#clojure – 2011-01-01

2011-01-01

00:00	Crowbar7	Happy New Year!
00:00	qbg	Still an hour to go here
00:00	Raynes	Happy new year for those in the eastern time zone.
00:00	Raynes	qbg: Likewise.
00:01	programble	stupid non-easterners
00:10	auser	okay... so um... I have a LazySeq... can I transform it into a non lazy sequence?
00:11	qbg	,(doc doall)
00:11	clojurebot	"([coll] [n coll]); When lazy sequences are produced via functions that have side effects, any effects other than those needed to produce the first element in the seq do not occur until the seq is consumed. doall can be used to force any effects. Walks through the successive nexts of the seq, retains the head and returns it, thus causing the entire seq to reside in memory at one time."
00:11	qbg	^ Likely what you want
00:12	auser	I see... can you do a filter inside of a doall?
00:12	qbg	,(doall (filter odd? (range 10)))
00:12	clojurebot	(1 3 5 7 9)
00:13	qbg	doall works on any seq
00:14	Raynes	&(apply str (reverse (map #(.toUpperCase (str %)) (interleave [\r \e \space \e \space \p \a] [\a \y \w \n \y \p \h]))))
00:14	sexpbot	⟹ "HAPPY NEW YEAR"
00:15	auser	nm, it worked
00:15	auser	thanks
00:17	qbg	Tasty new year goodness: https://github.com/qbg/syntax-rules/wiki/defn-implementation
00:18	cemerick	qbg: looks like you've got something serious cooking over there :-)
00:19	qbg	git log --oneline \| wc -l reports 42 commits so far...
00:20	qbg	Templates are terrible; I need to create more powerful ones sometime later
00:21	qbg	I also need to get it supporting lexical scope in +code templates
00:21	qbg	And fix the progress implementation
00:21	qbg	etc. sigh
00:24	qbg	The pattern matcher could be cleaned up too; its currently 471 lines in a single file
00:25	qbg	Should do an alpha release either tomorrow or the day after
00:28	cemerick	qbg: the defn walkthrough helps me see things dimly :-)
00:29	cemerick	Some side-by-side syntax-quote vs. syntax-rules macros would likely be a good addition.
00:29	qbg	Yeah, it needs to be improved before I make a release
00:30	qbg	syntax-quote annoys me so much right now; I'm basically reimplementing it in the templates
00:30	qbg	I want to snarf parts of it, but its implemented in the reader...
00:32	qbg	cemerick: I've reimplemented a few macros from core in src/qbg/syntax-rules/examples.clj
00:32	qbg	https://github.com/qbg/syntax-rules/blob/master/src/qbg/syntax_rules/examples.clj
00:39	qbg	I also need to change the name; its actually syntax-rules + syntax-case, with many of the advanced patterns from syntax-parse also being supported
00:41	cemerick	I guess I'll finally have to buckle down and learn them finally :-)
00:44	qbg	syntax-rules and syntax-case are easy enough
00:45	qbg	syntax-parse is quite new (it has been in Racket for about a year)
00:46	qbg	It adds more powerful patterns and a focus on good error messages
00:46	qbg	Who can resist good error messages for free after all?
00:58	qbg	Happy New Years from CST
01:02	Raynes	qbg: Happy New Years! :>
01:02	qbg	:D
01:03	qbg	I wonder what will happen in the next year of Clojure
01:03	qbg	About this time last year 1.1 was released; so much has happened since then
01:03	Raynes	qbg: At least two books will come out sometime in the early months of 2011. Another Conj conference in October. Rich Hickey's hair will become more curly. All sorts of awesome stuff.
01:04	qbg	(read: Clojure development has _NOT_ stalled)
01:11	ivey	Raynes: happy new year
01:11	ivey	'bama time
02:05	Gigaroby	happy new year everyone
06:44	ejackson	Happy 2011 #Clojure.
06:44	kumarshantanu	ejackson: +1
06:46	xenyl	1 year to go for 2012, cool :)
06:50	ejackson	although today is 1/1/11 which is worth celebrating, if only for the fact that the US and rest of the world can agree on how to write it. :)
06:52	kumarshantanu	ejackson: more debatable date of th year -- 11/11/11
06:55	ejackson	that's more fun
06:55	kumarshantanu	Japan probably writes yyyy-mm-dd, so I guess 11/11/11 will get them too ;-)
06:56	Adamant	kumarshantanu: I don't think anyone does that unless they do ISO dates
06:56	Adamant	that's kinda why they chose it
06:56	Adamant	less to bitch about while being unambiguous
06:57	ejackson	love the Japanese
06:58	kumarshantanu	Adamant: ISO dates are such a spoilsport grin
06:59	Adamant	:P
06:59	Adamant	trolling, trolling, to keep those lines scrolling
06:59	Adamant	I almost lost control and, replied!
07:02	fliebel	good morning, and happy new year!
07:07	kumarshantanu	fliebel: happy new year (oh.. what's the IRC mechanism of RT?)
07:07	fliebel	$sed -kumarshantanu s///
07:07	sexpbot	fliebel: Format is sed [-<user name>] s/<regexp>/<replacement>/ Try <prefix>help sed
07:07	kumarshantanu	RT as in Re-Tweet
07:08	fliebel	I was trying to trick sexpbot into repeating your message :
07:08	fliebel	:)
07:10	kumarshantanu	$sed -fliebel s/x/x/
07:12	kumarshantanu	can anybody talk about how are dynamic vars distinguished from static ones in Clojure 1.3 ?
07:13	kumarshantanu	what is the syntax?
07:13	kumarshantanu	do I still get to earmuff them etc?
07:17	fliebel	kumarshantanu: I don't know much about them, but it seems rather quiet in here, so I'll just try my best.
07:17	kumarshantanu	fliebel: sure, please go ahead
07:18	fliebel	From what I understand, vars are static by default in 1.3, so you can't change them at all.
07:18	fliebel	An optimization of some sort.
07:18	fliebel	Then you can add ^:dynamic metadata to them, and they work like vars work currently.
07:19	fliebel	earmuffs are still a good convention for marking dynamic vars, but it just that, a convention.
07:20	kumarshantanu	fliebel: is it like (def ^{:dynamic true} dyn "ha ha, dynamic") ?
07:21	fliebel	kumarshantanu: I never use metadata much, but if that is the syntax, yes.
07:22	kumarshantanu	fliebel: Okay...in fact I am writing some code using 1.2 that I might adjust to support 1.3
07:23	kumarshantanu	fliebel: thanks!
07:23	fliebel	kumarshantanu: I'm sure though there was a shorthand for the dynamic.
07:26	fliebel	kumarshantanu: You might want to try this: (def ^:dynamic test "hoi")
07:27	kumarshantanu	okay..need to setup 1.3 JARs lazy :)
07:28	ejackson	my first 2011 New Years resolution is to step up to 1.3
07:31	fliebel	What is the latest 1.3 alpha?
07:33	fliebel	(and is Cake already working with that?)
07:40	kumarshantanu	alpha4 I guess, not sure about Cake
08:07	kumarshantanu	fliebel: I tested with alpha-4 -- that works, and so does ^{:dynamic true :doc "Some documentation abt the var"}
08:08	fliebel	kumarshantanu: Good.
08:10	fliebel	Does anyone in here understand Gloss? Because I don't… I'm trying to read some weird binary format.
09:35	fliebel	How can I possibly figure out Gloss? Unless I figure out the whole thing at once, I can't even toy with it: java.lang.Exception: Bytes left over after decoding frame.
09:40	mids	what are you trying to do? pastebin?
09:40	fliebel	mids: Pastebin a binary file? Strange sense of humor ;)
09:41	fliebel	I'm doing http://www.minecraft.net/docs/NBT.txt with https://github.com/ztellman/gloss/wiki/Introduction and I got this: (defcodec nbt (ordered-map :type (enum :byte :end :byte :short :int :long :float :double :bytes :string :list :compound) :name (finite-frame :byte (string :utf-8))))
09:43	mids	getting 404s on their test .nbt files
09:44	fliebel	Me to… Try this: http://dl.dropbox.com/u/10094764/World2.zip
09:44	fliebel	Is there an easy way to look at binary files to study the actual data?
09:45	mids	on unix; hexdump
09:46	kumarshantanu	fliebel: maybe you should develop functions to output/parse binary files vs "od -x filename.bin" first for pastebin ;-)
09:48	fliebel	kumarshantanu: I don't think I get you…
09:48	mids	fliebel: are you gunzipping the data before decoding?
09:48	kumarshantanu	pastebin won't take binary files, so why not paste the output of this -- $ od -x filename.bin
09:49	fliebel	mids: No, I'm putting them through GZIPInputStream ;)
09:51	fliebel	http://pastebin.com/0CW1KRDK
09:51	fliebel	What are all the null bytes?
09:53	fliebel	What is supposed to be there I think is 0a 0a and then 10 bytes of text.
09:54	kumarshantanu	generally ZIP uses symbols to pack data...null bytes may be the filler for every block
09:54	fliebel	kumarshantanu: But this is not zipped data anymore, right?
09:55	kumarshantanu	fliebel: oh, didn't notice that..okay
09:58	fliebel	So, the strange thing is that there are more bytes then I expected reading the spec.
11:05	ruhe	Hi folks. I'm trying to pass sequence to function which accepts an "&" argument. But without any success yet. Is this possible? Example: < (struct mystruct (map fn collection)) >
11:05	fliebel	ruhe: apply?
11:06	ruhe	fliebel: could you please provide an example?
11:06	raek	&(max 1 2 3)
11:06	sexpbot	⟹ 3
11:07	raek	&(apply max [1 2 3])
11:07	sexpbot	⟹ 3
11:07	ruhe	ok, got it
11:07	ruhe	thanks guys
11:07	raek	also (apply f a b c [d e f]) is the same as (apply f [a b c d e f])
11:08	raek	so you can add some arguments in front of the ones from the collection
11:18	BobFunk	anyone here using got the clojure bundle for TextMate to work with rvm?
11:37	currentB	`(reduce #(into [] %) [1 2 3 4 5])
11:38	currentB	&(reduce #(into [] %) [1 2 3 4 5])
11:38	sexpbot	java.lang.IllegalArgumentException: Wrong number of args (2) passed to: sandbox6382$eval8585$fn
11:39	raek	&(reduce conj [] [1 2 3 4 5])
11:39	sexpbot	⟹ [1 2 3 4 5]
11:39	currentB	thanks :)
11:39	raek	into is defined using reduce and conj
11:40	raek	&(into [] [1 2 3 4 5])
11:40	sexpbot	⟹ [1 2 3 4 5]
13:55	fliebel	Can anyone help me with reading some binary data with Gloss? Gloss: https://github.com/ztellman/gloss/wiki/Introduction Data: https://github.com/preble/InsideJob/raw/master/test.nbt Spec: http://www.minecraft.net/docs/NBT.txt Code: http://pastebin.com/M4KA6am1
14:22	Null-A	My job uses clojure, starting in a few days :)
14:22	Null-A	need to learn it
14:23	Null-A	I really liked "How to write a scheme interpreter in haskell" is there anything similar for clojure?
14:28	qbg	People have done exercises from SICP in Clojure
14:36	Null-A	qbg: interesting, hadn't heard of SICP
14:36	qbg	It is a classic book
14:36	qbg	Uses Scheme, but is more about programming than Scheme
14:36	Null-A	have you read joy of clojure?
14:37	qbg	I've looked through it
14:37	qbg	Programming Clojure is another good book
14:37	Null-A	what do you think is the best starting point between the two?
14:37	Null-A	or the three
14:37	Null-A	I know some haskell, and lots of C++
14:37	Raynes	Programming Clojure is fairly outdated, and will be even more outdated when 1.3 comes out.
14:38	Raynes	Practical Clojure is probably the next logical step after Programming Clojure.
14:38	Raynes	The Joy of Clojure is a fantastic book.
14:38	Null-A	nods
14:38	Null-A	maybe start there..
14:39	qbg	It's hard for me to evaluate The Joy of Clojure because I already knew a lot of Clojure by the time I read it
14:39	qbg	Seems like it should be a good book
14:43	Null-A	scip first chapter is already pretty enlightening
14:43	Null-A	sicp*
14:44	qbg	The video lectures that follow the first edition are also amazing
14:44	Raynes	Remember that Scheme and Clojure are two very different languages, albeit Lisp languages.
14:45	Null-A	Raynes: I'm reading sicpinclojure.com that should help
14:46	Raynes	:)
14:48	MayDaniel	Null-A: sicpinclojure.com is (I think) just SICP at the moment, with no Clojure.
14:48	Null-A	oh ok
14:48	Raynes	MayDaniel: It is? Darn, I presumed that at least /some/ progress had been made.
14:49	Raynes	s/presumed/assumed/
14:49	sexpbot	<Raynes> MayDaniel: It is? Darn, I assumed that at least /some/ progress had been made.
14:49	MayDaniel	I thought they'd adapted a little to Clojure, but checking the "Current Status" page, apparently not.
14:50	Null-A	Raynes: heh, that's a subtle distinction between the two terms
14:51	Raynes	$seen cemerick
14:51	sexpbot	cemerick was last seen quitting 3 hours and 5 minutes ago.
14:51	LauJensen	I saw a website with quite a few SICP lessions translated to Clojure a year or so ago
15:23	qbg	Now better explained: https://github.com/qbg/syntax-rules/wiki/defn-implementation
15:59	serp__	I have something bound to the variable x. how do I check if it's a sequence?
16:00	fliebel	serp__: ##(seq? (list 1 2 3))
16:00	sexpbot	⟹ true
16:00	Raynes	&(seq? '(1 2 3))
16:00	sexpbot	⟹ true
16:00	Raynes	&(seq? [1 2 3])
16:00	sexpbot	⟹ false
16:00	serp__	oh..
16:00	fliebel	&(coll? [1 2 3])
16:00	sexpbot	⟹ true
16:00	opqdonut_	&(not (nil? (seq [1 2 3])))
16:00	sexpbot	⟹ true
16:00	opqdonut_	that's what I use...
16:01	Raynes	opqdonut_: A vector isn't a sequence, so your example is actually incorrect.
16:01	Raynes	It is, however, sequential: ##(sequential? [1 2 3])
16:01	sexpbot	⟹ true
16:02	opqdonut_	(.class '(1 2 3))
16:02	opqdonut_	gah
16:02	opqdonut_	&(.class '(1 2 3))
16:02	sexpbot	java.lang.IllegalArgumentException: No matching field found: class for class clojure.lang.PersistentList
16:02	qbg	,(class '(1 2 3))
16:02	clojurebot	clojure.lang.PersistentList
16:02	opqdonut_	there
16:02	qbg	,(class (seq [1 2 3]))
16:02	clojurebot	clojure.lang.PersistentVector$ChunkedSeq
16:02	Raynes	PersistentList implements the seq API directly, so it is an actual seq.
16:03	opqdonut_	anyway, I find it kinda weird that a list is a sequence according to... oh
16:03	opqdonut_	okay
16:03	qbg	Don't use list? to check for seqs
16:03	fliebel	serp__: As you see, it completely depends on what you want to know and consider a sequence.
16:04	opqdonut_	indeed
16:04	Raynes	&(parents clojure.lang.PersistentList)
16:04	sexpbot	⟹ #{clojure.lang.ASeq java.util.List clojure.lang.IReduce clojure.lang.IPersistentList clojure.lang.Counted}
16:06	fliebel	&(ancestors clojure.lang.PersistentList)
16:06	sexpbot	⟹ #{clojure.lang.IPersistentStack clojure.lang.Sequential clojure.lang.IPersistentCollection clojure.lang.ASeq java.lang.Object java.io.Serializable clojure.lang.IObj java.util.List clojure.lang.IMeta java.lang.Iterable clojure.lang.IReduce java.util.Collection clojure... http://gist.github.com/762007
16:20	dsop	hmm is there a way to define a private method in a deftype?
16:21	qbg	dsop: Why would you want such a thing?
16:21	dsop	qbg: to encapsulate helper methods
16:22	qbg	Any reason why your helper methods can't be regular functions?
16:22	dsop	no, they can, just asking myself if there is a way
16:22	qbg	protocols = interfaces
16:23	qbg	So no
16:35	fliebel	dsop: Put only in the interface what belongs to the api, helper functions are an implementation details, so don't put them in a protocol.
17:15	BobFunk	trying to get https://github.com/gcv/appengine-magic to work - but can't start the app from the repl
17:16	BobFunk	works fine when running appengine-prepare and then dev_appserver.sh
17:16	BobFunk	but when trying (ae/start my-app) - I just get: java.lang.Exception: No such var: ae/start (NO_SOURCE_FILE:3)
17:31	BobFunk	hmm, why would I get "java.lang.Exception: Unable to resolve symbol: compile in this context" from the lein repl ?
17:34	tonyl	is ae imported/required/used before being used?
17:34	tonyl	I don't know about appendine-magic, but that might be a problem
17:37	leafw	hi all. 'd apreciate help on figuring out why a loop gets number boxing warnings, when it shouldn't: http://clojure.pastebin.com/9uLZqGhy
17:37	BobFunk	managed to advance a bit by including swank in the dev dependencies
17:38	leafw	the loop is defined as (loop [l (int left) r (int right)], and then only dec and inc are used on such numbers.
17:41	BobFunk	now I'm just getting a java.lang.NullPointerException when trying to start the app
17:44	BobFunk	any hints on how to get some more info on the error from the repl?
17:46	qbg	(.printStackTrace *e)
17:46	BobFunk	thanks
17:54	raek	hrm, did 'num' have something to do with this?
18:32	rak85	hi
18:34	auser	hola
18:34	auser	op later
19:51	auser	is there a way to pause a thread?
20:01	auser	or wait()
20:02	pdk	(Thread/sleep) ?
20:03	auser	no... that just sleeps
20:03	auser	basically I have a reference that holds a boolean. I want to be able to pause/resume the thread based on the value of the (ref)
20:05	auser	doesn't seem like it should be difficul
20:05	auser	t
20:06	auser	right?
20:12	pdk	hmm
20:12	pdk	this'll probably sound dumb but have you read up on the promises/futures features in clojure
20:19	auser	yeah, guess so
20:48	bendlas	(contains? (transient {:x 1}) :x)
20:48	bendlas	,(contains? (transient {:x 1}) :x)
20:48	clojurebot	false
20:48	bendlas	,(clojure-version)
20:48	clojurebot	"1.2.0"
20:48	bendlas	&(clojure-version)
20:48	sexpbot	⟹ "1.2.0"