Hi Rodolfo,
Thanks for the suggestion. I ended up reading quite a bit about generators
and found this very appropriate and interesting page:
http://matthias.benkard.de/journal/116.
-Joe
On Sun, Feb 19, 2012 at 7:05 PM, Rodolfo Carvalho wrote:
> On Mon, Feb 20, 2012 at 00:55, Joe Gilray wrote:
> Here's a 136-character version (after unnecessary spaces are removed):
>
> (define (life s)
> (let* ((a bitwise-and)
> (s (bitwise-ior (* s #x111000101000111/1000) s)))
> (a (* (a (- -1 s) (* s 4)) 3/32)
> (/ (- (expt 8 48) 1) 15
>
> -- Jeremiah Willcock
That doesn't wo
? 2012?02?20? 00:25, Bill Markmann ??:
I haven't run into that with DrRacket under xubuntu, but two things to
check:
- if you do a 'sudo apt-get install -s libjpeg'... what is the response?
- cd into /usr/lib and do 'ls -l *.jpeg*' and see what you get; mine
(under xubuntu) looks like:
bill@
On 2/19/12 10:52 PM, Jeremiah Willcock wrote:
Here's a 136-character version (after unnecessary spaces are removed):
(define (life s)
(let* ((a bitwise-and)
(s (bitwise-ior (* s #x111000101000111/1000) s)))
(a (* (a (- -1 s) (* s 4)) 3/32)
(/ (- (expt 8 48) 1) 15
On Sun, 19 Feb 2012, Jeremiah Willcock wrote:
On Sun, 19 Feb 2012, SF wrote:
Here's a rough draft that has tons of room for improvement:
#lang racket
(define glider
(string->number "#x\
01\
001000\
111000\
00\
00\
00\
"))
(define (life s)
(define (c s n)
(if (= -1 n)
On Sun, Feb 19, 2012 at 9:14 PM, Rodolfo Carvalho wrote:
> On Mon, Feb 20, 2012 at 01:07, Robby Findler
> wrote:
>>
>> In the interactions window, free variables are runtime errors not
>> compile time errors (unlike empty applications). If that had been in a
>> module (or in the definitions windo
On Mon, Feb 20, 2012 at 01:07, Robby Findler wrote:
> In the interactions window, free variables are runtime errors not
> compile time errors (unlike empty applications). If that had been in a
> module (or in the definitions window), then you would have gotten
> that, I believe.
>
That's right.
In the interactions window, free variables are runtime errors not
compile time errors (unlike empty applications). If that had been in a
module (or in the definitions window), then you would have gotten
that, I believe.
Robby
On Sun, Feb 19, 2012 at 8:52 PM, Rodolfo Carvalho wrote:
> Hello,
>
>
On Mon, Feb 20, 2012 at 00:55, Joe Gilray wrote:
> Hi Rodolfo,
>
> Thanks for the suggestions. Your re-factoring (no pun intended) of the
> conds really cleaned things up. Much appreciated.
>
> About the unnecessary loops, good point, I simply changed to starting with
> end set to 10 instead of
Hi Rodolfo,
Thanks for the suggestions. Your re-factoring (no pun intended) of the
conds really cleaned things up. Much appreciated.
About the unnecessary loops, good point, I simply changed to starting with
end set to 10 instead of 1000 and I think that helps a lot. I know that
there are othe
Hello,
I ran "(define my-generator (generator () (yield 1) (yield 2 3 4)))" on
DrRacket's Interactions Window, but forgot to require racket/generator
first.
The error message was:
#%app: missing procedure expression; probably originally (), which is an
illegal empty application in: (#%app)
Whic
On Sun, Feb 19, 2012 at 09:10:57PM -0500, Eli Barzilay wrote:
[...]
> Speaking about such transformations and about things like (if E #t #f),
> I have some code which I run against student submissions to find style
> problems like these, and using syntax transformations means that it's
> easy to ma
I love it!
Ron Paul Middle school, 2024, Ms. Anderson's 5th grade:
"But Teacher, when I ran 'StyleNazi' like you told us to, it just came back
with:
'here's a phone card, call your mother...' "
-Joe
On Sun, Feb 19, 2012 at 6:10 PM, Eli Barzilay wrote:
> 20 minutes ago, Rodolfo Carvalho wro
20 minutes ago, Rodolfo Carvalho wrote:
> It is possible to replace a pattern like this:
>
> (cond
> [..a..]
> [else (cond
> [..b..]
> ...)])
>
> With this simpler:
>
> (cond
> [..a..]
> [..b..]
> ...)
Speaking about such transformations and about t
Hello Joe,
I'd like to make a few suggestions also.
~ 1
I repeat what Neil V. said:
Formatting-wise, you might consider generally putting newlines between each
> of the three parts of an "if" form. It's easier to distinguish the parts
> at a
On Sun, Feb 19, 2012 at 7:10 PM, Neil Toronto wrote:
> On 02/19/2012 06:05 AM, Robby Findler wrote:
>>
>> On Sun, Feb 19, 2012 at 12:30 AM, Gary Baumgartner
>> wrote:
>>>
>>> On a more productive note: in Racket code I define and use 'implies' a
>>> lot,
>>> often conjoined, for predicates. It's
On 02/19/2012 06:05 AM, Robby Findler wrote:
On Sun, Feb 19, 2012 at 12:30 AM, Gary Baumgartner wrote:
On a more productive note: in Racket code I define and use 'implies' a lot,
often conjoined, for predicates. It's mainly of declarative value, which is
perhaps why it's uncommon in impleme
On Sun, Feb 19, 2012 at 03:17:49PM -0600, Robby Findler wrote:
>
> If it helps, the usual English construction is "neither A nor B", so
> maybe that's a good memory clue.
That's what I needed! I don't think I'll ever forget now.
-- hendrik
Racket Users list:
http://list
Thanks Gary (and Neil and Robby)
Very enlightening. I didn't know about "when". Of course what you said
about "set!" and "cond" makes perfect sense. Minor mods to your code
(using your set! elimination idea twice and caching (integer-sqrt x)) gives
the code below.
I noticed that I can also rem
> From: Robby Findler
> Sent: Sunday, February 19, 2012 1:32 PM
> Subject: Re: [racket] Computer Language Benchmark Game
>
> Hi guys: this doesn't seem to be a very Racket-specific discussion. Do
> you mind taking it elsewhere? (Feel free to point us to where you go
> if you'd like, just in case
Hi guys: this doesn't seem to be a very Racket-specific discussion. Do
you mind taking it elsewhere? (Feel free to point us to where you go
if you'd like, just in case others want to join in there.)
Thanks,
Robby
On Sun, Feb 19, 2012 at 1:35 PM, Isaac Gouy wrote:
>> From: Eli Barzilay
>
>> Sen
The compiler does not track if a function always returns the same
results to the same inputs, and even if it did, it would have to
figure out where to save the results to reuse them the next time,
something that is tricky to do in the general case. Anyways, doing
this kind of optimization is not so
On Sun, Feb 19, 2012 at 1:03 PM, Hendrik Boom wrote:
> On Sun, Feb 19, 2012 at 07:05:37AM -0600, Robby Findler wrote:
>> On Sun, Feb 19, 2012 at 12:30 AM, Gary Baumgartner
>> wrote:
>> > On a more productive note: in Racket code I define and use 'implies' a lot,
>> > often conjoined, for predic
Applying a lot of what Neil said:
; function to create a list of prime factors of a number
; invoke as (factor n)
(define (factor n)
(let loop-factors ([facts '()] [x n] [start 2] [end 1000]
[candidate-primes (primes-from-to 2 1000)])
(cond [(and (empty? cand
On Sun, Feb 19, 2012 at 02:03:51PM -0500, Hendrik Boom wrote:
> On Sun, Feb 19, 2012 at 07:05:37AM -0600, Robby Findler wrote:
> > On Sun, Feb 19, 2012 at 12:30 AM, Gary Baumgartner
> > wrote:
> > > On a more productive note: in Racket code I define and use 'implies' a
> > > lot,
> > > often co
On Sun, 19 Feb 2012, SF wrote:
Here's a rough draft that has tons of room for improvement:
#lang racket
(define glider
(string->number "#x\
01\
001000\
111000\
00\
00\
00\
"))
(define (life s)
(define (c s n)
(if (= -1 n)
0
(+ (if (bitwise-bit-set? 3080 (ari
Sure it's not the whole reason, but it's one more message that says, "your kind
does not belong." Cookbooks don't really fit, since there are so many written
by both men and women, whereas more technical fields have a hard time getting
female representation.
-Ian
- Original Message -
F
> From: Eli Barzilay
> Sent: Sat, 18 Feb 2012 19:30:58 -0800
-snip-
> To explain some of the background, Issac is the person who is running
> the shootout at the moment. We have had private email conversations
> on this topics before, and I let my frustration from that context show
> through in a
> From: Eli Barzilay
> Sent: Friday, February 17, 2012 8:11 PM
> Subject: Re: [racket] Computer Language Benchmark Game
-snip-
> When submissions are dropped because of a vague "it's too fast",
> that's a bias.
For sake of argument, I'll not even bother asking you to show where anyone
wrote
On Sun, Feb 19, 2012 at 17:03, Hendrik Boom wrote:
>
> The trouble is, I can never remember which of 'nand' and 'nor' is
> which. Either of them could mean 'neither'. But I do know what
> 'neither' means.
>
>
Think of them as composed boolean functions:
- nand is "not and"
- nor is "not or"
`a
On Sun, Feb 19, 2012 at 9:29 AM, J. Ian Johnson wrote:
> Er you may think that's funny, but that kind of gender insentivity is
> what this thread is trying to avoid. The implied
> amount of work to introduce a new character so that the book is gender
> neutral makes (non-half-assed/unintenti
On Sun, Feb 19, 2012 at 07:05:37AM -0600, Robby Findler wrote:
> On Sun, Feb 19, 2012 at 12:30 AM, Gary Baumgartner
> wrote:
> > On a more productive note: in Racket code I define and use 'implies' a lot,
> > often conjoined, for predicates. It's mainly of declarative value, which is
> > perhap
On Sun, Feb 19, 2012 at 1:13 PM, SF wrote:
>
> ; this doesn't
> (for/vector: : (Vectorof Integer)
> ([i 5])
> i)
Unfortunately, Typed Racket does not yet do enough inference to figure
out uses of `for/vector' in all cases, so you will probably need to
write the loop explicitly here.
--
sam th
Joe Gilray wrote at 02/19/2012 12:52 PM:
You are doing "(integer-sqrt x)" a few times, when "x" can't
change in between. You might want to have the code look like
"(integer-sqrt x)" is computed only once in the block of code in
which "x" can't change. Just good practice, IMHO;
#lang typed/racket
; this works
(for/list: : (Listof Integer)
([i 5])
i)
; this doesn't
(for/vector: : (Vectorof Integer)
([i 5])
i)
error:
Type Checker: Error in macro expansion -- insufficient type
information to typecheck. please add more type annotations in:
(for/vector: : (Vectorof
Hi Neil, thanks for the input. My responses inline below:
On Sun, Feb 19, 2012 at 2:02 AM, Neil Van Dyke wrote:
> Some random feedback, from a quick glance at the code (I didn't work
> through the algorithm)...
>
> Do you mean to do "[candidate-primes (primes-from-to 2 1000)]" each time
> that
Thanks, Matthew.
On Sun, Feb 19, 2012 at 11:50, Matthew Flatt wrote:
> Oops --- I should have tried that program more carefully.
>
> The problem seems to be with `or'. If I change to `if', then the
> example runs as intended:
>
> (define (has-negative? l)
> (if (negative? (car l))
> #t
I haven't run into that with DrRacket under xubuntu, but two things to
check:
- if you do a 'sudo apt-get install -s libjpeg'... what is the response?
- cd into /usr/lib and do 'ls -l *.jpeg*' and see what you get; mine (under
xubuntu) looks like:
bill@cheese:/usr/lib$ ls -l *jpeg*
-rw-r--r-- 1 r
i can't run drracket in xubuntu 12.04.
when i typed drracket in terminal,this message showed:
rrandom@rrandom-ThinkPad-Edge:~$ drracket
ffi-lib: couldn't open "libjpeg.so.62" (libjpeg.so.62: cannot open
shared object file: No such file or directory)
=== context ===
/usr/share/racket/collects/rack
*** POPL'13: Call for proposals for co-located events ***
Event dates: 20 -- 22, 26 January 2013
Location: Rome, Italy
Deadline: 22 April 2012
Notification: 30 May 2012
Proposals are invited for workshops and other events to
be co-located with POPL2013. Events can either be sponsore
- Original Message -
From: Neil Van Dyke
To: Racket mailing list
Sent: Sun, 19 Feb 2012 05:40:56 -0500 (EST)
Subject: Re: [racket] sad user face?
John Clements wrote at 02/18/2012 08:48 PM:
> On Feb 18, 2012, at 5:43 PM, Luke Vilnis wrote:
>
>> To weigh in on this - when I was an un
Oops --- I should have tried that program more carefully.
The problem seems to be with `or'. If I change to `if', then the
example runs as intended:
(define (has-negative? l)
(if (negative? (car l))
#t
(has-negative? (rest l
The `or' from `lazy' effectively adds a `!' aroun
On Sun, Feb 19, 2012 at 12:30 AM, Gary Baumgartner wrote:
> On a more productive note: in Racket code I define and use 'implies' a lot,
> often conjoined, for predicates. It's mainly of declarative value, which is
> perhaps why it's uncommon in implementation despite how common it is in
> speci
I've heard privately from several people, and will be getting back to
each of them individually. It seems there's a good amount of interest
in Racket consulting. I'll see what information I can distill for this
email list without spilling anyone's beans.
--
http://www.neilvandyke.org/
__
John Clements wrote at 02/18/2012 08:48 PM:
On Feb 18, 2012, at 5:43 PM, Luke Vilnis wrote:
To weigh in on this - when I was an undergrad, women routinely called themselves
"freshmen."
I think this is becoming less common.
Even Brown U. and the few Seven Sisters that I checked
Some random feedback, from a quick glance at the code (I didn't work
through the algorithm)...
Do you mean to do "[candidate-primes (primes-from-to 2 1000)]" each time
that "factor" is called?
2 and 1000 are magic numbers, and should at least be given names, for
documentation purposes and so
On Sun, Feb 19, 2012 at 07:30, Gary Baumgartner wrote:
> On Sat, Feb 18, 2012 at 09:02:41PM -0500, Stephen Bloch wrote:
> [...]
> > I see a lot of my students doing this -- in whatever language -- because
> they think of Booleans as a way to decide which of two things to DO, rather
> than as legi
Here's a slight reworking of the factor function. I think it is prettier
and my in the spirit of Racket/Scheme.
; function to create a list of prime factors of a number
; invoke as (factor n)
(define (factor n)
(let loop-factors ([facts '()] [x n] [start 2] [end 1000]
[candidate-primes (primes-
On Sat, 18 Feb 2012 23:31:03 -0500
David Van Horn wrote:
> On 2/18/12 9:23 PM, J. Ian Johnson wrote:
> > More important than the word choice, the representative character of the
> > book is male. Potential female readers will not see this book as for them
> > because they don't identify with th
Oh dear...
Neil Matthew Caldwell
On 13 February 2012 07:47, Todd O'Bryan wrote:
> Before this goes too far, I just want to let everyone know that I will
> never kneel to the Neils, nor go to the mat for the Matthews. Now if
> Shriram announced his candidacy for supreme dictator in the
> post-apo
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