#clojure – 2014-09-13

2014-09-13

00:00	justin_smith	and of course, that really means the general programming style that works with immutibility
00:00	catern	learning that value has made programming in mutable languages more painful!
00:00	justin_smith	why? why not just program immutibly in whatever language?
00:00	justin_smith	in clojure, you can still need to touch mutible state or APIs in the jvm
00:01	justin_smith	though its true you will find less immutible infrasctucture, some stuff isn't so hard to adapt
00:03	ToxicFrog	So I have the following form: (some-> (:name x) (.equalsIgnoreCase (:name y)))
00:03	ToxicFrog	I want to eliminate reflection, and know that (:name x) and (:name y) have type String.
00:04	ToxicFrog	Where do I put the ^String annotations?
00:04	ambroseb_	(let [^String a (:name x)] (some-> a ....))
00:04	ToxicFrog	(rather, I know that (:name y) has type String and (:name x) is either a String or nil, but if it's nil the some-> will never get around to making the method call anyways)
00:04	justin_smith	ToxicFrog: this code may be clearer without the some-> form if annotated
00:06	ToxicFrog	ambroseb_: aah. The docs say that type hints can be placed on "expressions" as well as parameters, var-names and let-names, but isn't really clear on how you do that.
00:06	ToxicFrog	So I was hoping I could attach the ^String to (:name x) directly somehow.
00:06	ambroseb_	ToxicFrog: mm it's an art
00:06	ambroseb_	:)
00:06	ambroseb_	ToxicFrog: especially when you're passing nil ...
00:07	ToxicFrog	Actually, looking at it, I'm not sure I am passing nil. The some-> may be a holdover from an earlier version.
00:31	michaniskin	is it possible to have nested nrepl clients?
00:31	michaniskin	like if i have a repl session going can i attach to another nrepl server
00:32	justin_smith	michaniskin: yeah, I would be surprised if it did not work, via clojure.tools.nrepl
00:32	michaniskin	i must be doing something wrong, it disconnects me from the current session
00:33	justin_smith	hrm - I would think it would be re-entrant
00:33	ToxicFrog	Dear god the type signature on every?
00:33	justin_smith	haha, I can only imagine
00:33	ToxicFrog	I was expecting something like [(Seqable Any) -> Boolean]
00:33	ToxicFrog	Instead it's (All [x y] (IFn [(IFn [x -> Any :filters {:then (is y 0), :else tt}]) (Coll x) -> java.lang.Boolean :filters {:then (is (Coll y) 1), :else tt}] [(IFn [x -> Any :filters {:then (is y 0), :else tt}]) (U (IPersistentCollection x) nil) -> java.lang.Boolean :filters {:then (is (U (IPersistentCollection y) nil) 1), :else tt}] [(IFn [x -> Any]) (U (Seqable x) nil) -> java.lang.Boolean]))
00:34	justin_smith	woah
00:34	ToxicFrog	(why am I looking at this? Because core.typed doesn't come with type annotations for clojure.core/not-any?)
00:35	ToxicFrog	(so I figured I'd check every?, which I thought would have the same type)
00:35	ToxicFrog	(I'm not so sure anymore)
01:15	ToxicFrog	justin_smith: so it turns out to be a lot more readable if you run it through pprint and ignore the filters.
01:16	ToxicFrog	I am a bit confused as to why it has three signatures, though -- one taking (Coll x), one (U (Seqable x) nil), and one (U (IPersistentCollection x) nil)
01:27	ToxicFrog	Argh. It's complaining that String/contains can't be applied to arguments (U String nil), but String implements CharSequence and the code in fact runs fine
01:27	ToxicFrog	maybe this will make more sense in the morning
02:39	dorkmafia	http://paste.debian.net/120653/ how come that doesn't work? I also tried {:libpaths [["python/"]["skype4py/Skype4Py/"]] } but {:libpaths ["python/"]} working?
02:40	dorkmafia	/ing/d
06:45	dagda1	is there anything similar to respond_to? in clojure that will let me know if a datatype has a method or am I thinking about this all wrong
06:45	justin_smith	dagda1: you can use clojure.reflect/reflect to get all slots and methods on an object
06:46	dagda1	justin_smith: thanks
06:46	justin_smith	or you can use instance? / isa? to see if it implements the protocol or interface defining that method
06:46	justin_smith	that's less expensive, but also less reliable
07:00	papachan	hi
07:01	papachan	i would like conj a map {} with doseq because i need to iterate each key value of another map
07:01	papachan	i was thinking something like this, but obviously it doesn't work
07:01	papachan	https://code.stypi.com/papachan/conj.clj
07:32	milos_cohagen	papachan: if you want to create a new map, from an old map, with some transformations in between, you can use reduce perhaps
07:32	milos_cohagen	,(reduce (fn [m [k v]] (assoc m k v)) {} {:a 0 :b 1})
07:32	papachan	milos_cohagen thank you i will try with reduce
07:32	clojurebot	{:a 0, :b 1}
07:33	milos_cohagen	doXXX functions are mostly for performing side effects, like mutating something, printing something, etc
07:34	milos_cohagen	clojure functions like conj or assoc or "pure", no side-effects
07:35	milos_cohagen	i mean "are pure" not "or pure"
07:37	papachan	milos_cohagen ok it does the same think when i am using conj
07:41	milos_cohagen	papachan would be happy to take a look if you post a snippet
07:43	papachan	milos_cohagen,
07:44	papachan	https://code.stypi.com/papachan/snippet.clj
07:49	milos_cohagen	papachan thanks but from that repl session i'm having a hard time interpreting your goal. what are the requirements of params-parser
07:51	papachan	milos_cohagen i am receiving a params {:model "android" :version "1.2.1"}
07:52	milos_cohagen	ok
07:52	papachan	need to put it in a session cookie structure
07:52	papachan	as at final
07:52	papachan	and assoc with the actual session cookie
07:54	papachan	i was working with do seq but its not the result: it executed each times it detect a keyword
07:55	milos_cohagen	ok so, we want a function f which accepts two maps as arguments a and b. (defn f [a b] ..)
07:55	milos_cohagen	map "a" keys and vals should be added in someway to map "b"?
07:57	milos_cohagen	and an updated version of map "b" should be returned?
07:57	papachan	yes i was trying with your reduce code, but still don't understand how i recur each keywords to make a new map structure
07:57	papachan	should return the final at my snippet but not repeated
08:01	milos_cohagen	ok so we do (defn f [a b] ...), the ... could be a reduce form, so we say (defn f [a b] (reduce reduce-fn b a))
08:01	papachan	ok
08:03	milos_cohagen	reduce-fn accepts two args, the accumulated vale, which starts with "b", and second arg is the first k,v of "a", and should return the new accumulated value
08:04	milos_cohagen	sorry hard to explain, i can't just write the answer for you because your examples don't show what "a" and "b" values look like exactly with exact desired output
08:06	papachan	milos_cohagen i am trying to make something work. will try your example
08:17	milos_cohagen	good luck!
08:30	kqr	can I somehow figure out the type of an object I have in my clojure program? it exhibits some interesting properties and I'd like to know what it is
08:30	kungi	I am trying to test my core async code but the test finishes with the report before the assertations in the go-blocks had a chance to run
08:31	kungi	Is there an asynchronous testing helper for clojure.test?
08:31	kungi	kqr: class maybe what you want
08:31	kungi	,(class "")
08:31	clojurebot	java.lang.String
08:31	kqr	kungi, yes I did, thanks
08:32	kqr	it's just a java.io.File
08:32	kqr	interesting!
08:54	kqr	does anyone know why I get the exception: http://lpaste.net/2155899009351286784 ? even though according to javadocs one of the copy methods take two paths as arguments?
08:55	kqr	...wait
08:55	kqr	clojure has a copy function?
08:55	kqr	just maybe i should use that instead
09:00	kqr	but that fails too
09:00	kqr	hm
09:01	kungi	kqr: https://clojure.github.io/clojure/clojure.java.io-api.html
09:01	kqr	who woulda thunk copying files would be so difficult on the jvm :D
09:01	kungi	kqr: there is also a copy function
09:01	kqr	i saw that
09:01	kqr	but if I try to (clojure.java.io/copy (File. "t1.txt") (File. "t2.txt")) it complains about one of them not being a var
09:02	kqr	if I assign them to variables before doing the call I get an IllegalArgumentException in multimethod "do-copy"
09:02	ToxicFrog	kqr: re Files/copy: is it possible that the reflector is finding the wrong method for it?
09:03	ToxicFrog	There's a bunch of different versions of copy, including one that takes (Path OutputStream) and one that takes (Path Path); if it's only finding the former, there's your problem
09:03	kqr	http://lpaste.net/4103219378718244864
09:03	kqr	full version of the error I get with the clojure-native copy function
09:04	kqr	ToxicFrog, yeah, that's what I suspected... but I don't know how I can make it find the other one
09:05	ToxicFrog	kqr: hmm. I tried adding type annotations to mark both src and dest as ^Path but that didn't work :/
09:06	kqr	weird
09:07	ToxicFrog	Oh, I see, reading the docs on java interop it looks like type hints help it on resolving the type of this when making method calls but no mention is given of resolving arguments in overloaded functions
09:07	kqr	well
09:07	kqr	(clojure.java.io/copy (clojure.java.io/file "t.txt") (clojure.java.io/file "t2.txt")) works
09:08	kqr	even though clojure.java.io/file according to docs passes the argument straight to java.io/File
09:10	ToxicFrog	kqr: ok, but that's expected?
09:10	ToxicFrog	Look at the docs: "Input may be an InputStream, Reader, File, byte[], or String."
09:10	ToxicFrog	clojure.java.io/copy supports Files but not Paths
09:11	kqr	ToxicFrog, shit yeah you're right
09:11	kqr	ToxicFrog, I thought my variables source and dest were files, but they are paths
09:11	kqr	ToxicFrog, thanks
09:12	kqr	they were files for the longest time, then I made them into paths before asking here :)
09:15	ToxicFrog	Huh. I must not understand how to set type hints.
09:15	ToxicFrog	I thought they were stored in the metadata, but:
09:15	ToxicFrog	user=> (let [^Path p (.toPath (File. "/etc/passwd"))] (meta p))
09:15	ToxicFrog	nil
09:16	kqr	i thought so too
09:28	ToxicFrog	Huh.
09:28	ToxicFrog	Ok, so if I use with-meta, everything works fine
09:28	ToxicFrog	If I use the ^ macro, no metadata is applied
09:28	ToxicFrog	Oh. Because I'm using it in the wrong position.
09:28	ToxicFrog	asdfh
09:35	kqr	haha
09:36	ToxicFrog	But it still doesn't work with Path!
09:36	ToxicFrog	aaaaaaaaagh
09:36	ToxicFrog	user=> (def x ^int {}) (meta x)
09:36	ToxicFrog	{:tag #<core$int clojure.core$int@12a133b2>}
09:36	ToxicFrog	user=> (def src ^Path (.toPath (File. "/tmp/foo"))) (def dst ^Path (.toPath (File. "/tmp/bar"))) (meta dst)
09:36	ToxicFrog	nil
09:57	kqr	is there a way to store some information about my application in a separate file? i'm trying to create a web app, and both ragtime and korma wants information about the database but in separate formats
09:58	kqr	and i'd rather not commit the details of the database to the repo
09:58	rweir_	I've used https://github.com/weavejester/environ pretty happily
09:58	rweir_	which doesn't help with getting the stuff into your libraries, but it does do the 'what are the values' bit
10:00	kqr	I just now realised that project.clj is a normal clojure file
10:00	kqr	that certainly helps
10:01	rweir_	yeah
10:01	rweir_	think carefully about how much magic you put in there though
10:03	kqr	well ragtime wants a jdbc url, so somehow I need to convert the db details into a url
10:03	kqr	is that too much magic?
10:03	rweir_	ah
10:03	rweir_	I'd probably do that in my real-code instead of project.clj, but I don't have a strong opinion either way :)
10:03	kqr	how'd that work?
10:04	kqr	what I'm imagining is a file that simply contains a map with host, db name, username and password
10:04	rweir_	ie do at the point where you first interact with ragtime [I've not used it, so apologies if that's a stupid answer]
10:04	kqr	and then project.clj and src/db/schema.clj must use that information
10:04	kqr	the first interaction with ragtime is in the project.clj file
10:04	rweir_	oh, interesting
10:04	kqr	or rather, that's where you're supposed to tell it which database to use
10:05	rweir_	ah, I see [looking at the docs]
10:05	kqr	the broader context is that I'm trying to learn the luminus framework
10:05	kqr	I find it as confusing as the next guy
10:20	dagda1	is there a way to find the common elements in 2 vectors?
10:21	zot	convert to set and do intersection?
10:47	gfredericks	anybody know what's up with marmalade?
10:51	Raynes	gfredericks: Everything sucks.
10:52	gfredericks	(inc Raynes)
10:52	gfredericks	a few of my packages aren't available after removing marmalade from my list
10:57	gfredericks	lazybot being gone is symbolic of everything being broken this morning
10:58	Bronsa	it's not like lazybot being gone is a first
10:59	Raynes	you know what
11:00	Raynes	Fuck it
11:00	justin_smith	Bronsa: that's the difference between FUBAR and SNAFU
11:00	Raynes	IT'S THE ONLY WAY TO BE SURE
11:00	hyPiRion	Raynes: Have a supervisor on it?
11:00	hyPiRion	get mail every time it crashes
11:01	Bronsa	Raynes: <3
11:01	Raynes	hyPiRion: I'd love for it to be as simple as monitoring it, but it's not quite that easy.
11:01	Raynes	hyPiRion: When lazybot dies his process almost never dies.
11:01	hyPiRion	Raynes: oh, right
11:01	Raynes	He is designed in such a way that if he can't talk to one IRC he doesn't really care that much
11:01	Raynes	The problem is he can't tell when he can't talk to ANY irc :P
11:02	justin_smith	Raynes: I assume it also has to detect and act on disconnects fro mthe server
11:02	Raynes	It does not.
11:02	hyPiRion	It's the "100% CPU time after server disconnect"-bug?
11:02	Raynes	Uses an ancient unmaintained version of irclj that doesn't handle disconnects at all, really.
11:02	Raynes	Nah, he just loses connection and can't do anything about it
11:02	Raynes	So he sends pings every now and then
11:02	hyPiRion	ah, haha
11:02	Raynes	Hoping for an answer
11:02	Raynes	It's quite sad really
11:02	Raynes	Let me put the kid out of his misery
11:03	justin_smith	you could make him close the connection and reconnect every half hour
11:03	justin_smith	lol
11:03	Raynes	That's srs engineering right there
11:03	hyPiRion	Well, if anyone has nothing to do in their sparetime, they could patch up poor lazybot
11:03	Raynes	hyPiRion: Step one: use newer half-assed irclj implementation.
11:03	Raynes	Step two: figure out it needs to be less half assed, make it less half assed
11:03	Raynes	Step three: #win
11:04	hyPiRion	Raynes: I was talking about step two mostly
11:04	hyPiRion	implement proper irclj
11:04	Raynes	The newer irclj is pretty solid
11:04	Raynes	I don't think it actually lacks much of anything lazybot would need.
11:08	gfredericks	Raynes: so a vigorous manual restart tends to fix transient problems?
11:08	Raynes	gfredericks: It doesn't actually go down that much.
11:08	gfredericks	but when it does that fixes it?
11:08	Raynes	Well yes, because the only 'problem' is usually just that it has lost connection for one reason or another.
11:09	Raynes	Birds sitting on power lines and shit.
11:09	Raynes	Normal stuff.
11:09	Raynes	Irclj needs handling for connection loss and lazybot needs new irclj after that.
11:09	Raynes	Then he will be legion without my help.
11:09	gfredericks	the hipchat bot I run at work is run in a bash loop that kills/restarts every ten minutes
11:10	Raynes	Sounds like an average Python program.
11:10	justin_smith	gfredericks: that was my "joke" suggestion
11:10	gfredericks	it has the advantage that it's easy to do :P
11:10	Raynes	Hey
11:11	Raynes	Could be like "Hmmmmmm... Nobody has said anything on any of these 40 channels I'm in in the past half hour..."
11:11	Raynes	"I... guess I should kill myself now?"
11:11	Raynes	"(System/exit 0) ; goodbye cruel world"
11:12	justin_smith	Raynes: sounds like my ex having a bpd attack
11:13	justin_smith	Raynes: isn't there an IRC protocol level thing for checking if you are connected?
11:13	Raynes	justin_smith: What's the first thing they do to a robot at the doctor's office?
11:13	Raynes	THEY CHECK HIS BYTLES.
11:14	Raynes	justin_smith: Well, ideally your socket realizes nothing's popping out the other end, but you can send PINGs to the server and if you do not get a response in a timely manner you can assume you're lost in interspace.
11:14	justin_smith	Raynes: like every half hour he could run /msg nickserv listchans
11:14	justin_smith	or just that
11:14	Raynes	IRC is super async.
11:15	justin_smith	right, distributed, async
11:15	Raynes	It's real hard to be like "gimme a list of channels" and then say "oh, here's my list of channels"
11:15	Raynes	You kinda have to send 'gimme a list of channels' off into the void and then receive the response from the void.
11:15	gfredericks	so srsly should I expect marmalade to be down for a long time?
11:15	Raynes	The problem is six other commands could return before that one, despite your ordering :P
11:15	Raynes	gfredericks: It's marmalade. Expect it to never come back up.
11:15	justin_smith	Raynes: reminds me of my experiments with mud scripting
11:16	justin_smith	basically you need multiple state machines ready to be triggered or finalized, because who knows which part of your logic a given message may be destined for
11:16	gfredericks	I need to give up on emacs package managers and just maintain a personal collection of .el files, don't I?
11:17	justin_smith	gfredericks: technomancy seems fond of el-get
11:17	gfredericks	what's that? another package manager?
11:17	justin_smith	http://www.emacswiki.org/emacs/el-get
11:17	gfredericks	my current problem is that some of my packages are only in this one repo that Raynes said will never come back
11:17	xeqi	gfredericks: I'm going to guess its maintained by one person, so yes
11:18	justin_smith	gfredericks: above link has a "why have both" rationale (up to you whether it's reasonable or not, of course)
11:18	gfredericks	"Think apt-get for emacs"
11:18	Raynes	gfredericks: It is way too early and I'm way too bitter to say one single useful non-silly thing right now.
11:19	gfredericks	Raynes: it's like 10am amirite
11:19	Raynes	I woke up at 7AM
11:19	Raynes	Didn't even get to go to the toilet before having to solve crisises.
11:19	gfredericks	waking up at 7am is sleeping in for me
11:19	Raynes	Waking up at noon is sleeping in for me.
11:20	gfredericks	I woke up at 8am today and that was highly unusual
11:23	gfredericks	who is going to stramg lop
11:24	justin_smith	bizzaro justin am going stramg lop thisy ear
11:24	justin_smith	(not actually going to strange loop)
11:26	gfredericks	does cider have a buffer-local current-ns variable?
11:27	gfredericks	I was looking at my 0.5.0 source and it seemed to mostly just infer based on an initial (ns ...) form, which doesn't help my org-babel uses
11:28	gfredericks	I see nrepl-client.el has (defvar-local nrepl-buffer-ns ...)
11:32	justin_smith	gfredericks: edebug is an awesome stepping debugger, that shows you the result of every form as it is evaluated, by the way
11:34	gfredericks	justin_smith: thanks; I'm still n00b enough that extra tools are likely to just layer confusion
11:37	allen	does anyone know of a plugin that allows me to load clojar or external libraries from within a lein repl
11:37	allen	similar to https://github.com/rkneufeld/lein-try
11:38	allen	except have the ability to load different libraries as we go with the flow
11:38	Raynes	https://github.com/cemerick/pomegranate
11:38	xeqi	alembic
11:39	allen	Raynes, beautiful. Thanks
11:39	allen	(inc Raynes)
11:39	lazybot	⇒ 51
11:39	gfredericks	hi lazybot
11:39	Raynes	Whatever is at the top of the inevitable 1200 libraries on top of pomegranate I guess
11:40	gfredericks	gimme uses fireflox uses alembic uses pomegranate so if you're not using gimme you're basically losing
11:41	Raynes	It looks like alembic doesn't use pomegranate?
11:41	Raynes	Which is horrifying
11:41	xeqi	it does
11:41	gfredericks	I use pomegranate, with a helper: https://github.com/gfredericks/repl-utils/blob/master/src/com/gfredericks/repl.clj#L12-18
11:41	Raynes	xeqi: Oh, a transitive dep?
11:41	Raynes	Lovely
11:41	xeqi	I think through lein-as-resource
11:42	hugoduncan	which is woefully out of date
11:43	mantas	$ lein run [11:39:52]
11:43	mantas	Exception in thread "main" java.lang.ClassCastException: clojure.lang.Symbol cannot be cast to clojure.lang.Keyword, compiling:(caffeinate/web.clj:1:1)
11:43	mantas	line one is simple: (ns caffeinate.web
11:43	mantas	any explanation as to why this happens?
11:43	Raynes	Well, I'd close that for starters.
11:43	justin_smith	allen: pallet/alembic is easier to use than pomegranate
11:44	Raynes	Line one is a red herring, mantas. Please show us your whole ns form
11:44	allen	ok cool, i'll check out all three
11:44	xeqi	mantas: through the magic of macros, line 1 is basically everything in the (ns ..) form
11:44	allen	ohh nvm alembic is developed by pallet
11:44	Raynes	Is pomegranate difficult to use? O.o
11:45	xeqi	Raynes: well, you do have to pass the repositories. and if you have mirrors...
11:45	justin_smith	Raynes: alembic uses the project.clj dep syntax, and is automatically recursive
11:45	hugod	alembic keeps pomegranate off your project's classpath
11:45	justin_smith	and you don't need to specify repos at all
11:45	xeqi	hugod: does alembic keep track of what is already been distilled?
11:45	xeqi	to avoid different distilled calls bring in conflicting deps?
11:46	hugod	xeqi: it checks what is already loaded in the clsspath
11:46	hugod	and warns on conflicts
11:46	Raynes	Well, clearly alembic is the best thing since sliced ham.
11:46	justin_smith	xeqi: alembic, in my experience, does not import things if some other version is already imported
11:46	xeqi	right, I thought it had something that way
11:46	justin_smith	Raynes: I found it much easier to use compared to pomegranate
11:46	Raynes	I understand
11:48	zeebrah	i'd like to trace a function for debugging. is it doable?
11:48	justin_smith	zeebrah: tools.trace
11:48	justin_smith	https://github.com/clojure/tools.trace very easy to use
11:49	zeebrah	justin_smith: cheers
11:50	zeebrah	this isn't quite what i had in mind. i was hoping for a CL like trace :(
11:51	justin_smith	zeebrah: tracing the execution of the function?
11:51	zeebrah	yep
11:52	justin_smith	zeebrah: I hear tell cursive clojure (it's an intellij idea plugin) has good step debugging, but have not actually tried it myself
11:53	zeebrah	justin_smith: actually wait, trace-ns is kinda cool and does the job :)
11:54	justin_smith	zeebrah: it doesn't get you the step by step internals though, but I guess it gets you your helper functions
11:55	justin_smith	on a more insane end of things, you can use jdb to trap and step and interact with the stack on the byte code level
11:55	justin_smith	but if trace-ns suffices, cheers :)
11:55	zeebrah	justin_smith: thanks for the help :)
11:56	justin_smith	np
11:57	kungi	I would like to have an atom containing a map of key -> #set pairs. How do I append to such a structure? When the #set belonging to a key is empty it is easy, but how do I append to an existing set in a map with a swap! operation?
11:58	justin_smith	,(swap! (atom {:numbers #{0}}) update-in [:numbers] conj 1 2 3)
11:58	clojurebot	{:numbers #{0 1 3 2}}
11:58	justin_smith	definitely looks weird, as both swap and update-in take their args just stacked on the end without parens
11:59	kungi	justin_smith: yes it does :-)
11:59	kungi	justin_smith: Can I add a non existing key that way?
11:59	gfredericks	it's fun once you get the hang of it though
11:59	gfredericks	yes
11:59	kungi	,(swap! (atom {:numbers #{0}}) update-in [:blubber] conj 1 2 3)
11:59	clojurebot	{:blubber (3 2 1), :numbers #{0}}
11:59	kungi	Awsome!
11:59	justin_smith	kungi: you need fnil for that if it needs to be a set
11:59	gfredericks	(fnil conj #{}) instead of conj
12:00	justin_smith	,(swap! (atom {:numbers #{0}}) update-in [:blubber] (fnil conj #{}) 1 2 3)
12:00	clojurebot	{:blubber #{1 3 2}, :numbers #{0}}
12:00	mantas	huh, thanks! yes, the issue was later in the (ns... ) declaration. i didn't know macros had this effect.
12:01	kungi	justin_smith: Thank you
12:01	justin_smith	np
12:02	gfredericks	,(def my-atom (atom {:foo [1 2 3]}))
12:02	clojurebot	#'sandbox/my-atom
12:02	gfredericks	,(swap! my-atom update-in [:foo 0] dec)
12:02	clojurebot	{:foo [0 2 3]}
12:03	gfredericks	,(swap! my-atom update-in [:foo 0] + 42)
12:03	clojurebot	{:foo [42 2 3]}
12:19	allen	date
12:21	iartarisi	Hello, I'm using Korma and trying to restrict the number of fields from a select query. I'd like to get SELECT games.white_id FROM games; but I get all the fields plus white_id instead:
12:21	iartarisi	(dry-run (select games (fields :white_id)))
12:21	iartarisi	dry run :: SELECT "games"."stones", "games"."white_id", "games"."black_id", "games"."white_id" FROM "games" :: []
12:21	iartarisi
12:22	iartarisi	I have the latest korma: 0.4.0
13:10	Shoop	Whats the best way to turn ((1 1) (2 2)) into [[1 1] [2 2]]?
13:11	shosti	,(vec (map vec '((1 1) (2 2))))
13:11	clojurebot	[[1 1] [2 2]]
13:12	justin_smith	,(mapv vec '((1 1) (2 2)))
13:12	clojurebot	[[1 1] [2 2]]
13:16	Shoop	Thanks :D
13:18	Shoop	Is vec the same as #(apply vector %)?
13:19	justin_smith	$source vec
13:19	lazybot	vec is http://is.gd/GCHYnT
13:20	Shoop	not literally but conceptually
13:20	justin_smith	interestingly, if you supply an array as the argument, it aliases it, and you break the contract of vectors if you later modify the array
13:23	justin_smith	where vector will not do anything like that
13:27	Jaood	cider needs some keep-alive method
13:42	gfredericks	,(def argh (into-array [0 1 2 3 4]))
13:42	clojurebot	#'sandbox/argh
13:42	gfredericks	,(seq argh)
13:42	clojurebot	(0 1 2 3 4)
13:42	gfredericks	,(def vee (vec argh))
13:42	clojurebot	#'sandbox/vee
13:42	gfredericks	,vee
13:42	clojurebot	[0 1 2 3 4]
13:42	gfredericks	,(aset argh 2 :hehe)
13:42	clojurebot	#<ArrayStoreException java.lang.ArrayStoreException: clojure.lang.Keyword>
13:42	gfredericks	,(aset argh 2 42)
13:42	clojurebot	42
13:42	gfredericks	,vee
13:42	clojurebot	[0 1 42 3 4]
13:43	gfredericks	,(doc vec)
13:43	clojurebot	"([coll]); Creates a new vector containing the contents of coll. Java arrays will be aliased and should not be modified."
13:43	gfredericks	welp can't say it didn't warn you
13:43	gfredericks	does it do that even for large arrays?
13:44	gfredericks	,(def argh (into-array (range 100000)))
13:44	clojurebot	#'sandbox/argh
13:44	gfredericks	,(def vee (vec argh))
13:44	clojurebot	#'sandbox/vee
13:44	gfredericks	,(aset argh 0 42)
13:44	clojurebot	42
13:44	gfredericks	,(take 10 vee)
13:44	clojurebot	(0 1 2 3 4 ...)
13:45	justin_smith	fascinating
13:45	gfredericks	it'd have to break it up at some point anyways; might as well be immediately
13:45	justin_smith	so maybe "will be" should say "can be"
13:45	gfredericks	right :)
13:46	gfredericks	we need a variant of the word "modify" for talking about immutable data structures
13:47	gfredericks	how about "schmodify"
13:47	gfredericks	or "schmutate"
13:47	justin_smith	elaborates?
13:47	gfredericks	yeah?
13:47	justin_smith	exponunds upon
13:47	justin_smith	err, expounds upon
13:47	gfredericks	not really a good analogy from normal life
13:51	jjl`	hi all. I'm writing some clojure that will need to be usable from java. what's the simplest way of writing test cases in java within a clojure project?
13:51	gfredericks	jjl`: test cases for automated testing?
13:51	jjl`	yes
13:51	gfredericks	leiningen has an option for specifying the location of java sources
13:52	gfredericks	I guess the rest of the answer depends on how you want to execute/launch the tests
13:52	gfredericks	e.g., do you mind writing tests in clojure that call your java code?
13:52	gfredericks	or do you need a java test framework?
13:53	jjl`	i think okay with the former, provided the java test harness doesn't get shipped in the final jar
13:53	gfredericks	yeah, leiningen lets you distinguish between dev stuff and final-package stuff
13:54	jjl`	okay. do you know which project.clj keys i'll need to read up on?
13:56	gfredericks	check the sample.project.clj file in the leiningen repo; they'll be one called :java-source-path or something similar
13:57	gfredericks	then try writing a test with clojure.test that runs your java code
13:57	jjl`	yeah, i just found that. presumably :exclusions is the other one i need?
13:57	gfredericks	or first you could try `lein run -m MyClass`
13:57	gfredericks	which I think works
13:57	gfredericks	jjl`: if you put it in the :dev profile then you don't need to exclude anything
13:57	gfredericks	:profiles {:dev {:java-source-paths ...}}
13:57	jjl`	oh, handy :)
13:58	jjl`	thanks :)
13:58	gfredericks	np
14:28	nkozo	I start a "lein repl" and then connect from emacs using cider, now if a Thread prints to out (using the timbre logging library) only the "lein repl" prompt shows the output, the cider nrepl session doesn't show it. Why? How you can print to both?
14:44	gfredericks	nkozo: um.
14:44	gfredericks	when you say "a Thread" I assume you mean not the thread you're using directly from cider
14:49	gfredericks	I think I know what all the pieces involved are, I just don't know what the best approach is
15:17	ultranapoletano	ciao
15:17	ultranapoletano	!list
15:27	jjl`	is there a way of building an abstract class member in clojure? i need it for some java interop and i'd be loathe to write it in java
15:30	gfredericks	what's an abstract class member?
15:31	jjl`	an abstract method
15:31	gfredericks	what would that look like in java?
15:32	jjl`	abstract class Foo { abstract void bar(); }
15:32	gfredericks	I'm curious what sort of java interop that's useful for
15:34	jjl`	Basically I'm building something where arbitrary objects will be passed around because of dynamic typing. All lovely and fine in clojure, but in javaland, you need type safety. I'd like a generic callback mechanism a la Callable, but different
15:35	gfredericks	why not an interface?
15:36	jjl`	because an interface doesn't permit you to enforce a given constructor
15:37	gfredericks	welp I don't know of any way to do abstract stuff in clojure; it doesn't sound like it'd be intolerable to write it in java
15:38	jjl`	no, indeed, it's not that much hassle, it's just i'd prefer to keep as much in clojure as possible
15:45	arohner	is #datomic logged anywhere?
15:46	TEttinger	arohner, it would be kinda ironic if the channel for a database wasn't logged in some database
15:46	arohner	google doesn't seem to know about it
15:47	redblackbit	any idea why (meta ^:foo 'bar) return nil while the documentation states that: Symbols and collections support metadata
15:48	TEttinger	,(meta ^:foo +)
15:48	clojurebot	nil
15:48	TEttinger	,(meta +)
15:48	clojurebot	nil
15:48	TEttinger	hm
15:49	TEttinger	,(meta inc)
15:49	clojurebot	nil
15:49	TEttinger	might need var-quote
15:49	redblackbit	right
15:49	arohner	+ resolves to the fn
15:49	arohner	,(meta #'+)
15:49	clojurebot	{:added "1.2", :ns #<Namespace clojure.core>, :name +, :file "clojure/core.clj", :inline-arities #<core$_GT_1_QMARK_ clojure.core$_GT_1_QMARK_@6e4c32>, ...}
15:49	redblackbit	but why doesn’t it work with a symbol?
15:49	TEttinger	,(meta ^:foo #'bar)
15:49	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve var: bar in this context, compiling:(NO_SOURCE_PATH:0:0)>
15:50	arohner	,(meta (with-meta 'bar {:foo true}))
15:50	clojurebot	{:foo true}
15:50	gfredericks	redblackbit: it's because of what ' does
15:50	TEttinger	maybe ^:foo isn't evaluated until the form is done?
15:50	gfredericks	,(meta ^:foo (quote bar))
15:50	clojurebot	nil
15:50	gfredericks	,(meta (quote ^:foo bar))
15:50	clojurebot	{:foo true}
15:50	gfredericks	redblackbit: your code is equivalent to the first of those two ^
15:51	redblackbit	gfredericks: oic
15:51	gfredericks	also there is:
15:51	redblackbit	gfredericks: makes kinda a pain to attach metadata to symbols though
15:51	gfredericks	,(with-meta 'bar {:foo true})
15:51	clojurebot	bar
15:51	gfredericks	,(meta (with-meta 'bar {:foo true}))
15:51	clojurebot	{:foo true}
15:54	redblackbit	gfredericks: anyway, thx!
15:54	gfredericks	np
16:11	danielszmulewicz	Question to the emacs power users: I'm writing a minor mode that makes sense only with clojurescript files, however, there is no clojurescript-mode hook. Any ideas?
16:16	gfredericks	is there a clojurescript-mode?
16:23	danielszmulewicz	gfredericks: People have written their own, but now with cider and the official stack. Anyway, I posted an issue on cider's github.
16:41	noncom	,(.getConstructor (java.lang.Class/forName "java.util.ArrayList"))
16:41	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: No matching field found: getConstructor for class java.lang.Class>
16:42	noncom	^^^ why is it searching for the constructor in class Class ? why does not it looking for the constructor in class ArrayList ?
16:46	dbasch	noncom: you’re calling a method that doesn’t exist
16:47	dbasch	: ,(.getConstructors (java.lang.Class/forName "java.util.ArrayList"))
16:47	dbasch	&(.getConstructor (java.lang.Class/forName "java.util.ArrayList"))
16:47	lazybot	java.lang.IllegalArgumentException: No matching field found: getConstructor for class java.lang.Class
16:47	dbasch	&(.getConstructors (java.lang.Class/forName "java.util.ArrayList"))
16:47	lazybot	⇒ #<Constructor[] [Ljava.lang.reflect.Constructor;@b3cde94>
16:48	dbasch	&(first (.getConstructors (java.lang.Class/forName "java.util.ArrayList”)))
16:48	lazybot	java.lang.RuntimeException: EOF while reading string
16:49	dbasch	&(first (.getConstructors (java.lang.Class/forName "java.util.ArrayList")))
16:49	lazybot	⇒ #<Constructor public java.util.ArrayList(java.util.Collection)>
16:55	noncom	dbasch: thanks!
17:12	raspasov	hi everyone
18:21	onielfa	Hello, I have a stupid problem. When trying to use println like (println "Hello") in the REPL, I got a java.lang.NoSuchMethodError. Am I missing something?
18:22	hyPiRion	onielfa: `lein downgrade 2.4.2`
18:23	hyPiRion	we're working on it, there's a bug in latest stable =/
18:23	onielfa	hyPiRion: Thanks a lot! I am going to downgrade :)
18:25	onielfa	hyPiRion: It works now :) Let's continue learning Clojure, thanks!
18:25	hyPiRion	onielfa: no problem =)
20:48	Bronsa	it's kind of unfortunate that disj only works on sets and not on maps
20:59	gfredericks	Bronsa: so (disj {1 2} [1 3]) would return {1 2}?
21:01	Bronsa	gfredericks: yeah, disj and dissoc have the same function signature
21:02	gfredericks	Bronsa: huwhat? dissoc doesn't take a value
21:02	Bronsa	gfredericks: wat
21:04	Bronsa	what I'd like is for disj to be (defn poly-disj [m & args] (apply (if (map? m) dissoc disj) args))
21:06	gfredericks	Bronsa: so then you lose the conj/disj symmetry
21:06	Bronsa	no? the opposite
21:06	gfredericks	the symmetry being the type
21:06	Bronsa	right now disj only works on sets
21:06	gfredericks	,(defn poly-disj [m & args] (apply (if
21:06	gfredericks	(map? m) dissoc disj) args))
21:06	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading>
21:06	raspasov_	yea conj works on everything
21:06	gfredericks	,(defn poly-disj [m & args] (apply (if (map? m) dissoc disj) args))
21:06	clojurebot	#'sandbox/poly-disj
21:07	gfredericks	,(-> {} (conj [1 2]) (disj [1 2]))
21:07	clojurebot	#<ClassCastException java.lang.ClassCastException: clojure.lang.PersistentArrayMap cannot be cast to clojure.lang.IPersistentSet>
21:07	gfredericks	,(-> {} (conj [1 2]) (poly-disj [1 2]))
21:07	clojurebot	[1 2]
21:08	gfredericks	,(-> #{} (conj [1 2]) (ploy-disj [1 2]))
21:08	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: ploy-disj in this context, compiling:(NO_SOURCE_PATH:0:0)>
21:08	gfredericks	,(-> #{} (conj [1 2]) (poly-disj [1 2]))
21:08	clojurebot	[1 2]
21:08	gfredericks	wat
21:08	gfredericks	,(defn poly-disj [m & args] (apply (if (map? m) dissoc disj) m args))
21:08	clojurebot	#'sandbox/poly-disj
21:08	gfredericks	,(-> {} (conj [1 2]) (poly-disj [1 2]))
21:08	clojurebot	{1 2}
21:08	gfredericks	,(-> #{} (conj [1 2]) (poly-disj [1 2]))
21:08	clojurebot	#{}
21:08	gfredericks	Bronsa: ^ that is the mismatch I'm referring to
21:09	gfredericks	(had to fix a boog in your poly-disj)
21:09	Bronsa	yeah sorry for the typo :(
21:10	Bronsa	gfredericks: I honestly don't see how what you're trying to say
21:10	Bronsa	sticking a key/value pair in a disj doesn't make any sense
21:10	gfredericks	wrt sets, conj and disj are opposites
21:10	gfredericks	conj takes a thing to add, disj takes a thing to remove
21:10	gfredericks	wrt maps, conj and poly-disj are not opposites in that sense
21:10	gfredericks	conj takes a PAIR to add, poly-disj takes a KEY to remove
21:12	Bronsa	gfredericks: different operations take different inputs
21:13	Bronsa	by your point dissoc is not the opposite of assoc
21:13	gfredericks	I might be imagining and intended pairing of conj and disj
21:13	gfredericks	an*
21:14	Bronsa	gfredericks: yeah, disj right now has definitely nothing to do with conj, the latter being highly polymorphic while the former being defined only on sets
21:14	gfredericks	the names seem related
21:14	gfredericks	and "defined only on sets" always made sense to me as being the only context where it could be defined
21:14	amalloy	Bronsa: i don't really agree: disj and conj seem to me like they're intended to be inverses
21:15	gfredericks	amalloy! thank goodness you're here!
21:15	amalloy	if disj worked on maps i'd expect it to work like gfredericks's version, not yours
21:15	amalloy	or, probably, to require an actual MapEntry
21:16	gfredericks	eh, conj takes a vector pair
21:16	amalloy	gfredericks: yeah, but the mapentry didn't exist yet. it's plausible that disj on the map would only remove entries which are in the map
21:17	gfredericks	does java-style never involve creating map entries before adding them to maps?
21:18	amalloy	i can't think of an instance of that, but maybe
21:18	gfredericks	amalloy: in any case do you have a less hand-wavey argument for this than I do, or is it just "they seem like inverses"?
21:18	Bronsa	amalloy: gfredericks it had never crossed my mind that (disj {} [k v]) might make sense, and I still don't think it does but point taken
21:19	Bronsa	I still wish there was a function that behaved like poly-disj, whichever its name
21:19	amalloy	no, i have nothing concrete
21:19	gfredericks	amalloy: at least there's two of us
21:20	amalloy	Bronsa: you can create that function, of course, with protocols. i'm sure you know that; are you hoping for it to be in core instead?
21:20	Bronsa	amalloy: yeah I meant in core
21:23	Bronsa	`remove-keys` maybe
21:24	amalloy	Bronsa: you could even call it `without`, like the java method on maps
21:24	amalloy	(-> my-set (without x y z))
21:25	amalloy	er, i guess i meant the method on sets
21:25	Bronsa	yeah without is probably better. remove-keys might suggest an association with select-keys, which only works on maps
22:56	wei	what’s a good way to pass data between two clojure processes? redis/carmine?
23:00	bbloom	wei: dramatically more information needed
23:04	wei	bbloom: good point. i have one process that controls multiple processes. the child processes are interchangeable and can start and stop unpredictably. requirements are that the messages be encrypted and durable across restarts. tangentially related, I recall Rich’s Language of the System talk had some great principles but he didn’t have time to cover how to implement such a system in Clojure
23:05	bbloom	are the processes on one box or distributed across several?
23:14	wei	bbloom: would it significantly change the design?
23:15	bbloom	wei: you can use the file system or you can use the network
23:15	bbloom	wei: why do you need encryption?
23:15	bbloom	wei: why do you need durability?
23:15	bbloom	you asked a reeeaaaallly general (and difficult) question
23:15	wei	thanks for humoring me :)
23:16	bbloom	maybe talk about your high level goal a bit
23:18	wei	haha, this reminds me of a previous conversation where you said, “guaranteed deliverability is a lie”
23:18	bbloom	wei: i would have reminded you of that :-P
23:20	wei	reading up on some design now.. i’ll come back later with more specific questions :)
23:21	vanila	hi
23:21	vanila	https://www.youtube.com/watch?v=f84n5oFoZBc
23:21	vanila	Hammock Driven Development - Rich Hickey