#clojure – 2012-08-04

2012-08-04

01:09	Frozenlo`	Is there clojure/clojurescript libraries to simulate mechanical or electrical systems? (à la Bret Victor would be nice)
01:57	Bastianx9	\|\| Paypal Account Full Information \|\| Payment Method Liberty Reserve Only \|\| Paypal Account Full Information \|\| Payment Method Liberty Reserve Only \|\| Paypal Account Full Information \|\| Payment Method Liberty Reserve Only \|\|
02:16	mdeboard	itext is the worst.
02:19	aperiodic	you mean that PDF parsing library?
02:40	mritz	whats the best way to have leon 1 and 2 both installed
02:40	mritz	is there like a virtual environment ?
02:42	eggsby	why not just have lein and lein2 in your $PATH ?
02:47	amalloy	mritz: just install them both, that's all there is. give the two scripts different names
02:50	mritz	amalloy: Thanks! that worked
04:20	leafw	hi all. If I have an int like (bit-shift-left 255 24), and I want to store it in an array of primitive ints, how can I cast it to signed int to do so? Clojure, righly so, complains that it can't be casted because it is out of range
04:21	leafw	i.e. how to store an unsigned int 0xff000000 in a java primitive int, which is signed?
04:31	pyrtsa	leafw: Don't know of a direct way, but this works for 32 bit: (defn int* [x] (let [i (bit-and 0x7fffffff x)] (Integer. (if (< x 0x8000000) x (+ -0x80000000 i)))))
04:32	leafw	pyrtsa: thanks. I am hoping there is a better way, for example casting to int at the right places within bit-and, bit-or, etc.
04:32	leafw	otherwise performance will suffer lots
04:33	pyrtsa	Like I said, I don't know of any. :/
04:35	leafw	,(byte 0xff)
04:35	clojurebot	#<IllegalArgumentException java.lang.IllegalArgumentException: Value out of range for byte: 255>
04:35	leafw	that made no sense to me
04:35	leafw	so clojure considers hexadecimal not as bits filled in but as actual numbers
04:39	hyPiRion	leafw: Makes perfect sense
04:39	hyPiRion	,0xff
04:39	clojurebot	255
04:39	leafw	hyPiRion: so what is the right way to do bit-wise math in clojure?
04:40	amalloy	leafw: there is no such thing as unsigned on the jvm
04:40	leafw	how to pack 4 bytes into one int?
04:40	leafw	mind giving an example?
04:40	leafw	amalloy: I am aware. In the java side, one always masks first to 0xff
04:40	hyPiRion	leafw: ##(ubyte 0xff)
04:41	lazybot	java.lang.RuntimeException: Unable to resolve symbol: ubyte in this context
04:41	hyPiRion	oh, its name is something else, lemme check it up
04:44	leafw	no suggestions in the clojure cheatsheet for byte similar to ubyte
04:44	mdeboard	Did I reinvent the wheel here https://gist.github.com/3256063
04:45	raek	leafw: unchecked-bit-shift-left
04:45	mdeboard	wrt metadata on proxies
04:45	hyPiRion	,(unchecked-byte 0xff)
04:45	clojurebot	-1
04:45	hyPiRion	,(unchecked-byte 0xffff)
04:45	clojurebot	-1
04:45	leafw	aha
04:45	leafw	thanks
04:45	leafw	so the unchecked math is what will do it
04:46	leafw	thanks a lot!
04:46	hyPiRion	no problem, it's hard to find
04:46	leafw	the cheatsheet doesn't list the bit-wise ops under the unchecked section
04:51	leafw	raek: Unable to resolve symbol: unchecked-bit-shift-left in this context
04:51	leafw	raek: so unchecked math must be invoked in a binding or something line that
04:52	raek	leafw: hrm, that functions does not exist, but other unckecked version for other operators do
04:53	raek	you can always do this: (unchecked-int (bit-shift-left 255 24))
04:54	raek	'unchecked-int' works as (int) in java (it throws away all but the 32 lowest bits)
04:54	amalloy	mdeboard: i think you may have just reinvented being crazy
04:54	leafw	,(unchecked-int (bit-shift-left 255 24))
04:54	clojurebot	-16777216
04:54	leafw	good!
04:54	leafw	thanks raek
04:55	amalloy	like, ignoring whether proxy is the right answer ( i don't know what a PdfReader is, these implementations of the meta functions don't make sense
04:55	raek	I'm not totally sure how unchecked-math is used
04:55	leafw	lack of examples hinders it suse
04:55	raek	I think you are supposed to 'set!' it before you eval the defns or something
04:55	leafw	google is full of past examples, but unchecked math has changed lots over time
04:56	leafw	there is a math-context for with-bindings
04:56	leafw	http://clojuredocs.org/clojure_core/clojure.main/with-bindings
04:56	leafw	without an explanation on what it is for
05:37	leafw	I got the bit-wise math to work. In short, to imitate the java side of things with truncating primitives, one has to use unchecked-long (the only kind of cast that doesn't result in a reflection warning when using bit-or, bit-and, etc.)
05:37	leafw	all bit-wise operators are used as normally one would.
05:38	leafw	and it is true that operations on primitive types return primitives: no boxing warnings
05:40	leafw	suprisingly one gets boxing warnings when feeding byte, short, or int into bit-and, for example. Only a long would avoid the reflection warning.
05:41	leafw	I'd asume that byte/short/int would automatically promote to long
05:44	alexyakushev	What is the best exception to throw if macro was used incorrectly (wrong number of arguments, for instance)?
05:45	hyPiRion	Exception.
05:45	hyPiRion	It kind of depends, though. Do you want it to be compile-time or runtime?
05:45	alexyakushev	Compile time, I guess
05:46	leafw	the good news is that bit-or with more than 2 arguments runs at the same speed as an unrolled set of bit-or's
05:47	hyPiRion	Then go with Exception. Runtime should be RuntimeException
05:47	alexyakushev	And what about this "CompilerException java.lang.RuntimeException" Clojure uses for symbols not resolved?
05:52	hyPiRion	,foo
05:52	clojurebot	#<CompilerException java.lang.RuntimeException: Unable to resolve symbol: foo in this context, compiling:(NO_SOURCE_PATH:0)>
05:52	hyPiRion	,(doc resolve)
05:52	clojurebot	"([sym] [env sym]); same as (ns-resolve ns symbol) or (ns-resolve ns &env symbol)"
05:53	hyPiRion	bleh
05:53	hyPiRion	,(source resolve)
05:53	clojurebot	Source not found
05:55	hyPiRion	Ah, resolve is a runtime error, but I don't know about CompilerException. It's not the compiler there's some issue with when you're using the wrong number of arguments.
05:55	hyPiRion	,(let [foo (fn [] (resolve 'bar))] nil)
05:55	clojurebot	nil
05:55	hyPiRion	,(let [foo (fn [] (resolve 'bar))] (foo))
05:55	clojurebot	nil
05:57	alexyakushev	OK, thank you. Exception will do
06:00	hyPiRion	Clojure isn't all that into Java-exceptions as far as I get it - it's better to have a descriptive error message.
08:51	hcumberdale	;)
08:52	hcumberdale	My blog in clojure is finished ;)
09:09	horofox	hcumberdale: share it.
10:51	pandeiro	is there a good reason that predicate functions should only return true or false/nil? i find myself creating pseudo-predicates that return a val or nil; is that a bad pattern?
10:53	duck1123	I think it depends on the predicate fn, a lot of them return the val for truthy
10:54	cshell	seems more robust to return the val or nil
10:56	duck1123	of course, sometimes writing it to return the val may make that predicate slower. In both cases you'd have the test, but if you want to return the value, you'd need an if and then return the input
10:57	duck1123	(fn [x] (> x 7)) vs (fn [x] (when (> x 7) x))
10:59	pandeiro	duck1123: right, in my case i need to retrieve the val anyway, so why not return the val
10:59	pandeiro	seems it would make no sense to convert val to boolean and then retrieve the val again
10:59	pandeiro	but maybe the wiser people know a reason that would make sense
11:04	alexyakushev	duck1123: Why would returning a value make the predicate slower? Is there any difference in performance between returning a boolean or a reference to an object?
11:06	pandeiro	alexyakushev: think he means if you add the conditional (when...)
11:06	Chousuke	generally you should only return true or false explicitly in two cases: you're expecting the function to be used in Java code or when you want to return true for nil/false input
11:21	Bronsa	is there a function that trasforms [1 2 3 4] to ((1 3) (2 4))?
11:21	gfredericks	what's the rule there?
11:22	gfredericks	what does it do with [1 2 3]? or [1 2 3 4 5 6]?
11:22	gfredericks	do you only care about 4-tuples?
11:22	Bronsa	one element in the first list, one in the other
11:22	Bronsa	i can do that with ((juxt keys vals) (apply assoc {} coll))
11:22	Bronsa	buyt it feels too much like cheating
11:23	gfredericks	,(partition 1 2 [1 2 3 4])
11:23	clojurebot	((1) (3))
11:23	gfredericks	hm
11:23	Bronsa	yeah i tried partition
11:24	gfredericks	there are proably 40 cludgy ways to do it
11:31	gfredericks	,(let [pairs (partition 2 (range 6))] [(map first pairs) (map second pairs)])
11:31	clojurebot	[(0 2 4) (1 3 5)]
11:31	gfredericks	that's the cleanest I can think of
11:31	Bronsa	oh, cool thanks!
11:33	mdeboard	amalloy_: lol. I'd like to hear more about the dumb things I did wrong.
11:33	mdeboard	amalloy_: (seriously)
11:43	mdeboard	amalloy_: https://github.com/mattdeboard/clj-itext/blob/master/src/clj-itext/core.clj is the full file. PdfReader is a class from iText, a PDF-processing library. It has a very painful API. So when you say I've reinvented being crazy wrt my usage of metadata, I'm assuming what you really mean is "that's dumb." Why? I was basically just using it to store metadata about the PDF on the class instance.
11:46	pyrtsa	gfredericks, Bronsa: Here's a little simpler still:
11:46	pyrtsa	,(apply map list (partition 2 (range 6)))
11:46	clojurebot	((0 2 4) (1 3 5))
11:47	Bronsa	eg! thanks
11:59	gfredericks	pyrtsa: oh of course
12:00	pyrtsa	gfredericks: To be honest, it wasn't that obvious to me at first either.
12:01	Bronsa	this is funny http://i.imgur.com/GzpUF.png
12:04	gfredericks	pyrtsa: the (map list ...) things does matrix transpose; I just didn't realize that's what he was asking for
12:05	Bronsa	gfredericks: yeah, sorry if I didn't explain myself properly
12:06	Bronsa	thanks both anyway :)
12:12	gfredericks	Bronsa: oh no it was me
12:20	sproust	ist
12:20	sproust	technomancy: I just saw nrepl.el
12:20	sproust	technomancy: got a few questions about it.
12:21	sproust	Why two modes? I saw there's a major and a minor mode. If it's meant to be used with clojure-mode, why not just have a minor mode?
12:34	duck1123	"code generated by ClojureScript macros must target the capabilities in ClojureScript" -- does that mean I can't make a macro that calls console.log ?
12:34	duck1123	I'm getting odd errors when I try
13:01	sproust	technomancy: Ah. never mind. Figured it out, forgot the repl installs its own mode.
13:45	Frozenlo`	I get this error when I try to evaluate a function: clojure.lang.Symbol cannot be cast to clojure.lang.IPersistentCollection.
13:45	Frozenlo`	The function evaluates fine by itself, but when I add a given macro in it, it chokes. Any idea why?
13:48	pandeiro	does himera only work with lein <2? anyone know?
13:49	pandeiro	i get an error: Problem requiring leiningen.js hook
13:49	mdeboard	Frozenlock: Not without seeing the code
13:51	Frozenlock	mdeboard: https://gist.github.com/3258950 the macro is used near the end of the function.
13:51	mdeboard	Frozenlock: You're missing something
13:52	mdeboard	oh, nm, there the signature defintiion
13:52	Frozenlock	You litteraly, or in my understanding?
13:52	mdeboard	didn't see it
13:52	mdeboard	why do you have a vector in your args like that
13:53	Frozenlock	that? [[fetch-fn coll & {:as args}]]
13:53	mdeboard	yeah
13:53	mdeboard	is thata macro thing I'm not familiar with?
13:54	Frozenlock	(with-random (fetch ....)) would be single argument. With the added vector I use destructuring to directly get the components.
13:55	Frozenlock	Could it be that the arguments aren't evaluated, thus I don't have a map as a I was expecting, but simply a symbol?
13:56	treehug	are there refactoring tools for clojure like for example: extract sexp to local variable, rename symbol in sexp, etc?
13:56	mdeboard	Dunno, seems weird. On line 31, the (fetch (...)) expression is going to be evaluated before it's passed to (with-random)
13:56	Frozenlock	So the query-map in `:where query-map' will not be a simple symbol if I understand correctly.
13:57	mdeboard	I dunno, that is some weird-to-me syntax (but I'm not an expert by any stretch)
13:57	Frozenlock	ok, thanks anyway.
14:00	mdeboard	What is that function signature supposed to do? Destructure? I've literally never seen a vector used as a symbol
14:02	mdeboard	supposed to represent*
14:02	Frozenlock	If you are talking about the macro, yes it's for destructuring.
14:02	mdeboard	That shouldn't be in the function signature though
14:02	Frozenlock	Signature?
14:03	mdeboard	in ``(defn foo [a b] (+ a b))`` ``[a b]`` is the signature
14:04	mdeboard	destructuring should be in binding statements like let/for/etc.
14:04	metellus	mdeboard: you can destructure in a function signature
14:04	mdeboard	I see
14:06	mdeboard	That seems weird, since if you're just destructuring in the signature why not just pass the function the destructured args in the first place?
14:06	metellus	Frozenlock: based off of this http://stackoverflow.com/questions/11170424/maintaining-agent-state-while-returning-in-clojure and completely making things up, I'd say that you need to put "fetch-fn coll & {:as args}" into parentheses
14:07	gfredericks	mdeboard: in a lot of cases that could mean spreading implementation information all around your code rather than keeping it in one place
14:07	metellus	mdeboard: so instead of (some-fn some-vec) you'd have to do soething like (let [;destructuring goes here] (some-fn args))?
14:10	mdeboard	or just restructure in a different let statement, it's just a convention that I've never seen before (except obv like `(defn foo [x & [y z]] (stuff x y z))`
14:11	Frozenlock	I think I should be using a function instead of a macro in this case. Let me try that...
14:16	muhoo	i've seen a lot of people writing functions with quoting and unquoting ` ~ ' etc, i call the "funcros"
14:17	gfredericks	muhoo: misquote is good for ` without symbol expansion
14:17	gfredericks	i.e., for just the unquoting mechanisms
14:21	muhoo	yeah, the first time i saw gensyms and syntax-quotes in a non-macro, i was confused. then i figured out how useful it could be.
14:22	gfredericks	,`foo#
14:22	clojurebot	foo__27__auto__
14:22	Frozenlock	Meh, it works as a simple function and without the quoting unquoting stuff. Perhaps I was trying to be to fancy.
14:51	mdeboard	funcros
14:51	mdeboard	I liek that.
15:14	sjl	I'm trying to eliminate reflection and can't seem to figure out the magic type hinting incantations... anyone feel like taking a look? https://gist.github.com/3259412
15:20	sjl	oh sweet, I think I found it
15:26	antares_	sjl: you more likely want to use hints before locals: ^String s, not s ^String (…). Also, the last parameter needs to be passed as a java array, so see clojure.core/into-array
15:27	sjl	antares_: actually this does the trick: https://gist.github.com/3259412
15:27	sjl	antares_: there's an alternate version of that method that takes a set instead of that weird java varargs
15:27	sjl	antares_: I just had to inform clojure that (set foo) does indeed produce a persistenthashset
15:28	antares_	sjl: it is still less common to hint expressions if you bind them to locals but ok. And interop with variadic methods is a common source of confusion so I decided to mention it.
15:29	antares_	sjl: to hint on core Clojure types, it is probably a better idea to use interfaces (IPersistent*)
15:29	antares_	also, you probably can just hint it has java.util.Set?
15:29	sjl	maybe
15:29	antares_	the Java method is likely to be expecting j.u.Set, not a specific Clojure interface
15:30	antares_	Clojure sets implement the read-only part of j.u.Set
15:30	sjl	ah
15:33	pandeiro	anyone noticed a bug with goog.json.parse() ? JSON.parse() is parsing my string just fine, goog.json.parse() isn't
16:44	wtetzner	pandeiro: what string are you trying to parse?
16:51	pandeiro	wtetzner: sorry i figured it out - goog.json.parse uses eval, which is prohibited in chrome extensions
16:52	antares_	pandeiro: are you writing a chrome ext in cljs?
16:52	pandeiro	kinda silly that goog.json.parse doesn't first check for a native method imo, but whatever
16:52	pandeiro	antares_: i am
16:52	pandeiro	and i'm loving it
16:53	emezeske	pandeiro: That is really cool!
16:55	pandeiro	emezeske: yeah my first try was a couple of months ago, i wanted to convert himera to a chrome extension that would allow using CLJS on any random webpage
16:55	pandeiro	but i ran into the no eval() problem
16:55	pandeiro	there is a workaround tho, eventually i will get on that
16:56	emezeske	pandeiro: Oh, neat, the extension would like see a special script tag and send it off to himera seamlessly?
16:56	pandeiro	emezeske: ah no, just to be able to screw around in cljs on any random page
16:56	emezeske	pandeiro: I see
16:57	emezeske	pandeiro: Cool stuff
16:57	pandeiro	eventually have a store of convenience functions, like get-all-links
16:57	pandeiro	yeah, eventually i'll get there
16:57	pandeiro	with cljsbuild it has been very easy throwing together an extension
16:57	emezeske	nice!
16:57	pandeiro	since you can output to multiple files easily
17:05	pandeiro	say i have a flattened seq like (:head :sub :sub :sub :head :sub :sub :head :sub :sub :sub) and i want to restore the hierarchy like ([:head (:sub :sub :sub)] ...)
17:09	pandeiro	i got to using partition-by to get ((:head) (:sub :sub :sub) (:head) (:sub :sub) ...) ... trying to figure out the next step
17:11	gfredericks	pandeiro: (->> % (partition 2) (map (fn [[[h] subs]] [h subs])))
17:12	pandeiro	gfredericks: my mind reached its recursion limit with that destructuring
17:12	pandeiro	but thank you, am trying to parse
17:12	gfredericks	it's just pulling the head and the subs out of your ((:head) (:sub :sub :sub))
17:26	Frozenlock	Is there a way to use drag/drop in html5 without javascript?
17:30	Raynes	Rewriting all the temp file/dir stuff and making other things less weird.
17:30	Raynes	Going to commit-bomb the repo soon.
17:33	antares_	Raynes: (with the towlie voice) don't forget to use travis-ci
17:33	Raynes	antares_: I'm not already doing that?
17:33	Raynes	Hrm.
17:33	Raynes	Guess I just haven't worked on fs in a while.
17:33	Raynes	I'll get that set up before releasing.
17:35	Raynes	Also, if anybody has ever found something weird or un-nice in fs, nows your chance to get it fixed while I'm on a roll.
17:35	Raynes	I didn't write the vast majority of this code and I haven't used fs a whole lot, so I'm not the one who would know about issues.
17:36	Frozenlock	Well, a more detailed readme could be nice. (to know what that's all about)
17:37	Raynes	It's all about the fs, man.
17:37	Frozenlock	cricket
17:40	technomancy	Imma let you finish but reiserfs was the best fs of all time
17:40	Raynes	technomancy: You're so hip and with it.
17:40	danlarkin	murders your wife ✓
17:45	amalloy	mdeboard: you aren't actually storing the metadata, though. like, your implementation of withMeta returns a map, instead of a new object with new metadata
17:46	amalloy	which is, in turn, what makes with-proxy-meta's implementation so bizarre. with-proxy-meta should be able to just be a simple call to ##(doc vary-meta)
17:46	lazybot	⇒ "([obj f & args]); Returns an object of the same type and value as obj, with (apply f (meta obj) args) as its metadata."
17:47	technomancy	so what if namespaces were persistent?
17:47	technomancy	what if new definitions were append-only and old function definitions stayed around until there were no other references to them?
17:48	technomancy	if you used nix-style hashing and dependency closures, you could keep multiple versions of a library in memory in the same classloader
17:50	technomancy	you could theoretically have every version of every clojure function loaded at once without conflict
17:51	gfredericks	technomancy: so you just solved dependency management then?
17:52	technomancy	no, I just told you how to solve it. go implement it.
17:52	Spaceghostc2c	Hagelberg!
17:53	technomancy	me?
17:54	gfredericks	~hagelberg
17:54	clojurebot	Gabh mo leithsc?al?
17:59	jayunit100__	trying to convert csv to json
18:00	jayunit100__	any hints on the standard lib to do this csv i/o (clojure)
18:00	jayunit100__	trying [clojure-csv/clojure-csv "2.0.0-alpha1"]
18:19	Frozenlock	What's the way to add a favicon in noir?
18:23	Raynes	Frozenlock: https://github.com/Raynes/refheap/commit/3fa0100722faad54418a1e712dcf0176463b789d
18:24	jayunit100__	(:import [java.io StringReader]) <-- this seems to fail
18:24	Frozenlock	Raynes: Thanks!
18:27	jayunit100__	ah dsantiago !
18:27	jayunit100__	I'm using your csv parser now :)
18:27	jayunit100__	dsantiago: ^^ … thanks :)
18:28	dsantiago	Oh, cool.
18:28	dsantiago	I've been speeding it up lately.
18:28	jayunit100__	cool!
18:28	jayunit100__	Caused by: java.lang.IllegalArgumentException: Unable to resolve classname: long
18:28	jayunit100__	^^ anyone ever see this error before?
18:30	jayunit100__	ah i think its clojure class path related
18:30	jayunit100__	or maybe its leon related.
18:31	dsantiago	Did you hint something to be a long or try to create one like (long. …) or anything like that?
18:35	jayunit100__	looks like you have to reload lein reps or something maybe .
18:35	jayunit100__	no its not in my source, it seems to be in a jar.
19:23	Frozenlock	Is there a forum library for clojure?
19:37	mdeboard	amalloy: I see, noted
19:38	cmajor7	forgot where I read how to force (re)compilation on save.. e.g. I have it working nicely with clojurescript via "lein-cljsbuild".. I am sure there is something similar (and probably simple) for clojure itself
19:39	cmajor7	is it just another lein plugin?
19:40	xeqi	cmajor7: web service?
19:40	xeqi	ring.middleware.reload I think
19:41	cmajor7	xeqi: thx. no, simpler :) just clojure code
19:41	weavejester	cmajor7: (:require blah.core :reload)
19:42	weavejester	cmajor7: Er, I mean: (require 'blah.core :reload)
19:42	weavejester	Too used to the ns macro
19:42	cmajor7	once I save any clojurescript file, it gets recompiled right away, and I can see in a console whether there are any errors. just wanted to do the same thing with clojure itself
19:43	cmajor7	weavejester: so I would need to append :reload to every namespace… I have ~ 15 files, is that the only way?
19:43	weavejester	cmajor7: There's also :reload-all, which reloads a namespace and all its dependencies.
19:43	amalloy	i don't think it's ever right to put :reload into your namespace definition
19:44	cmajor7	I think there is something similar in emacs land (swank?), but I am using vi. not sure if that matters
19:44	amalloy	that's only intended for repl usage
19:44	weavejester	amalloy: Right, but I'm assuming cmajor7 is reloading via the REPL...
19:44	weavejester	cmajor7: Is that right?
19:45	amalloy	(as an aside, you forgot the []s in (require '[blah.core :reload]))
19:45	amalloy	or i dunno, maybe it works outside
19:45	cmajor7	weavejester: I just want to start "something", that would be running, and every time I save my code, I it gets recompiled, and that "something" reports exceptions/errors/etc..
19:46	emezeske	cmajor7: I think most people use vimclojure or swank or something similar for that
19:47	emezeske	cmajor7: I have heard of people adding hooks to their editors that automatically reload the current file on save
19:47	weavejester	cmajor7: Usually I just use SLIME for that. I believe VimClojure might have something similar. And some of the various IDEs might have that, too.
19:47	emezeske	s/swank/slime
19:47	cmajor7	emezeske: I use vimclojure, but as far as I understand you need to always force the compilation e.g. "\ef"
19:47	cmajor7	which pops up an internal vim buffer that you have to switch to and close
19:48	cmajor7	or worse scroll up to actually see the exception
19:48	emezeske	You don't have to switch to it, you can do \p to close it
19:48	cmajor7	feels like 4 extra steps for every save..
19:48	emezeske	And you can set options for where it appears, and how big
19:48	emezeske	You can just leave it open...
19:48	cmajor7	right, but if there is an exception, you have to switch to it to scroll up
19:49	weavejester	cmajor7: Isn't that an issue with screen size more than anything? I mean, if the stacktrace scrolls off screen, then you'd have the same problem with whatever, right?
19:49	mdeboard	amalloy: With the definition of withMeta, I spent a few hours last night trying to figure out how to extend an Object instance with the IObj interface. I basically just hacked at it until it works. I couldn't find an example implementation of withMeta (except for one really crummy blog post from 2009)
19:49	cmajor7	I just really like what "lein-cljsbuild" does, and I find it hard to believe there is nothing similar for clojure itself?
19:50	amalloy	mdeboard: just look at the examples in clojure.lang
19:50	amalloy	they're in java, but it's pretty easy
19:50	mdeboard	amalloy: I tried to find it in the source last night but I think I was exhausted
19:51	mdeboard	I found the IObj.java and IMeta.java classes, but there's no actual code there, just interface defs
19:51	weavejester	cmajor7: I haven't heard of anything. I find it more useful to have errors integrated with my editor. However, it would be pretty trivial to create something like it. Just combine clj-stacktrace, ns-tracker, and :reload-all in a loop.
19:51	weavejester	I imagine it would be 8 lines of code or something.
19:52	mdeboard	er, I should say, no function definitions, not no code :P
19:52	amalloy	look at, eg, PersistentHashMap
19:55	muhoo	cmajor7: i think noir does it on page reload
19:55	cmajor7	weavejester: I see. still find it odd. do you actually go an extra step every time to see if your code is solid? e.g. 1. save it 2. force compilation 3. go scroll the exception ?
19:56	mdeboard	amalloy: I see... so, do I need to specify a constructor for this PdfReader class that has a signature that includes metadata? Based on PersistentHashMap, I'm not sure how to do something similar for this class instance. PersistentHashMap implements the IObj interface out of the box; PdfReader not.
19:56	weavejester	cmajor7: No, I just use SLIME.
19:57	amalloy	just...implement withMeta to call proxy-meta or whatever it is
19:57	cmajor7	muhoo: noir does, but if you work with 3 files simultaneously, going from one vim buffer to another and back, saving each, noir does not help you here (nor it should)
19:57	cmajor7	weavejester: I see. how does it work in slime?
19:57	cmajor7	it auto recompiles on save?
19:57	amalloy	you really don't want to recompile on save
19:58	weavejester	cmajor7: No, but it saves if you trigger a compile without saving, IIRC
19:58	cmajor7	amalloy: why not?
19:58	muhoo	cmajor7: i dunno then. i was poking in the cljsbuild source, and stumbled across the function that checks the filesystem for changed files, but didn't read it in depth. you could probably adapt that to a lein plugin that does that for clj instead of cljs
19:58	weavejester	cmajor7: And the error is reported through SLIME, so the top part of the stack trace is shown
19:59	weavejester	muhoo: There's a library called ns-tracker that does that for clojure
19:59	cmajor7	weavejester: pretty similar to vimclojure.. although the bottom of the exception is shown.. )
19:59	amalloy	for example, you don't want to recompile a protocol implicitly, because then implementations of it won't match up anymore
20:00	weavejester	cmajor7: Why not add a key binding that saves, compiles, then goes to the top of the exception?
20:02	cmajor7	amalloy: does sound like a special case, and implementations can be also recompiled after the protocol, can they?. I am not saying it should be enabled by default, but there should be something that does it as an option.
20:05	cmajor7	weavejester: might work, but still a bit rough. let's say you are working through several files related to one another. ideally there should be a single console that shows you errors/[OK]s/exceptions every time you save and go to another file. so your mental flow is not interrupted.. (may be it's just me though)
20:09	muhoo	it is funny to me how personal and unique everyone's workflow can be. mine is quite idiosyncratic.
20:10	amalloy	cmajor7: just write a little shell script that compiles everything, eg: echo "(require 'my-app.core)" \| lein repl, and then open another console that runs: watch my-script.sh
20:11	amalloy	there's no need for it to happen when you save, or be incremental and mess with your open session
20:12	cmajor7	amalloy, weavejester: thx, I'll experiment
20:26	gfredericks	does the new finite-domain stuff in core.logic not play well with negative numbers?
20:29	gfredericks	I get no results with (interval -100 100) (even though I should), but changing it to (interval 1 100) gives results.
20:43	mdeboard	Man the people who wrote iText must hate programmers
20:44	mdeboard	or love carpal tunnel syndrome or I dunno
20:55	amalloy	i can sympathize with hating programmers
20:58	mdeboard	amalloy: That is obvious, but that's why we like you. To be fair to the itext people I'm sure they're in backward compatibility hell. I know they are actually because they put all their backward compatibility burden on me
21:09	mdeboard	Is there a way to invoke (proxy) in such a way that the class being extended doesn't get constructed first? I've been reading the source for the macro and am assuming not.
21:10	mdeboard	I think that's the sort of thing Python's ``object.__new__`` method is there for; curious if there's an analog in Clojure specifically for Java interop.
21:14	amalloy	sorry mdeboard, that is not possible on the jvm
21:42	mdeboard	amalloy: Cleaned that up then https://github.com/mattdeboard/clj-itext/blob/master/src/clj-itext/core.clj#L43
21:43	mdeboard	removed `with-proxy-meta' since it was redundant
21:43	amalloy	don't call `merge`. withMeta is "here is your new metadata"
21:45	mdeboard	which merge is redundant? in the withMeta definition?
21:45	amalloy	not redundant, incorrect
21:46	amalloy	(and yes, that one)
21:46	amalloy	(meta (with-meta x y)) should return y in all cases
21:46	mdeboard	Oh, I see what you're saying then. with-meta completely replaces the metadata.
21:46	mdeboard	I misunderstood how that worked.
21:48	mdeboard	##(doc vary-meta0
21:48	mdeboard	##(doc vary-meta)
21:48	lazybot	⇒ "([obj f & args]); Returns an object of the same type and value as obj, with (apply f (meta obj) args) as its metadata."
21:48	mdeboard	I see.
21:52	amalloy	what, does chas say something misleading about metadata?
21:52	mdeboard	No, I just don't believe in taking personal responsibility
21:54	mdeboard	But seriously, having no Java background whatsoever the proxy/gen-class bit specifically could use somewhat better documentation. Maybe it's more transparent if you've got a background in Java
22:06	mdeboard	amalloy: Done, thanks for the tough love
22:06	mdeboard	I work better when I think someone thinks I'm an idiot
22:08	amalloy	haha
22:08	amalloy	you should pair with hiredman
22:10	danlarkin	bahahahah
22:10	mdeboard	Why, does he think I'm an idiot? :P
22:10	mdeboard	or does he just think everyone is
22:11	muhoo	,ns
22:11	clojurebot	#<Namespace sandbox>
22:11	muhoo	,(= :sandbox/foo ::foo)
22:11	clojurebot	true
22:12	cmajor7	once friend authenticates a user, it puts "{ :username.. :password… :roles.." under the identity into a session. Is there a way to make friend to keep additional user details there? (e.g. user-id)
22:13	muhoo	well, you can using ring
22:13	muhoo	just add whatever you want to the :session
22:14	xeqi	cmajor7: try returning more data from you're credentials-fn
22:14	cmajor7	yea, I just did, it still hangs on to those 3
22:15	muhoo	cmajor7: are you writing a custom workflow?
22:15	cmajor7	muhoo: yes, but it is not going to be a part of friends identity + needs to be handled separately => not nice
22:15	muhoo	i wrote one for google step2 auth, but it's been months now and my memory fails me
22:16	cmajor7	muhoo: no this particular one is a built in "interactive-form"
22:16	muhoo	oh, so you're out in ring?
22:17	muhoo	not inside a (defn workflow ... ) ?
22:17	cmajor7	muhoo: I am home at the moment
22:17	muhoo	hehe
22:17	muhoo	i mean not you specifically, but your code :-)
22:18	cmajor7	there is a "credentials-fn" that returns the auth
22:18	cmajor7	which is the only "data hook" into friend that is used
22:18	muhoo	:credential-fn i expect
22:18	muhoo	no "s"
22:18	cmajor7	the app is of course ring based. noir to be exact
22:19	cmajor7	right. "bcrypt-credential-fn" if you want to be really accurate
22:19	muhoo	cool, so my guess is you have something like this in your server.clj: https://www.refheap.com/paste/4047
22:20	cmajor7	yep. very similar
22:20	cmajor7	no "step2" though
22:20	muhoo	well, of course
22:20	muhoo	that was my test code
22:21	muhoo	alright, so you're using creds/bcrypt-credential-function. what does it return?
22:21	cmajor7	so once the user is authed, only username, password and roles make it to the identity
22:21	muhoo	somewhere, something returns a ring response, which has (or can have) a :session key in it
22:22	cmajor7	muhoo: it returns a map of those 3. I tried to add other keys there, but they get ignored, since only those 3 seem to be read by friend
22:22	muhoo	by interactive-form
22:23	clj_newb_29840	is there any standard toolkit for keeping _data structures_ updated on client/server over clojurescript/clojure?
22:23	clj_newb_29840	i.e. I'd like ot find the right abstractions so I have some data structure so that its state is automatically synched over both the server and the client
22:24	xeqi	cmajor7: strange, returning extra-keys there works for me
22:25	muhoo	cmajor7: ok i see this (assoc-in [:session ::identity] auth))
22:25	cmajor7	muhoo: right, http://bit.ly/PUxKWX
22:25	cmajor7	xeqi: interesting.. which key did you try, if you don't mind
22:26	muhoo	so whatever is returned in auth, from the who-knows-where-that-comes-from, should end up in your session
22:26	cmajor7	I tried, id, user-id, but no go..
22:26	xeqi	:extra
22:27	xeqi	but the only one creds/bcrypt-crednental-fn removes is :password
22:27	xeqi	blah, I can't spell today
22:27	muhoo	i remember i spent days tracing through the (authenticate* ..) function to figure out how all this works, but i've long since forgotten
22:28	muhoo	with like printlns everywhere
22:36	cmajor7	xeqi: yep, works now. had to restart the server
22:36	cmajor7	I wonder why… since I did clear the session (it does it on logout)
22:39	xeqi	noir's reload doesn't work with middleware
22:44	Frozenlo`	Anyone wants to critic my website? (general layout, colors, etc...) Made with love with Noir :) https://bacnethelp.com
22:47	Frozenlock	I'm pretty sure I have tunnel vision right now, so please be direct.
22:48	emezeske	Frozenlock: Whoa, I worked on a BACnet stack once
22:48	Frozenlock	emezeske: Yay! BACnet friend :)
22:48	emezeske	Frozenlock: I wrote the MS/TP layer :)
22:48	Frozenlock	The C stack?
22:48	emezeske	Yeah, it was all C. Well, actually, C++
22:48	xeqi	Frozenlock: I can't read the example at all
22:48	xeqi	well, barely
22:48	Frozenlock	Oh I only do BACnet/IP with this.
22:49	Frozenlock	xeqi: Colors?
22:49	emezeske	Yeah, MS/TP is a bitch to set up, and tends to require custom code most of the time :/
22:49	muhoo	cmajor7: right, i had to do stuff like this https://www.refheap.com/paste/4048 and this (def rel (reloader #'-main)) and this https://www.refheap.com/paste/4049
22:49	cmajor7	xeqi: ah.. makes sense, good to know (about noir reload)
22:49	emezeske	Frozenlock: BACnet/IP is so much better
22:49	Frozenlock	emezeske: And it's slooooow :)
22:49	emezeske	Frozenlock: omg yeah
22:50	mdeboard	Frozenlock: Where are you hosting your images?
22:50	mdeboard	oh, I see you just acknowleged
22:50	mdeboard	Frozenlock: Only thing I'd say is have your links open up in new windows
22:50	mdeboard	target="_blank" etc
22:51	Frozenlock	mdeboard: All the links?
22:51	cmajor7	muhoo: hmm.. I wonder whether I should just jump a level down to compojure.. so far noir introduces more problems than it solves..
22:51	Frozenlock	Seems it would be intrusive.
22:51	xeqi	Frozenlock: http://imgur.com/s4qnX is what I get on ff14.0.1
22:51	mdeboard	Frozenlock: well just external, like the one to github imo
22:51	muhoo	cmajor7: you wouldn't be the first to do that. i think that's why they broke out a lot of noir-ish stuff into lib-noir
22:51	Frozenlock	Hmm that would be wise...
22:52	cmajor7	muhoo: also, how do you usually debug through a 3rd party libs? (you said to did do it with friend's "authenticate*")
22:52	xeqi	cmajor7: I use compojure over noir
22:52	muhoo	cmajor7: i'm old-skool. lots of printlns :-)
22:53	muhoo	and the repl helps a lot too, though not so much with web authentication stuff that requires a browser
22:53	cmajor7	muhoo: so you get the source, and depend on the source.. and then mod it in the friend's branch itself?
22:53	xeqi	Frozenlock: oh, if I hover over it then it expands and becomes brighter
22:53	Frozenlock	xeqi: Is that too discrete? If you hover it should change transparency...
22:53	emezeske	cmajor7: If you are doing anything complex with routing, noir tends to just get in the way
22:53	cmajor7	xeqi: you mean you use noir, but drop back to compojure for routes?
22:53	muhoo	oh, that? yes, i git cloned'ed friend, then ln -s'ed it into the "checkouts" directory in the lein project
22:54	xeqi	cmajor7: sorry, I mean use compojure, don't use noir
22:54	cmajor7	emezeske: yea I noticed that doing xhr.. :)
22:54	emezeske	cmajor7: ;)
22:54	cmajor7	xeqi: I see.. do you roll out your own "defremotes"?
22:55	muhoo	isn't defremote from fetch?
22:55	cmajor7	muhoo: yea, but fetch is noir..ish
22:55	Frozenlock	And here is a project I'm logging https://bacnethelp.com/project/4ffac84b44ae35711d15d214
22:56	Frozenlock	So my most urgent change should be to open external links in another window.
22:57	mdeboard	Frozenlock: Also see about solving package dependencies
22:57	mdeboard	not website-related but you'd be a hero
22:57	mdeboard	I could also use a drink
22:57	xeqi	cmajor7: I haven't used clojurescript much yet, but that would be the way I lean
22:57	Frozenlock	package dependencies? For the network scanner?
22:58	xeqi	though I'm interested in what shoreleave does for remotes
22:58	xeqi	just haven't explored it yet
22:58	mdeboard	Frozenlock: Oh, no, I Meant for software development in general
22:58	Frozenlock	I _really_ appreciate your feedbacks btw!
22:59	mdeboard	(I'm deliberately being obtuse)
22:59	Frozenlock	mdeboard: Could you give me an example?
22:59	xeqi	ah, looks like it does the same thing as fetch
22:59	Frozenlock	Dependencies are in the project.clj file... am I missing something?
23:00	mdeboard	I was just making a joke that was in hindsight really stupid
23:00	Frozenlock	It's hard to transmit sarcasm with text :P
23:00	mdeboard	yeah, you'd think I'd have learned in 20 years
23:02	cmajor7	xeqi: yep http://bit.ly/OBWSWk
23:03	muhoo	yeah, i think rhickey and stuart holloway both did talks about "easy" vs "simple"
23:03	muhoo	stuff like noir and fetch is great if you're coming from rails and are used to the "easy" approach. but aren't necessarily "simple" once you dive into them.
23:05	mdeboard	Frozenlock: You should move that "How to scan your network" numbered list up "above the fold" imo, and put your "Download" button right there in the "1!" <p>
23:06	Frozenlock	Ah! Yes!
23:07	xeqi	Frozenlock, mdeboard: I agree. and if you can get it so that is the first thing the eye jumps to even better
23:07	xeqi	currently my eye jumps to the "Scan and see ..." blue banner
23:08	xeqi	muhoo: yeah, cemerick was horrified at the hoops I had to jump through to get a working noir/fetch + friend example
23:13	muhoo	xeqi: is that posted somewhere? i'd be curious to see it
23:14	xeqi	muhoo: https://github.com/xeqi/friend-fetch-example
23:14	xeqi	interesting part is https://github.com/xeqi/friend-fetch-example/blob/master/src/friendly/server.clj
23:17	muhoo	hmm, there's a lot going on there
23:19	muhoo	it looks a lot less complex than what i had to go through to get google step2 workflow working, but a lot more complex than perhaps it could be.
23:20	xeqi	muhoo: yeah, it could be cleaned up
23:20	xeqi	step2 definitly looks more complicated
23:20	xeqi	is it a multistep workflow?
23:31	m0smith	I am trying to wrap my brain around event processing in a purely functional environment
23:32	m0smith	How can the state of the world be passed around?
23:33	mdeboard	(##doc ref)
23:34	Raynes	That was creatively failed.
23:34	mdeboard	m0smith: Clojure has tools that allow you to introduce state to your application if necessary.
23:34	mdeboard	##(doc ref)
23:34	lazybot	⇒ "([x] [x & options]); Creates and returns a Ref with an initial value of x and zero or more options (in any order): :meta metadata-map :validator validate-fn :min-history (default 0) :max-history (default 10) If metadata-map is supplied, it will be come the meta... https://www.refheap.com/paste/4050
23:34	m0smith	mdeboard: I am trying to avoid that is possible
23:34	mdeboard	m0smith: Are you talking about cljs or clj?
23:35	m0smith	both actually
23:35	m0smith	The problem arises from cljs not having blocking deref
23:36	m0smith	so how to get the same code base to run in both environments. javascript is all about callbacks but that assumes a shared state, I think.
23:36	emezeske	m0smith: For state in cljs, there's a good chance you want to use an atom
23:37	muhoo	you could pass the state in the callback?
23:38	muhoo	oic, it'll depend on the state which may have mutated by the time the callback gets called. hmm.
23:39	m0smith	muhoo: I am writing a multi-player game so the state is the current state of the game which I want to protect from cheating code
23:39	mdeboard	Never done anything with asynchrony with Clj* but I was under the impression from what I do know that you could use watches to do event handling
23:39	mdeboard	##(add-watch)
23:39	lazybot	clojure.lang.ArityException: Wrong number of args (0) passed to: core$add-watch
23:39	mdeboard	##(doc add-watch)
23:39	lazybot	⇒ "([reference key fn]); Alpha - subject to change. Adds a watch function to an agent/atom/var/ref reference. The watch fn must be a fn of 4 args: a key, the reference, its old-state, its new-state. Whenever the reference's state might have been changed, any regis... https://www.refheap.com/paste/4051
23:39	mdeboard	fail tonight
23:42	muhoo	m0smith: sounds like fun. it sounds like you'll want a mirror of the state in the server and on all the clients.
23:43	muhoo	the only time i've done this (js, not cljs), i had the server broadcasting all the updates of each player to each client.
23:43	m0smith	muhoo: Exactly. The game engine would have the real state and when it is a players turn, the client is sent the current state
23:44	m0smith	I also thought of supporting events from the clients to get the current state or send a message, etc.
23:44	muhoo	the server was basically this, but it didn't keep much state: https://github.com/kenrestivo/simple-clojure-websocket-chat
23:44	m0smith	I am just having a brain cramp meshing the game loop with asynchronous calls without something like an agent
23:44	m0smith	that can block
23:45	muhoo	started as a chat thing, then ended up as a gameserver of sorts, more or less unwillingly
23:46	m0smith	or do I just trash the game loop and handle everything through asychronous events?
23:47	muhoo	it's worth a try. also, there's a neat aleph framework for doing async stuff too
23:47	m0smith	which is then how to maintain state without a stuffing it in a global ref ...
23:47	muhoo	well, state is state. you have to store it somewhere
23:48	m0smith	with a game loop/lazy-seq the state is simply passed around to the functions
23:50	muhoo	do any of those functions do i/o?
23:51	m0smith	I am separating all the user stuff into different threads so no
23:51	muhoo	oh. hmm.
23:52	muhoo	concurrency with refs. i haven't done much with it, but i'm told that clojure makes it more manageable.
23:53	m0smith	The more I think and talk about it the more a shared state atom or agent supporting an event system may solve the problems I am facing
23:54	muhoo	sounds reasonable to me. might be a fun way to play around with clojure's concurrency features.
23:54	m0smith	And it should mesh better with most UIs as they are almost all event based at some level
23:56	m0smith	https://github.com/m0smith/crossfire is the code I am talking about. It is a Battleship-ish game. Now all it does is allows 3 computer players to battle.
23:56	muhoo	enjoy :-)
23:57	m0smith	thx. This has really helped me make decide the direction to go