2009-09-25
| 00:03 | drhodes | is there anything built in for doing something like (pow 3M (with-precision 20 (/ 1 3M))) |
| 00:08 | slashus2 | no |
| 02:09 | tomoj | anyone know how to have slime setup for both clojure and, say, common lisp? |
| 02:21 | vy | tomoj: Just introduce related slime-lisp-implementation entries. |
| 02:33 | pixelman | I'm looking for but not finding a function similar to ruby's detect or find. which is like filter but just returns the first match. How can I do something like this in clojure, recur? |
| 02:34 | tomoj | pixelman: find-first in clojure.contrib.seq-utils does it |
| 02:37 | pixelman | tomoj: thanks! |
| 02:40 | pixelman | ah, seq utils isn't in my version of clojure contrib |
| 02:41 | tomoj | you sure? |
| 02:41 | tomoj | maybe it's old I guess |
| 02:41 | pixelman | ah no it was there |
| 02:41 | pixelman | just misspelled clojure :) |
| 02:41 | tomoj | anyway this is the definition of find-first: (defn find-first [pred coll] (first (filter pred coll))) |
| 02:41 | vy | pixelman: filter returns a lazy list, so (first (filter f seq)) should do what you're looking for. (I dunnot if there exists something similar to FIND-IF oor FIND-IF-NOT of CL.) |
| 02:41 | tomoj | so.. pretty simple |
| 02:43 | pixelman | didn't find it when I searched because it wasn't included. |
| 02:44 | pixelman | ok by lazy that means not all of the list will be evaluated |
| 02:44 | pixelman | ? |
| 02:44 | pixelman | or that it will be evaluated only when function is called? |
| 02:47 | vy | AFAIK, `first' will force the evaluation of the very first element only. |
| 02:49 | pixelman | ok! |
| 03:06 | vy | pixelman: See clojure.contrib.seq-utils/find-first |
| 03:06 | vy | http://github.com/richhickey/clojure-contrib/blob/master/src/clojure/contrib/seq_utils.clj#L170 |
| 03:07 | pixelman | vy: thx! seems like it will not evaluate unnecessary stuff! |
| 03:23 | LauJensen | Good morning all |
| 04:16 | pixelman | ,(Math/round (+ 23/9 0.0)) |
| 04:16 | clojurebot | 3 |
| 04:17 | pixelman | is there a simpler way to round down a ratio to an integer? |
| 04:19 | crios__ | guten tag! |
| 04:20 | jdz | ,(float 23/9) |
| 04:20 | clojurebot | 2.5555556 |
| 04:20 | LauJensen | ,(int (+ 0.5 (/ 23 9))) |
| 04:20 | clojurebot | 3 |
| 04:24 | LauJensen | ,(int (+ 0.5 23/9)) |
| 04:24 | clojurebot | 3 |
| 04:25 | LauJensen | pixelman: Thats the fastest simplest bestest way to go :) |
| 04:25 | pixelman | :) |
| 04:26 | pixelman | ,(Math/round (float 23/9)) |
| 04:26 | clojurebot | 3 |
| 04:27 | LauJensen | pixelman: I don't think that's faster or better, do you ? |
| 04:28 | pixelman | LauJensen: :) I want it to work for any ratio |
| 04:28 | LauJensen | i5 2ill |
| 04:29 | LauJensen | oops |
| 04:29 | LauJensen | it will |
| 04:29 | LauJensen | ,(int (+ 0.5 3/4)) |
| 04:29 | clojurebot | 1 |
| 04:29 | LauJensen | ,(int (+ 0.5 1/4)) |
| 04:29 | clojurebot | 0 |
| 04:29 | pixelman | LauJensen: I missed your call to (int first |
| 04:30 | pixelman | LauJensen: yeah, it'll work :) |
| 04:30 | LauJensen | it sure will baby :) |
| 04:30 | LauJensen | Somebody from in here taught me that 6 - 8 months ago, saying it was an old C trick |
| 04:32 | pixelman | C is full of stuff like that |
| 04:33 | pixelman | are you from denmark? |
| 04:33 | LauJensen | Yep |
| 04:33 | pixelman | Then you'll probably appreciate the humor of this: http://unix.se/Gubb-C |
| 04:34 | eevar2 | you want to round down? - I'd shoot for Math/floor and let the JVM inline as neccessary |
| 04:34 | LauJensen | haha :) |
| 04:38 | pixelman | there seems to be a round in clojure contrib that works with ratios |
| 04:38 | pixelman | I'll use that I think |
| 04:39 | pixelman | ,(round 2/3) |
| 04:39 | clojurebot | java.lang.Exception: Unable to resolve symbol: round in this context |
| 04:40 | pixelman | ,(clojure.contrib.math/round 2/3) |
| 04:40 | clojurebot | java.lang.ClassNotFoundException: clojure.contrib.math |
| 04:58 | AWizzArd | LauJensen: You do json with compojure? |
| 04:58 | LauJensen | In one yes, case |
| 04:59 | AWizzArd | My client makes a POST request to Compojure, and writes into the request header {"content-type" "application/json"}, and puts into the body a json form. |
| 04:59 | AWizzArd | How can I read a POST body in Compojure? (= the json form) |
| 05:00 | LauJensen | use contribs json reader (read-json (:body request)) |
| 05:04 | AWizzArd | LauJensen: (defroutes awizzard (POST "/echo" (fn [x] (:body x)))) here (:body x) is a #<Input org.mortbay.jetty.HttpParser$Input@c9de16>. Is there a way to extract the json string out of it? |
| 05:06 | LauJensen | No I think that's taking the long route. Could you add a debugger like (POST "/echo" (doseq [l request] (println l)) - I would be surprised if you didn't see the raw JSon in there |
| 05:11 | sfuentes | can someone explain what a lazy sequence means? |
| 05:12 | noidi_ | sfuentes, it's a sequence whose values are generated only when needed |
| 05:12 | noidi_ | that way you can have an "infinite" sequence |
| 05:13 | noidi_ | ,(take 3 (repeat :foo)) |
| 05:13 | clojurebot | (:foo :foo :foo) |
| 05:13 | noidi_ | (repeat :foo) returns a lazy sequence full of :foo |
| 05:13 | noidi_ | ,(doc repeat) |
| 05:13 | clojurebot | "([x] [n x]); Returns a lazy (infinite!, or length n if supplied) sequence of xs." |
| 05:14 | noidi_ | note that lazyness does not necessarily mean that the sequence is infinite |
| 05:15 | sfuentes | i see. |
| 05:15 | AWizzArd | LauJensen: unfortunately the json string really doesn't show up. I tried it this way: (http-agent "http://localhost:8080/echo" :method "POST" :body "{\"echo\" 123}" :headers {"content-type" "application/json"}) |
| 05:15 | sfuentes | ,(repeat :foo) |
| 05:15 | clojurebot | Eval-in-box threw an exception:java.lang.OutOfMemoryError: Java heap space |
| 05:15 | LauJensen | AWizzArd: pmsg |
| 05:16 | sfuentes | ooops |
| 05:16 | sfuentes | did i break that? |
| 05:16 | Chousuke | clojurebot: ping |
| 05:16 | clojurebot | PONG! |
| 05:16 | noidi_ | if you do that, the repl will try to print all of the sequence |
| 05:16 | noidi_ | which means that all of the (infinite) sequence has to be generated :) |
| 05:16 | sfuentes | i am so sorry. |
| 05:17 | Chousuke | sfuentes: don't worry, it doesn't affect clojurebot |
| 05:17 | sfuentes | i thought it would assume a sequence of 1 |
| 05:17 | Chousuke | I suppose it'll just get the OOM exception and then the seq generated so far will get GC'd |
| 05:19 | noidi_ | ,(+ 2 2) |
| 05:19 | noidi_ | ,(doc repeat) |
| 05:19 | clojurebot | 4 |
| 05:19 | noidi_ | hmm, did that really break clojurebot? :D |
| 05:19 | jdz | should not have |
| 05:19 | noidi_ | maybe a bug in the sandbox? |
| 05:19 | clojurebot | "([x] [n x]); Returns a lazy (infinite!, or length n if supplied) sequence of xs." |
| 05:19 | Chousuke | laggy. |
| 05:19 | jdz | clojurebot had to catch up to the infinite sequence :) |
| 05:20 | jdz | you know, it takes time to GC an inifinite sequence |
| 05:20 | jdz | but clojurebot is fast |
| 05:20 | jdz | relatively |
| 05:20 | Chousuke | well, it gets GC'd lazily :) |
| 05:21 | Chousuke | the not-yet-generated items are GC'd only when needed :D |
| 05:26 | sfuentes | you guys are geeks |
| 05:26 | sfuentes | i like that |
| 05:30 | sfuentes | so what's the difference between using ";" versus "(comment)" ? |
| 05:30 | Chousuke | sfuentes: 'comment is actually a macro |
| 05:30 | Chousuke | so this can happen: |
| 05:30 | jdz | the stuff in comment must be valid clojure expressions |
| 05:30 | Chousuke | ,(comment #<error>) |
| 05:30 | clojurebot | Unreadable form |
| 05:31 | Chousuke | ,5 ;#<no error> |
| 05:31 | clojurebot | 5 |
| 05:32 | sfuentes | so why would use ever use (comment ) ? |
| 05:32 | Chousuke | it's handy for commenting out entire expressions |
| 05:32 | clojurebot | for is a loop...in Java |
| 05:32 | jdz | especially if you have expression-aware editor, like emacs |
| 05:33 | Chousuke | or code that could be evaluated manually in a repl for example |
| 05:34 | sfuentes | ok, i see. |
| 05:34 | atome | the other diffence is (comment) evaluates to something |
| 05:35 | atome | ,(nil? (comment blah)) |
| 05:35 | clojurebot | true |
| 05:35 | Chousuke | the definition of comment is simply (defmacro comment [& body]) |
| 05:35 | atome | which tripped me up a few times, eg if you use (comment ) at the end of a function it'll return nil |
| 05:36 | sfuentes | well i'm glad to see that folks in this channel are very helpful. thank you all. |
| 05:37 | LauJensen | np :) |
| 05:37 | LauJensen | (notice how I sneak in to steal the glory) |
| 05:39 | jdz | you can't steal it. stealing presumes ownership ;) |
| 05:39 | Fossi | ... glorypirate |
| 05:41 | LauJensen | jdz: Man it's hard to keep you happy :)( |
| 05:42 | jdz | nah, i just remembered a quote from "V for Vendetta" |
| 05:43 | jdz | i'm overall a very happy person :) |
| 05:52 | sfuentes | defn- means scoped to current file? |
| 05:53 | Chousuke | private to the namespace |
| 05:54 | sfuentes | ok |
| 05:55 | Chousuke | though it's pretty easy to override if someone really wants to. but don't worry about that :) |
| 05:55 | Chousuke | if someone goes and uses your private functions and things break, it's their fault :P |
| 05:56 | sfuentes | let them clean their mess :) |
| 06:13 | ambient | has anyone written games with clojure yet? |
| 06:13 | ambient | actual games, not something like minesweeper :p |
| 06:15 | jdz | your definition of "actual game" is very subjective |
| 06:16 | ambient | event loop, simulation-type engine, realtime |
| 06:17 | ambient | let's say asteroids done with opengl |
| 06:17 | jdz | look for "pong" in mailing list |
| 06:17 | jdz | that fits your description |
| 06:18 | jdz | not the best example of idiomatic clojure code, though |
| 06:19 | ambient | seems that it has been updated for more idiomatic clojure :) |
| 06:19 | ambient | http://jng.imagine27.com/articles/2009-09-12-122605_pong_in_clojure.html |
| 06:19 | ambient | thanks |
| 06:30 | RomanRoe | The clojure api doc says that watcher are experimental. Is this still up-to-date or can I consider them to be stable? |
| 07:13 | yason | How to force symbol capture in defmacro? I'm experimenting with a macro that expands to defmethod call with a fixed set of argument symbols, and I need to introduce those plain symbols in the macroexpansion so that the body can refer to the arguments. |
| 07:13 | yason | By creating the dang (defmethod ...) call as a list, instead of backquote? |
| 07:19 | LauJensen | ambient: I was working on one when I had the time for it, but you can finish it if you like |
| 07:19 | LauJensen | ~sofiaba |
| 07:19 | clojurebot | sofiaba is http://wiki.github.com/Lau-of-DK/sofiaba |
| 07:29 | Chousuke | ,`(foo ~'foo) ; tason |
| 07:29 | clojurebot | (sandbox/foo foo) |
| 07:30 | Chousuke | yason * :P |
| 07:31 | yason | Chousuke: much easier :) |
| 07:32 | yason | Chousuke: I'm still not that familiar with that stuff (namespaces, fully-qualified symbols and just symbols) |
| 07:33 | pixelman | I want to grab and inspect the request object? in compojure. how can I do that? (pprint request) doesn't give any output anywhere for me |
| 07:34 | pixelman | hm maybe I just can print it to a page, but it would be nice to get it on the log, or in the repl |
| 07:35 | Chousuke | yason: fully-qualified symbols are just symbols too. it's just that neither let nor fn allow them so you can't accidentally capture names. |
| 07:37 | yason | Chousuke: Yeah, I figured out a bit of that each time I used syntax quote for creating a template of something |
| 07:38 | Chousuke | capturing names is rarely needed though. |
| 07:38 | yason | Chousuke: then I got lots of errors because all my symbols had turned into user/mysymbol and I tried to de-qualify them for later processing :) |
| 07:38 | Chousuke | most of the time it's better to just take the names you want to bind as parameters |
| 07:41 | yason | Chousuke: that would work but would cause lots of duplication on the user side :) |
| 07:44 | yason | Chousuke: anyway, thanks for ~' -- it really makes sense now that I thought about it |
| 07:50 | crios__ | Could I ask a bit challenging question? |
| 07:50 | crios__ | What are the application domains for wich Clojure can hope to become a mainstream language, in your opinion? |
| 07:50 | LauJensen | For those interesting in rendering chaotic functions in 80 lines of code: http://www.dzone.com/links/chaos_theory_vs_clojure.html |
| 07:50 | LauJensen | interested :) |
| 07:51 | Fossi | crios: anything java is currently |
| 07:51 | crios__ | Are you serious about that? :) |
| 07:51 | Fossi | sure |
| 07:52 | Chousuke | maybe not the super high performance stuff though. yet, anyway |
| 07:52 | Fossi | i wouldn't want to write a single line of java again if it were up to me |
| 07:52 | Fossi | Chousuke: well, i have rarely seen super high performace java "stuff" |
| 07:52 | clojurebot | ☕ |
| 07:55 | pixelman | I've seen a lot of high-performance java stuff made in vain, designed to for loads exceeding 1000 times the actual use :) |
| 07:57 | pixelman | a lot of java programs are designed performance first usability, maybe later... |
| 07:58 | pixelman | I like not having to fall back on C for high performance stuff though |
| 07:59 | yason | pixelman: I can write a Python program that is designed for loads exceeding 1000 times the actual use. It just depends on the problem space :) |
| 08:01 | pixelman | yep. Most high performance stuff in python use C functions though, that's why it's fast. |
| 08:02 | pixelman | there are some really good stuff in python for number crunching :) |
| 08:02 | ambient | numpy, mainly |
| 08:03 | Fossi | pixelman: same here |
| 08:04 | jdz | i'd prefer (iterate (partial * 2) 1) over (iterate #(* 2 %) 1) any time of day |
| 08:04 | Fossi | the most "high performance" code has been a smallish demo we wrote that reads some data from a memory-mapped file a |
| 08:05 | Fossi | and processes them |
| 08:05 | Fossi | but there is no reason that couldn't work with clojure i guess |
| 08:05 | Fossi | although the immutable datastructures can get a little heavy for the gc (especially on dalvik) |
| 08:06 | pixelman | high performance stuff I dont like working with is when writing an app and everything with the db is a stored procedure. |
| 08:07 | pixelman | but maybe it just sucks to work with from java |
| 08:08 | pixelman | in lisp, maybe it's possible to write a really clean api |
| 08:10 | pixelman | btw. is the a way to easily wrap a java access so that it'll just return nil for a null access? like (.getFoo myVoidObject) |
| 08:10 | pixelman | instead of an exception? |
| 08:11 | Chousuke | (doc .?.) |
| 08:11 | clojurebot | "clojure.contrib.core/.?.;[[x form] [x form & forms]]; Same as clojure.core/.. but returns nil as soon as the threaded value is nil itself (thus short-circuiting any pending computation). Examples : (.?. \"foo\" .toUpperCase (.substring 1)) returns \"OO\" (.?. nil .toUpperCase (.substring 1)) returns nil " |
| 08:11 | pixelman | Chousuke: thanks! |
| 08:11 | Chousuke | I think there's also -?> |
| 08:12 | pixelman | pretty cool |
| 08:14 | LauJensen | jdz: Are you dissing me again? |
| 08:15 | jdz | nope, i'm dissing #() sintax, if anything |
| 08:16 | LauJensen | It's cool :) |
| 08:16 | Chousuke | #() still has its uses though |
| 08:17 | pixelman | ,(.?.toString nil) |
| 08:17 | clojurebot | java.lang.NullPointerException |
| 08:17 | jdz | yes, but when everything else fails only |
| 08:17 | pixelman | how would I go about to use .?. ?? |
| 08:17 | Chousuke | with comp and partial it's sometimes difficult to see what the actual operation is |
| 08:17 | Chousuke | not in this case though. |
| 08:17 | jdz | pixelman: (.?. nil .toString)? |
| 08:18 | jdz | Chousuke: sometimes. is (partial + 2) the case? |
| 08:18 | pixelman | jdz: thankx. am I stupid or what :) |
| 08:19 | Chousuke | jdz: I'm sure I can find you an example from clojurebot's source. a moment... :) |
| 08:20 | jdz | don't take me wrong. i do use #() in places, but as i said, only when everything else makes the code less readable. |
| 08:20 | jdz | it might be just me... |
| 08:20 | LauJensen | I agree jdz, and I'm glad I have you to point it out to me - I really am :) |
| 08:20 | Chouser | (->> (range 10) (filter odd?) (remove #(< 3 % 7))) |
| 08:21 | LauJensen | ~def ->> |
| 08:21 | clojurebot | No entiendo |
| 08:22 | LauJensen | Chouser, it's like -> but runs partial on all expressions? |
| 08:22 | cgrand | LauJensen: it's like -> but adds in last position instead of second |
| 08:22 | jdz | i think it's like ->, only adds the parameter to the end of argument list, not front |
| 08:23 | LauJensen | Thanks guys :) |
| 08:23 | jdz | never used it myself yet |
| 08:24 | jdz | Chouser: that example of yours is where the use of #() is justified and improves code comprehension |
| 08:25 | Chouser | jdz: because 'partial' wouldn't work? |
| 08:29 | jdz | Chouser: yes, it does not fit here |
| 08:29 | jdz | but then, putting arbitrary constants in code is bad |
| 08:30 | Chouser | all of that code was arbitrary. :-) |
| 08:30 | jdz | the remove expression could be replaced by something like (filter good-enough-for-me?) |
| 08:30 | jdz | giving names to things is good |
| 08:30 | Chouser | (def good-enough-for-me? #(< 3 % 7)) |
| 08:30 | jdz | in the long term |
| 08:30 | Chouser | :-) |
| 08:31 | Chouser | now I'm just antagonizing you. |
| 08:31 | jdz | (defn good-enough-for-me? [n] (< 3 n 7)) |
| 08:31 | jdz | replace n by something meaningful for the problem domain |
| 08:31 | clojurebot | for is a loop...in Java |
| 08:31 | jdz | clojurebot: orly? |
| 08:31 | clojurebot | excusez-moi |
| 08:32 | Chousuke | that for factoid triggers way too often |
| 08:33 | jdz | in the end, code that is written and uses #() is a lot better than my unwritten code that does not use #() everywherne |
| 08:33 | jdz | umm, everywhere |
| 08:35 | Chousuke | heh |
| 08:36 | Chouser | "worse is better" in a nutshell |
| 08:37 | Chousuke | you could remove many of the #()s if java methods were automatically wrapped in functions when used as values |
| 08:38 | Chouser | Chousuke: yes, that most annoying ones at that. |
| 08:38 | Chousuke | but I don't know if doing that has any side-effects |
| 08:39 | Chouser | And it wouldn't even be that hard for the complier to do it. But then in order to add a type hint (not uncommon in such situations) you'd simply have no way at all to do it and would have to go back to #(.foo #^Hint %) |
| 08:39 | Chouser | (map #^{return-tag String} .toUpperCase ["one" "two"]) ; bleh :-( |
| 08:40 | Chouser | (map #^{:return-tag String} .toUpperCase ["one" "two"]) ; even worse |
| 08:41 | jdz | (map (java-method .toUpperCase String String) ["one" "two"])... |
| 08:41 | Chouser | (map .toUpperCase #^[String] ["one" "two"]) ; hmmm... |
| 08:41 | Chouser | ,(map #(.toUpperCase #^String %) ["one" "twp"]) |
| 08:41 | clojurebot | ("ONE" "TWP") |
| 08:42 | Chousuke | hm |
| 08:42 | Chousuke | reminds me, I still have to fix my implementation of #() to preserve any metadata :/ |
| 08:43 | Chouser | Chousuke: like for its return value? |
| 08:43 | Chouser | er, wait, what? |
| 08:43 | Chousuke | in my reader. |
| 08:44 | Chousuke | I should also find the time to finish the thing but I've been a bit busy with studying lately |
| 08:44 | Chouser | yeah, but metadata on what? a fn? |
| 08:44 | Chousuke | the #^Foo tag on % |
| 08:44 | Chouser | oh, yeah, on % |
| 08:44 | Chousuke | as it is now my implementation simply replaces the % symbols with gensyms |
| 08:44 | Chouser | I don't the the reader does anything special with % anymore |
| 08:44 | Chouser | ,'% |
| 08:44 | clojurebot | % |
| 08:45 | Chousuke | it does, within #() :/ |
| 08:45 | Chousuke | ,'#(foo %) |
| 08:45 | clojurebot | (fn* [p1__3943] (foo p1__3943)) |
| 08:45 | Chouser | oh |
| 08:45 | Chouser | huh |
| 08:45 | Chouser | I wonder why |
| 08:45 | LauJensen | Chouser: Did you see this? http://www.dzone.com/links/chaos_theory_vs_clojure.html That's my second post which turned jdz against #() :( |
| 08:45 | jdz | i'd like the following to work, too. |
| 08:46 | jdz | ,', |
| 08:46 | clojurebot | EOF while reading |
| 08:46 | Chousuke | jdz: why would you want to quote whitespace? :) |
| 08:46 | jdz | comma is not whitespace :/ |
| 08:46 | Chousuke | yes it is. |
| 08:46 | Chousuke | in clojure :P |
| 08:46 | jdz | i want a symbol whose name is "," |
| 08:46 | Chousuke | (symbol ",") |
| 08:46 | jdz | but yeah, you have a point |
| 08:47 | Chousuke | but that's not very useful |
| 08:48 | Chouser | LauJensen: underscores! |
| 08:49 | jdz | LauJensen: if i'm not a domain expert, i don't have a slightest clue whether #(* (/ (- %1 %2) (- %3 %2)) %4) is correct or not |
| 08:50 | jdz | and you can't tell just by looking at it, too |
| 08:50 | rhickey | underscores - ick |
| 08:50 | jdz | at least you won't after 2 weeks |
| 08:52 | jdz | LauJensen: in your code, whenever i see #(), i see something that derserves a name. really. |
| 08:52 | Chouser | the use of #() in axis-seqs looks ok to me |
| 08:53 | rhickey | lots o swaps in there |
| 08:54 | jdz | Chouser: well, i might have swept some legit cases under the rug here. but i already mentioned the disclaimer ;) |
| 08:54 | Chouser | LauJensen: what it draws is pretty. Nice idea for a blog post! |
| 08:58 | Chouser | rhickey: thanks for ->> Now hiredman can quit doing (-> ... partial ... partial ... partial) :-) |
| 08:58 | crios | come back. what happened to the web freenode chat |
| 08:58 | rhickey | hah |
| 08:59 | rhickey | LauJensen: yes, nice idea |
| 09:00 | rhickey | ,(doc ->>) |
| 09:00 | clojurebot | It's greek to me. |
| 09:02 | LauJensen | Chouser, rhickey, thanks guys |
| 09:03 | Chouser | LauJensen: You could use (while ...) instead of recur in animate |
| 09:03 | LauJensen | Chouser: What benefits would that give me ? |
| 09:04 | Chouser | it makes it more obvious that you've got an imperative loop doing mutation. |
| 09:06 | LauJensen | I guess that's true. Doesn't affect performance or anything like that ? |
| 09:07 | Chouser | ,(macroexpand-1 '(while foo (blah) (blah))) |
| 09:07 | clojurebot | (clojure.core/loop [] (clojure.core/when foo (blah) (blah) (recur))) |
| 09:07 | Chouser | nope, it's the same thing. :-) |
| 09:08 | LauJensen | Ah ok |
| 09:09 | LauJensen | I think I'll hang on to your idea for my "A tribute to Chris Houser" post :) |
| 09:18 | LauJensen | rhickey: your line 'lots o swaps in there', was a comment on my code, would you have modelled it differently? how/why |
| 09:37 | Chouser | LauJensen: nothing about the problem requires mutable state (other than the canvas itself), and as you said the purpose of the atoms are to avoid holding the seq heads, right? |
| 09:38 | LauJensen | yea |
| 09:38 | LauJensen | Put would it have been better to go with something other than atoms to get rid of the head? |
| 09:39 | Chouser | so it's likely there is a way to solve the head-holding problem without resorting to mutable state |
| 09:39 | LauJensen | hmm |
| 09:41 | Chouser | if spawns were a fn instead of a seq, then in 'animate' you could (apply map vector (spawns)) to get a single lazy seq of your "frames" |
| 09:42 | Chouser | then consume that seq using a normal non-head-holding thing (map, for, whatever) |
| 09:44 | Chouser | basically just push those lazy seqs further down into your code instead of trailing off at 'spawns' |
| 09:45 | Chouser | I understand you have swing at the other end trying to push side-effects and statefulness up, so there's definite tension there. |
| 09:45 | LauJensen | Ok, I'll try to model it that was for my 3D Lorenz attractor - I have a hard time visualising that last map though |
| 09:46 | Chouser | it's actually perfectly legitimate to draw on a swing canvas without waiting for a paint call |
| 09:47 | Chouser | doing it that way would allow you to pass in the data to be drawn rather than having it sitting is some global state for the paint method to fetch. |
| 09:48 | LauJensen | But that would spoil the animation effect wouldn't it ? |
| 09:48 | Chouser | how? |
| 09:49 | crios | Fossi, were you saying that clojure could *really* replace java in any domain application ? |
| 09:49 | LauJensen | I think I misunderstood you, can you explain ? :) |
| 09:50 | Chouser | LauJensen: http://gist.github.com/40012 |
| 09:51 | Chouser | there is code that "animates" drawing into a Frame without any mutable state. It doesn't even use proxy. |
| 09:52 | LauJensen | Oh I see |
| 09:53 | Chouser | It also doesn't do any of that hard math stuff. :-) |
| 09:54 | LauJensen | Would make for a good blog post Chris :) |
| 09:54 | Chouser | it was a good blog post, if I may say so myself. ;-) |
| 09:54 | LauJensen | ( and don't call that sorry presentation you did way back when a 'blogpost' ) |
| 09:55 | Chouser | oh |
| 09:55 | Chouser | yes, I seem to remember you complaining about it at the time. |
| 09:55 | LauJensen | hehe, I'm going back now to find it |
| 09:55 | LauJensen | oh yes now I see... it's awful |
| 09:55 | LauJensen | You really should delete that |
| 09:56 | crios_ | In web applications I don't really expect that for generic day-to-day e-business applications will be an urgence to migrate towards a multicore approach, because: 1) latency on the network hides speed on the multicore servers 2) applications that do needed more computitionally power were and are written with distribuited architectural designs 3) java web frameworks handle any http request into an each own thread. The cost to migr |
| 09:57 | Chouser | crios_: cut off at "cost to migr" |
| 09:57 | crios_ | where do you really believe that clojure have a chance to become a mainstream language? |
| 09:58 | crios_ | Chouser, I think there is a cost to migrate a well oiled java team to a new language + frameworks |
| 09:58 | licoresse | What is the cost? When you're fed up with the verbosity of Java? |
| 09:59 | Chouser | crios_: I think some teams (perhaps mostly new teams?) will find the ability to leverage high-core-count processors with less ceremony than it takes to handle 1 core in java now to be attractive. |
| 10:00 | crios_ | licoresse: Do you really think that a less verbose language has higher business value? how COBOL's life fit here? |
| 10:00 | Chouser | surely many people will never find Clojure attractive. It's sad but I believe it. |
| 10:01 | licoresse | crios_: No, not the way YOU put it, put I am sure you can see other ways |
| 10:02 | licoresse | hopefully the pointy-hair-boss-generation is going to die out, haha |
| 10:02 | Chouser | I think that relational databases as a one-size-fits-all solution is on the decline, and as apps get more hands-on with their data, manipulating stuff in memory from multiple threads simultaneously will start to sound like a better and better idea. |
| 10:02 | licoresse | the ones that are scared to shit of new ideas |
| 10:02 | LauJensen | licoresse: They don't die, they become the bosses of the new bosses :) |
| 10:03 | licoresse | :) |
| 10:03 | Chouser | but without better tools to handle that concurrency, though, it's still a dangerous proposition. Clojure can help address that danger. |
| 10:04 | licoresse | well, what is another 25 years of stagnation |
| 10:04 | crios_ | licoresse: you're doing philosophy here :) I was just questioning if the mere "less-verbosity" Clojure language is really of any business value. I think not. |
| 10:05 | Chouser | I think ruby became so popular largely because of rails, which was built and became popular largely because of ruby's strength in meta-programming (using block iterators, etc.) compared to perl, php, etc. I think Clojure's strong in that regard even if you ignore its strength in speed and concurrency. |
| 10:05 | licoresse | of course not, but clojure is about *more* than verbosity, seriously... |
| 10:06 | licoresse | what do I know, I am just getting excited, as I did when I first discovered Smalltalk |
| 10:07 | licoresse | oh man, I was excited then, turtles all the way down... hehe |
| 10:09 | crios_ | I'm too excited. But we work in very real teams and corporations :) |
| 10:09 | crios_ | and I'd like to see where the clojure language could fit there |
| 10:09 | Chouser | I'm such a lisp weenie now. I look at code in some syntaxy language and it just hurts. :-( |
| 10:10 | licoresse | lisp weenie? |
| 10:10 | Chouser | was my definition there too vague? |
| 10:11 | LauJensen | crios, ever line of code technically represents the posibility for a bug and therefor a maintenance cost. What would you rather maintain, 25.000 lines of C or 3000 lines of Clojure? Calculate a businesscase and get back to me |
| 10:11 | crios_ | I saw some web example written in clojure. It does not seem more readable than a scriplet jsp |
| 10:11 | licoresse | no, I was just surprised |
| 10:11 | crios_ | "scripleted" |
| 10:11 | crios_ | the code have to be readable |
| 10:11 | Chouser | licoresse: ah. well, "zealot" doesn't quite fit because I don't feel the need to convert someone if they're happy where they are. |
| 10:12 | crios_ | see here: http://jng.imagine27.com/articles/2009-09-12-122605_pong_in_clojure.html |
| 10:12 | crios_ | To be honest, this is just plain old spaghetti code! :) |
| 10:12 | Chouser | licoresse: and "aficionado" sounds pretentious and doesn't convey the slight negative connotation I was after. |
| 10:12 | crios_ | see the actionPerformed function |
| 10:13 | licoresse | hmm |
| 10:13 | Chouser | crios_: yeah, that's not particularly idiomatic clojure. too much state |
| 10:13 | crios_ | a java junior should migrate to clojure? never on my team! :D |
| 10:13 | licoresse | there are @ all over the place |
| 10:14 | crios_ | you, for me, are power user, examples to follow if I want to become a clojure developer |
| 10:14 | licoresse | Chouser: personally, I don't mind aficionado |
| 10:14 | licoresse | I am already using a mac, so per def. I am a zealot |
| 10:14 | licoresse | (shit) |
| 10:15 | crios_ | if your code is not so readable , how do I, a wannabe clojure student :), can have stimulus? |
| 10:15 | licoresse | I cannot see why it would be harder to learn a lisp, than to learn something algoish |
| 10:16 | Chouser | licoresse: my point was that I have a new barrier between me and learning a new language. I used to accept I would have to learn a quirky syntax and even looked forward to it to some extent. Now I'd just rather not. I'm not sure that's a positive development for me. |
| 10:16 | licoresse | Chouser: You've come to an end point. There is still something beyond, but you don't need it right now |
| 10:17 | licoresse | I think that is perfectly ok |
| 10:18 | licoresse | I need to go pick up the kids, later folks |
| 10:18 | crios_ | bye |
| 10:19 | crios_ | So, Clojure could replace java (in the mainstream) because databases are going "in the cloud", and because writting a web application with it is much more (funny and) easy? Be honest, people :) |
| 10:21 | stuartsierra | Honest? No Lisp-derivative will ever go mainstream. |
| 10:21 | LauJensen | Ask the question "How could it not" ? Java isn't exactly 'up to date' |
| 10:21 | crios_ | [I've no FUD intent, clearly. Just trying to understand you point of view] |
| 10:21 | crios_ | [your] |
| 10:22 | Chouser | crios_: I'm mearly hopeful that Clojure could become sufficiently popular, not by any means convinced that it will. |
| 10:23 | crios_ | I know (well) LauJensen. But COBOL, too, is decades which is "to be dying". But it was the best language for the business |
| 10:23 | crios_ | thank you Chouser. So I'm not an alien :) |
| 10:23 | dnolen-rec | Chouser: you don't think it's sufficiently popular already? For example I used love reading the twitter search feed on Clojure. Now there's too many mnetions to really bother :) |
| 10:24 | Chouser | where "sufficiently popular" is not "more popular than java" or "the favorite language of more programmers than C#" but simply "widely used enough that everyone who wants to can be earn a living using it" |
| 10:24 | crios_ | +1 Chouser |
| 10:25 | crios_ | Our field was (and is) full of buzz words, and "silver bullets" news |
| 10:25 | Chouser | dnolen-rec: nope, not quite yet. growing pains are inevitable, but my boss still rolls his eyes when I mention it. We've got to get past that. :-) |
| 10:25 | adityo | already making a *living* out of Clojure |
| 10:25 | Chouser | adityo: you are? congrats! |
| 10:25 | dnolen-rec | Chouser: you made you remark just as entered mine. That is a good benchmark: that you can use at your job with noone blinking an eye. |
| 10:26 | crios_ | adityo: really? |
| 10:26 | Chouser | note that my definition there includes rhickey making a living using Clojure, since he wants to. We're not there yet. :-) |
| 10:26 | adityo | Chouser: convinced management to use Clojure instead of Common Lisp |
| 10:27 | adityo | yet to launch our products but development is on |
| 10:27 | crios_ | adityo: in what application domains? What kind of software do you develope? |
| 10:27 | adityo | mainly web dev |
| 10:28 | crios_ | entirely written in clojure? |
| 10:28 | Chouser | adityo: fantastic. |
| 10:28 | adityo | developing the backend for a news portal, using Clojure postgres and Java |
| 10:29 | crios_ | your clojure code is written by ex-java developers or by ex-common lisp coders? |
| 10:29 | dnolen-rec | crios_: I think web dev and clojure are a really good fit. I actually wanted to use it on an open source project, but just not yet a wise option. perhaps another benchmark. |
| 10:29 | adityo | i am a ex common lisper.. |
| 10:30 | crios_ | so adityo didn't you migrate java developers to clojure, do you? |
| 10:31 | adityo | actually no..but clojure has been a compelling case to prove to management to have Lisp like languages in an 'Enterprise' envirionment |
| 10:32 | rsynnott | I'm not sure that the primary goal of a language should necessarily be to be popular.... |
| 10:33 | crios_ | your management was already accustomed to that, being formerly accustomed to Common Lisp. Yet I see its value :) |
| 10:34 | crios_ | rsynnott: of course not :) Just trying to be honest on its *real-business* applications |
| 10:35 | crios_ | dnolen-rec: why was not clojure the right choice? |
| 10:35 | rsynnott | I think it has applications there |
| 10:35 | rsynnott | not necessarily terribly widespread applications |
| 10:35 | rsynnott | (if nothing else, the majority, possibly the vast majority, of all commercial programmers are idiots) |
| 10:36 | crios_ | so the web2 / web-economy / web society is written by idiots? :D |
| 10:37 | crios_ | rsynnott: "there"? where precisely? Again, I'm just trying to understand |
| 10:38 | rsynnott | I think it has applications commercially |
| 10:38 | dnolen-rec | crios_: just that not enough open source devs who know Clojure. so we picked Python. it's just our backend tho. about 10% of the code base. Our project is almost entirely JavaScript. Soon as that's ironed out, I'd like to reimplement that 10% in Clojure for our own internal use :D |
| 10:38 | rsynnott | "so the web2 / web-economy / web society is written by idiots?" - broadly speaking, yes |
| 10:38 | rsynnott | the average quality of commercial code is STUNNINGLY low |
| 10:39 | rsynnott | dnolen-rec: no-one's gotten around to writing a parenscript equivalent, yet? :) |
| 10:40 | dnolen-rec | rsynnott: There was some work on it on the list, but it's only half finished as far I could tell. lots of real usage edge cases that were broken. |
| 10:42 | rsynnott | crios_: in particular, there is a lot of copy-and-paste coding out there; people writing stuff without actually understanding what they're doing |
| 10:42 | rsynnott | you don't need comet if you're only talking TO the server |
| 10:43 | rsynnott | if you're sending data to the CLIENT, then you need comet |
| 10:43 | dnolen-rec | rsynnott: for live debugging. Like Symbolic web. |
| 10:43 | rsynnott | ah :) |
| 10:43 | crios_ | you're right rsynnott |
| 10:43 | crios_ | Plus, add cost-cut operations |
| 10:44 | crios_ | where junior developers replace senior |
| 10:44 | sproingie | hey i'm learning clojure, and have a little familiarity with a lot of languages, and i discovered multimethods, but noticed there wasn't much way to combine them |
| 10:44 | sproingie | is there some common idiom in place to simulate call-next-method? |
| 10:44 | rsynnott | actually, comet is a perfect use-case for clojure; the only decent comet server impls are in java, but obviously no-one really wants to write an app backend in HORRIBLE JAVA :) |
| 10:44 | dnolen-rec | rsynnott: yup. |
| 10:44 | dnolen-rec | sproingle: have you looked at get-method? |
| 10:45 | dnolen-rec | Google should be writing Wave in Clojure. |
| 10:45 | rsynnott | (replacing an older erlang-proxying-to-python comet system) |
| 10:45 | sproingie | dnolen-rec: i'm not sure how i'd use it |
| 10:46 | sproingie | get-method appears to be single-dispatch |
| 10:46 | dnolen-rec | sproingle: if you dispatching on type you can look at the parent of the current type. and find the method for that type. |
| 10:46 | rsynnott | crios_: of course, many senior developers are also incompetent :) |
| 10:47 | sproingie | sure, but i'm not always certain which parameter the next method dispatches on |
| 10:47 | crios_ | anyone here? ;-) |
| 10:47 | rsynnott | (one great downside to these amazing fast computers we now have, with access to the internet for copy-and-pasting, is that it is often possible for incompetents to be successful) |
| 10:47 | Fossi | word |
| 10:48 | sproingie | i guess i could go through each one in order sort of like clos. i'm not intimately familiar with how clos resolves them either |
| 10:48 | crios_ | by the way, about the "cloud" buzzing: http://java.sun.com/javaone/2009/articles/rockstar_click.jsp |
| 10:49 | tmountain | ~logs |
| 10:49 | clojurebot | logs is http://clojure-log.n01se.net/ |
| 10:49 | crios_ | "Lose its hype, lose its fuzziness, and split into a couple of well-defined camps, e.g., render farms; Google/Yahoo search-farms; Amazon-style EC2; plus one or two competitors to Amazon. " |
| 10:49 | crios_ | I think so, too |
| 10:49 | dnolen-rec | sproingle: hmmm, if you want CLOS like behavior I think mikel did some work on a library called generic functions |
| 10:50 | dnolen-rec | sproingle: http://code.google.com/p/explorersguild/wiki/XGModelAndGF |
| 10:50 | rsynnott | to a large extent, the cloud thing is just marketing |
| 10:50 | sproingie | dnolen-rec: ooh looks exactly like what i'm looking for, thanks :) |
| 10:51 | dnolen-rec | np |
| 10:52 | crios_ | rsynnott, you see copy&paste as bad, yet it allowed a great sharing of knowledge. In the first days all HTML stuff was "source code available". It endorsed the web sites diffusion - IMHO |
| 10:53 | crios_ | Today, programming as "code snipplets combination" seems to be the future! I don't like that, too |
| 10:54 | rsynnott | very dangerous, though; it allows people to write software which SEEMS to work, without understanding what they're doing |
| 10:54 | crios_ | more people, lesser quality |
| 10:55 | rsynnott | I suspect the Great Recession is driving up the quality if programmers to an extent by reducing the size of the job market |
| 10:55 | crios_ | so, your question was: can this "idiots" people really understand clojure? |
| 10:55 | rsynnott | I suspect that they might have more trouble with it than, say, php or java |
| 10:55 | rsynnott | which is no bad thing :) |
| 10:56 | crios_ | ;) |
| 10:59 | crios_ | adityo: is it yours? :O http://ericlavigne.wordpress.com/2008/12/28/using-postgresql-with-compojure/ |
| 11:00 | Chouser | shouldn't functional code be *more* amenable to copy&paste than procedural code? |
| 11:02 | rsynnott | in general, people who do copy-and-paste programmng will not learn new things :) |
| 11:02 | crios_ | Chouser: good question. Maybe yes . Expecially if uses pure functions |
| 11:02 | rsynnott | if clojure were ever to become very big in industry, the same problem would no doubt emerge |
| 11:02 | rsynnott | (as any technology gets more mainstream the average user usually gets stupider) |
| 11:03 | rsynnott | though for whatever reason some are a little resistant; python for instance seems to be extremely offputting to the copy-and-paste crowd |
| 11:04 | crios_ | in general, it depends on how the useful code is refactored into imported libraries |
| 11:04 | crios_ | I mean, fewer code to copy, if it is into a library |
| 11:12 | crios_ | However, coming to the "concurrency" question: I think the real urge, if it has to be, lies on client applications, not server ones. The "multicore revolution" is into the customer market, not in the server. What do you think? Thus Clojure whould matter when writting for example a Swing application |
| 11:13 | Chouser | crios_: will servers not have multiple cores? |
| 11:14 | tmountain | crios_: I think it matters anywhere that there's more than one core |
| 11:14 | crios_ | well, multiprocessor servers are a news? |
| 11:15 | tmountain | crios_: with all the map/reduce fanfare as of late. the divide and conquer approach pretty much guarantees a lot of parallelism on the backend. |
| 11:17 | crios_ | just for fun, an example of an old multiprocessor: http://3.bp.blogspot.com/__QeUMay1P8w/Se2Jtk7R0rI/AAAAAAAABX8/GIRtzZjzLIQ/s1600-h/multiprocessor.jpg |
| 11:17 | crios_ | tmountain: could you explain better the "fanfare" part? |
| 11:21 | tmountain | google's map/reduce framework, yahoo's hadoop, amazon's data crunching service, etc... they've all gained the attention of startup companies across the map as efficient ways of working with large amounts of data |
| 11:21 | tmountain | of course, you could just use one of the existing frameworks out there to do the job for you |
| 11:22 | hamza` | hey guys, how would you transform while(true){ read from socket after a while break} into clojure. i need to read from socket for a while and when conditions are met stop reading? |
| 11:22 | tmountain | but a lot of projects demand a higher level of customization |
| 11:23 | crios_ | tmountain: I understand. So the hype on server side is into the "distributed" processing, maybe? |
| 11:25 | tmountain | tmountain: yeah, that's exactly what I'm saying. a lot of burgeoning companies want to do things like recommendation systems (i.e., netflix five star ratings) or other data intensive tasks |
| 11:25 | tmountain | oops, refere'd to myself there :p |
| 11:26 | tmountain | hamza`: have a look at clojure.contrib.server-socket |
| 11:26 | tmountain | hamza`: probably a good starting point |
| 11:26 | tmountain | crios_: all that kind of stuff lends itself to parallel processing in a big way |
| 11:27 | crios_ | tmountain: mmm still I believe they'll stay just "business niche" |
| 11:27 | crios_ | at least, in short time terms |
| 11:27 | hamza` | tmountain: thx but what i am reading from is not an actual socket. but since it is socket like thats why i refered it a socket my bad. |
| 11:28 | hamza` | i am going to be reading from a packet capture lib when i have enough packets i want to exit. |
| 11:28 | hamza` | loop and process them. |
| 11:30 | tmountain | hamza`: http://en.wikibooks.org/wiki/Clojure_Programming/Concepts#Looping_and_Iterating |
| 11:30 | tmountain | hamza`: a loop / when / recur construct would probably do what you want |
| 11:34 | crios_ | I have to go. Thank you all for the very interesting discussion. |
| 11:34 | crios_ | ciao |
| 11:46 | Chouser | hamza`: (take n (repeatedly #(read-from-socket))) may work, depending on your performance requirements |
| 11:53 | mtm | ,(int (+ 23/9 1/2)) |
| 11:53 | clojurebot | 3 |
| 12:01 | arohner | having hashmaps and the HOF map share the same name is getting annoying |
| 12:02 | arohner | I want to run map on the keys of a map, and I keep saying map |
| 12:02 | Chouser | arohner: yes, it's unfortunate |
| 12:03 | Chouser | You can say hash-map and be inaccurate, or IPersistentMap and be wordy, or clojure.core/map and be wordy the other way ... :-/ |
| 12:03 | mccraig | is there a clojure api for globbing filenames from a directory ? |
| 12:04 | Chouser | mccraig: file-seq might be close to what you want |
| 12:05 | Chouser | or (filter #(re-find #"\.txt" (.getName %)) (-> "/tmp" java.io.File. .listFiles)) |
| 12:08 | ordnungswidrig | Chouser: #"\.txt$" you mean? |
| 12:08 | Chouser | ordnungswidrig: sure |
| 12:08 | ordnungswidrig | Didn't mean to nitpick. |
| 12:08 | Chouser | :-) np |
| 12:09 | Chouser | if we're not willing to nitpick, we're in the wrong field. |
| 12:09 | ordnungswidrig | yeah, fp nitpicking |
| 12:09 | ordnungswidrig | bettern than oo design |
| 12:10 | ordnungswidrig | I wondered why I have such strange 404 requests in my clojure console. But only when working at home. |
| 12:11 | ordnungswidrig | Actually it was my android phone which tried to reach a funambol server at localhost:8080 only when my wlan. |
| 12:11 | ordnungswidrig | *doh* |
| 12:13 | mccraig | Chouser: that should do fine. thx |
| 12:13 | ordnungswidrig | emacs users here? |
| 12:13 | ordnungswidrig | (and awake?) |
| 12:13 | manic12 | yeah |
| 12:13 | manic12 | sorta awake |
| 12:16 | ordnungswidrig | manic12: perhaps you can help me. I use paredit but the matching open paren is only highlighted if the cursor is _behind_ the closing paren -- not on the paren. |
| 12:17 | manic12 | whatever mode I'm using, after you type the closing paren it highlights the opening one |
| 12:20 | ordnungswidrig | hmm. thanks. |
| 12:20 | manic12 | sorry i couldn't have been more help |
| 12:25 | ordnungswidrig | manic12: another one. How can I disable the current line highlighting. I don't remember the option / face / variable |
| 12:26 | manic12 | i dunno that one, because mine does not do it by default |
| 12:27 | stuartsierra | ordnungswidrig: turn off hl-line-mode |
| 12:27 | ordnungswidrig | stuartsierra: thax. |
| 12:31 | mtm | global-hl-line-mode will toggle it for all buffers |
| 12:31 | LauJensen | Is there a simple way to get something like "2009-09-11" by subtracting 14 days from today, without involving Joda ? |
| 12:35 | stuartsierra | Weeeel, (.getTime (Date.)) gives you current time as a long, then you could subtract equivalent of 14 days, get another Date, then use java.sql.Date to format it. |
| 12:39 | stuartsierra | or use java.util.Calendar, which is even more complicated |
| 12:40 | manic12 | get-univeral-time...d'oh |
| 13:49 | abedra | are there any geolocation libraries available for clojure yet? |
| 13:52 | dysinger | Hey our clojure projects are getting more and more sophisticated and we noticed some code we depend on depends on asm (by way of maven dependencies) |
| 13:52 | dysinger | the asm version is 3.1 |
| 13:52 | dysinger | what's the version of clojure ? |
| 13:52 | ddonnell | abedra: can you be more specific? |
| 13:52 | dysinger | it's just inlined into the clojure repo right ? |
| 13:52 | abedra | ddonnell: i'm looking to turn addresses into geocodes to draw points on a google map |
| 13:54 | ddonnell | abedra: is there a particular service you want to use for the geocoding? |
| 13:55 | abedra | ddonnell: not in particular, I was just wondering if anyone had started down this path |
| 13:55 | abedra | ddonnell: if not, I will just figure it out |
| 13:57 | ddonnell | abedra: i don't know of any clojure specific ones, but it's pretty easy to use the api's from places like google |
| 13:58 | emacsen | Is there a generic function to take a string and return it as a number? |
| 13:58 | emacsen | there must be, since the repl does it... |
| 14:00 | Chouser | ,(read-string "45M") |
| 14:00 | clojurebot | 45M |
| 14:01 | emacsen | heh- good call :) |
| 14:01 | Chouser | might need *read-eval* false |
| 14:07 | emacsen | Chouser: here's a more complex question... I understand how to dispatch my own functions, but is there a way to control distpatch of str? |
| 14:09 | andysp | abedra: the Fmaps HTTP geocoder is quite simple |
| 14:09 | andysp | doesn't really nead a wrapper lib |
| 14:09 | andysp | *GMaps that is |
| 14:09 | emacsen | andysp: geocoder? |
| 14:09 | Chouser | emacsen: you've got a couple options |
| 14:09 | emacsen | andysp: use geocommons :) |
| 14:10 | Chouser | emacsen: (defmulti my-str ...) (binding [str my-str] ...) |
| 14:11 | emacsen | Chouser: right, so that's essentially my own version of str |
| 14:11 | emacsen | no? |
| 14:12 | Chouser | (proxy [Object] (toString [] ...)) |
| 14:12 | Chouser | or manipulate your namespace 'refers' so that 'str' is your own rather than clojure.core/str |
| 14:13 | Chouser | that's all I can think of. |
| 14:13 | emacsen | Fair nuff |
| 14:13 | emacsen | thx |
| 14:13 | Chouser | oh, print-method is a multimethod, so if that's why you want to tweak it, you can do it at that level |
| 14:13 | emacsen | Chouser: basically I want to be able to print my struct (which I know is just a map) in a specific way |
| 14:14 | emacsen | that's the reason for all this |
| 14:14 | emacsen | andysp_: did you get my previous suggestion? |
| 14:15 | Chouser | emacsen: ah, then print-method will be perfect |
| 14:15 | emacsen | cool thanks! |
| 14:17 | Chouser | (defmethod print-method :my-thing [o w] (.write w (str "#<this is my thing>"))) |
| 14:17 | Chouser | #^{:type :my-thing} ['whatever] ; prints: #<this is my thing> |
| 14:18 | emacsen | thx |
| 14:18 | Chouser | np |
| 14:25 | hamza` | hey guys, i am trying to create a list of string such as 12.1 12.2 12.3 ... to 12.254 using (apply vector (interleave (repeat "12.") (range 1 255))) can i turn this in to a vector os strings? |
| 14:27 | Chouser | ,(vec (map #(str "12." %) (range 1 12))) |
| 14:27 | clojurebot | ["12.1" "12.2" "12.3" "12.4" "12.5" "12.6" "12.7" "12.8" "12.9" "12.10" "12.11"] |
| 14:28 | hamza` | lol thx, much shorter than what i was thinking. |
| 14:28 | hamza` | (map str (partition 2 (apply vector (interleave (repeat "12.") (range 1 255))))) |
| 14:29 | Chouser | right. replace str with (partial apply str) |
| 14:30 | Chouser | or #(apply str %) |
| 14:30 | Chouser | and use vec instead of apply vector |
| 14:30 | hamza` | kk thx, yours is much more readable |
| 14:30 | Chouser | yours might be required depending on specifics. :-) |
| 14:32 | licoresse | ,apply |
| 14:32 | clojurebot | #<core$apply__3948 clojure.core$apply__3948@11b8a6b> |
| 14:32 | licoresse | ,(doc apply) |
| 14:32 | clojurebot | "([f args* argseq]); Applies fn f to the argument list formed by prepending args to argseq." |
| 14:32 | hamza` | for each item in this list i need to call a function with side effects is it ok to use apply or map? |
| 14:33 | Chouser | apply won't do it. map is not for side-effects. try doseq |
| 14:33 | hamza` | ok |
| 14:34 | Chouser | if you need both the side effects and the return value -- you're probably doing something wrong. :-) |
| 14:34 | Chouser | but if you still need both, you could use (doall (map ...)) |
| 14:34 | hamza` | no, no need for return just write to disk for each and i am done |
| 14:34 | licoresse | so doall can be recognized as a smell |
| 14:34 | licoresse | ? |
| 14:35 | licoresse | ,(doc doall) |
| 14:35 | clojurebot | "([coll] [n coll]); When lazy sequences are produced via functions that have side effects, any effects other than those needed to produce the first element in the seq do not occur until the seq is consumed. doall can be used to force any effects. Walks through the successive nexts of the seq, retains the head and returns it, thus causing the entire seq to reside in memory at one time." |
| 14:36 | hamza` | ,(doc vec) |
| 14:36 | clojurebot | "([coll]); Creates a new vector containing the contents of coll." |
| 14:37 | licoresse | ah, this head-retaining-thing... |
| 14:41 | Chouser | well, if you want to force a lazy seq, but not do anything else (like pour it into a vector, for example) than doall is the best choice |
| 14:41 | licoresse | I like the analogy |
| 14:42 | Chouser | and I suppose lazy seqs with side effects aren't inherently wrong, just a little fragile. |
| 14:47 | hamza` | on side effects i have a question i have a ref that holds a list of customers when a new customer is added ref is changes in a dosync block and i would like to write the new structure to disk. i read somewhere that side effects should not be in transactions is this bad desing? |
| 14:48 | Chouser | your design is fine except for the io in dosync |
| 14:48 | technomancy | hamza`: if you set it off in an agent, it will only write if the transaction succeeds |
| 14:48 | technomancy | but it will *not* get you a guaranteed atomic commit-and-write like a real RDBMS |
| 14:49 | Chouser | or you could put a watcher on the ref |
| 14:49 | technomancy | even better |
| 14:50 | hamza` | i am not looking for acid properties i just don't want more than 1 thread write the file and corrupt it. so a watcher is called when transaction succeds? |
| 14:51 | hamza` | and what about checking if something is in the ref or not does that belong in the transaction or should i just use ref-set in dosync? |
| 14:52 | Chouser | hamza`: look at add-watch |
| 14:52 | Chouser | I don't understand your second question. You can look at the contents of a single ref from anywhere at any time |
| 14:54 | hamza` | no i mean say that i have set of values. i need to check the set and only add stuff to it if it does not already contain it. now can i in a dosync check if set contains the element and if not create a new set and update ref. of check outside the transaction and just set ref inside the transaction? |
| 14:54 | hamza` | i mean which one is more idiomatic? |
| 14:56 | Chouser | probably do it all inside a dosync. I think dosync is quite cheap until you start setting things. |
| 14:56 | Chouser | don't use ref-set to update it though, use alter |
| 14:57 | hamza` | performence reasons or something else? |
| 14:57 | hamza` | ,(doc alter) |
| 14:57 | clojurebot | "([ref fun & args]); Must be called in a transaction. Sets the in-transaction-value of ref to: (apply fun in-transaction-value-of-ref args) and returns the in-transaction-value of ref." |
| 14:57 | Chouser | something else. :-) using alter allows you to apply a pure function to state, transitioning it from previous to next state. |
| 14:57 | Chouser | the future is a function of the past [or at least should be] |
| 14:58 | Chouser | ref-set is a blunt instrument, indicating to someone reading your code that you don't care what the previous value was, which is not true when adding an item to a set. |
| 14:59 | hamza` | ok, now i get it. |
| 15:16 | gcv | I could use a little help with macro scope rules: |
| 15:16 | gcv | (let [f1 #(inc %)] (defmacro m1 [x] `(~f1 ~x))) |
| 15:16 | gcv | Then: (m1 12) throws an extremely unhelpful exception. |
| 15:17 | gcv | This idiom works perfectly in Common Lisp. |
| 15:18 | Chouser | I assume that's a simplification? |
| 15:18 | gcv | yes :) but the general idea is to lexically capture a function inside a macroexpansion. |
| 15:19 | Chouser | it seems we use to run into this a lot, but haven't in a while. I also thought we used to get a nicer error message. |
| 15:19 | Chouser | ...trying to remember... |
| 15:20 | sgtarr | run into what? |
| 15:20 | Chouser | this type of question |
| 15:21 | sgtarr | oh |
| 15:21 | Chouser | yes, ok, it has to do with functions not being printable readably. |
| 15:23 | stuartsierra | I would write (defmacro m1 [x] `(let [f# (fn [y#] (inc y#))] (f# ~x))) |
| 15:23 | Chouser | or put the fn in var instead of in a local |
| 15:24 | gcv | alas, this is where simplification bites --- this is for a macro defining macro, where the outer accepts an arbitrary function parameter |
| 15:25 | Chouser | can you not just insert the form of that function? |
| 15:26 | Chouser | oh, I see -- it may itself be a local referring to an anonymous fn rather than the anonymous fn form itself? |
| 15:27 | gcv | live code: http://paste.lisp.org/display/87728 |
| 15:27 | gcv | it's broken in a subtle way right now |
| 15:29 | gcv | if you try to use with-db-env in an external namespace which does not import the functions db-open and db-close, the macroexpansion refers to unavailable symbols. |
| 15:29 | Chouser | the auto-gen-sym won't work across multiple ` |
| 15:29 | gcv | interesting, so that's clearly another problem |
| 15:30 | gcv | actually, the code does work, as long as all symbols are visible |
| 15:30 | Chouser | really! hm. |
| 15:31 | Chouser | ,`(foo var# `var#) |
| 15:31 | clojurebot | (sandbox/foo var__4024__auto__ (quote sandbox/var__4023__auto__)) |
| 15:31 | Chouser | ah, neat! |
| 15:31 | Chouser | `(foo var# `~var#) |
| 15:31 | Chouser | ,`(foo var# `~var#) |
| 15:31 | clojurebot | (sandbox/foo var__4028__auto__ var__4028__auto__) |
| 15:32 | Chouser | you're right! My experience with macro-writing-macros is clearly quite shallow... |
| 15:33 | gcv | anyhow, I've been trying to get around this scoping problem by making sure that arguments to def-with-db-macro get captured for the inner macro. I can guarantee that def-with-db-macro will always have the needed symbols visible. |
| 15:33 | stuartsierra | Don't know if this helps, but I've found macro-writing-macros to be easier by avoiding backquote altogether and creating output forms like (list 'foo ...) |
| 15:34 | gcv | stuartsierra: it's worth a shot, but I think my problem is in scoping rules |
| 15:34 | licoresse | interesting.. |
| 15:34 | Chouser | gcv: you might try using ~`~open-fn instead of ~'~open-fn |
| 15:35 | Chouser | no, scratch that. |
| 15:36 | gcv | the thing about print readably functions... when I try something like my original example in CL, I don't need to (setq *print-readably* t) for it to work |
| 15:37 | gcv | besides, I'm pretty sure it still works even if the function is a closure, and you can't reliably print-readably a closure in CL or in Clojure AFAIK |
| 15:37 | gcv | ^is a closure^closes over something |
| 15:38 | Chouser | I'm out on a limb here, but I think clojure may go through a print step to support AOT compilation to bytecode that CL doesn't need to do. |
| 15:38 | stuartsierra | But in CL #'(lambda ...) is considered a literal. |
| 15:39 | Chouser | another thought: I think you want the macro produced by def-with-db-macro to have a ` in it, so that symbols passed in are resolved in the ns were def-with-db-macro is called |
| 15:40 | Chouser | but I don't even know if that's possible right now since ` is not a shortcut for any special form, but does its work at read-time. |
| 15:40 | Chouser | I think there are plans to change that |
| 15:40 | technomancy | ` doesn't expand to quasiquote? |
| 15:41 | Chouser | technomancy: it's called syntax-quote in clojure, and no I don't think so. |
| 15:41 | Chouser | ,''5 |
| 15:41 | clojurebot | (quote 5) |
| 15:41 | Chouser | ,'`5 |
| 15:41 | clojurebot | 5 |
| 15:41 | gcv | sorry, that went over my head. quasiquote? |
| 15:42 | lpetit | hi all |
| 15:42 | Chouser | one could imagine a ` that at read-time expands to (syntax-quote ...) just like ' reads as (quote ...) |
| 15:43 | Chouser | but that's not what happens now |
| 15:45 | gcv | very interesting |
| 15:48 | gcv | thanks for the answers, guys. I'll hammer at this for a little while more, but I'll probably end up just writing out all with-db-* macros by hand for now |
| 15:48 | Chouser | gcv: a very intersting problem, thanks for sharing. |
| 15:49 | Chouser | gcv: it may be worth posting to the google group -- wider audience and more available time for thought |
| 15:49 | stuartsierra | I think you can't refer to an anonymous function in a macroexpansion. |
| 15:49 | stuartsierra | Because it doesn't have a literal representation. |
| 15:49 | stuartsierra | You can only refer to a locally-bound symbol. |
| 15:49 | Chouser | it would be intruiging if the fact that ` does the namespace qualification at read time means that some kinds of macros can't be produced from other macros. |
| 16:06 | lisppaste8 | Chouser pasted "macro-defining macros across namespaces" at http://paste.lisp.org/display/87734 |
| 16:08 | Chouser | gcv: that might help, but the problem in your case is that instead of a literal foo, you take an argument that may not be a simple symbol. You have one example where it's an anon fn form. |
| 16:09 | gcv | Chouser: that does help. thanks! but you're also right about the fn form making things worse. :( |
| 16:09 | Chouser | so rather than a simple-minded (symbol ...) call, I think you'd have to walk the form qualifying every symbol you find |
| 16:09 | gcv | I'm composing a message to the Google group |
| 16:10 | Chouser | ...which is essentially what ` does, but you can't use that code because it's tied to read-time which is too early for you. |
| 16:10 | Chouser | all of which is separate from your original question, btw. :-) |
| 16:10 | gcv | this particular use isn't worth the effort, either. I don't like the boilerplate with-db* macros I'll end up with |
| 16:11 | Chouser | I mean, your original simplified form demonstrated a different issue. |
| 16:11 | gcv | well, it's a discussion of solving the problem which bit me in the first place |
| 16:11 | gcv | that was just an attempted workaround |
| 16:11 | Chouser | ok, sure. |
| 16:11 | gcv | actually, looking at this message I'm writing, I'm not sure which of the two to attack |
| 16:11 | Chouser | fwiw, the idea of makeing with-open more general has come up before. I think there's a non-macro solution in the works. |
| 16:12 | hiredman | :| |
| 16:12 | hiredman | we just need scopes! |
| 16:12 | hiredman | ~scopes |
| 16:12 | clojurebot | No entiendo |
| 16:12 | hiredman | ~scope |
| 16:12 | clojurebot | scope is at http://paste.lisp.org/display/73838 |
| 16:12 | gcv | hiredman: scopes! if only you knew how badly this code I'm writing could use those |
| 16:12 | Chouser | hm. indeed. |
| 16:13 | hiredman | gcv: I have an implementation that worked (last time I used it, months ago) |
| 16:13 | gcv | hiredman: link? |
| 16:13 | hiredman | just a second |
| 16:14 | gcv | fwiw, I hacked around needing scopes for the time being, but I welcome the opportunity to make my code more useable |
| 16:14 | hiredman | http://github.com/hiredman/clojurebot/blob/90fd15bec80bacd7c41cca41c971279587aa25ae/hiredman/horizon.clj |
| 16:14 | hiredman | called it horizon instead of scope |
| 16:15 | hiredman | the only real testing I did was to make sure rhickey's scope example worked |
| 16:17 | gcv | kinda cool |
| 16:18 | hiredman | it's nice for resouce management |
| 16:18 | gcv | I'm guessing the official implementation wouldn't use dynamic variables for state |
| 16:18 | hiredman | I have no idea |
| 16:18 | gcv | Resource management is precisely what I need it for. I made a lazy-seq based abstraction for database cursors, and ended up with the problem of cleaning them up when they aren't completely consumed. |
| 16:19 | hiredman | you can definitely get into trouble when combining dynamic+lazy |
| 16:21 | hiredman | but with scope(horizon) you can have your database cursor creating function register it's clean up action in the surrounding scope, and it will throw an exception if called outside of a scope |
| 16:23 | dhaza | is the clojure wikibooks.org page a good repo for all the clojure PDFs/ebooks out there? |
| 16:23 | dhaza | freely licensed ones, that is |
| 16:26 | hiredman | I don't know that there are any |
| 16:30 | crios | a maybe stupid question, out of curiosity: in Lisp is there an automatic memory management? |
| 16:30 | mDuff | crios, yes |
| 16:30 | gcv | crios: Lisp is the first language to ever have had a garbage collector. It was written sometime before 1959. |
| 16:31 | crios | yes. I'm reading "Coders at work", and I was assuring to have well understood |
| 16:31 | hiredman | crios: gc has been called part of the dna of lisp |
| 16:32 | crios | After having worked in Lisp and C, when turned to Java it felt a "return to Lisp" |
| 16:33 | crios | it says: "memory management. that functions felt more like functions that subroutines" |
| 16:33 | crios | [he says] |
| 16:33 | gcv | I haven't read the book yet. Is this the Guy Steele interview? |
| 16:34 | sproingie | when functions aren't even first-class objects, i can't see how it's in any form like a return to lisp |
| 16:34 | crios | peter seibel: http://www.amazon.com/Coders-at-Work-Peter-Seibel/dp/1430219483 |
| 16:34 | sproingie | seeing gc as the defining characteristic of lisp is about as warped as it gets |
| 16:35 | gcv | sproingie: it's a common view among a certain generation of hackers. |
| 16:35 | gcv | I had a professor in college who called Java "a weak reimplementation of the semantics of Lisp." |
| 16:35 | sproingie | among those whos first exposure to gc was from lisp |
| 16:35 | sproingie | and to some it would appear, their only |
| 16:35 | gcv | basically yeah |
| 16:35 | hiredman | *cough* |
| 16:36 | crios | sproingie: "there was much more enforced modularity to it. it's always tempting to throw in a goto c code just because it's easy" |
| 16:36 | sproingie | huh |
| 16:36 | sproingie | i've done C for more than a decade, never felt "tempted" to use a goto |
| 16:36 | crios | java enforce more than C to write a structured code |
| 16:37 | hiredman | if you subscribe to the idea that all languages are asymptoticaly approaching lisp, then you could say just about any laungage is "a weak reimplementation of the semantics of Lisp" |
| 16:37 | crios | :) just reporting the thought of Emacs / Netscape hacker |
| 16:37 | dhaza | gotos can make sense if you want to ensure a block of code executes after a complex code chain in a function |
| 16:37 | sproingie | hiredman: subtitle: phil greenspun falls into the turing tarpit |
| 16:38 | sproingie | forward-only gotos aren't so bad in C. mostly because C doesn't have a 'break LABEL' syntax |
| 16:39 | dhaza | right. ive very rarely seen goto abused in actual code |
| 16:39 | dhaza | ie not demonstration code of why goto is bad |
| 16:39 | sproingie | i've seen it to redo a loop body which i tend to think is abuse |
| 16:40 | crios | in java, you can "goto" just to exit loops. But also breaks and continue should be avoided |
| 16:40 | sproingie | but it was in seriously performance-critical code |
| 16:40 | sproingie | so i'd probably have done the same |
| 16:40 | gcv | goto is pretty essential in C for cleaning up resources |
| 16:40 | crios | ok ok, no flame "goto" war now - the times are gone :) |
| 16:40 | sproingie | rule of thumb is you should at least be able to keep the goto and the target label on the same screen |
| 16:41 | crios | interesting |
| 16:41 | crios | in order to enhance its readability |
| 16:41 | ordnungswidrig | sproingie: that rule might work on a 12in terminal, not with today 30in screens |
| 16:41 | sproingie | goto is a crude tool, real hackers use Duff's Device |
| 16:41 | ordnungswidrig | sproingie: and schwartzian transform |
| 16:41 | crios | what? |
| 16:42 | sproingie | schwartzian transform is decorate-sort-undecorate and comes from lisp |
| 16:42 | sproingie | in fact schwartz pointed that out |
| 16:42 | ordnungswidrig | crios: duff's device is a manual loop unrolling using modulo operator and a case switch |
| 16:42 | sproingie | i like how python does it, you pass a 'key' function to sort() |
| 16:42 | ordnungswidrig | sproingie: schwartz is the first thing you lern doing perl |
| 16:43 | ordnungswidrig | does pyhton sort do the schwartz? |
| 16:43 | sproingie | it's built in |
| 16:43 | sproingie | sort(mylist, key=somefunc) |
| 16:43 | sproingie | (sorted() actually but who's counting) |
| 16:44 | sproingie | i do just use the schwartz actually. and yes it looks awful. |
| 16:45 | sproingie | you can use a custom comparator, but it's horribly inefficient |
| 16:45 | sproingie | you have to use one anyway for schwartz but at least it's a generic one |
| 16:46 | sproingie | dealing with collections is why i'd rather use clojure than go back to straight java :) |
| 16:47 | crios | ordnungswidrig: maybe could use a Collections.sort and a custom Comperator |
| 16:47 | cemerick | ah, so many new faces :-) |
| 16:47 | crios | or Comparable |
| 16:47 | crios | who remember :D |
| 16:48 | ordnungswidrig | crios: the point with schwartz is not to transform the key for every single transform. |
| 16:49 | crios | is the goal having an object list sorted? |
| 16:49 | dhaza | crios, yes, but specifically when the comparison takes a long time to compute |
| 16:50 | ordnungswidrig | crios: so schwartz is about caching the result of the key-extraction. |
| 16:50 | dhaza | its a much fancier name than what it actually does |
| 16:50 | crios | mmm "The Schwartzian Transform is notable in that it does not use named temporary arrays." |
| 16:51 | crios | http://en.wikipedia.org/wiki/Schwartzian_transform |
| 16:52 | ordnungswidrig | dhaza: I think it's fameous because it's idiomatic perl. Don't sort without the schwartz :-) |
| 16:53 | crios | "The Schwartzian Transform is a version of a Lisp idiom known as decorate-sort-undecorate, which avoids recomputing the sort keys by temporarily associating them with the input items. This approach is similar to memoization, which avoids repeating the calculation of the key corresponding to a specific input value." |
| 16:53 | crios | interesting |
| 16:54 | crios | so clojure should support it? |
| 16:54 | dhaza | why wouldnt it? |
| 16:54 | dhaza | its just a technique, it has little to do with the language |
| 16:54 | crios | yes, just noting the "memoization" outline |
| 16:56 | dhaza | yes, it should be pretty easy to make idiomatic clojure to handle it :) |
| 16:57 | dhaza | are there any stats on how many people are using clojure in a production env? |
| 17:00 | hiredman | http://www.indeed.com/jobtrends?q=+jruby%2C+groovy%2C+scala%2C+clojure groovy? seriously? |
| 17:00 | dhaza | some kind of joke no doubt |
| 17:01 | dhaza | who knows more..indeed.com or google? http://www.google.com/trends?q=jruby%2C+groovy%2C+scala%2C+clojure&ctab=0&geo=all&date=all&sort=0 |
| 17:01 | crios | well, maybe grails |
| 17:01 | cemerick | dhaza: nope, there's lots of groovy programmers out there |
| 17:01 | cemerick | there's a pile of them building apps on the netbeans platform, as well. |
| 17:01 | crios | the grails framework uses groovy |
| 17:01 | dhaza | wow okay, i didnt have any sense of scale for that data...i added "ruby" to the list and that makes it much more clear about whats going on |
| 17:03 | crios | it seems Scala is the JVM winner :D |
| 17:03 | crios | oops wrong channel :P |
| 17:03 | cemerick | hopefully there won't be one winner again |
| 17:04 | hiredman | well, groovy is also a real word |
| 17:04 | crios | what do you mean cemerick? |
| 17:05 | cemerick | crios: I want a polyglot programming world, with common platforms (jvm and clr) |
| 17:05 | hiredman | I really cannot see scala "winning" |
| 17:05 | crios | hiredman: also scala is a real word (in Italian) |
| 17:05 | cemerick | Someone on the artima thread suggested scala : java :: C++ : C, which is a pretty decent way to look at it |
| 17:06 | cemerick | IMO, of course |
| 17:06 | ordnungswidrig | http://www.indeed.com/trendgraph/jobgraph.png?q=+jruby%2C+scala%2C+clojure%2C+haskell%2C+common+lisp |
| 17:06 | hiredman | and see whatever one thinks of C++ |
| 17:06 | ordnungswidrig | haskell plays a notable as well |
| 17:06 | ordnungswidrig | s/notable/\0 part/ |
| 17:07 | crios | well, a great part! |
| 17:07 | hiredman | first time I've ever seen someone use a backreference in an irc regex correction |
| 17:07 | dhaza | so scala is a hacked together POS that worried more about backwards compatibility with a different language than sanity? |
| 17:08 | hiredman | that is harsh |
| 17:08 | dhaza | i dont really think C++ is a POS |
| 17:08 | dhaza | i quite like it |
| 17:08 | dhaza | but why they made design decisions based on C is beyond my comprehension |
| 17:08 | dhaza | maybe it made sense in 1992 |
| 17:08 | hiredman | I think scala is too tied to OOP |
| 17:10 | crios | well , someone says: I'm aquainted with oop, when if I need can use a more functional approach |
| 17:10 | crios | Scala enables this shift |
| 17:10 | crios | "soft shift" |
| 17:10 | ordnungswidrig | hiredman: I'd expect any serious irc-bot to apply to regex automatically :-) |
| 17:11 | ordnungswidrig | POS? What's a POS? |
| 17:11 | dhaza | piece of shit |
| 17:11 | dhaza | i didnt mean it literally |
| 17:11 | ordnungswidrig | dhaza: :-) But hacked together get's it to the point. |
| 17:12 | dhaza | i speak only like that as someone who had to program in half-broken C++ for a couple years |
| 17:12 | dhaza | symbian OS C++...does not support try/catch, but supports TRAP(), which is heavier weight and dumber than exceptions |
| 17:12 | hiredman | for example, scala-internals has had threads on and off dealing with equality and how to fix it and how broken it is, I think a lot of that problem thems from sticking the equality operator as a method onto classes |
| 17:12 | dhaza | of course, the reason they dont support exceptions is because they are too heavy, so its quite ironic that their "solution" makes the problem worse |
| 17:13 | fsm | Hi, I seek comments on my clojure code, any improvements in style or to make it more idiomatic, if anyone would like to look |
| 17:13 | ordnungswidrig | Can't clojurebot do this yet? |
| 17:14 | hiredman | clojurebot: whose job is it to ensure iodmatic coding? |
| 17:14 | clojurebot | that's j0ni's job |
| 17:14 | ordnungswidrig | In #haskell the bot would convert your code to point-free-style ;-) |
| 17:14 | ordnungswidrig | I doubt point-free would give idiomatic clojure |
| 17:14 | fsm | well, my first try in a lisp/functional language |
| 17:14 | fsm | it's hard to know what is good or bad |
| 17:15 | hiredman | ordnungswidrig: clojure's functions don't have a way of querying arity information |
| 17:15 | hiredman | makes that kind of thing harder |
| 17:15 | hiredman | well, maybe not |
| 17:16 | ordnungswidrig | point-free lisp would make you go nuts because of the number of parents wouldn't it? |
| 17:16 | hiredman | first a transform into -> style, from which point free can fall out pretty easily |
| 17:16 | fsm | if there are any takers, please look to http://code.google.com/p/cray/source/browse/ |
| 17:16 | fsm | any comments are welcome |
| 17:17 | hiredman | http://gist.github.com/184831 |
| 17:18 | ordnungswidrig | hiredman: that cries for a macro to get rid of all those "partial" forms :-) |
| 17:18 | ordnungswidrig | hiredman: but otherwise ice |
| 17:18 | fsm | also, anyone doing project euler? |
| 17:18 | hiredman | ~euler |
| 17:18 | clojurebot | euler is http://clojure-euler.wikispaces.com/ |
| 17:18 | fsm | i have completed 28 questions so far |
| 17:19 | ordnungswidrig | hiredman: is it production code or a example you hackes together? |
| 17:19 | hiredman | that's part of clojurebot |
| 17:19 | ordnungswidrig | hiredman: you're the one behind clojurebot, right? |
| 17:19 | hiredman | ~ticket search Serializable |
| 17:19 | clojurebot | ("#174: Make c.l.Keyword Serializable" "#64: GC Issue 61: \t Make Clojure datatype Java Serializable" "#174: Make c.l.Keyword Serializable" "#64: GC Issue 61: \t Make Clojure datatype Java Serializable" "#98: GC Issue 94: \t (ancestors ClassName) does not include tag ancestors of ClassName's superclasses ") |
| 17:19 | hiredman | yes |
| 17:19 | ordnungswidrig | ~mapcat |
| 17:19 | clojurebot | No entiendo |
| 17:19 | hiredman | ,(doc mapcat) |
| 17:19 | clojurebot | "([f & colls]); Returns the result of applying concat to the result of applying map to f and colls. Thus function f should return a collection." |
| 17:19 | hiredman | ~def mapcat |
| 17:20 | ordnungswidrig | too fast for me |
| 17:21 | crios | what is the "project euler" ? |
| 17:21 | ordnungswidrig | how would I model a datatype like "Either" in clojure? A list? |
| 17:21 | fsm | http://projecteuler.net |
| 17:21 | fsm | programming/math puzzles |
| 17:21 | fsm | a fun challenge if you can resist looking up the answers |
| 17:22 | hiredman | ,(:A {:A 1 :B 2}) |
| 17:22 | clojurebot | 1 |
| 17:22 | hiredman | ,(:B {:A 1 :B 2}) |
| 17:22 | clojurebot | 2 |
| 17:22 | crios | fsm: oh I see, thank you. |
| 17:22 | ordnungswidrig | hiredman: or like that. |
| 17:22 | fsm | beware, it is addictive |
| 17:24 | crios | fsm: I was noting it! |
| 17:25 | ordnungswidrig | hiredman: now make it a monad :-) Say, I have some functions f1,f2,f3 of signature a -> Either a bool. How would I chain them together with short-cuirciting? |
| 17:25 | hiredman | ,(doc -?>) |
| 17:25 | clojurebot | "clojure.contrib.core/-?>;[[x form] [x form & forms]]; Same as clojure.core/-> but returns nil as soon as the threaded value is nil itself (thus short-circuiting any pending computation). Examples : (-?> \"foo\" .toUpperCase (.substring 1)) returns \"OO\" (-?> nil .toUpperCase (.substring 1)) returns nil " |
| 17:26 | kanak | Hi. I'm new to clojure, and I'm not sure how to use a function I've defined in another clj file. |
| 17:26 | ordnungswidrig | ~def -?> |
| 17:27 | crios | what? |
| 17:27 | crios | ,(-?> \"foo\" .toUpperCase (.substring 1)) |
| 17:27 | clojurebot | Unsupported character: \"foo |
| 17:27 | crios | ,(-?> "foo" .toUpperCase (.substring 1)) |
| 17:27 | clojurebot | java.lang.Exception: Unable to resolve symbol: -?> in this context |
| 17:27 | hiredman | kanak: depends on this that and the other, but you can just use load-file |
| 17:27 | ordnungswidrig | How can I get the cwd of the clojure process? |
| 17:28 | hiredman | ugh, clojurebot is out of sync |
| 17:28 | crios | ,(clojure.contrib.core/-?> "foo" .toUpperCase (.substring 1)) |
| 17:28 | clojurebot | java.lang.ClassNotFoundException: clojure.contrib.core |
| 17:29 | kanak | hiredman: is that different from, say using "use" or "require"? |
| 17:29 | hiredman | yes |
| 17:30 | hiredman | ,(use 'clojure.contrib.core/-?> "foo" .toUpperCase (.substring 1)) 14:33 clojurebot : java.lang.ClassNo |
| 17:30 | clojurebot | java.lang.Exception: Unable to resolve symbol: .toUpperCase in this context |
| 17:31 | hiredman | ,(use 'clojure.contrib.core) |
| 17:31 | clojurebot | nil |
| 17:31 | hiredman | ,(-?> "foo" .toUpperCase) |
| 17:31 | clojurebot | "FOO" |
| 17:31 | hiredman | ,(-?> nil .toUpperCase) |
| 17:31 | clojurebot | nil |
| 17:31 | hiredman | ~def -?> |
| 17:32 | hiredman | gar |
| 17:33 | crios | time to go |
| 17:33 | hiredman | ah |
| 17:33 | crios | 'night |
| 17:33 | hiredman | no that is right |
| 17:33 | kanak | hiredman: can't seem to get it to work. I've got two files "simple.clj" and "common.clj" in the same directory. "simple" has a function "one-of" that I want to use in "common". Is load-file the right way to do this? |
| 17:34 | hiredman | kanak: depends, does each file declare it's own namespace? |
| 17:35 | kanak | hiredman: not yet. i'm not sure how to use namespaces either. :( |
| 17:36 | hiredman | ok, then load-file is fine |
| 17:36 | kanak | hiredman: but after i use ns to create the namespace, I can start using "use"? |
| 17:36 | ordnungswidrig | How to I tell the swank repl in which directory to launch clojure? |
| 17:36 | hiredman | ~namespace |
| 17:36 | clojurebot | namespaces are (more or less, Chouser) java packages. they look like foo.bar; and corresponde to a directory foo/ containg a file bar.clj in your classpath. the namespace declaration in bar.clj would like like (ns foo.bar). Do not try to use single segment namespaces. a single segment namespace is a namespace without a period in it |
| 17:37 | kanak | thank you for your help. |
| 17:37 | hiredman | kanak: as long as you have the correct classpath, the correct namespaces, and the correct directory structure |
| 17:37 | hiredman | correct meaning they all reflect the information in the other two |
| 17:38 | kanak | thanks. do you know of any newbie friendly guide to classpaths? |
| 17:38 | hiredman | classpaths are pretty simple |
| 17:39 | kanak | so if i want a package a.b.c, my directory structure has to be a/b/c ? is that correct? |
| 17:39 | hiredman | it's a list of directories or jars to search inside for classes |
| 17:39 | hiredman | yes |
| 17:39 | hiredman | and the directory a is in has to be on the classpath |
| 17:40 | kanak | where/how do i set the classpath? |
| 17:40 | hiredman | via the -cp switch to java |
| 17:40 | kanak | gotcha. thank you so much. let me see if i can get this to work. :) |
| 17:40 | hiredman | the -cp switch and the -jar switch are mutually exclusive, fyi |
| 17:49 | fsm | random question - would mapcat be worse than reduce concat for large collections? |
| 17:50 | ordnungswidrig | quick! Are http header names case sensitive? |
| 17:52 | technomancy | ordnungswidrig: no |
| 17:53 | arbscht | but many implementations care, so in practice, often yes |
| 17:53 | ordnungswidrig | so compojure gives me a map of headers. how do I extract one case-insentively? |
| 17:54 | hiredman | rhickey: how would you feel about a patch that adds a layer of indirection between Agent and Agent.Action |
| 17:55 | hiredman | (headers :header (headers :HEADER)) |
| 17:56 | hiredman | rhickey: I'd like to make it possible to use the agent interface ontop of other executor like things |
| 17:56 | hiredman | (like swingutils/invokeandwait) |
| 17:56 | ordnungswidrig | hiredman: that looks really ugly |
| 17:57 | mtm | hiredman: that reminds me of 'buffalo buffalo...' http://en.wikipedia.org/wiki/Buffalo_buffalo_Buffalo_buffalo_buffalo_buffalo_Buffalo_buffalo |
| 17:58 | hiredman | ordnungswidrig: I'd really hope compojure or the servlet stuff it's built on would convert everything to some consistent case |
| 17:58 | ordnungswidrig | mtm: *buffulo* |
| 17:58 | ordnungswidrig | mtm: arg. I meant "buffalo *g*" |
| 17:58 | sproingie | badgher badger badger badger badgher badger badger badger badgher badger badger badger MUSHROOM MUSHROOM |
| 17:58 | mtm | :) |
| 17:58 | hiredman | if not, it might be possible to create a ring middle ware layer that does it |
| 17:59 | ordnungswidrig | hiredman: It doesn't as doesn't the servlet api. At least jetty doesn't. Ring middleware sounds right. |
| 18:00 | ordnungswidrig | me goes to bed now.... enough parentheses for today. |
| 18:00 | mtm | my dreams have been in s-expressions lately... |
| 18:08 | savanni | I had one of those recently. |
| 18:15 | rhickey | hiredman: for what purpose? |
| 18:28 | cemerick | rhickey: it sounds like the language summit went swimmingly. Somehow I missed that you were giving the keynote... |
| 18:29 | rhickey | cemerick: It went really well, great roomful as was last time. I think the keynote was appropriately provocative and well received |
| 18:30 | cemerick | yeah, I think just the right number of lambs were sacrificed (at least judging from the slides, etc) |
| 18:30 | mtm | is the video of your keynote available yet? |
| 18:36 | cemerick | I've been very sad that the ILC videos haven't made it off their tapes, etc. |
| 18:40 | rhickey | And the state/identity talk from QCon |
| 18:42 | cemerick | rhickey: I take it you haven't heard anything about either of those? |
| 18:42 | cemerick | I wish the ILC had charged $500 a head or something and then had plenty to cover immediate professional dubbing of the tapes, etc. |
| 18:43 | rhickey | I wouldn't hear, they just appear. I have no idea how they schedule the releases |
| 18:43 | hiredman | rhickey: swingutils/invokelater and invokeandwait have the same pattern as sending off to an agent, so I would like to be able to create an Agent with Actions that swingutilities/invokelater themselves |
| 18:43 | rhickey | hiredman: why does it need to be an agent? |
| 18:44 | rhickey | there are lots of particular semantics of agents you might not be able to deliver on top of invokeLater |
| 18:45 | hiredman | like what? |
| 18:47 | hiredman | from what I could tell, the guts of it is taken care of inside Action's doRun, so if that was lifted out into AAction then it could be reused |
| 18:47 | rhickey | I still don't see why it needs to be an agent |
| 18:47 | hiredman | so I can use send and send-off |
| 18:48 | rhickey | so, right there, send-off can block, is that ok on the swing thread? |
| 18:48 | hiredman | it unifies interacting with the event dispatch thread in an async way with clojure's other async construct |
| 18:49 | hiredman | rhickey: send blocks on the thread sending the action doesn't it? |
| 18:49 | rhickey | no |
| 18:50 | rhickey | send and send-off always return immediately |
| 18:50 | rhickey | a blocking action will block the thread pool thread |
| 18:50 | hiredman | oh, right |
| 18:51 | hiredman | but that is do different than invokeandwainting a looping Runnable |
| 18:51 | hiredman | or looping inside an agent action |
| 18:51 | rhickey | so send-off provides additional threads when needed, the event thread doesn't |
| 18:51 | rhickey | not looping, blocking |
| 18:52 | hiredman | a looping action that doesn't complete would block |
| 18:52 | rhickey | block on IO in event thread - big no no |
| 18:52 | hiredman | I am aware |
| 18:53 | rhickey | so the semantics are simply not the same |
| 18:53 | rhickey | making it quite wrong to reuse the calls |
| 18:53 | rhickey | however similar it may feel to you |
| 18:53 | hiredman | :( |
| 18:53 | rhickey | sorry |
| 19:19 | cemerick | it's interesting that the NetBeans project (which is GPL and CDDL) doesn't require contributor agreements of any kind. |
| 19:20 | hiredman | http://www.netbeans.org/about/legal/ca.html <-- orly? |
| 19:21 | cemerick | hiredman: heh, OK, but they're taking my patches without my signing anything |
| 19:22 | hiredman | maybe the assumed you signed it? |
| 19:22 | cemerick | ha |
| 19:22 | cemerick | well, maybe. |
| 19:22 | cemerick | I don't care about my rights in this circumstance at all, but I hope they don't get in trouble for it. |
| 19:24 | cemerick | actually, the patches got put into hg without any attribution to me, so maybe that's good enough for government work as long as I don't complain about it |
| 19:25 | fsm | is there anywhere a todo list for contributing to clojure? |
| 19:26 | fsm | i would be happy to contribute even some grunt work, documentation tidying, that kind of thing |
| 19:26 | technomancy | fsm: there are tickets on assembla; not sure if they include tidying-up work |
| 19:26 | technomancy | ~assembla |
| 19:26 | cemerick | fsm: http://clojure.org/contributing |
| 19:26 | clojurebot | assembla is http://www.assembla.com/spaces/clojure |
| 19:27 | fsm | well, any mundane stuff really |
| 19:27 | cemerick | fsm: man, where were you when Chousuke and I manually moved the backlog to assembla?! ;-D |
| 19:29 | fsm | its a long time since i had enthusiasm about writing code, so i want to put back some effort |
| 19:54 | somnium | anyone who might be able to help with compojure/appengine? (or possibly just jetty + compojure servlet) |
