#clojure – 2011-05-08

2011-05-08

01:03	TheMoonMaster	STM is amazing.
04:20	kzar	Can you perform dynamic method calls without creating a macro?
04:41	thorwil	kzar: do you mean somehow arriving at the name of a function as a string, then call it?
04:43	kzar	thorwil: Well I have my keyword :insert , I've changed it to the symbol .insert fine. But then when I call it (thing-containing-.insert object) it doesn't work. I (sort of) get why, the dot form is evaluated at compile time so I'm going about it the wrong way?
04:46	thorwil	no idea how the java-interop might screw you there. i mean, with foo.method, i don't know if that shouldn't be though of as one symbol
04:47	thorwil	guess an alternative to a macro might be eval
05:07	raek	kzar: (clojure.lang.Reflector/invokeInstanceMethod object "method name" (to-array [arg1 arg2 ...]))
05:13	raek	kzar: Also, if you do want to use a macro, it's probably easier to generate (. object method arg1 arg2 ...) rather than (.method object arg1 arg2 ...). The latter is syntactic sugar for humans.
05:17	kzar	raek: Ah right, actually which approach is more idiomatic?
05:18	raek	kzar: I would say that if you know the method name at compile time, there is no good reson to not generate (. object method ...) with a macro
05:19	raek	that will be compiled into a invokevirtual JVM bytecode instruction
05:20	raek	a reflective call will be far mor slower, but sometimes you simply do not know class+method until at runtume
05:22	kzar	Hmm if I'm honest I'm not sure if I do know the method name at compile time or not. I've got a bunch of actions for google calendar and for each one I have to call one of 4 methods, either .insert .update .query or .delete . So I could have a switch to say if it's type is :insert then do (.insert ....) for each of the 4 but I figured that was ugly
05:24	raek	kzar: so you want to be able to do someting like (foo :insert obj ...)?
05:25	kzar	raek: Yea pretty much I guess
05:27	thorwil	my first mail to the enlive group didn't go through for 2 days, then when i mailed again, both copies arrived immediately. now a reply on the second of them send about 11 hours ago did not appear so far :/
05:27	kzar	raek: I think I'm just going to use a case statement on the type keyword and make it easier on myself
05:27	raek	(case action :insert (.insert ...), :update (.update ...), :query (.query ...), :delete (.delete ...))
05:27	kzar	raek: Yep exactly! I'll try and be clever another day
05:28	kzar	raek: You see what I mean though, it feels like you should be able to go from :insert to (.insert object ..)
05:28	raek	if all the cases follow exactly the same pattern, it would be quite simple to do a (actions action [:insert :update :query :delete]) macro that expands to this
05:29	raek	kzar: any reason you don't want four separate defns?
05:29	kzar	how do you mean?
05:30	raek	(defn insert-fn [...] (.insert ...)) (defn update-fn [...] (.update ...)) etc
05:31	kzar	I guess because I've got a seq of actions and I don't know that they will all be the same type. I wanted to map over them running the same function
05:31	raek	kzar: how are you going to call the function that contains this case expression? always with a variable containing a unknown keyword or do you know the keyword?
05:32	kzar	raek: Just with a map, I could check the type of action in the mapping function though for sure
05:34	raek	something like this maybe? (def fn-map {:insert #'insert-fn, :update #'update-fn}) (map #((fn-map %1) %2) actions args)
05:35	raek	this is one way that closely fits the "to go from :insert to (.insert object ..)" description
05:36	raek	the case way would be fine too, I guess
05:37	kzar	raek: How about this, I map over the list of actions with a macro that generates the method calling code
05:39	raek	kzar: sounds good
05:40	raek	given that the method name is the only difference between the calls, of course
05:40	kzar	heh yea I'm hoping it is, if it turns out that's not the case I'll go back to using a function with a case statement me-thinks!
05:44	kzar	raek: Thanks for the ideas anyway, that was a puzzler
11:12	bartj	er, anyone with a machine learning background here ?
11:22	jamesswift	hey folks. question for those who have written some web apps in clojure. preferably with ring etc.
11:25	jamesswift	I am running my app with jetty as usual and then reverse proxying with apache. but was wondering what is the best strategy for dealing with the fact that the absolute path can be changed. issues include adjusting the routes (currently I do (str prefix "/my-route") and also I'm using enlive for templating, this brings problems where I need to reference css and js files. Usually one would keep a common css file in something like
11:25	jamesswift	"/css/"
11:28	jamesswift	So basically just wondering what solutions others have come up with to make this painless?
11:33	gfrlog	jamesswift: your prefix is the path with hostname?
11:34	gfrlog	(I just arrived, so I'm reading your comments from http://clojure-log.n01se.net/ and might be missing some)
11:38	jamesswift	gfrlog: i wrote a little wrapper which checks the incoming request to see if it's being x-forwarded and if so use binding to change prefix to the reverse proxy path I've set up in apache. if it's not being forwarded it remains an empty string.
11:39	jamesswift	gfrlog: all the comments are there. i probably should expand on the issue a bit.
11:40	jamesswift	gfrlog: i actually made a mistake in describing, sorry. apache reverse proxies don't change the uri so i don't change the route but i do have to change and redirects. so the prefix is only prepended to redirect URIs and not routes as I mentioned before.
11:41	jamesswift	gfrlog: i'll write up a code sample and pastebin it. back in 5 mins
11:41	gfrlog	jamesswift: apache is adding a prefix to your path? like a sub-uri?
11:47	jamesswift	gfrlog: Here is an example https://gist.github.com/46bd4b12e078864ccae0
11:48	gfrlog	I think if you have to have a path prefix, that might be essentially how to handle it. The only way I can think of to make it nicer is to create a url function so you aren't repeating (str prefix ...) everywhere.
11:48	jamesswift	gfrlog: I'm using mod_proxy so that I have my clojure app hosted at http://examplecom/some-virt-path but really it's running on localhost:8080 for example so Apache reverse proxies /some-virt-path to localhost:8080 without changing the uri path in the headers
11:49	gfrlog	when I was doing rails I started using subdomains instead of sub-URI's precisely in order to avoid this headache
11:50	gfrlog	subdomains are transparent since you don't have to include them in the links etc.
11:50	jamesswift	gfrlog: yeah that's the only strategy I can think of too. pity. the main headache comes with having to rewrite urls in the template pages that reference common stuff like css.
11:51	jamesswift	gfrlog: the apache docs do mention a third party mod which can rewrite urls in the response html but that feels wrong
11:51	gfrlog	jamesswift: I usually find myself creating a helper function for writing urls anyhow, so if you're used to that it's not that bad
11:51	gfrlog	jamesswift: I agree that's ugly
11:53	jamesswift	gfrlog: i suspect a rule at the top of every enlive template that matches all href and src values starting with '/' might be the simplest solution right now.
11:53	gfrlog	jamesswift: I use the helper function for when some resource's ID is going into the url, so I'm not messing with (str) or (format)
11:53	jamesswift	gfrlog: makes sense
13:13	dnolen	fascinating GHC 7 uses constraint solving for type inference, http://research.microsoft.com/en-us/um/people/simonpj/papers/constraints/index.htm, CHR lead co-wrote the paper.
14:31	fliebel	dnolen: oh, nice, so Haskel is an example of these 'al la carte' type systems?
14:33	dnolen	fliebel: no.
14:33	fliebel	dnolen: Okay, then what is the type system about?
14:34	dnolen	fliebel: the paper is how generalized let creates problems for type inference and their new (even controversial) approach, it's a big break from HM style type-inference.
14:43	dnolen	fliebel: it's yet another reason I would like to see an efficient constraint solver implementation added to core.logic. interestingly enough, efficient predicate dispatch might be useful here...
14:44	fliebel	i see…
14:44	Ramblurr	is there a function that is the opposite of 'take', i.e, get the _last_ n items in a coll?
14:45	Ramblurr	something like (drop (- (count coll) n)) coll)
14:45	kzar	Ramblurr: might be a better way but you could reverse it and then take the n items
14:45	Ramblurr	oh jebus, there is a take-last
14:46	kzar	ah cool, didn't know that :)
14:46	dnolen	fliebel: maybe next year Clojure will have state-of-the-art optional static typing ...
14:46	Ramblurr	kzar: yea, found it via clojuredocs.org's "See Other" feature
14:47	fliebel	that'd be awesome, but how deep do you need to dig into clojure for that? or is it just a lot of typehints?
14:49	dnolen	fliebel: would need some kind of hook into data produced by the compiler, but it would be a very loose coupling.
14:49	fliebel	S I guess that's "waiting on the new compiler", together with some other cool stuff.
15:14	fliebel	Why does if-let not support multiple bindings? So that all bindings have an 'and' relation, with 'or' still being usable to let the first truthy case. (if-let [x true y (or false true)] [x y]) > true true
15:39	KineticShampoo	Hello
15:39	odyssomay	hello
16:30	KineticShampoo	Can someone explain what a 'higher order function' is in layman terms?
16:30	KineticShampoo	I found the term while searching for college assignments on Clojure to practice on.
16:30	KineticShampoo	http://www.cis.upenn.edu/~matuszek/cis554-2010/Assignments/clojure-01-exercises.html
16:31	KineticShampoo	ie "You don't need higher order functions"
16:31	Thorn	a function which acts on functions
16:31	kzar	KineticShampoo: It's a function that takes functions as arguments or returns functions
16:32	fliebel	&(partial + 1)
16:32	sexpbot	⟹ #<core$partial$fn__3678 clojure.core$partial$fn__3678@27291d>
16:32	KineticShampoo	kzar: Thanks! That's a simple explanation. :) So the function uses the returns values of another function, correct?
16:32	fliebel	In this case, partial takes a function, and returns a new function with the supplied args already provided.
16:33	fliebel	&((partial + 1) 1)
16:33	sexpbot	⟹ 2
16:33	kzar	(defn example [f num] (f num 10)) (example * 5) = 50 (example + 5) = 15
16:34	kzar	KineticShampoo: Yea it's all dead handy, partial is great too
16:35	Thorn	KineticShampoo: not just one that uses return values of another function. that would make most every C function higher order lol
16:35	fliebel	It's these kind of things that help writing a DSL, macros are pretty meh for most things ;)
16:35	Thorn	KineticShampoo: (defn f [a] (a 3 4)) (f +) ; takes a function (+) as an argument and applies it to 3 and 4
16:39	Thorn	or: (defn make-adder [b] (fn [a] (+ a b))) ((make-adder 3) 7)
16:43	KineticShampoo	When I first tried Clojure on a VM I used Eclipse and I remember it having a plugin that I assume automatically installed everything for me.
16:43	KineticShampoo	Now I installed Ubuntu 11.04 and want to use Geany as my editor. So without Eclipse, how can I install Clojure? Googling has lead me to believe that the only way is to git pull from the repo on github.
16:44	maacl	This https://gist.github.com/961679 solves http://www.4clojure.com/problem/62 at my REPL but 4clojure claims wrong no. of args to comp - any ideas?
16:44	pdk`	you just need to have the two jars for clojure and clojure-contrib
16:45	pdk`	have them in your classpath and you're golden
16:45	fliebel	KineticShampoo: Have a look at Leiningen too
16:45	KineticShampoo	Is this the standard way?
16:46	fliebel	Most people use lein or cake. managing the classpath and jars yourself is uncool imo.
16:47	Thorn	maven it standard in the java world, but it downloads half of the internet on the first run
16:48	fliebel	And a tenth of the internet on each subsequent run
16:49	Thorn	*is
16:55	fliebel	Why does if-let let into a temp var and then in the truth case into the real var? Does it hurt anyone to let it right away?
16:56	fliebel	when-let is even weirder, since there is no false case.
16:58	kzar	I have (:import [java.net URL]) in my ns declaration and it was working fine until I had to restart my Clojure process. It's giving me "Unable to resolve clasname: URL" now though :o any ideas?
17:05	maacl	Has previous versions of Clojure had issues with (apply comp '()) ?
17:08	fliebel	&(comp)
17:08	sexpbot	java.lang.IllegalArgumentException: Wrong number of args (0) passed to: core$comp
17:09	fliebel	maacl: What issues?
17:09	maacl	&(apply comp '())
17:09	sexpbot	java.lang.IllegalArgumentException: Wrong number of args (0) passed to: core$comp
17:10	fliebel	&(apply comp identity '()) ; this might be what you want
17:10	sexpbot	⟹ #<core$identity clojure.core$identity@1c22e0d>
17:11	maacl	It evals fine at my REPL using 1.3.0-alpha5
17:11	fliebel	maacl: What does it do?
17:12	fliebel	Oh, i see, just what I just typed.
17:12	fliebel	it returns identity
17:12	maacl	yes
17:12	brehaut	,()
17:12	clojurebot	()
17:13	brehaut	fliebel: you dont need to quote the empty list
17:13	fliebel	brehaut: Oh, nice to know :)
17:13	brehaut	i keep forgetting too :)
17:13	maacl	So the behavior must have changed at some point?
17:14	fliebel	maacl: yes, it must, unless we got all rolled up in a time continuum.
17:14	fliebel	But my identity hack works around it, if you must support both.
17:14	maacl	fliebel: well, you never know
17:15	maacl	fliebel: yes, thanks
17:25	KineticShampoo	hm.
17:29	gfrlog	KineticShampoo: yep.
17:33	ekoontz	hey, question about mapcat..
17:33	ekoontz	https://gist.github.com/961694
17:34	ekoontz	how would i do that if i wanted to pass an additional param to cook-kids
17:37	tomoj	mapcat is just like map in that way ##(mapcat #(list %1 %2) [1 2 3] [4 5 6])
17:37	sexpbot	⟹ (1 4 2 5 3 6)
17:37	ekoontz	##(mapcat #(list %1 %2) [1 2 3] [4 5 6])
17:37	sexpbot	⟹ (1 4 2 5 3 6)
17:37	ekoontz	thanks a lot tomoj :)
17:37	ekoontz	makes sense..the googles they did nothing
17:39	ekoontz	*cool-kids not cook-kids lol
17:40	KineticShampoo	##mapcat #(list %1 %2) [1 2 3] [4 5] [6] [7 8 9])
17:40	KineticShampoo	##mapcat #(list %1 %2 %3 %4) [1 2 3] [4 5] [6] [7 8 9])
17:41	ekoontz	thanks KineticShampoo
17:43	tomoj	of course #(list %1 %2) is a bit silly
17:43	brehaut	ekoontz: also if you are using mapcat it may be that for would be cleaner
17:44	ekoontz	brehaut: i see, thanks, tho it took me a while to parse your sentence :)
17:45	brehaut	ekoontz: sorry about that, i should have quoted the funs. i cant get to your gist at the moment so i dont know if its relevant, but 'for' is list comprehensions, which is just sugar over the list monad and mapcat is bind in the list monad
17:46	ekoontz	i am still strugging with the clojure syntax
17:46	ekoontz	use to (mapcar #'(lambda(x) ...)
17:46	ekoontz	*used
17:47	tomoj	was your example just for playing around with mapcat?
17:48	ekoontz	yeah let me try pastebin
17:49	ekoontz	sorry having pastebin problems too lol
17:49	brehaut	my internet is just extremely slow ATM
17:49	brehaut	i cant get to anything ;)
17:49	ekoontz	http://pastebin.com/FGAaq1uc
17:49	ekoontz	are we in the same cafe? ;)
17:51	tomoj	example seems strange for mapcat
17:52	raek	ekoontz: #' means something else in clojure. functions and variables share the same namespace.
17:53	ekoontz	there's no #'lambda i guess right
17:53	raek	just use fn
17:53	raek	,(map (fn [x] (inc x)) [1 2 3])
17:53	clojurebot	(2 3 4)
17:53	brehaut	ekoontz: heres the correspondence: (for [a (range 3) b [:a :c]] [a b]) => (m-bind (range 3) (fn [a] (m-bind [:a :c] (fn [b] (m-return [a b]))))) => (mapcat (fn [a] (mapcat (fn [b] [[a b]]) [:a :c])) (range 3))
17:53	raek	,(map inc [1 2 3])
17:53	clojurebot	(2 3 4)
17:54	brehaut	(m-bind and mapcat take their args in reverse order)
17:54	ekoontz	thanks raek
17:54	ekoontz	ok..that makse sense
17:54	ekoontz	makes*
17:55	raek	ekoontz: your cool-kids example can also be written as (for [kid '(kurt bob tony), :when (= kid 'kurt)] kid)
17:55	brehaut	ekoontz: the middle form is very slightly pseudocode; it makes use of forms from the clojure.contrib.monads library
17:55	tomoj	but why?
17:56	ekoontz	brehaut: the middle form..?
17:57	brehaut	in the big block of nonsense i pasted above
17:57	ekoontz	like..never heard of (m-bind) before..
17:59	brehaut	ekoontz: thats 'just' monads stuff; im only using it to demonstrate the corrospondence; mapcat is fairly rare in clojure code because for is cleaner
17:59	brehaut	(most of the time)
17:59	brehaut	ekoontz: m-bind is a abstraction over function application
17:59	ekoontz	the word 'monads' scares me
17:59	brehaut	yeesh s/is a/is just an/
18:00	tomoj	ekoontz: so would you use mapcat or for to do exactly what your example does?
18:00	ekoontz	i keep hearing about it and still don't understanding it
18:00	ekoontz	i would use mapcat personally
18:00	tomoj	(that's a yes/no, not a mapcat/for question)
18:00	ekoontz	maybe because i don't know (for)
18:01	tomoj	how about ##(filter '#{kurt} '[kurt bob tony])
18:01	sexpbot	⟹ (kurt)
18:01	tomoj	I don't know whether the example was contrived for mapcat or whether that way was unknown
18:01	ekoontz	haven't heard of (filter) either
18:01	ekoontz	but it seems very intuitive :)
18:02	ekoontz	well i want to pass another param to the filtering function
18:04	gfrlog	ekoontz: you want to pass the first param or the second?
18:35	gfrlog	$findfn [7,8,9,10] 9 2
18:35	sexpbot	[]
18:35	gfrlog	$findfn 9 [7,8,9,10] 2
18:35	sexpbot	[]
18:36	gfrlog	:-\|
18:48	gfrlog	$findfn [4,5,6] 5
18:48	sexpbot	[clojure.core/second clojure.core/fnext]
20:22	sritchie	hey all -- is it possible class call some method other than -main inside of a namespace, when running java -jar my-standalone.jar my.ns arg1 arg2
20:23	sritchie	java -jar my-standalone.jar my.ns method-name arg1 arg2, for example/
20:25	tomoj	I don't think so, but you can have -main decide to call other functions
20:26	tomoj	`man java` says it looks for public static void main(String[] args) and that's it
20:30	sritchie	tomoj: that makes sense, I could get the same behavior by using the first argument as input to case
20:31	sritchie	thanks
20:32	tomoj	guess the problem is if you want to support passing a method-name and not, how do you tell whether it's method-name or arg1?
20:35	gfrlog	his default case would decide that it's arg1?
20:40	tomoj	sure, but if you ever want to pass an arg1 that happens to have the same name as some function in the namespace..
20:40	gfrlog	no way out of that
21:28	KineticShampoo	FINALLY!
21:29	KineticShampoo	Finished this project tasks I had with my school software.
21:29	KineticShampoo	Now I can focus on some Clojure. Problem is I don't really know what to make with the language. Any beginner exercises you would recommend? Something to get me thinking in Clojure?
21:29	gfrlog	man some folk just set up a site for exactly that
21:29	gfrlog	it probably had a catchy name too
21:30	gfrlog	one sec I can find it...
21:30	KineticShampoo	Google?
21:30	gfrlog	wouldn't know what to google for
21:30	KineticShampoo	If you say Google I'll slap you. No matter how many proxies you're behind.
21:30	gfrlog	4clojure
21:30	KineticShampoo	:D
21:30	KineticShampoo	Oh yeah, that's Raynes site.
21:30	gfrlog	right
21:31	gfrlog	not what you're looking for?
21:31	KineticShampoo	I used it, but while I can solve some of the problems I don't feel I'm learning; if that makes sense.
21:31	gfrlog	okay -- project euler then?
21:31	gfrlog	unless you hate math
21:31	KineticShampoo	I'm looking for a concrete assignment. The type you would get during first or second year Uni. (Yes I hate math! :D)
21:32	KineticShampoo	Is there something like Codingbat, but for Clojure?
21:32	gfrlog	I'm out of ideas. Best I can offer at this point is to think up something for you myself :)
21:33	KineticShampoo	Shoot for it. :)
21:33	KineticShampoo	Better yet, what book do you recommend for someone new?
21:33	gfrlog	okay. Write a web app that will make millions of dollars simply by virtue of the fact that it is deployed at the domain lolwaffle.com. I'll contribute the domain name and we can split the profits.
21:34	KineticShampoo	Can I use a visual basic gooey?
21:34	TheMoonMaster	Woah woah waoh, we aren't tracking IP's
21:34	gfrlog	huh?
21:34	tomoj	:D
21:35	TheMoonMaster	http://www.youtube.com/watch?v=hkDD03yeLnU
21:35	gfrlog	oh wait right
21:35	gfrlog	I should've caught that
21:36	gfrlog	KineticShampoo: my estimate is that the total number of clojure books is between two and three, inclusive.
21:36	TheMoonMaster	Macros are odd
21:36	gfrlog	TheMoonMaster: yep
21:36	KineticShampoo	LOL
21:36	TheMoonMaster	KineticShampoo: I'm reading Programming Clojure
21:36	KineticShampoo	Seriously? Only two books!?
21:36	gfrlog	KineticShampoo: I've only read one of them.
21:37	TheMoonMaster	http://pragprog.com/titles/shcloj/programming-clojure
21:37	gfrlog	KineticShampoo: ^ that was the one I read
21:37	TheMoonMaster	That is the only good one I know of.
21:37	gfrlog	it was like two years ago. I liked it.
21:38	KineticShampoo	I wish Raynes would hurry up with his book. It has a kiddie cover, it seems to be a good fit for newbies. Hehehehe
21:38	TheMoonMaster	In the beginning it does fairly well teaching the concepts, but at concurrency and macros it starts to fall behind imo.
21:39	gfrlog	TheMoonMaster: it sure taught me to avoid macros :)
21:39	TheMoonMaster	gfrlog: Yeah, prevent the whole, what the hell did I just code mentality...
21:39	gfrlog	I think only in the last six months or so have I started using macros goodly
21:39	tomoj	goodly! <3
21:39	TheMoonMaster	I really don't have much to program due to lack of creativity in that field, but clojure is nice so far.
21:40	TheMoonMaster	I mostly do web development, and unfortunately I don't like clojure for web stuff as much as I like Ruby for it.
21:40	gfrlog	TheMoonMaster: help KineticShampoo and you two can split his half of the million
21:40	TheMoonMaster	gfrlog: Sorry, but it would end up being made in rails.
21:41	gfrlog	but OOP is so sticky
21:41	tomoj	maybe the frontend
21:41	TheMoonMaster	Ruby OOP is nice.
21:41	tomoj	you want to write the entire backend in rails too? are you doing anything interesting? :)
21:41	KineticShampoo	Does Clojure have classes? Or just lists and maps?
21:41	gfrlog	KineticShampoo: it has some differenter things. It also has the plain java classes if you need them for something awkward
21:42	tomoj	oh, I didn't read the backlog, you don't have to do anything interesting with that domain name
21:42	gfrlog	tomoj: what do I need to do then, just add adsense?
21:42	TheMoonMaster	Haha, I can't thing of anything to do with lolwaffle.com
21:43	tomoj	I dunno, it was your idea?
21:43	gfrlog	as best I can tell
21:45	gfrlog	KineticShampoo: now that I think about it, there are probably like six or eight different parts of clojure that could be given as an answer to that question, depending on what you mean by "classes"
21:46	KineticShampoo	I mean them in the traditional POJO/POCO class context.
21:47	gfrlog	as I understand it, the clojure complaint about Java OOP is that it's a pile of different concepts mashed together when you'd prefer to have them separately and take only what you need
21:47	gfrlog	so for example some java classes (Utils?) are just collections of related methods. That's what clojure namespaces do
21:48	Raynes	KineticShampoo: Man, I wish I'd hurry up with my book more than you do.
21:48	gfrlog	if I were good at explaining this stuff, I would go on to list several other concepts. But it is too humid.
21:49	KineticShampoo	Raynes get to it! Stop trolling around the F# forums.
21:49	gfrlog	Raynes: I wish for more wishes
21:49	TheMoonMaster	Just saying, I hate macros right now.
21:50	Raynes	I've been trolling F# forums? :o
21:50	gfrlog	TheMoonMaster: what're you doing?
21:50	tomoj	I really like clojure's not having arbitrary object hierarchies built up between me and the data because I almost always know how to just get the damn data
21:50	Clinteger	Raynes you’re not done with that yet? D:
21:50	Raynes	I sure wish somebody would have told me this.
21:50	TheMoonMaster	gfrlog: Reading the macros chapter, wrapping my head around this isn't easy.
21:50	Raynes	Clinteger: Man, it takes time to write a book.
21:50	Clinteger	it’s ok :p i’m only joking, you’re busier than me and i’d still be writing chapter 1 :)
21:50	gfrlog	TheMoonMaster: oh. well then. Let me try putting it this way.
21:51	KineticShampoo	Free copies for DIC members with over 500 karma? :D
21:51	gfrlog	TheMoonMaster: a macro is a function that takes code and messes with it and outputs some other code
21:51	KineticShampoo	wink wink nudge nudge
21:51	TheMoonMaster	Yeah, I get that much
21:52	Raynes	KineticShampoo: Not a chance. I'll probably give away a few copies with some sort of contest though.
21:52	gfrlog	TheMoonMaster: okay. Well then, I already understand macros, so why on earth does that not lead directly to you understanding them?
21:52	TheMoonMaster	lol
21:52	gfrlog	TheMoonMaster: it seems so easy!!!
21:53	TheMoonMaster	Haha, this book just doesn't teach it in a way I understand easily I suppose.
21:53	TheMoonMaster	I'll get it eventually.
21:54	gfrlog	(defmacro with-clojure [& forms] `(do ~@forms))
21:54	TheMoonMaster	I do like the way Clojure does java integration though, that is pretty sweet.
21:55	TheMoonMaster	I have no idea what `(do ~@forms) even does
21:56	gfrlog	it does something like (cons 'do forms)
21:56	TheMoonMaster	I don't understand what `do does either.
21:57	TheMoonMaster	Sorry, I am super new to clojure
21:58	gfrlog	that's funny cause 'super' and 'new' are both keywords in Java
21:58	TheMoonMaster	Ohhhhhh, so the ` quotes the whole thing, and the ~ evaluates that and doesn't quote it!
21:58	TheMoonMaster	Haha, to be honest I really don't do much JAva
21:59	TheMoonMaster	I did Java for like a week last year for my AP CS exam in high school.
21:59	gfrlog	TheMoonMaster: yeah basically. There's an obvious and a subtle difference between ' and `
22:00	gfrlog	by which I mean not that the difference is both subtle and obvious, but that there are two differences, and one is subtle and the other is obvious
22:00	TheMoonMaster	Haha yeah
22:00	gfrlog	and the fact that they are two different characters is not either of them
22:01	gfrlog	the obvious difference is that ` allows unquoting, which you just observed
22:01	gfrlog	the subtle one has to do with qualifying symbols, and I refuse to elaborate due to cognitive limitations
22:01	TheMoonMaster	lol alright
22:02	gfrlog	` is used most often in macros because unquoting is so convenient
22:02	gfrlog	but you can use it anywhere
22:02	gfrlog	,`(I have ~(+ 3 4) piles of functions)
22:02	clojurebot	(sandbox/I sandbox/have 7 sandbox/piles sandbox/of sandbox/functions)
22:02	TheMoonMaster	Idiomatically do you use ` much outside of macros?
22:02	gfrlog	I don't think I ever have
22:03	gfrlog	nor seen it
22:03	TheMoonMaster	Didn't think so.
22:03	gfrlog	probably because of that obnoxious subtle difference that clojurebot just exhibited
22:03	TheMoonMaster	lol
22:04	amalloy	i use ` in functions when the functions are helper functions used by macros
22:04	gfrlog	amalloy: I'm trying to write some code to convert clojure functions to point-free versions. Does that sound stupid or awesome or like something that already exists?
22:04	TheMoonMaster	amalloy: I can see how that makes sense.
22:04	amalloy	because you don't (usually) break macros up into N smaller macros, you break them up into N functions and one master macro
22:05	amalloy	$google amalloy macro writing macros
22:05	sexpbot	First out of 38 results is: Clojure: macro-writing macros
22:05	sexpbot	http://hubpages.com/hub/Clojure-macro-writing-macros
22:05	amalloy	TheMoonMaster: ^ is my blog entry on it
22:05	gfrlog	$google amalloy babies having babies
22:05	sexpbot	First out of 86 results is: Dr. Stephen A. Malloy
22:05	sexpbot	http://www.rootsweb.ancestry.com/~ncccha/biographies/stephenamalloy/stephenamalloy.html
22:05	gfrlog	well that's enlightening
22:05	TheMoonMaster	Definitely bookmarking your site
22:05	amalloy	wth
22:06	gfrlog	sorry, I'm apparently in a strange mood tonight
22:07	gfrlog	hmm. that is a rather strange search result.
22:08	TheMoonMaster	lol
22:08	TheMoonMaster	So are clojure agents similar to Scala actors?
22:09	gfrlog	are scala actors similar to those erlang things?
22:09	TheMoonMaster	Yeah
22:09	gfrlog	okay. then I think the answer is no
22:09	gfrlog	but it might be yes
22:09	TheMoonMaster	Alright, I'll do some research, just curious if anyone had a fast answer.
22:10	brehaut	TheMoonMaster: typically actors define their operations internally (based on some sort of data message) whereas agents hold data and have the operations defined externally (as some sort of behavioural message)
22:10	TheMoonMaster	brehaut: Thanks for the clarification
22:11	brehaut	TheMoonMaster: clojure's agents also use a thread pool for executing on by default where as (at least conceptually in erlang) the agents have their own thread or process (typically lightweight)
22:13	TheMoonMaster	Makes sense, might be a jvm limitation
22:13	brehaut	its a design decision; agents and actors fullfil quite different design roles
22:15	TheMoonMaster	I suppose that is due to the functional nature of clojure
22:15	brehaut	not really
22:15	TheMoonMaster	Oh, I'm super new to functional programming beyond map reduce and filter
22:15	amalloy	TheMoonMaster: you are making a lot of statements of the form "i assume X" but have stated you don't know a lot about the domain. probably best to keep those crazy ideas to yourself for a while
22:15	amalloy	or at least ask about them rather than state them
22:16	TheMoonMaster	amalloy: Sorry about that, I'll keep that in mind
22:46	KineticShampoo	Do you guys use the counterclockwise plugin for eclipse?
22:46	tomoj	TheMoonMaster: I was a rubyist at your age ;)
22:46	tomoj	took me some years after to find clojure though, you've got a head start on me
22:47	TheMoonMaster	tomoj: Oh yeah? I find a lot of similarities in the philosophies between ruby and clojure. I am really loving it so far.
22:47	amalloy	KineticShampoo: some do
22:47	amalloy	most use emacs
22:47	TheMoonMaster	KineticShampoo: I use vim, it's nice with vimclojure
22:48	TheMoonMaster	tomoj: Do you use Ruby anymore? Or have you switched to using mostly clojure or some other language?
22:49	tomoj	if I have a choice I use clojure, ruby only for chef, python and php because people pay me
22:50	TheMoonMaster	Haha, I use PHP because people pay me.
22:50	tomoj	sucks eh?
22:50	TheMoonMaster	Yeah, I am used to it though, it was my first language.
22:51	tomoj	mine too I suppose, but that only reinforces my disgust. plus I had a good 4 years or so without ever having to look at it
22:52	TheMoonMaster	After I understood programming concepts and whatnot I kinda ditched PHP to learn other languages, then a about 3/4 years later I had to reunite with PHP.
22:55	amalloy	php is my most-recent language. it's not a happy language
22:55	TheMoonMaster	Haha, most certainly not.
22:55	TheMoonMaster	Whenever I can I try to use CodeIgniter to ease the pain
22:56	TheMoonMaster	And other times I am tortured by the horrible creation called wordpress plugins
22:56	TheMoonMaster	Writing those is the most annoying thing I have ever done programming wise.
23:01	carllerche	amalloy: eh, why did you learn PHP?
23:02	amalloy	carllerche: job
23:02	carllerche	amalloy: are you in SF?
23:02	amalloy	for now
23:02	carllerche	you should let me buy you a beer sometime for all the help :)
23:22	tomoj	TheMoonMaster: have you written any drupal modules?
23:22	TheMoonMaster	tomoj: Have not, never been a fan of drupal
23:24	tomoj	try never to :)
23:25	TheMoonMaster	tomoj: I think the rule of thumb is try to avoid PHP altogether. lol
23:36	zrilak	I've just been reminded of the difference between "evaluate" and "yield" by this block of code: (if-let [foo (...)] (handle normally) (throw (RuntimeException. (...)) What is the Clojure way to fire an exception in this case?
23:37	zrilak	Do I just split it into (let [...] (if ...)) ?
23:38	amalloy	zrilak: huh? that code looks fine; perhaps you can clarify what you want?
23:38	zrilak	amalloy: if-let does not evaluate the "else" form; I want the exception to be thrown at the time when "if-let" is evaluated, not lazily
23:39	zrilak	or am I horribly misunderstanding something?
23:39	amalloy	haha that apparently confused me so much i /parted
23:40	zrilak	I assumed you hit C-k in the wrong frame
23:40	amalloy	&(if-let [x nil] (prn x) (throw (Exception. "OMG x is false")))
23:40	sexpbot	java.lang.Exception: OMG x is false
23:40	amalloy	zrilak: it already does what you want, is what i am getting at
23:40	zrilak	hrm, gotcha
23:40	zrilak	then it's obviously the "me not digging things right" case :)
23:40	amalloy	or, at any rate, what you are saying you want. it's never safe to assuming those are the same thing :)
23:40	zrilak	thanks
23:40	zrilak	true, true
23:41	zrilak	but again, your patience is limitless. Thanks :)
23:45	TheMoonMaster	Anyone see/use clojure atlas?
23:46	zrilak	I tried it, it's nifty, if a bit buggy
23:46	TheMoonMaster	Yeah, it does seem a bit buggy
23:47	TheMoonMaster	I don't think that was the best way to implement an API browser.
23:47	TheMoonMaster	But it was awesome
23:47	zrilak	Probably not, but it's good that people are experimenting with paradigms
23:47	TheMoonMaster	Yeah, it was an interesting concept
23:52	zrilak	I haven't had so much fun learning a new language since Oberon
23:53	TheMoonMaster	Haha, it feels almost like another ruby to me.
23:53	TheMoonMaster	Which is a good thing
23:54	zrilak	it's driving me crazy, though, I know there are macros and functions that can cut down my code and increase readability, but I just can't bring myself to stop typing and start reading, until I hit a hitch.
23:55	zrilak	I like to evaluate docs lazily
23:56	TheMoonMaster	lol, I'm just trying to take it slow and understand clojure.
23:56	tomoj	cemerick made it?
23:56	tomoj	atlas, I mean
23:56	tomoj	or coincidentally someone else named chas?
23:57	amalloy	tomoj: cemerick
23:57	tomoj	now I feel bad for clicking "I don't want to buy"
23:58	zrilak	buy the book instead :)
23:58	tomoj	which one?
23:58	zrilak	http://www.amazon.com/Clojure-Programming-Chas-Emerick/dp/1449394701
23:59	TheMoonMaster	I am definitely getting that when it's released.
23:59	zrilak	though I've ordered "The Joy of Closure", seems denser