#clojure – 2015-08-08

2015-08-08

00:35	Kwhy_Not	Info
02:56	tmtwd	http://pastebin.com/8bzEsdWr
02:57	tmtwd	Can anyone explain this function to me?
03:00	justin_smith	tmtwd: that looks like a react component
03:01	tmtwd	justin_smith, is that what props is or is that an observation?
03:01	tmtwd	:)
03:02	tmtwd	but yeah, it is
03:02	tmtwd	hm, maybe there is something about reagent I'm just not getting
03:25	oddcully	tmtwd: the function returns a function, that takes the props. not knowning reagent, i'd say it gets called to render the component (later) and the props come from reagent (later)
03:26	tmtwd	oh, I see, the anonymous function is being returned, then it gets passed props, which then gets evaluated
03:27	tmtwd	what does {:keys [title on-save on-stop]} do?
03:29	oddcully	destructuring
03:29	arav93	How do I start off sampling clojure.zip. The entire namespace and functions in it seem really confusing!
03:30	oddcully	~destructuring
03:30	clojurebot	destructuring is http://clojure.org/special_forms#binding-forms
03:30	oddcully	i knew it!
03:35	tmtwd	oddcully, thanks, I could not find that for some reason
03:37	tmtwd	how come this returns nil? ( {:keys [yolo]} {:yolo 23})
03:38	tmtwd	it has to be in scope or something?
03:39	oddcully	because you call map on a map
03:39	oddcully	you lack the let
03:39	tmtwd	oh
03:39	oddcully	,(let [{:keys [x]} {:x 666}] x)
03:39	clojurebot	666
03:40	tmtwd	ohhh
03:40	tmtwd	odd
03:40	oddcully	s/odd/awesome!/
03:41	tmtwd	hehe, what is s?
03:43	clarkenciel	http://vim.wikia.com/wiki/Search_and_replace
05:17	crocket	Can clojure be used to create something like https://github.com/phpsysinfo/phpsysinfo ?
09:32	Bronsa	ambrosebs: ping
09:52	Bronsa	ambrosebs: I saw your ast-ref commits -- thanks! in case you find something else that's not updated, please run spec/buildref.sh so that the html doc gets rebuild too
11:30	Arcaed0x	Hi there...?
11:39	xcthulhu	Hey, is there a nifty way of getting a random free port?
11:40	xcthulhu	(I’m doing integration tests for a webserver)
11:40	xcthulhu	Hey cemerick, how do I get a random free port so I can do little integration tests with a real webserver?
11:40	xcthulhu	With, say, http-kit or whatever
11:42	cemerick	xcthulhu: pass 0 for port number, that will allocate a random available port
11:42	xcthulhu	Sweet how do I grab the port once it picks a random one?
11:43	xcthulhu	(I recognize there are docs)
11:45	xcthulhu	Here’s where you can grab it: https://github.com/http-kit/http-kit/blob/master/src/org/httpkit/server.clj#L32
11:45	xcthulhu	(for all of you future google people who stumble across this IRC chat)
12:14	weebz	does anyone know off the top of their head how to get cider in emacs to not have errors/exceptions display in a new buffer? it's a little annoying constantly closing and switching out of that buffer
12:15	weebz	i'm not sure where else it could be displayed, just looking to have something that isn't as interrupting if that makes sense?
12:17	wasamasa	it can pop it to a window
12:18	justin_smith	weebz: best fix is winner mode http://emacswiki.org/emacs/WinnerMode
12:18	justin_smith	weebz: with winner mode you can undo any random popped up anything easily
12:29	weebz	wasamasa, so it'll open in a new window that I can just C-x 0?
12:29	justin_smith	weebz: that would be c-x 5 0
12:29	justin_smith	it's easier to turn on winner-mode and hit C-c <left-arrow>
12:33	weebz	I'm a little confused how the undo is working. My issue right now is that I'm working with 2 windows (one source code, one REPL), and when I type an error in the REPL it opens up the error buffer in the source code window
12:34	weebz	winner undo just closes the window when I hit C-c <left>
12:34	justin_smith	then your history is not set up right...
12:34	justin_smith	try starting with one window, then splitting, then opening the right buffer in each half
12:34	weebz	very likely, I'm still quite new to Emacs
12:35	justin_smith	after you do all that, C-c left will take you back to the original window / buffer setup you wanted
12:35	justin_smith	also you can use C-c left / C-c right repeatedly to get all window / buffer configurations back as you like
12:37	weebz	it does what I want if I switch back to the REPL window and hit C-c <left>
12:38	weebz	but if I hit C-c <left> while the cursor is in the error window/buffer it reverts both windows to the source code buffer
12:38	justin_smith	weird...
12:38	justin_smith	what about just hitting q when the error buffer pops up?
12:38	wasamasa	weebz: no, q suffices
13:28	jonathanj	hrm, manifold.stream/put! returns synchronously?
13:29	jonathanj	is there a case where one might want to wait one put to complete before doing the next?
13:29	jonathanj	i guess they will appear on the stream in the order they were put so getting the order mixed up is probably unlikely, and anything else is probably application specific
13:36	jonathanj	hrm
13:45	jonathanj	i have a seq of strings ["a" "b" "c" "d"] i'd like to join all but the last with " " and the last with ": "
13:45	jonathanj	i'm not quite sure how to efficiently construct this, i'd also like to avoid using (count)
13:46	jonathanj	(interleave) and (repeat) seem like they might work but i'm not sure how to get the special case separator at the end
13:50	justin_smith	jonathanj: butlast / last?
13:50	oddcully	,(let [l ["a" "b" "c"]] (str (clojure.string/join " " (butlast l)) ": " (last l)))
13:50	clojurebot	"a b: c"
13:50	tmtwd	cider is giving me an error of input not complete and will freeze up
13:50	tmtwd	how do I quit the current "input"?
13:50	jonathanj	it probably doesn't actually matter for my case but i was trying to avoid those because they talk about linear time
13:51	justin_smith	jonathanj: then use a vector and peek and pop which are much faster
13:52	justin_smith	,(let [l ["a" "b" "c"]] (str (clojure.string/join " " (pop l)) ": " (peek l)))
13:52	clojurebot	"a b: c"
13:52	justin_smith	does not work with lazy-seqs, and does not work as you would expect with lists
13:53	oddcully	popl and peekl could be a cartoon show
13:53	jonathanj	justin_smith:great, that would work perfectly for my use case
13:56	tmtwd	(without restarting cider, that is)
13:56	justin_smith	tmtwd: C-cC-c should cancel the current input
13:56	tmtwd	justin_smith, :) thansk
14:00	justin_smith	jonathanj: of course creating a vector is linear time
14:00	jonathanj	justin_smith: i find myself wondering if there is a nice solution with lazy seqs without last/butlast
14:01	justin_smith	jonathanj: a recursive function on the lazy-seq could do it
14:02	justin_smith	it would involve testing if you are at the next-to-last item on each iteration, and using a stringbuilder if you want speed (or a bunch of intermediate strings if you don't care about speed)
14:05	tmtwd	Ah, for some reason cider-repl-kill-input just works for me
14:05	jonathanj	i keep forgetting this, but what is this command called: (x [1 2] [3 4]) => [[1 3] [2 4]]?
14:06	jonathanj	(in Python it's called zip)
14:06	oddcully	map vector would result in this
14:07	waynr	can anyone point to an example of using clj-logging-config to set logging configuration dynamically?
14:07	jonathanj	oddcully: ah, true, thank you
14:08	oddcully	but bet there is an easier way i forgot
14:09	amalloy	oddcully: nope
14:32	tmtwd	whats the proper way to define a regex string in clojure? (def the-string "\Q(youtu.be/\|youtube.com/(watch?(.*&)?v=\|(embed\|v)/))([^?&"'>]+)\E") . I'm trying this from a stackoverflow answer, I don't think it is correct though
14:32	tmtwd	I keep getting a unmatched delimiter error
14:35	amalloy	#""
14:35	clojurebot	It's greek to me.
15:27	justin_smith	tmtwd: there's an unescaped " in the middle of that regex
15:27	tmtwd	ah
15:27	justin_smith	also it's a string, and probably you want it to be an actuall regex (using the #"" syntax)
15:28	tmtwd	yes, in that example I forgot the # ----- there should be an app that inserts all the escape chars for you
15:29	tmtwd	and you can select whichever language you want outputted
15:29	justin_smith	tmtwd: there's an emacs mode that does it
15:29	tmtwd	which one?
15:29	justin_smith	one moment, have to look up the name (just remember my keybinding)
15:30	justin_smith	string-edit, it provides the command "string-edit-at-point"
15:30	tmtwd	ok will look into it
15:30	justin_smith	it opens the unescaped string in a new buffer, and when you hit C-cC-c it takes what's in the buffer, escapes it, and puts it back where your cursor was
15:30	justin_smith	also you can use it recursively
15:31	justin_smith	to escape a string inside an escaped string...
15:32	tmtwd	wow
15:32	tmtwd	sounds like a useful tool
16:04	magnars	justin_smith: I made string-edit, and I had never considered that you could use it recursively. Thanks ^^
16:40	justin_smith	magnars: haha
16:42	justin_smith	magnars: thanks for making string-edit btw, it's useful
16:43	magnars	just scratching my own itches - glad it's of help :-)
17:03	jonathanj	i'm writing an IRC client and the API i have at the moment is returning [send-command close-connection!] from the function that establishes the connection, the problem is that commands to reply to a message or say some text turn into something like (say send-command target msg) and i have to pass send-command around everywhere
17:04	jonathanj	in something like java or python, one might return some object that encapsulates a giant pile of state
17:04	jonathanj	is there an idiomatic clojure approach to this kind of problem?
17:09	tdammers	use closures?
17:10	wasamasa	jonathanj: perhaps https://github.com/stuartsierra/component
17:12	jonathanj	tdammers: could you elaborate?
17:13	jonathanj	tdammers: send-command is already a closure, it closes over the raw tcp stream and provides a slightly more high level api than "some bytes"
17:13	tdammers	ah, ok
17:13	jonathanj	tdammers: it's infeasible to provide a closure for every possible command that could ever be executed though
17:13	tdammers	I thought the question was "how do I wrap up a bunch of state in order to pass it around"
17:14	jonathanj	tdammers: it is that, except it's a level up
17:16	jonathanj	component looks like a possible solution, albeit quite a complicated one
17:17	wasamasa	it isn't complicated actually
17:17	wasamasa	just a pretty disciplined way to structure an application
17:17	jonathanj	maybe complicated wasn't the right word
17:17	wasamasa	if you take a look at the code, you'll notice it's nearly nothing
17:18	jonathanj	i guess i always thought of (defrecord) of giving up on a functional style
17:19	jonathanj	as giving up*
17:20	jonathanj	maybe that's just an extreme reaction?
17:21	wasamasa	perhaps
17:21	clojurebot	Excuse me?
17:21	wasamasa	I don't see anything wrong with them considering they're just another type of immutable data structure
17:22	jonathanj	there's also the "Notes for Library Authors" section, which seems pertinent
17:36	weebz	Does anyone know how to list an objects methods+properties in the CLR version on mono?
17:36	weebz	It doesn't seem like I'm able to use the typeof() function for some reason
17:46	weebz	Figured it out. (.GetProperties (type obj)) and (.GetMethods (type obj))
18:22	tmtwd	is is there a way to use callbacks in reagent , like I want to do in this example? http://pastebin.com/N3y0KSiu
18:23	justin_smith	tmtwd: that do is redundant
18:24	justin_smith	does create-new-contact do something async?
18:24	tmtwd	it just adds a contact to a database , but list-contacts (which renders the list) seems to be called before the contact is added
18:25	justin_smith	what kind of database?
18:25	tmtwd	oh, I suppose I could just call list-contacts in create-new-contact ---
18:25	justin_smith	is it a call to an api?
18:25	tmtwd	justin_smith, postgres via a local api
18:26	justin_smith	OK, then you should make sure the API gives you back its success result before you return from create-new-contact
18:27	justin_smith	or, if it's an AJAX call to the api, you can put (list-contacts) in the callback
18:27	justin_smith	or, you could use core.async
18:28	tmtwd	i see, I put in in (list-contacts), since it is an ajax call
18:35	oddcully	tmtwd: usually in react land you want to "react" on the change
18:35	oddcully	so request your modification in your button
18:35	tmtwd	okay
18:36	oddcully	but let some centract instance take care of the change
18:36	oddcully	once the change occurs, depending on your "storage" in the client, it should trigger the re-render of "everything"
18:36	tmtwd	centract?
18:36	oddcully	usually you have some watch on your actual data
18:36	justin_smith	oddcully: so you mean a component
18:37	oddcully	s/centract/concrete/
18:43	oddcully	hmm to bad, that word is already in use
18:43	oddcully	i had hoped i found a new one
20:00	domokato	i have a vector created with [] and I'm trying to add more elements to it using for, but instead it creates a sequence inside of the vector. Is there a way to pull the elements out of the sequence and put them into the vector?
20:03	oddcully	,(let [v []] (into v (for [i (range 3)] i)))
20:03	justin_smith	domokato: into
20:03	clojurebot	[0 1 2]
20:03	justin_smith	domokato: remember that vectors are immutable, so what's really happening is that conj or into returns a new vector that you have to use
20:03	domokato	ah, okay, but there's no way to do it somewhere like part way inside the vector, without breaking it up
20:04	justin_smith	domokato: no, vectors do not support inertion in the middle, you have to do something else (maybe concat)
20:05	domokato	oo okay, into or concat, thanks guys
20:07	justin_smith	,(let [v [:a :b :c :d :e]] (reduce into (subvec v 0 2) [[1 2 3 4] (subvec v 3 5)])
20:07	clojurebot	#<RuntimeException java.lang.RuntimeException: EOF while reading>
20:08	justin_smith	,(let [v [:a :b :c :d :e]] (reduce into (subvec v 0 2) [[1 2 3 4] (subvec v 3 5)]))
20:08	clojurebot	[:a :b 1 2 3 ...]
20:08	justin_smith	,(apply str (let [v [:a :b :c :d :e]] (reduce into (subvec v 0 2) [[1 2 3 4] (subvec v 3 5)])))
20:08	clojurebot	":a:b1234:d:e"
20:09	justin_smith	domokato: whatever you come up with, you'll likely find subvec helpful
20:09	amalloy	domokato: notably, there is no function to do it because it is impossible to do efficiently. if it's important for you to do it, you can still do so inefficiently, but you should usually reconsider whether vectors are the right data structure
20:10	justin_smith	excellent point
20:10	domokato	i'm trying to create an android layout using neko, which takes a vector
20:13	domokato	i think using concat i can preserve the order of ui elements in the code, for readability's sake
20:14	justin_smith	domokato: into does less work, if CPU becomes an issue
20:14	justin_smith	also concat returns a lazy-seq, not a vector
20:15	justin_smith	so you'll have the added cost of constructing a vector at the end, if the API needs a vector
20:15	justin_smith	unless you use into, which preserves the vector format
20:15	oddcully	depending on your work you are doing, there is also mapv
20:16	oddcully	(only for readability - in it's guts its into)
20:22	domokato	cool, gotcha
20:29	sdegutis	What's an admirable technique for getting the index of a given element in coll, and for getting an element by its index?
20:30	sdegutis	Ah, I see nth for the second part of my question.
20:31	sdegutis	I guess I can make do with map-indexed for the first part, if there's nothing better.
20:48	sdegutis	Hi.
20:54	jwm	hello
20:57	oddcully	hi
22:20	AWizzArd	I have an interface which I would like to reify. This interface has two methods `onFailure` that each take one arg. Those two methods are overloaded by type. How do I translate this into Clojure syntax?
22:21	justin_smith	AWizzArd: type hint the arguments in the declarations iirc
22:24	AWizzArd	Tried that. Got this error message: “Mismatched return type: onFailure, expected: void, had: java.lang.Object”
22:24	AWizzArd	Oh okay, seems I need to hint the return type as well.
22:25	justin_smith	makes sense I guess - in for a penny, in for a dollar?
22:30	oddcully	that is a good rule for any type system
22:45	sg2002	So, type hints work for reify? AFAIK they don't work for proxy.
22:47	waynr	can anyone recommend a function in clojure that will pretty print just the structure of a deeply nested data structure?
22:51	turbofail	what does the "structure" mean?
22:54	mistaBIZ	google'd to find "the arrangement of and relations between the parts or elements ..
22:54	waynr	i guess i mostly just don't want to look at all the dictionaries in each list since I know each dictionary has the same structure, i want to be able to see the entire structure at once so I can have confidence that i am accessing values correctly
22:56	mistaBIZ	as in how many branches of the tree it is in?
22:57	mistaBIZ	* 19:47
22:59	justin_smith	mistaBIZ: you could do a clojure.walk/postwalk that turns instances of map m into :my/m
23:00	justin_smith	,(require '[clojure.walk :as walk])
23:00	clojurebot	nil
23:02	justin_smith	,(require '[clojure.walk :as walk])
23:02	clojurebot	nil
23:02	justin_smith	,(walk/postwalk #({{:a 0 :b 1} :my/m} % %) [{:a 0 :b 1} {:x {:a 0 :b 1}} [:f {:z {:a 0 :b 1 :c {:a 0 :b 1}}}]])
23:02	clojurebot	[:my/m {:x :my/m} [:f {:z {:a 0, :b 1, :c :my/m}}]]
23:03	justin_smith	mistaBIZ: is that addressing what you want at all?
23:04	mistaBIZ	thats deep
23:04	justin_smith	mistaBIZ: it just finds all duplicates of a specific value and replaces them with a shorthand
23:45	rpaulo	\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\'