#clojure – 2015-08-05

2015-08-05

00:01	lsdfajklsd	test
00:01	lsdfajklsd	rhaywood: yt?
00:01	justin_smith	ran 0 tests with 0 assertions, 0 fails, 0 errors
00:02	lsdfajklsd	rhaywood: (+ 1 1)
02:54	tdammers	hi... is this the right place for questions about clojurescript and figwheel?
02:56	Empperi	ok place, but #clojurescript is better
02:57	tdammers	aight
08:35	tgoossens	How do I typehint a 2d array?
08:37	justin_smith	, (into-array [(into-array [5])])
08:37	clojurebot	#object["[[Ljava.lang.Long;" 0x5d642c1f "[[Ljava.lang.Long;@5d642c1f"]
08:37	justin_smith	"[[Ljava.lang.Long;", though the java.lang.Long part is variable of course
08:38	justin_smith	"[[Lfoo'\;"
08:38	justin_smith	you can use the string where normally you would provide a class or keyword
08:42	tgoossens	justin_smith, again my hero of the day thanks!
08:53	snowell	(inc justin_smith)
08:53	lazybot	⇒ 284
08:54	hellofunk	what is easiest way to build binary number of arbitrary length with all bits turned on?
08:54	hellofunk	i.e. if i need length it builds 2r11111
08:54	hellofunk	length 5
08:56	chouser	,(Long/toBinaryString (- (bit-shift-left 1 5) 1))
08:57	clojurebot	"11111"
09:00	justin_smith	,(read-string (apply str "2r" (repeat 5 1))) ; less elegant
09:00	clojurebot	31
09:00	justin_smith	err
09:01	hellofunk	justin_smith: that is the correct result
09:01	hellofunk	just not printing as binary
09:01	hellofunk	which is fine
09:01	justin_smith	hellofunk: ahh, right
09:01	justin_smith	the bit-shift is probably two orders of magnitude faster :)
09:01	hellofunk	i suspect there is still a clever elegant option to using xor
09:02	hellofunk	I was thinking that 2r100000... xor with 0 will always be 2r011111....
09:02	hellofunk	wait
09:02	hellofunk	i mean bit-not, not xor
09:03	hellofunk	i should not think out loud
09:04	blackbird_	I have a line like (def tmc (client/text-connection (env :cache-endpoint))) When doing like `lein ring uberwar`, this fails because the env variable doesn't exist there and it attempts to create a connection to nil. Is there a general patterin for dealing with this type of thing?
09:05	hellofunk	i think i'll go with the chouser offering
09:05	chouser	Don't be too hasty. There may be benefits to the string-manipulation version that we haven't thought of yet. ;-)
09:06	justin_smith	blackbird_: the easy way is (def tmc (delay (clien/text-connection ...))) and then use @tmc where you would use tmc
09:06	justin_smith	blackbird_: the super proper way is to use stuartsierra/component for resources that are stateful
09:06	chouser	,(nth (iterate #(+ 1 (* 10 %)) 1) 5)
09:06	clojurebot	111111
09:07	chouser	oh, whoops, that's base 10
09:07	chouser	(Long/toBinaryString (nth (iterate #(+ 1 (* 2 %)) 1) 5))
09:07	chouser	,(Long/toBinaryString (nth (iterate #(+ 1 (* 2 %)) 1) 5))
09:07	clojurebot	"111111"
09:08	blackbird_	justin_smith: ahh cool. component way seems like overkill for one def, thanks for the tip
09:09	chouser	,(Long/toBinaryString (eval (read-string (nth (iterate #(str "(+ 1 (* 2 " % "))") 1) 5))))
09:09	clojurebot	"111111"
09:09	opqdonut	,(Long/toBinaryString (dec (bit-shift-left 1 6)))
09:09	clojurebot	"111111"
09:10	opqdonut	oh that was mentioned already ages ago
09:10	justin_smith	the bit-shift/dec combo is the best though
09:10	chouser	opqdonut: dec, of course!
09:10	chouser	nicely done
09:10	opqdonut	well it's actually the same number of characters as - 1 :)
09:11	chouser	hm, true. I prefer dec.
09:15	opqdonut	me too
09:16	opqdonut	I even use it on floats, but feel a bit dirty afterwards
09:17	justin_smith	,(dec (/ 131 7))
09:17	clojurebot	124/7
09:20	justin_smith	,(inc (/ 17 7)) ; how I rock it
09:20	clojurebot	24/7
09:34	tgoossens	How (using leiningen) can I compile java and clojure code AND have a java class use a class generated by clojure gen-class.
09:34	tgoossens	This is a problem since java is compiled first and then clojure
09:34	tgoossens	but in this particular case, clojure should be compiled before this one class
09:34	tgoossens	can I express such things in leiningen?
09:35	gfredericks	tgoossens: do you know for sure that you have to structure it that way? there are other ways of calling clojure code from java code
09:35	gfredericks	that don't require that order of compilation
09:35	hyPiRion	tgoossens: https://github.com/hyPiRion/multicompile-example
09:36	hyPiRion	essentially just do prep-task modifications
09:39	chouser	or move the gen-class code to another "project" and bring it in as a lein dep
09:42	TimMc	or use make
09:47	tgoossens	I added it as a Junit test (which in the end made more sense)
09:54	TimMc	fascinating
09:54	TimMc	Was it in fact a test?
10:01	wes_	hello. I've got a question if you've got time.
10:02	justin_smith	wes_: on IRC you don't need to ask, you can just ask
10:02	namra	wes_: just ask ^^
10:02	namra	^^
10:04	wes__	I want to apply a function to a seq with an init value and use the result of the function as the init value for the following iterations.
10:04	justin_smith	wes_: that's reduce
10:05	justin_smith	,(reduce + 2 [3 4 5])
10:05	clojurebot	14
10:05	gfredericks	,(reduce str 2 [3 4 5])
10:05	clojurebot	"2345"
10:05	gfredericks	,(reduce - 2 [3 4 5])
10:05	clojurebot	-10
10:05	gfredericks	,(reduce / 2 [3 4 5])
10:05	clojurebot	1/30
10:05	justin_smith	,(reduce conj [] [7 8 9])
10:05	clojurebot	[7 8 9]
10:05	gfredericks	,(reduce vector 2 [3 4 5])
10:05	clojurebot	[[[2 3] 4] 5]
10:06	justin_smith	,(reduce conj () [7 8 9])
10:06	clojurebot	(9 8 7)
10:06	gfredericks	,(reduce hash-set 2 [3 4 5])
10:06	clojurebot	#{#{4 #{3 2}} 5}
10:06	justin_smith	yeah, reduce is the greatest
10:06	gfredericks	(reduce reduce ? [? ? ?]) ;; ← make this work
10:06	wes__	(defn move-up [map vec-of-maps index] ...) -> new vec-of-maps with item moved to index
10:07	wes__	(reduce move-up vec-of-maps seq-of-maps) <---- this turns some of my maps into vectors of [k v]
10:07	gfredericks	,(reduce reduce conj [[1 2 3] [4 5 6] [7 8 9]])
10:07	clojurebot	#error {\n :cause "java.lang.Long cannot be cast to clojure.lang.IPersistentCollection"\n :via\n [{:type java.lang.ClassCastException\n :message "java.lang.Long cannot be cast to clojure.lang.IPersistentCollection"\n :at [clojure.core$conj__4104 invokeStatic "core.clj" 82]}]\n :trace\n [[clojure.core$conj__4104 invokeStatic "core.clj" 82]\n [clojure.core$conj__4104 invoke "core.clj" -1]\n [c...
10:07	gfredericks	dangit
10:08	gfredericks	,(reduce reduce + [[1 2 3] [4 5 6] [7 8 9]])
10:08	clojurebot	#error {\n :cause "java.lang.Long cannot be cast to clojure.lang.IFn"\n :via\n [{:type java.lang.ClassCastException\n :message "java.lang.Long cannot be cast to clojure.lang.IFn"\n :at [clojure.core$reduce invokeStatic "core.clj" 6516]}]\n :trace\n [[clojure.core$reduce invokeStatic "core.clj" 6516]\n [clojure.core$reduce invoke "core.clj" -1]\n [clojure.lang.PersistentVector reduce "Persist...
10:08	justin_smith	wes__: it would do that if seq-of-maps was actually a map
10:08	gfredericks	welp I give up
10:08	justin_smith	wes__: also, how are you giving a three-arg function to reduce?
10:09	wes__	woops. move-up takes two args [item coll] and uses (.indexOf coll item) to call insert-at....
10:11	justin_smith	so you have a vector of maps, and a seq of maps, and your reduce is to take each item in the seq of maps and find its position in the vector and then...
10:12	tgoossens	in leiningen with ':aot' how do I set two values?
10:13	justin_smith	tgoossens: so you have two totally unrelated namespaces that should be aot compiled? aot is transitive, so aot compiling an ns also aot compiles all its deps
10:13	wes__	move-up takes a single map and a vector of maps, finds the index of the item in the vector and produces a new vector of maps in which the item resides at (dec index)
10:13	hyPiRion	tgoossens: what do you mean by two values? :aot [myns.first myns.second] will compile both namespaces, regardless of their dependency to one or another
10:13	tgoossens	hyPiRion,
10:14	justin_smith	wes__: OK, that should totally work
10:14	tgoossens	hyPiRion, That is what i mean
10:14	hyPiRion	ah, nice
10:14	tgoossens	thanks :)
10:14	wes__	so, (reduce move-up seq-of-items vec-of-maps) ??
10:14	lazybot	wes__: Uh, no. Why would you even ask?
10:15	justin_smith	wes__: the vec should come before the seq
10:15	justin_smith	since you can't update a seq by index
10:16	wes__	ok, i'll give it a go.
10:16	justin_smith	and more generally, reduce takes its accumulator before the sequence it walks
10:20	Olajyd_	Please how can I compare date-values in clojure to determine which is greater?
10:20	justin_smith	Olajyd_: compare
10:20	justin_smith	,(java.util.Date. 0)
10:20	clojurebot	#inst "1970-01-01T00:00:00.000-00:00"
10:20	justin_smith	,(java.util.Date.)
10:20	clojurebot	#inst "2015-08-05T14:21:01.504-00:00"
10:21	justin_smith	,(compare (java.util.Date.) (java.util.Date. 0))
10:21	clojurebot	1
10:21	pbx	nice demo justin_smith
10:21	justin_smith	heh, thanks
10:23	gfredericks	$google gfredericks compare
10:23	lazybot	[gfredericks (Gary Fredericks) · GitHub] https://github.com/gfredericks
10:23	gfredericks	well https://github.com/gfredericks/compare
10:24	gfredericks	if you don't like writing your own -1/0/1 logic
10:24	justin_smith	gfredericks: handy!
10:24	oddcully	and if you don't need it for sorting, there is also .before/.after
10:24	gfredericks	justin_smith: !!!
10:25	wes__	So, I tried this and it gives a vector of vector of vector of maps
10:26	sdegutis	Given (defn foo [x y z] ...) and (defn bar [x y] (foo x y z)), how can I redefine bar so to remove the parameter redundancy?
10:27	sdegutis	Hi.
10:29	sdegutis	I thought it would have something to do with partial, but nope.
10:29	wes__	(move-up 'b ['a 'b 'c]) => [b a c]
10:29	justin_smith	wes__: (defn move-up [v i] (let [pos (.indexOf v i)] (if (pos? pos) (-> v (assoc pos (v (dec pos))) (assoc (dec pos) i)) v)))
10:29	justin_smith	wes__: needed the if for cases where i is not in the vec, or i is already at position 0
10:30	sdegutis	Clearer definitions are probably (defn foo [x y z] ...) and (defn bar [x y] (foo x y "some z")),
10:30	justin_smith	,(defn move-up [v i] (let [pos (.indexOf v i)] (if (pos? pos) (-> v (assoc pos (v (dec pos))) (assoc (dec pos) i)) v)))
10:30	clojurebot	#'sandbox/move-up
10:30	justin_smith	,(move-up 'b '[a b c])
10:30	clojurebot	#error {\n :cause "No matching method found: indexOf for class clojure.lang.Symbol"\n :via\n [{:type java.lang.IllegalArgumentException\n :message "No matching method found: indexOf for class clojure.lang.Symbol"\n :at [clojure.lang.Reflector invokeMatchingMethod "Reflector.java" 53]}]\n :trace\n [[clojure.lang.Reflector invokeMatchingMethod "Reflector.java" 53]\n [clojure.lang.Reflector invo...
10:30	justin_smith	,(move-up '[a b c] 'b)
10:30	clojurebot	[b a c]
10:30	justin_smith	oops I flibbed your args
10:30	justin_smith	but it works otherwise :)
10:30	perplexa	:D
10:32	justin_smith	shorter: (defn move-up [v i] (let [pos (.indexOf v i)] (if (pos? pos) (assoc v pos (v (dec pos)) (dec pos) i) v)))
10:33	justin_smith	wes__: I recommend that arg order, because the idiom in clojure is that the associative item comes first
10:33	justin_smith	wes__: and even more important, the rules of reduce says the accumulator (the vector) must be the first arg
10:34	perplexa	,(move-up '[a b c] 'c)
10:34	clojurebot	#error {\n :cause "Unable to resolve symbol: move-up in this context"\n :via\n [{:type clojure.lang.Compiler$CompilerException\n :message "java.lang.RuntimeException: Unable to resolve symbol: move-up in this context, compiling:(NO_SOURCE_PATH:0:0)"\n :at [clojure.lang.Compiler analyze "Compiler.java" 6704]}\n {:type java.lang.RuntimeException\n :message "Unable to resolve symbol: move-up i...
10:34	justin_smith	,(defn move-up [v i] (let [pos (.indexOf v i)] (if (pos? pos) (assoc v pos (v (dec pos)) (dec pos) i) v)))
10:34	clojurebot	#'sandbox/move-up
10:34	perplexa	,(move-up '[a b c] 'c)
10:34	clojurebot	[a c b]
10:34	justin_smith	now try - clojurebot is forgetful :)
10:34	perplexa	hehe
10:34	perplexa	alzheimerbot ;p
10:35	wes__	oh, so to write a function that is reducable, I've got to have the accumulator as the first argument?
10:35	justin_smith	yes, always
10:35	Olajyd	@justin_smith: How can i comapre date values in clojure?
10:35	wes__	Thanks. That's a great help.
10:35	sdegutis	Wait!
10:35	sdegutis	Is this even possible!?
10:35	justin_smith	Olajyd: didn't I just show that above?
10:36	justin_smith	Olajyd: the compare function will return -1, 0, or 1 depending on how two dates compare
10:36	sdegutis	I actually have this: (defn change [db entity attr value] ...) and (defn change-text [db entity value] (change db entity :text value))
10:36	sdegutis	Can I simplify the definition of change-text at all?
10:37	sdegutis	I tried using partial but I must be doing it wrong because that helps naught.
10:37	sdegutis	*not
10:37	justin_smith	sdegutis: maybe flatland/useful has some kind of flipped partial
10:37	justin_smith	sdegutis: partial works from the wrong direction for your code
10:38	sdegutis	Ahh right, I have to fill in the innards when I don't have them yet.
10:38	Olajyd	@justin_smith.. I’m sorry can’t find the compare function, is it the `move-up` function you wrote?
10:38	justin_smith	Olajyd: it's called "compare"
10:38	oddcully	,(doc compare)
10:38	clojurebot	"([x y]); Comparator. Returns a negative number, zero, or a positive number when x is logically 'less than', 'equal to', or 'greater than' y. Same as Java x.compareTo(y) except it also works for nil, and compares numbers and collections in a type-independent manner. x must implement Comparable"
10:38	justin_smith	Olajyd: I literally showed how to use compare right after you asked the first time
10:39	justin_smith	,(compare (java.util.Date.) (java.util.Date. 0))
10:39	clojurebot	1
10:39	justin_smith	that result means the first one was greater
10:39	Olajyd	@justin_smith I’m sorry i got disconnected when I asked the first time :)
10:39	justin_smith	oh, OK
10:40	justin_smith	I have joins/parts/disconnects turned off on this channel, it's too noisy otherwise
10:40	oddcully	Olajyd: there is also a log: http://clojure-log.n01se.net/
10:41	Olajyd	@oddcully Thanks for helping me out on saturday :)
10:42	oddcully	yw, but i forgot ;)
10:43	Olajyd	@oddcully : I have a vector of dates in the format (yyyy/MM/dd) and I want to be able to get the maximum date using `reduce`
10:43	justin_smith	Olajyd: you could also use max-key
10:43	gilliard	Olajyd: that date format will sort lexicographically, if they're strings.
10:44	justin_smith	, (apply max-key #(.getTime %) [(java.util.Date. 0) (java.util.Date. 1) (java.util.Date. 2)])
10:44	Olajyd	really @gilliard
10:44	clojurebot	#inst "1970-01-01T00:00:00.002-00:00"
10:44	justin_smith	Olajyd: the above will always return the largest date in a sequence
10:45	oddcully	dates in the "formst X" are just strings right?
10:45	justin_smith	oh, I thought you meant you had real dates (as in java.util.Date.)
10:45	gilliard	,(max ["2015/5/2" "2015/11/10" "2010/20/9"])
10:45	clojurebot	["2015/5/2" "2015/11/10" "2010/20/9"]
10:45	gilliard	,(apply max ["2015/5/2" "2015/11/10" "2010/20/9"])
10:45	clojurebot	#error {\n :cause "java.lang.String cannot be cast to java.lang.Number"\n :via\n [{:type java.lang.ClassCastException\n :message "java.lang.String cannot be cast to java.lang.Number"\n :at [clojure.lang.Numbers gt "Numbers.java" 229]}]\n :trace\n [[clojure.lang.Numbers gt "Numbers.java" 229]\n [clojure.lang.Numbers max "Numbers.java" 4027]\n [clojure.core$max invokeStatic "core.clj" 1091]\n ...
10:45	justin_smith	gilliard: first of sort
10:45	oddcully	shouldn't this be just be the last of a string sort?
10:45	gilliard	justin_smith: you got it ;)
10:45	justin_smith	oddcully: oh right, or first of a reversed sort
10:46	justin_smith	or a reduce using compare (compare works on strings)
10:46	oddcully	at least of MM/dd is actually used (leading zeros)
10:48	justin_smith	,(reduce #(case (compare % %2) 1 % -1 %2 0 %1) ["1970/02/11" "1914/03/01" "0000/00/00"])
10:48	clojurebot	#error {\n :cause "No matching clause: 6"\n :via\n [{:type java.lang.IllegalArgumentException\n :message "No matching clause: 6"\n :at [sandbox$eval102$fn__103 invoke "NO_SOURCE_FILE" 0]}]\n :trace\n [[sandbox$eval102$fn__103 invoke "NO_SOURCE_FILE" 0]\n [clojure.lang.PersistentVector reduce "PersistentVector.java" 323]\n [clojure.core$reduce invokeStatic "core.clj" 6517]\n [clojure.core$re...
10:48	justin_smith	err
10:48	justin_smith	compare can return 6, OK
10:49	oddcully	`Returns a negative number, zero, or a positive number...`
10:49	gilliard	ye just 0, more than 0, or less than 0
10:49	justin_smith	,(reduce #(if (pos? (compare % %2)) %1 %2) ["1970/02/11" "1914/03/01" "0000/00/00"])
10:49	clojurebot	"1970/02/11"
10:49	Olajyd	thanks @justin_smith :)
10:52	justin_smith	Olajyd: the funny part is that my initial answer still works even though I was wrong about your data type, because compare is just that general
10:52	Olajyd	@justin_smith the solution works for me
10:52	Olajyd	:)
10:52	oddcully	random fun wikipedia fact: on 1914-03-01 china joined the Universal Postal Union
10:54	justin_smith	haha
10:58	wes__	justin_smith Using your move-up works (move-up [f1 f2 f3] f2) => [f2 f1 f3] but (reduce [f1 f2 f3] '(f2 f3)) => [f1 f2 f3] where I expect [f2 f3 f1]
10:59	justin_smith	wes__: hmm
10:59	justin_smith	wes__: it works?
11:00	justin_smith	, (defn move-up [v i] (let [pos (.indexOf v i)] (if (pos? pos) (assoc v pos (v (dec pos)) (dec pos) i) v)))
11:00	clojurebot	#'sandbox/move-up
11:00	justin_smith	, (reduce move-up '[f1 f2 f3] '(f2 f3))
11:00	clojurebot	[f2 f3 f1]
11:04	wes__	justin_smith yeah, it works thanks. I just learned that '(f2 f3) is not the same as (list f2 f3)
11:05	justin_smith	oh, yeah :)
11:06	justin_smith	[f2 f3] works too - reduce can accept vectors, anything that seq works on
11:41	wes__	So, I got move-down working as well, but I discovered that the order of the items in the reduce function is important. How do I sort a seq by their index in a vector?
11:44	wes__	(sort #(.indexOf '[f1 f2 f3 f4 f5] %) '(f3 f5 f1))
11:45	justin_smith	,(sort-by #(.indexOf '[f1 f2 f3 f4 f5] %) '(f3 f5 f1))
11:46	clojurebot	(f1 f3 f5)
11:46	jonathanj	hrm, how would i write a function that wraps another function and logs its arguments to a file? i tried: (defn log-to [path f] (with-open [fd (writer path)] (fn [s] (spit fd s) (f s))))
11:46	jonathanj	but i guess (with-open) closes as soon as log-to returns
11:46	justin_smith	jonathanj: yeah, only use with-open if you want to close the file in that block
11:47	justin_smith	jonathanj: otherwise you can use .write, and make your own arrangements to close the file...
11:47	wes__	Missed it by `that` much. thanks
11:47	justin_smith	wes__: yes, you were quite close
11:47	jonathanj	okay, well as a crappy interim measure i can just open the file and write to it everytime the inner function is invoked, how do i open a file for appending?
11:47	justin_smith	wes__: do you ever look at http://conj.io ?
11:48	justin_smith	jonathanj: it's an optional arg to writer
11:48	justin_smith	,(doc clojure.java.io/writer)
11:48	clojurebot	"([x & opts]); Attempts to coerce its argument into an open java.io.Writer. Default implementations always return a java.io.BufferedWriter. Default implementations are provided for Writer, BufferedWriter, OutputStream, File, URI, URL, Socket, and String. If the argument is a String, it tries to resolve it first as a URI, then as a local file name. URIs with a 'file' protocol are converted to local...
11:48	wes__	justin_smith no. Thanks for showing it to me.
11:49	jonathanj	i'm reading the docs for writer but there is apparently no mention of what the arguments are?
11:49	justin_smith	wes__: I asked because with the way conj.io is layed out, you likely would have found sort-by :)
11:49	jonathanj	the optional arguments, i mean
11:49	justin_smith	jonathanj: hmm, I know they are around somewhere
11:49	jonathanj	looks like it's just :append
11:49	jonathanj	(looking at an example on conj.io)
11:50	justin_smith	jonathanj: source reveals it https://github.com/clojure/clojure/blob/master/src/clj/clojure/java/io.clj#L69
11:50	jonathanj	:append true, at least
11:50	justin_smith	jonathanj: useful site :)
11:51	jonathanj	what are the differences between conj.io and clojuredocs?
11:51	justin_smith	jonathanj: different maintainers, conj.io is more ambitious
11:51	jonathanj	how so?
11:52	justin_smith	it wants to document libs outside of clojure itself eventually
11:52	jonathanj	ah, nice
11:52	justin_smith	jonathanj: arrdem and andyf could probably tell you about the differences in more detail (they maintain the two sites)
12:00	jonathanj	i remember some clojure library that implemented a grammar-based parser based on BNF (or something that was really close to it), but i can't remember the name of the library
12:01	jonathanj	oh instaparse
12:01	justin_smith	instaparse?
12:01	blkcat	instaparse?
12:01	clojurebot	instaparse is lovely
12:01	clojurebot	instaparse is lovely
12:01	justin_smith	hahaha
12:01	blkcat	i use instaparse and can confirm that it rocks
12:01	justin_smith	^ the beginning of a musical about parsing
12:01	justin_smith	(to the tune of "monorail" of course)
12:26	jonathanj	so if i have an instaparse rule like `word = letter+ <letter> = #'[a-zA-Z]'` i end up with :word ["h" "e" "l" "l" "o"]
12:27	jonathanj	it looks like the preferred way to turn that into a string is `(transform {:word str} ...)`?
12:27	jonathanj	i can't indicate this in the grammar some how?
12:28	sdegutis	I just used clojure.data/diff
12:28	sdegutis	and clojure.set/map-invert, I bet you didn't even know it existed!
12:30	jonathanj	the problem i guess is that (transform {:word str} ...) turns [:word ["h" "i"]] into "hi", i'd prefer not to destroy the tag
12:32	alex_engelberg	jonathanj: I'm missing context (just joined channel) but I may be able to help with your instaparse problem
12:32	jonathanj	alex_engelberg: hello!
12:32	jonathanj	alex_engelberg: firstly, instaparse is a wonderful piece of software, thank you very much
12:33	alex_engelberg	thank you! and thank YOU for using it! :)
12:33	sdegutis	My task this week is to write a parser via a purely immutable state machine.
12:34	alex_engelberg	I'm an IRC noob, is there a way to look at previous messages before I joined?
12:34	alex_engelberg	Or is the solution to just always stay logged in? :)
12:34	sdegutis	alex_engelberg: neither
12:34	arohner	alex_engelberg: yes, stay logged in. There are also bot loggers
12:34	sdegutis	http://logs.lazybot.org/irc.freenode.net/%23clojure
12:34	sdegutis	alex_engelberg: just use that link. only works for here.
12:34	jonathanj	alex_engelberg: i'd like not to destroy the tag being transformed
12:34	arohner	http://clojure-log.n01se.net/
12:34	oddcully	alex_engelberg: http://clojure-log.n01se.net/
12:34	sdegutis	arohner: I prefer lazybot's
12:34	alex_engelberg	Thanks
12:34	oddcully	alex_engelberg: and instaparse is fscking awesome!
12:35	jonathanj	alex_engelberg: (insta/transform {:word str} [:word "h" "i"]) ends up losing the structure
12:35	sdegutis	oddcully: instaparse has nothing to do with checking or interactively repairing filesystem consistency
12:35	alex_engelberg	jonathanj: you want [:word "hi"]?
12:35	jonathanj	i realise i can probably do something like {:word (put-the-tag-back :word str)} but i'd like to avoid repeating myself if it's possible
12:36	jonathanj	alex_engelberg: yes
12:36	alex_engelberg	You could cleverly write your grammar with extra layers that are transformed in different ways
12:36	alex_engelberg	word = word2
12:36	alex_engelberg	word2 = #'[a-z]+'
12:36	alex_engelberg	And just transform word2
12:36	jonathanj	so produce something like [:word [:letters "h" "i"]] and transform letters with str?
12:37	alex_engelberg	yes.
12:38	alex_engelberg	I don't know enough about instaparse innards to know how much slower that would make the parser. The "put-the-tag-back" transformer would be the best place to do that work, efficiency-wise. I'd say it's probably a negligible difference though.
12:39	jonathanj	i guess that could work
12:39	jonathanj	thanks
12:40	alex_engelberg	jonathanj: no problem
12:40	alex_engelberg	I'm seeing a potential bug with clojure.tools.reader and cljs.tools.reader.
12:41	alex_engelberg	(clojure.tools.reader/read-string "018") => null pointer exception
12:42	alex_engelberg	Note that this is an invalid octal number, and throws a more user friendly number format exception in clojure.lang.LispReader.
12:42	alex_engelberg	On cljs (and I'm not sure this is a bug or a feature), (cljs.tools.reader/read-string "018") => 18
12:42	alex_engelberg	In other words, invalid octal numbers are simply parsed as decimal.
12:45	alex_engelberg	For comparison, (clojure.tools.reader/read-string "017") => 15, and same with cljs
13:25	puredanger	you could use that as a really weird platform detector
13:26	Bronsa	alex_engelberg: definitely a bug
13:29	justin_smith	puredanger: heh, for when cljc is just too easy
13:34	Bronsa	alex_engelberg: fixed in tools.reader master
13:57	jonathanj	i know that ztellman's libraries aren't terribly popular here but can anyone suggest why i might want to use core.async over manifold streams?
13:58	justin_smith	jonathanj: what makes you think his libs are unpopular?
13:58	justin_smith	jonathanj: core.async is inherently "push", manifold can do push or pull
13:58	justin_smith	(that's one reason)
13:58	jonathanj	justin_smith: i just don't see a lot of conversation around them here
13:59	jonathanj	and the mailing lists are very low volume
13:59	jonathanj	well, the aleph list anyway, i don't even think there are lists for his other libraries
13:59	justin_smith	jonathanj: ztellman did a great talk at the last conj comparing manifold, core.async, and prismatic/graph that explains them all on a continuum of design
13:59	amalloy	jonathanj: higher volume than most other clojure libraries, which have no ML at all
14:00	jonathanj	justin_smith: oh that sounds pretty great, i don't suppose you have a link or title of the talk for me?
14:00	justin_smith	jonathanj: if you really want to understand how manifold relates to core.async, I'd check out that talk - it's on youtube
14:00	amalloy	justin_smith: i don't quite understand what you mean by core.async being push-only
14:00	justin_smith	$google ztellman manifold clojure conj
14:00	lazybot	[Clojure/conj 2014 Notes - Forays into simplicity] http://eigenhombre.com/clojure/2014/11/27/conj-notes/
14:00	amalloy	like you can only push things into channels, and you can only pull things out, right?
14:01	jonathanj	justin_smith: i'm guessing that's not the one?
14:01	justin_smith	jonathanj: it's on youtube, one moment
14:01	jonathanj	https://www.youtube.com/watch?v=1bNOO3xxMc0 ?
14:02	justin_smith	nope, that's from clojure/west
14:02	justin_smith	jonathanj: this one https://www.youtube.com/watch?v=3oQTSP4FngY
14:02	jonathanj	justin_smith: thank you
14:04	justin_smith	amalloy: I wish I could remember the concrete details (I should have made a blog post about this), I was making an app where a lazy-seq was abstracting over input from a core.async channel, and it was "buffering" an item at a time
14:05	amalloy	as opposed to waiting until you seq to <! an item?
14:05	justin_smith	amalloy: I actually talked to ztellman about why this happened, and the explanation ended up being that lazy-seqs were a "pull" abstraction, and core.async is a "push" abstraction
14:06	amalloy	yes, that i agree with
14:06	justin_smith	and manifold is more flexible (I ended up going another route entirely in our app though)
14:06	justin_smith	now I want to make a minimal example (another thing on my "get around to it" list)
14:08	jonathanj	in the first 2 minutes of both of those talks, ztellman says "we don't just write software to raise the ambient temperature of the room"... haha
14:44	eriktjacobsen	Any critiques / improvements on a pattern that will take a list of maps, search for partial duplicates and remove them? So perhaps matching dupes on 2-3 keys, with option to customize which item is picked as the final de-duped one?
14:44	eriktjacobsen	This is what I came up with: (defn remove-dupes [key-fn sort-fn compare-fn items]
14:44	eriktjacobsen	(->> (group-by key-fn items)
14:44	eriktjacobsen	(map (fn [[_ entries]]
14:44	eriktjacobsen	(first (sort-by sort-fn compare-fn entries))))
14:44	eriktjacobsen	(remove nil?)
14:44	eriktjacobsen	flatten))
14:44	oddcully	first concern: not using refheap, pastebin, ...
14:45	eriktjacobsen	http://pastebin.com/EDpr1pHy
14:45	eriktjacobsen	Will remember
14:45	oddcully	cool
14:46	justin_smith	eriktjacobsen: you may want to use group-by, if you have a function that will return the same result for all maps that should be considered dups (maybe select-keys ?)
14:47	justin_smith	,(group-by #(select-keys % [:a :b]) [{:a 0 :b 1 :c 2} {:a 1 :b 1 :c 2} {:a 0 :b 1 :c 42}])
14:47	eriktjacobsen	group-by is the first call actually, I’m often passing in something like “#(clojure.string/join "-" ((juxt :partner :year :month) %))”
14:47	clojurebot	{{:a 0, :b 1} [{:a 0, :b 1, :c 2} {:a 0, :b 1, :c 42}], {:a 1, :b 1} [{:a 1, :b 1, :c 2}]}
14:48	eriktjacobsen	Oh I don’t have to string that / join do I… interesting right
14:48	amalloy	first of sort is not right in many scenarios; are you sure you can't use max-key?
14:48	justin_smith	right, you can use anything as a key in clojure
14:48	sdegutis	I'm back.
14:49	justin_smith	eriktjacobsen: also, use mapcat identity instead of remove nil / flatten
14:49	justin_smith	it replaces both, and is better behaved
14:49	eriktjacobsen	amalloy: I was intending to sometimes pass in something as simple as pulling an integer key and using < or > as compare, but also wanted to pass in ability to use a string or regex type compare to sort them…. so max-key would seem to force that
14:51	eriktjacobsen	I’ll look into that (actually the remove nil / flatten I think is un-needed since this one does first, which will always return a record) this was actually from separate version that instead of outputting list of de-duped, it instead gave list of stuff to REMOVE (so I did a (when (> (count %) 1) (rest items))
14:51	eriktjacobsen	Will do that though since I need both version
14:52	hellofunk	are bitwise operations supported on 64bit integers in clojure
14:53	eriktjacobsen	justin_smith: I dont think I knew that… could you explain how mapcat identity removes nils ? isn’t (identity nil) = nil? I would expect a single nil in the output
14:54	hiredman	eriktjacobsen: it is, he meant apply concat
14:55	hiredman	or just turn the map in to a mapcat if the function returns nil or a collection
14:56	eriktjacobsen	hiredman it does actually work though… it flattens and removes the nils. I just dont understand why. http://pastebin.com/ArDbeyyW
15:00	eriktjacobsen	oh duh concat doesn’t concat nils…. totally forgot. that seems like odd behavior though. interesting though
15:02	eriktjacobsen	Thanks amalloy justin_smith. Learn something new everyday
15:05	TEttinger	hellofunk: yes. I think the default is to use long (64-bit signed) integers
15:05	kwladyka	REPL can affect memory usage in some way?
15:05	kwladyka	instead of running directly from jar file?
15:05	TEttinger	,(bit-or (bit-shift-left 0xFFFFFFFF 15) 0xFFFFFFFF)
15:05	clojurebot	140737488355327
15:06	kwladyka	what i see yes, but i am not sure
15:06	TEttinger	kwladyka: yeah, the REPL has to store previous evaluated arguments as 1, 2, *3 etc.
15:07	kwladyka	is a way to test app usage memory without compile it to jar?
15:08	TEttinger	I think it also needs to compile code differently, but I'm not sure how. jar (or uberjar for executables, or whatever war/uberwar stuff EE webdev needs) should probably be the default when testing performance if you're deploying that way
15:11	TEttinger	(I think it's likely that running a jar with the right memory settings, -Xms64m to start small and garbage collect quickly if not using all of the allocated memory, -Xmx512m or whatever the max you might need and can support is, mess with GC options, make sure you're using --server if you need speed, --client may help with memory at the expense of speed...)
15:11	TEttinger	or is it -server
15:12	TEttinger	anyway, running a jar with the right memory settings is very different from running a jar with very wrong memory settings
15:12	TEttinger	-Xms16G
15:12	TEttinger	"why is my jarva using so much rams?"
15:13	kwladyka	TEttinger, i use profiler to check memory usage so i see not only how many is allocated, but how many is really used
15:13	kwladyka	but as i see REPL affect results as i see
15:13	kwladyka	but i am not sure, i am researching it now :)
15:15	kwladyka	it can be noob question, but.. if i will do lein compile can i run app without doing lein uberjar?
15:15	TEttinger	I'm guessing uberjar is pretty slow for your project?
15:16	TEttinger	$google leiningen faster
15:16	lazybot	[Faster · technomancy/leiningen Wiki · GitHub] https://github.com/technomancy/leiningen/wiki/Faster
15:17	TEttinger	clojurebot: slow \|no\| more! https://github.com/technomancy/leiningen/wiki/Faster
15:17	clojurebot	You don't have to tell me twice.
15:17	TEttinger	~slow
15:17	clojurebot	slow no more! https://github.com/technomancy/leiningen/wiki/Faster
15:17	sdegutis	I'm back again.
15:18	TEttinger	your nick is an anagram for degu sits. degus are kinda cute little creatures.
15:19	Bronsa	sdegutis: you don't have to announce it everytime
15:19	sdegutis	Bronsa: Phew, thanks.
15:20	TEttinger	Bronsa: I'm here currently
15:20	oddcully	~logs
15:20	clojurebot	logs is http://clojure-log.n01se.net/
15:21	oddcully	ah i knew it
15:21	TEttinger	sdegutis: they're a pretty good thing to have in your name. https://en.wikipedia.org/wiki/Degu#/media/File:Octodon_degus_-Artis_Zoo,_Netherlands-8b.jpg
15:21	amalloy	sdegutis just needs like one more letter to have a lot of fun anagrams
15:21	amalloy	duet siege
15:22	sdegutis	Oh man. Do I need to go back to /nick sed-utils?
15:22	TEttinger	Degus are extremely intelligent and have a good ability to solve problems. well there you go!
15:32	sdegutis	Is there a way to check if every item in a collection is equal besides (apply = coll) ?
15:33	amalloy	sure, there are lots of worse ways
15:33	gfredericks	what don't you like about (apply = coll)?
15:33	kwladyka	something is wrong with my profile file? https://www.refheap.com/58124c0debd9118eb4c6e7ab3 Warning: The Main-Class specified does not exist within the jar. It may not be executable as expected. A gen-class directive may be missing in the namespace which contains the main method.
15:33	amalloy	gfredericks: i'll tell you what i don't like about (apply = coll)
15:33	amalloy	but i bet you already know: it doesn't work on empty colls
15:34	gfredericks	I didn't know that would be it
15:34	amalloy	(i regard this as a bug in = but nobody really cares)
15:34	gfredericks	but I think I might understand why it does
15:34	opqdonut	yeah (=) should be true
15:34	opqdonut	I agree
15:34	gfredericks	,(<)
15:34	clojurebot	#error {\n :cause "Wrong number of args (0) passed to: core/<"\n :via\n [{:type clojure.lang.ArityException\n :message "Wrong number of args (0) passed to: core/<"\n :at [clojure.lang.AFn throwArity "AFn.java" 429]}]\n :trace\n [[clojure.lang.AFn throwArity "AFn.java" 429]\n [clojure.lang.RestFn invoke "RestFn.java" 399]\n [sandbox$eval25 invokeStatic "NO_SOURCE_FILE" 0]\n [sandbox$eval25 i...
15:34	opqdonut	(<) is less well defined than (=)
15:34	gfredericks	why is that?
15:35	opqdonut	or that's my knee-jerk reaction anyway, let me think
15:35	amalloy	gfredericks: last time this came up somebody claimed it is a little bit awkward if you extend this to the < family of functions, because then < and (complement >=) are no longer the same
15:35	amalloy	but on reflection this is totally bunk, because they're already not the same on anything but 2 arguments
15:36	opqdonut	indeed
15:36	opqdonut	ok, I guess (=) and (<) are actually pretty symmetric. if you have the n-ary versions you should also have the 0-ary version
15:36	gfredericks	I've always thought of these arities as being related to recursive definitions of the functions
15:37	gfredericks	+ and * can get all the way to 0 args because they are monoids
15:37	gfredericks	(in contrast with / and -)
15:37	sdegutis	What's the opposite of some
15:38	gfredericks	and and or are also monoids I think?
15:38	amalloy	gfredericks: yes, they are
15:38	gfredericks	so you can't get 0 args for = and < just by the monoid reasoning, it'd have to be something else
15:38	amalloy	gfredericks: the problem is that some and every? do extend down to empty collections, and (apply = coll) "should" be the same as (every? #(= % (first coll)) coll)
15:38	hiredman	well
15:39	gfredericks	in haskell that'd throw an exception
15:39	amalloy	gfredericks: i don't think so
15:39	gfredericks	for an empty list
15:39	amalloy	no, because every undefined [] = true
15:39	amalloy	True
15:39	gfredericks	well arguably that has more to do with how the code is structured
15:40	gfredericks	if you wrote it (let [x (first coll)] (every? #(= % x) coll))
15:40	amalloy	gfredericks: still would work fine in haskell, because lazy
15:40	gfredericks	I feel like this is a meaningful point somehow
15:40	amalloy	you can't make that throw, because you can't possibly use the value if the list is empty
15:40	sdegutis	Is there a shorter way of (not (some f xs)) ?
15:40	gfredericks	amalloy: sure but the language being lazy is a side detail here
15:41	gfredericks	sdegutis: not-any?
15:41	sdegutis	Ahhh.
15:41	sdegutis	Silly lack of consistent naming.
15:41	amalloy	i don't think so. if you're claiming that my proposed equivalent would throw an exception in haskell, it seems like the way haskell behaves is pretty relevant
15:41	sdegutis	Earlier I looked for any? and couldn't find it. Turns out it was some.
15:41	kwladyka	seriously what am i doing wrong with lein uberjar, why am i gettign this error? All looks like is should in poject.clj https://www.refheap.com/58124c0debd9118eb4c6e7ab3
15:41	opqdonut	sdegutis: because it returns non-booleans too
15:41	Bronsa	sdegutis: any? would imply a boolean return.
15:41	gfredericks	amalloy: I'm appealing to one part of the behavior of haskell and not the other part :P
15:42	opqdonut	but yeah it trips people up
15:42	sdegutis	Ahhh right, Clojure makes types multi-task.
15:43	amalloy	gfredericks: so your argument seems to be that in two consistently-defined languages, my suggested identity would hold, but in a theoretical bad language that's a mix of both, a restructured version of my identity would throw an exception
15:43	amalloy	(eg, in java you would be right)
15:43	gfredericks	so let's think about it recursively
15:44	gfredericks	if you add another element to an = expression, the expression is true if that element equals the "first" element in the expression and if the rest of them are equal
15:44	gfredericks	i.e. (= a b1 b2 ...) is (and (= a b1) (= b1 b2 ...))
15:44	gfredericks	and the base case is that (= bn) is true
15:44	sdegutis	Thanks gfredericks.
15:45	gfredericks	my point is that the natural base case in this formulation is 1 arg
15:45	gfredericks	and this works for all the ordering predicates
15:45	sdegutis	What's a striking way to test if coll contains :a or :b (or both)?
15:46	gfredericks	so adding a 0-arg version feels like an unrelated "alternate base case" or something
15:46	gfredericks	sdegutis: (some #{:a :b} coll)
15:46	sdegutis	Amazing.
15:46	sdegutis	Thanks gfredericks. You won twice in a row.
15:46	kwladyka	oh i have to use :gen-class ...
15:48	amalloy	gfredericks: doesn't apply to not=, right?
15:48	gfredericks	,(doc not=)
15:48	clojurebot	"([x] [x y] [x y & more]); Same as (not (= obj1 obj2))"
15:49	gfredericks	(not= a b1 b2 ...) is (or (not= a b1) (not= b1 b2 ...))
15:49	gfredericks	,(not= 42)
15:49	clojurebot	false
15:49	gfredericks	and the base case is (not= bn) is false
15:49	gfredericks	I just did that off the top of my head, hadn't thought about not=
15:49	gfredericks	so not sure if it makes sense
15:50	gfredericks	amalloy: I think a better approach to what I was trying to say w/ haskell would be "You can't formulate it that way mathematically"
15:51	gfredericks	e.g., with set theory
15:58	hiredman	isn't equivalence in math a binary operation?
15:58	hiredman	err
15:58	hiredman	relation
15:58	gfredericks	yeah
15:59	gfredericks	that doesn't stop you from making it variadic though
15:59	gfredericks	the question is does it make sense to have the (=) base case when you do
15:59	hiredman	does it make sense to have a base case (= b) ?
15:59	gfredericks	I think it makes as much sense as (+)
16:00	gfredericks	and I think (=) makes less sense
16:00	gfredericks	that's the side I'm arguing for anyhow
16:00	gfredericks	not gonna get in a fight about it
16:00	hiredman	and if (= b) makes sense even if = is a binary relation, then why doesn't (=) make as much sense?
16:01	gfredericks	well that's what I was trying to argue; in particular I think (+) => 0 is a "natural" base case for + and that (= b) => true is a "natural" base case for =
16:01	gfredericks	because they both have nice recursive definitions that use those base cases
16:01	gfredericks	I don't know of a recursive definition for = that uses (=) true as a base case
16:04	justin_smith	gfredericks: I guess there is (apply = c), which should return true if c is nil / empty
16:05	justin_smith	intuitively at least
16:05	amalloy	justin_smith: that was the base case of this discussion
16:05	justin_smith	amalloy: d'oh! shows me for replying before I catch up on the scrollback
16:06	amalloy	it seeems like gfredericks is arguing that the usual description of (apply = xs) as "are all the things in xs equal to each other" is incorrect
16:06	amalloy	because if you take that description it is obvious that (=) is true
16:07	hiredman	gfredericks: that is an interesting point
16:07	sdegutis	Thanks for all your help.
16:07	gfredericks	amalloy: I might argue that that english phrasing is a bit ambiguous about what the empty case means
16:07	gfredericks	dunno maybe not
16:07	gfredericks	english hard
16:08	kwladyka	used PS old gen <- if i have something like that in my app with 209 MB in profiler... what is it mean? Am i doing something wrong?
16:08	kwladyka	it is about memory
16:09	amalloy	i just realized i don't have to put up with this sass. i can just +b gfredericks
16:09	gfredericks	o_O
16:09	amalloy	it will be as foretold in the prophecies by andyf. amalloy will rule with an iron fist
16:10	hiredman	there exists an equivalence class E for all item x in list l where x is a member of E
16:12	gfredericks	hiredman: quoting from some formalization of something?
16:12	hiredman	no, trying to piece one together
16:13	hiredman	that seems to be a statement of equality which would allow for (=), but I forget all that stuff about which binders → existence of whatever
16:13	kwladyka	ech i totally don't know how to get conclusions from profiler :/
16:19	justin_smith	kwladyka: you could see if the allocated size gets bigger if you run the code twice, you could profile subprograms to try and narrow down what is allocating
16:19	hiredman	the tricky thing is, I don't think any language has first class equivalence classes, but you can define one given at least one member of the equivalence class and some kind of equality operator
16:20	hiredman	(which of course is circular, we are trying to define equality)
16:20	hiredman	so you end up with recursion that bottoms out with a single element
16:22	kwladyka	justin_smith, https://www.dropbox.com/sh/fekagh9kp77f057/AAC0dCeunm2MDt0qWRw8f4lda?dl=0 look at clojure-jar char vs scala char
16:23	kwladyka	justin_smith, in both i did 10 sec sleep before
16:23	kwladyka	justin_smith, both do the same...
16:23	kwladyka	justin_smith, i totally stack with that, i dont know how to get conclusion what is wrong
16:24	kwladyka	just no idea what to do now to solve that :/
16:26	justin_smith	ugh, what a terrible gallery
16:26	kwladyka	sorry, i dont know better to fast upload
16:27	oddcully	haha
16:27	justin_smith	kwladyka: it's OK, you didn't implement that gallery view, but it's terrible
16:27	kwladyka	justin_smith, :)
16:28	justin_smith	the biggest difference there is that with clojure you have the whole compiler and all its libs in heap, with scala you do not
16:28	kwladyka	why the same algorithm in scala is so fast and consume so less memory, it makes me sick
16:28	justin_smith	but that isn't going to cause your speed problem
16:29	kwladyka	justin_smith, but clojure-jar.png is for uberjar file
16:29	justin_smith	uberjar has the entirety of clojure in it
16:29	justin_smith	there is no standalone option with clojure, unlike scala
16:29	justin_smith	the feature simply doesn't exist
16:29	Bronsa	(inc puredanger) ;; thanks for CLJ-1093
16:29	lazybot	⇒ 62
16:30	puredanger	did you catch the outcome?
16:30	justin_smith	but the extra ram used by clojure itself is not the cause of your speed difference, beyond the few seconds it takes clojure to bootstrap itself
16:30	kwladyka	justin_smith, do you know what used PS old gen can mean? maybe if you will see the code?
16:30	justin_smith	kwladyka: I've looked at your code already, it's complicated and I have my own hard debugging to do
16:30	justin_smith	sorry
16:30	kwladyka	justin_smith, because of about 10 sec sleep before counting it shouldnt affect the time
16:31	kwladyka	justin_smith, but didnt see any technical anti-performance code? :)
16:32	Bronsa	puredanger: yes. not exactly what I was hoping for but I'm fine with it, it's consistent with the doc and CLJ-1460
16:32	puredanger	Bronsa: he also addressed your other question on the (defn ^{:tag foo} a [])
16:32	Bronsa	yup saw that too
16:32	kwladyka	justin_smith, any hints what more can i do t solve that? i dont have more ideas....
16:33	justin_smith	kwladyka: I've looked at your code multiple times already, I suggested the things I thought might be issues, but I really can't fix this performance issue for you
16:33	kwladyka	is it possible it is because of Clojure, not my bug? Just Clojure do this longer or something like that?
16:34	TimMc	gfredericks: Regarding (=), I like the invariant that remving an element from the input never turns the output from true to false.
16:34	kwladyka	justin_smith, each time code was improved, i did big step, but now i stack totally what can i do more, i rewrited algorithm to work like this one in scala, but even now performance is much worst
16:35	justin_smith	kwladyka: if you switch some of your data from vanilla hash-maps to defrecords (which are in most ways identical in behavior to hash-maps, so it won't be a big change to your code) the profiler might give you easier to use data
16:35	TimMc	gfredericks: Or put more generally, "= returns true iff no two inputs are unequal" -- and if there are no two inputs, it is vaciously true.
16:35	TimMc	*vacuously
16:35	kwladyka	justin_smith, anyway thank you so much for trying help me with that problem.
16:35	puredanger	Bronsa: meaning it now has behavior prior to direct linking
16:36	kwladyka	justin_smith, defrecords performance is better?
16:37	justin_smith	kwladyka: it shows up as a different datatype in your profiler
16:37	justin_smith	thus you can see where all that ram is going
16:37	kwladyka	justin_smith, oh
16:37	justin_smith	like which kind of object is being created to such excess (if that is in fact the issue). Also try CPU profiling, see which methods are doing the most work.
16:39	kwladyka	it is hard to say what is the problem, but for sure it consume too much memory vs scala solution
16:39	hiredman	https://gist.github.com/hiredman/2aa99f1c24634e0fd9de
16:39	Bronsa	puredanger: I think there's still a difference but it's probably not meaningful
16:40	kwladyka	i mean if it is CPU problem, shouldnt be....
16:40	kwladyka	CPU didnt cross 80% during all counting
16:40	justin_smith	kwladyka: I already told you why the ram usage is different, clojure loads the full compiler into your app at runtime, scala does not
16:41	sdegutis	For anyone here looking to practice Clojure or sharpen their Clojure skills, this is an excellent Java file for porting to pure Clojure using every Clojure technique in the book to shorten it by a huge degree: https://raw.githubusercontent.com/slagyr/latlngtz/master/src/latlngtz/TimezoneMapper.java
16:41	hiredman	so if any language had first class equivilance classes, it would be natural to define equality using them in a way where (=) would work, but having first class ecs seems very impractical, so what is left is the recursive definition of = which relies on (= b) working
16:41	hiredman	oops, deleted the wrong line (emacs repeats my inputs)
16:42	kwladyka	justin_smith, yes but anyway it consume too much memory, i am afraid it is connected with Used PS old gen, it can be some track, but i dont understand what it is :)
16:42	kwladyka	what can cause that
16:43	kwladyka	but maybe it is not my code but Clojure...
16:43	hiredman	and since you need a base case for (= b) adding another for (=) seems inelegant
16:43	Bronsa	puredanger: actually I'm not sure rettag is very useful right now? it seem to only accept stuff like (defn ^long x [] ..) which don't make sense at runtime since long is evaluated to #<clojure.core$long..>
16:44	Bronsa	I'll try to look into it if I have some time tomorrow and let you know
16:45	gfredericks	hiredman: "Do all these elements belong to one class?" ← doesn't make sense for no elements
16:46	hiredman	gfredericks: https://en.wikipedia.org/wiki/Universal_quantification#The_empty_set
16:46	justin_smith	kwladyka: if I start clojure.jar, with no other libs loaded (not even lein or nrepl) I see a vsz/rss of 7056368 86412
16:46	justin_smith	that's a baseline, it won't go smaller
16:47	gfredericks	hiredman: I'm talking about (->> coll frequencies count (= 1))
16:47	gfredericks	or group-by if you like
16:48	kwladyka	justin_smith, i am thinking more about maybe Clojure remember some outputs for some magic reasons
16:48	kwladyka	cash that for future for me :)
16:49	xificurC	hiccup, garden, sablono - all these are used to generate html/css on the fly? I thought the purpose is to have it defined in clojure, process the definitions and generate static files. Am I misinterpreting something here?
16:50	hiredman	sure, right, you can obviously write the code differently, and via church-turing and get something in some other logic that will do the same
16:50	justin_smith	xificurC: static is relative, you can make a compile time step that outputs your resources if there is no relevant run time input
16:51	kwladyka	xificurC, http://clojure.wladyka.eu/posts/2015-06-01-template-libraries.html you can read my opinion about template libraries
16:52	gfredericks	hiredman: maybe I'm just having trouble connecting (=) to equivalence classes; how do you phrase the question that (=) is asking in terms of equivalence classes?
16:53	hiredman	gfredericks: set theoretic notions of equality seem to be based on equivalence classes
16:54	hiredman	(seem to meaning I am not sure my understanding is correct, not casting doubt on the field)
16:54	xificurC	justin_smith: I see, although since there's no utility functions/macros written for this I take it it's not very common to do that
16:55	xificurC	doesn't computing the page hinder performance on the server?
16:55	xificurC	kwladyka: thanks, although it seems very biased
16:56	hiredman	so I guess I don't see the argument from some formalism that handling (= b) is valid but (=) is not
16:56	kwladyka	xificurC, because it is my opinion base on my own experience :)
16:57	amalloy	justin_smith: most of that vsize is mmapped files though, not taking up any real memory if other programs need it
16:58	amalloy	well, i don't know about "most". but a lot of
16:58	hiredman	structurally (= b) makes more sense, because it is a base case you need in this case, but why not handle a base case for (=) if it would make it easier for client code
17:00	gfredericks	hiredman: yeah I'm not saying clojure shouldn't change necessarily; though you might argue that all the theoretical hand-waving suggests that anybody calling (=) has a high probability of having done it by accident. but that's probably not true
17:00	gfredericks	should (not=) be false?
17:01	xificurC	impressive how 1 guy (weavejester) created so many well known web-related libraries, e.g. ring, compojure, hiccup
17:01	kwladyka	xificurC, yes but i guess he didnt do this alone
17:02	kwladyka	_guess_
17:02	hiredman	gfredericks: I dunno
17:02	hiredman	I guess? is there a reason it shouldn't be the negation of =?
17:03	gfredericks	well the argument for (=) seems to be "well I think it's obvious what it means" so I wondered if not= was the same way
17:03	gfredericks	where I isn't anybody in particular
17:03	hellofunk	TEttinger: i get an int out of range error if i try to go beyond 32 bits
17:04	hiredman	equality is very problematic
17:04	hiredman	I taught clojurebot a factoid about scala years ago, that was a quote from someone in #scala saying something like "we are so screwed on ="
17:04	TEttinger	hellofunk: code please
17:05	hiredman	I must owe that guy a beer
17:05	slester	hmm, splitting up my code is proving a bit difficult
17:05	gfredericks	hiredman: haha
17:05	hellofunk	actually the error is java.lang.IllegalArgumentException: Value out of range for int: 4294967295
17:05	TEttinger	cooooode please
17:05	TEttinger	are you calling int on a large number?
17:06	hiredman	~scala
17:06	clojurebot	scala is val foo = bar ~-> 45 <~< "Fred" %% x
17:06	TEttinger	use long if you need a 64-bit signed integer
17:06	slester	Do a lot of people have just one giant file with all the functions in it? Seems bad, but I can't separate them into namespaces because basically all the functions call each other
17:06	TEttinger	,(int 4294967295)
17:06	clojurebot	#error {\n :cause "Value out of range for int: 4294967295"\n :via\n [{:type java.lang.IllegalArgumentException\n :message "Value out of range for int: 4294967295"\n :at [clojure.lang.RT intCast "RT.java" 1198]}]\n :trace\n [[clojure.lang.RT intCast "RT.java" 1198]\n [sandbox$eval25 invokeStatic "NO_SOURCE_FILE" 0]\n [sandbox$eval25 invoke "NO_SOURCE_FILE" -1]\n [clojure.lang.Compiler eval "...
17:06	TEttinger	,(long 4294967295)
17:06	clojurebot	4294967295
17:07	hellofunk	TEttinger: ah, i see the problem now. it's the API i'm using that is apparently limited to 32 bits under the hood. if i do it at the repl, no problem over 32 bits
17:08	hellofunk	the stack trace reveals an intCast right before the out of range error
17:08	TEttinger	slester: that's a pretty general architecture problem. from my experience, games are particularly susceptible to architecture issues because of the need to have so many things affect the inherently mutable graphics code.
17:08	hefesto	Hi. I am new at Clojure and irc... so I'm doing this the right way (if not, please say so). I am trying to use clj-antlr (https://github.com/aphyr/clj-antlr) on a project, but I keep getting java.io.FileNotFoundException: Could not locate clj_antlr__init.class or clj_antlr.clj on classpath: , compiling:(date.clj:1:1). On project.clj I add the [clj-antlr "0.2.2"] dependency and lein repl shows the previous error. ¿Does anyone see what I'm doing wro
17:08	hefesto	ng?
17:08	TEttinger	hey hefesto
17:09	hefesto	so I hope I'm doing this the right way
17:09	slester	TEttinger: yeah... :( I'm not sure what I can do about it though.
17:09	TEttinger	what are you requiring the clj-antlr dep as in your date.clj file?
17:09	hefesto	yes
17:09	hefesto	(ns com.bm.bmi.date
17:09	hefesto	"Parse dates using DateExpr.g4 grammar and ANTLR"
17:09	hefesto	(require ['clj-antlr.core :as 'antlr]))
17:09	xificurC	paste your date.clj into a pastebin
17:10	hefesto	(ns com.bm.bmi.date
17:10	hefesto	"Parse dates using DateExpr.g4 grammar and ANTLR"
17:10	hefesto	(require ['clj-antlr.core :as 'antlr]))
17:10	hefesto	(defn foo
17:10	hefesto	"I don't do a whole lot."
17:10	hefesto	[x]
17:10	hefesto	(println x "Hello, World!"))
17:10	xificurC	hefesto: you're new to IRC, don't do that :)
17:10	TEttinger	hefesto:
17:10	TEttinger	~pastebin
17:10	clojurebot	pastebin how about refheap? https://www.refheap.com/
17:10	hefesto	ok.
17:10	hefesto	sorry
17:10	xificurC	if you have more than 1 line of code use a site to paste your code
17:11	hefesto	okay, sorry.
17:11	TEttinger	your require is incorrect for an ns
17:11	TEttinger	within the ns form, (:require [clj-antlr.core :as antlr])
17:12	TEttinger	you still need to have the parens match, I just did that one section of the 3rd line in the date
17:12	hefesto	I see
17:12	TEttinger	(require ['clj-antlr.core :as 'antlr]) ; this is correct if you're running it at the REPL, or in any part of a file that isn't the ns macro
17:13	xificurC	or (require '[clj-antlr.core :as antlr])
17:13	TEttinger	there's an in-depth guide here, hefesto http://blog.8thlight.com/colin-jones/2010/12/05/clojure-libs-and-namespaces-require-use-import-and-ns.html
17:14	TEttinger	(inc xificurC)
17:14	lazybot	⇒ 1
17:14	hefesto	thank you very much!!!
17:14	TEttinger	no prob, is it working?
17:14	xificurC	seems like (bad joke ahead) I'm the One
17:15	TEttinger	maybe in the next life
17:15	hefesto	repl started to work
17:15	hefesto	which i've been trying to do for a while
17:15	hefesto	so it's a huge success for just now.
17:16	hefesto	:)
17:16	TEttinger	woo
17:16	TEttinger	you're using lein repl , right?
17:16	hefesto	emacs cider right now
17:18	TEttinger	I'm always kinda disappointed how the official docs don't really say "use lein, please, it's the best way right now" when talking about project management. I don't use emacs, but I think the clojure tools for it all use lein internally for projects and deps?
17:18	TEttinger	there's boot, which is really meant for larger projects it seems from their site
17:24	Bronsa	puredanger: yeah I looked into it and it doesn't seem like rettag makes sense the way it is implemented now. it will only accept (defn ^long x ..) or (defn ^double x ..) but those are invalid tags
17:26	hefesto	<TEttinger> : I dont know what emacs use internally. I've tried it out with the lein repl and the error disappeared too :)
17:27	TEttinger	woo
17:29	puredanger	Bronsa: thx
17:31	michaniskin__	TEttinger: cider should work fine with boot btw
17:32	TEttinger	nice
17:32	michaniskin__	but for beginners lein is probably a better alternative because there is a lot of stuff on stackoverflow to copy/paste from
17:32	michaniskin__	which is pretty important if you're just learning the language
17:32	TEttinger	I just think boot makes sense as a thing to transition to if a project becomes unmanageable with lein. is boot able to produce uberjars?
17:32	michaniskin__	sure
17:33	michaniskin__	it can do all the things you need
17:33	TEttinger	(is it faster at compiling at lein? pretty please?)
17:33	michaniskin__	haha no, boot is more about correctness and sanity
17:33	TEttinger	pfft
17:33	TEttinger	you know what I just wrote?
17:33	michaniskin__	so aggressive caching isn't done unless we have a solid way to invalidate cache
17:34	TEttinger	[DllImport("xbrz.dll", EntryPoint = "scale")] internal static extern int scale(int factor, UIntPtr src, UIntPtr trg, int srcWidth, int srcHeight, int colFmt, IntPtr nil = default(IntPtr), int yFirst = 0, int yLast = int.MaxValue);
17:35	michaniskin__	however, i think boot is a lot better for incremental compiles because of how it's organized, so that's what you generally use instead of persistent caches
17:35	justin_smith	~.
17:35	clojurebot	Cool story bro.
17:35	TEttinger	justin_smith: ?
17:36	justin_smith	TEttinger: that's the magic key sequence that closes ssh when it hangs
17:36	TEttinger	~~
17:36	clojurebot	Titim gan éirí ort.
17:36	justin_smith	TEttinger: my ssh connection to my irc session hangs when I connect from work
17:36	TEttinger	clojurebot: ~ is how you get factoids from me
17:36	clojurebot	You don't have to tell me twice.
17:37	TEttinger	~~
17:37	clojurebot	~ is how you get factoids from me
17:37	justin_smith	in this instance I had pushed page-up, and hit ~. because the page up was not scrolling. Turns out the ~. only works immediately after newlines
17:37	TEttinger	aw
18:21	sdegutis	Given [:a :b :c :d :e], what's a spectacular way to generate [[:a []], [:b [:a]], [:c [:a :b]], [:d [:a :b :c]], [:e [:a :b :c :d]]] ?
18:26	{blake}	sdegutis: Beat the CPU till it catches fire. Have the answers on a slip of flash paper in your pocket.
18:27	michaniskin__	,(reduce #(conj %1 (conj [%2 (vec (flatten (reverse (last %1))))])) [] [:a :b :c])
18:27	clojurebot	[[:a []] [:b [:a]] [:c [:a :b]]]
18:27	sdegutis	Hmm we may have a tie.
18:28	sdegutis	Both very good answers so far. But none quite spectacular... yet!
18:28	{blake}	I'd probably use a for.
18:28	justin_smith	,(first (reduce (fn [[acc prev] e] [(conj acc (vector e prev)) (conj prev e)]) [[][]] [:a :b :c :d]))
18:28	clojurebot	[[:a []] [:b [:a]] [:c [:a :b]] [:d [:a :b :c]]]
18:29	justin_smith	sdegutis: ^
18:29	sdegutis	I like the [[][]] in justin_smith's solution.
18:29	sdegutis	But still not spectacular.
18:29	{blake}	Nice.
18:30	{blake}	Write a macro that, when you start typing [:a :b...] it responds with "I see where you're going with this." and gives the result.
18:31	justin_smith	,(first (reduce (fn [[acc prev] e] [(conj acc [e prev]) (conj prev e)]) [[][]] [:a :b :c :d]))
18:31	clojurebot	[[:a []] [:b [:a]] [:c [:a :b]] [:d [:a :b :c]]]
18:34	sdegutis	{blake}: Haskell basically has that.
18:34	{blake}	heh
18:34	{blake}	(inc Haskell)
18:34	lazybot	⇒ 2
18:36	DerGuteMoritz	here's one without reduce: (let [x [:a :b :c :d :e]] (mapv vector x (map (comp vec drop-last) (range (count x) 0 -1) (repeat x))))
18:36	sdegutis	take 10 $ ['a','b' ..] // => "abcdefghij" (inc Haskell)
18:36	sdegutis	DerGuteMoritz: ugh, that's the one I was working on
18:37	sdegutis	cept I got distracted by magNITED states of merica
18:37	sdegutis	that rant was priceless
18:37	{blake}	Eh. I like justin_smith's better.
18:38	sdegutis	I'm still trying to understand DerGuteMoritz -- that in itself is major points!
18:38	sdegutis	Anyway thanks for always doing the hard parts of my day job for me you guys.
18:38	sdegutis	Especially you justin_smith.
18:38	DerGuteMoritz	heh yeah it's not exactly what I would use in production code
18:38	sdegutis	DerGuteMoritz: you'd be surprised how much FP is in production code
18:39	michaniskin__	,((fn [x] (zipmap x (mapv #(vec (take-while (partial not= %) x)) x))) [:a :b :c :d])
18:39	clojurebot	{:a [], :b [:a], :c [:a :b], :d [:a :b :c]}
18:39	DerGuteMoritz	just wanted to do one without reduce for a change
18:39	justin_smith	DerGuteMoritz: on a vector, never use drop-last, use pop instead
18:39	michaniskin__	derp
18:39	justin_smith	DerGuteMoritz: oh wait, that isn't a vector coming in, neverm ind
18:39	sdegutis	I need to loop over each item in a coll while testing against all previous elements in the same coll each time.
18:39	sdegutis	This is the most spectacular way to do it.
18:40	{blake}	michaniskin__: Oh, also nice.
18:40	DerGuteMoritz	justin_smith: also, pop doesn't take an argument of how many elements to pop - but we could use subvec instead perhaps
18:41	DerGuteMoritz	(when first mapping to vectors, right)
18:41	sdegutis	Still struggling to figure out how in the world DerGuteMoritz's solution works.
18:42	DerGuteMoritz	sdegutis: try this as a first step: (map drop-last (range (count x) 0 -1) (repeat x))
18:43	justin_smith	sdegutis: after you recall map is varargs, it's easy
18:43	DerGuteMoritz	the rest is just decoration ;-)
18:43	sdegutis	justin_smith: That's the fact I was planning to take advantage of actually.
18:43	sdegutis	In my try, all I got so far was ##(map vector (reverse coll) coll)
18:43	lazybot	java.lang.RuntimeException: Unable to resolve symbol: coll in this context
18:44	sdegutis	I mean ##(let [coll [:a :b :c :d :e]] (map vector (reverse coll) coll))
18:44	lazybot	⇒ ([:e :a] [:d :b] [:c :c] [:b :d] [:a :e])
18:44	sdegutis	I was gonna work from there.
18:44	sdegutis	And that's when I found this: https://www.youtube.com/watch?v=1L3eeC2lJZs
18:44	michaniskin__	iterate is the spectacularest
18:45	sdegutis	Which really slowed my progress down on the solution.
18:49	DerGuteMoritz	michaniskin__: hm nice idea
18:50	eblood	i have an uberjar that’s configured to start a main function that starts a backend process (started with java -jar dt-utils.jar).. i want to hop into a repl to use a function to test something, so using “java -cp dt-utils.jar clojure.main” I can get a repl, but none of the namespaces are initialized. what else do i need to do?
18:50	justin_smith	eblood: require your core namespace
18:50	justin_smith	eblood: remember that require from the repl is different from in ns forms
18:51	michaniskin__	,((comp (partial apply map vector) (juxt identity (comp reverse (partial take-while first) (partial iterate pop) pop))) [:a :b :c :d])
18:51	clojurebot	([:a [:a]] [:b [:a :b]] [:c [:a :b :c]])
18:51	michaniskin__	hehe
18:51	DerGuteMoritz	(let [x [:a :b :c :d :e]] (map vector x (cons [] (reverse (take (count x) (iterate pop x))))))
18:52	justin_smith	(inc michaniskin__)
18:52	lazybot	⇒ 1
18:52	justin_smith	that's a nice one
18:52	justin_smith	(inc michaniskin)
18:52	lazybot	⇒ 2
18:52	michaniskin__	i want my family coat of arms to have COMP JUXT PARTIAL APPLY in the crest
18:52	DerGuteMoritz	,(let [x [:a :b :c :d :e]] (map vector x (cons [] (reverse (take (count x) (iterate pop x))))))
18:52	clojurebot	([:a []] [:b [:a]] [:c [:a :b]] [:d [:a :b :c]] [:e [:a :b :c :d]])
18:52	sdegutis	My plan was to first turn [:a :b :c :d :e] into [[] [:a] [:a :b] [:a :b :c] ...]
18:53	sdegutis	Then I was just going to (partial mapv vector coll) that sucker.
18:53	DerGuteMoritz	ok that was fun, but now good night :-)
18:53	sdegutis	Dangit. I think DerGuteMoritz just did it again.
18:57	sdegutis	Aha! I knew it had something to do with repeatedly or repeat or iterate!
18:57	sdegutis	And yet, I feel oddly dissatisfied for not coming up with it myself.
18:57	sdegutis	I'm sorry #clojure. I'm sorry I asked you to do my day job for me. I just.. I had no idea that you would also get the /satisfaction/ from doing it.
18:58	sdegutis	Well, at the very least, I got to clean it up and make it beautiful:
18:58	sdegutis	,(let [coll [:a :b :c :d :e]] (->> coll (iterate pop) (take (count coll)) (reverse) (cons []) (mapv vector coll)))
18:58	clojurebot	[[:a []] [:b [:a]] [:c [:a :b]] [:d [:a :b :c]] [:e [:a :b :c :d]]]
18:59	michaniskin__	excellent
19:03	eblood	justin_smith: thanks.. that worked
19:28	slester	I'm struggling a bit with laying out my code; it seems bad to have to (declare) a bunch of functions at the beginning :(
19:28	gfredericks	TimMc: I missed your comments earlier
19:28	gfredericks	I do appreciate the "no two elements are unequal" formulation
19:29	gfredericks	but regarding your other one about removing elements, you have the flipside of "adding an element can always turn true to false", which wouldn't be true for (=)
19:29	slester	My code if someone is generous enough to given comments: https://github.com/slester/amiss/blob/master/src/amiss/core.clj -- always appreciated! I'll keep doing some searching to see what the Internet says
19:30	justin_smith	slester: I think the logic of your domain means that inherently each operation needs to conditionally invoke others
19:31	justin_smith	slester: you could use a big letfn or something, but it is cleaner to just declare them and let them mutually conditionally call one another
19:35	{blake}	Is there a "mapmerge" equivalent of "mapcat"?
19:36	justin_smith	{blake}: isn't that just (partial reduce merge) ?
19:36	justin_smith	oh no, you are doing some function to each element before merging
19:36	sdegutis	{blake}: How about (->> coll (map f) (apply merge))
19:36	justin_smith	so it's (apply merge (map f coll))
19:37	sdegutis	justin_smith: Oh reduce, clever.
19:37	sdegutis	I like how (partial) is implicit in Haskell and (comp) is just .
19:37	{blake}	justin_smith, sdegutis: Right. I was just looking at mapcat and it's (apply concat (apply map f colls))) so I figured there might be one for merge.
19:37	sdegutis	,(source mapcat)
19:37	clojurebot	Source not found\n
19:38	sdegutis	Are you drunk clojurebot?
19:38	sdegutis	##(source mapcat)
19:38	lazybot	java.lang.RuntimeException: Unable to resolve symbol: source in this context
19:38	sdegutis	Oh.
19:38	sdegutis	,(clojure.repl/source mapcat)
19:38	clojurebot	Source not found\n
19:38	sdegutis	##(clojure.repl/source mapcat)
19:38	lazybot	⇒ Source not found nil
19:38	sdegutis	FINE, bots.
19:39	iamjarvo	is there a way for lein repl to load all the files in /src? ive been having to (load-file "file_path")
19:39	justin_smith	iamjarvo: you can specify :main in your project.clj
19:40	justin_smith	iamjarvo: https://github.com/technomancy/leiningen/blob/master/sample.project.clj#L196
19:41	amalloy	~def mapcat
19:42	iamjarvo	justin_smith but thats one namespace, i guess the main namespace should require all the dependencies
19:45	iamjarvo	i was sort of hoping to load the repl and require a namespace or use a namespace as needed
20:31	hefesto	How do you concatenate two strings?
20:32	hefesto	something like: (+ "string 1" "string 2")
20:32	hefesto	clojure.string doesnt seem to have a function that does it.
20:33	gfredericks	,(str "string 1" "string 2")
20:33	clojurebot	"string 1string 2"
20:34	hefesto	thank you!
20:34	hefesto	:)
21:10	TimMc	gfredericks: Interesting point about adding elements!
21:13	gfredericks	do any lisps evaluate (=)?
21:20	justin_smith	guile> (=) => #t
21:20	justin_smith	first one I tried
21:21	justin_smith	common lisps don't like it
21:33	gfredericks	I don't imagine the question even applies to any other popular languages
21:34	justin_smith	lush demands exactly two arguments
21:34	TimMc	=.apply([])
21:41	kclawl	what makes clojure more functional than python?
21:42	gfredericks	immutable data structures?
21:42	kclawl	anything else?
21:42	justin_smith	kclawl: the core functions and data structures make side effects rare
21:43	justin_smith	kclawl: in python you can code functionally if you have a lot of self discipline and keep track of the gotchas (hidden or unexpected mutation) - in clojure it's the default, the easy way to code
21:46	kclawl	yeah I see
22:18	TimMc	You can opt out of it, of course, but it has to be somewhat explicit.
22:20	gfredericks	it's not just a language attribute it's a community/ecosystem thing too
22:27	sg2002	kclawl: The semantics itself is more functional too. Python expressions are imperative.
22:36	kclawl	sg2002 hmm, what makes python expressions imperative?
22:43	gfredericks	do all python expressions return something?
22:47	sg2002	kclawl: Lisp expressions are functional because they always return a value. Python expressions generally don't return a value. if a==b{ x} else{ y} in an imperative language like python means "DO x when a==b or DO y". In a lisp similar statement means "return value from doing x when a==b or value from doing y".
22:52	kclawl	ah ok.. python is if expression too, but it is kind of ugly and backwards
22:52	kclawl	10 if True else 20
22:59	sg2002	kclawl: Python expressions are not backwards or ugly, but from the point of functional programming those expressions are a layer of accidential complexity.
23:01	kclawl	10 if True else 20 is backward and ugly
23:01	kclawl	first a then value, then boolean check, then else
23:29	amalloy	gfredericks: i think expressions that don't return something get called statements