function you're trying to invoke?
07:39	Neun	I tried this (map (comp eval list) list-of-functions list-of-elemts)
07:40	Neun	this works though: (map #(%1 %2) list-of-functions list-of-elements)
07:40	cemerick	eval is unnecessary unless you've got symbols, etc., as opposed to actual functions
07:41	cemerick	e.g.:
07:41	cemerick	,(eval '(+ 5 6))
07:41	clojurebot	DENIED
07:41	cemerick	bah
07:41	Neun	I see
07:41	cemerick	anyway, that would return 11, but clearly, you just want to invoke a fn directly:
07:42	cemerick	,(+ 5 6)
07:42	clojurebot	11
07:42	jdz	Neun: would just plain (map apply list-of-functions list-of-elements) not work?
07:42	Neun	jdz: no, apply needs a vector of arguments
07:43	jdz	no, just a sequence
07:43	cemerick	Neun: not so:
07:43	jdz	well, not really
07:43	cemerick	,(apply + (list 5 6))
07:43	clojurebot	11
07:43	jdz	the last argument should be a sequnce
07:43	cemerick	right
07:43	cemerick	,(apply + 14 (list 5 6))
07:43	clojurebot	25
07:44	jdz	,(apply + 42)
07:44	clojurebot	java.lang.IllegalArgumentException: Don't know how to create ISeq from: Integer
07:47	Jomyoot	can (def x (ref (hash-map)) bedefined using (let) as well?
07:47	jdz	let creates bindings in it's scope. when the scope is gone, so are the bindings.
07:49	cemerick	Jomyoot: you can certainly use let to perform some initial computation, and use the result as the value of the new def binding: (def x (let [foo ... bar ...] (ref {baz (some-fn foo bar)})))
07:59	rottcodd	is there a way to call private functions in another namespace?
07:59	cemerick	rottcodd: (#'some.other.ns/fn-name ...)
08:00	cemerick	#'foo returns the var named by foo
08:00	Chousuke	and var just happens to delegate to its value if it appears in operator position :P
08:01	cemerick	I think that was a stroke of genius. Much nicer than other lisps where you really had to be conscious of that sort of thing.
08:03	rottcodd	cemerick: thanks
08:10	rhickey	did anyone ever do a reasonable with-captured-bindings macro?
08:13	cemerick	ach, I always get tripped up by the order of fns to comp
08:14	rhickey	(foo (bar (baz ... -> (comp foo bar baz)
08:14	rhickey	i.e. comp just removes some parens
08:15	cemerick	rhickey: yeah, I just happen to use -> more often, which applies in the reverse order
08:15	cemerick	comp is more consistent with mathematical notation, too, so this is really just a mental problem on my part
08:15	rhickey	I have to think twice sometimes too :)
08:17	rhickey	I really want to get a pipe macro in place, to further confuse things :), like -> but puts arg at end. We've discussed before, just need a name
08:18	rhickey	saw an F# presentation where they did everything with the :> operator, made people very comfortable
08:18	cemerick	heh. I have no idea what :> would mean.
08:18	rhickey	sorry, \|> operator
08:18	cemerick	yeah, that doesn't ring any bells, either :-)
08:19	Chouser	$ means end-of-the-thing in regex and sh
08:19	rhickey	right, I'm not advocating \|>, but it had the same concept as pipe, put arg at end, except you have to keep repeating it
08:19	cemerick	ah
08:20	rhickey	we haven't used $ or \| yet, probably not worth it for this
08:20	rhickey	-<, <-
08:20	Chouser	($-> coll (map foo) (filter bar))
08:20	cemerick	well, I generally try to avoid shell scripting, so #(-> % .. .. ..) and comp are good enough for me :-)
08:21	rhickey	cemerick: really, you use -> and wouldn't use (pipe xs (map f) (filter p) (reduce op)) ?
08:22	Chouser	One of the first clojure macros I ever wrote was called >>_
08:22	Chouser	(>>_ coll (map foo _) (filter bar _))
08:22	rhickey	for pipe?
08:23	rhickey	funny I would have gone the other way <<
08:23	rhickey	maybe not
08:23	Chouser	it's going the same way as ->
08:23	rhickey	well, it's generally useful, and should be standard
08:24	Chouser	yeah, I used >>_ once or twice early on, but being non-standard makes it tiring to communitcate with others
08:24	rhickey	Chouser: yes, in some sense (calls) but not others (args)
08:24	rhickey	Chouser: especially with a name like >>_ :)
08:24	cemerick	rhickey: Not sure I'd use it, at least until I'd had a chance to internalize it. -> is very intuitive for me, but so far, I'm feeling like I'd end up having to read the docs on pipe when I end up reading code later on.
08:24	Chouser	hmph
08:25	cemerick	Stuff like that changes fast, though.
08:25	Neun	jdz: maybe I could write (map apply seq-of-functions (map list (seq-of-values)))
08:25	wlr	what's wrong with calling it just, er, pipe?
08:26	cemerick	FWIW, I use -> most often for simple navigation of data structures (-> foo :key deref seq last), etc.
08:26	rhickey	wlr: nothing, except for the other meaning of pipe (data structure, IO channel)
08:26	rhickey	cemerick: that's its intended use for sure
08:26	jdz	Neun: that should work.
08:27	rhickey	wlr: one reason -> isn't called 'thread'
08:27	cemerick	honestly, I'd be very worried if I were regularly mapping and filtering my way through things. Linear time bounds aren't nearly good enough. :-)
08:27	jdz	Neun: despite the fact that i don't like how it looks :/
08:28	Neun	jdz: yes, there should be something better/cleaner
08:28	rhickey	all of the seq fns are set up for pipe
08:28	wlr	rhickey: okay, competing concepts. thanks.
08:29	rhickey	anyway, we've got -<, <-, >>_, $-> - any others?
08:29	rhickey	->>
08:30	jdz	=>
08:30	Chouser	--> <--
08:30	jdz	==>
08:30	cemerick	<- is the most intuitive of them all, at least with respect to ->
08:30	jdz	^.^
08:30	jdz	but that's taken by meta
08:30	jdz	\m/
08:31	jdz	>.>
08:31	rhickey	I think Clojure datalog lib is using <- ?
08:32	cemerick	shouldn't it be (some-fn-name (filter f) (map f2) coll), though? By that I mean, shouldn't the collection be the last arg to the fn if it's proceeding right to left?
08:33	Chouser	but it's not proceeding right to left
08:33	Chouser	that's why the left-pointing things may not be appropriate
08:33	cemerick	ah-ha -- that's what I get for reading a random group posting on "pipe"
08:33	Chouser	(map f2 (filter f coll))
08:34	rhickey	it's kind of imperative, take xs, map it, filter it, reduce it ...
08:35	rhickey	In the F# demo it made people comfortable to see code that looked like "do this, do that", but was actually functional
08:36	rhickey	I'm now with Chouser that call order dominates the sense of order, not arg order
08:36	rhickey	so ->> or --> working best right now
08:37	Chouser	two > certainly stands out more than two -
08:37	Chouser	-=>
08:37	rhickey	yup
08:37	Chouser	->*
08:37	rhickey	= and > makes one think numbers
08:37	Chouser	>-
08:38	Chouser	>>-
08:38	rhickey	Chouser: documenting the path to >>_, eh :)
08:38	Chouser	:-)
08:38	cemerick	multiple >'s make me think of bit-shifts
08:39	Chouser	>--
08:39	rhickey	cemerick: me too, but ->> still seems like an arrow to me
08:39	Chouser	(>-- coll (filter x) (map y))
08:39	rhickey	which is kind of nice in being able to call them the two arrow ops
08:40	rhickey	arrow threads and double arrow pipes
08:40	rhickey	through a series of calls
08:42	cemerick	of course, there's the inevitable clojure impl of haskell arrows :-P
09:01	weissj	is there a particular reason why there's no builtin function called != ? that just does (not (= a b))
09:02	Chousuke	there's not=
09:02	cemerick	,(doc not=)
09:02	clojurebot	"([x] [x y] [x y & more]); Same as (not (= obj1 obj2))"
09:02	weissj	ah
09:02	cemerick	hrm, odd irc latency
09:02	weissj	would never have thought to look for that. :)
09:03	Chousuke	! carries the "side-effect!" meaning
09:03	weissj	Chousuke: even when the ! is at the beginning?
09:03	cemerick	I would have exempted it for !=, but oh well
09:04	cemerick	that's one of the advantages of having a BDFL (or similar), as opposed to cargo-cult design.
09:06	Jomyoot	do I have to both (require) and (refer) a namespace in another file?
09:06	jdz	or just use?
09:06	weissj	cemerick: what are bfdl and cargo-cult designs
09:07	cemerick	Jomyoot: yeah, just use use, or, require with an :as name: (require [some.ns.util :as util]), and then access some.ns.util's fns with util/fn-name
09:08	Chousuke	require needs its argument quoted though :)
09:08	Chousuke	or you can use the ns macro
09:09	Jomyoot	So (refer) without (require) does not work?
09:09	Chousuke	I've never used refer directly :/
09:10	jdz	refer with require is called 'use', as far as i understand
09:10	cemerick	weissj: http://en.wikipedia.org/wiki/BDFL -- by cargo-cult, I meant a bikeshed-susceptible design process (http://bikeshed.com/)
09:10	jdz	and refer does work without require. see the documentation what refer does...
09:11	Jomyoot	I get java.lang.ClassNotFoundException: com.atcloud.build-tags-hash-map
09:12	Jomyoot	I have (ns com.atcloud
09:12	Jomyoot	(:use [clojure.contrib.sql]))
09:12	Jomyoot	and (defn build-tags-hash-map [db] in the other file
09:12	jdz	do you have a file com/atcloud/build_tags_hash_map.clj in your classpath?
09:13	Jomyoot	i am idiot
09:13	Jomyoot	i am supposed to use /
09:13	Jomyoot	rather than . i think
09:15	weissj	is it possible that a future version of clojure will allow you to have a function call earlier in the file than its definition? or is there something too inherent in the language that disallows this?
09:15	weissj	it's not a huge deal, but it tends to make a file harder to read (the higher level more 'important' stuff is at the bottom)
09:16	cemerick	weissj: I think rhickey has said that it's possible that forward declarations could eventually be handled automatically
09:16	weissj	cemerick: cool
09:16	cemerick	until then, you can use declare to create those (undefined) vars, and then define them later in the file
09:17	weissj	cemerick: functions too?
09:17	cemerick	especially functions
09:17	cemerick	IME, anyway
09:17	weissj	hm, i'm not sure if that makes things better or worse :)
09:17	cemerick	well, it lets you structure your code how you want, anyway
09:18	weissj	cemerick: yeah, but you still have declarations at the top
09:18	cemerick	it generally doesn't happen that much, at least to me
09:18	cemerick	shrug
09:18	weissj	oh i see you can declare them all at once? nice
09:18	weissj	ie (declare a b c d)
09:19	rhickey	cemerick: I don't know that I said that - it would be a change to the compilation model (from the equivalent of streaming the same commands into a repl), and would require the introduction of some notion of compilation unit, issues with macros etc
09:19	rottcodd	should I use var or var for variable names?
09:19	jdz	rottcodd: "variables" is a very stretched term
09:20	rhickey	rottcodd: var only if you intend to dynamically rebind them
09:20	cemerick	rhickey: it was a long time ago (probably two April's ago or so), when I had the same question as weissj. I wouldn't be surprised if things have changed since then that would make it less feasible.
09:20	cemerick	regardless, it's surely a lot of work for a very small gain, IMO
09:20	rhickey	cemerick: it is certainly possible, but a lot of work for a very minor feature IMO
09:20	rhickey	heh
09:20	Chouser	I find code easier to read when I know where to find definitions, that is "above here". Declaring things out of order doesn't seem like an improvment to me.
09:22	weissj	Chouser: yeah i don't think it's a big deal either, i am just used to java where i put all my private and protected methods at the bottom
09:22	rhickey	what old time Lispers really want is not whole-file resolution, but simply the ability to compile with unresolved names and get runtime errors
09:22	cemerick	old-time common lispers, of course. The current situation in clojure is exactly like the schemes I remember.
09:23	rhickey	cemerick: yes, CL
09:24	rhickey	there's the whole 'define your program in the debugger' thing
09:24	cemerick	rhickey: did you notice the type hinting that C. Nutter is adding to JRuby?
09:24	rhickey	cemerick: link?
09:26	cemerick	rhickey: http://twitter.com/headius/status/2639903017 http://twitter.com/headius/status/2640249841 http://twitter.com/headius/status/2640406401
09:28	rhickey	cemerick: java with 'end' ?
09:28	cemerick	ouch :-)
09:29	rhickey	I've said the same thing as far as Clojure becoming Java with parens
09:29	rhickey	what's the point?
09:29	cemerick	either are surely better than Java -- if the hints are just there to keep the reflector away, then all's well
09:31	cemerick	rhickey: it's telling that, honestly, most devs don't need much more than Java -- so, giving them the opportunity to write java-ish things in one's language makes adoption possible, anyway. And not ensuring smooth interop along all possible axes makes widespread adoption simply impossible.
09:31	rhickey	cemerick: I'm not sure, vs a Java stub and a simple way to reach more involved logic in the preferred lang. The cost is bringin in all the Java cruft into your lang, protected etc
09:34	cemerick	rhickey: Oh, I agree wholeheartedly, but then, I'm not involved in building or using a language for the masses.
09:34	rhickey	Have you ever seen LinJ?
09:34	rhickey	seems to have disappeared, but it was a lisp that generated idiomatic Java
09:35	rhickey	was weighed down, IMO, by the need to support all Javaisms
09:36	cemerick	its page on cl-user.net has a pretty meager example, but yeah, I can definitely see how dragging all that cruft along would make a lot of things painful
09:36	weissj	if I have a java method i want to call that can either return a value or throw an exception, and i want to catch the exception, or store the return val in a variable, how do i do this? declare the var as nil first?
09:36	rhickey	after all, if a lang Y is to support all constructs of another lang X, is it not inherently going to be more complex than X?
09:36	cemerick	type-hinting is pretty painful as it is, but it's certainly necessary
09:37	Chousuke	weissj: wrap the java method call in a function
09:37	cemerick	(although I wonder if the JIT in JDK 7 with all of its reflection-inlining, etc would optimize a reflective call to a regular method invocation given enough heat)
09:37	Chouser	weissj: (let [foo (try (foo-fn) (catch Exception e "error-val"))] ...)
09:38	weissj	Chouser: i see thanks
09:38	Chouser	that is, the final value of the catch block is what 'try' returns on the exception case
09:39	weissj	Chouser: yeah in my case i'm later checking for nil, so i'll have the exception clause return nil. that'll do it!
09:41	Jomyoot	is lisp code supposed to be more managable?
09:41	Jomyoot	than JAVA?
09:42	Jomyoot	once you have lots of it?
09:42	rhickey	so, last call, I'm thinking about calling 'pipe' ->>
09:43	Chousuke	Jomyoot: that probably depends on how good you're at writing manageable lisp code :)
09:44	Chousuke	Jomyoot: But lisp has more powerful tools for abstraction than java IMO, so I'd say yes.
09:45	cemerick	If you know what you're doing, there's amazing power in a good lisp. If you're not a good programmer, then you'll be hopelessly lost.
09:46	cemerick	I'm a little of both, but I've aspirations. :-)
09:51	weissj	is there a builtin function to execute a command on the command line (perhaps via java's Runtime/Process/execute api)
09:53	Jomyoot	so using .java stuff does break immutablity
09:53	weissj	clojure.contrib.shell-out/sh - found it. doc search on execute found nothing, but 'exec' found this
09:53	Jomyoot	i can modify their state without dosync
09:54	yason	Hmmm, was there a byte stream as a lazy sequence akin to line-seq ?
09:54	cemerick	Jomyoot: you can break immutability in a variety of ways if you're really motivated and your data structures allow it.
09:55	Jomyoot	what's the point of dosync when it's so easy to break immutability when using java objects
09:56	Chousuke	the point is that when you do use the immutable data structures, it allows for easy concurrency
09:56	Chousuke	Clojure does not force immutability on you. It just gets harder and harder to keep your program working the more mutability you introduce
09:57	cemerick	it's pretty difficult to introduce mutability to begin with, if you stay within clojure.
09:57	Chousuke	mutability support is pretty much an interop thing.
09:57	Jomyoot	it is hard to write Clojure without using java interop though
09:58	cemerick	Jomyoot: a corollary would be, "what's the point of garbage collection and memory protection in Java if it's so easy to segfault when you call into native methods?"
09:58	yason	Jomyoot: depends. I don't know Java much so I tend to steer away from any Java interop automatically
09:58	Chousuke	Hmm, perhaps.
09:58	Jomyoot	i get your point
09:58	cemerick	Jomyoot: Depends on your domain. I touch java very rarely.
09:58	yason	Jomyoot: I just wrap the most essential java stuff to get my stuff running (file i/o or GUI stuff) and stay with Clojure then
09:59	Chousuke	proper use of java interop is to keep it isolate from pure, functional clojure logic :)
09:59	Chousuke	isolated*
09:59	yason	Chousuke: that's what I was trying to say, with too many copies of "stuff" :D
10:00	Chousuke	of course, some java stuff is "immutable" as well, like strings, and thus not a problem.
10:01	Chousuke	It seems that arrays are the worst troublemakers :/
10:35	Jomyoot	Is emacs still pretty as IDE for Clojure?
10:38	weissj	anybody here known about ant tasks with lancet? (lancet/echo {:message "hi" :level "warning"}) gives java.lang.ClassCastException: Cannot cast java.lang.String to org.apache.tools.ant.taskdefs.Echo$EchoLevel
10:39	weissj	ant actually takes a string for :level, but here it seems to insist on an internal class called "EchoLevel"
10:39	shoover	Jomyoot: I'm not sure anyone has ever accused emacs of being pretty, for clojure or otherwise
10:39	shoover	useful, sure
10:42	Jomyoot	What is equivalence of simple hash in Ruby like this { :a => 1, :b => 2, :c => 3} is that HashMap in Clojure then?
10:43	Chouser	Jomyoot: {:a 1, :b 2, :c 3} is a map in Clojure
10:44	scgilardi	Jomyoot: and literal maps are hashmaps
10:45	Jomyoot	is 'a equivalence of :a in ruby?
10:46	arbscht	it's probably not wise to think in terms of direct equivalents
10:46	liebke	jomyoot, :a in ruby is equivalent to :a in Clojure
11:00	weissj	once i delete a function definition in a file, and load it into the repl, how do i remove the binding from the repl?
11:01	weissj	do i have to restart the repl?
11:01	weissj	(in other words i remove the function def 'myfunc' but the repl still sees it as defined and I don't want it to be)
11:01	Chousuke	you can either redefine the var to nil or something or use ns-unmap
11:02	Chousuke	it's pretty simple to write a function that "cleans out" a namespace
11:04	weissj	ok, i think i got that
11:05	weissj	what's wrong with (ns myns (use lancet (:as 'ant)))
11:05	weissj	java.lang.IllegalArgumentException: No value supplied for key: true (jonSuite.clj:1)
11:06	Chouser	(ns myns (:use [lancet :as ant]))
11:06	Chouser	except lancet probably needs to be longer
11:07	weissj	longer?
11:07	Chouser	should be the fully-qualified namespace name
11:07	Chouser	Halloway didn't call it just "lancet", did he?
11:07	scgilardi	and :as is more often associated with :require. with use, you're bringing all of lancet's names into the current namespace and then also allowing prefixing them with ant/
11:07	Chouser	good point!
11:08	Chouser	(ns myns (:use [lancet :as ant :only []]))
11:08	weissj	wait, i just want to refer to functions in lancet with the name ant instead
11:08	weissj	not also bring in everything into my own ns
11:08	Chouser	right.
11:08	Chouser	so :only []
11:08	weissj	ok
11:09	scgilardi	chouser's most recent example is how I would write that
11:09	Chouser	or you could use 'require' instead, but these days I don't usually recommend that
11:09	Chouser	I'm still hoping to see those two merged at some point
11:09	scgilardi	me too
11:11	cemerick	Chouser: you don't like require + :as?
11:12	Chouser	cemerick: it's fine until you decide there's one var you want to refer in
11:12	Chouser	so you had (:require [fully.foo :as foo])
11:12	Chouser	and now you have to change it to (:use [fully.foo :as foo :only [bar]])
11:13	weissj	Chouser: halloway did just call it 'lancet', btw
11:13	cemerick	so you prefer :use + :as + :only?
11:14	scgilardi	did we come up with any downsides to (:use fully.foo :as foo) implying :only [] unless explicitly overridden?
11:14	Chouser	cemerick: at least it's more consistent -- that way I don't end up with a block of :requires and a block of :uses and have to reorder things based on which ones need an :only
11:15	cemerick	yeah, that's a point
11:15	Chouser	scgilardi: breaking change is a downside
11:15	Chousuke	Chouser: couldn't you add a :refer after the require?
11:15	cemerick	scgilardi: as long as there is an escape hatch to get full use (a wildcard :only, essentially). I don't do that very often at all, but when I do, it's pretty necessary to retain sanity.
11:16	Chouser	Chousuke: is :refer supported by something?
11:16	scgilardi	cemerick: the escape hatch is :exclude []
11:16	cemerick	ok :-)
11:16	Chousuke	(ns something (:require [foo.bar :as foo]) (:refer foo.bar :only [some stuff here]))
11:16	Chousuke	Chouser: the ns macro?
11:16	Chouser	Chousuke: ah. I guess that might work, though 'ns' doesn't document it.
11:17	Chouser	I'd rather have the namespace listed once anyway.
11:17	Chouser	Chousuke: is there something wrong with :use + :only ?
11:17	Chousuke	Chouser: not really.
11:17	Chousuke	I guess it's a matter of preference
11:18	scgilardi	chouser: I find it a little ugly (though I still use it). It's like explicitly passing nil as an argument to a function. It kinda feels like it would be nicer if you didn't have to.
11:18	Chousuke	I guess the combined effect of :as and :only is a bit confusing, too
11:18	Chouser	scgilardi: yes!
11:19	Chousuke	you wouldn't expect the entire namespace to be available through the :as alias either.
11:19	Chouser	scgilardi: I find it ugly, but less painful than mixing both :use and :require in random ways in the same ns form
11:19	Chousuke	I wonder if ns actually does support :refer
11:19	Chouser	Chousuke: good point. maybe :only is misnamed for :use.
11:19	Chousuke	(doc refer) ; refers to it though :P
11:19	clojurebot	"([ns-sym & filters]); refers to all public vars of ns, subject to filters. filters can include at most one each of: :exclude list-of-symbols :only list-of-symbols :rename map-of-fromsymbol-tosymbol For each public interned var in the namespace named by the symbol, adds a mapping from the name of the var to the var to the current namespace. Throws an exception if name is already mapped to something else in the current nam
11:20	Chousuke	damn, too lon
11:20	Chousuke	g
11:20	Chouser	Chousuke: ns macro currently just maps the keywords (like :use and :require) to core function names, and calls them.
11:20	scgilardi	chouser: exactly right. I think the combination of :use and :as as we have things now is just an attractive hazard. Better replaced by useful functionality.
11:20	Chousuke	oh wait.
11:20	Chousuke	refer actually refers to :use, not :refer
11:21	Chousuke	hmm...
11:25	Chouser	so the least-breaking way forward would be to introduce a new word and give it the semantics we now know we want
11:25	Chouser	and deprecate :use and :require
11:25	scgilardi	chouser: I think Rich also had a notion of "default aliases" at one point. Removing :require and replacing it with :use :as would tend to thwart that.
11:26	Chouser	but using up another word has drawbacks too
11:26	Chousuke	Chouser: :assimilate? :)
11:26	Chouser	scgilardi: hm... maybe.
11:26	Chouser	:demand
11:26	Chouser	:-P
11:26	scgilardi	:depend
11:26	Chouser	actually -- hm. :require doesn't do anything bad, it's just missing features. Maybe that's the way forward.
11:27	scgilardi	what's it missing?
11:27	Chouser	perhaps we could add :refer and support for default aliases to :require
11:27	Chouser	then deprecate :use
11:33	scgilardi	as a detail of the current implementation (:require [clojure.contrib.sql :use true]) is exactly equivalent to (:use clojure.contrib.sql).
11:34	cemerick	oh, poor Stuart :-)
11:34	Chouser	oh, does :only work with :require?
11:35	scgilardi	only when accompanied by ":use true" (but that could be changed pretty easily, I think)
11:36	Chouser	oh, I see.
11:36	scgilardi	sounds pretty nice... add support for the refer options to :require and have them imply :use true (effectively)
11:37	Chouser	probably still need something that means :exclude, or at least :exclude []
11:38	Chouser	so as to enable our lazy brethren
11:38	Chouser	:refer-all-because-i-care-more-about-myself-than-my-readers
11:39	cemerick	Chouser: there are good reasons, aside from sloth
11:39	Chouser	cemerick: really?
11:39	Chouser	in cases where :as z or something wouldn't suffice?
11:40	cemerick	well, a throwaway :as name is just noise.
11:40	cemerick	I use use in conjunction with two namespaces that provide a pile of utility fns that we use throughout our codebase.
11:42	cemerick	e.g. stuff that, in our domain, we'd be perfectly happy if it happened to be defined in clojure.core (but obviously won't ever, and shouldn't be)
11:44	Chouser	hm
11:44	Chouser	ok, would you buy :refer :all ?
11:45	cemerick	what, (:require [foo.bar :refer :all])?
11:45	Chouser	yeah
11:45	cemerick	fine by me
11:46	cemerick	It's definitely a corner case, so I'm happy to accept a syntactic compromise in order to make everything else simpler.
11:50	scgilardi	:exclude is one of the refer options to support. We could add :refer :all as sugar for :exclude [], but we would already have the capability it provides.
11:51	scgilardi	the full list is :exclude, :only, and :rename
11:52	Chouser	but if :only is renamed to :refer (which I like very much) that raises the question of what :exclude and :rename should be called
11:52	Chouser	:refer-all-but for :exclude?
11:53	scgilardi	I think :only :exclude and :rename fit just as nicely with the word "require" as they do with the word "refer". Why rename :only to :refer?
11:55	Chouser	because require is a verb whose subject is the lib. "only" doesn't modify the lib, but something else, so it seems a poor fit to me. "refer" is a verb matching the core fn, so seems a natural choice.
11:56	duck1123	I always mess up :exclude as :except
11:58	scgilardi	I see it as "require this collection of stuff" (which is the lib). The modifiers let us optionally tailor which pieces of the collection we also bring into the namespace. I do see your point though, we are pulling in the entire lib either way and these options are about how that impacts the current namespace.
11:59	Chouser	on the other hand I care so much less about the name than the functionality. :-)
12:02	scgilardi	with either the current or the new names, this would be an easy change to get right in the implementation and would strictly add capability to require that nobody is using currently. it would leave us free to deprecate :use.
12:08	weissj	if i want to create a java object, call a setter on that object, then return the object, do i need a var?
12:10	Chouser	nope
12:10	Chouser	not even a local, if you use 'doto'
12:10	Chouser	(doto (new JavaClass) (.setFoo 5))
12:13	rhickey	Chouser, scgilardi: It would be nice if this new improved use/require thingy had a completely new name, and vastly simpler syntax and semantics than use/require currently do, i.e. if you pick a new name, even :uses, you get a clean slate for a simpler design
12:13	rhickey	I can never remember how to use use and require
12:13	Chousuke	heh.
12:19	scgilardi	I'm open to suggestions. Other than collapsing both use and require into one thing, I don't see obvious opportunities for vast simplification.
12:20	rhickey	scgilardi: doing less is an opportunity
12:20	rhickey	the use of the nested vector is tricky too
12:22	scgilardi	please explain re: doing less
12:24	rhickey	well, I haven't thought it through, but right now it is undeniably complex, so it begs the question what would be simpler? where is there redundancy? what is infrequently used?
12:25	rhickey	e.g. foo.bar.baz vs (foo.bar baz) seems like a feature but adds complexity
12:26	scgilardi	removing the opportunity to use prefix lists to extract out common prefixes would lead to simpler, but more redundant ns forms.
12:27	rhickey	scgilardi: I thought we'd go the other way
12:28	rhickey	having just :uses vs :require and :use is good in and of itself
12:28	rhickey	the nested structure is also tricky
12:29	rhickey	I can't design it right now, just encouraging a search for simplification
12:29	scgilardi	that sounds like a good direction. we could remove the vectors perhaps by recognizing symbols as distinct from keyword value pairs in the same way that clojure cond is simpler than CL cond.
12:29	scgilardi	ok, I'll give it some thought
12:30	Chouser	if we only allow (foo bar) instead of foo.bar, would it be acceptible to remove one nesting level? (:uses (foo bar :as fr baz :as fz)) ?
12:30	Chouser	eh
12:30	Chouser	nm, I don't like that
12:31	scgilardi	Along the lines of the "circular load" issue, I'm giving some thought to a design for removing the need for :reload and :reload-all by using the resource mod dates like the compiler does.
12:31	rhickey	scgilardi: sounds appealing
12:32	scgilardi	rhickey: I'll write up what I have and post it to the developer's list.
12:32	rhickey	scgilardi: thanks!
12:33	scgilardi	chouser: what if "fr baz :as fz" were on a separate line. That kind of construct is what I was talking about for removing the vectors above.
12:34	rhickey	commas are free too
12:34	rhickey	(:uses (foo bar :as fr, baz :as fz)
12:35	rhickey	ignored but useful still
12:37	rhickey	(:uses (foo bar {:as fr} baz {:as fz :refer bleh}))
12:39	rhickey	nice because adding options doesn't require restructuring
12:39	Chousuke	I don't see the point of "foo bar" instead of foo.bar
12:39	Chousuke	or is it importing two libraries? :/
12:39	rhickey	right 2
12:40	rhickey	share prefix
12:40	cemerick	where's the prefix, then?
12:40	scgilardi	For simplifying, I like them being inline better than collected in maps. Adding option wouldn't require restructuring in that case either. A keyword implies a subsequent value.
12:40	rhickey	cemerick: foo.bar and foo.baz
12:40	cemerick	ah.
12:41	rhickey	scgilardi: but a lot harder to parse, even with commas
12:41	rhickey	better with newlines
12:41	scgilardi	but compare: (:uses (foo [bar :as fr] [baz :as fz :refer bleh]))
12:42	rhickey	scgilardi: I really dislike that because the two names are at different nesting levels when no options
12:42	rhickey	(:uses (foo bar [baz :as fz :refer bleh]))
12:43	rhickey	ick^
12:43	scgilardi	ok, I understand that
12:44	rhickey	saving typing is a non-objective here, we want clarity and somewhat guessable syntax
12:45	Chousuke	I like the map approach.
12:46	rhickey	maps might be a little easier on tools, they definitely are parsing this ns stuff right now, with a lot of hair-pulling
12:48	scgilardi	I don't mind maps. There is a tension between regularity and succinctness though. I trust we don't want to see empty maps when there are no options.
12:48	scgilardi	absolutely regular: (prefix name opts name opts name opts)
12:49	Chousuke	well, '(' prefix (lib-name option-map?)+ ')' would still be very simple
12:50	scgilardi	I agree. I think we should remove the limitation that lib-name can't have any dots in it. I'd like to be able to express (:uses (clojure.contrib sql sql.test)) without requiring two :uses clauses.
12:51	scgilardi	Also, if we do end up with :uses, we could also change to :imports and break the (perhaps) unfortunate one to one mapping between ns keywords and like-named functions.
12:51	scgilardi	ns being declarative in English as well as intent would be a plus I think
12:55	Chousuke	Why aren't dots allowed in lib names currently, anyway?
12:55	cemerick	rhickey: surely I don't have to point you towards AppleScript :-P
12:55	cemerick	besides, this isn't about naming at all, is it?
12:55	Chousuke	cemerick: what applescript does is called "taking it too far"
12:55	Chousuke	cemerick: it's still important :)
12:56	rhickey	cemerick: it's both, use vs uses is naming, the structural stuff is not
13:39	krl	anyone using clojure with sesame?
13:40	jackdempsey	no, but sounds delicious
13:41	duck11231	I hadn't tried sesame, but i did some work with jena
13:41	duck11231	until I abandoned it to go a different way
13:41	krl	i need a good rdf store without coding java. :)
13:43	duck11231	I found that I liked Jena better as a RDF store when I was evaluating both
13:43	duck11231	plus, jena worked better with Topbraid Composer.
13:43	weissj	can someone tell me what's wrong with this (trying to process xml): (clojure.contrib.zip-filter.xml/xml-> myxml :entry)
13:43	weissj	1:48 jon-install=> java.lang.ClassNotFoundException: clojure.contrib.zip-filter.xml (repl-1:47)
13:44	weissj	i need slashes?
13:44	krl	duck11231: what was better with jena?
13:44	Chousuke	weissj: that looks fine
13:45	duck11231	It's been so long since I looked at the two. I think I needed inferencing that sesame wouldn't give me right
13:45	duck11231	plus Jena was easier for me to learn
13:45	weissj	Chousuke: do you know why i'm getting the ClassNotFoundException? isn't that code supposed to be in the contrib jar?
13:45	Chousuke	weissj: you probably need to require it
13:46	Chousuke	weissj: using the fully-qualified name to get to unimported stuff only works with java.
13:46	weissj	Chousuke: ah
13:48	weissj	Chousuke: (require 'clojure.contrib.zip-filter.xml) ?
13:48	Chousuke	yeah.
13:48	duck11231	Chousuke: really? I could've sworn I've done something like that and it worked. (although it may have been required in a different ns)
13:48	weissj	(xml-> myxml :entry)
13:48	weissj	1:54 jon-install=> java.lang.Exception: Unable to resolve symbol: xml-> in this context (repl-1:53)
13:48	Chousuke	weissj: require is not use.
13:48	Chousuke	weissj: after requiring, you can use the fully-qualified name :)
13:49	weissj	oh
13:49	Chousuke	alternatively, (require '[clojure.contrib... :as xml]
13:49	Chousuke	)
13:49	Chousuke	and then (xml/xml-> ...)
14:19	weissj	ok, so i see how to parse xml with zip_filter/xml, but how do i edit the structure? ie, i found the element and want to replace it with something else
14:20	Chouser	weissj: use the functions in clojure.zip
14:25	weissj	Chouser: i see there's a zip/replace... but not sure how to use that. is there an example somewhere of finding something in xml and replacing with something else
14:28	Chouser	http://paste.lisp.org/display/71471
14:29	weissj	Chouser: thanks!
14:30	Chouser	if you think you might ever need to change more than one item found by a filter (ie. changing every <b> tag or something), zip-filter is going to let you down
14:31	Chouser	in that case (and perhaps in every case) I'd recommend you look at enlive
14:42	weissj	Chouser: for my purposes right now, i'm doing one edit at a time. having trouble figuring out how to replace the value of an attribute tho
14:48	cemerick	am I right in thinking that there's no var I can bind to prevent the runaway printing of circular datastructures?
14:49	Chouser	print-level
14:49	Chouser	,(doc print-level)
14:49	clojurebot	"; print-level controls how many levels deep the printer will print nested objects. If it is bound to logical false, there is no limit. Otherwise, it must be bound to an integer indicating the maximum level to print. Each argument to print is at level 0; if an argument is a collection, its items are at level 1; and so on. If an object is a collection and is at a level greater than or equal to the value bound to *print-l
14:51	cemerick	yeah, that I know about -- I was hoping to retain unlimited print-level and print IDs or something for recursively-referenced objects
14:51	Chouser	oh, you mean for IDerefs in particular
14:51	cemerick	yeah
14:52	cemerick	though it's a general problem for anyone writing a print-method or print-dup impl for, say, a regular Java class
14:52	Chouser	or even .toString
14:52	cemerick	yeah
14:53	Chouser	then even print-level doesn't help
14:54	cemerick	I guess I'm looking for something like #1={:foo #1#}
14:54	Chouser	oh. my.
14:55	Chouser	I guess that's not unreasonable. Does pprint do something like that?
14:55	cemerick	hrm, that's an idea
14:55	Chouser	,(let [x (java.util.HashMap.) y (java.util.HashMap.)] (.put x :y y) (.put y :x x) (.toString x))
14:55	clojurebot	java.lang.StackOverflowError
14:57	cemerick	nope, pprint doesn't help -- although it looks like the beginnings of an impl of that sort of thing is in pprint/dispatch
14:59	Chouser	hm, this shouldn't be hard
14:59	cemerick	no, one just needs to track the objects that have been visited so far
15:00	Chouser	IDerefs in particular
15:00	Chouser	ids are already printed
15:01	cemerick	yeah, that'd be the first target -- general support for any circular references in java objs would be a little trickier, though a general facility that any implementor of a print-method or print-dup method would be handy
15:03	Chouser	but the latter is impossible
15:03	Chouser	isn't it? that's what the java.util.HashMap example above shows
15:04	Chouser	print-method doesn't even get touched
15:04	cemerick	hrm
15:05	cemerick	there's a print-dup impl for java.util.Map, but not for print-method
15:06	Chouser	oh, overridding .toString. hm.
15:07	cemerick	so, I don't think it's reasonable to think all java classes could be covered, but standard collections seems reasonable, and whatever mechanism is used to track visited objects for IDerefs and standard collections could be reused for any other print-method impl
15:07	cemerick	Making this work with print-dup would require reader changes, of course.
15:07	cemerick	or, no, they wouldn't, nm
15:08	lisppaste8	Chouser pasted "prevent infinite print recursion for IDeref" at http://paste.lisp.org/display/83647
15:13	cemerick	Chouser: ech, I'm still on v1.0, no future?
15:13	cemerick	That looks about right, though
15:15	Chouser	oh, just take that part out
15:16	lisppaste8	Chouser annotated #83647 "without 'future' support" at http://paste.lisp.org/display/83647#1
15:22	cemerick	it works on a trivial example, but I'm still getting spews from real data. I'm trying to isolate the issue.
15:23	Chouser	hm...
15:23	Chouser	actually, binding anew at each level isn't quite what I had in mind originally
15:26	cemerick	hrm, actually, I think that might be a bug on my part
15:26	cemerick	(unsuprisingly)
15:28	ChrisPS	...
15:28	Chouser	huh. no way to find out if a var has been bound thread-locally except to attempt a 'set!' and catch the exception if not?
15:30	cemerick	Chouser: Var.getThreadBinding, but it's package-private
15:30	Chouser	right
15:34	lisppaste8	Chouser annotated #83647 "manual binding scope, without future" at http://paste.lisp.org/display/83647#2
16:05	porpoise	I made some change to a file and did (use 'mycode.myfile) and it gave me the same error as before I fixed my file. How do I get it to reload the file with the changes?
16:05	porpoise	when I restarted clojure it worked fine
16:06	Chouser	(use :reload 'mycode.myfile)
16:06	porpoise	oh
16:06	porpoise	heh thanks
16:06	porpoise	maybe I should keep a noob journal and write a noob guide
16:06	porpoise	i'm asking enough dumb questions
16:07	Chouser	http://clojure-log.n01se.net/ is my noob guide
16:07	Chouser	a bit wordy, I suppose
16:07	porpoise	cool
16:10	technomancy	porpoise: it's easier if you have editor integration
16:10	porpoise	technomancy: I'm using slime and emacs
16:10	porpoise	is there a better integrated editor for clojure?
16:11	porpoise	I was doing C-c C-l before
16:11	technomancy	porpoise: if you've already got slime set up, just use C-c C-k
16:11	technomancy	or that
16:11	porpoise	C-c C-l didn't solve my problem but (reload ...) did
16:11	technomancy	did you do C-c C-l on the file that actually changed?
16:12	porpoise	technomancy: yes. and it prompted me whether to save and I said yes
16:12	porpoise	so I thought it was weird that it didn't actually reload
16:12	technomancy	that's really strange
16:12	porpoise	maybe my setup is screwed up
16:13	porpoise	does it work properly for you then?
16:13	technomancy	do you only have one slime instance running?
16:13	technomancy	yeah, I've never had that problem
16:13	porpoise	technomancy: I'll restart emacs to check
16:13	technomancy	if you can consistently reproduce it, please submit it as a bug to the clojure mailing list
16:13	technomancy	bonus points if you can narrow it down to a simple case
16:15	porpoise	maybe i'll try it on clojurebox on my windows machine as well
16:15	porpoise	what instructions should I use to setup slime and clojure? I used
16:15	porpoise	the Bill Clementson script
16:15	technomancy	clojurebot: slime?
16:15	clojurebot	slime is best configured using M-x clojure-install once you have clojure-mode installed. Please don't configure it manually unless you know what you're doing.
16:16	technomancy	hrm; I personally heartily recommend the instructions at http://technomancy.us/126 while fully admitting that I may be biased.
16:16	technomancy	Bill Clementson's stuff is pretty outdated.
16:17	Chouser	what's do you call the class in which a nested class is nested?
16:17	Chouser	not its parent class
16:17	Chouser	its "nestor class"
16:17	j-dot	outer class?
16:17	technomancy	container?
16:17	cemerick	outer class, usually
16:17	Chouser	ah, thanks
16:17	porpoise	the nest?
16:18	cemerick	is anyone aware of a NetBeans RCP wrapper for clojure (or the start of one)?
16:19	weissj	Chouser: any hints on how to replace an xml attribute value? (xml-> z zf/descendants :foo (attr :name))
16:19	weissj	("hi")
16:19	weissj	it just returns the value, not the whole attribute. if i try to replace it with "yo" like so:
16:20	weissj	(zip/replace rpl (parse-str "yo"))
16:20	weissj	1:40 user=> org.xml.sax.SAXParseException: Content is not allowed in prolog. (repl-1:39)
16:20	Chousuke	tried with just "yo" instead of trying to parse it?
16:20	Chouser	Yeah, the attributes aren't children in xml-zip
16:21	hiredman	lisppaste8: url?
16:21	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
16:21	Chouser	you'll probably have to replace the whole element
16:22	weissj	Chouser: how can i replace the whole element, if i only know one attribute
16:22	Chouser	you'll have to not go down that far in your filter expr
16:23	weissj	Chouser: is there a way to select the element based on its attribute?
16:23	Chouser	yes
16:24	Chouser	you know the value you want, or just the existence of the attr?
16:24	weissj	Chouser: value
16:24	weissj	(xml-> z zf/descendants :foo [(attr= :name "hi")])
16:24	Chouser	right
16:24	weissj	that seems to select a lot more than the element
16:25	lisppaste8	hiredman pasted "get non-public field" at http://paste.lisp.org/display/83651
16:26	hiredman	ugh
16:26	hiredman	missing a paren
16:26	Chousuke	I like the name :P
16:26	hiredman	:)
16:27	beutdeuce	question, how do you do if-else statements?
16:27	Chouser	weissj: it's a loc object
16:27	weissj	Chouser: oh ok.. let me see if that works
16:28	Chousuke	beutdeuce: (if condition then-expr else-expr)
16:28	Chousuke	beutdeuce: see also: cond, when, if-let, condp
16:29	beutdeuce	k
16:29	weissj	Chouser: so what do i give as the 2nd arg to zip/replace, if i'm replacing <foo name='hi'>1</foo> with <foo name='yo'>1</foo> ? i can't just use that string because that code won't know the rest of that element, ie, the "1" content.
16:29	Chouser	(def changed (let [e (xml1-> z zf/descendants :foo [(attr= :name "name1")])] (zip/replace e (assoc-in (zip/node e) [:attrs :name] "new-name"))))
16:30	Chouser	so beautiful and simple :-P
16:30	Chouser	why can't I annotate that paste? too old?
16:30	beutdeuce	why doesnt this work => http://clojure.pastebin.com/m478e6cc
16:30	weissj	Chouser: yeah i seem to be giving up a lot to get thread safety when i don't need it :)
16:31	Chouser	the APIs just need work
16:31	Chouser	I have faith
16:31	Chouser	:-)
16:32	Chousuke	beutdeuce: the then and else are not part of if syntax
16:32	beutdeuce	oh
16:32	beutdeuce	k
16:32	Chousuke	beutdeuce: also, you should not put the closing parens on their own lines
16:33	Chousuke	they'll feel lonely.
16:33	beutdeuce	now, it tells me too little arguments for if
16:33	technomancy	Chousuke: that's the best reason I've heard yet. =)
16:33	weissj	beutdeuce: you need two forms, a "then" and "else" form
16:33	weissj	if you're just doing an "if" with no "else", use when
16:34	beutdeuce	k
16:34	beutdeuce	argh, still too few arguments => http://clojure.pastebin.com/m6c8cfe87
16:35	weissj	beutdeuce: there's no "then" or "else" -
16:35	beutdeuce	yes there is
16:35	weissj	there shouldn't be
16:35	weissj	example:
16:35	beutdeuce	oh
16:35	technomancy	also the "then" and "else" clauses need to be inside the last paren of the "if" clause
16:36	weissj	(if (= (+ 1 1) 2) (print "yep") (print "nope"))
16:36	beutdeuce	yeah, k , thnx
16:36	Chouser	,(if (= (+ 1 1) 2) (print "yep") (print "nope"))
16:36	clojurebot	yep
16:37	beutdeuce	does clojure do null or nil ?
16:37	Chousuke	nil
16:37	Chousuke	which equals java's null
16:37	beutdeuce	k
16:39	Chousuke	technomancy: If you want more rational reasons, I guess it reduces visual noise because lisp code tends to nest a lot; or that generally every nesting level will only have only one expression
16:39	technomancy	Chousuke: yeah, but many people don't buy that right away
16:40	porpoise	technomancy: I'm not using the emacs starter kit because I already have an Emacs setup (based on the launchpad apt-source). It seems slime is not part of ELPA? Should I just install slime manually?
16:40	technomancy	porpoise: clojure-mode can handle that for you actually with M-x clojure-install
16:41	porpoise	oh
16:42	Chousuke	I set myself up a super-emacs (moved away from aquamacs to Cocoa emacs) using http://github.com/purcell/emacs.d/tree/master as a base :P
16:42	beutdeuce	after i get the right output, i am constantly getting a null pointer exception, why is that? => http://clojure.pastebin.com/m66074d66
16:43	Chousuke	beutdeuce: you have parens around (println "true")
16:43	Chousuke	that means you're calling the return value of (println "true")
16:43	Chousuke	which is nil
16:46	arohner_	is there a version of memoize out there that only memoizes the last N values?
16:48	Chousuke	hmm
16:48	Chousuke	Can't think of any, but it should be fairly easy to make one
16:48	arohner_	yeah, I just wanted to make sure I wasn't duplicating effort
16:48	Chousuke	fetching the memoised value would have to be O(n) though
16:49	arohner_	why?
16:50	arohner_	even a naive version would probably be acceptable. I'm memoizing a fairly expensive function, and it doesn't need to store too many values ( < 1000)
16:50	Chousuke	well, you have to remove the old values at some point I guess. how are you going to know which values are old if you have just a map?
16:50	clojurebot	map is LAZY
16:50	Chouser	you'd definitely need more bookkeeping
16:50	arohner_	yeah
16:51	arohner_	the memoized function is run as part of a webpage, and the values can change over time, so unbounded memory growth is not acceptable
16:54	Chouser	you'd probably want lru, so a lookup causes an entry to be immune from deletion for a while
16:54	Chousuke	you could always do periodic "garbage collection" on the memoised map.
16:55	Chouser	if you had a map of args -> lookup-seq-num, that could be updated in constant time for each cache hit
16:55	Chousuke	yeah. then go through it every once in a while and remove entries from the actual memorised map that are too old
16:55	Chouser	but then on insert you'd have to O(1) walk that map looking for low-numbered values
16:58	porpoise	I just started using the clojure-install setup from ELPA. What's the correct way of adding my code directory to the search path, and add my java classpaths and native libraries?
16:58	porpoise	Previously I was directly editing slime's invocation of java
16:59	Chousuke	swank-clojure-extra-jar-paths or something?
16:59	Chousuke	it's in the customize group for swank-clojure
17:01	porpoise	thanks
17:02	lisppaste8	hiredman annotated #83651 "wall-hack-method" at http://paste.lisp.org/display/83651#1
17:02	technomancy	porpoise: it's actually generally easier if you extract all your dependencies in one place rather than adding jar files to your classpath one-by-one
17:04	beutdeuce	Chousuke: if i remove parens around println "True", it says if has too many args
17:10	technomancy	beutdeuce: remove just one pair of parens
17:11	beutdeuce	technomancy: still says too many args:
17:11	beutdeuce	(defn elem
17:11	beutdeuce	[x xs]
17:11	beutdeuce	(if (= x (first xs) )
17:11	beutdeuce	print "True"
17:11	beutdeuce	(if (= (rest xs) nil) print "False" ((elem x (rest xs))))))
17:12	technomancy	beutdeuce: you removed two levels of parens around print "True"
17:13	technomancy	also you didn't put it inside the if expression like I said
17:13	beutdeuce	could u please paste the right version, i'm a bit confused right now
17:13	technomancy	sure, but I think you might want to take a step back and try reading some more existing code before you proceed.
17:15	technomancy	here's the working version: http://clojure.pastebin.com/m1cbcfc5f
17:17	beutdeuce	i appreciate your help
17:17	technomancy	np; I hope you get things figured out
17:17	beutdeuce	say, is ther infix notation on clojure, like in haskell `` ?
17:17	Chousuke	no
17:17	hiredman	ugh
17:17	beutdeuce	k
17:20	Chousuke	beutdeuce: lisp has this concept of "forms". a single form evaluates to a single value. a form is either "atomic", or a composite form. '5', '"foo"', 'bar', ':bar' etc. are atomic forms. '(print "2+2=" (+ 2 2))' (a list) '["foo" 5]' (a vector) etc. are composite forms. composite forms. list composite forms are evaluated specially in that the first item in the list composite form
17:20	Chousuke	is considered an "operator" and the rest are the arguments; so, the list form evaluates to whatever that operator called with the arguments returns.
17:20	Chousuke	beutdeuce: further, there are macros and special forms which can "bend" the rules a bit.
17:21	mariorz	what should I use to parse a huge xml file without loading the whole thing to memory?
17:22	Chouser	mariorz: you can try clojure.contrib.lazy-xml
17:22	mariorz	Chouser: cool
17:22	Chouser	but it's pretty easy to accidentally bring in the whole thing
17:23	Chouser	I'd be interested to know how it works out for you.
17:23	mariorz	why accidentally?
17:23	Chousuke	beutdeuce: if is one example of a special form; but if you look at '(if (= 2 2) "yay" (print "nay"))', it is still the if operator, called with three arguments: the condition, the form that is evaluated and returned if the condition is true, and the form that is evaluated and returned when the condition is false.
17:24	Chouser	mariorz: if you have <doc><t1>...10GB of nested data...</t1><t2>foo</t2></doc>
17:24	Chouser	mariorz: ...and you ask for doc's second child, the whole thing gets parsed
17:24	beutdeuce	Chousuke: k
17:25	mariorz	Chouser: makes sense, ill let you know how it owrks out
17:25	Chousuke	beutdeuce: in this case, the second argument gets evaluated and returned, yielding the value "yay"; if the condition were instead false, the third argument would get evaluated, having the side-effect of printing "nay", in addition to yielding the value nil
17:26	beutdeuce	ah
17:27	Chousuke	beutdeuce: as if only takes three arguments, each of the result branches can only contain one form.
17:28	beutdeuce	makes sense
17:28	Chousuke	beutdeuce: sometimes, if you need to evaluate more forms (for side-effects), you can wrap them in a do form, which evaluates all its arguments in sequence.
17:28	beutdeuce	i see, like Haskell
17:28	beutdeuce	question, if i made a .clj file with my elem function defn'ed in it, is there a clojure function that loads it or imports it?
17:29	Chousuke	so (if true (do (print "1") (print "2")) (print "not true"))
17:29	beutdeuce	yeah
17:30	Chousuke	beutdeuce: usually, you want to declare a namespace at the top of your file
17:30	Chousuke	beutdeuce: but you can also use (load "foo") (no .clj) to just "include" a file
17:31	beutdeuce	Chousuke: cool thanks. i g2g for now. Thanks for all the help. and technomancy.
17:47	hiredman	I am always surprised when I see people who are obviously unfamiliar with clojure doing performance testing
17:48	hiredman	it seems to imply performance is the first thing people look at
17:48	hiredman	which is at odds with, well, me
17:48	Chouser	heh
17:51	mariorz	Chouser: so if I use parse-trim on the file the content wont be loaded to mem until I actually call it using :content, right?
17:52	Chouser	that's the idea
17:53	mariorz	cool
17:56	mariorz	i dont think its working
17:56	mariorz	just calling trim-space on the file makes me run out of heap space
17:56	mariorz	er parse-trim
17:56	Chouser	:-(
17:57	Chouser	what are you doing with the result of parse-trim?
17:58	mariorz	assigning it to a var
17:58	Chouser	bah. that ought to be safe.
17:58	mariorz	(def foo (parse-trim "bigfile))
17:59	fsodomka	Chouser: logging at http://clojure-log.n01se.net/ doesn't work recently for me
18:00	Chouser	mariorz: try (parse-seq "bigfile" startparse-sax 1)
18:02	mariorz	Chouser: cool, i think that works
18:03	Chouser	mariorz: ok. without that it was going ahead in the background trying to parse the whole thing.
18:03	Chouser	So I essentially lied to you before. :-P sorry.
18:03	mariorz	hah np
18:04	Chouser	fsodomka: bleh. indeed. thanks.
18:05	Chouser	fsodomka: can't fix it tonight. I'll try to get to it soon.
18:05	Chouser	I've got the logs, but they're in the wrong format, so once its fixed the intervening days should show up
18:05	mariorz	Chouser: those this mean i could use parse-trim as well as long as i suply startparse-sax?
18:06	mariorz	s/those/does/
18:06	fsodomka	Chouser: cool, looking forward to it
18:06	Chouser	no, it's the 1 that matters
18:06	fsodomka	Chouser: thanks!
18:06	Chouser	that tells the parsing thread how far ahead of the consumer it's allowed to get
18:07	mariorz	Chouser: ok, startparse-sax is the default aprser anyway?
18:07	Chouser	oh, yes -- (parse-trim "bigfile" startparse-sax 1)
18:07	Chouser	yes, startparse-sax is the default
18:07	mariorz	cool, thanks for the help!
18:08	Chouser	the pull-parser is better, but requires another jar: http://www.extreme.indiana.edu/xgws/xsoap/xpp/
18:09	Chouser	huh. that's kinda weird. Looks like if you put that xpp jar in your classpath, (parse-trim "bigfile") may just do what you want
18:10	mariorz	why?
18:11	mariorz	it automatically sets a queue size?
18:12	mariorz	ah i see
18:12	mariorz	If no parser
18:12	mariorz	is specified and org.xmlpull.v1.XmlPullParser is in the classpath,
18:12	mariorz	this superior pull parser will be used."
18:15	westajay	is there a simpler api function for testing if all elements in a collection are true?
18:15	westajay	other than doing this
18:15	westajay	(every? (fn[x] x) [true true true])
18:16	Chousuke	westajay: there's the "identity" function
18:17	scgilardi	(every? true? a-collection) (if you mean literally true and not just non-nil and non-false)
18:18	westajay	scgilardi: that works
18:19	westajay	thank you sir
18:19	scgilardi	westajay: you're welcome :)
18:20	Raynes-	,(true? (true? (true? true)))
18:20	clojurebot	true
18:20	Raynes-	True!
18:21	scgilardi	Chousuke: you asked earlier about the prohibition on periods in lib names. Rich requested that around the time he integrated the use and require stuff into Clojure. As I recall, the rationale was to keep things as simple as possible.
18:22	scgilardi	[ the prohibition I'm talking about is that this is not currently accepted: (:use (clojure.contrib sql sql.test)) ] because sql.test contains a period.
18:24	scgilardi	Before it was simplified, one could use the prefix list concept nested arbitrarily deeply: (:use (clojure (contrib sql (sql test))))
18:24	hiredman	clojurebot: CA?
18:24	clojurebot	CA is Contributor Agreement: http://clojure.org/contributing
18:29	Raynes-	I wish I had a printer, so I could print that. :(
18:30	Raynes-	I'd buy one, but hiredman took all my moneys.
18:31	hiredman	all the money you where going to get paid for NPEs
18:31	scgilardi	given his recent demise, at least that's one problem you won't have any more
18:31	scgilardi	hey!
18:42	Modius	Is clojure's "doall" a function or a macro?
18:43	hiredman	,(meta #'doall)
18:43	clojurebot	{:ns #<Namespace clojure.core>, :name doall, :file "clojure/core.clj", :line 1780, :arglists ([coll] [n coll]), :doc "When lazy sequences are produced via functions that have side\n effects, any effects other than those needed to produce the first\n element in the seq do not occur until the seq is consumed. doall can\n be used to force any effects. Walks through the successive nexts of\n the seq, retains the head and retu
18:43	Modius	Does that mean it is a function?
18:43	hiredman	,(meta #'defn)
18:43	clojurebot	{:macro true, :ns #<Namespace clojure.core>, :name defn, :file "clojure/core.clj", :line 189, :doc "Same as (def name (fn [params* ] exprs)) or (def\n name (fn ([params ] exprs)+)) with any doc-string or attrs added\n to the var metadata", :arglists ([name doc-string? attr-map? [params] body] [name doc-string? attr-map? ([params*] body) + attr-map?])}
18:43	hiredman	yes
18:44	hiredman	if it is a macro there iwll be a :macro true
18:46	scgilardi	,(doc doc)
18:46	clojurebot	"([name]); Prints documentation for a var or special form given its name"
18:46	scgilardi	clojurebot has a custom doc func?
18:47	hiredman	yes
18:47	hiredman	well, custom doc macro
18:47	scgilardi	right. is it to minimize lines of output or to solve some security problem?
18:48	hiredman	well, the way doc prints out stuff is not irc friendly
18:48	hiredman	the dashes, the spaces, etc
18:49	scgilardi	makes sense. clojure.core/doc also prints out "Macro" for macros.
18:49	hiredman	oh really
18:49	hiredman	how useful
18:55	beutdeuce	if i have a fun.clj file with (ns "lib") at the top, can i use (in-ns "lib") from Repl to load it?
18:57	hiredman	no
18:57	Raynes-	You could just load the file.
18:57	hiredman	namespace names are symbols
18:57	beutdeuce	how?
18:57	hiredman	not strings
18:57	hiredman	(ns lib)
18:57	hiredman	(in-ns lib)
18:58	hiredman	and in-ns does not load anything
18:58	hiredman	it jsut switches to another namespace
18:58	beutdeuce	how would i be able to load an external clj file?
18:58	hiredman	you can just one of the load functions or require or use
18:58	Raynes	beutdeuce: (load "path")
18:58	Raynes	hiredman: I win.
18:59	beutdeuce	doesnt work
18:59	beutdeuce	tells my no source file
19:00	Raynes	beutdeuce: It has to be on your classpath, by the way.
19:00	Raynes	I think.
19:00	beutdeuce	is there any alternative way?
19:00	Raynes	Require or use, but it still has to be on the classpath.
19:01	Raynes	Once again, I think. I never have to do stuff like this. I use Slime.
19:01	beutdeuce	hmm. whats that?
19:02	beutdeuce	works with clojure?
19:03	Raynes	It's what you specify when you start up the clojure REPL. java -cp <paths that you want on the classpath separated by :'s on *nix and ;'s on windows> -jar clojure.jar
19:03	Raynes	-cp adds whatever directories you specify to the classpath.
19:03	Raynes	For example: java -cp /home/rayne/clojure:/home/rayne/clojure2 -jar clojure.jar
19:04	Raynes	Anything in Clojure and Clojure 2 will be on the classpath.
19:04	Raynes	I don't know enough about the classpath to really /explain/ it, I just know how to use it.
19:04	Raynes	If anyone else can explain it better, feel free to step in. :)
19:05	beutdeuce	thats clear enough
19:05	beutdeuce	whats slime though?
19:05	Raynes	It's an Emacs mode for Lisp.
19:05	Raynes	Most people use it and clojure-mode+clojure-swank for their clojure editing needs.
19:06	technomancy	beutdeuce: there's an explanation/tutorial at http://technomancy.us/126
19:06	Raynes	technomancy: Thank you. I was scared to death he was going to ask something more complex about Slime. :\|
19:07	beutdeuce	:P
19:09	technomancy	hehe
19:10	lisppaste8	mariorz pasted "untitled" at http://paste.lisp.org/display/83661
19:10	mariorz	Chouser: still around?
19:10	beutdeuce	i'm on a mac and i have no idea what i set my inferior-lisp-system to, i dont even know where its located
19:11	technomancy	beutdeuce: if you read the article I linked to, you shouldn't have to configure that stuff by hand
19:12	beutdeuce	works with mac?
19:23	technomancy	beutdeuce: others have reported success
19:23	technomancy	can't test myself
19:23	beutdeuce	technomancy: nothing happens when i do M-x package-list-packages
19:26	technomancy	beutdeuce: you've triggered an obscure elpa bug I've been unable to reproduce. =\
19:26	technomancy	try restarting Emacs; if that doesn't help, rm -rf the elpa directory inside your .emacs.d and try again
19:26	beutdeuce	emacs-starter-kit in currently in ~/.emacs.d/emacs-starter-kit
19:26	beutdeuce	it should work
19:27	Knekk	Sorry, I missed the top of the discussion. This is for setting Emacs for Clojure?
19:28	beutdeuce	Knekk: yeah, trying to get emacs-starter-kit to work
19:28	Knekk	beutdeuce: where can I download that?
19:28	beutdeuce	Knekk: http://technomancy.us/126
19:28	technomancy	beutdeuce: emacs-starter-kit should actually be just ~/.emacs.d rather than nested inside it
19:29	beutdeuce	oh
19:30	beutdeuce	nice, seemed to work now
19:30	beutdeuce	woa, this is amazign
19:36	technomancy	yay =)
19:45	beutdeuce	i'm getting trouble loading slime after emacs restarts
19:48	technomancy	beutdeuce: does it work after you open a .clj file?
19:48	beutdeuce	i think i know a fix, instead of adding a call to "(eval-after-load 'clojure-mode '(clojure-slime-config))" to .emacs, i load it to init.el
19:51	beutdeuce	argh, didnt work
19:51	beutdeuce	its as if it doesnt recall slime after i restart emacs
19:52	technomancy	init.el is the equivalent of .emacs
19:52	beutdeuce	i put it there, but then it gave me an error
19:53	beutdeuce	when i take that line out, it works again, just not slime
19:53	technomancy	can you paste the error?
19:54	beutdeuce	it flashes quickly then emacs loads to default gnu screen
19:55	technomancy	right; if you switch to the Messages buffer you can see the error
19:56	beutdeuce	does it matter where i put: (eval-after-load 'clojure-mode '(clojure-slime-config)) ?
19:56	technomancy	if you're using the starter kit, put it in a file in .emacs.d named after your username + .el
19:56	technomancy	that way you won't get merge conflicts if you update to a newer version of the starter kit
19:57	beutdeuce	well, no error, but M-x slime doesnt work
19:57	beutdeuce	oh eait
19:57	beutdeuce	wrong dir
19:57	beutdeuce	h/o
19:58	beutdeuce	yeah
19:58	beutdeuce	still no slime
19:58	beutdeuce	do i have to load username.el manually?
19:58	beutdeuce	its in my .emacs.d/currently
19:59	technomancy	no, that happens for you
20:00	technomancy	try M-x slime after you've opened a .clj file
20:00	beutdeuce	(eval-after-load 'clojure-mode '(clojure-slime-config)) is whats in there, should i try to run that in emacs itself?
20:00	technomancy	no, you don't need to load it manually
20:01	beutdeuce	technomancy: yeah, it only works when i load a .clj file, is there a way to get it work without loading a clj file?
20:02	technomancy	beutdeuce: try just putting in (clojure-slime-config) instead of (eval-after-load [...])
20:02	beutdeuce	makes sense, i'll try
20:02	technomancy	recent versions do this, but my packages haven't been uploaded to elpa yet. =\
20:04	beutdeuce	yep now works, thanks for all your help!
20:05	technomancy	no problem
20:12	spaceman_stu	Hi guys - I'm trying to write a build.xml file and am getting an error saying the SAXParserFactoryImpl can't be found on the line I call an xml function from contrib. I've got the contrib jar included - any tips to getting it working?
20:22	gstamp	spaceman_stu: maybe you need to include the xerces library?
20:25	spaceman_stu	gstamp: That may well be it, but I don't understand why I wouldn't have had to deal with that before - it runs fine from slime. I'm guessing somethign with the classpath isn't right
20:28	hiredman	man, almost everything is a reader macro
20:37	skalnik	Anyone know of a good resource for Ruby programmers looking to play with Clojure?
20:40	ataggart	,(if (Boolean. "false") :weird :ok)
20:40	clojurebot	:weird
20:42	Anniepoo	skalnik, I'm learning from Stuart Halloway, Programming Clojure, it's pretty good
20:42	skalnik	I'll look into it, thanks.
20:42	skalnik	Ah, pragprog. Must be good :)
20:42	Chousuke	ataggart: I think you're supposed to use Boolean/valueOf :)
20:43	ataggart	it's good, though it helps to know a bit of java
20:43	Anniepoo	it shares the usual pragmatic problem of being more boosterish than actually informative
20:43	ataggart	chousuke: I know, just testing it out as osmeone brought it up on reddit
20:43	Raynes	Anniepoo: It's pretty informative regardless.
20:43	Chousuke	Making your own Boolean instances is weird anyway :P
20:44	Anniepoo	yes, agree
20:44	Chousuke	I wonder why it's even supported
20:44	Raynes	It's more of a "pump you up and get you going tutorial!" than a endless pit of knowledge.
20:44	Raynes	But Clojure is a Lisp. There just really isn't all that much to talk about. The proof is in the kodak.
20:45	mariorz	does map make use of seperate threads?
20:46	Chousuke	no
20:46	Chousuke	there's pmap for parallel mapping.
20:46	mariorz	im having a weird error where calling map returns a transaction not in thread error
20:47	Chouser	map is lazy
20:47	mariorz	mapping a function to a persitnat list
20:47	mariorz	no, it is but im trying out with a normal list
20:47	Chouser	but what map returns is lazy regardless
20:48	Chouser	if map is called inside a dosync, but what it returns gets passed to outside the dosync, you're likely to have problems
20:49	Anniepoo	sorry Raynes, I got distracted by RL, yes, I'd agree with you.
20:49	Anniepoo	my complaint is only that at times I feel like, in common with all the PP series, it sacrifices
20:50	Anniepoo	clarity in elucidating some boring but vital part of the language for an 'ooh wow, isn't that cool' demo
20:51	Anniepoo	but that aside, it's a pretty clear intro to the language, esp. if you're not coming from another functional language
20:54	Raynes	I've never read a pragprog book.
20:54	Raynes	I generally stick to O'Riley books.
20:54	Anniepoo	I've read many, they all have this same problem.
20:55	Anniepoo	O'Riley used to be God, they seem to have let a lot of fluff in at some point
20:56	mariorz	Chouser: http://paste.lisp.org/display/83670
20:56	mariorz	thats what i mean
20:56	Raynes	Real World Haskell is a good, comprehensive book. But it's amazing the amount of stuff they managed to screw up in it.
20:56	arohner_	Raynes: what did they screw up in RWH?
20:57	arohner_	I have the book, but I"m not a haskell expert and I didn't read it carefully
20:57	Raynes	arohner_: Various stuff, they contradicted themselves in some chapters, plenty of typos, they introduce things at the wrong time, some of the examples apparently don't even work correctly, and the coding style changes depending on whoever is writing the current chapter.
20:58	Raynes	But it still manages to be a very good read.
20:58	arohner_	I got it mainly to read about what was different in haskell rather than a serious attempt to learn it
20:59	Raynes	arohner_: You could have just read it online, if that was the case.
20:59	Chouser	mariorz: yeah, try wrapping your (map ...) in a (doall ...)
21:00	mariorz	Chouser: coolness, i get it now
21:00	mariorz	i.e. what you meant with map returns lazy
21:01	Anniepoo	I've found one error in Halloway, and it's a trivial one
21:02	Anniepoo	You know, I'm also having to deal with building a big C# library today, and the difference is truly breathtaking
21:02	hiredman	Chouser: do you know of a no-op reader macro off hand?
21:03	Chouser	#_
21:03	Chouser	or what do you mean by no-op?
21:03	Chouser	mariorz: right
21:03	hiredman	Chouser: dunno
21:03	hiredman	//no op macros return the reader
21:04	Chouser	,[1 2 3 #_ 4 5 6]
21:04	clojurebot	[1 2 3 5 6]
21:04	hiredman	from LispReader
21:05	Chouser	hm -- a reader macro can use thre reader obj as a sentinel, looks like.
21:06	hiredman	hiredman.reader=> (eval (my-read))
21:06	hiredman	(+ 1 2)
21:06	hiredman	3
21:06	clojurebot	3
21:06	Chouser	ah, a comment
21:06	Chouser	; is a reader macro
21:06	hiredman	Chouser: I see
21:07	Chouser	CommentReader.invoke() walks to the end of the line, then returns the reader as a sentinel that no form has actually been produced yet
21:08	Chouser	looks like #_ may be the only other one. It reads the following form and likewise indicates nothing has been read yet
21:08	Chouser	,(read-string "; foo")
21:08	clojurebot	java.lang.RuntimeException: java.lang.Exception: EOF while reading
21:08	Chouser	,(read-string "; foo\n5")
21:08	clojurebot	5
21:09	mariorz	:(
21:09	mariorz	im still running out of heap space
21:10	Chouser	you can make your heap bigger when you launch java
21:10	mariorz	but it should not be loading the whole file to mem this way, right?
21:11	Chouser	you're walking all the way to the end of the xml file?
21:11	Chouser	or do you stop early?
21:11	mariorz	all the way
21:11	mariorz	http://paste.lisp.org/display/83670#1
21:11	Chouser	hm... that may be the problem...
21:12	mariorz	how so?
21:12	Chouser	as in, the whole file is not loaded at the beginning, but it's probably all cached
21:12	Chouser	so if you don't bail early, it may all end up in memory after all...
21:13	mariorz	what do you mean bail early?
21:13	mariorz	like jsut parse the first x elements ?
21:14	Chouser	Right. The normal clojure.xml/parse parses the whole file before it even returns.
21:15	Chouser	but lazy-xml will parse only as much as you demand -- however if you demand all of it, it may all end up in memory after all
21:15	Chouser	hang on, gotta put a kid to bed. back in a few.
21:15	mariorz	k
21:20	mariorz	shouldnt the cache have a max size so this doesnt happen though?
21:25	Raynes	How cute. Chouser has minicoders.
21:30	mariorz	memory usage for the java process never seems to go up though
21:30	mariorz	just cpu
21:30	arohner_	right, java has a limit on how much ram it will take
21:30	Chouser	mariorz: it's the regular lazy seq caching -- each cell caches it's own value, there's no global view.
21:31	mariorz	but that low?
21:31	mariorz	around 90mb
21:31	Chouser	the solution is to make sure that you release earlier head(s) of the seq(s) as you walk through.
21:32	mariorz	the seq returned by the map right?
21:32	mariorz	Chouser: how do i do that?
21:32	Chouser	but if you're walking through (:content node), the node map is hanging onto the head so it must all end up in memory
21:32	Raynes	Chouser: How many minicoders do you have?
21:32	Chouser	none coding yet. :-)
21:33	Raynes	:)
21:34	mariorz	so the seq to which i apply the doall is lazy, but as the doall evaluates each cell in the seq its value gets cached which is what eats up the heap, is that whats happening?
21:34	Chouser	yes
21:35	Chouser	and if it's not allowed to do any processing after you leave the with-tx block, then you have a bit of a problem.
21:35	Chouser	oh!
21:35	Chouser	are you throwing away the return value of the map?
21:35	mariorz	so what would be a way around that? :)
21:35	Chouser	save_node is about side-effects?
21:36	mariorz	well it stores the node value in a db
21:36	Chouser	right -- you don't care about the return value of save_node, right?
21:36	mariorz	nope
21:37	Chouser	ok, then you should use (dorun (map ...)) or better yet (doseq ...) inside your with-tx
21:37	Chouser	well, I should warn you that I'm not sure it's possible to get what you want without restructuring lazy-xml itself
21:38	Chouser	but it might be. And even if lazy-xml is doing the right thing, using (doall (map ...)) would thwart it.
21:39	mariorz	from the api docs it would seem doseq is what i want no?
21:39	Chouser	yes
21:41	mariorz	same error
21:41	Chouser	yes.
21:42	mariorz	but why?
21:43	Chouser	now, the next thing is that bigfile is a map which contains (nested in a ways) the head of the seq you're walking through
21:44	Chouser	after your doseq is done (if it didn't run out of heap), you can still go get the first item in seq. The fact that you can means it's been stored in exactly the way that you can't allow
21:46	mariorz	didnt really understand that
21:47	Chouser	ok, let's look at a simpler example
21:47	Chouser	(let [x (map #(str "A number: " %) (range 1e7))] (last x))
21:47	Chouser	x is a very long lazy seq of strings.
21:47	Chouser	I say "is" but more accurate would of course be to say "promises to be"
21:48	mariorz	right
21:48	mariorz	becuae its lazy
21:48	Chouser	Right. Now, (last x) has to walk to the end of the seq and return the final item.
21:48	Chouser	as shown above, this will happen fairly quickly and return the result.
21:48	Chouser	,(let [x (map #(str "A number: " %) (range 1e7))] (last x))
21:48	clojurebot	Execution Timed Out
21:48	Chouser	hm, not so quickly.
21:51	Chouser	well, anyway, it should work in your repl, returning a string after a few seconds
21:51	mariorz	right
21:51	Chouser	it doesn't consume memory because nothing is able to get to the first element of x, so the JVM reclaims the memory used to cache those values
21:51	gko	Hello... How to check if an element is in a list?
21:52	Chouser	gko: perhaps a set would work better?
21:52	Chouser	mariorz: but one small change breaks it:
21:53	gko	Oh: ((set my-list) 1)
21:53	hiredman	grrr
21:53	Chouser	gko: sure, but that walks through the whole list to build that set before looking it up. Can you not use a set through your code instead of that list?
21:54	Chouser	(let [x (map #(str "A number: " %) (range 1e7))] [(first x) (last x)])
21:55	gko	Chouser: it was just a general question... I have already been using sets because of this...
21:55	Chouser	mariorz: in this case, the head of the seq is retained (so that the literal [] vector can do what it needs to), so the JVM does not release memory, and it tries to hold the entire seq in memory
21:56	Chouser	gko: ah.
21:56	Chouser	,(.contains '(a b c) 'b)
21:56	clojurebot	true
21:57	gko	(set 1 2 3)
21:57	mariorz	Chouser: ok, and this happens within lazy-xml becuase it maintains a pointer to the head of the document?
21:57	Chouser	mariorz: right. bigfile points to the whole document
21:58	ataggart	~some
21:58	clojurebot	Hello, gnuvince
21:58	ataggart	(doc some)
21:58	clojurebot	"([pred coll]); Returns the first logical true value of (pred x) for any x in coll, else nil. One common idiom is to use a set as pred, for example this will return true if :fred is in the sequence, otherwise nil: (some #{:fred} coll)"
21:58	Chouser	mariorz: I'm looking at lazy-xml's code to see if i can spot any head-retaining there, but I'm not sure...
21:58	Chouser	mariorz: so anyway, the next thing that is necessary (but perhaps not yet sufficient) is to not store bigfile globally.
21:59	ataggart	gko: use some
21:59	gko	ataggart: ?
21:59	ataggart	(doc some)
21:59	clojurebot	"([pred coll]); Returns the first logical true value of (pred x) for any x in coll, else nil. One common idiom is to use a set as pred, for example this will return true if :fred is in the sequence, otherwise nil: (some #{:fred} coll)"
21:59	mariorz	Chouser: just something like (with-tx (doall (map save_node (:content (parse-trim "file.xml" startparse-sax 1)))))
22:00	mariorz	?
22:00	mariorz	Chouser: using xpp would not help with this right?
22:01	Chouser	mariorz: try (with-tx (let [bigfile ...] (doseq [node (:content bigfile)] (save_node node)) ...
22:01	Chouser	mariorz: or what you had (but with dorun instead of doall)
22:02	Chouser	mariorz: this step is necessary anyway. it's possible yet that lazy-xml itself is hanging onto something, in which case the xpp code path may be better (or worse) ... not sure yet.
22:02	mariorz	doseq or dorun?
22:02	Chouser	I prefer doseq. It's your choice.
22:02	Chouser	both return nil which is the critical thing
22:02	mariorz	k
22:03	mariorz	thx again for the help, going for a bite and will mess aorund some more later
22:03	gko	ataggart: Oh OK... any reason why lists are not functions like maps or sets?
22:04	ataggart	in what sense?
22:04	Chouser	mariorz: ok
22:04	gko	(my-map key) => value
22:04	ataggart	gko: ah because sets and maps have O(1) access on their keys
22:04	ataggart	so they can act as functions
22:05	ataggart	contains? only works on keys, which lists dont have
22:05	gko	ataggart: right...
22:05	ataggart	(contains? [:a :b :c] 2)
22:05	ataggart	,(contains? [:a :b :c] 2)
22:05	clojurebot	true
22:06	ataggart	if you want to spin through a list, you can do it with some
22:06	Chouser	,(some #{'c} '(a b c))
22:06	clojurebot	c
22:07	gko	why , in front of your samples?
22:07	ataggart	it tells clojurebot to execute it
22:07	ataggart	though it sometimes excutes code anyway
22:08	ataggart	it's feisty
22:08	gko	,1
22:08	clojurebot	1
22:08	gko	:)
22:08	gko	couldn't clojurebot puts the evaluated expression?
22:09	gko	that's nice
22:11	ataggart	~botsnack
22:11	clojurebot	thanks; that was delicious. (nom nom nom)
22:25	hiredman	do clojure's tests include reader tests?
22:30	arohner_	hiredman: some
22:30	arohner_	there's a clojure.test-clojure.reader ns
22:31	arohner_	it's hardly comprehensive
22:31	hiredman	well
22:32	hiredman	my wrapper around LispReader passes that, so it's time to start replacing bits and pieces
22:32	arohner_	what are you working on?
22:33	hiredman	replacing Lispreader.java with clojure code
22:34	arohner_	cool
22:34	hiredman	http://github.com/hiredman/reader/blob/afb9e6266358fc965c9572a1cafc57dc15908e42/hiredman/reader.clj
22:50	arohner_	sigh. Why does java provide SimpleDateFormat, and then not provide constants for really common date formats, like RFC 822 and ISO8601?
23:23	durka421	why doesn't clojure support java variadic methods (like PrintWriter/printf) without to-array?
23:35	arohner_	durka42: java variadic methods are sugar for "normal" functions that take arrays
23:35	durka42	i suppose there's no way for clojure to detect them without reflection
23:35	durka42	or maybe even with the use of reflection
23:36	durka42	i know they take arrays, hence my (slight) annoyance at having to play with to-array
23:45	durka42	i had caps lock and couldn't figure out what the _hell_ vim was doing
23:45	slaney	heh
23:45	slaney	I have done that
23:46	slaney	more than once
23:46	slaney	adl
23:46	slaney	sadly