#clojure – 2008-10-09

2008-10-09

00:25	abrooks	Chimp's Clojure support is nice: http://kotka.de/projects/chimp.html
00:25	Chouser	yeah, pretty clever use of screen
00:27	abrooks	Chouser: It's more polished than the like-slime-for-vim plugin.
00:27	abrooks	I was playing with that a bit but this is a much better starting point.
00:27	Chouser	oh, I hadn't tried that.
00:28	abrooks	Chouser: Are you using Chimp?
00:28	Chouser	have used. I suppose I should try to set up some scripts or keybinding to make launching it easy.
00:28	abrooks	I let localmapleader=","
00:29	abrooks	,et is pretty easy to type
03:14	schlarf	when you guys use slime, is that clojure-mode for emacs or is it the normal slime?
03:14	schlarf	or is it slime+enclojure-stuff?
04:27	schlarf	man desctruturing is nice, the more i use clojure the more it seems like the pragmatic programmers hoice out of functional languages. innovative and fresh, still very neat and practical
04:32	hoeck	schlarf: yeah, at the beginning i was very sceptical about the functional and immutable stuff, but somehow, lazy sequences are way better than generators and loops
04:57	schlarf	Hmm I now have def-class, def-method, method-lookup, super for my object-system. 1. are those names ok with you clojurers? 2. what object-system do you prefer, common lisp, java , python etc?
04:57	schlarf	method-lookup is internal btw
05:03	tWip	schlarf: I prefer none
05:03	tWip	Most times using functional programming, I don't need an object system in the traditional sense.
05:07	schlarf	ok but im implementing one anyway just to learn(lisp/clojure and how to create an object-system)
05:07	schlarf	so might as well try to do something people might find useful
05:12	H4ns	schlarf: i'd suggest that you just go ahead and write one that suits you
05:23	schlarf	yes
06:30	schlarf	cant i do : for key, value in zip(Map.keys, Map.values): do-something
06:30	schlarf	like in python
06:30	schlarf	i find no zip-function
06:30	schlarf	i could ofc write one
06:31	schlarf	zipmap
06:32	schlarf	lol that was the pooopiste
06:32	schlarf	opposite
06:32	H4ns	(find-doc "zip") may help
09:04	schlarf	how can i set intendation to 4 chars instead of 2? and always 4 chars...
09:04	schlarf	im using clojure-mode for emacs
09:06	schlarf	is lisp-paste-clojure not working?
09:18	schlarf	rhickey: do you work on clojure as a part of your job or it is something you do in your free-time?
09:18	rhickey	schlarf: that question presumes traditional notions of 'job' and 'free time' :)
09:19	schlarf	lol
09:30	tWip	weird.. entering 08 or 09 results in ReaderError with number format exception
09:31	tWip	others like 02 evaluate to the expected number
09:31	rhickey	tWip: leading 0 means octal - 011 -> 9
09:32	tWip	ok, I thought that I must be missing something
09:32	rhickey	8 and 9 are not valid octal digits
09:32	tWip	but that is a logical explanation, thanks
09:41	schlarf	how do i import? if i have a file object-system and i want it to be imported into my user.clj?
09:42	schlarf	and how are the lookup-rules? like does it look in the currenct directory only?
09:44	rhickey	schlarf: Clojure uses the Java classpath system
09:53	schlarf	rhickey: ok i dont know how that works. if i have a file objectsystem.clj in the same dir as user.clj, how would i write? (import ObjectSystem.clj)
09:53	schlarf	doesnt work
09:54	schlarf	nor does (.import ...)
09:54	Chouser	schlarf: the "right" way to do a lib is to put a file in a package and namespace subdir
09:54	Chouser	like: schlarf/objectsystem/objectsystem.clj
09:54	schlarf	ok
09:55	Chouser	then you make sure that "schlarf"'s parent dir is in your classpath
09:56	Chouser	like: java -cp clojure.jar:/my/dir (where shlarf is actually /my/dir/schlarf)
09:56	Chouser	once that's set up, users can just say (ns foo (:require [schlarf/objectsystem :as sos])) and start calling your functions like: (sos/bar ...)
10:07	schlarf	does it really have to be that complicated?
10:07	Chouser	nope, though it's usually worth it in the long run.
10:07	schlarf	or wait maybe it osnt
10:07	Chouser	you could just say (load-file "objectsystem.clj")
10:08	schlarf	i cant find documenation on package and requie
10:08	Chouser	(doc ns) (doc require)
10:39	cooldude127	hey all
10:39	cooldude127	anyone using jambi with clojure?
10:41	abrooks	cooldude127: I think Chouser did a little once.
10:42	cooldude127	i just dled it, and i'm not sure where to put everything so that it all gets loaded by default. i'm using to clojure with slime, so i'm not really sure how to mess with my classpath
10:42	cooldude127	s/using to/using
10:43	abrooks	cooldude127: Do you have a jambi jar?
10:43	cooldude127	yeah
10:43	cooldude127	it needs two i think, one generic and one for the platform
10:43	cooldude127	i have them both, just not sure what to do
10:45	abrooks	I assume this is on Linux? I'd try exporting the full path to the generic jambi jar in the CLASSPATH environment variable before starting slime.
10:46	cooldude127	mac os x actually
10:47	H4ns	cooldude127: i found it easiest to set up the classpath in the 'clojure' shell script that i use both to start clojure in slime and on the command line.
10:47	cooldude127	oh
10:47	H4ns	cooldude127: i find that easier to work with than messing with the environment.
10:47	cooldude127	i guess so, but it means i need to go back and look and swank-clojure and reconfigure it
10:48	cooldude127	right now i'm just loading the clojure jar
10:48	H4ns	cooldude127: it is a one-line change.
10:48	H4ns	(well, except for the shell script thing) :)
10:48	cooldude127	yeah, what is the one line change?
10:49	cooldude127	the readme for swank-clojure isn't too clear
10:49	cooldude127	wait is it just swank-clojure-binary?
10:49	H4ns	right
10:49	cooldude127	instaed of swank-clojure-jar-path
10:49	cooldude127	ok
10:49	H4ns	that did it for me. i had to restart emacs to make that work.
10:50	cooldude127	should be enough i would think to reevaluate that, clear out swank-clojure-jar-path, and kill the slime and inferior-lisp buffers
10:50	cooldude127	but now saying all that makes restarting emacs seem much simpler
10:52	cooldude127	what would i put in my shell script? how does it want me to start clojure?
10:52	cooldude127	just a repl?
10:54	H4ns	there is this clojure-contrib shell script that i use
10:54	cooldude127	in the sourceforge project?
10:55	cooldude127	or github?
10:56	H4ns	github
10:57	achim_p	hi! this is not really a clojure question: has anybody successfully used Runtime.exec or ProcessBuilder for remote controlling interactive external processes?
10:58	achim_p	starting processes (like "bash" or "ftp") works fine, i can send them input strings and read the responses, but they won't send me a prompt. this seems to be due to them behaving differently depending on whether started in a terminal (isatty) or a pipe. does abybody know a (hopefully cross-platform) way to evoke terminal-like behaviour of subprocesses?
10:59	schlarf	right now i have (method-lookup method_name instance) but i want (method_name instance) ; to get that id have to change the parser of clojure or do something like ($width rectangle) , having a prefix to all methods? which is basically the same anyway. ($ width rec)
10:59	achim_p	i started working on a simple popen/expect for clojure (http://www.bitbucket.org/achimpassen/clj-popen-expect/src/tip/src/io/popen/popen.clj), but expect isn't that useful without prompts ...
10:59	schlarf	or i could do (instance method)
10:59	schlarf	and somehow have some lookup-dispatch-table
10:59	schlarf	somethinglol
11:00	schlarf	(instance $ method)
11:00	schlarf	$ being a macro
11:01	schlarf	can i have backtracking macros? how do i get a form like: (rec $ width) ?
11:01	schlarf	if $ is a macro it can take width as a param, but how does it get rec?
11:01	schlarf	i guess ($ rec width is more lisp-ish)
11:03	schlarf	(load-file "file.clj") only works in currecnt directory?
11:04	schlarf	i cant do (load-file "current/next-dir/file.clj") ?
11:05	Chouser	to invoke a macro, its name has to be at the front of a list (macro-name arg1 arg2)
11:05	schlarf	yeah works
11:13	schlarf	what is a good symbol for using a method on object? ($ rec width) stinks
11:13	schlarf	so does >>
11:14	schlarf	(! rec width)
11:14	schlarf	taken
11:14	schlarf	(\ rec width)
11:15	schlarf	(\| rec 'width)
11:21	tWip	how about? (rec :width)
11:21	tWip	if objects are functions of their messages
11:22	Chouser	or (width rec) like multimethods already allow
11:31	peter_12	tWip: ++
11:39	schlarf	chouser: you prefer multimethods?
11:41	Chouser	schlarf: to what?
11:49	schlarf	uhm, message-passing?
11:49	schlarf	single disptach?
11:50	Chouser	As far as I understand, clojure's multimethods are superset of regualr single-disptach object systems.
11:51	schlarf	but lets seee, if i do (rec :width) then how would i parse that ? without change clojure interpreter? when it sees rec it will see a reference, how would it know what to do with it? it would have to be ordered to look at the next arguments, but how?
11:51	Chouser	It's pretty easy to define a method that dispatches on the type of the first arg.
11:51	schlarf	yes (width rec) is easy, but (red width)?
11:52	schlarf	red=rec
11:52	tWip	if your objects are functions
11:53	Chouser	or if they are objects that implement IFn
11:53	schlarf	right now they are references
11:54	Chouser	they could be functions that are closed around a reference
11:55	schlarf	could you link to something that describes that? now i have the problem that i cant bind a method to a reference directly but i bind a method to a def that is a ref
11:55	cooldude127	anybody want to play a game of spot the error?
11:56	cooldude127	ava -Dpid=5760 -XstartOnFirstThread -cp .:/Users/mattmoriarity/usr/src/qtjambi-mac/*.jar:/Users/mattmoriarity/usr/src/clojure/clojure.jar clojure.lang.Repl
11:56	cooldude127	s/ava/java
11:56	cooldude127	brings up a repl but the jambi classes are non existent
11:57	Chouser	can you use *.jar in the classpath? I didn't know that.
11:57	cooldude127	i wondered, so i just tried it with the clojure jar
11:57	cooldude127	totally works
11:57	cooldude127	java -cp ~/usr/src/clojure/*.jar clojure.lang.Repl
11:57	cooldude127	brings up a repl
11:58	Chouser	ah, not quite the same thing. try .:/whatever/usr/src/clojure/*.jar
11:58	cooldude127	fcuk
11:58	cooldude127	*fuck
11:59	rhickey	try leaving off the .jar, just use *
11:59	cooldude127	zsh barfed on it when there were multiple components in the -cp arg
12:00	cooldude127	* only works when you have a single cp component
12:01	cooldude127	is my conclusion
12:01	cooldude127	adding ".:" to the front killed it
12:02	cooldude127	i guess it's the shell that is affecting that
12:02	Chouser	cooldude127: it depends on whether it's your shell or java that's interpreting the * -- in your first clojure/*.jar test, zsh was expanding that before handing to java
12:02	rhickey	try putting '*'
12:02	rhickey	no .jar
12:03	rhickey	http://blogs.sun.com/mr/entry/class_path_wildcards_in_mustang
12:03	cooldude127	zsh cries with or without the .jar
12:03	cooldude127	which java is mustang?
12:03	cooldude127	is that 6?
12:03	cooldude127	cuz this is 5
12:04	Chouser	cooldude127: try with qoutes: java -cp ".:/foo/:/bar/" ...
12:04	cooldude127	k
12:04	cooldude127	i'm not sure what happened. it killed my terminal tab
12:04	cooldude127	wtf
12:04	cooldude127	it keeps doing that!
12:04	cooldude127	ahhh
12:05	cooldude127	still doesn't work. i don't think java 5 does wildcards in the cp
12:06	cooldude127	looks like i just have to list out the jars, cuz when i do that, everything is happy :)
12:11	cooldude127	ok my clojure script is working and loading the jambi classes
12:12	cooldude127	swing does have something going for it: the easy of setup (aka no setup)
12:17	lisppaste8	Chouser pasted "closing over a ref, for schlarf" at http://paste.lisp.org/display/68199
12:20	Chouser	where "sure" is "use" :-P
12:20	Chouser	lunch, bbl.
12:29	cooldude127	ahh dang it. stupid jambi
12:29	cooldude127	i can get the simple hello world example to work in the terminal
12:30	cooldude127	but if try to do it from slime, i have some problems
12:33	abrooks	cooldude127: Is slime somehow not passing the CLASSPATH environment variable? Can you just add the jambi path to the java -cp commandline argument?
12:33	cooldude127	it's not that the jambi classes aren't loading
12:33	cooldude127	when i try to make an app
12:33	abrooks	cooldude127: Oh.
12:33	cooldude127	slime doesn't return to the repl
12:33	cooldude127	i enter my expression and it just sits there
12:34	abrooks	Does the jambi application window come up? It's probably blocking on the application. You could try sending the application call off in a thread.
12:35	cooldude127	the window does not come up is the problem
12:35	cooldude127	how would i do it in another thread?
12:46	cooldude127	alright new question:
12:46	cooldude127	trying to translate this java: quit.clicked.connect(QApplication.instance(), "quit()");
12:47	cooldude127	came up with this clojure: (.. b clicked (connect (QApplication/instance) "quit()"))
12:47	cooldude127	but i get this error: java.lang.IllegalArgumentException: More than one matching method found: instance
12:50	cmvkk	If I have a multimethod and I want it to dispatch on two values, but to default out on one of them, can I do that?
12:50	cmvkk	for example, if i want to dispatch on [:foo :bar], but if that doesn't exist, to default to [:foo :default]
12:51	cmvkk	or something like that
12:53	digash	blist
12:53	rhickey	cmvkk: you could (derive :bar :default)
12:55	cmvkk	aha, that would work, thanks.
12:57	cooldude127	how can (QApplication/instance) have multiple matching methods?
12:58	rhickey	cooldude127: I don't see how, are there online JavaDocs you can point me to? Does it derive from something generic?
12:59	cooldude127	here are the javadocs
12:59	cooldude127	http://doc.trolltech.com/qtjambi-4.4/html/index.html
13:00	cooldude127	com.trolltech.qt.gui.QApplication.instance()
13:00	cooldude127	i would have linked straight to that but i believe frames would not work with that
13:01	cooldude127	rhickey: i saw another person on gmane with this problem but they added a type annotation to fix it. and this case doesn't really have anything to annotate
13:03	cooldude127	found a temporary fix: the superclass QCoreApplication has an instance() method that works fine and returns the right thing
13:04	cooldude127	but i still don't see how this was messed up in the first place
13:08	cooldude127	is there a way to import every class in a package?
13:09	Chouser	cooldude127: no, there is not. This is intentional.
13:09	cooldude127	ah man
13:10	cooldude127	cuz it would really make the repl more convenient
13:10	Chouser	but you don't have to repeat the package name. Just (import '(foo.bar Baz Bang Boom))
13:12	Pupeno	Hello.
13:12	cooldude127	yeah, but i'm not always aware when i do that of all the classes from the package that i want
13:13	cooldude127	so i have to keep going back
13:13	Chouser	Pupeno: hi
13:13	cooldude127	bring it on the vacation :)
13:14	arohner	is the slime checkout working for anyone else? I'm getting connection refused
13:14	rhickey	cooldude127: it must have to do with the same-sig static method in the base class
13:14	cooldude127	rhickey: it's debating between the one in QCoreApplication and QApplication?
13:15	cooldude127	is that a clojure problem or jvm problem?
13:15	rhickey	cooldude127: shouldn't be, but is
13:17	cooldude127	ahh
13:17	cooldude127	that is not cool
13:18	rhickey	anyone know of an instance of that in the JDK libs - derived class and superclass with same-sig static method?
13:19	cooldude127	i wasn't even sure you could do that
13:23	cooldude127	oh snap time to learn how to make java objects in clojure :/
13:24	aquanaut	Hello
13:24	Chouser	aquanaut: hi
13:24	aquanaut	How does one open a file for reading or writing?
13:24	Chouser	cooldude127: "proxy" isn't too unpleasant
13:24	cooldude127	nvm no it's not
13:25	cooldude127	yeah i wasn't all that scared it looks simple
13:25	cooldude127	turns out i don't need to do that anyway
13:25	cooldude127	all these stupid qt examples do it put a bunch of initializer code in the constructors. they don't really override anything
13:25	cooldude127	i can do all this outside a class completely
13:25	aquanaut	Also, any ideas why clojure doesn't dispatch on singletons?
13:25	Chouser	aquanaut: (doc slurp) for files
13:26	Chouser	aquanaut: what do you mean, dispatch on singletons? are you talking about static methods?
13:27	aquanaut	slurp brings the reads the file into a string, I need to keep the file open.
13:27	cooldude127	aquanaut: with-open
13:27	cooldude127	pass in a java.io.FileReader
13:28	cooldude127	basically just makes sure you don't forget to call close on your stuff
13:28	Chouser	aquanaut: in that case I highly recommend clojure.contrib.duck-streams, otherwise you have to do the same dance as in Java with IOStreams, Readers, and whathot
13:28	cooldude127	otherwise you're interacting with the java io stuff
13:28	Chouser	er, whatnot
13:28	Chouser	cooldude127: with-open doesn't actually open anything :-)
13:28	cooldude127	i know
13:28	Chouser	it's more of a "with close" actually.
13:28	Chouser	oh, ok.
13:28	cooldude127	lol yeah
13:31	cooldude127	oh duck streams looks nifty
13:31	cooldude127	i would say use that along with with-open
13:31	cooldude127	despite the confusing name
13:32	aquanaut	(defn fact [0] "off" [1] "on" [x] "unknown")
13:32	cooldude127	pattern matching is only on arity, not actual values
13:33	rhickey	that's not pattern matching, just arity overloading
13:33	cooldude127	yeah, that makes more sense
13:33	aquanaut	why no pattern matching on values?
13:34	rhickey	aquanaut: there's no pattern matching
13:34	cooldude127	EVER
13:35	rhickey	cooldude127: I didn't say that, but it's important to note that function args are just that, args, not patterns/conditionals
13:35	cooldude127	yeah i know
13:35	cooldude127	it confused me at first tho too. idk why i came to expect this
13:35	aquanaut	I understand the language doesn't support pattern matching, my question is what is the rational behind it.
13:36	rhickey	pattern matching is inextensible
13:36	cooldude127	so use multimethods instead?
13:36	rhickey	vs multimethods, say
13:36	cooldude127	ah
13:36	cooldude127	pattern matching is more succinct i would think in small cases like his
13:38	rhickey	aquanaut: (defn fact [x] ({0 "off" 1 "on"} x "unknown"))
13:38	cooldude127	when the differences in behavior are big or extensibility is very important, multimethods all the way. but it's kind of overkill for something like a factorial
13:38	cooldude127	OH
13:38	cooldude127	i like that
13:38	cooldude127	i wish you would have sent that before i typed all that bullshit
13:38	cooldude127	saved me some keystrokes
13:39	aquanaut	rhickey: I am not sure I understand how this works.
13:39	cooldude127	maps are functions that will lookup by key
13:40	cooldude127	the last arg is what to return if the key isn't in the map
13:41	aquanaut	But this will work only for methods with only one argument
13:41	cooldude127	yeahhhh
13:41	cooldude127	multimethods :)
13:41	aquanaut	What is the multimethod solution
13:42	rhickey	arity dispatch is direct - no conditionals, no counting, so any other conditionals must be done at the next level, in the body
13:44	lisppaste8	cooldude127 pasted "multimethods" at http://paste.lisp.org/display/68204
13:44	cooldude127	rhickey might be able to point out a better way but that was my multimethod solution
13:45	cooldude127	seems a tad verbose, but maybe a macro could fix it up?
13:45	rhickey	there's no reason for multmethods here, we were talking generally about alternatives to pattern matching. In the smallest cases it could be maps or cond
13:46	cooldude127	yeah, but i blew the stack when i tried to use maps
13:46	cooldude127	not sure why
13:46	cooldude127	(defn fact [x] ({0 1 1 1} x (* x (fact (dec x)))))
13:46	rhickey	cooldude127: you read fact as factorial, but that wasn't the function
13:46	cooldude127	i know
13:47	cooldude127	i went off in my own direction lol
13:47	aquanaut	cooldude127: you blew the stack beacuse of the lack tail calls
13:48	cooldude127	except for i only should have made 5 function calss
13:48	cooldude127	*calls
13:48	cooldude127	5ish
13:49	rhickey	that's not tail recursive anyway, call to fact is not in tail position
13:50	aquanaut	Thats right. It is just recursive
13:50	cooldude127	yeah. it shouldn't have blown the stack anyway with a (fact 5 call)
13:50	cooldude127	(fact 5) call
13:50	cooldude127	that is
13:51	johnwayn`	probably because the default value is going to be calculated first
13:51	cooldude127	the multimethod solution is the same code inside and it works fine
13:51	aquanaut	It blows it even for (fact 1)
13:51	cooldude127	OH
13:51	cooldude127	johnwayn` is brilliant
13:51	johnwayner	hardly
13:51	cooldude127	but you did figure this one out
13:51	johnwayner	I get one point :)
13:52	cooldude127	so the maps solution doesn't work out with a recursive function
13:52	rhickey	cooldude127: maps doesn't work with any function, just a mapping of values to values like the original question
13:53	cooldude127	yeah
13:53	cooldude127	i see that now
13:53	cooldude127	why can't everything be lazy?
13:53	cooldude127	:)
13:54	gnuvince	cooldude127: it is in Haskell (and it causes its share of problems too ;))
13:54	cooldude127	yeah i've done a little haskell. like the laziness, but the purity just makes things difficult sometimes
13:54	cooldude127	and yes the laziness can be annoying too
13:54	cooldude127	just less often
14:00	lisppaste8	johnwayner pasted "map factorial for cooldude" at http://paste.lisp.org/display/68206
14:01	johnwayner	:)
14:04	gnuvince	Why so complicated?
14:04	lisppaste8	cooldude127 annotated #68206 with "slightly better" at http://paste.lisp.org/display/68206#1
14:05	johnwayner	just proving I'm not "brilliant"...
14:05	cooldude127	lol
14:05	gnuvince	Any reason you're using a hash?
14:05	cooldude127	because we can
14:05	cooldude127	not the best way by any means
14:06	wwmorgan	why are there two base cases?
14:06	johnwayner	yeah...it's kinda a joke
14:06	gnuvince	How about: (defn fact [n] (apply * (range 1 (+ 1 n)))) ?
14:06	gnuvince	k
14:06	cooldude127	i would use reduce over apply
14:07	cooldude127	idk about clojure but other lisps have a limit on the number of args you can pass to a function
14:08	rhickey	(apply + (range 1000000))
14:08	cooldude127	ok i guess it's not a problem for clojure :)
14:08	rhickey	indefinite amount via apply
14:09	cooldude127	apply and reduce take about the same time
14:10	cooldude127	space-wise, who knows
15:07	lisppaste8	schlarf pasted "list and eval" at http://paste.lisp.org/display/68211
15:08	schlarf	^^ can someone explain that. how to create a list and have ref in it
15:08	schlarf	do i need a macro?
15:10	schlarf	hmm i could pass as parameters to def-method perhaps
15:36	Chouser	If you want the value of i to change over time, it should be a ref.
15:36	Chouser	I demonstrated that in my earlier paste, did you see it?
15:38	schlarf	it is a ref
15:38	schlarf	i is a ref
15:39	schlarf	if i list the value of ref is listed and the function performed, thus replacing witht he value of the function
15:39	schlarf	if i quote then it is the char /symbol i not the value of i
15:42	schlarf	i write like shit on irc lol
15:43	Chouser	from you paste, I can't really tell what you're doing. Can you provide a short but complete example?
15:43	Chouser	by complete I mean: not referring to things without defining them
15:46	lisppaste8	schlarf pasted "oo-system" at http://paste.lisp.org/display/68214
15:46	schlarf	^^ all the code, some is duplicated, im still refactoring and rewriting and far from done
15:47	danlarkin	schlarf: neat
15:51	schlarf	dan: thanks, i will make it more complete and perhaps have some meta-class-system to easily define your own ==-system
15:51	schlarf	OO-system
15:52	solkis	Being new to Emacs and clojure, can anyone explain to me the difference between simple inferior-lisp mode and slime/swank? Initially I setup the former and now I have the latter but I'm not sure what other benefits the slime integration brings.
15:52	schlarf	slime = Superior Lisp Interactione Mode for Emacs
15:52	schlarf	name should say all
15:54	solkis	schlarf: saw that... that's why I loaded it :-) now I want to know what makes it superior
15:56	solkis	I see the feature highlights on the slime page (which I'm not enough of a lisp/clojure hacker to grok completely) but I didn't know if there was some killer feature in terms of clojure
15:56	shoover	clojure-mode gives the basic syntax highlighting and code navigation features. slime adds more features like macroexpansion, tab completion in the the REPL, stack traces from the REPL. Do you have a slime menu at the top? All those features are beyond what clojure-mode has.
15:57	shoover	(but some of the features in the menus aren't implemented yet for Clojure)
15:59	solkis	shoover: yes, I do have the menu... I'll check it out through that. thx
16:52	Pupeno	Do I have to define a function before using it in a file? like in C (without headers)?
16:53	drewr	It has to be defined before using it, yes.
16:53	drewr	You can do it in a file or at the REPL.
16:54	Pupeno	That's nasty :(
16:55	drewr	?
16:55	Pupeno	I tend to have util-functions at the bottom of the files.
16:56	drewr	Every time you start a new JVM, it has to be loaded with code you want to have access to.
16:56	Pupeno	Actually, my files tend to look like:
16:56	Pupeno	(def a [] b)
16:56	Pupeno	(def b [] c)
16:56	Pupeno	I mean,
16:56	Pupeno	(def a [] (b))
16:56	Pupeno	(def b [] (c))
16:57	Pupeno	(def c [] 1)
16:58	schlarf	is there any advantage of single dispatch over multipel dispatch?
16:58	schlarf	just easier to implemetn?
16:58	rhickey	you can pre-def things with (def x), then provide full def later
16:58	walters	schlarf: it maps to the virtual metal
16:59	Pupeno	rhickey: is there a reason why it doesn't just work?
17:00	schlarf	walters:you mean it is more like how a computer works whiole multiple dispatch is the more abstract concept?
17:00	Chouser	Pupeno: names are resovled at compile time, so that runtime performance is better
17:01	rhickey	names that can't be resolved could be bound in current-ns, but errors would be much harder to detect
17:03	Pupeno	So, what do you do? Have a C-style header, defing everything, or have the functions in bottom-up order?
17:03	rhickey	then there is the CL interning/package problem. You use foo, intending some-ns/foo, but hadn't referenced it. This has the side effect of interning your-ns/foo, at runtime you get an error, you try to fix it by making the refer but now some-ns/foo is in conflict with your-ns/foo
17:05	rhickey	Pupeno: personal preference
17:05	cemerick	Pupeno: you only need to def the things you refer to in other code before fully defining them. I think I have pre-def'ed 10 fns over the past 4 months
17:06	Pupeno	cemerick: then you are using bottom-up order, I pressume.
17:06	rhickey	but yes, if you wanted a true top-down file you'd have more defs
17:07	cemerick	Pupeno: Not consciously. I also put a lot of effort into moving generally-useful fns into other namespaces.
17:07	rhickey	I think the answer is some sort of intern-tracking, checking that actual defs have been made by end-of-file, but that is kind of icky in being file-based, and I haven't had time to refine the idea
17:08	cemerick	It's a really minor thing, IMO.
17:08	rhickey	It was raised early on, but I don't get many complaints
17:11	Pupeno	I understand why there may not be a straightforward solution, but I really thought I escaped that problem when I stopped conding in C years ago. Personally, for me it's not a minor thing, but I can understand it is for others.
17:18	lisppaste8	arohner pasted "stupid java print stack trace" at http://paste.lisp.org/display/68217
17:19	arohner	notice the "and 68 more lines" at the bottom of the stack trace? That's why we need to extend .printStackTrace()
17:19	arohner	rhickey: would you be accept a patch that does that?
17:19	rhickey	what do you mean by extend?
17:21	arohner	create a subclass of java.lang.Exception that has a working printStackTrace()
17:21	rhickey	I don't think so
17:22	arohner	well, my desired goal is not have java print "and 68 more lines"
17:22	rhickey	can't you just write a better stand-alone pst function that works with any exception?
17:23	arohner	oh, yeah, looks like you can using exception.getStackTrace()
17:25	ggbbgg	what does trailing '#' mean on symbols in defmacros ?
17:26	rhickey	ggbbgg: that's an auto-gensym - guaranteed to be a unique name, and every x# in the same ` expression is the same name
17:27	ggbbgg	thanks rich.
17:30	arohner	is it a bug that (macroexpand '(foo..)) generates a compiler exception?
17:31	arohner	I have a macro that is doing something broken, so I did (macroexpand '(foo...)) and I only get the exception
17:31	rhickey	what is ... ?
17:32	arohner	(macroexpand '(mk-validator validate-not-blank not-blank-pred "must not be blank"))
17:32	rhickey	works here
17:32	arohner	right, but mk-validator is my broken macro
17:33	rhickey	and the exception doesn't help?
17:34	arohner	I was surprised that I got a compiler exception instead of source code
17:34	rhickey	your macro is being called by the compiler, it is failing
17:35	rhickey	the expander itself, not the expansion
17:40	arohner	ok, let me approach this a different way. can you create a defmacro that returns a defn?
17:40	rhickey	arohner: sure
17:42	Pupeno	lisppaste8: url
17:42	lisppaste8	To use the lisppaste bot, visit http://paste.lisp.org/new/clojure and enter your paste.
17:43	lisppaste8	Pupeno pasted "defs" at http://paste.lisp.org/display/68220
17:44	Pupeno	I wrote a macro to define a bunch of names, (def a) (def b) (def c), like that. Can it be improved?
17:45	rhickey	Pupeno: looks ok, you might want to call it declare
17:46	rhickey	good candidate for the standard lib
17:46	Pupeno	rhickey: thanks.
17:47	rhickey	macros to the rescue
17:47	Pupeno	rhickey: I could try to include it into Clojure by myself and send you the patch, write tests if needed, documentation, whatever. It's probably trivial for you, but I'd like to get my hands dirty in Clojure itself.
17:47	rhickey	I'll add it
17:48	Pupeno	Ok.
18:01	lisppaste8	arohner pasted "no error or stack trace" at http://paste.lisp.org/display/68221
18:01	arohner	this looks to be the most isolated version of the problem I was having
18:01	arohner	though this doesn't have a stack trace, and I'm not sure why
18:06	danlarkin	macroexpand-1 gives (clojure/defn clojure.name__482@c610af [user/a] (clojure/println user/a))
18:08	danlarkin	I think you have a typo in that macro
18:08	arohner	I do, that was the point
18:08	danlarkin	oh
18:08	danlarkin	d'oh :o
18:11	danlarkin	is it something about using name like that?
18:11	arohner	name is an already existing function
18:11	arohner	I should have used ~fn-name instead of ~name, but I made a mistake
18:11	arohner	the point of the paste was that the error was not very useful
18:12	danlarkin	arohner: yeah you were way ahead of me
18:12	danlarkin	I'm caught up now though!
18:29	lisppaste8	johnwayner annotated #68220 with "more DRY" at http://paste.lisp.org/display/68220#1
18:32	johnwayner	Pupeno: Perhaps you can do something like that last annotation to save some typing.
18:35	duck1123	does anyone else have problems using slime with clojure
18:35	duck1123	I'm running up to date on everything
18:36	duck1123	I'm still getting "java.lang.Exception: Unable to resolve symbol: progn in this context (NO_SOURCE_FILE:1)"
18:36	johnwayner	are you using the clojure swank?
18:36	duck1123	yes
18:37	shoover	Somehow it's sending Common Lisp code to the clojure swank. Do you have (require 'swank-clojure-autoload) before (require 'slime)?
18:37	johnwayner	perhaps a paste of the appropriate parts of your emacs configuration would shed light?
18:38	duck1123	it looks like slime-init-command is generating the code
18:39	duck1123	so swank-clojure has to be required first?
18:39	Pupeno	johnwayner: thanks for the annotation. I absolutely agree it's more DRY, or actually DRY, but I haven't done it for two reasons: 1- I'm not sure I like how the code looks when using that macro 2- It goes way beyond my macro-skills. I wonder if Emacs can be configured to not indent after a certain special keyword in a form...
18:39	lisppaste8	johnwayner pasted "slime emacs config" at http://paste.lisp.org/display/68224
18:39	shoover	duck1123: Yes, that autoload sets up some things so that the generic slime code knows which swank code to use
18:41	johnwayner	Pupeno: hmmm you'd probably have to tweak clojure-mode.
18:42	lisppaste8	shoover annotated #68224 with "there's always another way" at http://paste.lisp.org/display/68224#1
18:49	duck1123	thanks guys. I got it working with shoover's code
18:49	duck1123	now to put back the rest of my .emacs file
18:55	danlarkin	johnwayner: what does this with-fwd-declare macro do?
18:56	johnwayner	it finds all your defn's and forward declares them so you can use them before you define them.
18:57	johnwayner	Pupeno was looking for way to do top down definitions
18:57	johnwayner	I'm not even suggesting this is the best way to do it. I'm a newb :)
18:58	danlarkin	johnwayner: oh, cool!
18:58	johnwayner	thanks :)
19:15	johnwayner	interesting... why does #(do `(def x)) work, but #(`(def x)) doesn't?
19:17	johnwayner	ooohh.... right. '(def x) isn't a function.
19:34	danlarkin	(#(`(def x))) doesn't work, but ((fn [] `(def x))) does
19:34	danlarkin	I wonder why that is
19:34	johnwayner	yeah... that's what threw me
19:35	Chouser	currently macros are just functions that return a list (of code), and are marked using metadata as macros
19:35	Chouser	oh, nm, you'd not even dealing with macros.
19:35	Chouser	sorry
19:35	johnwayner	but still interesting to knwo
19:37	johnwayner	is there a non-reader way of doing quoted syntax (`)?
19:37	Chouser	ah, the problem with #() is that #(foo) expands to (fn [] (foo))
19:38	Chouser	thus (#(`(def x))) means ((fn [] (`(def x))))
19:38	johnwayner	yes, whatever you put in #() must be IFn
19:39	Chouser	right, and the LazyCons returned by `(def x) is not IFN
19:40	johnwayner	I guess it just seemed that ` was a short-hand for a function
19:41	johnwayner	or I guess I should say IFn
19:42	johnwayner	meh. doesn't matter... since that result would still need to be called as IFn since it heads a list
19:43	johnwayner	dinner time...
21:14	lisppaste8	johnwayner annotated #68220 with "ok, I'm done messing with this now :)" at http://paste.lisp.org/display/68220#2
21:16	rhickey_	I prefer (declare foo bar baz) preceding their use
22:18	Chouser	hmph. How much does performance matter when printing regex patterns?
22:22	rhickey_	Chouser: not much
22:24	aking	I accidently def'd a var in the wrong namespace - is there a way to 'undef' it without having to restart the jvm? THere seems to be no (remove-var) or similar
22:25	rhickey_	aking: (doc ns-unmap)
22:26	aking	rhickey_: cool - thanks. I also tried 'undef'.. was close :)
22:27	rhickey_	ns-unmap works for imports and refers too
22:54	yangsx	does any body use both CL and Clojure with slime at the same time? Only the last one (either clojure or a CL implementation) works on open files
22:55	danlarkin	yangsx: can you clarify?
22:57	yangsx	danlarkin: sure. I run both sbcl and clojure with slime, if clojure is the last one, then all actions on any lisp buffer are sent to clojure, not sbcl
22:57	yangsx	and vice versa
23:00	yangsx	my slime-lisp-implementations contains both sbcl and clojure, and M-- M-x slime sbcl (or clojure) to run any one of them
23:04	danlarkin	Hm
23:09	danlarkin	the same thing happens to me... but that's with two slime clojures
23:09	yangsx	danlarkin: why two slime clojures?
23:13	danlarkin	working on two files at once