Re: [racket-users] Why are SQLITE queries so slow?

On 3/25/2015 10:03 AM, Renaud wrote: I'm new to Racket, and i would like to know why sqlite queries are so slow in my test program. This program imports some data from a text file into a simple sqlite DB. It takes 35s with the INSERT queries and 5-6s without them. I've done the same thing

Re: [racket-users] Re: Why are SQLITE queries so slow?

On 3/26/2015 10:16 AM, Renaud wrote: Thanks a lot George, for this insightful reply. Your idea about FFI explaining 95% of the overhead looks good... but i wonder: in this case, shouldn't we also see a high cost in bind-prepared-statement alone? Hi Renaud, I'm not sure exactly what you are

Re: [racket-users] accumulators vs foldl? was: Fwd: Rsound question

On 3/25/2015 2:07 PM, 'John Clements' via users-redirect wrote: This is a pedagogic question. The discussion below (forwarded with permission) is basically about the best way to find the maximum value in a vector of length four million, a.k.a. a sound file. Non-tail recursion is problematic; I

Re: [racket-users] How to find most efficient constructs/instructions beside benchmarking?

On 4/6/2015 1:49 PM, Lux wrote: You almost never have to worry about the efficiency of (second x) (cadr x) and (car (cdr x)). There are always bigger fish to fry than that. Sure enough, but what if this simple operation is repeated one billion times? Micro optimization is largely a waste of

Re: [racket-users] How to find most efficient constructs/instructions beside benchmarking?

On 4/13/2015 5:16 PM, Josh Grams wrote: That is helpful, but my basic objection still stands: you're computing with *times* while the claim in the article was about *speeds*, I think. He says 50% more work using the same amount of CPU cycles, which I read as work/time. So you need to take the

[racket-users] http-sendrecv with Google geocode

Hi all, I'm having trouble accessing the Google geocode API using http-sendrecv. Code is: (define (lookup address) (let [ (form-data (alist-form-urlencoded (list (cons 'address address) ))) (response #f) (lat #f)

Re: [racket-users] http-sendrecv with Google geocode

://maps.googleapis.com/maps/api/geocode/json?; http://maps.googleapis.com/maps/api/geocode/json form-data) works if I paste it into a browser. George On Mon, Apr 20, 2015 at 8:37 PM, George Neuner gneun...@comcast.net mailto:gneun...@comcast.net wrote: Hi all, I'm having trouble

Re: [racket-users] web server: database result paging

Hi David, On 4/19/2015 9:51 AM, David Vanderson wrote: On 04/18/2015 12:34 PM, George Neuner wrote: However, to do this, I have to keep the initial id listacross multiple requestsand thatis where I've run into trouble. Thus far, I haven't had to use web server continuations. It seems like

Re: [racket-users] http-sendrecv with Google geocode

Hi Sean, Even weirder when I tried this morning your string-append solution - which I had left in place - worked immediately with no changes from last night. The only thing different is I had closed DrRacket before going to bed and reopened it this morning. Maybe something was wonky in

Re: [racket-users] web server: database result paging

On 4/23/2015 1:45 PM, Jay McCarthy wrote: On Thu, Apr 23, 2015 at 1:35 PM, David Vanderson david.vander...@gmail.com wrote: Jay - is there any connection between a saved continuation and the thread that created it? The values of the parameters are saved in the continuation and inherited from

Re: [racket-users] web server: database result paging

Hi David, On 4/23/2015 1:35 PM, David Vanderson wrote: What I want to do is: create a hash representing the return object - data to return - URL for next page function (if applicable) - URL for prev page function (if applicable) convert the hash to a jsexpr

Re: [racket-users] web server: database result paging

Hi Jay, On 4/24/2015 7:03 AM, Jay McCarthy wrote: On Fri, Apr 24, 2015 at 6:31 AM, George Neuner gneun...@comcast.net wrote: On 4/23/2015 1:45 PM, Jay McCarthy wrote: The values of the parameters are saved in the continuation and inherited from the thread. That's going to be a problem

Re: [racket-users] web server: database result paging

On 4/24/2015 7:36 AM, Jay McCarthy wrote: My point is that ONLY the result of make-parameter and parameterize is saved from the thread. In Racket a parameter has nothing to do with a function argument. I believe you are confused by the two when you say There are 9 arguments If you follow

Re: [racket-users] web server: database result paging

On 4/24/2015 1:29 PM, David Vanderson wrote: It sounds like you are not happy with the continuation model. No. I am just trying to understand how it works and to figure out whether I can work with it. The documentation sometimes is not clear and getting enough information sometimes is like

Re: [racket-users] web server: database result paging

On 4/22/2015 8:12 PM, David Vanderson wrote: On 04/20/2015 05:54 AM, George Neuner wrote: I know I need a different response function. The question was whether embed/url is tied to HTML or can be used in a different context. The documentation (6.1.1) says: When used inside page

Re: [racket-users] How to find most efficient constructs/instructions beside benchmarking?

On 4/12/2015 10:22 AM, Lux wrote: For future reference for who will read this topic: This announcement on sqlite mailinglist seems to at least partially prove my point for usefulness of micro-optimization, something valuable to research from my point of view. 50% faster than 3.7.17 This is

Re: [racket-users] How to find most efficient constructs/instructions beside benchmarking?

Hi Josh, On 4/13/2015 5:37 AM, Josh Grams wrote: On 2015-04-13 12:29AM, George Neuner wrote: Somebody doesn't understand fractions: the numbers show a 33% improvement, not 50%. 3.7 is 50% slower, but 3.8 is only 33% faster. Are you sure? I thought that at first, but those numbers are time

[racket-users] web server: database result paging

Hi all, I have an web server application in which I need to page results of a database query, but I also have to guarantee *exactly-once* statistical processing of each sent result row regardless of how many times it may be sent. Theresults are from a complex join, howeverthe join is

Re: [racket-users] web server: database result paging

On 4/18/2015 5:09 PM, Jay McCarthy wrote: I think the code is pretty simple to read: https://github.com/racket/web-server/blob/master/web-server-lib/web-server/managers/lru.rkt#L42 :-)I just wouldn't know where to look for it. I don't have the Racket source generally available.

Re: [racket-users] web server: database result paging

On 4/18/2015 5:09 PM, Jay McCarthy wrote: It is conceivable to grab the servlet's custodian and look at just the cost of the servlet, but unless there are many servlets, that will basically be the same value. Does that work if there is just one instance of serve/servlet with a big

Re: [racket-users] web server: database result paging

Hi Jay, Thanks. One more question: is there a way to determine the size of the continuation cache so as to write a useful (should I) collect? function for create-LRU-manager?What statistic is the threshold-LRU-manager checking? George On 4/18/2015 4:28 PM, Jay McCarthy wrote: Unless

Re: [racket-users] web server: database result paging

is discussed here: http://docs.racket-lang.org/web-server/servlet.html#%28def._%28%28lib._web-server%2Fmanagers%2Flru..rkt%29._make-threshold-.L.R.U-manager%29%29 Jay On Sat, Apr 18, 2015 at 12:34 PM, George Neuner gneun...@comcast.net wrote: Hi all, I have an web server application in which I need

Re: [racket-users] How to find most efficient constructs/instructions beside benchmarking?

Hi Sean, On 4/14/2015 3:21 PM, Sean Kanaley wrote: I see you also made the same point about English! But I don't get the units. As far as I see it, the algorithm is doing X effective computation per cycle. A faster algorithm is computing more each cycle, And that's where we depart. A more

[racket-users] db: nested transactions

Hi all, I have what I hope is a quick question. WIth appropriate care to pair start and commit/rollback, is it safe to use call-with-transaction and start-transaction together? e.g., (call-with-transaction dbc (lambda () : (start-transaction dbc #:isolation

Re: [racket-users] db: nested transactions

Hi Ryan, On 6/23/2015 12:20 PM, Ryan Culpepper wrote: Yes, that should be fine. One note about your sample code: the isolation mode of inner transactions must be #f (the default); you can't change isolation levels once you've started an outer transaction. Also keep in mind that nested

Re: [racket-users] db: nested transactions

[ Email says sending to the group failed. Apologies if this appears multiple times. ] Hi Ryan, On 6/24/2015 10:06 AM, Ryan Culpepper wrote: On 06/24/2015 07:46 AM, George Neuner wrote: [He asks naively not having looked at the code:] Would it be hard to keep savepoint creation

[racket-users] Re: Keep getting call-with-file-lock/timeout

On Wed, 27 May 2015 08:34:11 -0700 (PDT), N N nawar.noo...@gmail.com wrote: I've been trying to set up Racket for evaluation purposes and due to being on CentOS with no root privileges, I've chosen the Racket minimal distribution. I was able to compile it from source and run it and wanted to

Re: [racket-users] Keep getting call-with-file-lock/timeout

Hi John, On 5/29/2015 12:44 PM, 'John Clements' via Racket Users wrote: On May 28, 2015, at 1:53 PM, George Neuner gneun...@comcast.net wrote: I did see the message from John Clements. I'm not a Racket developer, but superficially it appears to me that the negative delay values John

[racket-users] problems with sql-timestamp and date*

Hi all, Got a wierd problem handling dates. I am retrieving a UTC timestamp from a Postgresql (9.3.9) database, converting it to a date* and then offsetting to a (variable) time zone. eliding a lot of unrelated code: : (require (only-in srfi/19 date-string)

Re: [racket-users] problems with sql-timestamp and date*

Ok, reading the docs more carefully, I realized that *seconds-date* takes a boolean and not a time zone offset, but that doesn't explain why *sql-timestamp-srfi-date* is not working properly. I'm now offsetting the time with (seconds-date (+ (date*-seconds ts #f) (* timezone 60

Re: [racket-users] problems with sql-timestamp and date*

On 8/22/2015 5:50 PM, Jon Zeppieri wrote: On Sat, Aug 22, 2015 at 4:36 PM, George Neuner gneun...@comcast.net wrote: The latter code using date works properly (modulo the time zone field) and gives consistent results, but the former using date* gives inconsistent results. E.g

Re: [racket-users] problems with sql-timestamp and date*

A little more experimenting shows that changing *date*-seconds* to *date-seconds* (no asterisk) in (seconds-date (+ (date*-seconds ts #f) (* timezone 60 60)) #f)) guarantees the time offset always is correct wrt the original UTC time. So it seems that *(seconds-date

Re: [racket-users] problems with sql-timestamp and date*

On 8/22/2015 4:02 PM, Jon Zeppieri wrote: Where exactly do you see sql-timestamp-srfi-date failing? In your examples, what I'm seeing is incorrect translation from UTC to UTC-4, but I don't see where the translation from sql-timestamp to date* is going wrong. Could you point to exactly where you

Re: [racket-users] generalised set! in Racket

On 6/30/2015 5:34 PM, 'John Clements' via Racket Users wrote: On Jun 30, 2015, at 8:10 AM, Alexey Cherkaev alexey.cherk...@gmail.com wrote: ... wouldn't it be beneficial to have such a generalised 'set!' system-wide? I understand that Racket focusses more on immutable structures, but there

Re: [racket-users] set a timeout to tcp-connect

On 7/17/2015 10:16 AM, Matthias Felleisen wrote: On Jul 17, 2015, at 9:31 AM, mazert rom...@elgeekador.net wrote: #lang racket (define (foo) (let* ([a (thread (λ () (let-values ([(p-in p-out) (tcp-connect google.com 80)]) (kill-thread b] [b (thread (λ () (sleep 2) (printf I'll

[racket-users] db: postgresql current_date - timestamptz

Hi all, I'm found something strange with Racket 6.1.1 and Postgresql (9.3.6): SQL that works differently in a Racket query than in the DB console. I have a table defined as create table blah ( a char(15), b char(15), created timestamp with time zone,

Re: [racket-users] db: postgresql current_date - timestamptz

On 7/20/2015 6:08 PM, Jay Kominek wrote: You might be ending up with different timezones set on the different connections, as libpq clients can automatically set/change some session settings that the racket library does not. I'd try running show timezone via both connections, and see what you

Re: [racket-users] web-server: generating HTML with styles

Hi John, On 8/24/2015 4:31 PM, John Clements wrote: On Aug 24, 2015, at 12:35 PM, George Neuner gneun...@comcast.net wrote: I'm trying to generate some very simple web pages - basically success/failure status for URLs followed from an email. However, I can't seem to figure out how

Re: [racket-users] web-server: generating HTML with styles

Hi Matthew, Jay beat you to the answer 8-) [though the list apparently bounced my reply to him] I do appreciate your detailed explanation. I knew that I did not need the html module to use response/xexpr in the web-server, but I was looking for some syntax to add styling to the

Re: [racket-users] web-server: generating HTML with styles

On 8/24/2015 4:49 PM, Jay McCarthy wrote: And if you want to add style attributes on a single element, like the p: htmlbodyp style=color: puce;Yo!/p/body/html Then write `(html (body (p ([style color: puce;]) Yo!))) Thanks Jay! That's exactly what I needed. George -- You received this

[racket-users] Re: Formatting Function

On Mon, 12 Oct 2015 12:28:56 -0400, Deren Dohoda wrote: >Probably racket/format is what you need to look at. >http://docs.racket-lang.org/reference/strings.html#%28mod-path._racket%2Fformat%29 Or SRFI 48: http://docs.racket-lang.org/srfi/srfi-std/srfi-48.html

Re: [racket-users] fail on http server response not actually a failure?

On 10/6/2015 9:25 AM, Tony Garnock-Jones wrote: On 10/06/2015 12:43 AM, George Neuner wrote: > I don't know where to put an error handler to deal with reset conditions > at the end of a request. Maybe Jay has an idea? It feels like exceptions are something that response/full, response

Re: [racket-users] fail on http server response not actually a failure?

On 10/5/2015 11:24 PM, Paolo Giarrusso wrote: It sounded confusing that you could close a connection "too early" after all data was sent. But it makes some sense for AJAX with some sort of persistent connections. Still, no reason for error output to appear — a server has to deal with this, as

Re: [racket-users] fail on http server response not actually a failure?

On 10/6/2015 9:58 AM, Jay McCarthy wrote: I'm not sure if this answers the question... These errors are coming from the Web server response-outputing code failing when the other side closed the connection early. The exception would not be returned to your code, because your code is a function

Re: [racket-users] fail on http server response not actually a failure?

On 10/5/2015 4:40 PM, Paolo Giarrusso wrote: On Monday, October 5, 2015 at 10:21:38 PM UTC+2, Neil Van Dyke wrote: > 'John Clements' via Racket Users wrote on 10/05/2015 03:26 PM: > > is this what I would expect to see if a client just gave up and closed the TCP connection before the response

[racket-users] Re: Racket poster

>> http://www.eecs.northwestern.edu/~robby/logos/ On Sun, 20 Sep 2015 18:52:25 -0400, Neil Van Dyke wrote: > >I have a similar aversion to the Grateful Dead iconography: connotations >of substance abuse, intellectual impairment, countercultural friction, >societal

[racket-users] web-server dispatch and places

Hi all, I'm not sure exactly how to phrase my questions, so let me give a bit of background. I have a fairly large (and growing) web middleware application that uses serve/servlet and currently exposes about 90 function URLs, all of the form "/api//". The application grew precipitously

Re: [racket-users] web-server dispatch and places

On 12/2/2015 7:47 AM, Jay McCarthy wrote: Hi George, The output port (and input port) that a response gets is the real port, meaning that it has a file-descriptor and can be shared across places. I suggest having one serve/servlet place that does the dispatching, forwards the port (perhaps

Re: [racket-users] PSA: alexis/collection is dead, long live data/collection

On 12/6/2015 11:07 PM, Alexis King wrote: More generally, I’m not sure multiple dispatch is needed, though it can be a neat tool at times. I think part of the problem is that multiple dispatch is both hard to reason about and slow to implement in a dynamically-typed language. It’s unclear

Re: [racket-users] Re: racket execution

On 12/4/2015 11:47 AM, Héctor Mc wrote: ... the project is in https://github.com/hmcab/anauj.git , and the server run from generacion-datos/codegen.rkt on the bottom the file. Read the readme file before the execution. At this time I have the application on amazon server to prove it, but

Re: [racket-users] PSA: alexis/collection is dead, long live data/collection

On 12/9/2015 1:41 PM, Alexis King wrote: > On Dec 6, 2015, at 10:03 PM, George Neuner <gneun...@comcast.net> wrote: > > I would disagree that multiple dispatch isn't needed. The Visitor pattern is used fairly frequently in real programs and it is just a overly complex,

Re: [racket-users] PSA: alexis/collection is dead, long live data/collection

On 12/9/2015 9:35 PM, brendan wrote: On Wednesday, December 9, 2015 at 6:22:54 PM UTC-5, gneuner2 wrote: > I *think* Brendan is referring to caching the dispatch path - i.e. once > you've determined the proper function to call for a set of arguments, > you cache the arguments (or their relevant

[racket-users] Re: Typed Racket: Is (- 1 1) equivalent to (- 2 2)?

On Thu, 10 Dec 2015 12:35:34 -0500, Alex Knauth wrote: >In typed racket (- 1 1) and (- 2 2) are equal at runtime, but the type >checker doesn't necessarily know that at compile time. It knows that >(- 1 1) is zero because that's a special case in the type system. But it

[racket-users] Re: Racket in a web page (via Whalesong)

On Wed, 30 Dec 2015 12:33:17 -0800 (PST), Greg Trzeciak wrote: >I am actually more interested with long term viability of Whalesong >than being able to run it right now, hence my questions related to >bootstrapped version (and compiler + expander in Racket). My >current

Re: [racket-users] DrRacket fights `racket` on print behavior in `#lang racket/base`

It's definitely due to printing the values. Notice that it also happens in DrRacket when "show sharing in values" is selected on the Choose Language dialog. I'm not aware of a way to prevent the reader from creating objects with shared structure. You can explicitly disallow use of the #0=

Re: [racket-users] Configuration Files

On 11/18/2015 5:19 PM, Christopher Walborn wrote: I'm looking for a way to read configuration files. The configuration file format can be anything provided it's easily human readable/writable. I found the ApacheConf solution on RosettaCode and may use that, but am wondering if there is a conf

[racket-users] Re: racket users fight for their right to colon keywords

Coming late to this. On Wed, 14 Oct 2015 11:50:41 -0400, Neil Van Dyke wrote: >We are conducting a highly scientific poll. > >The question we want to answer is whether people would like for the >Racket standard languages to have symbols that begin with the colon

Re: [racket-users] Detecting mouse events on top of picts?

On 6/6/2016 8:36 PM, David Christiansen wrote: > That seems overly complicated. Can you not just compare the mouse's > coordinates to the picture's location in the canvas? I don't have a good way to know where the picture itself is - only its bounding box. So if the picture consists of a

Re: [racket-users] Detecting mouse events on top of picts?

On 6/8/2016 10:26 PM, David Christiansen wrote: What I mean is that I'm using draw-pict to cause the contents of a pict to be drawn on a dc<%> that I get from a bitmap%. The bitmap is initialized empty and transparent, and then the pict is drawn to it. I can tell which pixels are affected by

Re: [racket-users] I can't open my previous file

I just realized that you are the author (or at least maintainer) of MrEd-Designer ... so you would know if that file was created by it. :-) George -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop

Re: [racket-users] I can't open my previous file

On 6/6/2016 2:51 AM, 张可星 wrote: 在 2016年6月6日星期一 UTC+8下午2:45:34，gneuner2写道： > On 6/6/2016 2:32 AM, 张可星 wrote: > > > Open the file with a text editor and insert a blank line at the > > > beginning. Then DrRacket will open it. I haven't seen this particular > > > issue previously, but obviously

Re: [racket-users] I can't open my previous file

On 6/6/2016 3:27 AM, 张可星 wrote: I don't have MrEd installed, too.I think it is vim Did you have MrEd installed previously in another version of Racket? I think you mentioned that this was an old file you were trying to open. Your file is in a custom format defined by (lib"read.ss""wxme").

Re: [racket-users] I can't open my previous file

Jun 6, 2016 at 9:00 AM, George Neuner <gneun...@comcast.net <mailto:gneun...@comcast.net>> wrote: On 6/6/2016 3:27 AM, 张可星 wrote: I don't have MrEd installed, too.I think it is vim Did you have MrEd installed previously in another version of Racket? I think yo

Re: [racket-users] Detecting mouse events on top of picts?

On 6/7/2016 3:40 PM, David Christiansen wrote: > Understood. Is it possible to define a region to represent the > clickable areas? This is the way I would do it if possible. > > I haven't done much GUI programming in Racket, so I don't know exactly > what it can do, but in, e.g., Windows GDI

[racket-users] Re: I can't open my previous file

On Mon, 6 Jun 2016 13:34:41 +0100, Laurent wrote: >Ah, so you meant MrEd Designer (MED) then, I wasn't sure :) >(mred was the previous GUI lib, part of DrScheme, whereas MED is an >external package) Sorry for the confusion - I wasn't aware that the design editor went

Re: [racket-users] smtp-send-message to gmail

On 6/7/2016 5:18 AM, Лера Гранкина wrote: I'm trying to send message using the code below, but I always get error "No reply from computer". (require net/smtp net/dns openssl/mzssl net/head) (smtp-send-message (dns-get-address "192.168.5.254" "smtp.gmail.com") "m...@gmail.com"

Re: [racket-users] I can't open my previous file

On 6/5/2016 11:18 PM, 张可星 wrote: When I open my file ,Dr racket told me as below `在读取/home/richard/桌面/TheGame.rkt时出现错误. insert-file in text%: error loading the file (read-from-file-failed)` all my code are lost ,what can I do now? I use Drracket 6.5 on ubuntu 16.04lts I find the same issue

Re: [racket-users] Detecting mouse events on top of picts?

On 6/6/2016 4:45 PM, David Raymond Christiansen wrote: I'm looking for a way to check whether a mouse pointer is on top of a particular pict that has been drawn to a canvas%. Right now, the best I've been able to do is to render the pict to two off-screen bitmaps with different background

Re: [racket-users] I can't open my previous file

On 6/6/2016 2:05 AM, 张可星 wrote: 在 2016年6月6日星期一 UTC+8下午1:44:39，gneuner2写道： > On 6/5/2016 11:18 PM, 张可星 wrote: > > When I open my file ,Dr racket told me as below > > > > `在读取/home/richard/桌面/TheGame.rkt时出现错误. > > insert-file in text%: error loading the file (read-from-file-failed)` > > > > all my

Re: [racket-users] I can't open my previous file

On 6/6/2016 2:32 AM, 张可星 wrote: > Open the file with a text editor and insert a blank line at the > beginning. Then DrRacket will open it. I haven't seen this particular > issue previously, but obviously DrRacket is failing to parse the first line. > > George obviously DrRacket is failing to

[racket-users] Re: upload file with http post an Content-Type is multipart/form

On Fri, 8 Jan 2016 21:32:19 -0500, Neil Van Dyke wrote: >Also, I would not put leading "-" characters in the part boundary >string, even if it doesn't break any servers you test against. I would >use only alphanumeric ASCII characters. Why would they break anything?

[racket-users] Re: upload file with http post an Content-Type is multipart/form

On Sun, 10 Jan 2016 02:35:56 -0500, Neil Van Dyke <n...@neilvandyke.org> wrote: >George Neuner wrote on 01/10/2016 02:22 AM: >> Why would they break anything? Section 5.1.1 of RFC-2046 says: > >By "boundary string" I meant what that RFC section calls "boundary

[racket-users] Re: Racket Web Server Security Vulnerability

On Mon, 8 Feb 2016 11:16:03 -0500, Sam Tobin-Hochstadt wrote: >The vulnerability affects web servers that serve static files using >the `#:extra-static-files` option, including the default value of this >option. Um ... where is that keyword used? Or documented? I'm

[racket-users] Re: Expression-style printing and quotation: helpful or harmful?

On Sun, 7 Feb 2016 22:48:31 -0500, Jay McCarthy wrote: > Here's an idea... a programming language/library where >every question can answer in a few simple sentences with no need for >any long explanations, ever? I think that might already have been done. I vaguely

[racket-users] Re: appending files

On Thu, 28 Jan 2016 07:56:05 -0800 (PST), Scotty C wrote: >you knew this was coming, right? put this into your data structure of choice: > >16 5 1 12 6 24 17 9 2 22 4 10 13 18 19 20 0 23 7 21 15 11 8 3 14 > >this is a particular 5x5 tile puzzle >(#6 in

[racket-users] Re: appending files

On Thu, 28 Jan 2016 07:56:05 -0800 (PST), Scotty C wrote: >> You claim you want filtering to be as fast as possible. If that were >> so, you would not pack multiple keys (or features thereof) into a >> bignum but rather would store the keys individually. > >chasing

[racket-users] Re: appending files

On Thu, 28 Jan 2016 11:49:09 -0800 (PST), Scotty C wrote: >what's been bothering me was trying to get the data into 16 bytes in >a byte string of that length. i couldn't get that to work so gave up and >just shoved the data into 25 bytes. here's a bit of code. i think it's

Re: [racket-users] Re: appending files

On 1/27/2016 10:50 AM, Brandon Thomas wrote: On Wed, 2016-01-27 at 04:01 -0500, George Neuner wrote: > On Tue, 26 Jan 2016 23:00:01 -0500, Brandon Thomas > <bthoma...@gmail.com> wrote: > > > Is there anything stopping you from restructuring > > the data on disk and u

Re: [racket-users] Re: appending files

ers@googlegroups.com> on behalf of George Neuner <gneun...@comcast.net> Sent: Wednesday, January 27, 2016 4:28 AM To: racket-users@googlegroups.com Subject: Re: [racket-users] Re: appending files Sorry. I shouldn't do math at 4am. Ignore the numbers. However, it is still correct that th

[racket-users] Re: appending files

On Wed, 27 Jan 2016 11:17:04 -0800 (PST), Scotty C wrote: >On Wednesday, January 27, 2016 at 2:57:42 AM UTC-6, gneuner2 wrote: > >> What is this other field on which the file is sorted? >this field is the cost in operators to arrive at the key value Is it important to

[racket-users] Re: appending files

On Wed, 27 Jan 2016 19:43:49 -0800 (PST), Scotty C wrote: >> Then you're not using the hash in a conventional manner ... else the >> filter entries would be unique > >using it conventionally? absolutely. it is a hash with separate chaining. You snipped the part I was

Re: [racket-users] appending files

On 1/26/2016 12:39 AM, Scotty C wrote: here's what i'm doing. i make a large, say 1 gb file with small records and there is some redundancy in the records. i will use a hash to identify duplicates by reading the file back in a record at a time but the file is too large to hash so i split it.

[racket-users] Re: appending files

On Fri, 29 Jan 2016 16:45:40 -0800 (PST), Scotty C wrote: >i have a new issue. i wrote my data as char and end records with 'return. i >use (read-line x 'return) and the first record is 15 char. when i use > (read-line-bytes x 'return) i get 23 byte. i have to assume that

[racket-users] Re: appending files

On Thu, 28 Jan 2016 20:32:08 -0800 (PST), Scotty C wrote: >> (current-memory-use) >yup, tried that a while back didn't like what i saw. check this out: > >> (current-memory-use) >581753864 >> (current-memory-use) >586242568 >> (current-memory-use) >591181736 >>

[racket-users] Re: long (16s) pauses in UI associated with OS X, possibly app nap?

On Tue, 23 Feb 2016 08:06:34 -0700, Matthew Flatt <mfl...@cs.utah.edu> wrote: >At Mon, 22 Feb 2016 18:55:59 -0500, George Neuner wrote: >> If you suspect App Nap, have you tried disabling it for DrRacket? > >That's worth a try, but App Nap should be disabled automaticall

Re: [racket-users] long (16s) pauses in UI associated with OS X, possibly app nap?

On 2/22/2016 3:04 PM, 'John Clements' via Racket Users wrote: I have several students who are observing truly impressive UI delays in using DrRacket. Specifically, it often happens when they type a double-quote (“) with “automatic parentheses” enabled, and after typing the key, it will take

Re: [racket-users] Re: appending files

On 1/26/2016 2:51 PM, Scotty C wrote: gneuner2 (george), you are over thinking this thing. my test data of 1 gb is but a small sample file. i can't even hash that small 1 gb at the time of data creation. the hashed data won't fit in ram. at the time i put the redundant data on the hard drive,

[racket-users] Re: appending files

Hi Scotty, I rearranged your message a bit for (my own) clarity. On Tue, 26 Jan 2016 18:40:28 -0800 (PST), Scotty C wrote: >running 64 bit linux mint OS on a 2 core laptop with 2 gb of ram. >the generated keys are random but i use one of the associated >fields for

Re: [racket-users] Re: appending files

Sorry. I shouldn't do math at 4am. Ignore the numbers. However, it is still correct that the byte array will use less space than an array of bignums. George On 1/27/2016 3:54 AM, George Neuner wrote: i run a custom built hash. i use separate chaining with a vector of bignums. i am

[racket-users] Re: appending files

On Tue, 26 Jan 2016 23:00:01 -0500, Brandon Thomas wrote: >Is there anything stopping you from restructuring >the data on disk and using the hash directly from there Scotty's hash table is much larger than he thinks it is and very likely is being paged to disk already.

[racket-users] Re: (eqv? Racket-land Wonderland) -> #t

On Mon, 15 Feb 2016 02:40:28 -0800 (PST), Nota Poin wrote: >On Saturday, February 13, 2016 at 5:35:09 PM UTC, Saša Janiška wrote: >> So, at the end I just wonder how is it that such Wonderland is not >> discovered by much more people? > >Startup is slow. Intractable problem,

[racket-users] Re: How to shut down racket webserver without sudo kill?

On Thu, 10 Mar 2016 15:26:28 -0500, Marc Kaufmann wrote: >tl;dr : What is the 'best' way to start and stop a web server? Is there a >"racket-server die" or similar command which does not use 'kill'? > >Some background: > >I am finally deploying lists of spaghetti-code

Re: [racket-users] racket not W^X?

On 4/5/2016 9:32 AM, Philippe Meunier wrote: Suppose instead the racket web server uses W^X: it has a writable-not-executable page somewhere, the JIT writes code into that page, then uses the mprotect system call to flip the page's permissions from writable-not-executable to

Re: [racket-users] racket not W^X?

On 4/5/2016 9:50 AM, Matthew Flatt wrote: Pro tip for pirates: jump to scheme_eval(). Would that be possible if Racket implemented W^X? George -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving

Re: [racket-users] racket not W^X?

On 4/5/2016 10:01 AM, George Neuner wrote: However, W^X isn't panacea - overrun attacks against the CPU still can result in remote code execution. Of course, that should have been "against the CPU *stack*". George -- You received this message because you are subscribed to the Goo

Re: [racket-users] Re: What do you use macros for?

Hi Dan, On 4/11/2016 6:51 PM, Daniel Prager wrote: On Apr 12, 2016 7:53 AM, "George Neuner" <gneun...@comcast.net> wrote: > > My most common uses are to handle database connections and > to embed free form SQL into Racket code. Care to post one of your examples,

[racket-users] Re: What do you use macros for?

On Wed, 13 Apr 2016 06:45:01 +1000, Daniel Prager wrote: >Thanks George > >Of interest to me is that you eschew the use of syntax-parse / -case / >-rules in favour of a straight syntax->datum -> straight racket -> >datum->syntax solution. I suppose this approach trades

[racket-users] Re: What do you use macros for?

On Fri, 08 Apr 2016 12:10:39 +0100, "Norman Gray" wrote: >Quoting Asumu quoting Matthias: > >>> I'd like to propose that there are three disciplined uses of macros: >>> >>> 1. data sublanguages: I can write simple looking expressions and >>> [...] >>> >>> 2. binding

[racket-users] Re: What do you use macros for?

On Fri, 8 Apr 2016 15:49:32 +0200, Jerzy Karczmarczuk <jerzy.karczmarc...@unicaen.fr> wrote: >Le 08/04/2016 15:40, George Neuner a écrit : > >> Macros (at least Lisp and Scheme style macros) can change the nature >> of the eventual runtime evaluation. > >W

[racket-users] Re: What do you use macros for?

On Mon, 11 Apr 2016 10:25:46 -0400, Matthias Felleisen wrote: >These days I define little macros inside of loops or methods all the time. Same here. My most common uses are to handle database connections and to embed free form SQL into Racket code. George -- You

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