#clojure – 2008-09-05

2008-09-05

09:02	parth_m	Hello, I want to convert (interpose \, [1 2 3 "hello"]) into a string "1,2,3,hello". Whats the best way to do this. I tried str but that gives me something "clojure.lang.LazyCons@20885a6e". I am not sure how to force it.
09:02	rhickey	parth_m: (apply str ...)
09:02	parth_m	Ah. Works perfectly. Thanks :)
11:21	wwmorgan	what's the idiomatic way to produce an IPersistentMap from a java.util.Map?
11:22	Chouser	the other direction has come up a couple times, with no clear right answer.
11:22	rhickey	wwmorgan: are you sure you need one? you can do a lot with Maps directly
11:23	wwmorgan	yeah I can work with a Map if there's no easy way to get a clojure map from it
11:24	rhickey	wwmorgan: there is: (into {} amap)
11:26	wwmorgan	that looks like it's exactly what I need thanks
11:27	Chouser	for the other direction, since PersistentMap doesn't implement java.util.Map, would it make sense to provide some kind of simple proxy wrapper?
11:28	rhickey	Chouser: I thought someone was doing that - (jmap m)
11:28	Chouser	yeah, I hadn't heard your opinion on it.
11:28	rhickey	there was much discussion here a while back
11:28	Chouser	oh, ok. nm, then.
11:30	rhickey	Chouser: no search on clojure-log
11:30	Chouser	nope, I rely on google for that, which unfortately lags by a week or two.
11:31	rhickey	Chouser: of course - http://clojure-log.n01se.net/date/2008-07-18.html
11:33	rhickey	JavaMapOnPersistentMap class, implements Map and IPersistentMap
11:34	Chouser	oh dear -- pastebin pastes expire.
11:34	DrewR	lisppaste8: url
11:34	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
11:34	DrewR	:-)
11:35	Chouser	DrewR: do you know how long those stick around?
11:35	DrewR	I don't think they have any expiry.
11:35	Chouser	ok, great.
11:36	rhickey	iirc meredydd's version wasn't quite it
11:36	DrewR	Regarding the conversion from Clojure's data structures to Java's collections, in my case it seemed too problem-dependent to do generically.
11:36	DrewR	I would love to see a generic solution though.
11:37	rhickey	DrewR: other than maps, Clojure's collections implement the corresponding Java interfaces and need no conversion
11:38	Chouser	DrewR: this was your solution, I believe: http://paste.lisp.org/display/65710
11:39	lisppaste8	drewr pasted "clojure-java data conversion" at http://paste.lisp.org/display/66351
11:39	Chouser	someone else I think wrote a proxy that kinda worked, but I'm not finding it now.
11:39	rhickey	implementing Map is a bit of a pain, but the idea would be the wrapper wouldn't involve any copying
11:39	Chouser	right
11:40	rhickey	also not in the implementations of entrySet/keySet/values
11:40	rhickey	which means it is best written in Java using the Abstractxxx helper classes
11:40	Chouser	the proxy code I'm thinking of proxied entries and such as well, I think.
11:41	rhickey	Chouser: I don't recall seeing that - I thought it copied
11:42	rhickey	anyone have a problem with the rational? predicate including BigDecimals?
11:45	Chouser	I've never done much with either, so no objection here. :-)
11:48	Chouser	This may be what I'm thinking of: https://gist.github.com/4212/268fbf9bb07cbd458f880fa6c1ca414c5ccc7ca8
11:49	rhickey	Chouser: lots of copying there
11:50	Chouser	oh. indeed.
11:50	Chouser	(set ...)
11:54	rhickey	I've added a bunch of predicates to boot.clj
12:01	Chouser	nice
12:02	Chouser	It'd be nice if the inheritence chart showed those predicates at appropriate nodes.
13:16	abrooks	Ah, hurrah! (even? ) and (odd? )! I can now remove those from my laundry-list-of-things-to-ask-rich-about-later library.
13:16	abrooks	rhickey: Thanks for the the predicates! ;-D
13:20	abrooks	rhickey: I defined even? and odd? differently so they can handle floats:
13:20	abrooks	(defn even? [n] (= 0 (rem n 2)))
13:20	abrooks	(defn odd? [n] (= 1 (rem n 2)))
13:20	abrooks	bit-and doesn't like floats.
13:21	DrewR	Are floats commonly queried for odd or evenness?
13:21	DrewR	I'm not sure I've ever needed to do that.
13:21	rhickey	abrooks: you're welcome, although if people start saying (not (empty? x)) I'm taking it out :)
13:21	abrooks	DrewR: I don't know. I didn't want to stop other people from doing that. :)
13:22	abrooks	Heh.
13:22	rhickey	Chouser: ouch
13:22	Chouser	I'm lying. I'm happy to use (when (seq x)) like a good boy.
13:24	abrooks	DrewR: You're probably right. One should int/bigint before using odd?/even?
13:24	DrewR	Chouser: Have you played with JAXP at all?
13:25	Chouser	DrewR: nope.
13:27	rhickey	Anyone looked at GXP yet? http://code.google.com/p/gxp/
13:27	rhickey	It looks like it could be a useful part of a Clojure web pipeline
13:27	Chouser	rhickey: still have the browser tab open from last time you asked.
13:28	rhickey	heh
13:28	Chouser	but no.
13:28	rhickey	I've looked at it a bit more - seems to be a well designed _functional_ template engine, delivered a la carte so no ties to a bigger framework
13:30	rhickey	get for free: structural validation, escaping, whitespace removal, internationalization
13:31	rhickey	easy to use resulting objects in a Clojure servlet
13:31	rhickey	could gen gxp from Clojure
13:31	Chouser	so you don't have to write in xml
13:31	DrewR	Hm, I seem to remember looking at this.
13:32	rhickey	right, but makes the job of the Clojure 'template' engine much simpler. It's unlikely a homemade engine will do all of those things anytime soon
13:33	rhickey	Plus it does the right thing by not supporting arbitrary code in pages, IMO
13:34	rhickey	each page is a function, they understand Iterable, we could pass Clojure data structures and have gxp loop tags destructure them
13:35	rhickey	Used by Google Adwords/AdSense/Checkoput/Blogger/Analytics/Reader etc
13:36	abrooks	rhickey: How do you feel about "_" as numeric "comma" allowing thousands, or bytes/words/longwords (hex/octal) to be visually clear?
13:36	abrooks	I've been meaning to ask this in the group but I'm to lazy^H^H^H^Hbusy these days.
13:36	rhickey	abrooks: dunno, aren't there international standards for this stuff too?
13:37	abrooks	It's part of C99.
13:37	abrooks	Other languages (Ruby, IIRC) support this too
13:37	abrooks	I don't recall that Java does.
13:38	Chouser	ooh, we could use unicode mini spaces.
13:38	rhickey	1 000 000 000
13:39	rhickey	ha
13:39	abrooks	ohhereitis
13:39	abrooks	A mini-spacebar is notably different than a space mini-bar which they might enjoy on the ISS.
13:48	Chouser	1 000 000
13:48	tomhickey	1 000 000 000
13:48	Chouser	jinx?
13:48	tomhickey	Chouser: lol, good timing
13:49	Chouser	but I can't tell with this client what you actually used.
13:49	Chouser	I used 0x2009 "thin space"
13:49	tomhickey	hair space U+200A
13:50	tomhickey	http://en.wikipedia.org/wiki/Space_character#Table_of_spaces
13:51	Chouser	maybe a no-break space would be more appropriate, like U+202F
13:51	rhickey	you guys are crazy
13:51	rhickey	:)
13:51	tomhickey	:)
13:51	Chouser	:(
13:54	rhickey	the only reason Mathematica can get away with it is that when you copy 1 000 000 000 it pastes elsewhere as 1000000000
13:54	Chouser	Breaking up a numeric literal would be optional. If you have an out-of-date keyboard with no U+200A, you can just skip it.
13:55	rhickey	the copy paste issue is the biggie - not being able to copy and use what printed
13:56	rhickey	i.e. it should only be in the render, not the text, so ask the Vi/emacs/enclojure guys...
13:56	tomhickey	rhickey: definitely. you would need IDE (render) level support for this, seeing as most output your looking at is monospaced anyways
13:57	rhickey	ah FORTRAN
13:57	abrooks	I may be in GCC and misremembering that as being in C99.
13:57	abrooks	rhickey: FORTRAN lives...
13:58	abrooks	Much of the code written by our customers is still FORTRAN.
13:59	abrooks	"But my keyboard doesn't _have_ a thin-space key!" http://groups.google.com/group/comp.lang.python/browse_thread/thread/93dc57f9190b93bc/a9adb78560888739?lnk=raot
14:01	abrooks	Oh, interesting. The X11 compose sequence MULTI+SPACE+SPACE is hair space.
14:01	abrooks	Or his it "thin" space. I can't tell.
14:02	abrooks	They don't look different. And /that/ really is the problem. They all look like space in a monospace font.
14:03	abrooks	And they look the same in the handful of proportional unicode fonts that I've checked.
14:04	abrooks	So, rhickey, how about those underscores?? ;-)
14:04	rhickey	yuck
14:04	abrooks	And thin/mini/tiny/hair/itsy-bitsy space is not yuck??
14:04	Chouser	no issues with infix notation, so how about dashes? 100-000-00
14:05	rhickey	please stop :)
14:05	abrooks	Chouser: If you're going to do numeric spaceing, stick with the semi-standard.
14:05	rhickey	really, I think this is an editor issue
14:06	Chouser	syntax-highlight sets of three digits in alternating colors?
14:06	rhickey	if you like
14:06	Chouser	I don't.
14:06	abrooks	Actually, just changing the background color of thin/hair space is probably good.
14:07	Chouser	Then again, I don't really have a dog in this hunt. So I'll stop talking now.
14:07	DrewR	Commas are already whitespace. How hard would it be to read int-comma-int before stripping them out?
14:07	DrewR	user> 23,000,000
14:07	DrewR	0
14:08	rhickey	DrewR: already playing with that idea
14:08	abrooks	DrewR: [1,2,3] ?
14:08	abrooks	I thought of that previously but ruled it out as it's an easy trap.
14:08	rhickey	abrooks: right, would refine the ws/comma rule
14:08	abrooks	[1, 2, 3,4] (oops)!
14:09	DrewR	Ugh.
14:09	abrooks	I like the comma as it is.
14:09	rhickey	who's writing [1,2,3,4]?
14:09	rhickey	oh
14:09	abrooks	Actually, I don't know that I ever have.
14:09	DrewR	I'll agree that there shouldn't be a difference between [1,2,3] and [1, 2, 3].
14:09	DrewR	That's just asking for trouble.
14:11	abrooks	0x239F,2B00,F269,BB14 doesn't look right. 0x239F_2B00_F269_BB14 does.
14:12	abrooks	The problem is that when looking at code, I parse "," as a list of things: 100_238_998 in my mind is a single number. 100,238,998 looks like three numbers.
14:12	DrewR	If I say, "java -jar start.jar" how does java know what main() to execute?
14:12	DrewR	Inside start.jar, obviously.
14:15	Chouser	The mainfest file has a Main-Class line
14:15	DrewR	mainfest! All main() all the time!
14:15	Chouser	DrewR: http://java.sun.com/docs/books/tutorial/deployment/jar/appman.html
14:15	DrewR	(Thanks, Chouser.)
14:16	Chouser	heh. sorry.
14:17	abrooks	BTW, neither the thin space nor hair space work at the repl.
14:18	rhickey	1'000'000'000
14:18	Chouser	this is a fun conversation
14:19	rhickey	0x239F'2B00'F269'BB14
14:19	Chouser	1:000/000*000
14:19	Chouser	oh, sorry, / is taken
14:19	abrooks	(println 1 '000' 000) (println 1'000'000)
14:20	rhickey	'000' ?
14:20	abrooks	' is interesting, but I think _ is more common. Is there any particular reason to reject the more common _?
14:20	Chouser	underscores are icky
14:21	abrooks	rhickey: I was trying to show that a spacing error can cause a semantic change.
14:21	rhickey	but '000' would have to be meaningful first
14:22	abrooks	Isn't it a string?
14:22	rhickey	[1 2 3 4] [1234]
14:22	rhickey	no, "000"
14:22	abrooks	Oh, is ' whitespace now?
14:22	abrooks	That might be fine with me.
14:22	Chouser	' only has meaning at the begining of token
14:22	Chouser	(quote ...)
14:22	rhickey	spacing errors often cause a change in Lisps, since the language is space delimited
14:23	abrooks	Chouser: Right.
14:28	rhickey	, could change from ", is whitespace" to ", is ignored" - if people are doing 1,2,3,4 or a,b,c,d in Lisp that's ugly
14:29	rhickey	but thousands sep is super low priority for me
14:57	StartsWithK	hi
14:57	StartsWithK	i am having problems with new 'ns' function
14:58	Chouser	hi? what's wrong?
14:58	Chouser	er. "hi!"
14:58	StartsWithK	i have one file with code (create-ns 'neman.ufo) (ns neman.ufo) (clojure/refer 'clojure :exclude '(new))
14:58	StartsWithK	if I load it from repl it works fine
14:59	Chouser	I don't think :exclude '(new) is going to do anything. But that may not be your point...
14:59	StartsWithK	now i have another file (create-ns 'neman.web) (ns neman.web (:require [neman.ufo :as ufo])) (clojure/refer 'clojure :exclude '(print println))
14:59	StartsWithK	i have my own 'new'
14:59	StartsWithK	in ufo namespace
15:00	StartsWithK	now when i call neman.ufo from another file i ger
15:00	StartsWithK	get*
15:00	Chouser	new is a special form, not a member of the clojure namespace.
15:00	StartsWithK	clojure.lang.Compiler$CompilerException: ufo.clj:11: Unable to resolve symbol: create-ns in this context
15:00	StartsWithK	but that special form is in clojure namespace
15:01	StartsWithK	it worked before i upgraded to new 'ns' function
15:01	StartsWithK	so is '.' in clojure, no problem defining my own :)
15:01	StartsWithK	this didn't happen before last upgrade and switching from contrib.lib to 'ns'
15:02	StartsWithK	so problem is when i have one file that has create-ns that refers to another file that has create-ns
15:03	Chouser	yeah, ns doesn't really work very well if you want to muck around with your (refer 'clojure).
15:04	Chouser	it's being worked out -- a patch is submitted and being mulled over, I think.
15:05	Chouser	your problem is that ns currently generates a few commands that expect some of clojure to be refer'ed already, but the way your pair of files is set up thay may not have happened.
15:05	StartsWithK	heh, i shoud stay away from trunk :)
15:06	Chouser	well, you should be able to in-ns, require, and refer from boot.clj (no lib.clj needed).
15:07	StartsWithK	yes, i removed lib.clj and started to switch.. no lib.clj in code anymore
15:07	Chouser	I think you may still be able to use ns ... mulling...
15:08	Chouser	oh, what if you just say clojure/create-ns in both files?
15:08	Chouser	instead of just create-ns
15:08	StartsWithK	i removed (create-ns) from file that refers to ufo.clj, that works
15:08	StartsWithK	clojure/create-ns or/and clojure/ns have no effect
15:08	StartsWithK	but now i dont have web/print :)
15:10	StartsWithK	also, why :require [bla :as ble] and :import (pkg Class), vectors for require and lists for import?
15:12	StartsWithK	oh, and could we have :import (org.mortbay.jetty Server .. (handle AbstractHandler ..) (nio SelectChannelConnector))
15:12	StartsWithK	so there would be no need to do org.mortbay.jetty org.mortbay.jetty.handler org.mortbay.jetty.nio ..
15:12	Chouser	I think that last suggestion was already made and rejected as too complex
15:13	StartsWithK	i see
15:14	Chouser	hm, I'm getting different error for you example because my Clojure's already patched.
15:14	StartsWithK	is it in trunk?
15:14	StartsWithK	ill pull
15:14	Chouser	ah, there we go.
15:15	Chouser	no, my patch is local. rhickey didn't like it quite as-is.
15:16	Chouser	ok, using clojure/create-ns and clojure/ns in ufo.clj works for me.
15:18	StartsWithK	it work for me too if i (load-file "src/neman/ufo/ufo.clj") from repl
15:18	Chouser	I'm pretty sure ":exclude '(new)" is a no-op, so all you really need in ufo.clj is just (clojure/ns neman.ufo)
15:18	StartsWithK	but if there is another file that has (create-ns 'foo) (ns foo (:require [neman.ufo :as ufo))
15:18	StartsWithK	then it breaks
15:19	Chouser	right. I'm loading web.clj, which enters the neman.web namespace (before refer'ing clojure there), and then loads ufo.clj.
15:20	Chouser	when run that way, ufo.clj starts off in neman.web with no clojure refer'ed, so you have to say clojure/create-ns and clojure/ns in ufo.clj
15:21	StartsWithK	java.lang.Exception: Unable to resolve symbol: import in this context
15:21	StartsWithK	clojure.lang.Compiler$CompilerException: ufo.clj:12: Unable to resolve symbol: import in this context
15:22	StartsWithK	(clojure/create-ns 'neman.ufo)
15:22	StartsWithK	(clojure/ns neman.ufo
15:22	StartsWithK	(:import (java.util UUID)))
15:22	StartsWithK	(clojure/refer 'clojure :exclude '(new))
15:26	StartsWithK	(clojure/create-ns 'neman.ufo)
15:26	StartsWithK	(clojure/refer 'clojure)
15:26	StartsWithK	(clojure/ns neman.ufo
15:26	StartsWithK	(:import (java.util UUID)))
15:26	StartsWithK	(clojure/refer 'clojure :exclude '(new))
15:26	StartsWithK	works if I add another (clojure/refer 'clojure)
15:27	StartsWithK	but it looks funny
15:28	StartsWithK	no.. not working, now if i uncomment my print and println in web.clj i get that they refer to clojure/print and clojure/println
15:33	ppjt	Hi all. Anyone played with compojure recently?
15:41	rhickey	anyone else bothered by plural-ness of defns?
15:41	kotarak	not me. But I see that there might be some potential for confusion.
15:42	abrooks	rhickey: Is that def+ns ?
15:42	rhickey	abrooks: yes
15:43	abrooks	Otherwise I might suggest def-ns. :)
15:43	rhickey	no other defs have -, so starting to use them now will leave people wondering in every case
15:44	abrooks	Well, there's defn-
15:44	abrooks	But that's differnt.
15:45	rhickey	right
15:45	abrooks	It's also different.
15:45	rhickey	alternatives welcome for the next 10 minutes
15:45	abrooks	def'ns
15:45	rhickey	very funny
15:46	abrooks	I'm sorry. I'd ACTUALLY contribute if I were able to think clearly today. Of course if I could think clearly, I'd be doing work, not hanging out here...
15:47	StartsWithK	defns will be used instead of create-ns?
15:47	DrewR	abrooks: That's cold.
15:48	abrooks	Oh, shoot. No, It's not a slam. I WANT to hang out here. I just have lots of stuff to do.
15:48	abrooks	DrewR: --^
15:48	ozzilee	ppjt: I've played with compojure recently.
15:48	DrewR	abrooks: :-)
15:51	abrooks	rhickey: I know it's a bit different (and I've really not seen much of any of the recent ns details) but what about: nsdef ?
15:52	rhickey	abrooks: not verby enough
15:52	abrooks	Or actually, ns-def since we already have ns-name, ns-interns, etc.
15:52	kotarak	It would invert the usual defn, defmethod, etc.
15:52	rhickey	ns-blahs are accessors
15:52	abrooks	Yeah, I'm slowly realizing that. Good point.
15:53	ozzilee	What wrong with (lib foo.bar.mylib) ? I'm looking at the mailing list archives but I'm not clear on that.
15:53	kotarak	how about defnamespace? It's a bit longish, but we have also defmethod...
15:53	rhickey	kotarak: one might wonder why it is ns in all the other functions
15:54	rhickey	setup-ns?
15:54	Chouser	mkns
15:54	Chouser	where mk is short for multi-key. sorry, nevermind.
15:54	rhickey	you guys are too much today :)
15:55	kotarak	How does one pronounce mkns? ;) Similar to Skrnjk. (<- That's actually a name.)
15:55	kotarak	make-ns?
15:55	abrooks	newns
15:56	Chouser	I like how declaritive defns is.
15:57	abrooks	I guess defns is the best though you know every new Clojure programmer will trip on that twice when the first learn Clojure.
15:57	Chouser	...compared to setup-ns, make-ns, mkns, etc.
15:57	Chouser	abrooks: how, by assuming it's plural of defn when they read code?
15:57	hoeck_	but defns sounds much like the plural of defn
15:57	abrooks	Chouser: Yes.
15:58	Chouser	init-ns, initns
15:58	abrooks	Chouser: Of course I have no idea what this will look like since I've not seen defns yet.
15:58	Chouser	defns will look like ns does now
15:59	abrooks	Oh, this is a rename of ns?
15:59	abrooks	Drat. I was just about to suggest plain "ns".
15:59	Chouser	(defns net.n01se (:refer-clojure ...) (:import ...))
15:59	kotarak	init-ns or make-ns or setup-ns are all ok for me. Although I like defns for the consistency for the other defs...
16:00	Chouser	well, if ns becomes defns, the new ns will be almost identical to in-ns.
16:00	rhickey	Chouser: right, just a macro shim
16:00	Chouser	So one option would be to leave ns as it is, and if you want to re-enter an existing namespace, use (in-ns 'foo)
16:01	Chouser	or rename in-ns to something longer and make in-ns the macro shim.
16:06	Chouser	I think the most common case will be one file per namespace, so to have a declaritive (ns ...) at the top seems nice. Then other files or at the repl you could say (in-ns ...) which could come to imply the namespace already exists and is set up.
16:21	ppjt	ozzilee: thanks. Stupid question, then -- do you know the canonical way to load one's own code from the app/ directory? There was a bit in the compojure docs about config/boot.clj loading any *.clj file under app/, but clearly that's not happening.
16:22	ozzilee	ppjt: Heh, nope, I've got no idea. I just added a line a boot.clj to load my files under app/
16:23	ppjt	ozzilee: Did you glob somehow, or just call load-file on some, etc.?
16:23	ozzilee	ppjt: Just called it on the file directly.
16:24	ozzilee	ppjt: I'm not particularly enamored of the layout myself, I'd prefer it if compojure was just a library I could load and use.
16:25	ppjt	ozzilee: Okay, thanks. I haven't yet digested the new namespace infrastructure, so I'm a little uncertain of how to do it correctly, or in a way I won't regret once I study up...
16:26	ozzilee	ppjt: Yeah me either. I've just been hammering stuff together, figuring it's all going to be evolving anyway.
16:26	ppjt	ozzilee: right, as is happening while we speak!
16:27	ozzilee	Indeed.
16:28	ppjt	ozzilee: file layout aside, d'you have any luck with compojure? Superficially, at least, it seems further along & more ready than another web framework I've happened across -- webjure.
16:28	ozzilee	ppjt: Yeah, I think webjure's dead. Compojure seems to work fine, I don't have anything in production on it though. I've been using it to screw around with Comet and CouchDB.
16:37	ppjt	ozzilee: Okay, cool. Myself, I'm just looking for an easy way to put clojure functions at the other end of HTTP requests, & that's its reason for being. So I shd be good. Don't know Comet; off to Wkp. Thanks!
16:37	ozzilee	ppjt: np
16:39	StartsWithK	ppjt: just looked at compojure, looks nice and simple to use
16:40	StartsWithK	i have something similar, but is much limited than that
16:40	StartsWithK	why didn't you write is as a lib?
16:42	ppjt	StartsWithK: yup, simply running script/repl & being ready to roll is a nice way to get acquainted
16:42	ppjt	StartsWithK: "write it as a lib" -- you mean the so-called app part?
16:42	StartsWithK	yes
16:43	StartsWithK	i have web.clj, design is copied from werkzeug (python lib)
16:43	StartsWithK	just needs to be refered
16:43	ppjt	StartsWithK: sorry to say I'm not exactly sure what that means -- make its own ns, load multiple resources, etc.?
16:44	ozzilee	StartsWithK: ppjt didn't write Compojure, if that's what you're thinking...
16:44	StartsWithK	it looks like i have to include my code inside your boot.clj or something?
16:44	StartsWithK	ups, sorry
16:44	StartsWithK	:)
16:45	StartsWithK	so ozzilee your the author?
16:45	ozzilee	Not me: http://github.com/weavejester/compojure/tree/master
16:47	StartsWithK	heh, files didn't have any copyright notice so i didn't catch authors name
16:47	ppjt	right, no, not me -- arohner, who's been active on the clojure group mailing list...
16:49	ppjt	he's done a nice job; & he's keeping up with the clojure head (added the new (ns) methods, e.g.)
16:50	ppjt	StartsWithK: ozzilee & I were just discussing how best to load your own code
16:50	StartsWithK	i tried to do the same, but my need are limited to serving json
16:50	StartsWithK	so no html generation and such
16:51	ppjt	we've both just (load-file)'d our app/*.clj files
16:52	ppjt	Would it seem to heavyweight even if you eliminated the libs (under lib/compojure) you didn't need?
16:53	StartsWithK	i don't have problem with extra code
16:53	wwmorgan	is there a reason that (prn #"foo") outputs foo and not #"foo" ?
16:57	ppjt	wwmorgan: #"foo" is a reader macro for a regex pattern
16:57	StartsWithK	wwmorgan: #"foo" will create java.util.regex.Pattern, i think prn will use Patten.tostirin
16:58	rapido	http://www.enchiladacode.nl. another language that has immutability at its core and sits on a jvm
16:58	rapido	the documentation is still a little bit rough and unfinished
16:59	DrewR	Oooh, browser-based REPL. rhickey better get right on that.
16:59	abrooks	It looks like enchilada is interpreted -- it's running in an applet.
17:00	abrooks	DrewR: You'd have to give up JVM bytecode compilation.
17:00	rapido	DrewR: i nicked the browser-based REPL from http://will.thimbleby.net/misc/
17:00	StartsWithK	abrooks: why?
17:00	DrewR	"Economical: no need for all those parenthesis." What's wrong with parens?
17:01	rapido	DrewR: it forces you to use shift 9 and 0 a lot! :)
17:01	DrewR	rapido: Not with a decent editor. :-)
17:02	DrewR	rapido: This is interesting. Thanks for posting.
17:02	rapido	DrewR: to be honest, to use enchilada you need a lot of parenthesis: squared, brackets, etc.
17:03	abrooks	StartsWithK: In order to run JVM bytecode that you've generated you need an alternate loader. The applet loader is one of the main security mechanisms of applets so you can't run created bytecode.
17:03	abrooks	The bytecode needs to be part of the original signed jar for an applet.
17:03	StartsWithK	abrooks: i have clojure applet for a month now
17:04	abrooks	An interpreter could be added to clojure but that would.. wha????
17:04	StartsWithK	http://kreso.moo.com/gears.html
17:04	abrooks	StartsWithK: Okay.. how?
17:04	StartsWithK	gears version in clojure
17:04	abrooks	StartsWithK: I'm not able to resolve kreso.moo.com
17:04	StartsWithK	abrooks: i am lazy, i promissed month ago to write up how to do it
17:05	StartsWithK	http://kreso.mooo.com/gears.html
17:05	StartsWithK	it works on xp with java and i think 32-bit linux if java is configured
17:05	kotarak	Say I do: (let [[f-lines r-lines] (split-with some-pred (line-seq some-rdr))] (process f-lines) (process r-lines)) Are the f-lines loaded completely into memory or only as I process them or access r-lines?
17:05	abrooks	StartsWithK: Ah, you provide a separate signed loader, right?
17:07	StartsWithK	abrooks: no, i just added all persmission to my applet, (there is small base java class, same as the one used for web start clojure app that is presented on google groups)
17:07	StartsWithK	uff.. me and my english :)
17:07	abrooks	StartsWithK: Cool -- It's running on x86_64 Linux in a 32-bit FireFox / Sun Java 1.6.
17:08	abrooks	StartsWithK: That's awesome. I really have to catch up with everything that's been going on with Clojure.
17:08	StartsWithK	http://kreso.mooo.com/ has some other examples
17:09	StartsWithK	so, who has swing repl code :)
17:09	abrooks	There is some IIRC.
17:09	abrooks	Hm. Maybe I'm thinking of the class browser.
17:12	rapido	enchilada treats code (and continuations) as immutable data
17:12	Chouser	I'm just now comfortable with lisp syntax. I'm not ready for postfix.
17:12	rapido	as such it is very hard to compile enchilada to the metal
17:12	StartsWithK	i was thinking of using http://prefuse.org/ to implement something like clojure.inspector in applet, but.. time is not on my side
17:14	rapido	Chouser: it is just syntax
17:15	rapido	although prefix would be more 'compatible' with lisp
17:15	Chouser	but syntax matters
17:15	rapido	Chouser: i hear you, but isn't this exactly why people don't like lisp? because of the syntax?
17:16	abrooks	I've written enough postscript to know that postfix notation fricks with my head.
17:16	rapido	(+ (+ 1 2) (+ 3 4))
17:16	rapido	or + + 1 2 + 3 4
17:16	rapido	or 1 2 + 3 4 + +
17:16	StartsWithK	well i can scan first, but not second or third (clojure is my first lisp)
17:16	kotarak	or (+ 1 2 3 4)
17:17	rapido	kotarak: yep, you can't have variable arguments in enchilada
17:18	rapido	only unary and binary operators
17:18	Chouser	having to keep the argument stack in my head while reading postfix is -- uncomfortable.
17:19	rapido	but is the (operator arg1 arg2 arg3 ...) idiom much used in lisp?
17:19	Chouser	1 2 3 4 5 + / * /
17:19	rapido	Chouser: don't think stacks. think term rewriting
17:19	rapido	and things get i little bit more convenient
17:20	Chouser	rapido: yes, arities of more than 2 are common in Clojure.
17:20	rapido	by the way, you can have postfix lambdas
17:20	Chouser	and for what it's worth, clojure has a bit more syntax than other lisps, and is more comfortable for me as a result.
17:21	Chouser	I imagine there are many people who would be less bothered by postfix than I am. :-)
17:21	rapido	4 5 + rewrites to 9. so replace 4 5 + with 9
17:22	rapido	Chouser: i have chosen for postfix because of the property that concatenating expressions syntactically yields valid expressions
17:24	rapido	a lot of enchilada magic comes from the combining of postfix expression in various ways
17:25	Chouser	interesting. Do all functions really take exactly 1 or 2 args?
17:25	rapido	yes
17:26	rapido	but you can create expression dynamically
17:26	kotarak	I'm not sure, whether I get the idea. 4 5 + f -> 9 f -> something. What is the difference to f + 4 5 -> f 9 -> something?
17:26	rapido	for instance: [1;2;3;4] [5;6;7;8] \| [] yields
17:26	rapido	[1;2;3;4] [5;6;7;8] \| []
17:26	rapido	yields: [1 5 ;2 6 ;3 7 ;4 8 ]
17:28	rapido	kotarak: if enchilada was impure, then term rewriting would have this equational property
17:29	rapido	kotarak: other than that, it is just about syntax
17:29	rapido	would <- would not
17:31	rhickey	rapido: I missed the beginning of this thread - was there a Clojure aspect originally?
17:31	rapido	rhickey: like clojure, enchilada has immutability at its core and is built on top of a jvm
17:32	rapido	other than that, i'm afraid there is no resemblance
17:34	rapido	i am a great supporter of clojure because it has immutability as the default
17:35	rapido	enchilada is more radical in that everything is immutable
17:35	kotarak	As in Haskell?
17:35	rapido	that said, it is a research language. my goal is to see how far you can go with immutability
17:35	rapido	kotarak: unsafePerformIO?
17:37	rapido	kotarak: and haskell doesn't have call/cc nor does it treat code as data
17:37	kotarak	Don't know much about Haskell. Just some basics. But unsafePerformIO sounds like the dark side.
17:37	kotarak	rapido: Does it need call/cc or does it have to tread code as data?
17:37	kotarak	s/tread/treat/
17:38	rapido	enchilada can be compared to 'pure lisp': http://en.wikipedia.org/wiki/Lispkit_Lisp
17:39	kotarak	It was my understanding, that Haskell does use the IO monad stuff, to work around the immutability because you get the "world" as a parameter. But this is maybe some naive view. As I said: still learning.
17:41	rapido	kotarak: alternatively, in clojure, you could pass the world in a immutable structure like vector or hashmap, instead of using monads
17:44	Chouser	Clojure specically doesn't pretend the world is immutable. Instead it makes it easy to manage that mutability well.
17:44	rapido	remember, you can 'change' worlds MVCC style
17:44	rhickey	rapido: then everyone takes turns for their turn with the world, Clojure's reference and agent sets are essentially worlds with better concurrency
17:45	rapido	rhickey: no need to take turns. everyone can create new worlds
17:45	rapido	and merge worlds to reach consensus
17:46	rhickey	merge is same problem
17:46	rhickey	single coordination point
17:46	rhickey	not practical
17:46	rhickey	doesn't scale
17:46	rapido	rhickey: no, it does scale much better than locks
17:47	rapido	look at git
17:48	rapido	you can reach consensus with different merging strategies, and optimistically
17:48	rapido	let's say n threads create n worlds
17:49	rapido	then 0.5n threads pair up independently and concurrently to merge their worlds
17:50	rapido	after that 0.25n threads pair up,... etc until consensus is reached
17:50	rhickey	all that consensus is coordination
17:50	rhickey	having a single world makes for larger-than-needed granularity
17:50	rapido	sure
17:50	rhickey	split upt the world and essentiall you've got Clojure's refs
17:51	rhickey	assoc == merge
17:51	rhickey	commute etc
17:51	rhickey	fine granularity
17:51	rhickey	coordinate only on conflict
17:52	rhickey	I doubt you could put GIT's system into in-proc and compete with STM
17:52	rhickey	without it becoming STM
17:52	rapido	rhickey: but git would compete pretty good with distributed databases
17:53	rapido	enchilada is more in the 'distributed database' hemisphere than in the 'multi core' hemisphere
17:54	rapido	although enchilada gains some speed on multi cores because it is multi threaded
17:54	rhickey	I looked into DHT at your suggestion and didn't find anything with fine enough granularity to be a distributed DB - all had document granularity, lots of caveats etc
17:55	rhickey	transaction in particular are a problem
17:56	rapido	rhickey: it is true that DHTs are document centric, but why do you need transactions?
17:58	rhickey	because that's how systems work - n-operations constitute one unit of work, the classic bank-account transfer problem etc
17:59	rhickey	RDBMS, Mnesia, Scalaris - all recognize that need, not a DB without it
18:00	rapido	but you can't you do transactions on top of MVCC and immutable structures?
18:01	rapido	the only thing you need is the durability (D) guarantee
18:01	rhickey	Distributing it is the problem
18:01	rhickey	Postgresql and Oracle are MVCC
18:02	rapido	rhickey: are you referring to two phase commit?
18:03	rhickey	That's one technique, Scalaris has quite another
18:03	rhickey	I'm not writing a distributed DB
18:04	rhickey	Clojure's STM could most easily get distributed with something like Terracotta
18:06	rhickey	The only thing non-overlapping STM transactions share is a single timestamp, which is just a CAS in-proc, but difficult to scale on the wire
18:07	rapido	rhickey: let me point you to a database that uses immutable structures: http://www.herodotus.biz/DB_Features.html
18:08	rapido	i believe it is used for GIS applications. According to GIS the world is constantly changing! :)
18:10	rhickey	I'm not what that means in the case of DBs - any MVCC makes the past seem immutable, it's simply a matter of how much of it you keep around.
18:11	rhickey	or more specifically, online, since everyone logs their DB
18:11	rhickey	update is not in the relational model
18:12	rapido	rhickey: herodotus doesn't use a log. you can jump instantly to the past and compare the past with other versions
18:13	rapido	log transacted databases don't scale: the log will alway be the bottleneck
18:13	rhickey	that's my point, they keep more online, but at some point that's impractical and you want something like GC, or spool off, these are all differences of degree, not kind
18:13	rapido	alway <- always
18:16	rapido	but log transacted databases are a different kind than databases such as herodotus
18:16	rhickey	not really
18:18	rapido	throwing away history is easy
18:19	rapido	jumping back in history is not
18:19	rhickey	keeping it online is expensive, especially when it comes to indexing and queries
18:21	rapido	rhickey: that's why i have built enchilada: to show that keeping history (indexes, queries) can be done relatively 'cheaply'
18:21	rhickey	many times you use a table in 'append-only' mode, even in a RDBMS, but it's a choice you make trading off the query perf for the history
18:23	rapido	rhickey: i know what you are saying: i work at a bank. we keep lots of (time-series) history. :)
18:23	rhickey	don't get me wrong, I love the idea of keeping everything, but there are tradeoffs with keeping it online
18:24	rapido	at the bank we are not allowed to throw away data because of SOX compliancy rules
18:24	rapido	what to do? :)
18:25	rapido	rhickey: good to know you like to keep things too.
18:26	rapido	rhickey: it has been nice chatting to you... i have to run.... later