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00:48 jaimef: is there some sort of apache mod_racket?
00:49 mithos28: jaimef: what features do you want? run racket in apache?
00:50 mithos28: I haven't really used the web server, but what I remember being the simple way to integrate with apache was to run the racket web server behind it
00:50 mithos28: so that apache served the static files and racket served the dynamic content
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01:02 vu3rdd: jaimef: there used to be mod_lisp.
01:03 jaimef: I got it compiled
01:06 vu3rdd: jaimef: I had used mod_lisp long back with guile. guile generated the dynamic content while apache served static ones. it used to work just fine. Have forgotten the details now.
01:17 freakazoid: ooh, match makes me feel like I'm back in Erlang land
01:52 (quit) freakazoid: Quit: Computer has gone to sleep.
02:12 jaimef: omg omg it built!
02:29 (quit) dnolen: Quit: dnolen
02:42 jonrafkind: doom3?
02:48 jaimef: hehe no but I should try
02:48 jaimef: 5.2 on netbsd
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03:32 jaimef ponders how to parse log files with racket
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04:20 noelw: jaimef: Open and port and parse with regexps should work for most formats
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06:54 Blkt: good day everyone
06:54 noelw: Hi. A bit late for you
06:55 noelw: Normally you're on a good few hours earlier
06:55 noelw: Sorry, don't mean to sound like a nag
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10:11 epsil: is there a way to import all of R6RS in one fell swoop?
10:11 epsil: Instead of doing, say, (import (rnrs) (rnrs mutable-pairs (6))) just to get set-car!
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10:17 samth: epsil: no, i don't think so
10:25 epsil: ok
10:26 epsil: hm, geiser's autodoc won't display argument names, just underscores
10:26 epsil: like (foo.scm:baz _ _)
10:26 epsil: is there a way to make it more descriptive?
10:28 epsil: "... autodoc will display, instead of their value, the argument names (or an underscore if Geiser cannot determine the name used in the definition)"
10:29 epsil: but why wouldn't it be able to determine that for a function I've written myself?
10:30 bremner: different module?
10:32 epsil: I'm using #lang racket
10:34 epsil: hm, seems to work now ... weird
10:36 epsil: now it works for user-defined functions, but it cannot tell me anything about things that are defined in #%kernel
10:36 epsil: and it cannot display the source of #%kernel-defined functions (+, set!, ...) either
10:36 epsil: maybe that is why?
10:36 samth: right, those don't have "source" or "argument names" in the same sense
10:36 samth: also, `set!' is not a function
10:37 epsil: nah, of course it's not :)
10:37 epsil: but anyway
10:37 epsil: can autodoc display information about those?
10:38 epsil: or is there perhaps a (display-help 'set! ...) function I can enter at the REPL?
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10:40 epsil: C-c C-d C-d does bring up a [manual] link, which works
10:43 epsil: but is there a way to display "(+ z ...)" in the minibuffer, instead of having to look up the manual entry for "+"?
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10:47 samth: epsil: does C-c C-d C-s work?
10:49 epsil: samth: No, there is a "Not enough arguments for format string" error
10:49 samth: that sounds like a bug in geiser
10:51 epsil: yeah, but autodoc still shows up
10:52 epsil: with the cursor at "cons", I get this: (#%kernel:cons _ _)
10:52 epsil: is that right? or is something missing?
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10:56 samth: cons does have two arguments and is provided from #%kernel
10:57 samth: i don't use geiser, so i don't know if it's supposed to do more than that
10:58 epsil: hm
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11:14 bremner: I seem to recall it is not so good at kernel functions
11:15 bremner: something about if/how the module has been imported.
11:16 bremner: in the actual case of cons, it isn't clear there is much more to say...
11:17 epsil: ah
11:17 epsil: well, as long as it's not an issue with my configuration
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13:00 RacketCommitBot: [racket] plt pushed 6 new commits to master: http://git.io/32jH9w
13:00 RacketCommitBot: [racket/master] Fixing PR10485 - Jay McCarthy
13:00 RacketCommitBot: [racket/master] This fixes 10497 and potentially breaks programs that assume the query of a URL is always a list. I have fixed uses in the Web Server, which I expect is the major thing affected, but much more could be. Therefore I am skeptical this is a good idea just for the representation of ?. So, I'd like other people to review the change and let me know if they think I should revert it. - Jay McCarthy
13:00 RacketCommitBot: [racket/master] Forgot to include doc change - Jay McCarthy
13:09 (join) epsil
13:13 RacketCommitBot: [racket] plt pushed 2 new commits to master: http://git.io/b5nVSw
13:13 RacketCommitBot: [racket/master] Revert "This fixes 10497 and potentially breaks programs that assume the query of a URL is always a list. I have fixed uses in the Web Server, which I expect is the major thing affected, but much more could be. Therefore I am skeptical this is a good idea just for the representation of ?. So, I'd like other people to review the change and let me know if they think I should revert it." - Jay McCarthy
13:13 RacketCommitBot: [racket/master] Revert "Forgot to include doc change" - Jay McCarthy
13:16 jaimef: anyone ever do log parsing with racket?
13:16 jonrafkind: which log
13:16 jonrafkind: you can probably just do the same thing other languages do: regexes
13:16 jaimef: unix logs
13:17 jonrafkind: since there is no rhyme or reason to syslog
13:17 bremner: syslog?
13:17 jaimef: need an rfc #?
13:18 jaimef: sure syslog is a good example but not 100% inclusive of the term "unix logs" :P
13:19 jonrafkind: theres an rfc for unix logs?
13:20 (quit) shofetim: Ping timeout: 252 seconds
13:20 bremner: uh, yeah. What RFC?
13:21 bremner suspects we have a failure to communicate
13:22 jaimef: I was making a joke, as you seemed very "tell me which log! this log? that log?"
13:23 bremner: well, if you want a library, which log is important
13:23 bremner: if you want general advice, I guess you already got it.
13:23 jonrafkind: lets get ice cream
13:24 bremner is in a snow storm, not sure I'm in the mood for ice cream
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13:57 jaimef: bremner: mostly did not want to try to do something ill suited for racket
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14:55 Indecipherable: Has anyone ever thought of implementing CL in Racket
15:01 jonrafkind: yea..
15:01 jonrafkind: I didn't get very far though
15:49 (part) Indecipherable
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17:51 (nick) Curry -> RackN00b
17:53 RackN00b: Hello all! Just wondering if someone might be able to answer a question regarding lambda - specifically, lambda cannot recurse implicitly, correct? I mean for lambda to work on any sort of list that requires incrementing through that list, there has to be another function supplying the recursive data, no?
17:57 (quit) RackN00b: Remote host closed the connection
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17:59 RackN00b: Hi sorry... for some reason my IRC client quit on me - is anyone around ?
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18:06 samth: RackN00b: i don't fully understand your question
18:06 samth: lambda is a syntactic form for creating functions
18:06 RackN00b: Well what I meant is that lambda is just an anonymous function and so can't recurse on its own, can it?
18:07 RackN00b: I was under the impression that in order to recurse, you need to re-apply the function to some smaller "value" working towards a base case...
18:07 RackN00b: With lambda being anonymous, how can you write a command that calls it ?
18:07 (quit) RackN00b: Remote host closed the connection
18:07 samth: RackN00b: yes, that's right, (lambda (x) ...) doesn't have a reference automatically to the function itself
18:07 samth: like this:
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18:08 RackN00b: Sorry - irc quit again - not sure if you said anything :(
18:08 samth: rudybot: (define len (lambda (l) (if (empty? l) 0 (+ 1 (len (rest l))))))
18:08 rudybot: samth: Done.
18:08 samth: RackN00b: yes, that's right, (lambda (x) ...) doesn't have a reference automatically to the function itself
18:08 samth: see the function I just defined
18:09 samth: rudybot: (len (list 1 2 3 4))
18:09 rudybot: samth: ; Value: 4
18:09 RackN00b: Right... the recursion is being handled by len
18:09 samth: yes
18:09 RackN00b: The reason I ask is this: As part of an assignment, I have to write a function that produces the powerset of a list of numbers.
18:09 samth: sure
18:09 RackN00b: That's a bonus question - the first one.
18:10 RackN00b: Which I have done using map and recursing on the numlist
18:10 samth: that makes sense
18:11 RackN00b: The second part is to do it without explicitly recursing. The third part is to do it using only the functions cons? cond empty? empty first rest and lambda. No locals, only one define statement for the whole thing.
18:11 RackN00b: The second part is already blowing my mind - I know I can re-write map using foldr but I still need to call it to recurse. The third part is blowing my mind because it seems that none of those functions inherently recurse on a list.
18:12 samth: RackN00b: this is a homework assignment, right?
18:12 RackN00b: Oh yes!
18:13 samth: so, i don't want to just give you the answer here
18:14 samth: have you seen how to write programs that run forever without explicit recursion?
18:14 RackN00b: No, No - I would hope not...
18:14 RackN00b: That's the thing, no...
18:14 RackN00b: Is there a particular name for that?
18:14 samth: ok, so here's a neat trick:
18:15 samth: rudybot: eval ((lambda (x) (x x)) (lambda (x) (x x)))
18:15 rudybot: samth: error: with-limit: out of time
18:15 freakazoid: Great, you'll slow the flow of programming drones who can barely turn on a computer coming out of college computer science courses by one.
18:15 samth: so, RackN00b, that program runs forever without recursion
18:15 RackN00b: What's wrong with drones? They do charlie-work!
18:16 RackN00b: what does eval do? never seem that before
18:16 samth: RackN00b: eval just tells rudybot to run a particular program
18:16 freakazoid: It evaluates expressions.
18:16 freakazoid: oh rudybot's eval
18:16 freakazoid: It evaluates expressions.
18:16 RackN00b: Is there a drracket equivalent?
18:16 freakazoid: that little area at the bottom
18:17 (quit) realitygrill: Quit: realitygrill
18:17 RackN00b: Oh, sorry - I see what you mean
18:17 freakazoid: there is also (eval expr) where expr is a quoted expression
18:17 freakazoid: not "" quoted, but like (eval '(+ 1 1))
18:18 RackN00b: I see... So is that an example of two lambdas repeatedly feeding each other with the same parameter?
18:19 freakazoid: that's some combinator whose name I can't remember being applied to itself
18:19 RackN00b: Cause you're telling the first lambda to accept a parameter x (a function) and then applying it to itself?
18:19 freakazoid: well do it on paper
18:20 freakazoid: just substitute in the argument for the x's
18:20 RackN00b: So that's pretty cool -> but, how can you get it to stop?
18:20 freakazoid: it doesn't stop
18:20 (quit) cataska: Ping timeout: 244 seconds
18:20 freakazoid: it runs until it hits the edges of rudybox's sandbox
18:20 freakazoid: but maybe that's what you were asking - why doesn't it kill rudybot
18:20 freakazoid: rudybot is implemented using http://docs.racket-lang.org/reference/Sandboxed_Evaluation.html
18:20 RackN00b: cause it thinks it's constantly evaluating new parameters?
18:21 freakazoid: it is
18:21 freakazoid: if you do it on paper you'll see
18:22 freakazoid: A coworker of mine had a shirt that said "For a good time, call" and that expression
18:22 RackN00b: Haha.
18:22 RackN00b: So should I be looking at something like this for my function then? But if it won't end, how will I get the produced list in the end?
18:23 freakazoid: though I think it was written (λx.x) (λx.x)
18:23 freakazoid: err
18:23 freakazoid: (λx.x x)(λx.x x)
18:23 freakazoid: I don't know, I wasn't here when you first asked your question.
18:24 samth: RackN00b: that function won't solve your problem
18:24 samth: but it might give you an idea about how to run things for arbitrarily long times without explicit recursion
18:25 freakazoid: RackN00b: yeah, you're looking for a function that takes another function and makes it recurse :)
18:25 RackN00b: Oh - haha... Here she is: I need to consume a list of numbers and produce the powerset of that list. I have to do this three ways - first, which I've done is to use explicit recursion. No sweat. For the bonus, I need to write it without explicit recursion. Third way is to use only first, rest, empty? empty cons cond and lambda... it's an awesome problem!
18:25 RackN00b: Can you define walls on these sandboxes ? :P
18:26 freakazoid: Racket's sandbox functionality is quite powerful
18:26 freakazoid: you can define exactly what code in the sandbox is allowed to do
18:26 freakazoid: I haven't played with it yet, though.
18:26 freakazoid: I don't think I've ever seen more powerful sandbox functionality, even in Java
18:27 freakazoid: It's one of the reasons I like Racket, though. Nobody else seems to care about sandboxes
18:27 RackN00b: I don't know if that's the solution I am supposed to work with seeing as how we haven't covered anything like that yet - Is there another way? As an aside, is currying particularly useful, real-world ?
18:27 freakazoid: currying is very useful
18:27 samth: RackN00b: unless there's some trick that isn't obvious from your problem statement, i don't see another way
18:27 freakazoid: though scheme implementations generally use something called cut, which is sort of like currying and uncurrying
18:28 freakazoid: (define (add1 x) (cut + <> 1))
18:28 freakazoid: err
18:28 freakazoid: that's wrong
18:28 freakazoid: (define add1 (cut + <> 1))
18:28 RackN00b: Coolio. I'm a little confused as to why that function has been running for a while now and no memory-related message has popped up... if I accidentally invoke struc recursion without termination, it lets me know...
18:29 freakazoid: haha
18:29 samth: RackN00b: that function doesn't ever use any more space than it did at the beginning
18:29 freakazoid: Oh I guess it just never terminates
18:29 freakazoid: I thought it expanded - I never did it on paper :)
18:29 freakazoid: RackN00b: hint: don't pass it to itself.
18:29 samth: think about how it reduces, you'll see that it reduces to exactly itself
18:29 RackN00b: I defined curry as a bonus on my previous assignment as (define (curry f) (lambda (x) (lambda (y) ((f x) y))))) and uncurry as (define (uncurry f) (lambda (x) (lambda (y) (f x y)))) I think that's right...
18:30 RackN00b: Ok, another question on the issue of memory - we use an online submission system - if I were to write a function like that and submit it (Not that I have any intention of doing so - i have a pretty good relationship with the faculty!) does the halting problem not imply that there's no way for them to test if it terminates?
18:31 freakazoid: (uncurry (curry f)) should return the same function
18:31 freakazoid: or rather one that behaves the same
18:31 freakazoid: so if you start with a two argument function you should end up with a two argument function
18:31 RackN00b: ok
18:31 ozzloy: https://gist.github.com/1390220 how do i do cleanup after a test fails?  i tried wrapping it in a with-handlers but i'm catching it
18:31 samth: RackN00b: probably, your course uses something like rudybot, with a timer
18:31 ozzloy: er... i'm not catching it*
18:31 RackN00b: a
18:31 ozzloy: the cleanup code doesn't run, the directory still exists
18:32 samth: ozzloy: you should probably use `test-suite' with the #:before and #:after keywords
18:33 ozzloy: those sound promising
18:33 ozzloy: samth, thanks
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18:34 ozzloy: so does test failure not actually raise an instance of exn:test:check ?
18:35 samth: ozzloy: you also aren't using the appropriate predicate there
18:35 ozzloy: or maybe i'm just reading this wrong? http://docs.racket-lang.org/rackunit/api.html?q=rackunit&q=error&q=find-files&q=filter
18:35 rudybot: http://tinyurl.com/7dmz3dk
18:35 (join) epsil
18:35 samth: you are missing a ?
18:36 (quit) anRch: Quit: anRch
18:36 epsil: what is the simplest way to create a small DSL within an enclosed context?
18:36 epsil: say I want to use "foo" as a shorthand for "foo-function", and I have a special form where such shorthands are allowed:
18:36 epsil: (special-environment (foo) (bar)) => (begin (foo-function) (bar-function))
18:36 epsil: how would I go about implementing "special-environment"?
18:36 ozzloy: samth, same behavior with a ?
18:37 ozzloy: samth, i had it in my actual test, typoed it in this minimal example
18:37 samth: epsil: like this
18:37 epsil: :)
18:38 samth: rudybot: (define (foo-function x) x)  (define-syntax-rule (special-env body ...) (let-syntax ([foo (make-rename-transformer #'foo-function)]) body ...))
18:38 rudybot: samth: e.g. haskell: ("foo"++) python: (lambda x: "foo" + x) (or something)
18:38 samth: rudybot: eval (define (foo-function x) x)  (define-syntax-rule (special-env body ...) (let-syntax ([foo (make-rename-transformer #'foo-function)]) body ...))
18:38 rudybot: samth: Done.
18:38 samth: (special-env (foo 7))
18:38 samth: rudybot: (special-env (foo 7))
18:38 rudybot: samth: error: reference to an identifier before its definition: foo in module: 'program
18:38 samth: damn
18:38 samth: has to be more complicated
18:39 epsil: samth: thx, but say I wanted to use "and" as a shorthand
18:39 samth: do you have a more complete specification?
18:39 epsil: would all calls to "and" be affected, or only the top level?
18:39 samth: which do you want?
18:40 epsil: only the top level
18:41 samth: then just recur over the top-level things and replace the ones you want
18:41 samth: like this
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18:41 samth: (define-syntax (special-env stx) (syntax-case stx () [(_ stuff ...) (map some-function (syntax->list #'(stuff ...)))])))
18:42 epsil: so in other words, that's a bit like macro expansion
18:44 samth: yeah, that's what you want to do, isn't it?
18:45 epsil: yeah, pretty much
18:46 epsil: to make things more concrete
18:46 epsil: say I have a function named "parse-and", which is a parser combinator
18:46 epsil: to create a new parser I can do (parse-and parser1 parser2), but this is cumbersome
18:47 epsil: so what I want is a nice little DSL for my combinators where I can write (and parser1 parser2) instead
18:48 epsil: but, of course, the "parse-and" function may call the RACKET procedure "and", and I don't want my DSL to interfere with that
18:49 epsil: on the other hand, I do want to be able to nest "and" shorthands, e.g., (and (and parser1 parser2) parser3)
18:49 epsil: which would expand to (parse-and (parse-and parser1 parser2) parser3)
18:49 samth: so, you can certainly do taht
18:49 samth: that
18:50 samth: you'd just want to change the meaning of `parse-and' to look at its subcomponents, and see if any of them are `and', and change them to `parse-and'
18:50 (quit) jeapostrophe: Ping timeout: 244 seconds
18:52 epsil: hm
18:52 epsil: I want to do things in two steps
18:53 epsil: 1. transform (and (and ...)) to (parse-and (parse-and ...))
18:53 epsil: 2. call the resulting expression
18:53 epsil: and there may be other shorthands as well, say "or".
18:54 RackN00b: So samth - you mentioned that that particular approach of a non-terminating function wouldn't work... Is that correct?
18:54 samth: epsil: yeah, that's fine
18:54 samth: it should all be pretty easy
18:54 samth: i'll try to make up an example in a sec
18:54 epsil: great
18:55 samth: RackN00b: you need to take the general idea of how that function manages to recur
18:55 samth: which is self-application, as you saw
18:55 RackN00b: I see.
18:55 samth: and figure out how to use that idea to make more useful functions
18:57 RackN00b: If I wanted to define a function using lambda that simply consed the first of a list onto the rest of the list would this be appropriate? (define (foo list) (lambda (x) (list (first x) (rest x))))) ?
18:57 RackN00b: I guess I'm slightly unsure of how to pass parameters to lambda
18:58 samth: lambda  just creates a function
18:59 RackN00b: Sorry... my parens were off - I see that now :
18:59 RackN00b: parameters are supplied to sample just like any function (f x) where f is the function and x is the parameter... got it
19:02 samth: epsil: https://gist.github.com/1390297
19:02 samth: gotta run
19:02 (nick) samth -> samth_away
19:03 epsil: thanks!
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19:04 samth_away: wooo 70 racketeers :)
19:05 jonrafkind: I could make a few more bots join
19:07 epsil: time for sleep
19:07 epsil: thanks for all the help, samth
19:07 ozzloy: samth_away, thanks
19:08 ozzloy: oh wow, there's only 70 people in here?  how is this room not more popular?
19:09 (quit) realitygrill: Client Quit
19:09 ozzloy: samth_away, i got it to work, but i'd like to know why the thing i was trying earlier didn't work
19:09 RackN00b: So I'm trying to filter a list of numbers such that only even numbers remain. My code is this: (define (foo2 list)
19:09 RackN00b: ((lambda (x) ((lambda (y) (cond
19:09 RackN00b: [(even? x) (cons x y)]
19:09 RackN00b: [else y]))(rest list)))(first list)))
19:09 ozzloy: RackN00b, are you not allowed to use filter ?
19:10 RackN00b: Well, this is a self problem but it applies to another where I can't use any abstract list functions.
19:10 ozzloy: icic
19:10 (quit) samth_away: Ping timeout: 260 seconds
19:10 ozzloy: T_T
19:10 RackN00b: The predicate is only being applied to the first item in the list. Can I initiate recursion in a manner similar to this?
19:10 jonrafkind: RackN00b, y is not bound in the even? clause
19:10 asumu: RackN00b: Your code doesn't seem to have any recursion in it.
19:10 asumu: Which will make it pretty hard to process a list, which is recursive.
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19:11 RackN00b: asumu - I know that :d I'm trying to figure out how to recurse using only lambdas
19:11 RackN00b: y is bound to rest of list
19:11 asumu: Oh. Literally only lambdas? Or can you use define?
19:11 ozzloy: RackN00b, recurse using only lambdas?  this looks like a job for... the Y combinator!
19:11 RackN00b: define as in...? a local definition? nope
19:11 RackN00b: y combinator eh?
19:12 ozzloy: yeah, that's exactly what the y-combinator does
19:12 asumu: RackN00b: Basically, the Y combinator is the pure lambda way of doing it. What I mean by define is that often you can get recursion by using names.
19:12 asumu: Which is what define lets you do.
19:12 RackN00b: holy jeebus - To the DrRacket documentation!
19:12 asumu: (give things names)
19:12 RackN00b: neat.
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19:13 asumu: RackN00b: Also, the documentation probably won't mention the Y combinator.
19:13 RackN00b: merde
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19:13 ozzloy: RackN00b, it took me a while to break down the y-combinator step by step.  i searched a ton of the webses to get explanations for it
19:14 ozzloy: damnit
19:14 RackN00b: So the y-combintaor isn't something specific to racket or scheme, but a general cs concept?
19:14 ozzloy: i recorded a presentation of it
19:14 ozzloy: but never uploaded it to youtube
19:14 ozzloy: RackN00b, yes, correct
19:14 RackN00b: neat
19:14 ozzloy: you can see it on rosettacode
19:14 jonrafkind: the y combinator is purely academic
19:15 RackN00b: why is that jonrafkind? Cause there are simpler ways to do things you mean?
19:15 jonrafkind: because you can use define to achieve the same thing in a much easier way
19:15 ozzloy: http://rosettacode.org/wiki/Y_combinator
19:15 jonrafkind: the y combinator is for when you are using the pure lambda calculus, which no one uses to do anything real
19:15 RackN00b: as a side note - does anyone know if you can change the transparency of the definitions/interactions frams in drracket?
19:15 RackN00b: I see...
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19:16 jonrafkind: (define (foo x) (foo (+ x 1))) <-- defines foo and which calls itself recursively
19:17 RackN00b: I wish I could use that :D
19:18 asumu: Your assignment won't let you?
19:18 ozzloy: i'm taking you at your word that you need to use just lambdas
19:18 ozzloy: have you examined that assumption?
19:18 asumu: It seems cruel to make you do that without teaching you the Y combinator.
19:18 jonrafkind: yes, the assignment is likely flawed or you are misunderstanding it
19:18 ozzloy: is this a homework assignment?
19:19 jonrafkind: otherwise its just sadism
19:19 RackN00b: Nope, confirmed with prof - is it a bonus question though, so it's not surprising that they're making us go above and beyond
19:19 RackN00b: Maybe peppered with a dash of sadism as well though
19:19 RackN00b: Only allowed to use: empty? empty cons cons? first rest cond and lambda
19:19 ozzloy: have you already learned how to do regular recursion with names?
19:19 RackN00b: Oh yeah
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19:20 RackN00b: It's a three part question - first is solving however we want - I used map and recursed on the list. Second part is without directly calling the function, which I imagine I can do with a lambda. Third is pure lambda
19:20 ozzloy: also i envy you being somewhere that uses racket in a programming course
19:21 ambrosebs: RackN00b: where are you studying?
19:21 RackN00b: waterloo
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19:22 RackN00b: Ah - sorry - client bailed again - man colloquoy is hating me tonight!
19:22 asumu: Go Canada. :)
19:22 ambrosebs: RackN00b: and why Racket?
19:23 RackN00b: They switch from Java a few years ago for the fundamental course. I think it's pretty cool. I have some experience with Fortran and VB so it's been a nice challenge to start thinking a little differently.
19:23 ambrosebs: wow
19:24 ambrosebs: my university just switched from Java to Python
19:24 ozzloy: https://gist.github.com/1390220 why doesn't this display "hello world!"?
19:24 RackN00b: Neat.
19:24 ozzloy: RackN00b, from java to racket?  haha, oh wow
19:25 ozzloy: RackN00b, are you using the HtDP book?
19:25 RackN00b: So I've done a little reading on the Y combinator - it's defined as its own function and then called within others - no dice... only one define in total for the answer :(
19:25 RackN00b: Yeah HtDP, pretty good text I think.
19:25 RackN00b: I have really really good course notes and pretty awesome profs at the moment though so I've been using the notes a fair bit.
19:25 ozzloy: RackN00b, you don't need to actually define the y-combinator as a function
19:26 RackN00b: Eek - I'm looking at like 6 nested lambdas then  - good times...
19:26 ozzloy: you can just have it as a lambda that gets applied to some other
19:26 ozzloy: extra credit, yeah!
19:28 asumu: ozzloy: Try using dynamic-wind instead of catching the exception.
19:28 RackN00b: That's what I'm trying now...
19:28 RackN00b: parens are killing me :D
19:30 ozzloy: RackN00b, paredit mode in emacs makes the parenpain go away
19:30 RackN00b: Have never used emac
19:30 ozzloy: neither had i several months ago
19:30 ozzloy: june-ish
19:31 RackN00b: Oh - did anyone ever answer about the opacity of the interactions and definitions windows in drracket?
19:31 ozzloy: till then i was a long time vim user
19:31 ozzloy: played golf and beat friends
19:31 RackN00b: Haha...
19:31 asumu: RackN00b: I doubt you can change the opacity. Any reason why you want to?
19:32 RackN00b: Not really - purely cause I like the look of it... I wanna be able to do all my coding in Terminal in OS X but I can't....
19:32 RackN00b: (I just started using a Mac)
19:32 asumu: My guess (without having looked at it closely) is that it would involve hacking DrRacket.
19:32 ozzloy: RackN00b, rainbow-delimiters-mode in emacs does that kinda
19:32 ozzloy: it makes the parens muted colors
19:33 ozzloy: and makes them different colors with openers matching closers
19:33 RackN00b: But I can't run anything in emacs can I?
19:33 ozzloy: geiser
19:33 ozzloy: runs racket
19:33 ozzloy: hold on, phone
19:34 asumu: ozzloy: BTW, I am/was a long-time vim user. Now that I use emacs, I'm still a vim user (evil mode). ;)
19:34 RackN00b: geiser?
19:34 asumu: RackN00b: http://www.nongnu.org/geiser/
19:35 RackN00b: Neat- I'll have to play around with this when I have some time!
19:38 RackN00b: Now to figure out how to write a non-recursive list function with the Y combinator (aka flux capacitor)
19:42 ozzloy: asumu, i'm still a vim user too, it turns out
19:43 ozzloy: RackN00b, have you learned how to do something like fibonacci sequence yet?
19:43 ozzloy: asumu, i'll look into that
19:45 ozzloy: asumu, er... that's cool and all, but i already have a solution for getting the behavior i want
19:45 ozzloy: asumu, i'm still curious why this code _doesn't_ do the behavior i want.  i'm using test-suite with #:after to do the thing i want to do
19:47 ozzloy: gtg again.  asumu thanks anyways!
19:50 asumu: ozzloy: Looks like rackunit's checks will install their own exception handler.
19:50 asumu: So it's probably caught before it gets to your handler.
19:53 RackN00b: Sorry.. had to run outside for a sec... I did fibonacci abd factorial both with explicit recursion and now I'm working on some lambda only functions... tricky
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22:09 RackN00b: Anyone guide me with regards to the y-combinator? Does anyone know of any sample code that uses y-combinator that does what i want - I'm beyond caring about submitting it - I'm just miffed that I can't figure it out!
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22:17 RackN00b: anyone ?
22:17 RackN00b: :(
22:21 offby1: Not me.
22:21 offby1: y-combinator always confused me
22:21 RackN00b: It's awesome but when I've got like seven lambda expressions it' gets ridiculous... I'll bet the solution is like three lines or something...
22:26 freakazoid: haha
22:26 freakazoid: you've already seen the y combinator
22:27 freakazoid: or at least something very close to it
22:30 freakazoid: RackN00b: if the function can't directly recurse (because, for example, it doesn't have a reference to itself at definition time), how might it actually get a reference to itself to call in order to loop?
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22:37 RackN00b: Through another function that its consuming, no?
22:38 RackN00b: I am starting to grasp the concept of the y-combinator but I wish there was a step-by-step method to attack the problem starting from the implicitly recursing function I do have...
22:38 RackN00b: Oh well, it's a moot point now, submitted already :P
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23:54 RacketCommitBot: [racket] plt pushed 2 new commits to master: http://git.io/XMPNHg
23:54 RacketCommitBot: [racket/master] Started on random testing for contracts - Andy Gocke
23:54 RacketCommitBot: [racket/master] Some small cleanups of Andy's contract generator code - Robby Findler