#clojure – 2015-05-30

2015-05-30

00:02	randomcharhere	One issue yeh will run into is if you change yer game object you will have change all the fuctions would create an itermediate function that talks to all the other functions that way yeh end only having to modify one fuction?
00:19	escherize	The best approach I've seen for managing a big-ass-state-map is re-frame, It's a clojurescript library that's got a simple idea that wouldn't be hard to implement in clojure.
00:27	dumptruckman	escherize: thanks, i'll look into it
00:27	dumptruckman	escherize: otherwise i basically have to deal with the big-ass-state-map yeah?
00:58	ambrosebs	where does lein repl call complete.core/completions?
00:59	ambrosebs	ah I think this is the code that gets injected https://github.com/trptcolin/reply/blob/69c4c6ffe0c8903a193c1e127337832e225335b0/src/clj/reply/reader/jline/completion.clj#L6-L7
02:32	escherize	dumptruckman: you might want to take a look at spectre for maintaining a big map if swap reset and update-in feel like not enough
03:26	elvis4526	I'm trying to use httpkit and websocket and with-channel isn't working.
03:26	elvis4526	within (with-channel req channel), channel is always nil.
07:28	ionthas_	dumptruckma: "It's better to have 100 functions operate in one datset insted of having 10 functions operating in 10 differents datasets." You should check atoms, they will allow to change the state of your big object. Maybe there is a better way to do it, but I'm also a principant.
07:34	irctc	what is the super class of map list String seq ...?
07:37	oddcully	Object?
09:16	franklnrs	join #bouncetest
09:20	gfredericks	irctc: "map list String seq ..." isn't a class?
10:34	virmundi	hello. Is there anyone active in here?
10:35	virmundi	I’ll give it a shot. I need to get a File from the tests/ dir of the project. I cannot figure out how to get that without handing a full path. I need a File and not a stream.
10:38	luxbock	virmundi: might (java.io.File. (.getCanonicalPath (java.io.File. ".")) "/tests/") work?
10:39	virmundi	let me see.
10:39	luxbock	(java.io.File. (str (.getCanonicalPath (java.io.File. ".")) "/tests/file.thing"))
10:40	virmundi	yes, yes it did. now I wonder why (io/file didn’t)
10:41	luxbock	replacing java.io.File. with io/file should work exactly the same
10:41	justin_smith	luxbock: isn't that the same as (java.io.File. "./tests/") - it should be
10:41	virmundi	I added a new resources directory under test and updated the lein profiles.clj to work.
10:42	luxbock	justin_smith: oh right!
10:42	virmundi	you’re right. tempfile2 (io/file "./test/resources/20150429_102332.jpg")
10:42	virmundi	thanks
10:43	justin_smith	virmundi: here's another neat trick --
10:43	justin_smith	,(java.io.File. "foo" "bar")
10:43	clojurebot	#object[java.io.File 0x1a442294 "foo/bar"]
10:43	justin_smith	no need to use str either :)
10:44	virmundi	:)
10:48	gfredericks	,(java.io.File. "foo/bar" "baz/kabling")
10:48	clojurebot	#object[java.io.File 0x3bd2c1b4 "foo/bar/baz/kabling"]
10:58	drivercache	Should i learn java before learning clojure?
10:58	drivercache	I am new.
10:58	SagiCZ	drivercache: not super necessary i would say
10:58	virmundi	no. As a guy who literally has a Java ring on as I type this, you don’t need it.
10:58	virmundi	http://s.hswstatic.com/gif/digital-jewelry-javaring.jpg
10:58	SagiCZ	drivercache: may help to read up about the very basics.. but you dont need to dive deep into inheritence, oop etc
10:59	justin_smith	drivercache: it suffices to know just enough so that javadoc is readable - you really don't need to get the syntax, but the semantics are helpful
11:00	virmundi	drivercache: the viewpoints are different. you can write clean code in java with out concern for much mutation (final for all vars), but clojure makes the same easier.
11:00	SagiCZ	virmundi: not entirely true.. its not as simple as slapping final on attributes.. clojure goes a long way towards immutability
11:00	virmundi	I agree. I was just saying.
11:00	justin_smith	virmundi: well... a final collection is still mutable, even if its field is final - so you do need immutable collections
11:01	SagiCZ	i think there are some java libraries for immutable collections.. probably not as efficient as in clojure
11:01	justin_smith	SagiCZ: clojure is a good java lib for immutable collections :)
11:02	virmundi	justin_smith: I’m saying you can do it in Java, but you’re going to get into some niche corners of Java development. Heck, using final is so odd for most developer I’ve been actually told to remove them because they make the code harder to read.
11:02	SagiCZ	justin_smith: interesting point! maybe some java coders could only use that part of clojure
11:02	SagiCZ	virmundi: seriously? thats just non-sensical, who told you that? final is appropriate in many cases and it may make the code way faster
11:03	virmundi	sagicz: a very poor programmer during a code review. I ignored her and then had a 20 minute conversation about code quality with the project manager.
11:04	SagiCZ	virmundi: i see!
11:04	SagiCZ	anyways whats up with clojure lately? is it still being developed? where is 1.7.0? is clojure losing momentum?
11:04	virmundi	sagicz: in the end, I got to keep the finals.
11:05	justin_smith	SagiCZ: 1.7 has a release cantidate, and might be the most feature rich addition we've had in a long while
11:05	justin_smith	might be comparable to the 1.2 -> 1.3 update
11:06	SagiCZ	justin_smith: and would you call clojure's future bright? i understand it will never become mainstream engine, but it needs to have a solid community so it wont die out. I hate to start a big project only to find that the tools I use get deprecated in the next year
11:06	SagiCZ	s/engine/language
11:06	justin_smith	I don't see any signs of that myself
11:07	SagiCZ	this is interesting though https://www.google.cz/trends/explore#q=clojure%2C%20golang&cmpt=q&tz=
11:07	SagiCZ	keyword trend comparison
11:08	SagiCZ	justin_smith: anyways, thanks.. thats mostly what i wanted to hear
11:08	justin_smith	clearly, if we want it to succeed, cognitect has to hand clojure over to bing
11:09	justin_smith	SagiCZ: I think the mailing list (available on google groups) gives a good idea of the state of development (both for the language and libs) - things tend to get announced or decided there
11:10	SagiCZ	justin_smith: i see.. well being quite young and from a Windows background I always found mailing-list bizzare and unproductive communication of the past.. almost like using mailing pidgeons.. so I guess thats why I didnt catch the latest development. thanks
11:11	justin_smith	SagiCZ: the UI on google groups makes it more like a web forum
11:11	SagiCZ	btw cognitect? is clojure developed by private company now<
11:11	SagiCZ	?
11:11	justin_smith	SagiCZ: always has been
11:11	justin_smith	it accepts contributions
11:12	SagiCZ	didn't know that
11:12	justin_smith	that's why you have to sign the super official agreement and use jira if you want to submit code for clojure
11:13	SagiCZ	well I don't think it's a bad idea at all..
11:13	SagiCZ	seems like clojure's development is fueled by Datomic and other cognitect products
11:13	justin_smith	they also offer clojure consulting
11:20	drivercache	SagiCZ: I have working knowledge of python, will it be enough to begin?
11:21	SagiCZ	drivercache: nothing is enough to begin
11:21	SagiCZ	if you learned python, you can learn clojure
11:21	SagiCZ	just note that functional programming is very different from imperative (python) and the transition might be difficult at first
11:25	gfredericks	hello
11:30	virmundi	hi
11:31	luxbock	I have a debug-printing helper library that currently just formats text nicely and prints it to the REPL
11:32	luxbock	I thought it might be a good idea to offer alternative output targets
11:32	justin_smith	luxbock: you should check out aviso/pretty and aviso/tracker
11:32	justin_smith	for prior art
11:32	luxbock	i.e. you could print to a file, create a HTML page or an org document
11:32	luxbock	justin_smith: this is mine: https://github.com/luxbock/pr-foobar
11:32	luxbock	I think they do different things
11:33	justin_smith	pretty is for things like column alignment and colors
11:33	justin_smith	tracker is for being able to show a context for errors that makes sense for clojure code
11:33	luxbock	my goal is that switching from the core-function to the pr-equivalent should be as painless as possible
11:33	justin_smith	OK
11:34	luxbock	so to switch the output function, I was thinking of making a dynamic variable that holds it
11:34	luxbock	and then just use alter-var-root to change it
11:34	luxbock	is this a good idea?
11:34	justin_smith	if you are using alter-var-root, why make the var dynamic?
11:34	luxbock	ah yeah I guess I wouldn't need to
11:43	virmundi	what am I doing wrong here: (io/copy (:tempfile file) dest-file)
11:43	virmundi	(:tempfile is a valid file). dest-file is a new file.
11:44	SagiCZ	:tempfile cant be a valid file, it is a keyword
11:44	virmundi	file is a map
11:44	virmundi	(:key m) == value?
11:44	SagiCZ	yes that is correct
11:45	virmundi	dest-file is new. But I’m getting a error actual: java.io.FileNotFoundException: /Users/jdavenpo/Pictures/tours/usa/fl/palatak/uuid/newfile.jpg
11:46	SagiCZ	well.. seems like the fild is not on that path
11:49	virmundi	(is (.exists tempfile))
11:49	virmundi	where tempfile is the value in the map :tempfile
11:49	SagiCZ	that returns true?
11:49	virmundi	yep
11:49	SagiCZ	you can lose the "is" btw
11:50	virmundi	the temp file is classpath relative.
11:50	virmundi	I can in a test?
11:50	SagiCZ	no no.. not in a test
11:50	SagiCZ	sorry
11:50	virmundi	np.
11:50	SagiCZ	tahts really weird.. because the jvm can access the file but then says its not found? strange
11:50	virmundi	The error is the new file.
11:51	SagiCZ	oh..
11:51	virmundi	(defmethod move :tour-list [file]
11:51	virmundi	(let [dest (create-dest file)
11:51	virmundi	dest-file (io/file dest)]
11:51	virmundi	(io/copy (:tempfile file)
11:51	virmundi	(io/file dest))
11:51	virmundi	dest))
11:51	SagiCZ	then maybe then you dont have write acces on the path
11:51	justin_smith	virmundi: don't do that please
11:51	virmundi	sorry, best way to do that?
11:51	SagiCZ	www.refheap.com
11:51	justin_smith	use a site like refheap
11:51	justin_smith	yeah
11:51	virmundi	https://www.refheap.com/101885
11:53	virmundi	the blow out is on line 5, as per the refheap
11:53	virmundi	the declaration at line 3 is for debugging.
11:53	SagiCZ	virmundi: would like to help you but i rly dont know whats wrong there
11:54	Chousuke	does the directory structure exist+
11:54	Chousuke	?
11:54	virmundi	:(
11:54	Chousuke	File won't automatically create you directories.
11:54	SagiCZ	yeah all the folders must exist before creating a new file
11:55	justin_smith	there's a method that creates all the nested folders you need for a given path though iirc
11:56	virmundi	.mkdir executes without creating the paths.
11:56	justin_smith	.mkdirs
11:57	justin_smith	"Creates the directory named by this abstract pathname, including any necessary but nonexistent parent directories."
11:57	justin_smith	you were missing the plural s
11:57	justin_smith	.mkdir only creates a single directory, where the parent must already exist
11:58	justin_smith	.mkdirs creates all the directories needed fora given file
11:58	virmundi	:O
12:04	virmundi	so then maybe a bit of Java is required for Clojure?
12:04	justin_smith	virmundi: like I said, you should at least know how to read the javadoc
12:05	justin_smith	but that's not java - you're not using java syntax. But we use the same vm and the same methods, so that ends up being something you should at least know how to look up.
12:06	virmundi	;)
12:06	virmundi	That was it.
12:06	virmundi	I had to get the parent dir of the new file, but worked fine.
12:06	virmundi	thanks
12:07	justin_smith	virmundi: I find the "javadoc search pane" browser plugin really useful
12:08	justin_smith	it detects when you are looking at a javadoc page, and makes a pane with real-time completion and search
12:08	SagiCZ	i would rather see the javadoc in my IDE than having to switch to browser
12:09	justin_smith	SagiCZ: I don't want to read javadoc in emacs myself
12:09	SagiCZ	i understand..
12:10	SagiCZ	i am very sensitive to my tool chain and i understand others may be as well so that can be left for personal preference
13:13	luxbock	one thing I've started doing lately with destructuring is to always use :as even when it's not strictly needed
13:13	luxbock	but I think it makes it easier to read the code, because the name can give a hint to what the argument/local is supposed to do
13:13	luxbock	anyone else do this?
13:21	gfredericks	I don't because it looks like a mistake
13:22	gfredericks	but I appreciate the desire for documentation
13:22	gfredericks	clojure currently conflates the local names of args with documentation for the args
13:22	justin_smith	see also using prismatic/schema but not running the checks
13:22	justin_smith	but using the declarations as a form of docs
13:23	gfredericks	I wish there were a standard way to add arg documentation
13:23	justin_smith	yeah, exactly
13:23	justin_smith	metadata on args?
13:23	gfredericks	the drawback is
13:23	luxbock	gfredericks: ditto
13:23	gfredericks	you sometimes have multiple arglists
13:23	gfredericks	which might be irrelevant to the documentation
13:23	gfredericks	,(doc +)
13:23	clojurebot	"([] [x] [x y] [x y & more]); Returns the sum of nums. (+) returns 0. Does not auto-promote longs, will throw on overflow. See also: +'"
13:24	justin_smith	gfredericks: first class code accessible arglist objects, with first class code accessible arg objects
13:24	gfredericks	what
13:24	justin_smith	so you could do like (-> #'+ :arglists first :args first :doc)
13:24	justin_smith	never mind that's crazy
13:25	gfredericks	I would suggest :doc/args metadata on the var
13:25	gfredericks	related, you could also add examples as metadata
13:25	gfredericks	i.e., as first-class code rather than in a docstring
13:25	gfredericks	which could additionally be subject to automatic validation
13:25	justin_smith	tests can already be specified this way
13:26	gfredericks	yeah
13:26	gfredericks	well
13:26	gfredericks	sort of
13:26	gfredericks	,(doc test)
13:26	clojurebot	"([v]); test [v] finds fn at key :test in var metadata and calls it, presuming failure will throw exception"
13:26	gfredericks	^ it looks for a fn, not a form
13:26	justin_smith	ahh
13:26	justin_smith	yeah that is different
13:27	gfredericks	and you have to throw exceptions :/
14:11	gfredericks	does anybody know an elisp way to check if the current buffer is a file that is in the project that the default cider connection is a part of?
14:11	gfredericks	I assume any solution has to be super hacky
14:12	clojer	I have a (let .... form containing 2 non-nested (for ... comprehensions. Only the last one seems to execute even if I wrap them both in a (do ... block which shouldn't be necessary in a (let ... form.
14:17	justin_smith	~for
14:17	clojurebot	for is a beautiful person
14:18	justin_smith	clojer: sorry, I wanted a different factoid. for is lazy
14:18	justin_smith	use doseq if you are not consuming the result
14:18	justin_smith	it's almost identical, but returns nil and is not lazy
14:18	justin_smith	,(do (for [a (range 10)] (println a)) nil)
14:18	clojurebot	nil
14:19	clojer	justin_smith: Why does only the last for comp execute?
14:19	justin_smith	,(do (doseq [a (range 10)] (println a)) nil)
14:19	clojurebot	0\n1\n2\n3\n4\n5\n6\n7\n8\n9\n
14:19	justin_smith	clojer: laziness
14:19	justin_smith	notice the difference between what for and doseq did above
16:05	fourq	I'm reading up on persistent vectors and their inner workings. If someone could speak to this image, specifically what it means when it says "path copying". The way I interpret this is that the new vec, the blue one, created 3 new internal nodes, 1 new leaf node, and then pointed the left internal node to the existing, old, vector. Where does "path copying" come into play here? http://screencast.com/t/ZG4igyaPHS7
16:25	bmorphism	Is output-stream with lazy-seq the solution if I want to output the results of a computation into a file and not keep them in memory?
17:21	underplank	So I have this (def scripts-path (str (io/resource "test/scripts") "/"))
17:21	underplank	which gives me "file:/Users/mlakewood/Projects/orochi/resources/test/scripts/"
17:21	underplank	hoe do I get just the string representation without the file: on there
17:22	underplank	*how
17:28	justin_smith	underplank: (.getPath (io/resource "test/scripts"))
17:28	justin_smith	you don't need to add the / yourself
17:29	underplank	Oh great! I’d worked out that I needed to get a java url and then do getPath on it.. but didnt realise that I could just call getPath on the return. Makes sens.
17:29	underplank	thanks justin_smith helpful as always!
17:42	jtmarmon	hey guys
17:43	jtmarmon	i have a fairly large threaded macro that fails macro expansion whenever I add "..." to one of the forms...if i remove it it succeeds. the compilation error is "CompilerException java.lang.StringIndexOutOfBoundsException: String index out of range: 0"
17:43	jtmarmon	just having ... anywhere in the macro makes it fail with that error. it's quoted just fine as far as i can tell. super weird
17:44	justin_smith	wait, what does 'add "..." to one of the forms' mean exactly?
17:44	justin_smith	like one of the forms has "..." in it?
17:44	justin_smith	the string?
17:44	jtmarmon	yep
17:44	jtmarmon	no
17:44	jtmarmon	the characters ...
17:44	jtmarmon	not in a string
17:44	jtmarmon	the form is quoted
17:45	justin_smith	even if quoted, I don't think ... is valid - it's not a valid symbol or symbol constituent. There may be contexts where it works accidentally.
17:45	justin_smith	,'...
17:45	clojurebot	...
17:46	jtmarmon	it's for a datomic collection binding
17:46	justin_smith	OK
17:46	justin_smith	funny, ... actually works as a symbol, but I didn't expect it to
17:47	jtmarmon	http://puu.sh/i6pA9/97aa45aa3f.png
17:50	TEttinger	,(let [... "wat"] ...)
17:50	clojurebot	#error {\n :cause "Illegal field name \"...\" in class sandbox$eval49"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.ClassFormatError: Illegal field name \"...\" in class sandbox$eval49, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyzeSeq "Compiler.java" 6740]}\n {:type java.lang.ClassFormatError\n :message "Illegal field name \"...\" in ...
17:50	TEttinger	hm
17:50	justin_smith	,(def ... "this works")
17:50	clojurebot	#'sandbox/...
17:51	justin_smith	,...
17:51	clojurebot	"this works"
17:51	TEttinger	whaaaaat
17:51	justin_smith	TEttinger: yeah, I know, right?
17:51	justin_smith	that's why my first instinct was that it only worked accidentally
17:51	TEttinger	(inc wat)
17:51	lazybot	⇒ 3
17:51	TEttinger	how doe sthat have 3
17:51	justin_smith	TEttinger: I think it's because vars are not used as method or field names
17:52	justin_smith	TEttinger: if only our incs left metadata we could look up on the karma :)
17:52	TEttinger	haha
17:52	TEttinger	lazybot could even dump to refheap
17:56	justin_smith	,(def watset (hash-set Double/NaN Double/NaN Double/NaN))
17:56	clojurebot	#'sandbox/watset
17:56	justin_smith	,watset
17:56	clojurebot	#{NaN NaN NaN}
17:56	justin_smith	,(get watset Double/NaN)
17:56	clojurebot	nil
17:56	justin_smith	,(get watset (first watset))
17:56	clojurebot	NaN
17:56	justin_smith	roflmao
18:02	justin_smith	,(= watset (hash-set Double/NaN Double/NaN Double/NaN))
18:02	clojurebot	false
18:02	justin_smith	,(= watset (apply hash-set watset))
18:02	clojurebot	true
18:02	TEttinger	haha
18:02	TEttinger	,(count watset)
18:02	clojurebot	3
18:03	TEttinger	,(distinct watset)
18:03	clojurebot	#<UnsupportedOperationException java.lang.UnsupportedOperationException: nth not supported on this type: PersistentHashSet>
18:03	TEttinger	oh?
18:03	justin_smith	,(distinct (seq watset))
18:03	clojurebot	(NaN NaN NaN)
18:03	TEttinger	,(distinct (seq watset))
18:03	clojurebot	(NaN NaN NaN)
18:03	TEttinger	haha
18:03	justin_smith	TEttinger: it's like we found the weirdest insect ever under a rock, and now we just can't stop poking it
18:03	TEttinger	haha
18:04	justin_smith	let's see what it does if we put it in a jar with a spider
18:04	TEttinger	I was going to link to a solifugid, but oh god those things are terrifying
18:05	justin_smith	is that the same as a camel spider?
18:05	TEttinger	here's a better weird bug, it's nice https://flic.kr/p/cu62MQ
18:05	TEttinger	not sure
18:06	TEttinger	I think sun spiders
18:06	justin_smith	$google solifugid
18:06	TEttinger	I don't like house centipedes for totally different reasons
18:06	lazybot	[Solifugae - Wikipedia, the free encyclopedia] http://en.wikipedia.org/wiki/Solifugae
18:06	justin_smith	"known variously as camel spiders, wind scorpions, sun spiders, or solifuges"
18:06	TEttinger	(as in, if you hit a house centipede with, say, your shoe, its legs fly off and KEEP MOVING)
18:06	justin_smith	heh
18:07	justin_smith	very similar in nature to a set full of multiple NaNs
18:07	TEttinger	yes
18:07	TEttinger	it is what should not be
18:55	sdegutis	Is there anything Clojure can't do that Haskell can, aside from the restrictions and type-checking errors Haskell provides?
18:56	gfredericks	it's probably easier to call C code in haskell?
18:57	sdegutis	Okay but any algorithmic type things?
18:57	sdegutis	Like, can Clojure implement monads?
19:01	justin_smith	there are monadic libraries for clojure, but since we don't have easy type inference or strong type requirements they usually don't end up being especially useful
19:05	sdegutis	Ah I see.
19:06	sdegutis	Thanks guys.
19:06	sdegutis	Welp, back to cleaning up the mess I made in our codebase at work.
19:06	gfredericks	sdegutis: actually yeah monads are a good point -- you can't straightforwardly write polymorphic 0-arg functions that monads in haskell depend on
19:07	gfredericks	I think this is the main reason why trying to write a monad library in clojure is pretty awkward
19:08	justin_smith	gfredericks: even using one is a bit weird
19:08	gfredericks	I've never tried
19:09	sdegutis	gfredericks: Oooh, that explains it.
19:09	sdegutis	Because in Clojure, polymorphism requires at least one argument.
19:09	gfredericks	yep
19:09	sdegutis	In Haskell, it can be based on type, which is like an implicit argument almost.
19:09	gfredericks	can't write (return x) or (pure x) or whatever
19:09	sdegutis	Got it.
19:09	gfredericks	so you could A) require everybody to pass "the monad" around, in which case nobody will want to use your library
19:10	gfredericks	B) do something magical with macros or dynamic vars or something, in which case nobody will want to use your library
19:10	gfredericks	C) don't bother writing a monads library, in which case nobody will want to use your library
19:11	gfredericks	if bbloom were here he would argue that monads aren't very useful anyhow
19:11	bbloom	just use a lazy seq and write an interpreter for that seq w/ reduce
19:12	sdegutis	Oooh, of course!
19:12	sdegutis	bbloom: why not transducers?
19:12	gfredericks	he didn't say not transducers
19:12	sdegutis	bbloom: I was under the impression that transdocers completely obsolete your solution.
19:12	sdegutis	gfredericks: I thought transducers and lazy seqs were incompatible?
19:13	gfredericks	not at all
19:13	bbloom	s/lazy seq/whatever-ducable/
19:13	gfredericks	,(doc sequence)
19:13	clojurebot	"([coll] [xform coll] [xform coll & colls]); Coerces coll to a (possibly empty) sequence, if it is not already one. Will not force a lazy seq. (sequence nil) yields (), When a transducer is supplied, returns a lazy sequence of applications of the transform to the items in coll(s), i.e. to the set of first items of each coll, followed by the set of second items in each coll, until any one of the co...
19:14	gfredericks	hmm
19:14	gfredericks	,(sequence (map inc) [1 2 3])
19:14	clojurebot	(2 3 4)
19:14	gfredericks	,(type (sequence (map inc) [1 2 3]))
19:14	clojurebot	clojure.lang.LazySeq
19:14	gfredericks	,(sequence (map inc) (range 5))
19:14	clojurebot	(1 2 3 4 5)
19:14	gfredericks	^ lazy seq in, lazy seq out, w/ transducers
19:15	gfredericks	did refinements ever make it to ruby 2?
19:20	sdegutis	I think I prefer objects, classes, and dot-notation.
19:20	gfredericks	you've been saying that for weeks now I think
19:20	sdegutis	I have? I thought this was the first time.
19:20	gfredericks	okay I'll stop conversing I guess
19:21	sdegutis	wat
19:22	sdegutis	I don't see the connection from everything before that to that.
19:23	gfredericks	I assumed you were trolling because most of your conversation lately has been about OOP
19:28	gfredericks	I was tripped up by the difficulty of telling intentions via text; my apologies
19:29	sdegutis	:\|
19:34	sdegutis	I guess I'm just coming to this same conclusion over and over because I've made a mess of my codebase by trying to design our system with just pure functions, which has a lot of drawbacks.
19:39	gfredericks	how much legacy ruby have you dealt with?
19:40	sdegutis	gfredericks: plenty
19:40	sdegutis	gfredericks: I'd say this is worse.
19:43	sdegutis	Neat how in Datomic a bool value can be true false or nil.
19:44	sdegutis	I am taking advantage of that right now in my code.
23:35	dumptruckman	how do i join together lists into one list?
23:35	justin_smith	dumptruckman: concat
23:35	dumptruckman	ah, thanks
23:36	justin_smith	,(concat (range 3) (range 3))
23:36	clojurebot	(0 1 2 0 1 ...)
23:38	dumptruckman	is there some way to do this with destructuring?
23:38	dumptruckman	(concat (for [player (:players entites)] (:segments player)))
23:38	justin_smith	no
23:39	justin_smith	I mean there is apply concat
23:39	dumptruckman	actually i'm not even sure that's right >.>
23:39	justin_smith	or mapcat
23:39	justin_smith	,(apply concat (for [a {:a [0 1]} {:a [:b :c]}] (:a a)))
23:39	clojurebot	#error {\n :cause "for requires an even number of forms in binding vector in sandbox:"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.IllegalArgumentException: for requires an even number of forms in binding vector in sandbox:, compiling:(NO_SOURCE_FILE:0:0)"\n :at [clojure.lang.Compiler macroexpand1 "Compiler.java" 6644]}\n {:type java.lang.IllegalArgumentExce...
23:39	justin_smith	err
23:39	clojurebot	I don't understand.
23:40	justin_smith	,(apply concat (for [a [{:a [0 1]} {:a [:b :c]}]] (:a a)))
23:40	clojurebot	(0 1 :b :c)
23:40	justin_smith	(mapcat :a [{:a [0 1]} {:a [:a :b]}])
23:40	justin_smith	,(mapcat :a [{:a [0 1]} {:a [:a :b]}])
23:40	clojurebot	(0 1 :a :b)
23:40	dumptruckman	wait
23:40	dumptruckman	apply concat?
23:40	justin_smith	mapcat is likely the one you want
23:40	dumptruckman	i see
23:41	justin_smith	but apply concat works too
23:41	justin_smith	mapcat is just apply concat map ...
23:41	justin_smith	$source mapcat
23:41	lazybot	mapcat is http://is.gd/HgriSd
23:41	dumptruckman	i see
23:45	dumptruckman	when i'm defining a map is it possible to refer to the values i've defined ahead of another?
23:46	justin_smith	sounds like something where a let block plus a few calls to assoc would help
23:46	TEttinger	dumptruckman: you can use ##(declare)
23:46	lazybot	⇒ nil
23:46	TEttinger	dumptruckman: you can use ##(doc declare)
23:46	lazybot	⇒ "Macro ([& names]); defs the supplied var names with no bindings, useful for making forward declarations."
23:46	dumptruckman	O.o
23:46	dumptruckman	for instance
23:46	TEttinger	,(declare foo)
23:46	clojurebot	#'sandbox/foo
23:47	TEttinger	,{:bar foo :a 1}
23:47	clojurebot	{:bar #object[clojure.lang.Var$Unbound 0x7c02c5a4 "Unbound: #'sandbox/foo"], :a 1}
23:47	TEttinger	,(def mapperz {:bar foo :a 1})
23:47	clojurebot	#'sandbox/mapperz
23:47	TEttinger	,(def foo "yay")
23:47	clojurebot	#'sandbox/foo
23:47	TEttinger	,mapperz
23:47	clojurebot	{:bar #object[clojure.lang.Var$Unbound 0x7c02c5a4 "Unbound: #'sandbox/foo"], :a 1}
23:47	TEttinger	hm
23:47	dumptruckman	{:a a :b b :c :a} where the value for c is the value for :a
23:47	TEttinger	oh
23:47	justin_smith	yeah, use assoc for that
23:48	justin_smith	,((fn [m] (assoc m :c (:a m))) {:a 0})
23:48	clojurebot	{:a 0, :c 0}
23:49	dumptruckman	meh
23:49	dumptruckman	i think that's probably more complicated than juts putting the value again
23:49	justin_smith	dumptruckman: if you already knew the value, do that
23:49	TEttinger	or you could have it be a key into a different table
23:49	justin_smith	I thought you were talking about a situation where the caller could specify any :a they please, and you need to map :c to that too
23:50	dumptruckman	nah
23:50	dumptruckman	i'm defining a player object which has a color key
23:50	dumptruckman	and also needs to define a shape in the same map using that color
23:50	dumptruckman	it might be useful later
23:50	dumptruckman	when i get to having more than 1 player
23:50	TEttinger	,(let [inner {:a 10 :b 20} outer {:a :a :b :b :c :a}] (inner (outer :c)))
23:50	clojurebot	10
23:51	dumptruckman	wat
23:54	dumptruckman	i can't wrap my mind around that
23:56	dumptruckman	hmm
23:56	dumptruckman	this doesn't seem to be doing what i'm going for
23:56	dumptruckman	(apply concat (for [player (:players entities)] (:segments player)))
23:57	justin_smith	dumptruckman: equivalent is (mapcat :segments (:players entities))
23:57	justin_smith	and I think that version is a bit nicer
23:57	dumptruckman	well
23:57	dumptruckman	it produces an empty lits
23:57	dumptruckman	but there's definitely something in the segments part that i'm trying to retrieve
23:58	dumptruckman	so entities is a map that has a seq of :players and each element of that seq has a seq of :segments
23:59	justin_smith	so (-> entities :players first :segments) will always give you a seq
23:59	justin_smith	if so, that for comprehension should work