#clojure – 2014-09-11

2014-09-11

00:01	wildnux	is this the idiomatic way of applying a function to every elements in a nested list?
00:01	wildnux	(map #(apply * %) [[1 2 3] [4 5 6]])
00:01	wildnux	this works, are there any other better way to achieve this?
00:01	justin_smith	,(map * [1 2 3] [4 5 6])
00:01	clojurebot	(4 10 18)
00:02	justin_smith	,(apply map * [[1 2 3] [4 5 6]])
00:02	clojurebot	(4 10 18)
00:03	justin_smith	or wait - you want (* 1 2 3) and (* 4 5 6)
00:03	wildnux	justin_smith: I want function to apply to each each element of the outer list (apply funtion to nested list)
00:03	wildnux	justin_smith: so that it should give (6 120)
00:03	justin_smith	right, so #(apply * %) is the best option
00:03	wildnux	ok
00:03	wildnux	,(map #(apply * %) [[1 2 3] [4 5 6]])
00:03	clojurebot	(6 120)
00:04	justin_smith	though #(reduce * %) would also give the right answer
00:05	wildnux	now, if i wanted to get the max of the resulting elements i could do
00:05	wildnux	,(max (map #(apply * %) [[1 2 3] [4 5 6]])
00:05	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading>
00:05	wildnux	,(max (map #(apply * %) [[1 2 3] [4 5 6]]))
00:05	clojurebot	(6 120)
00:05	justin_smith	I think you want apply max
00:05	wildnux	,(reduce max (map #(apply * %) [[1 2 3] [4 5 6]]))
00:05	clojurebot	120
00:05	justin_smith	yeah, apply max and reduce max would both work
00:06	wildnux	i could do that, now, my question is how do i get that list [4 5 6] because of which 120 (max) was returned
00:06	justin_smith	,(apply max (map #(apply * %) [[1 2 3] [4 5 6]]))
00:06	clojurebot	120
00:06	wildnux	is there a way to get that list which has max product?
00:06	justin_smith	max-key
00:07	justin_smith	,(max-key #(apply * %) [1 2 3] [4 5 6])
00:07	clojurebot	[4 5 6]
00:07	justin_smith	and again, if the args are all in one list, you can use apply, of course
00:08	justin_smith	,(apply max-key #(apply * %) [[1 2 3] [4 5 6]])
00:08	clojurebot	[4 5 6]
00:08	justin_smith	clojure is magical
00:08	wildnux	justin_smith: awesome :)
00:08	wildnux	this is sooo cool
00:09	wildnux	justin_smith: extending this, is there a funtion which takes any function instead of 'max' in max-key?
00:09	justin_smith	(first (sort-by f l))
00:09	justin_smith	l being a sequence
00:10	wildnux	aah ok
00:11	justin_smith	and f should give the most qualified item the lowest score
00:11	justin_smith	otherwise you have to walk the whole sequence at the end
00:11	justin_smith	you could also optimize that with a reduce
00:11	justin_smith	(in order not to build a collection you don't really need)
00:14	justin_smith	,(reduce (fn [[score mx] e] (let [s2 (count e)] (if (> s2 score) [s2 e] [score mx]))) [0 nil] ["hello" "this" "is" "sort by count"])
00:14	clojurebot	[13 "sort by count"]
00:15	justin_smith	appropriate if you don't want to call your f more than once per item, and don't want to build the whole ordered collection
02:01	dorkmafia	i copied my directory over to another computer then tried to run lein repl on it and now i'm getting this error: Exception in thread "main" java.lang.UnsupportedClassVersionError: org/jivesoftware/smack/Roster : Unsupported major.minor version 51.0
02:01	amalloy	dorkmafia: your version of java is too old
02:01	dorkmafia	oh yes
02:01	amalloy	i forget what 51 means, but i think it means you need 7 and have 6-
02:01	dorkmafia	thank u
02:01	dorkmafia	yup
02:02	dorkmafia	makes sense i forgot about that
02:03	dorkmafia	do i need the jre and jdk? or just the jdk?
02:04	beamso	jdk
02:07	dorkmafia	so I'm wrapping this xmpp lib and a lot of things require me to pass the connection to my functions I get the connection when the user logs in is a way for me to store in a def?
02:08	dorkmafia	there*
02:09	beamso	you could store the connection in an atom
02:14	dorkmafia	oh cool how would i do that? :B
02:15	beamso	something like (def conn (atom <however you established your connection>))
02:15	beamso	http://clojure.org/atoms
02:18	dorkmafia	ok cool thanks i'll check it out
02:28	yedi_	i'm making a metronome webapp, so timing is hugely important. it seems that there is some lag when using timeout. e.g: https://gist.github.com/yedi/1abcdf0d8675fd532eca
02:29	yedi_	there seems to 2-3 milliseconds of lag when using timeout (it jumps up to about 6-7 ms of lag in my actual application)
02:29	yedi_	is there anyway to nullify or account for this lag? or is there a better way to handle timing in clojurescript?
02:30	beamso	javascript isn't threaded
02:30	yedi_	right
02:31	beamso	i think even if it was threaded you would see the timeout being longer than the exact 1000 that you're looking for
02:31	yedi_	know of a better way?
02:33	yedi_	i guess i could try to test / calculate the lag and then adjust the timing based off of that. but it seems like that could get messy / won't be perfect either
02:39	beamso	i found this : http://www.sitepoint.com/creating-accurate-timers-in-javascript/
02:40	beamso	basically they are running a shorter timeout and adjusting by the difference in intended and actual timeout they encounter
02:47	piranha	beamso: in reality you don't even need to adjust anything, just check what time is it now. Plus it may be worth it having a setTimeout instead of setInterval so you can try to ask for a shorter delay if you need that
02:47	piranha	on the other hand, you can just have very short (1-5ms) interval and not worry about it, I guess
02:47	piranha	but that still could backfire if the system is a bit overloaded :(
02:47	beamso	okay
02:48	piranha	ah, that's what they are doing (adjusting the timer) - didn't read till the end
02:49	piranha	beamso: plus I see you're using async channels, and I think it could a bit of it's own overhead
02:49	piranha	maybe it's worth to to stick with primitives in your case...
02:49	beamso	i should be using async channels, but i need to learn about them.
02:49	beamso	it was yedi_'s gist
02:50	piranha	beamso: I need to drink coffee before I look into a clojure channel, I'm sorry :)
02:50	piranha	yedi_: ^
02:51	beamso	not a problem.
02:52	yedi_	ah thanks guys
02:52	yedi_	i'll try using primitives before just going with the 'figure out the time difference and change timeout accordingly approach)
02:52	yedi_	though i just love using core.async for everything
02:52	yedi_	makes me feel nice n fuzzy inside
02:53	piranha	it does :)
02:53	piranha	but in this case you want to get least amount of layers between a cpu and your code, and you've got js already :)
02:54	piranha	no need to add core.async on top for it to be not exactly real time :)
04:36	magopian	can someone please point me at some docs on the "volatile!" function? can't find any :/
04:55	maxthoursie	magopian: https://github.com/clojure/clojure/blob/42f68bc7688db3a24565dfcdc1cba92dd8a99159/src/clj/clojure/core.clj#L2390
04:55	maxthoursie	it's not exactly verbose though :)
04:56	magopian	ah :)
04:56	magopian	so what's a volatile? :)
04:56	maxthoursie	* volatiles - there are a new set of functions (volatile!, vswap!, vreset!, volatile?) to create and use volatile "boxes" to hold state in stateful transducers. Volatiles are faster than atoms but give up atomicity guarantees so should only be used with thread isolation.
04:57	maxthoursie	(from changes.md)
04:57	magopian	ok, so it's linked with transducers, that's why i see those come up from time to time (i'm trying to get my head around transducers, but still having issues atm)
04:58	maxthoursie	if I understand correctly it's just a wrapper around javas volatile
04:58	maxthoursie	they were added as they were beneficial for the implementation of transducers
04:59	magopian	ok ;)
04:59	magopian	thanks a lot for the answe r;)
04:59	maxthoursie	np
05:36	CookedGryphon	How would I write a core async buffering strategy which does a distinct-by :id just for things in the buffer but keeping order
05:36	CookedGryphon	so I have a number of overlapping events, each of which have an id
05:37	CookedGryphon	and for each event i might receive an undetermined number of updates
05:37	CookedGryphon	I want to apply backpressure, but only keeping the latest event for each ID, as each event also contains all the historical data (persistent data structures rule)
05:38	CookedGryphon	for extra credit, some way of controlling whether the order is maintained as first-id-in, or latest-id-updated
05:39	CookedGryphon	any ideas? My best so far was to create a chan per ID with a sliding buffer 1 and then merge them all, but keeping track of all that when the event ids are unlimited and constantly increasing is tricky
05:45	gws	CookedGryphon: you could write your own buffer that implemented your strategy (maybe using a set for testing membership?) - see this for inspiration https://github.com/clojure/core.async/blob/master/src/main/clojure/clojure/core/async/impl/buffers.clj
05:49	CookedGryphon	gws: that looks like exactly what I need, thanks a lot!
05:51	lvh	I have a list of different arguments; I want to check if (apply f args) is equal to the same constant for each of them
05:52	lvh	can I coerce core.test's "are" macro into doing that?
05:57	gws	,(apply = 42 (map (partial apply +) [[21 21] [21 21]]))
05:57	clojurebot	true
05:57	gws	,(apply = 42 (map (partial apply +) [[21 21] [21 22]]))
05:57	clojurebot	false
05:58	gws	lvh: would that do what you want?
05:58	lvh	gws: hm, maybe yes
05:58	lvh	I didn't realize apply had an & colls part in the signature
06:01	lvh	err, or more accurately that = was variadic I guess
06:02	gws	yep! and > and < and so on
06:02	gws	,(> 5 4 3 2 1)
06:02	clojurebot	true
06:03	gws	,(> 5 4 3 2 2)
06:03	clojurebot	false
06:03	gws	,(>= 5 4 3 2 2)
06:03	clojurebot	true
06:04	lvh	ack, this unfortunately doesn't help me because these are byte arrays
06:05	lvh	(so = doesn't work :()
06:06	lvh	I guess what I really want is (apply are ...), except of course that doesn't really work (I think) because are's a macro?
06:08	lvh	every? true? it is
06:26	piranha	anybody using prismatic.schema here? I'm not sure what's the best way to express "for some values of :filter, :user_id should be specified" in {:filter (s/enum ...), :user_id s/Int}
06:29	sm0ke	piranha: look at s/pred
06:29	sm0ke	you can define a function there
06:30	piranha	sm0ke: but pred only gets it's own value to check, right? in this case how do I express "true if other value is something"?
06:31	piranha	ah, it could be much more complex than that
06:31	piranha	it's just pred is greatly simplified
06:31	piranha	ok, I'll try to look into that
06:32	piranha	I actually made it work through s/either, but then error reporting becomes really obscure :\
07:13	babygau	https://www.refheap.com/ce7f89cbca4992e046c8dc50c
08:11	rurumate	Hello #clojure, I want to find all (nonempty) subsequences of given sequence a. So for example, (sublists [1 2 3]) should evaluate to '((1) (2) (3) (1 2) (1 3) (2 3) (1 2 3)). I know (comp set #(map sort %) powerset) can do it, but it seems wasteful to calculate the full powerset and then throw away all the lists that are just permutations of the same sorted list.
08:17	clgv	rurumate: then just write a recursive function that directly computes the set of all unordered combinations
08:18	clgv	rurumate: I dont know how your powerset function is implemented, but you can probably steal the general idea from it
08:35	jkj	http://stackoverflow.com/questions/22959804/inserting-postgresql-arrays-with-clojure/25786990#25786990
08:49	Kamuela	Is clojure relational/logic programming?
08:49	clgv	Kamuela: no, not the core language itself. but there is a library called core.logic that allows logic programming under clojure
08:51	Kamuela	clgv, That seems to be what I'm using with this tutorial
08:56	clgv	Kamuela: ok, so you are actually learning two things at once
08:57	Kamuela	clgv, the tutorial purports itself as an introduction to logical programming
08:57	clgv	Kamuela: yeah thats ok when they use core.logic
08:57	clgv	Kamuela: Clojure itself is mostly functional programming, though there are imperative constructs for side-effects as well
09:05	rurumate	list powerset, seems workey: https://www.refheap.com/90094
09:06	clgv	rurumate: recursive concat may blow your stack for large `xs`
09:08	clgv	rurumate: ah and non-tail recursion as well
09:13	Kamuela	clgv, what do you think of core.logic for AI?
09:17	clgv	Kamuela: I did not use core.logic, yet
09:18	clgv	Kamuela: I only read about it
09:18	rurumate	clgv: yes it would be nicer with lazy seq
09:19	rurumate	clgv: what exactly do you mean "recursive concat"?
09:20	clgv	rurumate: when you wrap concats in each other
09:21	rurumate	hmm yes seems like that's the case there
09:27	lvh	reiddraper: Hi! I'm playing with test.check for the first time. Thanks for building it.
09:28	lvh	reiddraper: I was wondering if there's a better way to get length-n byte arrays rather than (gen/fmap byte-array (gen/vector gen/byte n))
09:28	lvh	Doesn't seem like I can use "bytes" for it. Also, if that would be a good thing to contribute to test.check :)
09:32	clgv	lvh: what is the problem with that? the possible overhead due to vector construction?
09:33	lvh	clgv: no, no problem with that, except that there's already a gen/bytes that almost does what I want
09:33	lvh	clgv: and gen/vector, a pretty close cousin, can be parametrized by length
09:34	clgv	lvh: but it's exactly the same structure
09:35	lvh	clgv: Yes, I created that thing by copying bytes' implementation
09:35	lvh	clgv: I'm trying to figure out if there are clever ways to constrain the generator's output
09:35	clgv	lvh: I think you could externally control its size
09:35	lvh	reading some of the code it looks like maybe there's something like that
09:35	lvh	by clever I mean "not generating a bunch of arrays and throwing away the ones that aren'te xactly 16 bytes long)
09:36	clgv	lvh: the probably that arity impl needs to be added^^
09:37	lvh	clgv: that's what I would guess but unfrtunately right now bytes isn't even supposed to be called, it's just a constant
09:39	clgv	lvh: thats no problem. it can be easily converted to a function with both arities
09:40	lvh	clgv: wtihout breaking backwards compatibility? really?
09:40	lvh	clgv: you teach it to be a regular value and then override its IFn behavior or something?
09:40	AeroNotix	I want to run a jetty/ring handler on port 0 (random port) how would I then retrieve the port number it is using? This is for tests.
09:41	clgv	lvh: well, were is written that you are not allowed to break backwards compatibility for improvements? imho you only need to communicate that there are breaking changes
09:41	lvh	clgv: oh, okay; yeah, sure -- I guess that's an implicit question for reiddraper :)
09:42	mikerod	If we have something like: (LocalDate. 1) called, which constructor does Clojure call? LocalDate(Object) or LocalDate(long)
09:42	mikerod	I know clj numeric literals are boxed Long by default
09:43	mikerod	but does the Compiler automatically cast it as primitive to call the LocalDate(long) in case like this? Perhaps this is a dumb question, but I'm a bit unclear how this part works.
09:52	clgv	mikerod: set warn-on-reflection on true and see what it tells you
10:10	mikerod	clgv: I have that set and it doesn't say anything
10:12	lvh	is https://github.com/paraseba/lein-reload still the thing I use if I want my tests to be constantly run?
10:13	pjstadig	lvh: https://github.com/jakemcc/lein-test-refresh is actively maintained
10:15	lvh	pjstadig: thanks!
10:15	clgv	mikerod: I'd vote for LocalDate(long) when you pass the primitive long - you can check via a decompiler.
10:16	mikerod	clgv: Do you mean when I specifically "ask" for a primitive though? Yes, I think I'll go to the decompiler for this one.
10:17	bbloom	Bronsa: did you ever get around to looking in to jvm mechanisms for chaperons etc?
10:26	clgv	bbloom: what is a chaperon?
10:27	bbloom	clgv: racket stuff for meta-object protocol voodoo for checking contracts and other things dynamically via object proxies
10:27	clgv	bbloom: uh ok.
10:28	bbloom	clgv: http://docs.racket-lang.org/reference/chaperones.html
10:33	ToxicFrog	So, with core.typed, I'm having two weird issues. I haven't added any type annotations yet, just enabled checking for a few namespaces in preparation.
10:33	ToxicFrog	The first issue is that ns spellcast.core has (require '[taoensso.timbre :as log]) and then calls some things as log/foo ..., and this produces a 'no such namespace: log' message.
10:34	ToxicFrog	I also get a 'not checking spellcast.game: tagged :collect-only' -- but there's no such tag.
10:36	jlongster	what is the use case for the transformation function in `transduce` taking in the final result of the transformation? https://github.com/clojure/clojure/blob/master/src/clj/clojure/core.clj#L6521
10:37	dnolen_	jlongster: it's the completion step
10:37	tbaldridge	jlongster: consider starting with (transient x) and ending with (persistent! x)
10:38	dnolen_	jlongster: you imagine also imagine reducing over a resource like a file and closing it in the completion step
10:38	jlongster	dnolen_: tbaldridge: huh, interesting. thanks. I can see that
10:38	bounb	anyone got a copy of rhickey's chunked sequences talk?
10:39	ToxicFrog	Hmm. refer :all and (use) are just scope hacks, right? They don't actually change the contents of the current namespace?
10:44	llasram	ToxicFrog: The opposite actually. All `refer`ing (include `:all`) modifies the `refer'ing namespace to map the name symbols to the target vars
10:45	ToxicFrog	llasram: huh. So if ns A refers, say, clojure.core.typed/ann, and ns B requires A, B can then call A/ann?
10:51	llasram	ToxicFrog: I believe that is actually the case, yes
10:51	CookedGryphon	only if they fully qualify it though
10:52	llasram	Most tooling (and stdlib functions?) ignores vars which don't belong to the namespace refering them, but the namespace itself refers to the var
10:55	llasram	Oh, nevermind -- I'm confused. Half of what I said is true, but namespaces differentiate between "interning" and "refering"
10:55	llasram	Well, kind of.
10:56	llasram	No, they don't. Ok, so you can't say A/ann, but only because there's a check on lookup of `ann` in `A` to verify that the namespace of the var found for `ann` is the same namespace
10:58	llasram	https://github.com/clojure/clojure/blob/master/src/jvm/clojure/lang/Namespace.java#L195-L200
10:59	llasram	But the actual mechanics of what is stored in the namespace are identical for vars which "belong" to the namespace vs referred from others
11:00	justin_smith	llasram: woah, a validating sanity check, in Clojure? astounding news
11:00	justin_smith	I kid because I love
11:01	ToxicFrog	llasram: aah. Honestly that kind of seems like the worst of both worlds~
11:10	mikerod	Does anyone know where the notation used in the Java specs is defined? Such as what <: means?
11:10	mikerod	I don't see it anywhere, it just starts being used...
11:10	mikerod	or <<
11:10	mikerod	I think I have a guess what they are meaning, but it'd be nice to have clarification
11:11	clgv	mikerod: reserved names or something like that?
11:12	justin_smith	mikerod: is it documented somewhere around here? http://docs.oracle.com/javase/8/docs/api/
11:12	clgv	mikerod: http://docstore.mik.ua/orelly/java-ent/jnut/ch02_05.htm
11:14	justin_smith	mikerod: do you have a link to a page using this notation you are unsure of?
11:33	mikerod	clgv: justin_smith ok to clarify, I'm not referring to Java language syntax
11:34	mikerod	I'm referring to notation used to describe the Java specs
11:34	mikerod	justin_smith: example: http://docs.oracle.com/javase/specs/jls/se7/html/jls-15.html#jls-15.12.2.2
11:35	mikerod	Notation like "Ai << Fi (1 ≤ i ≤ n) "
11:35	mikerod	what is "<<"
11:35	mikerod	Or "Ai <: Si "
11:35	mikerod	What is "<:"
11:35	mikerod	I do not see a page in the specs that introduce what these notations mean.
11:35	mikerod	So apparently they have some more global meaning, but I don't know where that is defined.
11:36	justin_smith	≤ is the mathematical less than or equal to
11:36	mikerod	Even better: " Ul <: Bl[R1=U1,...,Rp=Up]" I'm not 100% sure I know what the square brackets are here "[" "]"
11:36	justin_smith	is that what you mean by <:
11:36	justin_smith	maybe it displays differently in my browser
11:36	justin_smith	oh never mind, now I see it
11:37	mikerod	Yeah it is a less-than and a colon
11:37	mikerod	I don't think I have a browser issue, it seems like it intended to mean something
11:37	justin_smith	yeah, I found it
11:37	mikerod	it is about being a subtype of another type I'm sure
11:37	justin_smith	I just asked a mathematician friend, on the off chance he would recognize it from somewhere...
11:37	mikerod	but I see nothing specific about this notation and it used throughout the specs
11:38	mikerod	and google searching for this notation is not so good :P
11:38	justin_smith	right
11:39	justin_smith	I bet it means something like inherits from / subtyping
11:39	mikerod	yeah, I'd like to know the difference between "<:" and "<<"
11:39	justin_smith	or derives
11:39	mikerod	and some specifics on this bracketed "Bl[R1=U1 <etc>]" notation
11:40	mikerod	I just think it is frustrating and would have expected it to be defined somewhere :P
11:40	justin_smith	mikerod: click the footnotes!
11:40	justin_smith	there are hypertext footnotes on the rules that explain the notation
11:40	mikerod	There was even http://docs.oracle.com/javase/specs/jls/se7/html/jls-1.html#jls-1.3 but no good
11:40	mikerod	oh
11:41	justin_smith	"U << V indicates that type U is convertible to type V by method invocation conversion"
11:41	mikerod	I don't see what to click on
11:41	justin_smith	". We write T <: S to indicate that that the subtype relation holds between types T and S."
11:41	justin_smith	there are footnote links near each item
11:42	mikerod	ah
11:42	mikerod	http://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.10
11:42	mikerod	like that
11:42	justin_smith	mikerod: also, you can control-f here https://en.wikipedia.org/wiki/List_of_mathematical_symbols for things like <:
11:42	mikerod	justin_smith: awesome
11:42	justin_smith	though that does not have <<
11:42	mikerod	problem solved hah
11:43	justin_smith	oh it has ≪ instead - thanks unicode!
11:43	mikerod	,(inc justin_smith)
11:43	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: justin_smith in this context, compiling:(NO_SOURCE_PATH:0:0)>
11:43	justin_smith	you may not want the , there :)
11:43	mikerod	(inc justin_smith)
11:44	lazybot	⇒ 76
11:44	mikerod	oh, I didn't realize taht's how that one worked haha
11:44	justin_smith	it's a pseudo-clojure bot command
11:44	mikerod	I see
11:46	mikerod	Well now the Java specs are much more fun to read.
11:46	justin_smith	as in "not 100% bewildering"?
12:44	izirku	hi all! is there a predicate to check if something is an atom
12:45	justin_smith	atom?
12:45	justin_smith	oh, I thought that existed, I guess not!
12:45	llasram	,(instance? clojure.lang.Atom (atom 0))
12:45	clojurebot	true
12:45	justin_smith	there you go
12:46	izirku	aha! you just saved my life!
12:46	TimMc	phew
12:46	TimMc	I'm glad you didn't die.
12:47	izirku	coming from CL, it's still a bit foreign, but I'm adjusting. Thank you all once again!
12:48	justin_smith	izirku: nb this is not "atom" in the sense cl calls something atomic
12:48	justin_smith	izirku: but I assume you allready knew that
12:49	izirku	justin_smith: yes, I know, I just needed a check if I needej to (deref place) in my macro if it's an atom :)
12:49	llasram	Scary
12:49	tadni_`	On a related note, what does Clojure call small the equivialant of a stereoptypical "Lisp Atom"?
12:50	noonian	it would be nice if there was an atomic? fn, but it doesnt come up as much since clojure collections are immutable whereas it mattered more in cl and scheme since they were mutable
12:50	technomancy	tadni_`: I think "atom" means different things in lisp depending on how far back you go
12:50	technomancy	it used to be a synonym for symbol iirc? erlang uses that terminology.
12:51	technomancy	but I think the term you're looking for is scalar
12:51	noonian	i like the little schemers definition
12:51	technomancy	(meaning not compound)
12:51	noonian	yeah
12:51	justin_smith	technomancy: so numbers and other primitives were not atomic?
12:51	tadni_	technomancy: I've always known it as a term for things that are indivisible.
12:52	tadni_	Numbers, strings, some single charecters like "*".
12:53	justin_smith	but numbers and strings are divisible into bits and chars...
12:53	bbloom	atomic or scalar is a matter of perspective :-)
12:53	tadni_	justin_smith: Well yeah, not my metrics though really.
12:54	tadni_	Kinda just what lisps, or at least Emacs Lisp intro quantifies.
12:54	technomancy	justin_smith: depends how far back you go iirc
12:55	dagda1_	what does this type of expression mean (into {} *1)
12:56	dagda1_	it is in the docs for map http://clojuredocs.org/clojure_core/1.2.0/clojure.core/map
12:57	hiredman	*1 is bound to the result of the last expression in the repl
12:57	technomancy	justin_smith: this seems to consider numbers and atoms distinct: http://www.softwarepreservation.org/projects/LISP/book/Weismann_LISP1.5_Primer_1967.pdf
12:57	TimMc	izirku: You can also check if something is an IDeref
12:58	TimMc	izirku: Why does your macro care if something is an atom?
12:58	izirku	TimMc: IDeref?
12:58	justin_smith	dagda1_: look at (doc into)
12:59	justin_smith	*1 means "the last result evaluated in the repl session"
12:59	dagda1_	justin_smith: k
13:00	izirku	TimMc: it's a PeopleSoft specific DSL wrapper on top of Korma. When I have an WHERE setid IN (...) ..
13:00	TimMc	&(map (partial instance? clojure.lang.IDeref) [(atom 0) (future 5) (promise) (var +) (delay 4) :abc])
13:00	lazybot	java.lang.SecurityException: You tripped the alarm! future-call is bad!
13:00	TimMc	,(map (partial instance? clojure.lang.IDeref) [(atom 0) (future 5) (promise) (var +) (delay 4) :abc])
13:00	clojurebot	#<SecurityException java.lang.SecurityException: no threads please>
13:00	TimMc	anyway
13:00	noonian	yeah, *1 only means something in the repl, its not normal clojure magic syntax
13:00	noonian	,(+ 2 4)
13:00	clojurebot	6
13:00	noonian	,*1
13:00	clojurebot	#<Unbound Unbound: #'clojure.core/*1>
13:00	justin_smith	noonian: *1 does not work with clojurebot, each command is a new repl
13:00	izirku	TimMc: my values for IN are stored in an atom, I'm had to make sure I do deref it
13:00	noonian	i see
13:01	noonian	&(+ 1 1)
13:01	lazybot	⇒ 2
13:01	noonian	&*1
13:01	lazybot	⇒ #<Unbound Unbound: #'clojure.core/*1>
13:01	justin_smith	so "the last value returned by the repl" is unbound
13:01	noonian	shrug
13:01	justin_smith	yeah, it's inconvenient
13:01	justin_smith	,(do 1 *1)
13:01	clojurebot	#<Unbound Unbound: #'clojure.core/*1>
13:01	izirku	TimMc: it works now. Thanks for the IDeref explanation, will come in handy!
13:01	TimMc	izirku: Oh, this is for the code the macro emits, not the macro's own processing.
13:03	izirku	TimMc: yes, you are right on target :)
13:07	yedi	is there a built-in data structure for / what's the best way to create a sliding queue with a size limit. (where new elements pop off old ones when the limit has been reached)
13:08	yedi	could just create a function for appending to a list, that also pops out the other end but I was wondering if there was a more elegant way
13:13	justin_smith	yedi: so a dequeue?
13:13	yedi	lemme google
13:13	justin_smith	https://github.com/pjstadig/deque-clojure
13:13	justin_smith	a deque is a queue that supports efficient addition or removal from either end
13:14	hiredman	there is no built in immutable sliding queue, there is a queue, and building a sliding queue from that can be as simple as checking the size and poping when you add an item if the "size" would overflow your bounds
13:15	noonian	core async channels can use sliding buffers, i'm not sure what your use case is but that might be more appropriate if you're comfortable with core async
13:15	bbloom	core async's buffers are mutable
13:15	hiredman	right
13:15	hiredman	not values
13:19	noonian	yep, but yedi didn't say anything about what he wanted it for
13:19	yedi	i need to record a bunch of things in real time, but I only will ever care about the last 10 things recorded
13:20	hiredman	well, he asked about built in data structures, and those are all values
13:20	yedi	ty hiredman, that's what i'll go with most likely
13:22	justin_smith	I keep forgetting about clojure.lang.PersistentQueue - it would be nice to have a literal syntax for it
13:22	justin_smith	maybe #[]
13:22	justin_smith	seems a natural fit
13:23	technomancy	$google clojure queuefish
13:23	lazybot	[fogus: So long, and thanks for all the :-)-] http://blog.fogus.me/2012/07/27/so-long-and-thanks-for-all-the-queue-fish/
13:23	hiredman	queue fish!
13:25	justin_smith	https://groups.google.com/forum/#!topic/clojure-dev/GQqus5Wycno a convo about queue-fish
13:27	stuartsierra	http://dev.clojure.org/jira/browse/CLJ-1078 and http://dev.clojure.org/jira/browse/CLJ-976
13:31	justin_smith	I think queues are good enough for something like #[] instead of #queue []
13:35	bbloom	justin_smith: i've needed an immutable queue a handful of times at most, and not once did i ever need a non-empty literal queue
13:35	bbloom	justin_smith: seems pointless to dedicate syntax to that
13:38	technomancy	#q/ueue [] ; <- technically namespaced
13:39	hiredman	#q/u
13:39	hiredman	bbloom: it would be nice to at least have a function that returns an empty one
13:41	bbloom	hiredman: yup
13:42	hiredman	(by which I mean, that is a good point about the non-empty бизнес
13:42	hiredman	)
13:49	dorkmafia	(defn foo [bar] ... ) (defn foo [baz] ... ) is this allowed in clojure two methods with the same name but different inputs?
13:49	jcsims	no - there's no way for the runtime to differentiate between them
13:50	dbasch	dorkmafia: if you want polymorphism, take a look at multimethods
13:51	dorkmafia	cool is there a way to talk to python from clojure? (I should probably google it)
13:53	justin_smith	dorkmafia: what are your constraints? can you talk to it via the network? can it be the version of python that runs in the jvm?
13:54	dorkmafia	which version of python runs in the jvm? 2.7?
13:54	justin_smith	http://www.jython.org/
13:54	dorkmafia	they will both run on the same box
13:55	justin_smith	yeah, looks like they have a 2.7
13:55	dorkmafia	cool beans
13:55	justin_smith	well, with the jvm version it would be in the same process, and won't be able to use C bindings (with all the advantages and disadvantages that these imply)
13:56	justin_smith	(or maybe some C bindings, but it would be via jni or something similar)
13:56	justin_smith	*could be in the same process
13:56	justin_smith	I just picked that as an example as that is the tightest you could bind the two that I know of
13:56	justin_smith	while talking on a socket is a very loose binding between the two
13:57	dorkmafia	well i was just going to try and get skype4py working since the skype4java that I tried before had issues
13:58	technomancy	dorkmafia: hylang.org might be better for that
13:58	technomancy	I have had luck in the past communicating with skype over dbus
13:58	technomancy	fsvo "luck"
13:59	dorkmafia	heh
13:59	technomancy	as much as anyone with the misfortune of having to use skype for nontrivial things can be said to have luck, I mean
14:06	stw	I'm using a future to run a third party java library with a timeout, when it times out because the 3rd party library fails the memory and cpu usage remain, what is the best way to isolate this third party call in clojure or to kill it off if it times out? I've looked everywhere, tried future-cancel to no avail
14:07	justin_smith	stw: what about putting the in its own vm, and shutting that process down as needed?
14:08	stw	I was thinking about that, wasn't sure if there was a more idiomatic solution
14:08	stw	in another language I would certainly fork a process for it
14:08	vanila	hi
14:09	SegFaultAX	Unfortunately that's a /really/ heavyweight solution.
14:09	vanila	I've been looking at nanopass frameworkf for making compilers
14:09	vanila	just wondering if anyone knows other modern compiler building tools?
14:09	stw	SegFaultAX: yes, any other ideas?
14:10	SegFaultAX	stw: Is the library still maintained? Is it open source?
14:12	stw	SegFaultAX: open source yes, maintained, doesn't look like it - contacted the author a while back to see if he was interested in making changes for me, but he wrote back that he's moved on
14:12	SegFaultAX	I'm wondering if it's practical to patch the library to make it behave better or even support timeouts natively for whatever it's doing.
14:12	SegFaultAX	stw: Well if its OSS, you could just fork it and make the changes yourself. Is that a reasonable solution?
14:12	stw	Yes, that's a good thought, I may need to wrap the 3rd party method call
14:13	SegFaultAX	Out of curiosity, what library is it?
14:13	stw	SegFaultAX: yes, thats a good idea and I've already made some customizations to it, it's daisydiff https://code.google.com/p/daisydiff/
14:14	SegFaultAX	Whoa, that's pretty cool.
14:14	dorkmafia	technomancy: yah skype is horrid
14:14	stw	SegFaultAX: works well most of the time, gets hung up on some inputs
14:15	technomancy	dorkmafia: at my last job it was used for multi-user chat ಠ_ಠ
14:15	technomancy	like, text chat
14:15	dorkmafia	yes thats what we use it for toO!
14:15	dorkmafia	cause who cares about security!
14:16	technomancy	my condolances
14:16	technomancy	https://github.com/dakrone/skyyy this is a thing
14:16	SegFaultAX	stw: Neat, what kinds of edge cases have you found?
14:17	SegFaultAX	technomancy: You still at Heroku?
14:18	stw	SegFaultAX: in the limited time I've been using it, tables don't work out so well, adds a lot of new lines, but for the most part pretty good
14:18	technomancy	SegFaultAX: yeap
14:18	SegFaultAX	stw: Does it do some kind of semantic evaluation of the DOM?
14:18	SegFaultAX	technomancy: It's all IRC there, yea?
14:18	stw	SegFaultAX: we pre-process the html before processing with this
14:19	technomancy	SegFaultAX: sadly no; we are on hipchat. but it can be bridged to IRC without too much fuss.
14:19	bbloom	technomancy: what, no chatter? ;-)
14:19	SegFaultAX	We also use HipChat. The most recent UI update is just all kinds of terrible. :(
14:19	technomancy	bbloom: haha, we are lucky enough to be fairly insulated from that
14:20	technomancy	SegFaultAX: I wouldn't know; I use bitlbee =)
14:20	technomancy	SegFaultAX: can't recommend it strongly enough http://www.phase2technology.com/blog/using-hipchat-through-an-irc-client-with-bitlbee/
14:21	SegFaultAX	technomancy: Awesome, thanks!
14:22	catern	technomancy: that's very neat
14:22	technomancy	it gets the job done
14:22	stw	SegFaultAX: somewhat, it parses the dom and compares inline nodes from what I've looked at
14:22	catern	technomancy: i mean the skyyy thing
14:23	technomancy	oh... well, same =)
14:23	catern	fills me with internal conflict though, because it would allow nice command line usage of Skype
14:23	catern	and... I don't know how to do command line usage of XMPP/Jingle, which I prefer
14:23	SegFaultAX	stw: Seems like a cool project!
14:24	ToxicFrog	How does lein handle it when you require two libs that each require a different version of a third library?
14:24	technomancy	catern: bitlbee is nice for that
14:24	catern	technomancy: I mean the video chat part
14:24	technomancy	oh gotcha
14:24	technomancy	catern: I have just discovered http://talky.io which works reasonably well for small conversations
14:25	technomancy	all webrtc'd up
14:25	catern	meh
14:25	catern	i'm willing to inconvenience people by forcing them to make XMPP accounts :)
14:25	technomancy	ToxicFrog: whichever one is highest up the dependency graph wins
14:25	technomancy	catern: depends how badly you want to talk to them I guess
14:26	ToxicFrog	technomancy: aaaaaaaaaaaaaaa
14:26	catern	yeah, if I don't force them to make XMPP accounts I just use Google Hangouts or Skype
14:27	technomancy	catern: talky.io is nice because you can just hand out a short URL, no need for any account setup
14:27	justin_smith	how hard would it be to make the repl show a stack trace of the running thread when you use an interrupt to stop an evaluation in the repl?
14:27	AeroNotix	after running a midje test in a cider session I get a: IllegalArgumentException Wrong number of args passed to keyword: :irrelevant-return-value clojure.lang.Keyword.throwArity (Keyword.java:92)
14:27	technomancy	Hangout invitations still confuse the heck out of me and I use them almost every day
14:27	justin_smith	AeroNotix: use (pst) to see a fuller stack trace
14:28	justin_smith	see where you are calling :errelevant-return-value with 0, or more than two, args
14:28	AeroNotix	justin_smith: it's in midje code...
14:28	justin_smith	(of course :irrelevant-return-value likely came back from some function you called)
14:28	ToxicFrog	Hmm. Ok, I thought that core.typed and clj-http wanting different versions of tool.reader was causing the crashes, but apparently not.
14:29	justin_smith	My point is, see where it intersects with your code. My guess would be you are executing something it hands back to you. Or midge is fucked and you should use clojure.test.
14:29	AeroNotix	justin_smith: now I get it -- the midje syntax is a bit non-lispy
14:30	ToxicFrog	Argh. I just want to use core.typed, but I don't even know where to start figuring out what it's conflicting with.
14:32	justin_smith	AeroNotix: midje is "lispy" in the bizarro sense that rubyists call things lispy
14:32	AeroNotix	justin_smith: :)
14:34	bbloom	lispiness aside, midje is just plain harder to use than assertions
14:34	technomancy	"lispy" -> offers you enough power to do really crazy things
14:34	bbloom	hell, clojure.test is harder to use than regular assertions
14:34	noonian	i never understood ruby people calling ruby a lisp
14:34	AeroNotix	bbloom: I've started using midje, seems to integrate with CIDER/Emacs better
14:35	bbloom	AeroNotix: i find that non-trivial classes of assertions require me to look at the (poor) docs with 100% frequency
14:35	justin_smith	AeroNotix: core.test integrates with clojure better - the tests are functions, you call them and they tell you if they failed
14:35	dbasch	noonian: for the same reason people prepend "smart" to any product name
14:36	justin_smith	it's the same way Avril Lavine identifies as punk - it makes her and her fans feel cool, and the punks are all like "wat"
14:36	AeroNotix	Smart Water
14:37	justin_smith	I actually really like dumb products - I love having a phone that doesn't know what a cloud is, or how to upload my shit to one.
14:37	technomancy	I'm getting close to having a smarter keyboard than phone.
14:38	technomancy	probably just need to drop my nokia on concrete a few times
14:38	justin_smith	heh - I'm just waiting until the atreus app store comes out
14:38	technomancy	(just finished my ARM port last night)
14:38	justin_smith	very nice
14:39	justin_smith	like - make dvorjack available as a free download, but with no shift key - then allow shift as an "in app purchase" on a per-keypress basis
14:39	justin_smith	then rake in the dough
14:42	catern	whaat
14:42	catern	ctrl-m is enter and ctrl-i is tab
14:42	technomancy	mind_blown.gif
14:42	catern	i already knew ctrl-[ is escape
14:42	catern	where can I find more of these
14:43	catern	helpful things
14:43	justin_smith	catern: and ctrl-j is return (distinct from enter)
14:43	ToxicFrog	catern: man ascii
14:43	catern	ToxicFrog: huh?
14:43	justin_smith	and control-space is the null byte
14:43	ToxicFrog	catern: the capital letters on the right correspond to the control codes on the left when ctrl is pressed
14:43	justin_smith	catern: there is a unix command called "man"
14:43	justin_smith	catern: the man page for ascii has a bunch of nice info
14:44	catern	justin_smith: yeah, but I don't see any of these ctrl-[ ctrl-m ctrl-i things in it
14:44	ToxicFrog	14:43 < ToxicFrog> catern: the capital letters on the right correspond to the control codes on the left when ctrl is pressed
14:44	catern	ah
14:45	ToxicFrog	catern: e.g. 015 13 0D CR '\r' (carriage ret) 115 77 4D M <-- ctrl-M corresponds to CR, carriage return
14:45	catern	mind blown
14:46	technomancy	yeah, control codes are sent just by flipping a bit on regular ascii codes
14:46	justin_smith	catern: for example, I am sure you already knew Ctrl-D was EOT
14:47	catern	justin_smith: everything begins to make sense
14:47	ToxicFrog	justin_smith: to be fair it could plausibly also have been ETX or EM
14:48	justin_smith	fair enough
14:48	catern	do ctrl-c or or ctrl-\ fit in this at all?
14:48	dbasch	catern: back in the day computers only had the ascii charset. My TI99 used the values > 127 for graphics (e.g. horizontal line, vertical line, angles)
14:48	catern	given that they send signals
14:49	cbp	ctr-c is etx
14:49	catern	yes
14:49	catern	etx doesn't seem very sigint-ish
14:49	dbasch	catern: that depends on the shell
14:49	justin_smith	catern: your terminal translates the keycode into a signal to the currently running process
14:49	cbp	also known as 'break'
14:50	catern	dbasch: justin_smith: is it the shell or the terminal?
14:50	ToxicFrog	Yeah, I think it's just ctrl-C for Cancel
14:50	justin_smith	catern: the terminal - the keycodes work even when you exec (which makes the shell exit)
14:50	justin_smith	and it works even if the shell is not running when the keycode is sent
14:50	catern	justin_smith: so wait, emacs understands C-c keybindings by running a signal handler?
14:50	dbasch	catern: the terminal driver
14:51	justin_smith	the terminal runs the signal handler
14:51	justin_smith	err
14:51	justin_smith	n/m
14:51	justin_smith	yeah, it uses a singal handler I think :)
14:51	justin_smith	in the console
14:51	catern	weird
14:51	catern	it works, though
14:51	justin_smith	it works :)
14:52	technomancy	reading about terminals is like reading about mime encoding
14:52	technomancy	it simply increases your wonderment and awe at the fact that anything ever works
14:53	bbloom	frickin' terminals...
14:55	justin_smith	"fucking terminals, how do they work? I don't want to talk to a computer scientist, motherfuckers lying, making me pissed"
14:56	johnwalker	technomancy: what did core.typed do to you ? :(
14:56	johnwalker	woops, wrong completion
14:56	johnwalker	ToxicFrog: what did core.typed do to you ?
14:59	catern	wait so
14:59	catern	why do both Ctrl-m and Ctrl-M send CR?
15:00	ToxicFrog	johnwalker: when I lein typed check, it does this: https://gist.github.com/anonymous/c37a772c1c470b7b1812
15:00	bbloom	,(- (int \A) (int \a))
15:00	clojurebot	-32
15:00	ToxicFrog	At first I thought this was because clj-http and core.typed wanted different versions of tools.reader, but if I drop the clj-http dependency or force them both to use the same version it still happens.
15:00	bbloom	,(- (int \a) (int \A)) ; heh, positive
15:00	clojurebot	32
15:01	justin_smith	catern: the control bit and the shift bit interact oddly - I forget the details
15:01	catern	aaaieeeeeeeee
15:01	justin_smith	catern: there is no such thing as C-m - it becomes C-M
15:01	catern	AIEEEEEEEEE
15:01	johnwalker	ToxicFrog: the easiest way to check is to move the core.typed dependency before anything else in your :dependencies
15:01	bbloom	,(char 45)
15:01	clojurebot	\-
15:01	amalloy	justin_smith: is it perhaps as simple as, when there's a control bit set, everything but the bottom five bits are masked off?
15:01	bbloom	shrug
15:01	technomancy	dang, catern's been gazing into the abyss again
15:01	ToxicFrog	catern: historically, ctrl zeroes the two high bits, which includes the bit that shift sets
15:02	justin_smith	amalloy: hrm - I dunno, that sounds plausible?
15:02	johnwalker	whether there's some sort of dependencies collision. i don't have a clue why thats happening though
15:02	amalloy	sounds like basically what ToxicFrog is saying, and i imagine he knows better than i do
15:02	ToxicFrog	johnwalker: it already is.
15:02	ToxicFrog	johnwalker: and lein deps :tree is clean.
15:02	catern	technomancy: i've learned things mere mortals are not meant to know, delved to abstraction levels that hide ancient horrors, and it has driven me mad
15:02	ToxicFrog	(since removing clj-http, that is)
15:03	amalloy	speaking of ascii control codes, a while ago i started typing C-j instead of RET while editing source buffers. it's easier, really - i don't have to reach over with a pinky
15:03	catern	okay, got any reading on this subject? there's that one really long article about terminals I've seen in passing, but I haven't read it or bookmarked it..
15:03	amalloy	plus then in the repl you can use C-j to insert a newline, and RET to send a finished expression
15:03	technomancy	amalloy: it also should auto-indent out of the box
15:04	technomancy	whereas you have to configure RET to do newline-and-indent
15:04	amalloy	technomancy: i'm on such an old version of clojure-mode that RET still does, i think
15:04	amalloy	maybe i upgraded and then reconfigured it to the old behavior
15:04	technomancy	amalloy: yeah, someone complained about that (rightly, I think) and now it works the same as everyone else
15:04	amalloy	yeah, i agree it was right to make that change
15:04	technomancy	I haven't really got in the habit of preferring C-j, maybe one of these days
15:05	technomancy	I only got using C-i because I was able to remove the TAB keycap from my ergodox
15:06	ToxicFrog	johnwalker: yeah, that's the thing, I was thinking "ok, dependencies collision, I'll just remove deps until it goes away and then figure out how to fix things", but I pared it down to just clojure and core.typed and it still happened. But I know that core.typed 0.2.68 and clojure 1.6.0 are compatible because I'm using them in another project without crashing.
15:13	ToxicFrog	johnwalker: blew away ./target and it started working. I guess it wasn't rebuilding something it should have been?
15:14	johnwalker	ToxicFrog: wow that is bizarre
15:14	amalloy	AOT compilation. not even once
15:14	ToxicFrog	I'm not even using AOT for anything but uberjar.
15:15	johnwalker	i'm glad you fixed the issue though
15:17	ToxicFrog	Now, my types are all completely hosed after a year of updates without bothering to typecheck anything, but I know how to fix that~
15:19	johnwalker	grep -v ann ?
15:25	ToxicFrog	Ok, new core.typed question!
15:26	ToxicFrog	I have a function that's basically (defn register-foo! [& xs] (def foo (into foo xs)))
15:26	ToxicFrog	I gave it signature [Any * -> Nothing]
15:27	ToxicFrog	But apparently it actually has signature [Any * -> (Var (Vec Any) (Vec Any))]
15:27	ToxicFrog	Which kind of makes sense if I read (Var old-type new-type) as being the type of def
15:27	ToxicFrog	Except Var doesn't exist in core.typed, so I can't use it as part of the signature!
15:31	amalloy	justin_smith: i just saw your comments on http://stackoverflow.com/questions/25793668/why-is-my-clojure-code-running-so-slowly. it's funny, i didn't actually intend for the powers-of-two sequence to be especially inefficient as part of the problem; i didn't really imagine anyone realizing a finite-but-too-large piece of it
15:31	justin_smith	heh, here i thought it was an excellent design choice in constructing the puzzle :)
15:31	ToxicFrog	Hmm, ok, it actually wants either (Var1 T) or (Var2 Tw Tr) even though the error message reports it on Var
15:32	amalloy	sometimes i did create intentionally-large inputs so that you'd have to think about performance, but most of the time i just wanted any correct solution to work
15:33	amalloy	it's an interesting problem. looking back at it now i'm not even sure if the solution i wrote years ago is actually efficient or not: https://www.refheap.com/90119
15:34	amalloy	it seems inefficient because it goes over every seq but the first multiple times, but...can you do better? i don't know that you can
15:37	justin_smith	amalloy: https://www.refheap.com/90120 mine, does a bunch of sorting, so is likely slower
15:37	amalloy	certainly my in-lists? is a bad reimplementation of every?
15:37	ToxicFrog	Seriously tempted to just :refer :all when I use core.typed now, remembering which things need t/ and which don't is a pain
15:38	amalloy	justin_smith: well, there are certainly inputs for which yours is faster
15:39	amalloy	well, maybe not. i dunno. performance is hard
15:39	justin_smith	benching them now
15:40	justin_smith	use criterium, it's a library, it's a space heater, it solves random clojure trivia
15:43	amalloy	justin_smith: i was going to suggest using test.check to generate evil input sequences, but...since it just has to be N sorted collections, there's really nothing exciting it could do
15:45	justin_smith	as long as the solution is smart enough not to be over eager in reading any inputs
15:45	justin_smith	and that final test is good on that count
15:46	justin_smith	https://www.refheap.com/90122 looks like mine was significantly faster (> ms µs ns)
15:47	justin_smith	I dunno - is it worth benchmarking again predefining the functions?
15:47	justin_smith	may as well
15:48	amalloy	justin_smith: don't predefine them, just let them outside: (letfn [...] (bench ...))
15:48	amalloy	but no, i don't think it matters at all
15:52	amalloy	justin_smith: you can improve yours quite a bit, actually, by not sorting and by possibly advancing multiple inputs at once: https://www.refheap.com/0142f12d90d7cef1ac56a0222
15:53	dbasch	justin_smith: here's mine fwiw https://www.refheap.com/90124
15:54	dbasch	which has obvious improvements
15:54	amalloy	dbasch: ah, using max is cute, although you can use drop-while instead of next, as in my recent suggestion
15:54	dorkmafia	how do you create a new instance of a java class from clojure? (ClassName. (arg1) (arg2)) ?
15:54	dbasch	(I mean can be improved obviously)
15:54	amalloy	and, just for style points: (let [[mi ma] (apply (juxt min max) ...)] ...)
15:54	justin_smith	dbasch: interesting
15:54	dbasch	amalloy: that's what I meant, I look at it now and I could have done it less redundantly
15:55	tadni_	So, I'm glad to see that "Clojure From The Ground Up" should be more or less done by Janurary.
15:55	dbasch	juxt wasn't on my radar at that point
15:55	amalloy	yeah, (apply (juxt min max) ...) is a trick that still confuses me
15:55	amalloy	like, i know it works, but my head hurts if i think it through
15:57	amalloy	i love that these 4clojure problems are still interesting years later, knowing much more about the language
15:57	justin_smith	yeah, it's pretty cool
15:59	justin_smith	amalloy: dbasch: I wouldn't have guessed so, but mine is still fastest - though dbasch's version is close https://www.refheap.com/90125
16:00	amalloy	justin_smith: it'll depend on the inputs for sure
16:00	justin_smith	yeah, just using the "tricky" input
16:00	justin_smith	dbash's would excell with a longer input list
16:00	amalloy	and either yours or dbasch's would be improved by using drop-while instead of rest
16:00	justin_smith	true that
16:02	Bronsa	bbloom: re: hours ago -- no I haven't :)
16:02	Bronsa	also I just learned that src/foo/bar/baz/ is the same as src/foo.bar.baz for the jvm. I'm kinda tempted to mkdir clojure.tools.analyzer
16:02	bbloom	Bronsa: heh, just for less work when cd-ing?
16:02	justin_smith	oh, wow, that's a weird thing
16:03	Bronsa	bbloom: I have to tab like 6 times to find the first clj file on my tools.* libraries
16:03	technomancy	I wonder if that's imlementation-specific
16:03	bbloom	Bronsa: i was super excited when github released the deep-jump links thingt
16:04	Bronsa	bbloom: me too!
16:04	technomancy	I remember reading some crazy thing about how dashes in class names are actually supported by openjdk, just not the JVM spec
16:04	Bronsa	bbloom: my actual comment on #clojure-offtopic "the first github UI change I approve"
16:04	joobus	how do I call Integer/parseInt from my code? I can call from the repl, but in my code I get a compile error.
16:04	justin_smith	bbloom: Bronsa: maybe we need deep-jump-find-file
16:04	Bronsa	technomancy: dunno, I actually saw this on the openjdk source tree
16:05	amalloy	justin_smith: ido-mode has a setting for that somewhere
16:05	technomancy	Bronsa: the five users of Clojure on IBM's JDK will yell at you
16:05	justin_smith	joobus: are you using it as if it were a first class function? it isn't one
16:06	joobus	justin_smith: I guess I am. (map Integer/parseInt blah)
16:06	justin_smith	#(Integer/parseInt %) is one
16:06	joobus	ok
16:06	justin_smith	joobus: this is all because clojure functions are objects, not methods on some object
16:06	joobus	I guess that makes sense. i searched and found parseInt is a static method of java.lang.Integer
16:07	joobus	just didn't know how to handle that
16:07	joobus	thanks justin
16:07	technomancy	I don't really get why Clojure doesn't auto-memfn or its static equivalent
16:07	justin_smith	yeah, the idea is that an arg to a clojure function can be an object or primitive, but it can't be a method, they are not first class
16:08	technomancy	are there ambiguous contexts in which it can't be determined?
16:08	justin_smith	technomancy: it would be another bit of magic, I support being skeptical of magic
16:09	Bronsa	technomancy: that would almost always require runtime reflection
16:09	technomancy	justin_smith: I don't see how it's magic. how else would you interpret (map .toString objs)?
16:09	Bronsa	technomancy: compare Object foo(Object); Object foo(Object, Object);
16:10	Bronsa	how could you statically determine which one you're using when compiling (map Class/foo ..) ?
16:10	bbloom	(doc memfn)
16:10	clojurebot	"([name & args]); Expands into code that creates a fn that expects to be passed an object and any args and calls the named instance method on the object passing the args. Use when you want to treat a Java method as a first-class fn. name may be type-hinted with the method receiver's type in order to avoid reflective calls."
16:10	bbloom	note that you have to provide type hints
16:10	technomancy	Bronsa: I don't mind runtime reflection
16:11	bbloom	technomancy: the problem isn't that it requires reflection, it's that the reflection doesn't occur until later
16:11	Bronsa	technomancy: I do
16:11	bbloom	i guess that the compiler would warn on reflection when auto-memfn-ing
16:11	Bronsa	bbloom: I don't understand the distinction you're trying to make
16:12	technomancy	there's lots of stuff like that in clojure already; it seems like the line is drawn at a somewhat arbitrary spot
16:12	bbloom	Bronsa: sorry, i didn't fully think that thougth out. i guess that's also true of fn too
16:12	bbloom	ignore me :-P
16:13	Bronsa	technomancy: for instance-methods it wouldn't even be a matter of only "it would require reflection" -- you wouldn't even know what arities are available
16:14	tadni_	justin_smith: Yeah, Clojure from the Ground up -- the more I looked into it, appears to be more an introduction to the lang more-so a general compsci introduction.
16:14	technomancy	yet memfn exists
16:14	Bronsa	what would it do? turn .foo into (fn ([x] (.foo x)) ([x y] (. x y)) ..)?
16:14	Bronsa	technomancy: you have to provide the argc to memfn, that's the point
16:14	joobus	w00t! I've solved 4 project euler problems in clojure. I'm feeling slightly less noobish...
16:14	amalloy	technomancy: well, memfn is for a specific, single arity
16:15	AeroNotix	I'm seeing a http-kit/get call being blocked (where it should always return a promise). Any ideas why that would be?
16:15	amalloy	you can expand into a million different arities, as Bronsa points out, but it's not super-clean
16:15	technomancy	Bronsa: you actually don't?
16:16	justin_smith	tadni_: did you mean disillusioned? or does it disenfranchise you from some right you would otherwise have?
16:16	joobus	justin_smith: lol
16:16	justin_smith	"this tutorial is opressing me"
16:16	johnny_mck	Greetings! I haz questions if anyone cares to answer some? (mostly about programming in a functional style...)
16:16	dorkmafia	is this the correct syntax for creating a java class from clojure and passing constructor args (ClassName. (arg1) (arg2)) ?
16:16	amalloy	technomancy: yes you do. (memfn add) only accepts exactly one argument; (memfn add x) accepts exactly two...
16:17	tadni_	justin_smith: Well, if I were to follow the thinking in the "who is this guide for" and I was non-cis, or non-white and was using another guide ... then maybe. :^P
16:17	technomancy	huh... I've never used the second arity of memfn
16:17	tadni_	I'm saying, it's not really a general compsci text as much as a general introduction to clojure.
16:17	Bronsa	technomancy: you've only used on no-arg methods then :)
16:17	justin_smith	tadni_: true
16:18	justin_smith	johnny_mck: we grant permission to ask questions freely
16:18	joobus	johnny_mck: you should just ask and see if someone responds. that's what the pro noobs like myself do.
16:18	amalloy	justin_smith: unless it's about the new iphone
16:18	justin_smith	heh
16:18	justin_smith	yeah, maybe I should have qualified that
16:24	TEttinger	dorkmafia: ##(java.util.HashMap. 64)
16:24	lazybot	⇒ #<HashMap {}>
16:24	TEttinger	dorkmafia: ##(java.util.HashMap. (64))
16:24	lazybot	java.lang.ClassCastException: java.lang.Long cannot be cast to clojure.lang.IFn
16:25	TEttinger	64 is a constructor arg to that java class that is the initial capacity, IIRC
16:26	justin_smith	there's that javascript compiler that removes lines of code until everything compiles, we should do something similar with clojure, and removing parens
16:27	TEttinger	I think there could be some ambiguity.
16:27	TEttinger	,(map identity [+ 1 2 3])
16:27	clojurebot	(#<core$_PLUS_ clojure.core$_PLUS_@15773de> 1 2 3)
16:27	AeroNotix	I'm seeing a http-kit/get call being blocked (where it should always return a promise). Any ideas why that would be?
16:27	TEttinger	,(map identity [(+ 1 2 3)])
16:27	clojurebot	(6)
16:28	amalloy	justin_smith: the readme for wtfjs is sublime
16:29	justin_smith	indeed
16:50	defn	dnolen_: Whaddya know about probabilistic programming? I want to dig in and am curious if you have suggestions on papers, resources, etc.
16:50	dnolen_	defn: not much I just surveyed some literature at one point, Church is a good jumping off point
16:51	dnolen_	defn: http://projects.csail.mit.edu/church/wiki/Church
16:51	defn	dnolen_: Some fascinating stuff.
16:52	defn	Yeah I found the church lang. So many recent papers and research topics involved that I'm feeling overwhelmed.
16:52	defn	Probmods.org was a good intro, but I need to see more in practice. Anyway, thanks again.
16:53	defn	Oh, and mcmc has been done in clojure. If you're interested dnolen_
16:53	defn	https://github.com/farr/mcmc-clojure
16:53	dnolen_	defn: interesting though old and not maintained
16:54	defn	Yeah :/. Looks like I need to take a page out of the dnolen book and write clojure.core.prob
16:57	bbloom	defn: go for it!
16:58	jdkealy	Hello, I have been trying to use the AMI startup script for Dynamo DB and AWS. I have gotten the startup script to launch a new instance, but it stops and restarts itself with the following error: ./startup.sh: line 26: kill: (1768) - No such process, /dev/fd/11: line 1: /sbin/plymouthd: No such file or directory ... has anyone here encountered anything like this before ?
16:58	arrdem	defn: there's an implementation of distributions kicking around somewhere from contrib that may be interesting material as well although that's more probability modeling than a probabalistic structure
16:58	defn	jdkealy: I believe there is a #datomic channel
16:58	jdkealy	sorry about that! I thought i was in #datomic :/
16:58	defn	Np
16:59	defn	arrdem: I'll have a look. I think I know the one you're referring to. Been a long while since I went through contrib
16:59	defn	Thanks!
17:00	arrdem	defn: there's an old implementation of a distribution monad. It doesn't make a whole lot of sense as a monad, but the distribution structure has served me well in a tabletop game project.
17:08	dbasch	arrdem: wow, it hasn't been touched for 5 years https://github.com/richhickey/clojure-contrib/tree/master/src/main/clojure/clojure/contrib/probabilities
17:08	arrdem	dbasch: yep
17:08	arrdem	dbasch: oh do you still have that clojure vs clojurescript link?
17:09	dbasch	arrdem: this? https://github.com/clojure/clojurescript/wiki/Differences-from-Clojure
17:10	arrdem	dbasch: I found that... I seem to recall you mentioning some post about expressions that didn't behave the same.
17:13	dbasch	trying to find it
17:14	sdegutis	Quick, what's a good name for an app that does your chores for you?
17:14	andyf_	sdegutis: littleBrother ?
17:15	dbasch	sdegutis: siri :P
17:15	sdegutis	Something that won't invoke trademark infringement? :P
17:15	justin_smith	sdegutis: apprentice
17:15	justin_smith	it even has app in the name
17:17	sdegutis	Thanks everyone!
17:17	noonian	man, i'm going to be pondering that all day now
17:21	sdegutis	Oh maybe old maid? Or steward?
17:21	sdegutis	s/old//
17:23	noonian	i was thinking robo-maid or something
17:23	noonian	or no-chore no-more-chore
17:23	sdegutis	:D
17:23	sdegutis	Certainly not Golem.
17:24	technomancy	yeah, you wouldn't want folks thinking it was written in google go
17:24	sdegutis	Or that it's from LotR.
17:24	AeroNotix	I'm seeing a http-kit/get call being blocked (where it should always return a promise). Any ideas why that would be?
17:24	justin_smith	GoLem: a generator of high concept sci fi, written in google go
17:25	sdegutis	technomancy: I wrote an 80-line script in Go the other day, which downloaded some .tar.gz archives from the net, extracted them in-memory, and output contents of files matching a pattern.
17:25	cbp	sounds like a clojure 5 liner
17:25	sdegutis	technomancy: A few hours later, I replaced it with a 4-line Bash script.
17:25	technomancy	nice
17:25	sdegutis	I have never found a good use for Go that I haven't rewritten in something better.
17:26	ieure	Go is great if you enjoy writing "if (err != nil)" every other line.
17:26	sdegutis	:)
17:27	ieure	As someone who needs to write extremely correct software, Go sends me screaming.
17:27	technomancy	hey, when I was in school, you didn't have to get 100% on every test
17:27	technomancy	even if you got just like 90% it was no big deal
17:28	mdrogalis	Gonna put that on my resume. "I write sorta good code. Good enough anyways"
17:28	ieure	Hah.
17:28	mdrogalis	ieure: What industry do you work in?
17:28	sdegutis	<3
17:28	ieure	mdrogalis, Banking.
17:28	sdegutis	I was gonna guess "financial"
17:28	mdrogalis	Unit testing on your own bank account. Don't mess up too much, now.
17:28	AeroNotix	ieure: so what language do you use then?
17:29	justin_smith	mdrogalis: nah, you just add a test fixture that resets the balance :P
17:29	ieure	AeroNotix, Depends. We're a JVM shop, but write Java, Scala, Clojure, and JRuby.
17:29	sdegutis	<3 Java
17:29	ieure	Depending on what the thing is.
17:29	AeroNotix	ieure: and you think you can write more correct programs in Java than in Go?
17:29	sdegutis	Such nice. So language.
17:29	TEttinger	JRuby seems like the thing to not use for correctness
17:29	AeroNotix	sdegutis: are you kidding?
17:30	sdegutis	Who doesn't love Java?
17:30	sdegutis	(Besides hipsters.)
17:30	mdrogalis	justin_smith: "Gave myself some padding by adding a few zeros this week."
17:30	ieure	AeroNotix, I believe it is easier to write correct programs in Java than Go.
17:30	technomancy	Java: at least it has exceptions
17:30	AeroNotix	ieure: could it be that you're just more familiar with it?
17:30	ieure	AeroNotix, No.
17:30	AeroNotix	oh ok. Case closed.
17:30	mdrogalis	Hahah.
17:31	sdegutis	At the end of the day, there's nothing really wrong with Java, it's perfectly suitable for writing any kind of serious app in. Clojure is just the icing on the cake.
17:31	TEttinger	sdegutis, designed for average coders, by average coders?
17:31	TEttinger	Oak, anyway
17:31	AeroNotix	sdegutis: that's not a very nuanced opinion.
17:32	arrdem	TEttinger: read the CVs of the Java language committee and lets hear you say that again
17:32	TEttinger	I was kidding
17:32	sdegutis	AeroNotix: uhh
17:32	sdegutis	TEttinger: uhh
17:32	mdrogalis	Not sure how you can appreciate Clojure without realizing what's wrong with Java. D:
17:32	TEttinger	I know they got some very experienced devs on that team
17:33	TEttinger	and it is interesting how Java got by with less serious design flaws at an early stage than most other large languages
17:33	TimMc	Pity about the type system, though.
17:33	TEttinger	they had to do a big rewrite for generics, and they still aren't great
17:33	sdegutis	mdrogalis: There are quirks in every language, and that's kind of why I have a job actually, because writing software is kind of hard.
17:33	ieure	Java Generics are really terrible.
17:33	ieure	Is typed Clojure usable yet?
17:34	ieure	It seems very promising.
17:34	sdegutis	I could try and write Haskell all day but the tools I use now work fine.
17:34	TEttinger	I have wondered the same, ieure. it seems to be, though I haven't tried it.
17:35	ieure	I've been appreciating static typechecking more since I started writing systems that have to correctly deal with millions of dollars of other peoples' money.
17:35	TEttinger	the main thing I use clojure for right now is one-liners of very dense code.
17:35	TEttinger	##(clojure.string/join" "(repeatedly 2000(fn [](apply str(concat[(rand-nth ["rh""s""z""t""k""ch""n""th""m""p""b""l""g""phth"])](take(+ 2(* 2(rand-int 2)))(interleave(repeatedly #(rand-nth ["a""a""o""e""i""o""au""oi""ou""eo"]))(repeatedly #(rand-nth ["s""p""t""ch""n""m""b""g""st""rst""rt""sp""rk""f""x""sh""ng"]))))[(rand-nth ["os""is""us""um""eum""ium""iam""us""um""es""anes""eros""or""ophon""on""otron"])])))))
17:35	lazybot	⇒ "rhauchaumor peobus rhamor pourkoistum teongeochium phthongoushor theonarstis zeofor phthaungeorstotron girtoirtanes pospeoshiam chepum toumon loitocheros zixophon lamon sabousotron gespium toxortis soirtenor laspum chomum paurteopis zeofepus moigum thortousheum togo... https://www.refheap.com/90131
17:35	justin_smith	ieure: there is also prismatic/schema
17:35	sdegutis	In fact, I'm betting on the fact that people are overly picky about languages, and I'm embedding 4 different scripting languages into my upcoming commercial app.
17:36	dbasch	TEttinger: future you would like to have a word with present you
17:36	sdegutis	They can choose between Ruby, Java, Python, or Lua.
17:36	ieure	justin_smith, Looks interesting.
17:36	arrdem	dbasch: lol
17:36	sdegutis	er, JavaScript
17:36	TEttinger	dbasch: the reduced need for spaces helps with these one-liners fitting in 400 or so characters
17:37	amalloy	and imagine the savings on commas
17:38	dbasch	amalloy: I like my machine code to have more ones than zeros because it saves ink when printing them out in binary
17:40	TEttinger	I'm currently almost exclusively writing C# for a rapidly-expanding-in-code-size renderer for voxel models. I'm hoping to use the rendered stuff from clojure using play-clj when I get closer to done.
17:43	dbasch	arrdem: I found this in my browser history, it only goes back 90 days https://gist.github.com/alandipert/2346460
17:44	arrdem	dbasch: thanks for looking
17:51	sdegutis	lol, Proletarian
17:59	TEttinger	,(filter #".foo." ["foobar" "goobar" "foobaz"])
17:59	clojurebot	#<ClassCastException java.lang.ClassCastException: java.util.regex.Pattern cannot be cast to clojure.lang.IFn>
17:59	TEttinger	hm, I guess it doesn't work in vanilla clojure without further black magick
18:00	llasram	TEttinger: yeah -- in JVM Clojure there's no way to turn existing classes (like regular expressions) into IFns
18:00	technomancy	you could define a clojure.lang.Regex
18:01	TEttinger	you could add a reader literal to create your own REFn
18:01	technomancy	since no one has ever used #"" regexes for interop ever
18:01	TEttinger	it could also be a subclass of the java regexp
18:02	technomancy	llasram: no seriously
18:02	technomancy	I would be mildly surprised if anyone on this channel has ever done it
18:02	Bronsa	TEttinger except Pattern is final :)
18:02	TEttinger	wat
18:02	Bronsa	http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html
18:03	TEttinger	then you could have another class that has a Pattern as a member and itself implements IFn
18:03	technomancy	TEttinger: I would vote for that =)
18:04	Bronsa	TEttinger you couldn't use that for interop then
18:04	noonian	why do you need it to work with just a literal?
18:04	llasram	If classes aren't explicitly designed to be extensible, best to make them final. Keeps things all neat and tidy.
18:04	llasram	Prevents the proletariat from getting uppity etc
18:04	TEttinger	right, but you could get the Pattern out of it once and use that for interop
18:04	TEttinger	I dunno
18:05	Bronsa	TEttinger but there'd be no way to always known statically when you're passing a MyPattern instead of a proper Pattern to "unbox" it
18:06	TEttinger	I guess. the best solution would be to not interop, I suppose
18:06	Bronsa	you'd need to add instance checks + "unbox" paths everywhere you call a method taking a Pattern
18:06	Bronsa	which might not be too bad actually
18:06	technomancy	noonian: filtering on a regex is many orders of magnitude more useful than interopping a regex, so it's unfortunate that the latter is convenient and the former is not
18:09	Bronsa	I might actually attempt a patch for that one of the next days
18:10	Bronsa	it might break code that explicitely tests for j.u.regex.Pattern though
18:12	dorkmafia	http://paste.debian.net/120473/ why does line 17 throw a java.lang.NullPointerException the first time i call it but after that it's fine?
18:14	noonian	,(filter (partial re-find #".foo.") ["foobar" "goobar" "foobaz"])
18:14	clojurebot	("foobar" "foobaz")
18:14	noonian	i'm happy enough with that though
18:16	dbasch	noonian: I'd probably want re-matches behavior rather than re-find
18:18	noonian	dbasch: it wouldn't matter for filtering though right? both would return a truthy value if there are any matches or nil otherwise if i'm not mistaken
18:18	dbasch	noonian: it depends on the regexp
18:19	noonian	dbasch: ah, good call
18:19	noonian	,(filter (partial re-matches #".*foo") ["foobarfoobar" "goobar" "foobaz"])
18:19	clojurebot	()
18:19	noonian	(filter (partial re-find #".*foo") ["foobarfoobar" "goobar" "foobaz"])
18:19	noonian	,(filter (partial re-find #".*foo") ["foobarfoobar" "goobar" "foobaz"])
18:19	clojurebot	("foobarfoobar" "foobaz")
18:22	dorkmafia	is there something wrong I'm doing with the chaining of functions?
18:24	dbasch	dorkmafia: what parameters are you calling that with? What's the exception?
18:26	dorkmafia	dbasch: http://paste.debian.net/120474/
18:29	dbasch	I don't see any calls there, just definitions
18:30	dorkmafia	it's in the handler
18:32	noonian	so where do you create the handler? it looks like all those functions get it passed in
18:32	dorkmafia	http://paste.debian.net/120475/
18:33	dorkmafia	hmm
18:33	dorkmafia	maybe it's passing nil as the from-user?
18:34	noonian	yeah maybe, you might get a message where the body isn't blank but there is no :from-name
18:35	noonian	i'd definitely print the message for now so you know what it's getting
18:38	dorkmafia	hmm
18:38	dorkmafia	k
18:41	dorkmafia	nope the from-user is correct
18:42	dorkmafia	it doesn't print out twice which is strange
18:55	dorkmafia	noonian: i think it has to do with the roster not being defined
18:57	dorkmafia	(defn roster [conn] (when conn (.getRoster conn) )) am i using when correctly here?
18:59	dbasch	dorkmafia: it depends on what you want. If conn is falsey that will evaluate to nil.
19:02	dorkmafia	hm i dunno
19:03	noonian	dorkmafia: i'd change it to an if for now and print something if the conn is nil
19:03	noonian	its nice to have more information during dev/debugging
19:06	dorkmafia	(.getEntry (roster conn) uname) )
19:06	dorkmafia	could it be due to taht?
19:06	dorkmafia	i'm going to try and use a local variable for the roster there
19:07	technomancy	IMO you should check for nils as early as possible and error out
19:07	technomancy	letting them leak through any old place in your program makes for bugs that are tedious to track down
19:08	dorkmafia	all of the inputs are fine
19:13	dorkmafia	is it possible I need to set java types for the return types of some of these methods?
19:14	amalloy	dorkmafia: no
19:15	tuft	technomancy: they can work like a poor man's maybe monad, which is nice
19:16	technomancy	monads without a type checker... poor man indeed =)
19:23	dbasch	dorkmafia: I still don't know how you're starting the whole thing. I assume you call starter-bot, but what is smack/start-bot?
19:23	amalloy	sounds like bot abuse to me
19:24	dbasch	amalloy: you just reminded me of a Futurama episode
19:26	dorkmafia	dbasch: there is another class i missed lol sorry
19:27	dorkmafia	http://paste.debian.net/120478/
19:36	dbasch	dorkmafia: that code is pretty convoluted, where does it come from?
19:36	dorkmafia	yah that's why i'm trying to make it better it's from xmpp-clj
19:36	dorkmafia	on github
19:46	dorkmafia	dbasch: should i just start over? lol
19:48	adereth	I wish I had done the Heroku Clojure walkthrough sooner. That was really easy.
19:48	adereth	Made a toy: http://templar-clj.herokuapp.com/
19:48	adereth	http://templar-clj.herokuapp.com/?url=http%3A%2F%2Ftemplar-clj.herokuapp.com%2F
19:55	justin_smith	adereth: is it giving a templated version of the page provided?
19:55	locks	cute
19:56	justin_smith	An error occurred in the application and your page could not be served. Please try again in a few moments. If you are the application owner, check your logs for details.
19:58	adereth	Yes
19:58	adereth	In Enlive, Hiccup, and Hickory style
19:58	adereth	Oh noes. Still?
21:12	yedi	jsut to confirm, clojure lists have 0(1) prepending and appending correct?
21:12	bbloom	yedi: prepending only
21:13	yedi	oh... that's unfortunate. is there a data structure that also keeps a pointer to the end of the lis tas well
21:13	bbloom	yedi: concat constructs a lazy sequence in O(1) time
21:13	bbloom	yedi: vectors have fast push/pop from the tail and can be converted in to a seq in O(1) time
21:14	bbloom	if you genuinely need push/pop from both sides, there are contrib libs for finger trees and rrb vectors
21:14	justin_smith	yedi: there is a lib with a persistent deque (which does fast prepand and append)
21:14	bbloom	but it's pretty rare that you actually need that
21:14	yedi	justin_smith: ah i think that was the library you linked me to before
21:14	justin_smith	yedi: probably
21:14	yedi	bbloom: well i'm creating a queue that needs to be able to append on one side and pop from the other
21:15	justin_smith	but you wanted a queue actually, right? and there is a built in Persistentqueue if you want fast front insertion and fast tail removal
21:15	bbloom	,clojure.lang.PersistentQueue/EMPTY
21:15	clojurebot	#<PersistentQueue clojure.lang.PersistentQueue@1>
21:15	yedi	this is on clojurescript btw
21:15	TimMc	"by the way"
21:15	yedi	>_<
21:15	bbloom	yedi: i think cljs has persistent queue also...
21:15	yedi	sweet, ill go check
21:17	TimMc	I'd be curious to hear what you find.
21:17	bbloom	it's there
21:18	yedi	yep
21:48	zeebrah	adereth: is there a link to the walk through?
21:52	truebuddi	any tips or good reading links about how an experienced OO dev can think of modeling data in a functional world?
21:53	rubygeek	maybe this? https://leanpub.com/fp-oo
21:53	matthoffman	truebuddi: I quite liked that one
21:54	justin_smith	truebuddi: many of Rich Hickey's video talks are about contrasting Clojure style functional programming to Java style OO
21:55	truebuddi	I did a lot of reading .. practiced almost everything from iloveponies.github.com; watched quite a few talks from rich hickey .. recently started looking at joy of clojure .. i get the language but am having trouble getting something real done in clojure ...
21:56	justin_smith	truebuddi: what real things have you tried to do?
21:57	truebuddi	justin_smith: well i wanted to build a small web app .. for fun kind ..but have some starting trouble ...
21:58	justin_smith	what were your roadblocks?
21:58	matthoffman	it can be tough to stare at a blank page and think of how to model the world functionally when you're used to OO; i found it easier to try adding a feature to an existing project.
21:58	matthoffman	'cause then i had to walk through existing code and figure out how they modelled things
21:59	jasonjck_	following SICP in clojure is a good way to learn
22:00	jasonjckn	i think there's a whole clojure book on webapps
22:00	jasonjckn	it's not joy of clojure
22:00	justin_smith	truebuddi: anyway, if you have specific questions, feel free, all of my largest clojure projects have been either web apps or my work on a web app framework, and I know a number of other folks here do clojure web apps too
22:00	truebuddi	@justin ... for eg, i want to build a "trip journal" where you have a "group of people". each person can comment on a trip...trip cannot be deleted by anyone else other than that person who created it ... things like that ...
22:01	bja	where has prismatic/schema been all of my life?
22:02	justin_smith	truebuddi: on a data modeling level, a database is by definition not functional (unless you use something like datomic that has an immutible history, but frankly I think that is often overkill) - functional programming can use persistence and mutation judiciously, just as OO can use immutible data or static methods
22:02	justin_smith	bja: I know, right?
22:03	justin_smith	truebuddi: the key, for me, is to have a clear mental model of where and why the mutation / persistence occur (they often go hand in hand), and how they integrate with the purely functional ecosystem that is the rest of my code
22:03	bja	built a coercer to handle configs pulled in via environ/zookeeper
22:03	bja	my life is now simple
22:04	justin_smith	bja: as long as you don't expect to be able to use watches, or treat it like a db, zookeeper is awesome
22:05	truebuddi	justin_smith: initially i am not even worried about persistence ... for the most part I am only concerned about how you would you model something? say I want anemic object Person .. with a name, profile picture, some description ... you make the person a map or a record or what...thats the kind of stuff that isn't clear to me yet
22:05	justin_smith	truebuddi: to be more concrete, I will usually associate a request with gathering db data coming in, and then writing db data on the way out again
22:06	justin_smith	truebuddi: use a map until maps are a bottleneck
22:06	justin_smith	truebuddi: use assertions or prismatic/schema to make sure the data has the shape you expect
22:06	bja	justin_smith: what's wrong with using watches?
22:06	justin_smith	bja: they are flawed inside zookeeper
22:07	justin_smith	bja: oh, I mean avout - the clj zookeeper binding that acts like an atom
22:07	justin_smith	it makes zookeeper extremely easy to use, but the watches are not worth it (and don't use it for large data sizes)
22:07	bja	I've been using watches for settings updates
22:08	bja	but have not been using about
22:08	justin_smith	bja: I specifically meant watches on avout/atom objects
22:08	bja	ah, ok
22:08	justin_smith	bja: http://avout.io/ check out the example code - they do make it very similar to clojure.core atoms
22:09	justin_smith	(and refs also, but there is less reason to use those)
22:09	bja	oh, I saw that on /r/clojure I think
22:10	justin_smith	but I am sure zookeeper is awesome on its own too (and in some ways simpler when it doesn't try to pretend to be a standard clojure reference type)
22:10	bja	yeah. We're just using it to distribute settings
22:11	justin_smith	right, that is what I did too, but being able to look at the settings like atoms was a bonus
22:11	bja	having a config schema makes it easy to know that a bad settings push won't blow up my production systems
22:14	justin_smith	truebuddi: another revelation for me was focusing less on creating structures that emulate the real world and more on creating stateless transformations that can be composed to create the process I need
22:15	justin_smith	truebuddi: if my map needs a new key in it, or the list needs to become a vector, this is a simple change if I wrote my code well - the interesting part isn't getting the data model perfect up front, its being able to quickly iterate the data transformations until I have the program I need
22:17	truebuddi	justin_smith: so you suggest I start with something basic ... just model as much data as I could with what I know ... maps...lists ... vectors..sets and then refactor later?
22:17	justin_smith	truebuddi: yeah, that is how clojure programs typically evolve
22:17	justin_smith	and all the operations on maps are supported on records
22:17	justin_smith	so if you need something more specific later, you can upgrade easily
22:18	truebuddi	justin_smith: now that makes me worry next about ownership ... usually in OO you can have a repository which owns a list of people .. so in a fp world who owns say a list of my persons? another structure eventually in a global context?
22:19	justin_smith	truebuddi: maybe you've seen that Alan Perlis quote? It is better to have 100 functions operate on one data structure than 10 functions on 10 data structures."
22:19	justin_smith	truebuddi: when you have ubiquitous immutibility, ownership becomes less important - when you need mutation, keep it near the owner, and export something immutible at the earliest practical moment
22:19	truebuddi	justin_smith: I didn't know it was from Alan Perlis but heard of that quote when doing some reading about Clojure and Rich Hickey quoted it somewhere i guess ..
22:21	ToxicFrog	How do I express "this function does not return" in a core.typed annotation?
22:22	justin_smith	truebuddi: so, since you need a mutible storage of user data (assuming that is what "people" are for here), I would make a people ns, keep all implementation details internal to that ns, and clearly delineate the functions comprising the API, which returns immutible people for queries, or takes update maps and manages state based on those updates
22:23	TimMc	ToxicFrog: Declare it to yield _\|_, obviously. :-P
22:23	truebuddi	justin_smith: so use ns to organize functionality .. hmmm
22:24	justin_smith	truebuddi: yeah, for me an ns represents some group of related abilities provided to other code
22:24	TimMc	ToxicFrog: (No, I don't actually know if core.typed supports bottom.)
22:25	truebuddi	justin_smith: what do you think of https://leanpub.com/fp-oo that was suggested earlier to me ..
22:25	justin_smith	⏟⏟ <- a much more shapely bottom, thanks to unicode
22:25	ToxicFrog	TimMc: it describes "Nothing" as "the bottom type"
22:25	justin_smith	truebuddi: I have not read it
22:25	TimMc	justin_smith: Oh, Unicode and its shapely bottoms...
22:26	truebuddi	justin_smith: been a few years since I did web dev ... anyway do you have a suggestion for a small but practical web app that I can study preferably one in clojure/cljs
22:26	TimMc	ToxicFrog: But then the docs say "Nothing is the bottom type that inhabits no types except itself." which I think disagrees with (say) the Haskell notion of bottom.
22:26	TimMc	_\|_ is supposed to inhabit all types, right?
22:27	truebuddi	justin_smith: I played around with compojure, http-kit .. so i am not too concerned about the technology but am more interested in how things like sessions, cookies, web sockets are mixed with business end of things in clojure
22:28	justin_smith	truebuddi: https://github.com/prismofeverything/schmetterling is by a friend of mine (I contributed extensively to the design, but less to the actual code) - sadly I can't think of a really good web service in clojure for reading off the top of my head (all my good ones are closed source client work)
22:28	justin_smith	TimMc: stupid sexy unicode
22:31	TimMc	justin_smith: http://www.boardsandrec.com/showthread.php?t=82114
22:31	TimMc	"unicode butt" is now in my google search history, forever
22:32	justin_smith	lol
22:34	justin_smith	and all along, I was looking for: ⊥ "UP TACK"
22:34	justin_smith	why the hell is it called up tack? who knows
22:35	TimMc	*files, also
22:35	teslanick	Looks like a tack sitting on its head, pointing up?
22:35	justin_smith	right, but I have never heard it called that name in a mathematical context, though it is categorized as a mathematical symbol
22:36	justin_smith	TIL http://en.wikipedia.org/wiki/Up_tack
22:36	justin_smith	"falsum"
22:37	justin_smith	also, (⊥) has an antonym, (⊤) and both look kind of butt-like when parenthesized
22:38	teslanick	Indeed. It's like the two great taxinomies of highly convex rear-ends.
22:38	teslanick	I think Sir Mix-A-Lot wrote a ballad to the union of both taxonomies.
22:39	justin_smith	(inc teslanick)
22:39	lazybot	⇒ 2
22:39	teslanick	\o/ I will treasure this.
22:44	ToxicFrog	Man, apply+core.typed is my worst enemy
22:44	ToxicFrog	Target: (IFn [java.lang.String Any * -> java.lang.String])
22:44	ToxicFrog	Arguments: (clojure.lang.PersistentList String)
22:45	ToxicFrog	Those look type-compatible to me!
22:45	justin_smith	ToxicFrog: is apply worse than other higher order constructs?
22:45	ToxicFrog	justin_smith: well, it's the only one giving me grief
22:46	justin_smith	one of these days I will take the core.typed plunge - I think I'll try using prismatic/schema more extensively first though
22:46	ToxicFrog	An earlier issue with it was entirely my fault -- (apply f x ys) matches the type [X Y * -> ...], not [X (Vec Y) -> ...]
22:46	ToxicFrog	But here it looks like it should be type-compatible; the PersistentList String expands to String String String... when applied, so it should match the signature [String Any * -> ...]
22:48	ToxicFrog	I also get this new and exciting error:
22:48	ToxicFrog	Type Error (bltool/data/default.clj:26:1) Internal Error (bltool/data/default.clj:26:1) Unreachable method: Local inferred to be bottom when applying multimethod filter
22:50	ambrosebs	ToxicFrog: that will fail for an empty list
22:51	truebuddi	+cnt
22:51	ToxicFrog	ambrosebs: in this case, the list is generated by macro expansion and is known at compile time to be nonempty.
22:51	ToxicFrog	(and I don't control the macro, it's slingshot's throw+)
22:52	ambrosebs	ToxicFrog: very likely throw+ will need a typed variant.
22:52	ambrosebs	for any complicated macro it's usually the case
22:52	ToxicFrog	As in, write my own type-annotated replacement for it?
22:52	ambrosebs	yes
22:52	ToxicFrog	D:
22:52	ambrosebs	like clojure.core.typed/for is for clojure.core/for
22:53	ToxicFrog	I don't suppose there's some way I can tell it to just not check anything inside a throw+ block
22:53	ToxicFrog	(also, any idea on the internal error?)
22:54	ambrosebs	ToxicFrog: hmm I'd need to see the defmulti/defmethod
22:55	ambrosebs	ToxicFrog: core.typed just macroexpands out everything blindly and checks it
22:55	ambrosebs	the solution is another macro unfortunately
22:59	ToxicFrog	ambrosebs: they're pretty simple: https://gist.github.com/ToxicFrog/73e20b453e4b578ab590
22:59	ToxicFrog	And it's only the second one that it generates that error on, which is especially weird.
23:00	ambrosebs	ToxicFrog: the return type should not be Nothing
23:00	ambrosebs	Nothing means an error
23:00	ambrosebs	of write-games
23:01	ToxicFrog	What should it be, then? nil?
23:01	ToxicFrog	Also, that passes type checking, it's read-games that it objects to.
23:01	ambrosebs	oh right I see
23:02	ambrosebs	ToxicFrog: so it's saying that read-games with dispatch value "nil" is unreachable based on the type of the multimethod
23:03	ambrosebs	perhaps the first argument of read-games should be (U nil String)
23:04	ambrosebs	note that core.typed shouldn't really be complaining this loudly
23:04	ambrosebs	it should just ignore the method and move on
23:04	ambrosebs	but I decided to be noisy at least while core.typed's implementation is relatively young
23:04	ToxicFrog	Yep, if I changed it to (U nil String) it stops complaining about that one and starts complaining about the fourth one.
23:05	ambrosebs	right same issue I guess
23:05	ToxicFrog	Yeah.
23:05	ambrosebs	nothing to do with the Nothing return type
23:05	ToxicFrog	Either can be nil for "argument not specified"
23:05	ToxicFrog	And now all four of them are complaining about "bad arguments to apply" from throw+'s use of format, which is more in line with what I'd expect.
23:07	ToxicFrog	For now I think I'll just mark that ns :collect-only, I really only care about it for checking the other defmethods associated with it.
23:07	ambrosebs	good idea
23:10	ToxicFrog	...hmm. How do I mark it :collect-only? I can't find docs for this, and I thought it was just (ns bltool.data.default ^:collect-only ...) but that doesn't appear to do anything.
23:11	ToxicFrog	Oh, I see. It's either (ns foo {:core.typed {:collect-only true}} ...), or (ns ^{:core.typed ...} foo ...)