Neil Van Dyke | 22 Nov 04:10 2014


Any plans to promote the `unstable/socket` module to non-unstable?

Or to otherwise officially support Unix domain sockets in core Racket?

Neil V.

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Matthias Felleisen | 22 Nov 00:25 2014

Re: Running subset of RackUnit tests

[[ always cc list ]]

(module+ test ...) is a single sub-module that is distributed over the body of a module. Racket collects the
pieces and makes a single submodule. 

-- Matthias

On Nov 21, 2014, at 3:13 PM, Joel McCracken
<mccracken.joel@...> wrote:

> How would I run 1) all tests and 2) a selected subset (i.e. multiple
> modules at once)?
> I'm relatively unfamiliar with Racket's module system (other than it
> exists and how to do basic things with it).
> On Fri, Nov 21, 2014 at 3:00 PM, Matthias Felleisen
> <matthias@...> wrote:
>> I would use submodules to manage selective testing, like this:
>> #lang racket
>> (provide
>>  ;; -> Void
>>  ;; does foo and bar
>>  main)
(Continue reading)

Stephen Chang | 21 Nov 20:34 2014

require and provide from scrbl files?

Is this allowed?

File A.scrbl:

#lang scribble/manual

File B.scrbl:

#lang scribble/manual

 <at> (require "A.scrbl")

Right now when I run B, I get the error:

module: identifier is already imported in: doc
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Joel McCracken | 21 Nov 19:59 2014

Running subset of RackUnit tests


I have a I'm trying to figure out how to run specific test subsets. I
have organized different subsets into test suites, and do run-tests on
each of them, but I would prefer a scheme where:

1) I can run all of the tests for a project, and
2) I can "tag" tests to run subsets.

Is there a way to accomplish this?

Thanks in advance
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Matt Gushee | 21 Nov 09:07 2014

Socket error with distributed places example


I am learning about distributed places, and I tried to run the "hello
world" example found at . I get the
following error:

> uncaught exception: "socket error connecting to localhost:6344"

I tried a couple of other port numbers, just in case 6344 was in use
(in fact, it was in use when I first tried it, but I killed the
program that was using it), but got the same results.

Any tips for debugging this? I suppose I can fire up Wireshark, but
... urgh. Hoping this is a common problem with common causes. Perhaps
I should mention that I am new to Racket, but having a fair amount of
experience with Scheme, I am learning in somewhat random order ... if
there is relevant documentation I ought to read, I do know how to
read, so just let me know.

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Manfred Lotz | 20 Nov 16:26 2014

eval question

Hi there,
If I do this in a REPL 

Welcome to Racket v6.1.1.
-> (define p1 '(a . (expt 2 3)))
-> (eval (cdr p1))

it works fine

If I put it in a file:

#lang racket/base
(define p1 '(a . (expt 2 3)))
(eval (cdr p1))

I get this:

expt: unbound identifier;
 also, no #%app syntax transformer is bound
  at: expt
  in: (expt 2 3)
[running body]

What am I doing wrong? Sorry, if this is a stupid question.


(Continue reading)

Alexey Cherkaev | 20 Nov 07:15 2014

SICP picture language: error on affine transformation


I hope the author of the SICP package is on this email list. I have encountered this problem doing affine transformation of the picture:

 (paint ((transform-painter (make-vect 0 0) (make-vect 0.5 0.1) (make-vect 0 0.5)) einstein))

. . ../../../../../../Library/Racket/planet/300/6.1/cache/soegaard/sicp.plt/2/1/prmpnt.scm:376:12: vector-ref: contract violation
  expected: vector?
  given: 0
  argument position: 1st
  other arguments...:

If edge-2 vector is changed to (0 1), there is no problem:

(paint ((transform-painter (make-vect 0 0) (make-vect 0.5 0.1) (make-vect 0 1)) einstein))

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Clemens Novak | 19 Nov 13:00 2014

Source for Racket Guide


I've been reading the Racket Guide and found it really helpful. I'd like 
to be able to read it on my EBook Reader and therefore convert it into 
epub format. How is the guide created: Are the html files in some source 
code repo or only at the website (and I need to download them from there 
and convert into epub)? Or do you generate the html via scribble or some 
other tool (which may allow to generate output as epub)?

Thanks and Regards - Clemens
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Matt Gushee | 19 Nov 12:11 2014

Re: [plt-scheme] Faster CGI

Looks promising. Thank you!

On Wed, Nov 19, 2014 at 3:14 AM, Stephen De Gabrielle
<spdegabrielle@...> wrote:
> Google the original thread for more
> Note racket has changed significantly since 2008!
> ---------- Forwarded message ---------
> From: Eddie Sullivan <eddieSull@...>
> Date: Wed, 10 Dec 2008 at 19:45
> Subject: Re: [plt-scheme] Faster CGI
> To: <plt-scheme@...>
> If anybody's interested, I've attached a simple wrapper for the FastCGI C
> library I hacked up when I was first learning Scheme. As a warning, it's
> probably not the best written code, and it's definitely incomplete, but it
> may be a starting point.
> I originally wanted to code up the FastCGI protocol from scratch, but the
> networking libraries provided with PLT are not low-level enough (I needed
> some way to determine what type of port stdin was, to differentiate between
> CGI and FCGI).
> Anyway, you should be able to run the same code under FastCGI and regular
> CGI. The function "fcgi-loop" takes a no-parameter-function as parameter,
> and calls it repeatedly (for FCGI) or once (for CGI). In the case of FCGI,
> current-input-port, current-output-port, and current-error-port are
> parameterized for the FCGI versions of those ports. It also tries to fake
> out the environment variables, but that part's a little hacky.
> The attached fcgi-cgi.scm shows an example use. It's a (F)CGI script that
> multiplies the two request parameters num1 and num2.
> Hope it helps.
> -Eddie Sullivan
>> From: "Jay McCarthy" <jay.mccarthy@...>
>> Subject: Re: [plt-scheme] Faster CGI
>> Ah, I understand now. Yes, I would recommend writing something like a
>> FastCGI wrapper, I imagine that the protocol is fairly simple, if
>> you'd like me to look it over and give any tips on controlling
>> resources (i.e., with custodians), I'd be happy to.
>> Jay
>> On Mon, Dec 8, 2008 at 8:27 PM, Henk Boom <lunarc.lists@...> wrote:
>> > 2008/12/8 Shriram Krishnamurthi <sk@...>:
>> >> Yes, that's correct.  But the point is that they make it much more
>> >> friendly to use continuations if you so desire (ie, if you haven't
>> >> used the server w/ continuations in a year or two, you may want to
>> >> check whether these additions pass your necessary benchmarking).
>> >
>> > Ok, I see that point. If I am going to use the PLT Web Server then it
>> > makes sense to investigate those options to make using continuations
>> > affordable. The problem I was running into, though, was unaffordable
>> > memory usage even in the absence of continuations.
>> >
>> >    Henk
>> >
>> _________________________________________________
>   For list-related administrative tasks:
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Jens Axel Søgaard | 19 Nov 09:41 2014

Re: FastCGI support?


I think you need:

/Jens Axel

2014-11-19 9:16 GMT+01:00 Matt Gushee <matt <at>>:
> Hello--
> Let me preface this by saying "hi" to the community. This is my first
> post here ... I've been working with Chicken Scheme on and off for 7
> years or so. I tried out PLT Scheme, as it was then called, a couple
> of times in the past, but I felt that it was kind of a toy language.
> Having dug in a bit deeper this time, I see now that I was wrong.
> Anyway, Chicken has a lot of strengths, including a great toolchain
> and a great community, but the libraries often seem like a haphazard
> collection of APIs that don't always work well together. Racket feels
> like much more of a coherent system, and has much better support for
> high-level constructs like signatures and contracts and packages ...
> plus I find the documentation quite thorough and readable, if
> sometimes a bit hard to navigate. And so it looks like I will be using
> Racket to develop a couple of my rather ambitious projects.
> But anyway, for tonight I have one simple question: is there a FastCGI
> module/package for Racket anywhere? I see that Section 20 of the Net
> library docs mention "the FastCGI library." Does that mean something
> that exists, or has existed, or might soon exist, in the Racket world?
> Or does it refer to the C library (libfcgi)?
> I don't imagine it would be terribly hard to write a libfcgi wrapper
> module, but I don't want to reinvent the wheel if there's already
> something out there.
> Thanks for any info!
> --
> Matt Gushee
> ____________________
>   Racket Users list:


Jens Axel Søgaard

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Michael Sperber | 19 Nov 09:29 2014

Call for Participation: BOB 2015 (January 23, Berlin)

Check out the BOB program - many talks and tutorials on functional


			       BOB 2015

	     "What happens if we simply use what's best?"
			   January 23.2015


BOB is the conference for developers, architects and decision-makers
to explore technologies beyond the mainstream in software development,
and to find the best tools available to software developers today.
Our goal is for all participants of BOB to return home with new
insights that enable them to improve their own software development

The program features 14 talks and 8 tutorials on current topics:

The subject range of talks includes functional programming,
microservices, package management, and data management.

The tutorials feature introductions to Erlang, Haskell, Swift, and
ClojureScript, and their applications.

Anil Madhavapeddy will hold the keynote talk - about unikernels and
functional programming.

Registration is open online:

NOTE: The early-bird rates expire on Dec. 19, 2014!

BOB cooperates with the :clojured conference on the following day.
There is a registration discount available for participants of both events.
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