gmane.comp.lang.racket.user

Redex hackfest

Alex Marquez — 2013-05-23T17:43:18

Several of us at the NEU Programming Research Laboratory are interested in improving Redex and will be having a hackfest to do so, scheduled for sometime in the first week of June.

We invite whomever would like to join to express their interest and availability, as that will influence the exact schedule.  It is not required to be physically at NEU; rather, one may simply take the opportunity to hack remotely and communicate via e-mail or IRC, taking advantage of the collective focus on Redex for the time.

Our high-level, provisional "wishlist" for changes to Redex is available at:
https://github.com/plt/racket/wiki/Redex-Features

Please feel free to comment on these features or add to them as you see fit.  Until the hackfest, we will be using this thread to discuss logistics and these features.


Alex Marquez
NEU PRL
____________________
  Racket Users list:
  http://lists.racket-lang.org/users

Re: Using `dynamic-require` for optional user-supplied "template" code?

Robby Findler — 2013-05-23T19:38:59

Every function is jitted the first time it is called if you're running on a
platform that the JIT supports (currently x86 and ARM).

Robby


On Thu, May 23, 2013 at 1:25 PM, Greg Hendershott <greghendershott-Re5JQEeQqe8AvxtiuMwx3w< at >public.gmane.org

____________________
  Racket Users list:
  http://lists.racket-lang.org/users

Re: Why functional?

Greg Hendershott — 2013-05-23T18:48:37

To me, that's the crux. The problem isn't assignment, it's REassignment.

Saying that "X is 1" is fine. The problem is later saying, yeah
actually, X isn't 1 anymore. What, you didn't get the memo?

Even a pure functional program is constantly writing to memory, or it
wouldn't be accomplishing anything. The "state" of interest here isn't
RAM, it's your names for things in RAM.

Also, any practical system will be non-functional at its "edges": At
some point, it has to earn its living by doing I/O of some sort.

My word cloud also includes:

WORM: Write Once, Read Many.

CR_D: CRUD with Create, Read, and Delete, but without the Update.

POST, GET, DELETE: HTTP without the P verbs. No PUT. _Definitely_ no PATCH. ;)

Finally I think it's important to walk the talk. My understanding of
functional programming, however poor, is itself purely functional.
Nothing anyone says will change it. :p
____________________
  Racket Users list:
  http://lists.racket-lang.org/users

Re: Using `dynamic-require` for optional user-supplied"template" code?

Greg Hendershott — 2013-05-23T18:25:11

p.s.


That question had mixed polarities. :)  I should have written, I think
the answer is No there's no big performance hit, and Yes it gets
JIT-ed.

On Thu, May 23, 2013 at 2:22 PM, Greg Hendershott
<greghendershott-Re5JQEeQqe8AvxtiuMwx3w< at >public.gmane.org> wrote:
____________________
  Racket Users list:
  http://lists.racket-lang.org/users

Using `dynamic-require` for optional user-supplied"template" code?

Greg Hendershott — 2013-05-23T18:22:08

I've never had a reason to use `dynamic-require`, but now I think I do.

For my Frog static blog generator, I'd like to provide a light
"template" feature, where the user can override the default layout of
the main container <div> in the page.

I have an existing function that returns an xexpr for this. So my idea
is to let the user optionally supply a `template.rkt` file that
`provide`s a function named (say) `container` that returns (listof
xexpr?).

So I think what I want to do is something like this:

(define (container-proc)
  (define p (build-path (src-path) "template.rkt"))
  (cond [(file-exists? p)
         (dynamic-require p
                          'container
                          (thunk default-container))]
        [else default-container]))

The built-in `default-container` looks something like this:

(define (default-container bootstrap-row-class ;"row" or "row-fluid"
                           bodies              ;listof xexpr?: main content
                           tocs                ;

link errors on 64bit

David Griffiths — 2013-05-23T13:43:18

Hi all,

I've been getting a problem for some time building against the racket
ubuntu packages on 64 bit:

/usr/bin/ld: /usr/lib/libracket3m.a(salloc.o): relocation
R_X86_64_TPOFF32 against `scheme_thread_locals' can not be used when
making a shared object; recompile with -fPIC

Any chance this can be resolved?

cheers,

dave
____________________
  Racket Users list:
  http://lists.racket-lang.org/users

Re: Why functional?

George Rudolph — 2013-05-23T11:40:57


Lawrence Bottorff <borgauf< at >...> writes:

star (favorite question) -- although only one response. I'd really like to 
clear these issues up in my mind. Here goes:
explanations, but I'm still not able to understand the mathematical 
connection between "changing state" and "not changing state" as it pertains 
to our functional programming versus non-FP debate. I understand the basic 
argument goes back to the pure math definition of a function, whereby a 
function maps a domain member to only one range member. This is subsequently 
compared to when a computer code function is given certain input, it will 
always produce the same output, i.e., not vary from use to use, i.e.i.e., 
the function's state, bzw. its domain to range mapping behavior, will not 
change.

------------------------------
Lawrence,
Take a different perspective entirely.  Forget the mathematical and 
theoretical
stuff for the moment.  Think about sources for bugs in imperative, 
procedural or OO programming,
when left up to a programmer to

Boston Lisp Meeting 2013-05-23T18:30 THIS THURSDAY! Faré: Tutorial on ASDF3

Francois-Rene Rideau — 2013-05-23T07:17:57

Boston Lisp Meeting 2013-05-23T18:30 -- Faré: Tutorial on ASDF3

When? TONIGHT, Thursday May 23rd 2013 at 6:30pm.

Where? MIT 32-D463 (Star conference room at the Stata Center).
http://whereis.mit.edu/?go=3D32

Who Speaks? François-René Rideau will give a Tutorial on ASDF3

I'm sorry about the short notice on this one;
communications problems of all kinds have been gumming up the works.
Please feel free to spread the word about the meeting
via whatever mechanisms are available to you.

Talk details follow. I hope to see you all there!

Title: "ASDF 3, or lessons in building portable Common Lisp programs"

Summary:
"ASDF (Another System Definition Facility) has been the de facto standard
Common Lisp build system for over ten years.
I recently rewrote it completely, several times,
all along mostly preserving backwards compatibility.
The latest incarnation, ASDF 3, in addition
to fixing deep design bugs older than ASDF itself,
also includes extensive portability library, UIOP,
not to be confused with an exi

Re: gui application needs to perform operation upon closing of a window

Robby Findler — 2013-05-23T02:32:00

Thanks, I've fixed those docs.

Robby


On Wed, May 22, 2013 at 9:06 PM, Stephen Chang <stchang-1vnkWVZi4QaVc3sceRu5cw< at >public.gmane.org> wrote:

____________________
  Racket Users list:
  http://lists.racket-lang.org/users

Inlining HTML in Scribble

Rommel Martinez — 2013-05-23T02:31:05

While searching for ways on how to inline HTML code, I stumbled across
https://groups.google.com/forum/?fromgroups#!topic/plt-scheme/HLSSF6-tKHQ.
However, I can't seem to follow the chain of procedures to create the
equivalent
for inserting arbitrary HTML.

For example, I'd like for example to have something like:

    < at >html|{<p align="justify"><a href="http://google.com">foo</a> bar</p>}|

that will insert the above snippet to the current location, as is.

Re: gui application needs to perform operation upon closing of a window

Stephen Chang — 2013-05-23T02:06:14

Ah ok I see now. I didn't look hard enough.

I saw the "frame%" so I was clicking around here:
http://docs.racket-lang.org/tools/drracket_unit.html?q=on-close#%28meth._%28%28%28lib._drracket%2Ftool-lib..rkt%29._drracket~3aunit~3aframe~25%29._on-close%29%29

On Wed, May 22, 2013 at 7:59 PM, Matthias Felleisen
<matthias< at >ccs.neu.edu> wrote:

____________________
  Racket Users list:
  http://lists.racket-lang.org/users

Re: gui application needs to perform operation uponclosing of a window

Matthias Felleisen — 2013-05-22T23:59:23

From the docs: 

"
method
  (send a-top-level-window on-close) → void?

Refine this method with augment.
...
"



On May 22, 2013, at 7:14 PM, Stephen Chang wrote:



____________________
  Racket Users list:
  http://lists.racket-lang.org/users

Re: gui application needs to perform operation upon closing of a window

Stephen Chang — 2013-05-22T23:14:43

I was about to reply with the same answer as Matthias, but with
define/override instead of define/augment, but I kept getting an
error. Does it say anywhere in the docs whether a method is declared
using pubment or public? I couldnt find it.

On Wed, May 22, 2013 at 7:06 PM, Matthias Felleisen
<matthias-1vnkWVZi4QaVc3sceRu5cw< at >public.gmane.org> wrote:
____________________
  Racket Users list:
  http://lists.racket-lang.org/users

Re: gui application needs to perform operation uponclosing of a window

Matthias Felleisen — 2013-05-22T23:06:18

Here we go: 

#lang racket/gui

(define my-frame%
  (class frame%
    (super-new)
    (define/augment (on-close)
      (displayln "closing now"))))

(define frame
  (new my-frame% [label "on closing"][width 300][height 200]))

(send frame show #t)



On May 22, 2013, at 6:55 PM, Zelah Hutchinson wrote:



____________________
  Racket Users list:
  http://lists.racket-lang.org/users

gui application needs to perform operation upon closing of a window

Zelah Hutchinson — 2013-05-22T22:55:43

From the documentation I gather that I need to augment the on-close method. I do not understand how to do this. Can someone show me a tiny example of how to perform an operation when a window is closed? Thank you.

____________________________________________________________
FREE 3D MARINE AQUARIUM SCREENSAVER - Watch dolphins, sharks & orcas on your desktop!
Check it out at http://www.inbox.com/marineaquarium



____________________
  Racket Users list:
  http://lists.racket-lang.org/users

Planet2 Corrupted PNR Entry

Ray Racine — 2013-05-22T22:02:51

Seems I managed to slip a bad source URL into my first Planet2 test
submittal.  Reasonably sure I have a typo in the Url to github resulting in
an exception on attempting to determine checksum.

If someone could blow away the 'grip' package entry I'd be appreciative.

https://pkg.racket-lang.org/info/grip

Ray
____________________
  Racket Users list:
  http://lists.racket-lang.org/users

Re: Parens/string quotes automatic behavior

Laurent — 2013-05-22T21:16:52

Thanks!


On Wed, May 22, 2013 at 11:05 PM, Nadeem Abdul Hamid <nadeem-HInyCGIudOg< at >public.gmane.org> wrote:

____________________
  Racket Users list:
  http://lists.racket-lang.org/users

Re: Parens/string quotes automatic behavior

Nadeem Abdul Hamid — 2013-05-22T21:05:05

Ok ok. :-) I will try to work on it in the next day or so if no one else
gets to it first.
--- nadeem

On Wednesday, May 22, 2013, Laurent wrote:

Re: Typed Racket has finally arrived!

Eli Barzilay — 2013-05-22T18:24:22

That would be some way to communicate type information to the macro
expansion.  What I'm talking about is much simpler: just macro-expand
the types like all other syntax, which gets you something that is
"only" as strong as Racket macros.  (Later on, it can be extended in a
compatible way to know about types via something like syntax
properties, or a syntax-time parameter.)

Re: Why functional?

Matthias Felleisen — 2013-05-22T17:57:29

Hi Lawrence, 

your little essay is fascinating and intriguing from the perspective of 'ideals' -- as in ideal FP and ideal OOP etc. I am sure 'philosophers' of programming languages with a sufficient technical understanding of your example could have a field day. 

The sentence concerning 'elisp' in your last paragraph worries me, however. Elisp -- like any Lisp, say Common Lisp or Racket -- is not a functional language in the purist's point of view. It supports direct, uncontrolled, and full-powered effects wherever and whenever a programmer wants it. Meaning, looking at Lisp code will not really help you tease out answers to your deep questions. Indeed, if we were to answer these questions here,  I am sure we would soon get into the fine details of when to use side-effects in Racket. 

Let me suggest an alternative then. Haskell is the language that most people consider the purest functional language of all. It does not even allow real exceptions to ensure that programs have certain mathematical properti

Re: Why functional?

Nick Shelley — 2013-05-22T17:57:34

I'm sure you'll get more sophisticated responses soon, but this blog post
by John Carmack helped me understand the ideas and tradeoffs a bit. I'm not
sure everything in there is 100% correct or that I agree with everything,
but I think it provides a pretty good overview.

http://www.altdevblogaday.com/2012/04/26/functional-programming-in-c/

I think Neil Toronto originally posted this to the list a while back, which
is how I came across it.


On Wed, May 22, 2013 at 10:24 AM, Lawrence Bottorff <borgauf-Re5JQEeQqe8AvxtiuMwx3w< at >public.gmane.org>wrote:

____________________
  Racket Users list:
  http://lists.racket-lang.org/users