I think I've successfully written the macro:
(define-syntax (lit-examples stx)
(syntax-case stx ()
[(_ e ...)
#`(begin
(let ([evaluator (make-base-eval)]
[here (quote-source-file #,stx)])
(evaluator `(begin
(dynamic-require '
Given that racket has multiple return values, what sort of issues would
arise if functions were allowed to return no values at all instead of
opting to return the single value void when they have nothing to return? Is
it purely a backwards compatibility thing, or are there more fundamental
problems
On Mon, Jan 05, 2015 at 05:58:31PM -0500, Sean Kanaley wrote:
> I see "void" as a tangible value specifying no information, whereas
> "undefined" is literally no information. So void is more like an empty
> universe and undefined is no universe at all.
Algol 68 had a void value, called 'empty' in
Here’s an alternative solution as a trampolining* macro. The key is to
cooperates with the unit macro’s definition-context handling rather than trying
to duplicate that effort. That’s especially important when dealing with the
unit macro, since it is infeasible to duplicate its handling of unit
MacArthur said so in '41.
On Jan 5, 2015, at 6:39 PM, Robby Findler wrote:
> Oh, it's there. It's just lurking, hiding, biding its time.
>
> All bee bak.
>
> Robby
>
> On Mon, Jan 5, 2015 at 5:13 PM, Matthias Felleisen
> wrote:
>>
>> There is no Undefined. We got rid of it ;-)
>>
>>
>
Oh, it's there. It's just lurking, hiding, biding its time.
All bee bak.
Robby
On Mon, Jan 5, 2015 at 5:13 PM, Matthias Felleisen wrote:
>
> There is no Undefined. We got rid of it ;-)
>
>
> On Jan 5, 2015, at 6:02 PM, Robby Findler wrote:
>
>> And yet, they are both in our current universe.
>
There is no Undefined. We got rid of it ;-)
On Jan 5, 2015, at 6:02 PM, Robby Findler wrote:
> And yet, they are both in our current universe.
>
> On Mon, Jan 5, 2015 at 4:58 PM, Sean Kanaley wrote:
>> I see "void" as a tangible value specifying no information, whereas
>> "undefined" is lite
And yet, they are both in our current universe.
On Mon, Jan 5, 2015 at 4:58 PM, Sean Kanaley wrote:
> I see "void" as a tangible value specifying no information, whereas
> "undefined" is literally no information. So void is more like an empty
> universe and undefined is no universe at all.
>
> On
I see "void" as a tangible value specifying no information, whereas
"undefined" is literally no information. So void is more like an empty
universe and undefined is no universe at all.
On Mon, Jan 5, 2015 at 5:40 PM, Vincent St-Amour
wrote:
> At Mon, 5 Jan 2015 23:20:54 +0100,
> Jos Koot wrote:
At Mon, 5 Jan 2015 23:20:54 +0100,
Jos Koot wrote:
>
> Off topic:
> For me the unanswered question remains:
> Does the vacuum exist or does it not exist?
> I don't know.
Parmenides had something to say on the matter:
http://en.wikipedia.org/wiki/Parmenides#The_Way_of_Truth
Vincent
___
Void is a peculiar thing.
It is used by Racket where no result is ment.
But every expression must have a (multiple) value (if it computes in finite
time)
Because the value of (void) has to be considered to be the absence of a
value,
the repl and the interactions window do not show them. For example
Awesome! Thanks, that works for what I'm doing.
On Mon Jan 05 2015 at 2:47:43 PM Matthew Flatt wrote:
> That turns out to be tricky. I've enclosed an implementation, but it
> works only for units that have no imports.
>
> At Mon, 05 Jan 2015 17:21:37 +, Spencer Florence wrote:
> > What I'm t
That turns out to be tricky. I've enclosed an implementation, but it
works only for units that have no imports.
At Mon, 05 Jan 2015 17:21:37 +, Spencer Florence wrote:
> What I'm trying to do is capture all lifts inside a unit body, instead of
> having them propagating to the top level.
>
> I
On 12/26/2014 10:27 PM, gghh wrote:
Ladies and gentleman, is there is request for video tutorials for Racket
programing language. Cause SICP are not about language it self.
Look the coursera courses:
https://github.com/plt/racket/wiki/Courses-using-Racket
Racket Users
On Sun, Jan 04, 2015 at 11:25:52PM -0500, Alexander D. Knauth wrote:
> will (void) not work?
Only if you know it exists.
Thank you. Every language has a few essential trivia that are hard to
find in the documentation. Eventually you learn how the documentation
is organised and you can find th
What I'm trying to do is capture all lifts inside a unit body, instead of
having them propagating to the top level.
If I understand what you mean by "add internal-definition context to the
bindings listed in `exports`", I can't do that because I need to capture
any lifts inside the unit body, but
I'm not really clear on what you're trying to do. One way to explain
more might be to explain how `test` is meant to differ from `begin`. Or
maybe you can say why it doesn't work to add the internal-definition
context to the bindings listed in `exports` (i.e., to bring everything
into the definitio
Is there any way to have the `test` macro work more like `begin`?
What I am trying to accomplish is something like:
(define-syntax (make-my-unit stx)
(syntax-parse stx
[(e ...)
(with-syntax ([body (local-expand/capture-lifts stx )])
#'(unit (imports ...) (exports ...) bod
I think it's more a question of what a definition context is supposed
to be, rather than how `syntax-local-bind-syntaxes` works.
When you create a new definition context, the context's bindings are
visible only to expressions that are also in that context. The `test`
form here creates a new defini
Progress is a new error! I don't think I understand how
syntax-local-bind-syntaxes is supposed to work. I extended the previous
program:
#lang racket
(require (for-syntax syntax/parse))
(define-syntax (test stx)
(syntax-parse stx
[(_ e)
(define ctx
(if (list? (syntax-local-contex
Anything in particular?
On Mon Jan 05 2015 at 2:45:24 PM gghh wrote:
> Ladies and gentleman, is there is request for video tutorials for Racket
> programing language. Cause SICP are not about language it self.
>
> Regards
>
> Peter Smith.
>
> Racket Users list:
> http://
The error message is intended for "end users" and turns out to be
misleading for the implementor of an internal-definition context. The
documentation for `define-values` has essentially the same problem: it
describes how `define-values` should work in an internal-definition
context, but it doesn't
Hey all,
I'm trying to use 'local-expand', however it seems to think its never in a
definition context. For example:
(require (for-syntax syntax/parse))
(define-syntax (test stx)
(syntax-parse stx
[(_ e)
(define ctx
(if (list? (syntax-local-context))
(cons (gensym) (s
Ladies and gentleman, is there is request for video tutorials for Racket
programing language. Cause SICP are not about language it self.
Regards
Peter Smith.
Racket Users list:
http://lists.racket-lang.org/users
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