#clojure – 2015-07-27

2015-07-27

00:39	justin_smith	(inc TimMc)
00:39	lazybot	⇒ 101
01:15	rhg135	I wish you were joking
04:44	tgoossens	I have a function (defn blah [q] (.query conn q) (.close conn)) But i need the output of the query. Just us a let?
04:45	tgoossens	(the query output must be the return value, but close conn must come after obviously)
04:56	H4ns	tgoossens: (defn blah [q] (with-open [conn (open-conn)] (.query conn q))) may be an option
04:56	H4ns	tgoossens: but if query can't ever fail, use a simple let.
04:57	tgoossens	H4ns, thanks!
07:46	noncom	is destructuring considered a super low cost operation? I am reading this now http://blog.redlinernotes.com/posts/Lessons-from-cl-6502.html and that spot about destructuring caught my attention
07:46	noncom	sure, the post is about CL, but that made me to think about Clojure destructuring too
07:47	noncom	i suppose the implementations can be comparable..
07:55	wasamasa	nope
07:55	wasamasa	do your own benchmarks and write a blog post
08:29	expez	(let [rdr (LineNumberingPushbackReader. (FileReader. path))] ...) I'm leaking file descriptors here, right?
08:30	schmir	expez: yes
08:30	schmir	expez: use the with-open macro
08:31	expez	mhmm
08:35	jeaye	I'd love some examples of non-trivial open source applications written in clojure so I can see how its idioms scale beyond the 20 line snippets that're so common in articles and tutorials.
08:36	jeaye	Ideally, the projects would hit a nice sweet spot between trivial and too much of a time investment to understand fully. Suggestions?
08:44	hellofunk	jeaye: well the Ring stuff is open source and fairly moderate in size, and is responsible for huge amounts of web sites and web apps in the world
09:20	Leonidas	hi
09:20	Leonidas	I have a macro like this:
09:20	Leonidas	(defmacro nest [sym] `(defmacro ~sym [& more#] (~sym more#)))
09:21	Leonidas	unfortunately, I'd like to actually unquote-splicing more# but it doesn't work, since it is not in a quasi quote
09:21	Leonidas	what can I do?
09:23	Leonidas	(apply does not work, since sym is most likely a macro)
09:30	expez	Leonidas: writing macros to write macros is super uncommon. In the event that you aren't actually an expert in a situation requiring this problem to be solved, you might consider that you've taken a wrong path somewhere further up in the decision tree :)
09:31	tsdh	Leonidas: That can't work. Basically, you want to know the actual arguments to your macro in its very own definition.
09:31	tsdh	expez: Macros writing macros is where the fun starts! ;-)
09:33	tsdh	expez: "Let over Lambda" is a really entertaining book doing all these sorts of multi-stage programming.
09:34	expez	tsdh: That's next on my reading list. Going through On Lisp now :)
09:34	tsdh	expez: Have fun! :-)
09:34	Leonidas	expez: it gets better. I'm writing a macro to write a macro to replace existing macros :-/
09:35	tsdh	Leonidas: Awesome!
09:35	Leonidas	I have mastering clojure macros open too, but didn't get that much time to read it
09:35	Leonidas	LOL is on my reading list as well, though.
09:37	tsdh	Leonidas: Would it work to generate a macro with gets a collection `more` rather than having a varargs `more` parameter. If you need to, you can wrap it later to get to signature you want to have.
09:42	Leonidas	tsdh: the problem is that i have to call this ~sym macro I got passed with varargs
09:45	tsdh	Leonidas: Well, I think I simply don't get the context.
09:47	Leonidas	tsdh: I want to replace the macros of clojure.tools.logging with timbre macros.
09:47	Leonidas	(redef info) should re-def clojure.tools.logging.info with taoensso.timbre.info
09:48	Leonidas	If I replace them by hand-written macros if works just fine, but that's a lot of boilerplate
09:49	Leonidas	I have macros like (defmacro errorf [& more] `(taoensso.timbre/errorf ~@more))
09:50	Leonidas	and would like to replace the errorf part with the argument of the redef macro
09:56	tsdh	Leonidas: Hm, I think you can just build the expansion by hand in the generated macro instead of using quasi-quote.
09:56	tsdh	(defmacro nest [sym]
09:56	tsdh	(let [args (gensym "more")]
09:56	tsdh	`(defmacro ~sym [& ~args]
09:56	tsdh	(list* '~sym ~args))))
09:57	tsdh	Leonidas: Of course, the expansion is an infinite recursion here but that has been in your initial example, too.
09:57	Leonidas	tsdh: yes, I'm rewriting the symbol in my actual code, I just left it out to reduce the noise.
09:57	Leonidas	will try
10:06	Leonidas	tsdh: this fails, it says it can't take the value of the macro
10:07	Leonidas	oh, wait
10:07	Leonidas	I missed the quote
10:09	Leonidas	tsdh: whee, works. thank you a lot! I will have to study this code more in depth
10:09	tsdh	Leonidas: You're welcome!
10:14	xificurC	when I fire up lein repl and in-ns into my namespace and try to evaluate (+ 3 4) I get java.lang.RuntimeException: Unable to resolve symbol + in this context
10:15	tsdh	xificurC: That namespace hasn't been created properly before, i.e., with (ns your.ns ...).
10:16	tsdh	xificurC: Just (in-ns 'foo) creates the namespace without any bindings, i.e., you don't have all the clojure.core functions available and neither the bindings for java.lang classes.
10:17	tsdh	xificurC: So compile your namespace before changing to it, or require it from the repl.
10:17	xificurC	tsdh: I have this under src/xml_palettes/core.clj http://sprunge.us/RYjY
10:18	tsdh	xificurC: Yeah, then (require 'xml-palettes.core) before you (in-ns 'xml-palettes.core).
10:18	xificurC	tsdh: I see, thanks!
10:18	tsdh	xificurC: Or compile it in your environment, e.g., with C-c C-k in CIDER.
10:18	xificurC	using inf-clojure
10:19	tsdh	xificurC: That probably also has a binding for that but I don't know it.
10:20	xificurC	there's only C-c C-l for load file, not sure if that's the same
10:21	xificurC	yeah, that seems to work, thanks tsdh
10:44	dnolen	Bronsa: putting the finishing touches on bootstrapped ClojureScript. Will probably cut a pre-release if you could cut a tools.reader release that depends on it, that would be great, then people can do some testing before we cut a "final" ClojureScript one.
10:48	Bronsa	dnolen: sure, I'll cut a 0.10.0-alpha2 release -- don't think I can or even need to depend on a "future" version of cljs
10:49	Bronsa	it'll just work when pulled in by the new cljs and not work if pulled in by older versions
11:11	dnolen	Bronsa: ok, thanks!
11:33	noncom\|2	,(concat '(1 2 3) {:a 1})
11:33	clojurebot	(1 2 3 [:a 1])
11:33	noncom\|2	ummmm... how can that be?
11:34	justin_smith	,(seq {:a 1}) ; because this
11:34	clojurebot	([:a 1])
11:34	justin_smith	each entry is a two element vector
11:34	noncom\|2	ah!
11:34	noncom\|2	whoops, i was thinking i started sliding..
11:34	noncom\|2	mixed up concat with conj..
11:34	noncom\|2	it should be conj..
11:35	justin_smith	,(conj '(1 2 3) {:a 1})
11:35	clojurebot	({:a 1} 1 2 3)
11:35	noncom\|2	yeah, the order is backwards coz it's a list
11:35	justin_smith	,(into '(1 2 3) {:a 1})
11:35	clojurebot	([:a 1] 1 2 3)
11:35	noncom\|2	hmmmm
11:38	hellofunk	justin_smith: didn't you say you are using http-kit to create websockets on a clojure server? how is that working out for you, anything i should be aware of when giving it a go after working on jetty?
11:41	justin_smith	hellofunk: it's been working fine for me
11:41	justin_smith	hellofunk: using sente to do it
11:43	hellofunk	justin_smith: is sente basically an abstraction over the http-kit websocket support?
11:43	justin_smith	hellofunk: it is protocol based, it abstracts http-kit and aleph iirc
11:43	justin_smith	it definitely has more than one supported backend
11:44	justin_smith	hellofunk: it lets you use websockets pretty much as if it were core.async
11:44	hellofunk	justin_smith: http-kit's docs suggest the websocket support is already quite easy without any other libraries; what is the advantage of adding sente to the mix?
11:45	justin_smith	hellofunk: you can directly provide clojure datatypes, it covers the serialization / deserialization, and hooks it up to core.async channels
11:45	justin_smith	also it has routing facilities
11:46	hellofunk	word
11:46	justin_smith	if you plan on making your own serialization / deserialization, doing your own routing and async hookup, it won't do much fore you I guess
11:47	justin_smith	on my next project I plan on trying the plain websocket route - I started with sente on this one and it just worked
11:48	hellofunk	"it just worked"... ? you mean Apple invented it?
11:49	justin_smith	it behaved as expected, at first
11:49	justin_smith	since then I have had to intrusively extend the serializer, and put my own routing layer on top...
11:49	justin_smith	stuff that makes me think I could start from scratch next time :)
11:50	justin_smith	hellofunk: it suffices if all you need is one button
12:09	arrdem	justin_smith: so um fair warning gonna harass you about websockets eventually (tm)
12:10	justin_smith	arrdem: cool
12:11	justin_smith	arrdem: one thing that worked out super awesome for our team was defining a single cljc file that defined routing for websocket messages going in both directions, it made hooking up new functionality much less of a tangle
12:12	arrdem	justin_smith: nice!
12:12	justin_smith	otherwise you get the whole "wait, which end do I define first, did I hook up all the fiddly details, oh man I have to edit five different files to make this work" freakout
12:12	arrdem	DRY
12:13	justin_smith	right - if you can define the routes that handle the request and the reply in one place, and then those refer to the functions called - it becomes a nice tree of code to implement with the router at the top, and you just walk down the tree until done
12:13	justin_smith	because otherwise with two way messaging you can get lost in a tangle of calls and responses way to easily, and lose track of details fast
12:14	justin_smith	(which is starting to happen to me now that we add kafka messaging alongside the websockets... ugh).
12:14	arrdem	sure. cool! a year or two ago I remember trying to play with websockets because some of the *coin exchanges exposed websocket data streams for transactions that I couldn't trivially consume
12:14	justin_smith	arrdem: turns out, managing two party communication is 1/3 as complex as managing 3 party communication
12:14	arrdem	now you have a distributed system. merry christmass.
12:15	justin_smith	arrdem: indeed, don't I know it
12:15	justin_smith	arrdem: I would have settled for a puppy, much less work
12:15	justin_smith	and my distributed system doesn't like belly rubs
12:15	arrdem	haha
12:16	arrdem	's ok you have a distributed system that doesn't like belly rubs, my emitter has been giving me the stinkeye of late too :P
12:16	justin_smith	in all seriousness, we did intend to make a distributed system, but even when you go into it with the attitude "distributed systems are hard, this is going to be a lot of work" - - it turns out distributed systems are still harder than that
12:17	justin_smith	I've been perusing the Lynch Distributed Algorithms book for guidance / orientation, which helps
12:18	justin_smith	even if I am not implementing those algorithms from scratch (kafka and onyx do those things for me), it's good to see why things are arranged the way they are
12:18	arrdem	have you written up or even just found a good Clojure network simulator?
12:18	justin_smith	hmm
12:18	justin_smith	no, I have not
12:18	arrdem	I've got some fun ideas for vector clock based systems but I haven't actually built out anything to prototype them
12:19	arrdem	lol @ activation energy
12:22	justin_smith	arrdem: do jepsen or rymann do any of this, or do they do their simulation / interferance on an OS level?
12:22	justin_smith	sorry, riemann
12:24	arrdem	justin_smith: I can't quite tell but it looks like jepsen is probably a framework for doing exactly that sort of simulation testing
12:25	arrdem	justin_smith: presumably it is and once aphyr gets the talk "done" it'll stablilize :P
12:25	justin_smith	arrdem: I think it uses linux kernel / system calls to do the "simulation" - so it is OS level simulaiton
12:25	justin_smith	which may suffice ?
12:26	justin_smith	arrdem: https://github.com/aphyr/jepsen/blob/master/doc/lxc.md
12:27	arrdem	justin_smith: right so this is a framework for spinning up and then partitioning networks of vms
12:27	justin_smith	exactly
12:28	arrdem	hum. I think that for what I'm after local testing with something akin to core.async to simulate a network buss would be sufficient.
12:28	arrdem	anyway. pleny of other yaks
12:57	clojer_	How do I get a Reagent app uberjar to serve gzipped js files?
13:12	Seylerius	Hrm. How do I turn an clj-time interval into a decimal fraction of days?
13:13	Seylerius	596.23 days, for example.
13:24	joegallo	Seylerius: (in-days the-interval)?
13:28	amalloy	justin_smith: recalling last week's discussion about the oddities of clojure.core/destructure, what do you suppose are the values of a/b/c/d in (let [[a :as b c :as d] (range 5)]) (and, are any of them unbound?)
13:29	justin_smith	amalloy: oh, wow... umm a would be 0 I think, b would be the range... c and d nil?
13:29	justin_smith	wild guess there
13:29	amalloy	c and d are unbound, it turns out
13:29	amalloy	but you don't get an error from the let-binding if you don't try to use c or d
13:29	amalloy	you can just write any old junk after an :as
13:30	amalloy	,(let [[x y :as z 1 2 3 whatever] (range 5)] [x y z])
13:30	clojurebot	[0 1 (0 1 2 3 4)]
13:30	justin_smith	amalloy: I'm surprised how close I was to right there- but also surprised that those values are unbound rather than nil
13:31	justin_smith	(given the other behaviors I have seen)
13:31	amalloy	justin_smith: destructure just stops processing the binding list once it gets to :as
13:31	amalloy	so it doesn't create bindings for those
13:31	Bronsa	unbound is slightly better than nil in this case
13:31	justin_smith	amalloy: hidden comment feature!
13:31	Bronsa	at least you get a runtime error rather than nothing
13:31	amalloy	yeah
13:31	justin_smith	Bronsa: yeah, I would rather have seen unbound errors in the other misuses of destructure
13:32	kavkaz	Does the condition map in a function, specifically for the :pre key, have an effect? Or is it purely for documentation?
13:32	justin_smith	I guess silently ignoring erroneous input can be one drawback in the general "data structures before functions, functions before macros" thing - where unused parts of the data structure can look like functionality you were intending to invoke but never get evaluated
13:33	Bronsa	,((fn [a] {:pre [(string? a)]} a) 1) ;; kavkaz
13:33	clojurebot	#error {\n :cause "Assert failed: (string? a)"\n :via\n [{:type java.lang.AssertionError\n :message "Assert failed: (string? a)"\n :at [sandbox$eval50$fn__51 invoke "NO_SOURCE_FILE" 0]}]\n :trace\n [[sandbox$eval50$fn__51 invoke "NO_SOURCE_FILE" 0]\n [sandbox$eval50 invoke "NO_SOURCE_FILE" 0]\n [clojure.lang.Compiler eval "Compiler.java" 6792]\n [clojure.lang.Compiler eval "Compiler.java" 6...
13:33	justin_smith	kavkaz: it has an effect if assertions are on, whether assertions are on is a vm level thing outside clojure's control
13:33	Bronsa	justin_smith: there's actually clojure.ore/assert
13:33	justin_smith	Bronsa: oh, wow
13:34	justin_smith	Bronsa: I thought it just used the vm config. But anyway I think the same takeaway is there - it's a thing that a user can turn off, so don't rely on assertions enforcing correctness, but do use them to detect bad code.
13:35	Seylerius	joegallo: I'll try that, thanks.
13:35	kavkaz	Bronsa, justin_smith: thanks! saw somebody use it in book. Can i put anything inside that map? Before I knew it was a condition map, i played around with a function and added :hi "hi" to the map. Can I use this like let?
13:35	kavkaz	I know it wouldn't be idiomatic and it will be confusing, but in theory I could do that right?
13:36	justin_smith	kavkaz: it pays attention to the :pre and :post keys - you can put anything in there, but why?
13:36	amalloy	that wouldn't be anything like let. it wouldn't create any bindings
13:36	justin_smith	kavkaz: it isn't like let because it doesn't create bindings you can usefuly refer back to does it?
13:36	Bronsa	yeah sure -- there's actually a vm thing for the `assert` statement in java but we don't use that
13:37	justin_smith	Bronsa: I had figured that since it was raising an AssertionError, turning off assertions would turn it off
13:37	kavkaz	Oh i see, i put a string in there "bound" to a key, it compiled but I guess I never tried referring to that string
13:53	amalloy	i just tride building clojure/clojure for the first time in ages, and `mvn test` prints a bunch of errors about edn round-tripping failures. is that command supposed to work, or is that the wrong way to run clojure's tests?
13:57	arrdem	I believe that is indeed the official test command
13:57	Bronsa	amalloy: it's supposed to work
13:58	Bronsa	amalloy: maybe you had some stale files in target/ or an unclean git history?
13:59	amalloy	the git history is clean, i'm exactly on latest master. stale files in target sounds like it is probably right
14:00	amalloy	Bronsa: thanks, it all works fine after deleting target. i wonder how old that stuff was
14:02	joefromct	can anyone recommend a current book, article, or blog in regards to getting started with clojure over hadoop processing? seems everything is a few years old at this point... i've looked at clojure-hadoop, netflix pigpen, and cascalog.
14:02	joefromct	any tips appreciated.
14:02	arrdem	amalloy: probably pre-1.7 printing changes
14:19	justin_smith	joefromct: I know yieldbot has a few nice things. And big picture if you need distributed computation but might not actually specifically need hadoop, check out onyx
14:25	joefromct	justin_smith: that looks interesting, thanks i'll check it out.
14:26	justin_smith	joefromct: I've been experimenting with onyx and like it so far. The project lead is pretty responsive if you need help getting oriented.
14:41	pepijndevos	How the hell do I make a Hiccup select box? There is this select-options thing, but I can't get it to work, and I can;t find any examples.
14:42	arrdem	Has anyone messed with a "server" command mode for leiningen where you get a repl for issuing lein commands rather than a Clojure repl?
14:43	justin_smith	arrdem: lein 1.x had this and 2.x does not for reasons which are reasonable but forgotten by me
14:43	justin_smith	arrdem: of course you can do that easily with boot
14:43	arrdem	justin_smith: sure. ok. maybe time for some mail list archeology later then.
14:44	justin_smith	arrdem: hyPiRion might remember why long running lein executing various tasks stopped being a thing
14:44	amalloy	arrdem: it was called lein interactive, if this helps your searching
14:46	arrdem	https://groups.google.com/forum/#!msg/leiningen/whV-VUdKSWM/O9H7cUQbGF8J
14:49	reuigerg	Hi! I'm making my first web service in Clojure. I made non-web projects in the language, and would like to use it for web stuff too. My hope is not having to go back to Django and Rails for these things. I'm struggling with Authentication. There are 2 libraries in CLJ for doing this, Friend and Buddy. Does anyone have any experience with these, and can tell which one will get you off the ground with the least amount of wor
14:49	reuigerg	elegant solution, but want to have an "account" feature (log in, register, keep a token) before bedtime today. So: What is the leanest way to do authentication in Ring/Compojure webapps?
14:56	justin_smith	reuigerg: the first part of your question was too long and it got cut off by IRC
14:57	reuigerg	Sorry - I'll re-ask more briefly
15:00	reuigerg	I'm making my first Clojure web (& postgres) project (having done non-web stuff). It requires user accounts (login with email+password, save a token to cookie, validate that token on every request). From what I can see, most people either use the lib Friend or Buddy. I'd like to implement this feature as soon as possible, so my question is: what is, in your experience, the leanest and quickest way to implement this in a ri
15:00	reuigerg	webapp? What are some great texts to read, in order to understand how to do this? Like a screencast or tutorial.
15:03	justin_smith	reuigerg: first half was cut off again
15:03	reuigerg	Shortest version: What is the quickest and leanest way to do user account & authentication in Ring/Compojure webapps? Are there any good guides for this?
15:03	reuigerg	Sorry :(
15:03	justin_smith	reuigerg: it's OK, wanted to make sure we weren't missing essential stuff...
15:04	justin_smith	I looked into friend and just ended up whipping something up with ring-session and bcrypt, I've talked to a few other people with similar stories
15:05	reuigerg	I see. I'm wrestling with Friend as well at the moment, but don't know how to make sense of it all yet. Worried about doing it all vanilla, because it seems easy to screw up (and then screw all users over)
15:06	justin_smith	reuigerg: a) don't store a password, store the bcrypt hash b) use the bcrypt hash-verification function on login
15:07	justin_smith	and do this over ssl, of course
15:07	justin_smith	there's not a lot of moving parts there
15:08	justin_smith	if you need the extra workflow stuff from friend, use it of course. But for simpler setups it seems more trouble than it's worth.
15:09	reuigerg	justin_smith: Ok, thank you. Maybe that is the easiest way. Btw, I've seen you answer questions a lot in #clojure. Thanks for that! Appreciate it
15:10	expez	reuigerg: you might want to check out Buddy
15:10	justin_smith	I try, hopefully it's helpful
15:10	expez	reuigerg: https://github.com/funcool/buddy it's easier to pick and choose from buddy than it is from friend
15:11	reuigerg	justin_smith: how do you then check authentication on each request? I guess you always want to assure that the user is logged in. Do you save a session somewhere, or generate that (like in JWT)?
15:11	ed-g	reuigerg, I found a useful Friend tutorial @ https://github.com/ddellacosta/friend-interactive-form-tutorial
15:12	ed-g	reuigerg, I'm in the same boat you are.
15:12	justin_smith	reuigerg: jwt if we load balance (WARNING: default for jwt is to accept the encoding type as provided by client, one of the encoding types is "none" which allows them to provide auth in plaintext and is a huge security hole. Be sure you are whitelisting encoding methods server side)
15:12	reuigerg	expez: I see. Have been fighting with both Friend a couple of days, but havent figured it out
15:12	reuigerg	ed-g: cool! Thank you! Will read :)
15:12	justin_smith	reuigerg: if not using load-balancing, it's easy to have a server side in-memory session and require users to log back in after restarts
15:14	reuigerg	justin_smith: valid point
15:17	reuigerg	To you all who answered: thank you for helping a guy confured in an unfamiliar but exciting labyrinth of parens
15:17	cmarques	What's the preferred way of doing function stubbing when testing with clojure.test?
15:19	justin_smith	cmarques: best option, if you can pull it off, is to parameterize your code so you don't actually need to mock a specific var
15:19	justin_smith	otherwise there is with-redefs
15:19	amalloy	arrdem: you mentioned wanting to see my reimplementation of destructure. not that i expect it would ever get in, but the patch is at https://www.refheap.com/bdd1b19b6f60d21fc00e48e0e. i'm no really sure about the change to use next/first instead of nth; it'll be faster for seqs, and involve one wasted allocation for vectors
15:20	cmarques	justin_smith my specific case: I have a ring handler that calls a function foo that accesses the database. When testing the handler, I don't want to access the database.
15:20	justin_smith	cmarques: yeah, sounds like a good use case for with-redefs, unless you want a test db
15:21	justin_smith	cmarques: or you could have a middleware that supplies the db access function, which could be replaced with a non-db replacement while testing
15:21	justin_smith	whatever is cleaner in your use case
15:22	cmarques	justin_smith I am looking at with-redefs, seems to do what I need. Thanks for your help!
15:24	justin_smith	cmarques: as with any with-foo, be super careful about scope+ laziness leading to unexpected results
15:24	justin_smith	basically, either do your work inside the body, or force anything lazy before returning it
15:25	cmarques	I see, I'll keep that in mind!
15:34	crazydiamond	Hi. If I have (defn f [a b] (+ a b)), can I get '(+ a b), i.e. the body?
15:34	justin_smith	no
15:35	justin_smith	well, you can from #'f
15:35	crazydiamond	so, I should have code in a first place
15:35	justin_smith	but not from the value of #'f
15:35	amalloy	justin_smith: not even from #'f really
15:35	hiredman	depends what you mean by having (defn f [a b] (+ a b))
15:35	justin_smith	,(defn f [a b] (+ a b))
15:35	hiredman	if you run that through eval (the compiler) then you don't have it
15:35	clojurebot	#'sandbox/f
15:35	hiredman	you have compiled byte code
15:35	justin_smith	,(:source #'f)
15:35	clojurebot	nil
15:35	justin_smith	ahh
15:36	crazydiamond	aha
15:36	hiredman	if you actually have (defn f [a b] (+ a b)) then
15:36	amalloy	justin_smith: source reads the .clj file
15:36	justin_smith	right, I forgot
15:36	crazydiamond	I tried to get it with clojure.repl/source and got "Source not found"
15:36	hiredman	,(-> (defn f [a b] (+ a b)) (nth 3))
15:36	clojurebot	#error {\n :cause "nth not supported on this type: Var"\n :via\n [{:type java.lang.UnsupportedOperationException\n :message "nth not supported on this type: Var"\n :at [clojure.lang.RT nthFrom "RT.java" 881]}]\n :trace\n [[clojure.lang.RT nthFrom "RT.java" 881]\n [clojure.lang.RT nth "RT.java" 847]\n [sandbox$eval72 invoke "NO_SOURCE_FILE" 0]\n [clojure.lang.Compiler eval "Compiler.java" 68...
15:36	hiredman	,(-> '(defn f [a b] (+ a b)) (nth 3))
15:36	clojurebot	(+ a b)
15:37	crazydiamond	ok, got it. thanks!
15:37	TEttinger	,(-> '(defn f [a b] (+ a b)) (nth 3) eval)
15:37	clojurebot	#error {\n :cause "Unable to resolve symbol: a in this context"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Unable to resolve symbol: a in this context, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyze "Compiler.java" 6611]}\n {:type java.lang.RuntimeException\n :message "Unable to resolve symbol: a in this context"\n ...
15:37	TEttinger	,(-> '(defn f [a b] (+ a b)) eval)
15:37	clojurebot	#'sandbox/f
15:37	TEttinger	,(f 3 4)
15:37	clojurebot	7
15:37	TEttinger	nice clojurebot!
15:37	TEttinger	(inc hiredman)
15:37	lazybot	⇒ 81
15:37	hiredman	clojurebot: source?
15:37	clojurebot	source is http://github.com/hiredman/clojurebot/tree/master
15:38	hiredman	meh
15:38	hiredman	source is misleading
15:47	devnewb	hi all can anyone point me to an example of core.async ‘async/reduce’ in the wild, I can’t seem to aggregate my channel results into it.. I only get the last item
15:48	cmarques	justin_smith: Just solved the problem with with-redefs, works beautifully! Thank you!
15:49	devnewb	I’ve tried something like : (println "merged : " (async/<!! (async/reduce merge {} some-chan)))
15:50	justin_smith	cmarques: (async/reduce conj [] some-chan) is less interesting, but has fewer gotchas
15:50	justin_smith	cmarques: cool, glad to hear it worked out
15:55	devnewb	justin_smith, thanks, I already had that and it worked.. I was just trying to puzzle through the merge gotchas… thanks for the pointer though
15:57	justin_smith	devnewb: if conj worked and merge did not, I would look at the hash maps you are merging - maybe you want merge-with and not merge
15:57	justin_smith	,(merge {:a 0} {:a 1} {:a 2})
15:57	clojurebot	{:a 2}
15:57	justin_smith	,(merge-with + {:a 0} {:a 1} {:a 2})
15:57	clojurebot	{:a 3}
15:58	devnewb	justin_smith: ah, thanks
15:58	devnewb	I was misunderstanding merge
15:58	devnewb	should have read the docs more
16:09	justin_smith	(inc docs)
16:09	lazybot	⇒ 2
16:12	vas	Hi Guys, I finally have my site live, the login system is just an "email you a link and you click it" ... it works (!) but when I first run the app it takes an unusually long amount of time to send the first email... any ideas as to how I can get more "what's going on under the hood" feels/insight?
16:17	vas	maybe it's a mail issue o.O
16:20	oddcully	vas: if you send your email synchronously, then there could be an overhead for establiching everything to make the mail go out
16:20	oddcully	vas: things like authing and reverse lookups on hosts etc
16:21	vas	oddcully: you know it sounds like that might be it. i'm using postal to send mail. i wonder if there's a way to do it asynchronously and just kinda "throw it on the queue"
16:24	justin_smith	vas: you could put the send in a future (and be sure to come back and check the future for errors later)
16:25	dagda1_	when working with a binary tree clojure devs use zippers?
16:25	dagda1_	would clojure devs
16:26	justin_smith	dagda1_: that is one approach. If you are just navigating one a recursive function might suffice.
16:26	amalloy	depends what you are doing with the tree. usually not
16:26	dagda1_	amalloy would you just use a map?
16:26	amalloy	conveniently the same answer applies: depends what you are doing with the tree. usually not
16:27	vas	oddcully: I added a line to my apache config "ProxyBadHeader Ignore" and it works... =\|
16:28	vas	justin_smith: that's a cool idea. The future part of that makes sense to me, but how would one "come back to check errors" ?
16:29	dagda1_	well that cleared things up......glad I asked
16:29	justin_smith	vas: put the future somewhere where you can access it later (perhaps an atom). You can test if it has returned with realized?
16:29	justin_smith	vas: if you access the value, it will throw the exception it caught, if any
16:30	justin_smith	so you can put your exception handling code in a function (maybe another future...) that comes back later and checks that it was successful
16:31	justin_smith	of course this assumes that it is reasonable to fire-and-forget your email sending while handling a request, and come back and deal with errors (if any) later
16:32	oddcully	vas: also depends, if you really need to tell the user, that you have sent the email. you can as well just tell the user, that you have done so and just records failures on your server for forensics
16:32	amalloy	dagda1_: the point is, what you use to work with a data structure depends on what you want to do. you could as well ask "how would you work with an integer? would you just use division?" well, probably not, but i can't be sure without knowing your goal
16:34	oddcully	vas: i also don't see how the apache config there relates; i only know, that javamail takes a short time to establish stuff. it's in general a good idea to offload sending mails to a queue/worker/... since there can be errors all over the place
16:37	dagda1_	amalloy I am just tyring to solve this problem https://www.hackerrank.com/challenges/swap-nodes and to me a zipper seemed a good approach which made me wonder what somebody with more experience in clojure would use
16:41	amalloy	you might build the tree with a zipper. their input format is pretty hostile. the swapping seems like it would be easier to do with just some recursion of your own? i dunno, maybe you could use a zipper for that easily enough too
16:42	justin_smith	dagda1_: hell, I think that flip could be done with get-in / update-in
16:42	justin_smith	granted, that's after a skim, maybe that's too simple
16:42	amalloy	justin_smith: for all nodes at depth N? seems a bit tricky
16:43	justin_smith	ahh, yeah, so maybe recursion + update-in, right
16:53	crazydiamond	Hwdy get all subsequences of a vector? Like [1 2 3] -> [[1 2 3] [1 2] [2 3] [1] [2] [3]]?
16:57	amalloy	you forgot []
17:02	crazydiamond	amalloy, where? :)
17:02	crazydiamond	ah, yep
17:02	crazydiamond	0-length one
17:06	amalloy	anyway crazydiamond, of course there is nothing like this built in. you can build your own pretty easily with the use of clojure.core/partition
17:07	crazydiamond	amalloy, thanks. I was thinking about two nested loops
17:07	amalloy	in a functional language, you usually want to be thinking about recursion instead
17:08	amalloy	(here, as in many cases, there is a better solution that involves combining some other built-ins, but doing it recursively first is a good exercise)
17:10	crazydiamond	in the meantime, I wonder why Rich Hickey made that (loop ...) explicit, but not e.g. transformation of tail recursion into loop/recur style
17:10	crazydiamond	(though, I bet one might construct complex enough macro for it)
17:14	scriptor	crazydiamond: as I understand it, they wanted recur to be explicit so that it could be used as desired
17:14	scriptor	otherwise, since there's no actual TCO
17:15	scriptor	it'd be somewhat unclear when a function gets optimized or not
17:15	crazydiamond	aha, make sense
17:17	akkad	crazydiamond: jvm limitations? stack overflow
17:29	crazydiamond	amalloy, do you think this is good enough solution for my problem? or overcomplicated? http://dpaste.com/2DYXPPW
17:31	amalloy	you didn't like the partition suggestion? it is a much simpler way to write your all-subvecs-of...
17:31	amalloy	,(partition 3 1 (range 5))
17:31	clojurebot	((0 1 2) (1 2 3) (2 3 4))
17:33	crazydiamond	ah... yep
17:33	crazydiamond	I was thinking it returns only first one
17:33	crazydiamond	lol
17:34	crazydiamond	thanks for help!
17:37	amalloy	anyway, the simpler solution i alluded to earlier is ##((fn all-subvecs [xs] (cons [] (mapcat #(partition % 1 xs) (range 1 (inc (count xs)))))) (range 4))
17:37	lazybot	⇒ ([] (0) (1) (2) (3) (0 1) (1 2) (2 3) (0 1 2) (1 2 3) (0 1 2 3))
17:43	crazydiamond	I'm so far from real solution. 'Cause what I want to do in the end is to extract common parts from functions (automated refactoring). And now I'm considering turning 1-argument function chains like (a (b (c))) and (a (b (d))) into [[(fn f0001 [x] (a (b x)))] (f0001 (c)) (f0001 (d))]
17:50	joefromct	does anyone use parkour? I'm getting a strange class-not-found exception from the stable github checkout, and it's as simple as adding a lein dep.... no idea if i'm missing something. doesn't seem to be any issues.
17:50	joefromct	(from others)
17:53	hiredman	I haven't used it in a while, what class not found exception?
17:55	hiredman	I think I had to add a few hadoop artifacts as provided dependencies when I used it
17:55	joefromct	hiredman: yeah, i think thats what i did wrong. i bet i added hadoop stuff, but incorrect versions for my cluster or something .
17:56	hiredman	https://github.com/damballa/parkour/blob/master/doc/intro.md
17:56	hiredman	could be
17:56	joefromct	yeah, i copied those dependencies verbatum
17:56	joefromct	*verbatim
17:56	hiredman	ah, and if you are on emr, it needs to be 2.2.0
17:56	hiredman	(or it did last time I was)
18:01	joefromct	hiredman: maybe it has something to do with my lein :user profile... i don't think it's pulling any of them. i just added hadoop as a project dep. and it pulled a bunch of dependencies
18:01	joefromct	weird
18:01	joefromct	*wierd
18:01	hiredman	yeah it shouldn't pull them in
18:02	hiredman	that is what provided means, it means whatever environment the project runs in will provide them
18:02	joefromct	so, if it's in my user profile, and i put ":provided" , i need to add to my classpath manually or something ?
18:02	hiredman	I don't think so
18:02	joefromct	i guess i need to read up on that
18:02	joefromct	i haven't used :provided for anything i've done this far
18:03	amalloy	i don't think you want a provided dependency in your user profile. that sounds weird
18:03	hiredman	the parkour local running should take care of it for testing, and the cluster will provide them for deploying
18:03	joefromct	ok. i'll just have to somehow be sure that my cluster "provides" that stuff at the same version and whatnot i guess.
18:18	Guthur	Hi, I was wondering if anyone has used Javelin with Reagent
18:19	Guthur	I like javelins cell approach for data flow, but find myself having to wrap the value in Ratoms to get the dynamic updates of reagent
18:19	Guthur	has anyone found a nice pattern for this
18:32	michaniskin	Guthur: you can check out https://github.com/HostelRocket/aspis for ideas
18:34	michaniskin	oh nevermind, i thought it was a different thing
18:34	jonathanj	is there something like (update) or (update-in) that operates on vectors?
18:35	hiredman	,(update-in [0 1 2 3] [0] inc)
18:35	clojurebot	[1 1 2 3]
18:35	jonathanj	hrm, and if i have nested vecs? [["a" 0] ...]
18:35	hiredman	,(update-in [0 [0 0] 2 3] [1 0] inc)
18:35	clojurebot	[0 [1 0] 2 3]
18:37	jonathanj	,(map #(update-in % [1] inc) [["a" 0] ["b" 1]])
18:37	clojurebot	(["a" 1] ["b" 2])
18:37	jonathanj	but i was hoping for something more elegant
18:38	hiredman	you asked for something like update-in, and you got update-in exactly
18:39	jonathanj	no need to be defensive, i'm just trying to write better code
18:40	justin_smith	jonathanj: so what thing would be "like update-in but for vectors" and more elegant than using update-in with a vector?
18:40	jonathanj	i meant more elegant than map with an anonymous function
18:40	amalloy	jonathanj: ##(doc for)
18:40	lazybot	⇒ "Macro ([seq-exprs body-expr]); List comprehension. Takes a vector of one or more binding-form/collection-expr pairs, each followed by zero or more modifiers, and yields a lazy sequence of evaluations of expr. Collections are iterated in a nested fashion, rightmost ... https://www.refheap.com/107101
18:41	amalloy	is usually prettier than map with a lambda
18:42	TEttinger	,(mapv (juxt first (comp inc second)) [["a" 0] ["b" 1]])
18:42	clojurebot	[["a" 1] ["b" 2]]
18:42	hiredman	I am saying, you asked for update-in, and you got it, udpate-in works on maps and vectors the same way, if you wanted something more, then you should ask for that
18:42	TEttinger	no anonymous functions, tricky as heck
18:43	hiredman	it sounds like want you want is more like an a tree transform library like xlt or whatever for xml
18:43	TEttinger	anonymous functions can be more elegant that point free style when it's abused like I did
18:43	hiredman	I am sure someone has written such a thing for clojure, but writing your own shouldn't be that hard either
18:44	TEttinger	clojure.zip might be a good starting point?
18:44	jonathanj	i guess i want something like lenses
18:50	TEttinger	jonathanj: there's a series of articles on this blog about lenses in clojure, the first one is mostly about how update-in and assoc-in largely fill the same role. http://blog.podsnap.com/vanhole.html
18:50	jonathanj	TEttinger: yes, thank you, i found those upon searching for lenses in clojure, i'm busy reading through the series right now
19:13	bjarn	does anyone know if there is a way so pass a string directly into a query using java.jdbc’s query function, such that the string becomes a part of the query itself and not a parameter to the query?
19:14	hiredman	use the str function
19:15	hiredman	[(str "select * from " table-name " where foo = ?") 5]
19:17	bjarn	wow, that should have been way more obvious than it was five minutes ago
19:18	bjarn	wait, you mean the standard library will help with that???
19:18	lazybot	bjarn: How could that be wrong?
19:18	bjarn	thanks!
19:50	shayne_	Can you reference a let defined var from within a fn passed as an argument to the righthandside of that let declaration?
19:51	spieden_	shayne_: i'm pretty sure the function will close over it. you can reference symbols defined within the same let in any case
19:52	shayne_	e.g. (let [xyz (foo (fn [] (... xyz)))])
19:52	hiredman	no
19:53	hiredman	the simple way to refer to that is as a recursive let binding
19:54	hiredman	the way to reason about it is ((fn [xyz] ....) (foo (fn [] (... xyz))))
19:55	shayne_	hiredman - new to this, mind elaborating a little?
19:55	hiredman	(which is not to say the forms are equivilant, but it correctly guides the intuition in this case)
19:55	shayne_	thanks chewing on that
19:57	hiredman	some other languages have a thing called let rec, which will let you do stuff like that, clojure has letfn, which allows you to have local functions that are mutually recursive, but it is limited
20:00	shayne_	hireman: a little more color on what I'm trying to do: (let [id (addListener obj (fn [] (...) (...) (removeListener obj id)))])
20:01	shayne_	the api I am working with emits an ID when you call addListener and I'd like to reference that ID within this closure. Something that's fairly trivial in, say, JavaScript.
20:02	shayne_	hiredman* ^^
20:12	futuro	it sounds like what you want to do is bind a new value to id based on a previous value in id, so something like (defn fun [id] (let [id (addListener ...)]))
20:16	shayne_	furturo: close, but I actually do want the most recent reference to remove the listener's callback from its own callback
20:18	futuro	It doesn't?
20:20	shayne_	the value of id is the listener that was just added and inside of the listener's callback I want to remove the listener so the callback (itself) will no longer be called.... in js: var id = SomeObj.addListener(()=> { ...; SomeObj.removeListener(id)})
20:23	futuro	everything I've seen so far seems to imply that precisely what you have described should happen, and then id will be bound to whatever value is returned by addListener, so I have no clue why it wouldn't
20:30	shayne_	futuro: given the let method I described or another suggestion?
20:31	futuro	given the let method you described
20:33	shayne_	futuro: it doesn't appear to (it's nil) as the let expression is evaluated the fn that acts as the callback is not capturing the named var on the left-hand side of the let.
20:36	futuro	you'd need to pass in id before hand. That is, inside the let expression the first id will have no value initially. So (let [foo (some-fn) bar (str foo)]), before some-fn is evaluated, is somewhat like (let [nil (some-fn) bar nil]), since none of the LHS variables have had values assigned to them yet
20:38	futuro	if you want to pass in a value for id to some-fn at a later time you could use an anonymous function, or (partial), but since id hasn't had a value assigned to it yet, referencing it is nonsensical
20:39	shayne_	with: (let [id 0 id (addListener obj (fn [] (...) (removeListener obj id)))]) id: is always 0
20:42	futuro	does addListener return a value?
20:42	shayne_	futuro: yes
20:42	justin_smith	futuro: that wouldn't change how id is assigned - the initial value will always be shadowed
20:42	shayne_	futuro: Here's my workaround: (def id 0) (set! id (addListener obj (fn [] (...) (removeListener obj id))))
20:42	justin_smith	though the addListener call will not be able to use it's own return value in that lambda
20:43	justin_smith	that's terrible - def should not be used that way
20:44	shayne_	justin_smith- just a workaround
20:44	shayne_	and I know it's terrible... bleck
20:44	futuro	justin_smith: id is not shadowed before the binding inside of let, but every reference afterwards it will be
20:44	shayne_	I really felt like this was something I was overlooking, because this pattern is so simple in other languages.
20:45	futuro	,((fn [x] (let [x (inc x)] x)) 1)
20:45	clojurebot	2
20:46	futuro	shayne_: without knowing more about what code you're working with, it sounds like you might be running into trouble with the immutable data structures of clojure, and the various methods of forcing mutability (like swap!)
20:46	shayne_	the problem is the lambda is passed into the expression that returns the value it needs to capture
20:46	shayne_	again consider the JS... var id = obj.addListener(function() { ...; obj.removeListener(id); });
20:47	justin_smith	futuro: shayne_: the answer is to use a promise
20:47	shayne_	there's no immutability
20:47	shayne_	err... mutation
20:47	shayne_	justin_smith: right
20:47	shayne_	justin_smith: doing that now
20:47	justin_smith	(let [id (promise)] (deliver id (fn [] ... (something @id))))
20:47	justin_smith	that's how you do it
20:48	justin_smith	shayne_: you understand the problem with using def right? def only creates globals, it doesn't do local scope
20:49	justin_smith	err, by globals I mean vars at the top level of a namespace, of course
20:50	shayne_	justin_smith: was just playing with the code, but a good reminder
20:51	justin_smith	shayne_: I'm pedantic about that one because it is one of the biggest differences between clojure and scheme, and a common mistake of newcomers from scheme
22:00	arrdem	Bronsa: ping
22:03	Bronsa	arrdem: pong
22:05	namra	does somenone know a vim command to move n lines up or down?
22:06	namra	the motion docs don't provide any info
22:06	justin_smith	namra: <x>t<y> where x and y are numbers
22:07	justin_smith	namra: never mind, that is wrong
22:07	namra	justin_smith: sorry didn't state my question clearly, i just want to move the cursor
22:08	justin_smith	namra: oh, <x>j or <x>k to move x lines down or up
22:08	justin_smith	there is also Control+f and control+b for moving by screens
22:09	namra	justin_smith: yes those are the key commands. but they don't work as commands.
22:09	justin_smith	oh, I misunderstood
22:09	arrdem	Bronsa: got a minute to look at the ns-publics TANAL tree with me? trying to understand what the desired output bytecode is.
22:10	Bronsa	arrdem: yeah sure
22:11	arrdem	Bronsa: https://www.refheap.com/107106 trimmed tree of only the relevant lambda
22:12	Bronsa	arrdem: are you trying to understand why temjvm explodes on ns-publics?
22:13	arrdem	Bronsa: da
22:13	arrdem	and fix...
22:13	Bronsa	arrdem: I thought I already mentioned the reason
22:13	Bronsa	arrdem: it's not an analysis bug
22:13	arrdem	Bronsa: maybe last year I didn't find it in my notes.
22:14	Bronsa	arrdem: no i mean, I remember mentioning it like 3 days ago in slack I might have not highlighted you though
22:14	arrdem	Bronsa: yeah I don't remember that
22:15	Bronsa	arrdem: look at the source code for ns-publics -- it's something like (fn [^Var v] (if (instance? Var v) (.something v)))
22:15	arrdem	Bronsa: yep
22:15	arrdem	Bronsa: I get what's going on here, my real question is "is there something silly we could/should do so this just works"
22:16	Bronsa	arrdem: the only way to fix this is to change the emitter to emit "untyped" locals like Compiler.java does so that type hints are not enforced
22:17	arrdem	Bronsa: gotcha. OK.
22:17	Bronsa	arrdem: can't estimate how much work that'll be. might be tricky
22:18	arrdem	Bronsa: but for that it'd get us another step towards CinC I can't honestly say it's a feature
22:19	arrdem	or rather but that
22:19	Bronsa	err, what?
22:20	arrdem	there is no point to that change but to make loading core work
22:20	Bronsa	yeah
22:20	arrdem	tempted to special case the eval of that AST to eval a less silly AST...
22:21	Bronsa	arrdem: I mean, clojure.org explicitely states that type hints are not enforced so I take the blame for this
22:22	arrdem	Bronsa: yeah. OK. I'll take a look at this and see what I can do while remaining a Clojure compiler.
22:22	Bronsa	(I still think that there's no good reason not to enforce type hints)
22:22	namra	justin_smith: one could specify the absolute line number. i.e. in command mode just type the line number and the cursor will jump to it
22:22	arrdem	you and me both
22:23	arrdem	but if we ever figure out how to do emitter configs that's something a user could toggle
22:23	Bronsa	yes
22:23	arrdem	s/emitter configs/modular emitters/g
22:24	arrdem	any thoughts on that? I threw some stuff at the wall but nothing I thought would really be performant.
22:24	arrdem	kinda tempted to prioritize usability over perf
22:24	Bronsa	this particular use case could even be done as an AST rewrite without touching the emitter I think
22:24	Bronsa	rewrite pass*
22:24	arrdem	I mean you just drop the local tags or retag to Object
22:25	arrdem	which we could do by default...
22:25	Bronsa	yeah, and move the cast to the interop point
22:26	arrdem	right that's what I was going to try. don't do any casting or typing until you interop and then checkcast.
22:26	Bronsa	that's what compiler.java does, yeah
22:26	arrdem	simplest stupidest thing that could possibly work...
22:26	Bronsa	has the disadvantage of requiring a checkcast for every interop form
22:27	arrdem	so one thing I've been thinking about is that the JVM bytecode we emit really hides the stack as a dataflow graph
22:27	arrdem	don't know how to do this yet, but given a dataflow representation of generated code fixing stuff like that is dead easy
22:27	Bronsa	arrdem: depending on how bored I get next week I might try and refactor/rewrite the casting/boxing mess in t.a.jvm
22:28	arrdem	Bronsa: please do, it'll probably improve my test coverage as well <3
22:28	arrdem	anyway I'm gonna keep banging on cleaning up the emitter for fun
22:29	arrdem	hopefully I'll get to try profiling the new flatten stuff soon but I'd like to clear the current bug list before potentially introducing more with that
22:30	arrdem	so if there are others I should know about speak now :P
22:31	TEttinger	yaaaay bug fixes
22:31	Bronsa	arrdem: other than the reflector stuff in the analyzer, I'm not aware of any other
22:33	Bronsa	arrdem: btw re the emitter, it would be interesting to know how much time is spent building up the bytecode data structure vs how much time it's spent traversing it & emitting actual bytecode
22:34	arrdem	Bronsa: I seem to recall from your previous investigations that we're wasting a _lot_ of time in concat right now.
22:34	arrdem	Bronsa: hence the flatten stuff that does a single pass loop unrolled conj! with no intermediary datastructures
22:34	Bronsa	yeah, that definitely dominates time
22:35	TEttinger	uh, is this the flatten that is
22:35	TEttinger	~flatten
22:35	clojurebot	flatten is rarely the right answer. Suppose you need to use a list as your "base type", for example. Usually you only want to flatten a single level, and in that case you're better off with concat. Or, better still, use mapcat to produce a sequence that's shaped right to begin with.
22:35	arrdem	TEttinger: no this is my own flatten impl that is more domain specifi
22:35	arrdem	*c
22:35	TEttinger	cool
22:35	TEttinger	I wouldn't bother to optimize clojure.core/flatten
22:36	arrdem	TEttinger: https://github.com/clojure/tools.emitter.jvm/blob/054873c0f1e553c9941b4675b31b42d8c1eed654/src/main/clojure/clojure/tools/emitter/jvm/emit.clj#L66
22:36	Bronsa	but if the time spent traversing/transforming is still significant it might mean that we need to rethink the emission thing alltoghether -- maybe the current representation is just too expensive?
22:36	arrdem	yeah who knows. only way to find out is to benchmark that thing.
22:37	arrdem	which involves rewriting half the bloody emitter to avoid `~@ concats
22:37	TEttinger	unicode! who put unicode in this code! (λ AST → Options) → Bytecode
22:37	Bronsa	yup
22:37	arrdem	that would be me
22:37	arrdem	like.. last yeart
22:37	arrdem	*year
22:37	TEttinger	arrdem, but that's Scala's turf
22:38	TEttinger	you'll start a gang war
22:38	arrdem	TEttinger: FITE ME U NERD
22:38	arrdem	I like my type signature docstrings thnx
22:38	TEttinger	http://scalaz.github.io/scalaz/scalaz-2.9.0-1-6.0.1/doc.sxr/scalaz/Kleisli.scala.html
22:38	TEttinger	I have that bookmarked under IDEAL SCALA CODE
22:39	TEttinger	intuitive and clear.
22:39	TEttinger	def <=<[C](k: C => M[A])(implicit b: Bind[M]): Kleisli[M, C, B] = ☆(k) >=> this
22:39	TEttinger	it hurts me.
22:40	arrdem	Bronsa: you still using those UTF8 rewrite rules you gave me last summer?
22:41	arrdem	Bronsa: and yeah I don't know what we'll have to do if this representation is just too slow.
22:41	arrdem	I want to play with building a data flow model for JVM bytecode that we can use as yet another intermediary target for writing a real peephole optimizer, but that's a ways out.
22:44	Bronsa	arrdem: haven't changed my emeacs setup in years
22:44	Bronsa	i know those rewrite rules mess with how my code is indented but I kinda sorta don't really care :P
22:45	arrdem	Bronsa: this typifies your code style yes :P
22:46	Bronsa	arrdem: yeah. the current representation doesn't really buy us that much over directly emitting bytecode
22:47	arrdem	Bronsa: I mean... I love TEMJVM just for the existing representation because it's a friggin clojure datastructure I can muck with and understand, but yeah we could build something good for a lot more leverage.
22:47	arrdem	Bronsa: I think the unchecked locals patch is gonna be dead easy, just a sec
22:48	Bronsa	it was definitely invaluable when writing it. Couldn't imagine debugging emission bugs without the data representation
22:49	Bronsa	but i'm not too sure it's the best approach. doesn't buy us enough benefits to justify the performance hit
22:49	arrdem	I would have given up on Oxcart but for it...
22:49	Bronsa	dunno. I'd like to be happy with the analyzer infrastructure before investing time refactoring/rewriting the emitter
22:49	arrdem	Bronsa: I mean I think anything else we do would be a sources as leafs dataflow graph
22:50	arrdem	so you have a tree of ops which have nth things on the stack which will be popped as children
22:51	arrdem	your sources being constants and ILOADs
22:51	arrdem	and your sinks being pops whether implicit or explicit
22:52	arrdem	this would let you consider ops like checkcast to be pop 1 push 1 adding metadata, and now you can walk the dataflow path backwards to eliminate duplicate casts.
22:52	arrdem	^ this being the reason that I'm messing with any of this again actually
22:53	Bronsa	right, and stuff like intrinsics could be implemented in a less hackish way than it is now
22:57	arrdem	interestingly the flatten stuff gets us part of the way there...
22:58	arrdem	if you squint really hard at the "can force thunks of 0 arguments" case
23:02	Bronsa	going to sleep now
23:03	arrdem	g'night thanks as always
23:05	mtamrf	what's an idiomatic way to express a nested for loop with side effects (dosync)?
23:13	arrdem	mtamrf: can doseq not do what you need?
23:13	arrdem	mtamrf: note that doseq can go over multiple sequences and supports all of for's sequence expressions
23:14	justin_smith	mtamrf: dosync is for refs, you are likely thinking of doseq? or do you want a doseq of dosyncs? that almost sounds like a doctor seuss poem
23:14	justin_smith	(doc dosync)
23:14	clojurebot	"([& exprs]); Runs the exprs (in an implicit do) in a transaction that encompasses exprs and any nested calls. Starts a transaction if none is already running on this thread. Any uncaught exception will abort the transaction and flow out of dosync. The exprs may be run more than once, but any effects on Refs will be atomic."
23:18	mtamrf	typo - I did mean doseq
23:22	arrdem	aaand bronsa no longer idles on a proxy ok
23:23	arrdem	whelp I think I found a two local fix to that issue rather than some huge rewrite..
23:33	TEttinger	nice arrdem
23:39	gganley	are there any meetups in MA that is should know about?
23:42	arrdem	aaaand Stackmap issues
23:42	arrdem	fml
23:43	arrdem	TEttinger: yeah turns out not checking casts is pretty easy :P