Re: [racket] macro expansion function in Scheme

On Jul 12, 2011, at 7:08 PM, Bas Steunebrink wrote: > Any anomalies (such as "lambda:2" -> "lambda") are easily fixed. :-) That's not an anomaly but an annotation from the expander that may matter (as in, use a different lambda here). But I assume you know that. Glad we could help -- Matthia

Re: [racket] macro expansion function in Scheme

Excellent idea! I looked at the source code of macro-debugger but there was quite an intimidating amount of it. :-s So I took the ugliest but fastest path: simply catch the textual output of the expand/step-text function and use Racket's reader to get the result of the last step as a datum (I k

Re: [racket] What are the roles for teachpacks these days?

On Tue, Jul 12, 2011 at 3:29 PM, Danny Yoo wrote: >> On Tue, Jul 12, 2011 at 3:54 PM, Robby Findler >> wrote: >>> I don't have any plans to make the menu-based teachpacks work with >>> #lang languages. They all have require-based interfaces, tho (eg >>> (require 2htdp/image) and (require htdp/ima

Re: [racket] What are the roles for teachpacks these days?

> On Tue, Jul 12, 2011 at 3:54 PM, Robby Findler > wrote: >> I don't have any plans to make the menu-based teachpacks work with >> #lang languages. They all have require-based interfaces, tho (eg >> (require 2htdp/image) and (require htdp/image)); are those not >> sufficient somehow? No, using r

Re: [racket] What are the roles for teachpacks these days?

Yeah. Could we just have the Language menu and Teachpacks fade away? I've been bitten so many times by the hidden stuff that I think it's easier to have students explicitly write #lang htdp/bsl (require 2htdp/image) at the top of files. I'd prefer something like #lang beginner, but I don't reall

Re: [racket] What are the roles for teachpacks these days?

I don't have any plans to make the menu-based teachpacks work with #lang languages. They all have require-based interfaces, tho (eg (require 2htdp/image) and (require htdp/image)); are those not sufficient somehow? Robby On Tue, Jul 12, 2011 at 12:35 PM, Danny Yoo wrote: > So let's say that I'm

[racket] What are the roles for teachpacks these days?

So let's say that I'm designing a new #lang-implemented language. I'd love to automatically work with teachpacks and other external modules. So I can get require-like functionality with my language, and that seems to work ok. But when I click on Language/Add Teachpack, DrRacket responds by sayin

Re: [racket] Tools for new languages

As much as I welcome the idea of another experimental language in DrRacket, I need to warn you of the potential dangers in your particular case. What I mean specifically with 'your' case is the choice of 'ugly' syntax for Grace. You seem to be determined to use a non-S-expression language (whi

Re: [racket] Tools for new languages

On Jul 12, 2011, at 9:02 AM, Sam Tobin-Hochstadt wrote: > An excellent reference for this (which is also OO in a > non-racket/class like way) is Dave Herman's javascript.plt Planet > package: > http://planet.racket-lang.org/display.ss?package=javascript.plt&owner=dherman intrigued, I opened 5.1.1

Re: [racket] Amazon Linux update causes `require' in 5.1.1 to hang indefinitely?

> I'd guess it's the what the jit is compiling to as opposed to the > memory manipulations themselves that is causing it to spin. Ah, I see what you mean. In fact that's evident from the "context" for the error message, which differs for JIT on or off: ===[ JIT off ]==

Re: [racket] Amazon Linux update causes `require' in 5.1.1 to hang indefinitely?

On Mon, Jul 11, 2011 at 10:46 PM, Eli Barzilay wrote: > An hour and a half ago, Greg Hendershott wrote: > > I've discovered that the problem does NOT happen if I start racket > > with -j a.k.a. --no-jit. > > > > ? > > It might be one of these things that prevent data execution. I helped debug t

Re: [racket] Amazon Linux update causes `require' in 5.1.1 to hang indefinitely?

> It might be one of these things that prevent data execution. With the > jit on, Racket is basically throwing some numbers into memory and then > executes them -- which is a power that some people don't like. It > (Racket) does do the right thing an marks those memory pages as > executable, but

[racket] Lambda keyboard shortcut

Hi all, In DrRacket 5.0.1 in OS X I can press "Cmd + (key left to the non-numeric pad 1)" to write λ. However in DrRacket 5.1.1 I need to press "Cmd + Option/Alt + the other key". In both versions, the Insert Menu shows that to write a lambda you press Cmd + \. is it a bug in previous versions? c

Re: [racket] help: how to make eval see local bindings?

On Tue, Jul 12, 2011 at 4:36 PM, maurizio.giorda wrote: Hi Matthias, ... I will play with your example (it is better than all the words I spent with my looong

Re: [racket] macro expansion function in Scheme

I think you want to use `expand' and `eval-syntax', and avoid `syntax->datum' entirely. On Tue, Jul 12, 2011 at 10:30 AM, Bas Steunebrink wrote: > Thanks Matthias and Eli, I understand what expand does and that > syntax->datum throws away too much (by design). Still my question remains of > how t

Re: [racket] macro expansion function in Scheme

Since Ryan's stepper does that and renders the expression for you, I suspect he could supply something close to syntax->datum*. On Jul 12, 2011, at 10:30 AM, Bas Steunebrink wrote: > Thanks Matthias and Eli, I understand what expand does and that syntax->datum > throws away too muc

Re: [racket] macro expansion function in Scheme

Thanks Matthias and Eli, I understand what expand does and that syntax->datum throws away too much (by design). Still my question remains of how to obtain a datum that is equivalent to a given quoted expression (when eval'ed) but with all macros expanded (generating fresh symbols where necessar

Re: [racket] macro expansion function in Scheme

On Jul 12, 2011, at 10:16 AM, Eli Barzilay wrote: > 8 minutes ago, Matthias Felleisen wrote: >> >> The following experiment produces a bit more insight: >> >>> (((eval (expand '(m y))) #t) #f) >> #t >> >> The result of expand compiles to the correct closure. >> >> So the docs for syntax->d

Re: [racket] macro expansion function in Scheme

8 minutes ago, Matthias Felleisen wrote: > > The following experiment produces a bit more insight: > > > (((eval (expand '(m y))) #t) #f) > #t > > The result of expand compiles to the correct closure. > > So the docs for syntax->datum are dead serious when they say that it > "returns a datum

Re: [racket] help: how to make eval see local bindings?

On Tue, Jul 12, 2011 at 4:36 PM, maurizio.giorda wrote: > ** > Hi Matthias, > > ... I will play with your example (it is better than all the words I spent > with my looong > description: > > Here is what I meant: > > #lang racket > > (define-syntax-rule > (mm x) > (lambda (w) (displayln `(,

Re: [racket] macro expansion function in Scheme

On Jul 12, 2011, at 9:32 AM, Bas Steunebrink wrote: > Wow, it was right under my nose! :-) Thanks! > > So I've been playing around with expand but it does not always return what > I'd expect, particularly with making fresh variables. For example: > > > (define-syntax m >(syntax-rules () >

Re: [racket] help: how to make eval see local bindings?

Hi Matthias, ... I will play with your example (it is better than all the words I spent with my looong description: Here is what I meant:  #lang racket (define-syntax-rule

Re: [racket] macro expansion function in Scheme

Wow, it was right under my nose! :-) Thanks! So I've been playing around with expand but it does not always return what I'd expect, particularly with making fresh variables. For example: > (define-syntax m (syntax-rules () ((_ x) (lambda (x) (lambda (y) x) > (((m y) #t) #f

Re: [racket] help: how to make eval see local bindings?

On Jul 12, 2011, at 6:41 AM, Maurizio Giordano wrote: > Hi Matthias, hi schemers, > > 2011/7/11 Matthias Felleisen > > Now I don't understand at all why you want to use eval in the macro. > If the right-hand side just returned the lambda that you have there, > it would automatically capture th

Re: [racket] Tools for new languages

On Tue, Jul 12, 2011 at 8:37 AM, Robby Findler wrote: > Probably the right path is to write a parser (using the parser > collection) that essentially just turns everything into a fully > parenthesized language and then use the macro system from there to > compile into some variant of Racket (you c

Re: [racket] Tools for new languages

In the Racket world, OO tends to be a library; it doesn't have to be baked in a low-level thanks to the macro system (specifically the racket/class system is probably the most widely used oo system in Racket). Probably the right path is to write a parser (using the parser collection) that essentia

Re: [racket] macro expansion function in Scheme

On Tue, Jul 12, 2011 at 13:49, Bas Steunebrink wrote: > Ciao a tutti, > > I'm looking for a Scheme function that can perform macro expansion on a > quoted expression. I bet someone has implemented such a thing before, but I > can't find it. Maybe someone can point me in the right direction? http:

[racket] Tools for new languages

Hey folks, I'm working with a project that's designing a new pedagogical object-oriented language called Grace . My job is to find a good IDE, and so far, DrRacket has looked like a good choice. I've been slowly figuring out how to get a Grace parser written in Racket, bu

[racket] macro expansion function in Scheme

Ciao a tutti, I'm looking for a Scheme function that can perform macro expansion on a quoted expression. I bet someone has implemented such a thing before, but I can't find it. Maybe someone can point me in the right direction? For example, I'm looking for something that works along the follo

Re: [racket] help: how to make eval see local bindings?

Hi Matthias, hi schemers, 2011/7/11 Matthias Felleisen > > Now I don't understand at all why you want to use eval in the macro. > If the right-hand side just returned the lambda that you have there, > it would automatically capture the variables in the context of the > gama rule. > > > Have you

[racket] rash (Was:interactive hack)

Eli Barzilay wrote at 07/11/2011 11:39 PM: Yesterday, D Herring wrote: rash: racket shell This one should be used by an actual shell-thing. Some student should shamelessly steal "scsh" shell, retrofitting Racket, renaming "rash". -- http://www.neilvandyke.org/ __

[racket] suspicious timing in running test program

Ciao, I am using "plt-r6rs" from Racket 5.1.1 (compiled with default options) on a i686-pc-linux-gnu; when running the tests ofNausicaa/Scheme[1] revision 0.2d10, with precompiled libraries, I get some suspicious timing. First I run a test file[2] which uses some technique