#clojure – 2014-09-01

2014-09-01

02:28	sm0ke	so if i am building this nested map {:a {:b {:c 1 :d x}}}, i want if x is nil its not assoc'd to the map
02:28	sm0ke	is there a nice way to do this
02:31	TEttinger	,(let [m {:a {:b {:c 1}}} x nil] (if (nil? x) m (update-in m [:a :b :d] x)))
02:31	clojurebot	{:a {:b {:c 1}}}
02:31	TEttinger	,(let [m {:a {:b {:c 1}}} x 2] (if (nil? x) m (update-in m [:a :b :d] x)))
02:31	clojurebot	#<ClassCastException java.lang.ClassCastException: java.lang.Long cannot be cast to clojure.lang.IFn>
02:31	TEttinger	,(let [m {:a {:b {:c 1}}} x 2] (if (nil? x) m (update-in m [:a :b :d] (constantly x))))
02:31	clojurebot	{:a {:b {:d 2, :c 1}}}
02:31	sm0ke	yes thats the obvious way, i was looking something `easy`
02:32	TEttinger	well I imagine it wouldn't be hard to make that into a more general function. the update-in is the tricky bit
02:33	TEttinger	closest thing I can think of is when-let
02:33	TEttinger	(doc when-let)
02:33	clojurebot	"([bindings & body]); bindings => binding-form test When test is true, evaluates body with binding-form bound to the value of test"
02:33	sm0ke	yes yes, but i want this to work on arbitary data e.g.
02:33	sm0ke	{:a {:b {:c [1 2 x]}}}
02:33	sm0ke	i want to eliminate that x
02:34	TEttinger	complex nesting is not the kind of thing there's pre-written solutions for
02:34	TEttinger	update-in is as close as it gets
02:34	TEttinger	I could be wrong and amalloy swoops in with a half-of-one-liner
02:35	sm0ke	i think it is impossible
02:35	TEttinger	well you haven't really described what you want
02:35	sm0ke	what i want is something like compile time with consitions on runtime
02:35	sm0ke	condition*
02:36	TEttinger	do you want to be able to replace any instances of some variable, like 'x , with a value regardless of where it is?
02:37	sm0ke	i just want an prettier alternative to what you did, (let [m {:a {:b {:c 1}}} x 2] (if (nil? x) m (update-in m [:a :b :d] x)))
02:37	TEttinger	,(count "(if (nil? x) m (update-in m [:a :b :d] x))")
02:37	clojurebot	42
02:38	sm0ke	you are ignoring the let form
02:38	TEttinger	because that's just your predefined stuff
02:38	TEttinger	that's stuff you would pass in
02:38	TEttinger	,(def m {:a {:b {:c 1}}})
02:38	clojurebot	#'sandbox/m
02:39	sm0ke	what if there was something like {:a {:b {:c 1 **-x :d x}}}
02:39	TEttinger	,(def x 2)
02:39	clojurebot	#'sandbox/x
02:39	TEttinger	,(if (nil? x) m (update-in m [:a :b :d] x))
02:39	clojurebot	#<ClassCastException java.lang.ClassCastException: java.lang.Long cannot be cast to clojure.lang.IFn>
02:39	sm0ke	**- is magic condition which ignores depending on x
02:39	sm0ke	:P
02:39	TEttinger	,(if (nil? x) m (update-in m [:a :b :d] (constantly x)))
02:39	clojurebot	{:a {:b {:c 1, :d 2}}}
02:39	TEttinger	well uh your map has 5 items
02:40	sm0ke	yes **-x is a reader macro
02:40	TEttinger	ok, you could probably do that yes. reader macros are kinda discouraged...
02:40	TEttinger	I'm thinking of reader literals
02:40	TEttinger	which are not recommended in libraries
02:40	sm0ke	#only/if
02:41	sm0ke	i am not sure if even that would work
02:41	sm0ke	it is impossible to do this {:a {:b {:c 1 #only/if :d x}}}
02:41	TEttinger	it should be. hang on
02:42	TEttinger	,{:a {:b {:c 1 #_ :d #_ x}}}
02:42	clojurebot	{:a {:b {:c 1}}}
02:42	TEttinger	so you can already ignore forms, you just want to do it selectively
02:42	sm0ke	yes my first though was also using (comment)
02:43	TEttinger	which returns nil, for some reason...
02:43	sm0ke	,{:a {:b {:c 1 (if false [:d 2] (comment))}}}
02:43	clojurebot	#<RuntimeException java.lang.RuntimeException: Map literal must contain an even number of forms>
02:43	sm0ke	wow stupid
02:44	TEttinger	it's true though
02:44	TEttinger	that's a key, [:d 2]
02:44	sm0ke	but it has to be a compile time thing you see? but (if x..) is a runtime thing
02:45	sm0ke	cant be done!
02:47	TEttinger	yeah, I think because you're trying to do it inside the map {} literal
02:47	sm0ke	yes we would need a special macro for [] {} etc to do this
02:47	TEttinger	if is a macro, and I admit I'm not an expert on macros
02:48	sm0ke	ugh, i am going back to if's and let's
02:49	TEttinger	yes, if is what you should use here
02:49	TEttinger	all other solutions are much more hackish
02:52	sm0ke	so all that we need is this (runtime-to-compiletime-if x [:d 2]) this evaluates x during runtime and spats :d 2 (flattening them) for the compiler
02:52	sm0ke	which makes no sense
02:53	sm0ke	yay! I just wasted your 15 minutes
03:10	SagiCZ1	anyone remembers how do i access this channels logs?
03:11	beamso	http://logs.lazybot.org/irc.freenode.net/%23clojure/2014-09-01.txt
03:12	SagiCZ1	beamso: thank you
03:13	SagiCZ1	i need couple more hours back
04:53	JL235	Has anyone got any experience with clojure-clr?
04:53	JL235	I am thinking of using it
04:53	JL235	I have a .net project and thinking of rebuilding it with clojure (as I also want to get into Lisp too)
04:55	clgv	JL235: what is stopping you from trying it?
05:15	JL235	nothing
05:15	JL235	but I don't want to invest time moving a project over to something that may have a lot of warts
05:15	JL235	not when I could go with something else instead
05:15	JL235	so just asking around on people's experiences
05:18	clgv	JL235: well, before migrating a project you need to learn the language. Hence, I asked what is stopping you from trying out clojure and start learning the basics?
05:24	JL235	I am not asking in regards to learning the language
05:25	clgv	JL235: what are you asking then? the more specific the question the likelier you get a helpful answer
05:26	JL235	"Has anyone got any experience with clojure-clr?"
05:30	maxthoursie	JL235: I've tried to use it, but while core is there, lot's of libraries aren't. I ended up going with jvm clojure instead
05:37	jyfl987	hi can anyone give me some example showing parsing weblog file , the filename should be given by cmdline
05:40	riffraff	hi everyone
05:41	riffraff	I'm tryint to add test.check tests to my project and I'd like to have them run as normal tests as per clojure.test
05:41	riffraff	AFAIU I shoiuld use defspec, but I get a Unable to resolve symbol: defspec in this context
05:42	riffraff	any ideas of what I'm doing wrong? Sorry if' it's a silly question, I'm a newbie :/
05:44	JL235	thanks maxthoursie
05:44	riffraff	ah I found it in another namespace maybe
06:13	clgv	riffraff: why not deftest?
06:13	riffraff	it was my understanding defspec was the preferred way to use test.check with clojure.test
06:13	clgv	riffraff: ah defspec is part of test.check
06:13	riffraff	yeah
06:13	riffraff	the name is somewhat confusing to me as it seems to refer to some BDD framework
06:13	clgv	from the tests in test. heck it seems to be the way to go
06:13	riffraff	yes I got it working now
06:13	riffraff	the trick was that it's defined in clojure.test.check.clojure-test
06:13	clgv	for future readers, it is in clojure.test.check.clojure-test
06:13	riffraff	but this is not called out in the readme. As a noob I assumed I was doing something stupid with requires :)
06:13	clgv	yeah, there could be more documentation.
06:13	clgv	I am just fiddeling with recursive generators
06:16	riffraff	err, another silly question: given "lein repl" where my project.clj has org.clojure/test.check in the dependencies, should (require '[clojure.test.check :as tc])
06:16	riffraff	work ?
06:20	clgv	riffraff: yes, it should
06:20	clgv	riffraff: do you do any profile magic?
06:20	riffraff	not that I am aware of
06:21	clgv	did you restart the repl after adding the dependency?
06:23	riffraff	the one I just opend yes
06:23	riffraff	not sure if there is some daemin process I need to restart too
06:24	clgv	riffraff: no. requiring should work then
06:25	clgv	replace "should" with "must"
06:26	riffraff	eh :)
06:29	riffraff	ah I think it _is working, but I was looking at it wrongly
06:30	riffraff	basically, trying to see if the symbol "tc" was bound to something (by typing "tc" in the repl)
06:30	riffraff	but it's not, while tc/quick-check instead is
06:30	riffraff	I think I need to study this namespacing thing a bit more
06:30	riffraff	thanks anyway
06:51	clgv	riffraff: ah ok.
06:52	clgv	,(require '[clojure.string :as str])
06:52	clojurebot	nil
06:52	clgv	,(keys (ns-aliases ns))
06:52	clojurebot	(str)
06:52	clgv	riffraff: that's a way to check the alias ^^
06:52	riffraff	awesome, thanks
06:53	clgv	,((ns-aliases ns) 'str)
06:53	clojurebot	#<Namespace clojure.string>
06:53	clgv	^^ to see where it maps to
06:56	martinklepsch	when evaling (println "something") in cider, is there a buffer where I can see the result?
06:56	martinklepsch	ah, nevermind
06:56	martinklepsch	the cider-repl buffer :)
07:30	SagiCZ1	if i have a non-atom list of atoms can i see their changes?
07:34	clgv	SagiCZ1: example?
07:35	SagiCZ1	(def a (atom 0)), (def b (atom 1)), (def v [a b]), .. now i keep the reference to "v" i can swap! the atoms in it right?
07:37	noidi	yes, but not atomically :)
07:37	SagiCZ1	noidi: elaborate?
07:38	clgv	SagiCZ1: you cant guarantee any consistence between the two atoms
07:39	clgv	SagiCZ1: your options are to have the vector within an atom or to use references instead of the atoms
07:39	noidi	SagiCZ1, say both atoms start at 0 and you want to `inc` them. an observer may observe a world in which one atom has the value 1 and the other 0
07:39	clgv	SagiCZ1: btw your usage of def for `a` and `b` is alarming
07:46	SagiCZ1	why is alarming?
07:53	SagiCZ1	(ns my-ns (:require [ui]))
07:53	SagiCZ1	this says it could not locate ui__init.class but i have the ui namespace in the same folder, whats wrong?
07:56	llasram	SagiCZ1: namespaces are always absolute, never relative
07:57	SagiCZ1	thank you, it works now
07:58	clgv	SagiCZ1: because `def` is only intended for global variables
07:59	SagiCZ1	clgv: these are supposed to hold game's state and i read that game state should be global and immutable
08:00	lq	ls
08:00	lazybot	bin etc home lib lost+found media mnt opt proc root sbin sys usr var
08:01	llasram	SagiCZ1: Yeah, but you don't need two top-level references to the same object. E.g., just: (def game-state [(atom 0) (atom 0)])
08:01	llasram	(or whatever)
08:02	SagiCZ1	oh yes ive already changed that.. it was just for the example.. thank you though
08:02	clgv	SagiCZ1: what llasram said ^^
08:04	clgv	SagiCZ1: I think the decision between game state as global variable or game state as function argument is not that clear as you state
08:04	SagiCZ1	clgv: its the only that makes sense to me.. i cant wrap my head around passing game state around 20 functions
08:05	llasram	SagiCZ1: And yet it has a lot of benefits
08:05	clgv	SagiCZ1: that way you are tempted to have no pure functions at all
08:06	SagiCZ1	if i try to use only pure functions i cant progress at all.. do you have any examples of very simple games with pure functions?
08:06	clgv	SagiCZ1: pure functions are "easy" to test
08:06	llasram	At my company we started off with several things that it seemed to "make sense" would just be global state, like configuration
08:07	llasram	And we've realized it was pretty much all a terrible idea, which has made code much harder to test, and are moving to pure-as-possible functions for everything
08:07	SagiCZ1	llasram: i understand all the advantages of pure functions.. which does not make me able to write them
08:07	clgv	SagiCZ1: well, you will have at least one function that holds the atom, e.g. the main game loop
08:07	llasram	SagiCZ1: Why is it harder? You just have an extra first argument to your functions which is the game state
08:08	lvh_	is there a codecs library I'm missing? I need urlsafe base64; the only one I can find is inside buddy
08:08	lvh_	and dragging in all of buddy for 10 lines or so seems silly
08:08	llasram	lvh_: Apache Commons?
08:08	lvh_	(as does copying those 10 lines)
08:08	lvh	llasram: does that have urlsafe base64? I thought it didn't, I'll double check
08:08	llasram	Oh, maybe not. I just assumed it would
08:08	clgv	lvh_: isn't there some clojurewerkz lib for URLs that is able to do that?
08:08	llasram	What makes normal base64 not URL-safe?
08:09	lvh	llasram: wait, you're right, it does :)
08:09	llasram	cool
08:09	lvh	clgv: that'd be great!
08:09	SagiCZ1	the thing is.. i am using swing for rendering, i.e. paintComopnent method which has fixed amount of arguments.. how could i pass the state in there?
08:09	lvh	clgv: looks
08:09	lvh	llasram: some parts of the alphabet
08:09	lvh	llasram: + and /, specifically
08:09	llasram	Ah, of course
08:10	clgv	SagiCZ1: do you use seesaw?
08:10	SagiCZ1	clgv: yes
08:11	lvh	clgv: there's https://github.com/clojurewerkz/route-one, but it doesn't appear to know anything about base64.
08:11	clgv	SagiCZ1: well, you can easily build closures as paint handlers, that close over the game state atom. on each paint call you deref the atom
08:11	SagiCZ1	clgv: either the entities i want to render must be global or the canvas i want to paint on must be global
08:12	SagiCZ1	yeah using clojure while not understanding closures sounds like a terrible idea
08:13	clgv	SagiCZ1: the functions that do the actual painting cant be pure of course, but the game logic that updates the state can be
08:14	SagiCZ1	they cant be pure because the fact that they actually "paint on screen" is a side-effect right?
08:15	clgv	lvh: the contrib lib data.codec has base64 encoding but it's also a bigger dependency...
08:16	clgv	SagiCZ1: yeah. but functions that determine how something needs to be painted (e.g. color dependend on several state values) can be pure
08:17	SagiCZ1	clgv: could u write a pseudocode example of this please? "well, you can easily build closures as paint handlers, that close over the game state atom. on each paint call you deref the atom"
08:20	clgv	SagiCZ1: here is the example how to add a paint handler https://github.com/daveray/seesaw/blob/master/test/seesaw/test/examples/paintable.clj#L31
08:22	SagiCZ1	i am using that.. but the "draw-a-red-x" is not "closing over" anything is it?
08:23	clgv	SagiCZ1: in the function creating your gui you could do something like (defn create-gui [game-state-atom, ...] (<CANVAS-COMPONENT> ... :paint (fn [component, graphics] (let [game-state @game-state] ....paint...))))
08:23	SagiCZ1	clgv: now i see it.. perfect!
08:23	clgv	SagiCZ1: just replace <CANVAS-COMPONENT> with whatever you use as canvas
08:24	clgv	change "@game-state" to "@game-state-atom"
08:24	SagiCZ1	yeah.. no the atom does not have to be global
08:24	SagiCZ1	*now
08:29	lvh	Is there a ring/compjure thing that lets me say "this part of the URL is a base64 thing; please give me the decoded version"
08:36	SagiCZ1	clgv: back your example.. is it possible to create the inner function somewhere else for clarity? or it has to be nested to access the atom?
08:38	SagiCZ1	clgv: maybe i should have a "factory-function" that can output a function with the closure?
08:41	jeffterrell	lvh: I found ring.util.codec/base64-{en,de}code here: http://mmcgrana.github.io/ring/ring.util.codec.html
08:41	jeffterrell	lvh: Does that work for you?
08:41	lvh	jeffterrell: yeah, me too. Not urlsafe though.
08:41	lvh	jeffterrell: (also doesn't automagically do the encoding btu I can live with that
08:43	jeffterrell	Fair enough.
08:44	lvh	I wish clojure.string.trim let me specify which chars I wanted to trim
08:46	SagiCZ1	i would like to call a function n times to generate a list of n items, how do i do that?
08:46	hyPiRion	(repeatedly n fun)
08:46	hyPiRion	it's lazy though, so be aware of that
08:46	hyPiRion	,(repeatedly 10 rand)
08:46	clojurebot	(0.5949458375138312 0.08279190123529145 0.14265751227133672 0.07628975550512085 0.7772873079770356 ...)
08:47	SagiCZ1	hyPiRion: thats what i want
08:47	SagiCZ1	ty
08:48	SagiCZ1	,(repeatedly 4 #(0))
08:48	clojurebot	#<ClassCastException java.lang.ClassCastException: java.lang.Long cannot be cast to clojure.lang.IFn>
08:48	SagiCZ1	why this doesnt work though?
08:49	SagiCZ1	,(repeatedly 4 (fn [] 0))
08:49	clojurebot	(0 0 0 0)
08:49	SagiCZ1	and now it does??
08:49	lazybot	SagiCZ1: Definitely not.
08:50	SagiCZ1	,(repeatedly 4 #((0)))
08:50	clojurebot	#<ClassCastException java.lang.ClassCastException: java.lang.Long cannot be cast to clojure.lang.IFn>
08:50	hyPiRion	SagiCZ1: What is (0) ?
08:50	SagiCZ1	i just want a function that returns 0
08:50	SagiCZ1	this is not correct? #(0) ?
08:50	clgv	SagiCZ1: (constantly 0)
08:50	r4vi	(0) is trying to function call a Long
08:50	hyPiRion	If you want a constant you could use (repeat 4 0), btw
08:51	clgv	,(read-string "#(0)")
08:51	clojurebot	(fn* [] (0))
08:51	clgv	SagiCZ1: ^^ that's why
08:51	riffraff	(repeatedly 4 #( 0 ) ) wouldn't work either though, why?
08:51	clgv	riffraff: see above
08:51	SagiCZ1	it wraps it with another set of braces
08:51	hyPiRion	,'#(0)
08:51	clojurebot	(fn* [] (0))
08:51	riffraff	ahihi, got it
08:51	clgv	hyPiRion: uhh shortcut :D
08:52	SagiCZ1	,(constanly rand)
08:52	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: constanly in this context, compiling:(NO_SOURCE_PATH:0:0)>
08:52	SagiCZ1	,(constantly rand)
08:52	clojurebot	#<core$constantly$fn__4178 clojure.core$constantly$fn__4178@147fc78>
08:52	SagiCZ1	,((constantly rand))
08:52	clojurebot	#<core$rand clojure.core$rand@15e8c9d>
08:52	hyPiRion	that's a function returning the function rand all the time
08:52	SagiCZ1	,((constantly (rand)))
08:52	clojurebot	0.3298967693738979
08:53	SagiCZ1	,(repeatedly 5 #(constantly (rand)))
08:53	clojurebot	(#<core$constantly$fn__4178 clojure.core$constantly$fn__4178@b873c> #<core$constantly$fn__4178 clojure.core$constantly$fn__4178@dbb0af> #<core$constantly$fn__4178 clojure.core$constantly$fn__4178@12cea05> #<core$constantly$fn__4178 clojure.core$constantly$fn__4178@1b7fb2c> #<core$constantly$fn__4178 clojure.core$constantly$fn__4178@1cb30a4>)
08:53	SagiCZ1	nevermind
08:53	clgv	,(repeatedly 5 (constantly (rand)))
08:53	clojurebot	(0.17791487825993624 0.17791487825993624 0.17791487825993624 0.17791487825993624 0.17791487825993624)
08:53	clgv	SagiCZ1: no idea why you want it that complicated but that works ^^
08:54	clgv	,(repeat 5 (rand))
08:54	clojurebot	(0.9761251033774431 0.9761251033774431 0.9761251033774431 0.9761251033774431 0.9761251033774431)
08:54	clgv	SagiCZ1: same effect ^^
08:54	SagiCZ1	clgv: ^^ just playing around
08:55	SagiCZ1	so is there a nicer way to do exactly this?
08:55	SagiCZ1	,(repeatedly 4 (constantly {:a 0 :b (rand)}))
08:55	clojurebot	({:a 0, :b 0.49531751143064073} {:a 0, :b 0.49531751143064073} {:a 0, :b 0.49531751143064073} {:a 0, :b 0.49531751143064073})
08:56	SagiCZ1	,(repeat 2 {:a 0 :b (rand)})
08:56	clojurebot	({:a 0, :b 0.8084007871336014} {:a 0, :b 0.8084007871336014})
08:56	SagiCZ1	got it
09:02	hyPiRion	you want (rand) to be the same value for each item? Asking, just to ensure you get the right thing out
09:03	lvh	What's the idiomatic data structure in Clojure for bytestrings?
09:03	lvh	I've been using bytes[] but that just feels super gross.
09:04	clgv	hyPiRion: yeah, looks like a code smell. should be something like (let [r (rand)] (repeat 5 {:a 0 :b r})) to make the intention clear
09:05	SagiCZ1	hyPiRion: nope that is a mistake
09:05	SagiCZ1	hyPiRion: why is not calling random again?
09:05	justin_smith	lvh: you can use a vector of Byte values, byt bytes[] is an actual array of bytes, and is the right way to represent that
09:06	lvh	justin_smith: also mutable though right
09:06	justin_smith	right
09:06	justin_smith	what do you mean by "bytestring", actually?
09:07	justin_smith	arrays of bytes are not CharSequences because they are made of 8 bit signed values
09:07	llasram	SagiCZ1: Because you are calling it yourself vs passing the function `rand` to something
09:07	llasram	,(repeatedly 5 rand)
09:07	clojurebot	(0.013326642964774371 0.40762242985735264 0.7708784528135172 0.9785686587084479 0.7638473865027904)
09:07	justin_smith	lvh: maybe you want an array of shorts, or even ints, if you want to represent anything beyond 8 bits
09:08	SagiCZ1	,(repeatedly 2 (fn [] {:a (rand) :b (rand)}))
09:08	clojurebot	({:a 0.7095231468043378, :b 0.2359827909847596} {:a 0.7883582125143982, :b 0.8835072257869794})
09:08	SagiCZ1	this is what i want
09:08	SagiCZ1	i just dont like the fn notation
09:08	clgv	SagiCZ1: so why dont you use it? that why? :P
09:08	clgv	*way
09:08	SagiCZ1	clgv: fn seems uncool to me
09:08	SagiCZ1	especially with no arguments
09:09	hyPiRion	SagiCZ1: ##(map #(assoc {:a 0} :b %) (repeatedly 2 rand))
09:09	lazybot	⇒ ({:b 0.7055591223129442, :a 0} {:b 0.004841332288907818, :a 0})
09:09	llasram	SagiCZ1: No no -- `fn` is the coolest
09:09	justin_smith	,(repeatedly #(hash-map :a (rand) :b (rand)))
09:09	clojurebot	({:b 0.7774605426166392, :a 0.5457287633034817} {:b 0.9351205665136824, :a 0.10940327234871117} {:b 0.2785826781824663, :a 0.06663172148153373} {:b 0.6237813005636965, :a 0.6235348439569292} {:b 0.2189573584793213, :a 0.11105258859414224} ...)
09:10	justin_smith	yes, fn is awesome
09:10	SagiCZ1	thanks for the ideas
09:10	llasram	,(repeatedly 2 #(-> {:a (rand)}))
09:10	clojurebot	({:a 0.3764276763964761} {:a 0.28425055137631283})
09:10	clgv	SagiCZ1: doh!
09:10	lvh	justin_smith: I mean bytestrings as in sequences of bytes. Like a C string, or a Python string.
09:10	lvh	justin_smith: Not like a java String, of course.
09:10	llasram	lvh: s/Python string/Python 2 string/
09:10	justin_smith	lvh: yeah, byte-array is that (and is of course mutible)
09:11	lvh	llasram: python3 doesn't exist ;)
09:11	llasram	:-p
09:13	SagiCZ1	another question.. if i want to have an inner function close over some local symbol, can i define it somewhere outside?
09:13	SagiCZ1	scratch that..
09:14	justin_smith	you can pass local values to a function that creates a new function closing over those values
09:14	SagiCZ1	yep.. gonna do just that
09:14	justin_smith	like the classic make-adder
09:30	SagiCZ1	can i deref atom by destructuring? (doseq [{a :a b :b} [(atom {:a 0 :b 1}) (atom {:a 2 :b 3})]] (println a b))
09:31	clgv	SagiCZ1: no not like that. first deref it to get the value then apply destructuring on the value
09:32	SagiCZ1	ok
09:32	justin_smith	,(let [{a :a} (atom {:a 42})] a)
09:32	clojurebot	nil
09:32	justin_smith	,(let [{a :a} @(atom {:a 42})] a)
09:32	clojurebot	42
09:32	SagiCZ1	yeah that works for let, but not for doseq when u have a coll of atoms
09:32	justin_smith	you can destructure an atom, it just won't return the value you want
09:33	justin_smith	SagiCZ1: doseq and let use exactly the same destructuring
09:33	vladh_	Hey guys — does anyone know how I can keep a script running via lein-exec? I’m trying to run a simple cron-style thing with at-at and don’t want to script to immediately.
09:33	vladh_	to die*
09:33	SagiCZ1	justin_smith: no they dont?
09:34	justin_smith	SagiCZ1: doseq needs a sequence, but doseq and let both call clojure.core/destructure to do destructuring
09:34	SagiCZ1	doseq does that for each element of the sequence separately though
09:35	justin_smith	sure - so it destructures each element of the sequence
09:35	justin_smith	I am just saying the actual destructuring, when it happens, is done by the same function
09:35	SagiCZ1	alright..
09:35	SagiCZ1	i see
09:36	justin_smith	and my ,(let [{a :a} (atom {:a 42})] a) is exactly analogous to your (doseq [{a :a b :b} [(atom {:a 0 :b 1}) (atom {:a 2 :b 3})]] (println a b))
09:37	justin_smith	but I switched to let because there is less noise there, and the destructuring happens in the same manner
09:37	SagiCZ1	but in let u can solve the problem with prepending @ to the right sight of the binding.. in doseq u cant
09:38	llasram	wat
09:38	justin_smith	(doseq [{a :a b :b} (map deref [...])] ...)
09:38	SagiCZ1	oh.... wow
09:38	SagiCZ1	mind - blown
09:38	llasram	SagiCZ1: @ is a reader macro for `deref`
09:38	llasram	,`@whatever
09:38	clojurebot	(clojure.core/deref sandbox/whatever)
09:38	SagiCZ1	thats news to me
09:39	clgv	SagiCZ1: well you should probably read the chapter on atoms and refs ^^
09:39	SagiCZ1	clgv: i read it so many times .. i just figured that i should also write some code to help me remember
09:40	SagiCZ1	my theoretical knowledge of clojure is higher than the practical experience.. im not saying it's very high anyways
09:40	clgv	SagiCZ1: use the chapter while writing code ;)
09:40	SagiCZ1	alright
09:41	lvh	Is x.y.z-SNAPSHOT before, or after x.y.z?
09:41	llasram	lvh: "Before", but snapshots are non-release, so you have no way of knowing what's in one
09:42	justin_smith	llasram: well you can always look inside :P
09:42	justin_smith	but yeah, no way to know beforehand what you'll get if you ask for it
09:42	llasram	justin_smith: Except that the non-pinned SNAPSHOT revision could be updated at any time
09:42	clgv	lvh: use snapshots only for experimenting with new features that are not in any release, since they might sabotage repeatable builds
09:43	lvh	I'm trying to publish software thoguh :)
09:43	justin_smith	llasram: I meant you can check strictly a-posteriori, but really that hardly matters compared to not knowing what you'll get if you ask for it
09:45	clgv	lvh: well at the end of a dev cycle release a non-snapshot, during the dev cycle you can use snapshot versions
09:46	lvh	ok :)
09:48	zeebrah	Y do i need do add the eval here: ((eval (read-string "first")) [1 2 3])
09:48	llasram	zeebrah: mu
09:49	zeebrah	llasram: dont know mmu
09:49	clgv	zeebrah: because you are doing weird stuff ;) a `resolve` would suffice
09:50	clgv	,((resolve (read-string "first")) [1 2 3])
09:50	clojurebot	1
09:50	zeebrah	clgv: i'm watching bob martin so yes definitely weird :)
09:50	clgv	,((resolve 'first) [1 2 3])
09:50	clojurebot	1
09:50	clgv	same ^^
09:50	clgv	,(first [1 2 3])
09:50	clojurebot	1
09:50	zeebrah	so resolve is taking a symbol and then finding the function? but why is that necessary
09:51	llasram	zeebrah: Needing to manually `read` string which contain code is unusual, and probably means there's a more common way to do whatever you're trying to do
09:51	llasram	zeebrah: Or do you just want to understand why a symbol is not identical to the function a particular namespaces maps that symbol to?
09:51	zeebrah	llasram: just trying something out because the dude said you can build lisp code and then execute it using eval
09:51	zeebrah	llasram: i guess :)
09:52	zeebrah	if the symbol is in function position then why doesn't it just work as I expected?
09:52	clgv	zeebrah: what are you watching exactly?
09:52	zeebrah	https://www.youtube.com/watch?v=SYeDxWKftfA
09:52	justin_smith	zeebrah: the normal way is to just type into the repl, it does the eval and read for you
09:52	clgv	zeebrah: since the symbol is a symbol and is not a function
09:52	llasram	zeebrah: So in Clojure (and most Lisps) "reading" and "compiling" are separate steps
09:53	llasram	Reading turns text into a data-structure
09:53	llasram	Compilation turns a data-structure into code
09:53	zeebrah	clgv: right but its not like there are multiple namespaces so there isnt any ambiguity in just using the only one in the namespace?
09:53	clgv	so Uncle Bob uses Clojure, eh?
09:53	zeebrah	apparently!
09:54	clgv	you explicitly constructed a symbol in your example, so no it can not
09:54	zeebrah	is namespace the right word there? i mean in the sense of lisp 1 and 2
09:54	clgv	if you just put a symbol in call position it is resolved to a function on compilation or an error is thrown
09:54	llasram	zeebrah: In that sense Clojure is a Lisp-1 and has only one "namespace", but it has a concept of namespaces (like CL packages), so the same bare symbol could refer to multiple functions in different namespaces
09:54	zeebrah	oh i see
09:55	justin_smith	symbols can have namespaces, but a bare one doesn't - but it gets resolved according to the mappings of the current namespace to a var
09:55	llasram	^^ During compilation
09:55	clgv	justin_smith: but not in his case where he explicitely constructed a "symbol value"
09:55	llasram	(well, or manual resolution via e.g. `resolve`)
09:56	justin_smith	,(map namespace '[foo user/foo sandbox/foo clojure.string/foo])
09:56	clojurebot	(nil "user" "sandbox" "clojure.string")
09:56	justin_smith	clgv: right, not always resolved - but it uses the same rules once you ask for it to be resolved
09:58	zeebrah	so the reason ((read-string "first") [1 2 3]) didnt return 1 is b/c first doesn't yet belong to a namespace but yet it is still a symbol
09:59	justin_smith	it's just the symbol, not the var the symbol points at
09:59	justin_smith	,((read-string "clojure.core/first") [1 2 3]) ; this is no better
09:59	clojurebot	nil
10:00	justin_smith	resolve says "find the var for this symbol"
10:00	zeebrah	oh
10:00	hyPiRion	,('+ 1 2)
10:00	clojurebot	2
10:00	justin_smith	,((read-string "clojure.core/first") [1 2 3] 1) ;P
10:00	clojurebot	1
10:01	justin_smith	that's just a trick
10:01	zeebrah	so how is this not like a lisp-2 doing (function ..) first? i thought going to a lisp 1 made that unnecessary
10:01	zeebrah	hmmm interesting
10:01	hyPiRion	zeebrah: Because a symbol is not a function
10:02	justin_smith	zeebrah: in normal code, you type the name of the function, and it gets the value pointed at by the var indicated by the symbol
10:02	zeebrah	understood thanks :)
10:02	justin_smith	,(let [plus +] (plus 1 1))
10:02	clojurebot	2
10:02	justin_smith	can't do that in a lisp-2
10:03	hyPiRion	Right. (let ((plus #'+)) (funcall plus 1 1)) is the closest
10:03	justin_smith	which reminds me I should make my above statement more precise: it gets the value pointed at by the local binding, or failing that, var resolution
10:04	zeebrah	does scheme have a version of resolve too?
10:05	SagiCZ1	lets say i refer to a different ns "other-ns" using :require in my (ns) .. i am working in the current ns in repl.. what if i want to change a function in the "other-ns" and reflect the change in my working repl? should i call (ns) again to :require it again? it didnt reflect the changes
10:05	xeqi	does ` have a name?
10:05	justin_smith	xeqi: syntax-quote
10:06	xeqi	quasi-quote, symbol-quote ..
10:06	xeqi	ah
10:06	xeqi	thanks
10:06	hyPiRion	I've always referred to it as backquote
10:06	justin_smith	zeebrah: I think in scheme eval is more likely to be used
10:06	hyPiRion	but that's cl history I guess
10:06	justin_smith	here it is called syntax-quote http://clojure.org/reader
10:06	mi6x3m	clojure
10:06	mi6x3m	what is a way to extract only a subset of the keys in a map?
10:07	mi6x3m	like (subset map [:a :b :c])
10:07	justin_smith	select-keys
10:07	mi6x3m	,(doc select-keys)
10:07	clojurebot	"([map keyseq]); Returns a map containing only those entries in map whose key is in keys"
10:07	justin_smith	,(select-keys {:a 0 :b 1} [:a])
10:07	clojurebot	{:a 0}
10:07	SagiCZ1	cfleming: hi, are you here by any chance?
10:08	mi6x3m	(inc justin_smith)
10:08	lazybot	⇒ 71
10:18	SagiCZ1	ok let me ask once again.. how do i reload a library in repl?
10:19	clgv	SagiCZ1: library or namespace of the current project?
10:19	SagiCZ1	other namespace
10:19	clgv	usually you use "send to repl" or something similar which your ide/editor provides
10:20	SagiCZ1	ok i just tried that and it owrks
10:20	SagiCZ1	works
10:20	SagiCZ1	i thought there is some programatic way
10:20	clgv	SagiCZ1: well yeah, there is but you'll end up with tools.namespace then
10:20	SagiCZ1	yeah i dont want that..
10:21	clgv	+likely
10:21	SagiCZ1	but this works so thats fine
10:22	justin_smith	SagiCZ1: (require 'some.ns :reload) works in a vanilla repl
10:22	SagiCZ1	justin_smith: thank you
10:23	justin_smith	clgv: the reason to use tools.namespace there is if a definition is removed from the ns, :reload does not undefine it, right? or is there some other nuance?
10:27	clgv	justin_smith: types and records are problematic. if you redefine a type by reloading its defining namespace other functions from different namespaces that were not reloaded but use that type will break
10:27	justin_smith	ahh, right
10:28	lvh	I have a bunch of forms in a threading macro. I want to conditionally add one. Is there a reasonable trick for that?
10:28	clgv	justin_smith: that's an example from my experience where using require only will break
10:29	elazar	Trying to go through Clojure koans: https://github.com/functional-koans/clojure-koans. Hitting an issue with cons. http://pastebin.com/raw.php?i=mkPrG1zn Any suggestions?
10:29	justin_smith	elazar: note how they create the sequence you are consing onto?
10:30	justin_smith	*they are consing onto
10:30	elazar	Ah, I think I see.
10:30	justin_smith	you have to do the same thing with your sequence
10:30	elazar	Well, I'm a little further now. Thank you, justin_smith. :)
10:30	justin_smith	,[(:a :b :c :d :e) '(:a :b :c :d :e)]
10:30	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: Wrong number of args passed to keyword: :a>
10:31	justin_smith	:a is a keyword, it invokes get on its args if used in a function position
10:32	elazar	,(= (quote (:a :b :c :d :e)) (conj (quote (:a :b :c :d)) :e))
10:32	clojurebot	false
10:33	justin_smith	conj is a little funny ##(= (conj [:a :b] :c) (conj '(:a :b) :c))
10:33	lazybot	⇒ false
10:34	elazar	,(= (quote (:e :a :b :c :d)) (conj (quote (:a :b :c :d)) :e))
10:34	clojurebot	true
10:34	elazar	^ Yeah, figured it out. :)
10:34	elazar	http://clojuredocs.org/clojure_core/clojure.core/conj <-- second example
10:34	elazar	Sorry, first example, second input.
10:35	justin_smith	,(conj #{:a :b :c :d} :e)
10:35	clojurebot	#{:e :c :b :d :a}
10:48	maxthoursie	lvh: cond-> ?
11:41	sm0ke	using java.jdbc is there a way to preserve order of columns?
11:42	sm0ke	select a,b,c from ... gives {:a 1 :b 2 :c 3} which loses the order
11:42	bja	sm0ke, I can't imagine relying on ordering there is safe
11:44	sm0ke	yes, that is why i am asking, jdbc result is ordered
11:44	bja	https://github.com/clojure/java.jdbc/blob/master/src/main/clojure/clojure/java/jdbc.clj#L800
11:45	bja	it looks like query takes :as-arrays? true to make the result set fn into vdc
11:45	bja	I didn't try it, but it sounds exactly like what you want
11:45	sm0ke	let me try
11:45	sm0ke	thanks bja
11:47	sm0ke	ugh, that is for the outer data structure
11:47	sm0ke	[{},..] instead of '({},..)
11:48	bja	oh
11:48	bja	it looks like the code maps :row-fn across the results
11:49	sm0ke	row-fn is identity by default so internally it is map as lower denominator
11:49	sm0ke	sad
11:50	justin_smith	(map (fn [k] [k (m k)] [:a :b :c])
11:50	justin_smith	)
11:50	justin_smith	where m is the result, and that last arg has the order you want?
11:51	sm0ke	well thats not the point
11:51	justin_smith	what is the point?
11:52	bja	sm0ke, https://github.com/clojure/java.jdbc/blob/master/src/main/clojure/clojure/java/jdbc.clj#L362 exists to turn the raw ResultSet into a seq of maps
11:53	sm0ke	ugh read the comment
11:53	sm0ke	sad
11:54	luqi	Hello everyone. As a beginner in Clojure, I find it really daunting when things go wrong and the stack trace is just huge. Any suggestions on it?
11:54	sm0ke	hmm there is a interesting comment which says "but using into {} should preserve order for up to 16 columns"
11:56	clgv	sm0ke: do you need additional features of the default clojure.java.jdbc functions? if not just write a function that handles the resultset directly
11:56	bja	sm0ke, maybe you only need 16 columns? :(
11:56	justin_smith	luqi: there are various tools for colorizing output to help you find the relevant parts
11:56	sm0ke	no i need more
11:57	sm0ke	grr.. i will have to go back to basic jdbc
11:57	justin_smith	luqi: at this point, I have learned how to read the stacktraces, and I look for the frames that are in files I wrote.
11:58	luqi	yeah, I always look for my files. but they are kinda buried inside massive Java/JVM frames
11:59	justin_smith	luqi: https://github.com/AvisoNovate/pretty
12:00	justin_smith	luqi: this ns in particular https://github.com/AvisoNovate/pretty/blob/master/src/io/aviso/exception.clj
12:00	sm0ke	(inc bja)
12:00	lazybot	⇒ 1
12:00	sm0ke	(inc bja)
12:00	lazybot	⇒ 2
12:00	justin_smith	in particular, write-exception
12:00	sm0ke	seems like i was missing the "?" in :as-arrays?
12:00	luxbock	luqi: if you are using Emacs, I find the cider-stacktrace mode you get with C-c C-s pretty helpful
12:01	sm0ke	:as-arrays? indeed is the solution!
12:01	clojer	Anyone know what this compilation error refers to: "NullPointerException clojure.lang.Numbers.ops (Numbers.java:961)" ?
12:01	justin_smith	clojer: you tried to do math on nil
12:01	justin_smith	,(+ nil 1)
12:01	clojurebot	#<NullPointerException java.lang.NullPointerException>
12:01	bja	nice
12:01	luqi	justin_smith, yeah this looks much nicer!
12:02	clojer	justin_smith: Great, but why doesn't the error come with a line number?
12:02	luqi	luxbock: I am using Vim primarily but I'd love to learn Emacs :)
12:02	justin_smith	luqi: awesome, our own hlship (not online right now) worked on it, and introduced me to it
12:02	luxbock	I use Emacs with evil, which is pretty close to Vim
12:03	justin_smith	clojer: Numbers.java - on another stack frame you may find a line number in your own code
12:03	luqi	Aha, that's actually what I'm thinking about
12:03	clojer	justin_smith: How do I get that in Emacs/cider?
12:03	zwer	join #java
12:03	justin_smith	luxbock: luqi: as far as I am concerned, getting cider to work would be a terrible way to learn emacs
12:04	justin_smith	clojer: (pst)
12:04	clgv	~guards
12:04	clojurebot	SEIZE HIM!
12:04	clgv	joining #java tsk tsk tsk
12:05	justin_smith	luxbock: luqi: I subscribe to that repo's issues feed, I intend to switch to cider when the bug reports slow down (if they ever do)
12:05	justin_smith	(cider's that is)
12:05	clojer	justin_smith: Brilliant. You're a life-saver.
12:05	justin_smith	clojer: np - I think the decision to only show one line of the exception by default is kind of silly
12:06	justin_smith	clojer: also you can access the last uncaught exception object thrown using *e
12:06	clojer	(pst)
12:06	luxbock	I think the cider-stracktrace mode as a more convenient version of pst
12:07	justin_smith	if you want to assign the exception to some var to do something with later, or write your own code that analyzes the exception, *e is quite handy
12:07	clojer	justin_smith: Damn. I posted this on the clojure mailing list not realising that was a truncated error message :(
12:08	justin_smith	I'm sure this isn't the first or last cider bug / cider UI deficiency that has ended up there
12:09	clojer	justin_smith: Yes and I'm stuck with cider 0.6 as I'm using Emacs Live awaiting the 0.7-compatible update :(
12:09	nbeloglazov	In order to send pull requrest/patches to libs under clojure namespace (e.g. tools.reader) do I have to sign contributor agreement?
12:09	justin_smith	~emacslive
12:09	clojurebot	No entiendo
12:10	clojer	justin_smith: My Emacs foo is pretty non-existent :(
12:10	luxbock	is there something about Emacs Live that preventes you from getting the latest cider-version from elpa/melpa?
12:10	justin_smith	clojer: emacs live is easy to port to regular emacs, and you can even switch between the two by specifying the config files to run on launch. See also technomancy's https://github.com/technomancy/better-defaults
12:11	clojer	justin_smith: I often wondered if that could be done but never found the details.
12:11	justin_smith	luxbock: not really - but the point of emacs live is you don't want to mess with your own configs freeform yet - you want a compatible zero-effort it just works setup out of the box
12:11	justin_smith	clojer: it's doable, just not compatible with the whole "it just works" thing :)
12:11	clojer	justin_smith: Problem I had in the past was `git submodule <something or other>` wiping out my customisations
12:12	luxbock	hmm right, I think I started out with one of the starter kits and then ditched most of it once I got a handle of how things worked
12:12	justin_smith	clojer: put your .emacs.d under git version control :)
12:12	clojer	justin_smith: Yes, I like what "just works" with Emacs Live
12:12	justin_smith	luxbock: clojer: see the readme from technomancy 's better defaults repo I linked above, has a really good sumarry of the situation
12:13	clojer	justin_smith: Unfortunatley Dr. Sam Aaron is a bit tied up right now to finish testing Cider 0.7 compatibility
12:14	clojer	justin_smith: There's an update in the dev packs somewhere but I'd rather not mess about
12:14	justin_smith	fair enough, you could be patient, save yourself some pain, and wait for him to do it, or go through the pain and make it work yourself (or maybe "just barely work, good enough for now")
12:15	clojer	justin_smith: I'll defer to his greater Emacs skills. Emacs Live is great for my laziness, hubris & impatience :)
12:16	justin_smith	clojer: in terms of switching configs, the default config is ~/.emacs.d/init.el (or ~/.emacs for legacy, but that is not recommended) - you can launch emacs -q -l alternate-init.el to use a different init file
12:16	clojer	justin_smith: OK, sounds like it's worth a try.
12:16	justin_smith	this is useful while experimenting, you can copy init.el and then use -q -l to launch an emacs using the alternate, modified init
12:16	justin_smith	without breaking your default init file
12:17	riffraff	mh how does one get a vector of ints with a skewed distribution with test.check? I tried (gen/vector (gen/frequency [[ 50 gen/int 5] [50 gen/int 100]])) but it doesn't seem to work
12:17	martinklepsch	whats (go (while true) ... ) good for?
12:18	reiddraper	riffraff: you just need [50 gen/int 5] [50 gen/int 100] isn't a valid syntax for gen/frequency. What are you trying to achieve with that/
12:18	justin_smith	martinklepsch: I assume that's (go (while true (do-async-things)))
12:18	martinklepsch	In clojure it seems to be the default in clojurescript it kills my browser
12:19	reiddraper	riffraff: err, ignore the 'you just need' part of that message
12:19	justin_smith	martinklepsch: related to the fact that js has no threads maybe?
12:20	riffraff	reiddraper, I was trying to say "get a frequency of 50% ints in 0..5 and 50% in 0..100"
12:20	reiddraper	riffraff: use gen/choose to create ranges
12:21	riffraff	isnot gen/choose 0 y the same as gen/int y ?
12:21	reiddraper	riffraff: (def f (gen/frequency [[50 (gen/choose 0 5)] [50 (gen/choose 0 100)]]))
12:22	dnolen_	martinklepsch: it not the default in Clojure either - that will result in burning CPU cycles doing nothing
12:22	riffraff	mh, apparently not
12:22	riffraff	thanks!
12:22	reiddraper	riffraff: no. And if it were, you'd need parenthesis around (gen/int x)
12:22	martinklepsch	dnolen_: you're right, I had those examples wrong in my memories.
12:24	riffraff	I see, I must have tried [5 (gen/int x)], got an error, tried [5 gen/int x], saw it not exploding and moved on
12:25	martinklepsch	so in (go (while true (do-something (<! c)))) —VS— (go (do-something (<! c))) is the (while true ... useful in what scenario?
12:49	dnolen_	martinklepsch: there aren't really cases where (while true ...) is desirable beyond demo examples, you almost always want loop/recur with some exit condition
12:49	devn	using slime + lein-swank again
12:55	justin_smith	devn: how is it?
12:55	devn	simpler
12:57	justin_smith	is that an endorsement? it sounds like an endorsement
13:24	riffraff	Okasu, one last thing I don't really understand about test.check and the above mentioned test. I'd expect to run (tc/quick-check 10 my-prop) and have it test ten random sequencies in a few seconds
13:24	riffraff	(sorry okasu, I meant "ok", darn autocomplete)
13:25	riffraff	what appears to happen is that the repl runs forever visiting tens of thousands of nodes
13:34	reiddraper	riffraff: does your test fail?
13:35	reiddraper	if so, then what you are seeing is something called shrinking. depending on your generators and property, the shrinking process may have to do a large search
13:36	clgv	reiddraper: is there a possibility to limit the shrinking search or turn it off completely. On occasions this makes sense.
13:38	reiddraper	clgv: you can wrap your generator (or even your whole property) in gen/no-shrink
13:38	reiddraper	there isn't a way (yet) to pause/cancel/limit shrinking otherwise
13:41	grincher	change the value of the string if the value contains a specific substring? Eg. map = {:a "nora", :b "sara}; if VALUE contains "nora" replace with "bob", if VALUE contains "ra" replace with "ma" etc
13:42	grincher	Sorry, how can I iterate a nested map and change the value of the string if the value contains a specific substring? Eg. map = {:a "nora", :b "sara}; if VALUE contains "nora" replace with "bob", if VALUE contains "ra" replace with "ma" etc
13:42	clgv	reiddraper: ok thx
13:42	riffraff	reiddraper, I think that may be it cause if I try to trace the checking of my property I can see it executed a ton of times, but is there a way to ask the quick-check method to fail fast?
13:43	reiddraper	riffraff: wrap the property in gen/no-shrink to disable shrinking
13:43	riffraff	ah perfect thanks
13:43	reiddraper	(tc/quick-check 10 (gen/no-shrink my-prop))
13:44	riffraff	I didn't notice this in the docs, seems what I need thank you very much
13:45	reiddraper	riffraff: not documented at the moment
13:46	justin_smith	,(reduce-kv (fn [m k v] (assoc m k (-> v (clojure.string/replace #"^nora$" "bob") (clojure.string/replace #"ra" "ma")))) {} {:a "nora" :b "sara"}) ; grincher
13:46	clojurebot	{:a "bob", :b "sama"}
13:47	grincher	thank you justin_smith :)
13:48	justin_smith	of course in real code you would require clojure.string :as string and string/replace
13:48	justin_smith	or something like that
13:49	justin_smith	also if you don't want the substitutions to stack, you would want a cond rather than ->
13:53	grincher	justin_smith, I am getting some "clojure.lang.LazySeq@d055e162" istead of the "bob" value
13:53	justin_smith	with what code? care to share on refheap or a gist?
13:59	gfredericks	,(clojure.string/replace (str (range 10)) #"clojure\.lang\.LazySeq@[0-9a-f]{8}" "bob")
13:59	clojurebot	"bob"
13:59	justin_smith	lol
14:00	justin_smith	grincher: if you did a lazy op on a string, then you can get a string out the other end with (apply str ...)
14:00	justin_smith	grincher: in my example there are no lazy ops, which is why I asked to see a paste
14:11	grincher	justin_smith, https://gist.github.com/gildo/d8f3c6f7614df2368479
14:15	justin_smith	OK - I don't see anything there where the "bzip2" value would become a lazy-seq
14:15	justin_smith	what yaml lib are you using? I will see if I can reproduce.
14:17	grincher	justin_smith, in line 3 you can find the the parsed yaml
14:17	grincher	line 3 == x
14:17	justin_smith	can you share the pr-str version?
14:17	justin_smith	that verison is not readable
14:18	justin_smith	ie. the result of (pr x) or (println (pr-str x))
14:19	grincher	justin_smith, gist updated
14:19	grincher	I'am using [circleci/clj-yaml "0.5.2"]
14:22	martinklepsch	I'm trying to write a transducer that takes a map and runs a few api calls based on the maps input, kind of pipelining the output of the first transducer function to the second and so on.
14:23	justin_smith	grincher: https://www.refheap.com/89666 I get bob as expected (see the last line)
14:24	justin_smith	I do see some lazy-seq output there though! I see what you mean.
14:24	martinklepsch	now I have a function that looks kind of like the following https://gist.github.com/mklappstuhl/67a7cde18575ecf4e39d — point is it takes a callback function to return it's result. how do I properly feed that back into the flow of the transducing function?
14:25	martinklepsch	do I put it in a channel and take from that channel at the end of that function?
14:26	martinklepsch	am I maybe on the wrong path using transducers here?
14:27	Bronsa	,(clojure.string/replace (range 10) #"" "")
14:27	clojurebot	"clojure.lang.LazySeq@9ebadac6"
14:27	Bronsa	justin_smith: ^
14:27	justin_smith	grincher: https://www.refheap.com/89666 updated, no longer tries to regex replace non-strings
14:27	justin_smith	Bronsa: yeah, I just caught that :)
14:28	justin_smith	I guess I can take the apply str out to, for that matter
14:31	justin_smith	grincher: of course you may want to go deeper and recursively work on some of the values that are not strings, updating the strings inside, but what's there should be a start
14:33	grincher	thank you justin_smith
14:35	justin_smith	np
14:40	justin_smith	,(update-in {:a {:b "value"}} [:a :b] str " modified") ; grincher
14:40	clojurebot	{:a {:b "value modified"}}
14:46	joobus	can someone give me an example of how to use with-open? I was using slurp to fetch a webpage in the repl, but then if i fetched the same page again the output was all garbled. I think it had something to do with not closing the file descriptor.
14:47	justin_smith	joobus: slurp closes the file descriptor
14:47	joobus	hmmm
14:47	justin_smith	joobus: and generally, things like streams get closed properly if they go out of scope in the jvm.
14:48	justin_smith	and given that the stream slurp opens never enters your scope...
14:48	joobus	i guess it was the page i was slurping then
14:48	tenchi	?reduce
14:49	justin_smith	~reduce
14:49	clojurebot	reduce accumulates the men from the boys
14:49	justin_smith	haha
14:49	tenchi	justin_smith: Haha...no just a chat issue (not clojure).
14:49	justin_smith	oh, OK
14:50	llasram	joobus: Are you passing `slurp` the URL for a page, or something you opened yourself via e.g. `clojure.java.io/reader` ?
14:50	joobus	(slurp "http://zerohedge.com")
14:50	justin_smith	llasram: oh, good point, I don't even think about that usage
14:50	llasram	justin_smith: But you were apparently correct anyway :-)
14:50	joobus	sometimes it comes back with messed up output, like the charset was wrong or something
14:51	ben_vulpes	I'm using peridot to test some forms with file uploads - does anyone know how to use the peridot (request "/upload" :request-method :post :params {:some "values" :file (file "resources/myfile.txt")) in such a way that it posts all the values in addition to the multipart file? or am i missing something important in how multipart uploads works?
14:51	justin_smith	joobus: sounds like a problem on their end to me, maybe they are load balancing and some of their servers are sending bad content encoding headers
14:51	ben_vulpes	hm i guess if i use a map keyword other than "file" all the headers come through
14:52	joobus	yeah, that sounds reasonably accurate
14:52	justin_smith	joobus: you could try putting the string into a byte-array, then coercing it back to string with various encoding arguments
14:53	joobus	tbh, i don't particularly care about that site, i was just testing out slurp
14:53	justin_smith	&(-> "snowman ☃" .getBytes (String. "UTF-8"))
14:53	lazybot	⇒ "snowman ☃"
14:53	justin_smith	&(-> "snowman ☃" .getBytes (String. "UTF-16"))
14:53	lazybot	⇒ "獮潷浡渠�"
15:06	ricky____	I'm going through the unless macro example from Clojure in Action and wondering why when unless is a function, the 'then' portion of the 'if' doesn't get evaluated twice when it's true.
15:07	ricky____	If it's easier to understand this as code, why does (exhibits-oddity? 7) not show 'Very odd, indeed!' twice? @ http://pastebin.com/JfbjW4QT
15:07	justin_smith	ricky____: then is fully evaluated before the function even sees it
15:08	justin_smith	unless only sees the fully evaluated form - the printing happens before unless even runs
15:08	ricky____	So what does unless actually see as its second argument?
15:09	justin_smith	the return value of the form provided as a second arg
15:09	ricky____	So since it's println, it gets nil?
15:09	justin_smith	in exhibits-oddity? the value is nil
15:09	justin_smith	yes
15:11	justin_smith	,(letfn [(unless [test then] (println "in unless") (if (not test) (do then (println "unless done"))))] (unless (even? 1) (println "arg to unless")))
15:11	clojurebot	arg to unless\nin unless\nunless done\n
15:11	justin_smith	that should make it clear
15:15	bcm	does anyone here use emacs with add-on packages?
15:15	bcm	www.elgethub.com
15:17	thesaskwatch	Hi .. is there some simpler / idiomatic mechanism for pub-sub pattern than atom and adding watches to it?
15:18	justin_smith	thesaskwatch: you can do pub-sub nicely with core.async
15:18	justin_smith	http://yobriefca.se/blog/2014/06/04/publish-and-subscribe-with-core-dot-asyncs-pub-and-sub/
15:19	thesaskwatch	justin_smith: ok, but my use case uses blocking i/o
15:22	justin_smith	thesaskwatch: what about blocking from outside the go block, and sending to a channel when the io completes?
15:22	justin_smith	or doing a blocking read from outside a go block, before a blocking write outside a go block, for that matter
15:23	thesaskwatch	justin_smith: I'm not sure how all those mechanisms are gonna work together. I'm wring an irc client. I'd like to be able to start it and send/receive messages asyncronously (which is a hint for core.async, true).
15:24	justin_smith	thesaskwatch: all that said, there is pubsub via 0mq http://zguide.zeromq.org/clj:psenvsub
15:24	thesaskwatch	justin_smith: so I guess I could start a thread within this client and return two channels
15:24	thesaskwatch	wring -> writing
15:25	justin_smith	so, if you want to send / receive messages, what about having a go block doing pub sub with an input channel and output channel, then writing to the input and reading the output from your other threads?
15:25	schmee	thesaskwatch: I'm doing a client server thing as well, I have a thread that just reads things of the socket and push them onto a channel
15:25	justin_smith	all the IO can be on the outside of the go block
15:25	schmee	then all the other communication happens over channels
15:26	justin_smith	schmee: yeah, what thesaskwatch needs sounds like that plus a third thread that writes out to the TCP connection again
15:27	thesaskwatch	I actually don't mind using a real thread, there will be no many connections
15:27	milos_cohagen	thesaskwatch: i wrote a wrapper for netty and core async https://github.com/marsmining/nettyca it's an example for simple tcp server
15:27	thesaskwatch	milos_cohagen: thanks, I'll take a look
15:27	schmee	justin_smith: yep, that's how I'm doing it now
15:28	milos_cohagen	thesaskwatch: maybe you could write the client code :)
15:28	schmee	thesaskwatch: it seems to work pretty well, although I have no experience whatsoever in writing servers
15:28	thesaskwatch	milos_cohagen: yeah, I have to wrap my head around it first :)
15:29	thesaskwatch	schmee: could you share the code with me?
15:30	thesaskwatch	schmee: or is it proprietary?
15:33	phuu	hey #clojure. core.async question. why does alts! get priority if I <! then alts! in separate go blocks? gist here https://gist.github.com/phuu/32ab6737141d989ea280
15:34	phuu	given (def c (chan)) and (def c2 (chan))
15:34	dnolen_	phuu: it doesn't get priority, you should assume the behavior is non-deterministic
15:37	phuu	dnolen_: ah, ok. i must have just got the same result a few times in a row.
15:38	phuu	dnolen_: is this true of multiple takes? if i <! 3 times then >!, is the choice also non-deterministic?
15:39	dnolen_	phuu: yes
15:39	phuu	Ahha!
15:39	phuu	right. well, i got my JS channel implementation wrong then
15:39	milos_cohagen	phuu: assuming the takes are each in their wn go block
15:40	milos_cohagen	*own
15:40	phuu	milos_cohagen: right
15:45	phuu	ok, thanks both
16:29	SagiCZ1	any easy way to destructure map within map?
16:30	SagiCZ1	(let [<desctructuring> {:a {:x 0 :y 2} :b 3}] ... get 0 and 2 ..
16:31	llasram	SagiCZ1: yeah -- destructuring nests
16:31	xeqi	,(let [{:a {:keys [x y]}} {:a {:x 0 :y 2} :b 3}] [x y])
16:31	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: x in this context, compiling:(NO_SOURCE_PATH:0:0)>
16:32	llasram	,(let [{{:keys [x y]} :a} {:a {:x 0 :y 2} :b 3}] [x y])
16:32	clojurebot	[0 2]
16:32	xeqi	bah
16:32	Bronsa	heh
16:32	llasram	zoom
16:33	SagiCZ1	ok.. i thought it was possible.. thank you guys
16:33	Bronsa	TBH I Never use "multiple levels" destructuring, it gets kinda noisy IMHO
16:34	xeqi	agreed, I usually just make another binding in the let
16:40	SagiCZ1	why does this not work?
16:40	SagiCZ1	,(apply String. "hello" ["world" "!"])
16:40	clojurebot	#<CompilerException java.lang.ClassNotFoundException: String., compiling:(NO_SOURCE_PATH:0:0)>
16:40	SagiCZ1	cant apply on constructors?
16:40	SagiCZ1	could the exception get any more stupid?
16:41	xeqi	"error"
16:42	SagiCZ1	yeah.. but seriously class not found? how did it even get to THAT
16:42	hyPiRion	SagiCZ1: String. is not a class
16:43	hyPiRion	(String. ..) is syntactic sugar for (new String ..)
16:44	hyPiRion	,(macroexpand '(String. "foo"))
16:44	clojurebot	(new String "foo")
16:44	hyPiRion	,(macroexpand '(apply String. "foo" ["bar" "baz"]))
16:44	clojurebot	(apply String. "foo" ["bar" "baz"])
16:44	SagiCZ1	,(apply (partial new String) "hello" ["world" "!"])
16:44	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: new in this context, compiling:(NO_SOURCE_PATH:0:0)>
16:45	hyPiRion	and new is a macro, heh.
16:45	SagiCZ1	>:C
16:45	llasram	SagiCZ1: Unfortunately you can only `apply` functions, and there's nothing built into Clojure for turning constructors into functions
16:45	SagiCZ1	,(macroexpand '(new String "foo))
16:45	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading string>
16:45	SagiCZ1	,(macroexpand '(new String "foo)))
16:45	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading string>
16:46	hyPiRion	forgot a "
16:46	SagiCZ1	,(macroexpand '(new String "foo"))
16:46	clojurebot	(new String "foo")
16:46	SagiCZ1	wat
16:46	SagiCZ1	is it a special macro then?
16:46	hyPiRion	yes. it's a core macro.
16:47	hyPiRion	It's probably better to call it a special form (?)
16:47	SagiCZ1	mmkay.. no apply for me then..
16:47	SagiCZ1	well i could wrap the constructor in a function if i wanted
16:54	ben_vulpes	has anyone ever seen wrap-multipart-params fail to do the expected tempfile behavior?
16:57	blaenk	I'm wondering if I create an uberjar out of my program, how can I handle (can I?) external configuration files? so preferably I'd like for a configuration file to be along-side the jar file, not within it, so that it can easily be edited
16:59	ben_vulpes	blaenk: i uberjar my apps and launch them in docker containers with environment variables
16:59	blaenk	cool
16:59	ben_vulpes	course, that entails all sorts of other overhead in deploy...
17:00	xeqi	ben_vulpes: expected tempfile behavior? I've had problems when I attempted to read it twice
17:02	ben_vulpes	xeqi: i'm failing to even get wrap-multipart-params to write the file to disk instead of reading it in as a...string?
17:03	mi6x3m	if x is a function returning a function
17:03	mi6x3m	is there a saner way to call the result than ((x)) ?
17:03	ben_vulpes	in the "file" paramter in :multipart-params, i'm just getting a string and in the body of the request I'm getting a buffered input stream.
17:03	ben_vulpes	mi6x3m: what's insane about ((x))?
17:04	mi6x3m	dunno, looks kinda funny
17:05	ben_vulpes	dem parens
17:05	lodin	mi6x3m, I guess you could do (apply (x) [...]), but I would hesitate to call that saner.
17:05	catern	(trampoline x)
17:05	catern	(please don't)
17:06	jjido	catern: hey, I like trampoline ;)
17:06	catern	jjido: i do too :)
17:06	jjido	catern: for trampoline work though
17:06	catern	but i was just joking, please don't use it for this
17:07	catern	unles you're
17:07	catern	trampolining an algorithm
17:07	catern	in which case, do use it
17:08	lodin	Particularly, don't use it if ((x)) can return a function.
17:10	lodin	Is there any function f such that (into (empty x) (f x)) is the same as x, other than #(into (empty %) %)?
17:12	catern	id
17:13	catern	er, identity
17:13	lodin	catern, identity fails for lists.
17:14	catern	`(into (empty '(42)) (identity '(42)))
17:14	catern	er
17:14	catern	,(into (empty '(42)) (identity '(42)))
17:14	clojurebot	(42)
17:15	lodin	,(let [f identity x '(1 2 3)] (into (empty x) (f x)))
17:15	clojurebot	(3 2 1)
17:15	catern	oh, right
17:16	gfredericks	lodin: so your #(into (empty %) %) works because it reverses a list twice?
17:16	lodin	gfredericks: right.
17:16	lodin	gfredericks: Not a very nice solution.
17:16	gfredericks	lodin: why on earth do you need such a thing?
17:17	lodin	gfredericks: Makes it easier to deal with mixed seqables when the return type is important.
17:18	llasram	lodin: If the return type is important, your function should return an instance of the correct type
17:19	llasram	lodin: I can't think of a situation where I've needed a function which took either a list or lazy seq or a vector and was guaranteed to returned an instance of the same type
17:20	bcm	hi clj-learner
17:20	amalloy	llasram: well, conj
17:20	clj-learner	hi
17:20	llasram	amalloy: pfft, fine :-p
17:20	llasram	But just `conj`
17:21	gfredericks	also into
17:21	lodin	llasram: Right, and into uses conj.
17:21	gfredericks	and intos uses into and multi-intos uses intos
17:29	hyPiRion	Where's fmap when we need it
17:29	lodin	llasram, Consider (defn map-generic [f x] (into (empty x) (map f (into (empty x) (seq x)))))
17:30	lodin	then (= (map-generic inc [1 2 3]) [2 3 4]) and (= (map-generic inc #{1 2 3}) #{2 3 4}) and (= (map-generic #(update-in % [1] inc) {:a 1 :b 2 :c 3}) {:a 2 :b 3 :c 4})
17:31	llasram	lodin: I honestly have difficulty imagining wanting that :-)
17:31	hyPiRion	lodin: huh, I'm not sure the last example is correct
17:32	hyPiRion	I think you want (fn [[k v]] [k (inc v)]) instead of that anonymous function
17:33	gfredericks	,(defn applicate [& fs] (fn [& vals] (mapv #(%1 %2) fs vals)))
17:33	clojurebot	#'sandbox/applicate
17:33	gfredericks	,((applicate identity inc) [:foo 41])
17:33	clojurebot	[[:foo 41]]
17:33	gfredericks	oh right
17:33	lodin	,(defn map-generic [f x] (into (empty x) (map f (into (empty x) (seq x)))))
17:33	clojurebot	#'sandbox/map-generic
17:33	hyPiRion	lodin: however, have you looked at fluokitten? it provides an fmap function
17:33	lodin	(= (map-generic #(update-in % [1] inc) {:a 1 :b 2 :c 3}) {:a 2 :b 3 :c 4})
17:34	lodin	,(= (map-generic #(update-in % [1] inc) {:a 1 :b 2 :c 3}) {:a 2 :b 3 :c 4})
17:34	clojurebot	true
17:34	hyPiRion	lodin: ohh
17:37	zwer	llasram the idea is that the caller picked an approriate sequence type, and that the function that is processing it generically shouldn't change it
17:39	llasram	zwer: Sure, I get the idea. I just disagree that it is (very often) useful
17:44	lodin	llasram: I figured (empty x) and (conj) is for situations when you want to deal more generally with a collection.
17:54	SagiCZ1	hi.. how do i get the first element from seq of maps that has 0 as a value of :number? [{:number 6 :a 0} {:number 0 :a 3}] --->{:number 0 :a 3}
17:55	llasram	SagiCZ1: (first (filter (comp zero? :number) ...))
17:56	luqi	SagiCZ1: also you can use some
17:57	luqi	(some (comp zero? :number))
17:57	amalloy	luqi: try that; it won't work
17:58	SagiCZ1	yeah comp will be handy
17:58	gfredericks	clojurebot: amalloy is <reply> try that; it won't work
17:58	clojurebot	'Sea, mhuise.
17:59	luqi	hmm, I see.
18:00	luqi	my bad. some won't work
18:11	martinklepsch	(def xform (comp (map fetch-data) (map munge-data)))
18:11	martinklepsch	is that something transformers are meant for?
18:13	martinklepsch	I have a fn that I want to map over a seq that has side effects and I'm not sure how to do that or if it's the right thing at all
18:14	justin_smith	martinklepsch: do you want both the side effects and the results?
18:17	martinklepsch	justin_smith: yes. I'm trying to implement some sort of pipeline: channel-in > fetch-data > do something with data > return result of last function in pipeline
18:19	martinklepsch	I was initially thinking about using map< for that but now I'm not even sure if that would have been the right approach
18:25	justin_smith	reduce is eager, and you can build up your result either element by element or by accumulating a total, whichever is apropriate
18:28	martinklepsch	justin_smith: so in my case element by element is what I want, right? do you think the scenario I described makes sense for using transducers?
18:29	justin_smith	it really does (from what I have seen - have not used transducers yet myself, but this looks right for them)
18:46	martinklepsch	justin_smith: ok, thats reassuring enough to keep digging :)
18:46	martinklepsch	thanks
18:56	martinklepsch	justin_smith: pipeline-async looks exactly like what I'm trying to do: https://github.com/clojure/core.async/blob/e7de6747e5d90e08fb9d6d6dbe41c2bdd1ef00a0/src/main/clojure/clojure/core/async.clj#L523
19:57	lavokad	why :keys can only be bind to symbols which the same names as the keys?
19:57	amalloy	lavokad: :keys is shorthand for doing exactly that; if you want to give explicit names, use the longhand map-destructuring form
19:58	amalloy	,(let [m {:xpos 1, :ypos 2}, {x :xpos, y :ypos} m] [x y])
19:58	clojurebot	[1 2]
21:00	zanes	Is there a built-in function that takes a seq and returns the same seq with repeating values removed?
21:00	zanes	I feel like this exists, but I can’t find it.
21:01	tac_	like a uniq?
21:02	zanes	For example, (non-repeating [1 1 1 2 3 3 1]) ; => (1 2 3 1)
21:02	zanes	It’s pretty simple to write.
21:03	amalloy	&(doc distinct)
21:03	lazybot	⇒ "([coll]); Returns a lazy sequence of the elements of coll with duplicates removed"
21:03	amalloy	oh, but you want to remove only consecutive duplicates
21:04	amalloy	&(map first (partition-by identity [1 1 1 2 3 3 1]))
21:04	lazybot	⇒ (1 2 3 1)
21:06	zanes	amalloy: So, I tried that, but I’m in a situation where the second value of the lazy sequence being consumed may take a while.
21:06	zanes	I’d love for the first value to be realized immediately, rather than only after a change happens.
21:06	zanes	Does that follow?
21:06	amalloy	sure. you have to write that yourself, but it's not hard
21:06	zanes	Okay, great.
21:07	Ifiht	'(def s "lorem ipsum datum")
21:08	Ifiht	'(def s "lorem\u000A ipsum\u000A datum\u000A")
21:08	Ifiht	'(println s)
21:09	Ifiht	oh darn, no clojurebot.
21:10	justin_smith	,"Hello Ifiht"
21:10	clojurebot	"Hello Ifiht"
21:10	Ifiht	,8
21:10	clojurebot	8
21:10	Ifiht	,"Thanks justin"
21:10	clojurebot	"Thanks justin"
21:11	Ifiht	,(def s "lorem\u000A ipsum\u000A datum\u000A")
21:11	clojurebot	#'sandbox/s
21:11	Ifiht	,(println s)
21:11	clojurebot	lorem\n ipsum\n datum\n\n
21:11	Ifiht	,(def s "lorem ipsum\u000A datum\u000A")
21:11	clojurebot	#'sandbox/s
21:11	Ifiht	,(def s "lorem\u000A ipsum\u000A datum\u000A")
21:11	clojurebot	#'sandbox/s
21:12	zanes	amalloy: Something like this? https://gist.github.com/zane/33a5b77162441ec3a25e
21:12	Ifiht	,(def s (split s #"\u000A"))
21:12	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: split in this context, compiling:(NO_SOURCE_PATH:0:0)>
21:12	Ifiht	,(def s (clojure.string/split s #"\u000A"))
21:12	clojurebot	#'sandbox/s
21:12	Ifiht	,(def s (sort s))
21:12	clojurebot	#'sandbox/s
21:13	justin_smith	Ifiht: does \u work the same way in regexes?
21:13	Ifiht	It does in my code, let's see
21:13	Ifiht	,(print s)
21:13	clojurebot	( datum ipsum lorem)
21:14	justin_smith	it would sort weird because of the the leading spaces though
21:14	Ifiht	yes
21:14	Ifiht	(def s (clojure.string/trim-whitespace s))
21:14	Ifiht	,(def s (clojure.string/trim-whitespace s))
21:14	clojurebot	#<CompilerException java.lang.RuntimeException: No such var: clojure.string/trim-whitespace, compiling:(NO_SOURCE_PATH:0:0)>
21:15	Ifiht	,(def s (clojure.string/trim s))
21:15	clojurebot	#<CompilerException java.lang.ClassCastException: clojure.lang.ArraySeq cannot be cast to java.lang.CharSequence, compiling:(NO_SOURCE_FILE:0:0)>
21:15	amalloy	zanes: yes, that's a fine implementation. i would make a few changes: (1) "last" is a pretty confusing name; i'd call it "prev". (2) i would start each arity with (lazy-seq ...) instead of putting it in the middle; (3) you should use when-first instead of when-let/first (especially because your implementation is broken for seqs containing nil or false)
21:15	zanes	Great feedback. Thanks!
21:15	Ifiht	,(def s "lorem ipsum datum")
21:15	clojurebot	#'sandbox/s
21:16	Ifiht	,(def s (clojure.string/split s #"\u0020"))
21:16	clojurebot	#'sandbox/s
21:16	Ifiht	,(print s)
21:16	zanes	Is it always more idiomatic to start each arity with lazy-seq?
21:16	clojurebot	[lorem ipsum datum]
21:16	Ifiht	got it
21:16	amalloy	zanes: there are probably some exceptions, but none spring to mind
21:17	Ifiht	,(def s (join (str "(latin)" \u000A) s))
21:17	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: join in this context, compiling:(NO_SOURCE_PATH:0:0)>
21:18	justin_smith	Ifiht: you can send messages to clojurebot
21:18	justin_smith	Ifiht: unless there is something you are trying to show all of us
21:18	justin_smith	or even run your own repl locally
21:18	Ifiht	yes, I have it working locally, but clojurebot doesn't have my code, one step left?
21:19	Ifiht	,(def s (clojure.string/join (str "(latin)" \u000A) s))
21:19	clojurebot	#'sandbox/s
21:19	Ifiht	YES
21:19	Ifiht	,(println s)
21:19	clojurebot	lorem(latin)\nipsum(latin)\ndatum\n
21:19	Ifiht	THERE!!! ^
21:19	Ifiht	can anyone tell me why join skips the last item?
21:20	justin_smith	it only goes between items
21:21	amalloy	Ifiht: also instead of writing a million separate lines with def, collapse it all into one form with let
21:22	Ifiht	would let still work if I want to use the same identifier?
21:23	justin_smith	you can repeat ids in let
21:23	llasram	,(let [s 1, s (inc s)] s)
21:23	clojurebot	2
21:23	justin_smith	,(let [s "a" s (str s "b") s (str s "c")] s)
21:23	clojurebot	"abc"
21:24	Ifiht	Thanks justin, amalloy. I'll do that.
21:26	bounb	do you clojure-heads have the feeling you could never go back to your C++/Java days
21:27	justin_smith	bounb: horses for courses
21:27	justin_smith	there are certain things I would never do in c++/java, other things I would never do in clojure
21:28	justin_smith	though personally for lower level stuff I would skip straight from c to java and not touch c++ if it was purely up to me
21:28	bounb	hm so it's philosophy does not revolutionize they way you approach programming
21:28	justin_smith	oh it does
21:28	justin_smith	but there are some things clojure will never be good at
21:28	justin_smith	but the set of things c will never be good at is larger
21:30	bounb	"never" meaning "due to some actually existing irreparable theoretical shortcoming"?
21:30	justin_smith	bounb: for example there are certain tasks in clojure where even (especially) an experienced clojure dev will tell you you are better off writing some java code rather than trying to do that task in pure clojure
21:31	justin_smith	bounb: heap allocated persistent data structures are bad for realtime, and are not cache-line friendly
21:31	justin_smith	for example
21:31	bounb	wow ok
21:31	bounb	my bubble is slightly deflated
21:32	justin_smith	also, clojure has to be able to redefine certain things at runtim - which is terrible for your heap usage - it won't really fit in embedded
21:32	bounb	aha
21:32	justin_smith	all that said, clojure is awesome - it isn't perfect for all tasks though
21:32	zanes	amalloy: Out of curiosity, how would you do it without multiple arities?
21:32	bounb	so you have to make considerations of hardware to find the negatives?
21:33	bounb	that doesn't bother me. storage/computation is bigger and faster day by day
21:33	amalloy	zanes: (defn whatever [xs] ((fn [xs prev] (lazy-seq ...)) (rest xs) (first xs)))
21:33	zanes	Ah, okay.
21:34	justin_smith	bounb: it's more like knowing what your limitations are - if your requirements include low ram usage, fast startup time, low gc churn, or cache friendliness / low latency, than clojure is likely not a good fit. But much of programming does not have these limitations.
21:34	amalloy	and that is actually how i would write it: i generally prefer helper lambdas over multiple arities. but i don't think it's important enough to suggest it as a critique
21:34	zanes	Cool. Thanks!
21:34	bounb	justin_smith: well said. thanks
21:35	justin_smith	np
21:35	bounb	i'm just a smitten newbie
21:35	bounb	watched several hours of hickey talks in the past couple days
21:36	justin_smith	cool, he is a good speaker
21:36	bounb	yeah absolutely
21:36	bounb	which other speakers in the programming/comp sci world are on his level
21:38	justin_smith	I saw a Rob Pike speak once, he was pretty good
21:38	bounb	i see him almost like a prophet, a visionary the way he speaks (ok sounds a bit sycophantic but honestly)
21:38	bounb	yeah! i like rob pike too
21:38	bounb	seen a couple great talks from him on go/concurrency
21:40	bounb	hickey is basically showing me everything i thought i knew about programming is wrong
21:41	bounb	it can be really simple
21:42	zanes	amalloy: That’ll drop the first value, no?
21:42	amalloy	zanes: yes, you need to be more careful than i was; i just wanted to show you the structure of the helper-function skeleton
21:46	zanes	bounb: Maybe Joe Armstrong?
21:46	bounb	thanks!
21:53	bounb	justin_smith: related question then. does your job impose those limitations - if not, do you use clojure at work?
21:53	justin_smith	bounb: yup, I do backend for web stuff, and use clojure
21:54	justin_smith	and I love it
21:54	justin_smith	(inc clojure)
21:54	lazybot	⇒ 19
21:54	bounb	ah that is good to hear
21:54	bounb	(inc clojure)
21:54	lazybot	⇒ 20
21:54	bounb	is this like a karma system
21:54	justin_smith	$karma clojure
21:54	lazybot	clojure has karma 20.
21:54	justin_smith	indeed it is :)
21:55	justin_smith	it looks like clojure code, but really it is just a command for the bot
22:00	bounb	(repeatedly (partial inc bounb))
22:00	bounb	am i doing it right?!
22:00	justin_smith	it's just a pseudo-syntax
22:00	justin_smith	also, the partial wouldn't execute
22:01	justin_smith	,(repeatedly (partial + 1))
22:01	clojurebot	(1 1 1 1 1 ...)
22:01	bounb	disappointed :(
22:01	justin_smith	or wait, yeah it would
22:01	justin_smith	d'oh
22:01	bounb	B)
22:01	bounb	(tbh i tested it first)
22:01	bounb	(inc bounb)
22:01	lazybot	You can't adjust your own karma.
22:02	bounb	foiled!
22:04	iamdustan	I’m just starting to learn clojure so decided to do some codeeval challenges with it
22:04	iamdustan	but I am always blowing the memory constraints of codeeval
22:04	iamdustan	anyone else experience this?
22:05	justin_smith	if they have ram limits, that's gonna be rough on clojure
22:05	tac_	iamdustan: what are codeeval challenges?
22:05	justin_smith	https://www.codeeval.com/
22:05	iamdustan	e.g. simple sorting. my memory usage is 65413120 bytes
22:05	bounb	the copy on that site is funny
22:06	tac_	iamdustan: are you using recursion?
22:06	bounb	"unlock exclusive hacker deals"
22:06	justin_smith	iamdustan: yeah, clojure needs to load the whole language into memory at runtime (though arrdem tried to change that - but it looks like that will become a different language)
22:06	iamdustan	with this code: https://gist.github.com/iamdustan/83d8f3c8759e31eb0f74
22:07	iamdustan	bounb: haha yeah let’s pretend it doesn’t say that
22:07	iamdustan	tac_: I don’t believe I am
22:07	justin_smith	iamdustan: what's with the redundant vec call on line 7?
22:07	iamdustan	bounb: the design of that site is just as bad as the copy.
22:07	iamdustan	justin_smith: oh nice. I didn’t even realize I had done that when I added the map
22:08	bounb	yeah it's so cheesy
22:08	bounb	"Incredible profile pages that allow you to show the info you want while protecting your privacy."
22:08	justin_smith	iamdustan: that will help with ram a little - but the main factor unless your task is huge is going to be the huge resident size of clojure itself
22:08	bounb	WOW what a great feature so generous
22:09	bounb	sorry i'm not helping you
22:09	iamdustan	bounb: you are adding to my nightly entertainment :)
22:10	bounb	haha good
22:10	iamdustan	I realized why I have no stackoverflow answers for anything...all the attempted answers I’ve begun to write were troll-ish in nature.
22:10	bounb	i can't wait to redeem an Exclusive Hacker Deal IRL!
22:11	iamdustan	justin_smith: thanks a lot. Good to know that even though clojure is “supported” it’s not possible to pass their requirements.
22:11	iamdustan	bounb: http://cl.ly/image/1c0q0p2n3W0s
22:12	bounb	LOL
22:12	justin_smith	iamdustan: you could suggest they look at the baseline size mem usage wise of "lein repl", and only count usage past that, but it seems like that would require reworking their whole deal
22:12	iamdustan	We recommend everything
22:12	bounb	they so keen to sell yr info to other companies
22:12	bounb	"Not recommended"
22:12	iamdustan	oh yeah. the “actually” private one
22:12	bounb	because then we can't monetize you
22:13	iamdustan	justin_smith: good idea. it’d be nice to at least see my own success progress through these.
22:13	dbasch	iamdustan: https://getsatisfaction.com/codeeval/topics/clojure_time_memory_stats_seem_wrong
22:15	iamdustan	dbasch: I just started reading that same thread
22:15	iamdustan	from 2013 so you’d think something would be fixed by now
22:17	iamdustan	and that thread proves justin_smith correct
22:17	justin_smith	also, regarding the comment on that page that "clojure needs the whole jvm" - the jvm is lazily loaded to some degree, the real bottleneck is that it needs the whole of clojure compiled and in memory at runtime
22:18	andrewchambers	dnolen_: I found the thing I was talking about before http://bddbddb.sourceforge.net/ . I don't know if its the sort of thing you are interested, datalog, binary decision diagrams and program anaylsis.
22:18	dnolen_	andrewchambers: I'm aware of it :)
22:18	bounb	pop poll: who here is not a linux user
22:18	justin_smith	iamdustan: and that's the nature of clojure - they are just measuring things in a way that is not friendly to this language
22:18	andrewchambers	cool :)
22:18	catern	bounb: are you a Linux user?
22:18	bounb	no comment
22:19	catern	i see
22:19	catern	you are interested in switching
22:19	catern	well do so
22:19	andrewchambers	I liked the part where they said pointer anaylsis was 10 times less code and ran a bit faster in datalog
22:20	catern	it saves so much effort in the long run
22:20	zanes	Is there a reason why clojure.core functions like distinct don’t have a 0-arity version that returns a transducer?
22:21	justin_smith	catern: as a linux user of 15+ years now, I'll have to say it can also be a huge pain in the ass. But if you don't play flashy games or do graphic design work and you like good command line tools, it's great.
22:21	bounb	catern: nah, i am a fairly long time user. just wanting to confirm my suspicion that this community is pretty much a subset of the community of linux users
22:21	iamdustan	justin_smith: thanks for the help.
22:21	justin_smith	iamdustan: np, too bad about how they are scoring our favorite language
22:22	bounb	justin_smith: well said again about linux
22:22	catern	bounb: oh okay. well in that case, no, there's probably a lot of OS X users around, judging by today's sad trends
22:22	bounb	we don't really have any good OSs
22:22	bounb	they're all a bit naff in various ways
22:23	justin_smith	just by observation I would say that OS usage in the clojure community is in order: osx, linux, windows
22:23	bounb	oh i see
22:23	bounb	yes i forget just how big apple is these days
22:23	justin_smith	that's really informal :)
22:23	bounb	justin_smith: don't worry. it was a "pop poll"
22:24	bounb	im not writing a scientific study
22:24	justin_smith	and I'd say in terms of convenience of developing clojure, the ranking is linux, osx, windows
22:25	justin_smith	but that's even more subjective
22:26	zanes	amalloy: I guess the most succinct implementation is (partial sequence (comp (partition-by identity) (map first))). Heh.
22:27	zanes	Or maybe that would have the same problem of delaying the first value. Hm.
22:27	iamdustan	justin_smith: ha. That’s a bit of a stretch for me yet. I still will claim javascript as my fave, but I’m excited about clojurescript and om.
22:28	blaenk	anyone use cljsbuild? I have it in my :hooks and it keeps saying Compiling ClojureScript whenever I run lein repl lol
22:28	blaenk	thought it was only supposed to run when other things were run, such as compile and clean
22:28	amalloy	zanes: probably does, yeah
22:30	bounb	iamdustan: javascript is your favourite language?
22:31	iamdustan	bounb: guilty
22:31	andrewchambers	iamdustan: what languages have you used?
22:31	iamdustan	bounb: though that is not for breadth of experience
22:31	bounb	...explain?
22:31	iamdustan	oh goodness
22:31	iamdustan	personal history.
22:31	andrewchambers	javascript is pretty average overall
22:32	andrewchambers	not super bad
22:32	andrewchambers	not great
22:32	iamdustan	I’ve been a developer for ~3 years (that I’ll count at least)
22:32	andrewchambers	You code webstuff only though right?
22:32	iamdustan	and that is all as a front end dev
22:32	zanes	Man, writing transducers by hand is weird.
22:32	andrewchambers	I think you just like javascript because you are comfortable iwth it
22:32	iamdustan	and I went to were I work now to learn back end dev
22:33	andrewchambers	I think typescript is decent
22:33	iamdustan	but they realized how good I was at front end and I got pigeon-holed so I just followed the rabbit trail down
22:33	bounb	anyone here not primarily a "programmer" in their day job?
22:33	dbasch	bounb: you’re assuming everyone here has a day job
22:33	andrewchambers	Software engineer might still be a programmer :)
22:33	iamdustan	I’ve done a bit in python, ruby, read a haskell book, started SICP (since I’m self-taught) which got me into lisps, and then because of Om I shifted to clojure
22:34	bounb	bounb: if you don't then your answer is implicitly "no" and you don't need mention it
22:34	iamdustan	I read most of a C++ book last year, but that was still biased towards web development (browser engines)
22:34	bounb	uh fuck i addressed myself
22:34	bounb	dbasch: ^
22:34	iamdustan	haha
22:34	bounb	<- moron
22:34	iamdustan	long-winded way to say, yeah I am a web developer through and through
22:35	andrewchambers	yeah, javascript is decent compared to those. Haskell is just way out there, and just reading doesn't give you the proper feel for it.
22:35	andrewchambers	you don't really have any typed languages :P
22:36	iamdustan	true, true. To that point: I have played with typescript and C#
22:36	andrewchambers	but thats ok for what you seem to workon
22:36	iamdustan	well, C++ no?
22:36	andrewchambers	i dunno
22:36	andrewchambers	C++ is horrible
22:36	andrewchambers	But at least with C and C++ you will learn more fundamental computer science stuff
22:36	andrewchambers	since its much lower level
22:37	iamdustan	I have a (former) coworker who is big into haskell and I read the “...for great good” book and finished and was like “that was really interesting and I have no idea how I could solve anything with it if my life depended on it”
22:37	iamdustan	I did write a couple lines of C for a project actually :)
22:37	iamdustan	well, modified.
22:37	andrewchambers	yeah, i dunno clojure is pretty high level and cool once you are used to it
22:38	andrewchambers	clojurescript is alot better than javascript imo, but thats just an opinion
22:38	andrewchambers	Javascript is quite verbose and the callbacks get very nested
22:38	dbasch	andrewchambers: it depends on what you mean by “fundamental cs stuff.” You do get closer to hardware, but that’s not necessarily what cs is about
22:38	andrewchambers	dbasch: yeah, you are right
22:38	bounb	how can you compare clojurescript and javascript?
22:38	andrewchambers	closer to computer stuff
22:39	andrewchambers	not algorithms or anything
22:39	andrewchambers	but understanding hardware etc
22:39	iamdustan	it’s like java to javascript. They both have common parts in the name!
22:39	bounb	hah
22:39	andrewchambers	I dunno, clojurescript has its own problems
22:39	andrewchambers	like way harder for abeginner to get started
22:39	andrewchambers	more setup
22:40	andrewchambers	they aren't problems with the language, but they are real problems.
22:40	iamdustan	like everything with java :)
22:40	andrewchambers	To code in clojurescript you need to understand all the javascript stuff AND all the clojurescript stuff
22:40	andrewchambers	so its not really beginner friendly
22:40	bounb	correct me if i'm wrong but i thought clojurescript was just a clojure->javascript compiler
22:40	andrewchambers	same with clojure<->java
22:40	iamdustan	I installed maven for a quick freelance project the other day and immediately lost all faith in the java world.
22:41	andrewchambers	java is horrible
22:41	andrewchambers	i dunno, The only language that has tools I enjoy is Go at the momeny
22:41	andrewchambers	little setup, just works
22:41	bounb	why not clojure
22:41	andrewchambers	clojure is freaking hard to get started with
22:41	andrewchambers	stuff is outdated
22:42	andrewchambers	the lein project.clj stuff took me ages to get started with
22:42	andrewchambers	because the templates i was copying were out of date
22:42	bounb	hmmmmmm
22:42	andrewchambers	then my laptop was really slow
22:42	andrewchambers	lein version took 6 seconds
22:42	bounb	so complaints about the language ecosystem
22:42	andrewchambers	to print
22:42	andrewchambers	but i understand that
22:43	andrewchambers	To use clojure, you need to know java and clojure and the tools
22:43	justin_smith	andrewchambers: I got pretty far with clojure before I learned any java
22:43	justin_smith	andrewchambers: though I did have to figure out just enough to read some javadoc
22:44	andrewchambers	Yeah, but if you don't understand java exceptions or you don't understand what a classpath is
22:44	andrewchambers	you are screwed
22:44	andrewchambers	someone with experience can easily work it out
22:44	andrewchambers	but if you are totally new then its harder
22:44	bounb	andrewchambers: good to hear that point of view. thx
22:44	andrewchambers	I mean, 4clojure is decent
22:44	dbasch	andrewchambers: that’s more jvm stuff than java proper
22:44	andrewchambers	since it lets you play with no setup
22:45	justin_smith	(inc dbasch)
22:45	lazybot	⇒ 9
22:45	blaenk	anyone know how to generate a certain length random string? I found crypto-random which lets me specifies the size in bytes the size then increases when its encoded in base64 or whatever
22:45	justin_smith	yeah, you need to learn the tooling / ecosystem, but not so much the language (until you decide to go deeper)
22:45	blaenk	I mean, short of truncating the string
22:46	andrewchambers	The clojure language itself is pretty easy.
22:46	andrewchambers	My one complaint was the using and ns :refer
22:46	andrewchambers	so many ways to include stuff
22:46	justin_smith	blaenk: like cryptographically secure random string?
22:46	andrewchambers	not really explained well anywhere
22:46	blaenk	yep
22:46	blaenk	to use for ring's cookie key
22:46	dbasch	blaenk: what characters do you want to use / exclude?
22:46	blaenk	I'd just like something that's printable, i.e. no unprintable characters
22:46	dbasch	blaenk: use java uuid
22:47	andrewchambers	all that being said, i think clojure is great once you know how to use it
22:47	blaenk	uuids can be 16 characters long? I don't know the implications of truncating something
22:47	brehaut	tautology is tautological
22:48	iamdustan	what are some use cases that you folks are using clojure for?
22:48	avi__	testing java libraries
22:48	iamdustan	My viewpoint is entirely too focused on the web platform in any fashion
22:49	justin_smith	iamdustan: backend for http
22:49	avi__	I use clojure's repl to test out Jars and explore them before I have to write a lot of java code.
22:49	iamdustan	avi__: interesting. so you still write java, but clojure is to get familiar with something?
22:49	bounb	anyone by the name jony hudson itc?
22:50	iamdustan	justin_smith: with ring and compojure and the like?
22:50	avi__	iamdustan: I try to avoid Java, but yes
22:51	andrewchambers	iamdustan: I have played with writing parts of a compiler in clojure with core.logic
22:51	avi__	iamdustan: it allowed me to plumb the guts of DB4o and see the crazy stuff it was doing
22:51	andrewchambers	didnt actually use it for a few reasons
22:52	andrewchambers	then I wanted to use clojurescript + core.async + om for a ui for a payment system
22:52	andrewchambers	but shelved that project for now
22:52	andrewchambers	I like to try and think of projects that clojure will be good for as a hobby :P
22:52	justin_smith	iamdustan: ring and our own custom router, edn record mapping layer, and template renderer (the project is open sourced, called caribou)
22:53	iamdustan	if/when I get to the point of clojurescript + om I will let you know to pick that project back up
22:53	justin_smith	caribou is a bit too heavy weight / frameworky for clojure (it's an adaptation of some ruby stuff built for an agency to smooth a transition)
22:53	andrewchambers	clojure also changed the way i write some code at work in normal java
22:53	andrewchambers	more immutability
22:53	andrewchambers	more atomic swapping of values
22:55	bounb	avi__: that's interesting.
22:55	bounb	thanks
22:56	andrewchambers	more emphasis on pure functions too
22:58	avi__	so much in java needs to be immutable
22:58	avi__	thank goodness they made the strings immutable