For more explanation about my goal, here is "wrong" version :

#lang racket/gui

(define frame (new frame% [label "test"]))
(send frame show #t)

(define-syntax (mk-widget stx)
  (syntax-case stx ()
    [(_ (list (cons (datum->syntax k) v) ...))
     #'(new button% [k v] ...)]))

; Work, but not my end goal
(mk-widget (list (cons 'label "init")
                 (cons 'parent frame)
                 (cons 'stretchable-width #t)))

; My end goal
; (define d (list (cons 'label "init") (cons 'parent frame)))
; (mk-widget d)

It works in the first case because I think that the variable is never
My goal is the second case, where it is given by a variable. But I hope
this can help a little. Is there a way to have a `list->syntax`?

Thank you for reading,

Denis Michiels <dmichi...@mailoo.org> writes:

> Hello,
> thank you for this start of response, but my goal is to be more general,
> and not to make specific action (here, the label must be the first in
> the list, ...).
> In fact, I want to "rewrite" the `new` function, but only with raw
> data-type (like list and cons). Or at least, something that transform
> raw data-type to the `new` function.
> And I hope it could be used for any class (at least for GUI class). Is
> that possible or I'm trying to do something that is not the goal of
> macro in Racket?
> kind regards,
> Denis
> Matthias Felleisen <matth...@felleisen.org> writes:
>>> On May 14, 2018, at 6:55 AM, Denis Michiels <dmichi...@mailoo.org> wrote:
>>> Hello,
>>> I'm trying to build a macro to be able to do :
>>> ```
>>> (define data (list (cons 'label "My button")
>>>                   (cons 'stretchable-width #t)))
>>> (my-macro button% data)
>>> ```
>>> to be translated in  :
>>> ```
>>> (new button% [label "My button"] [stretchable-width #t])
>>> ```
>>> (I take gui example, and incomplete (like no frame) but it is to show my
>>> goal)
>>> Unfortunately, I didn't manage well macro in Racket...
>>> Can someone help me, or have a hint how to manage this macro?
>> #lang racket/gui
>> (define data '((label "My button") (stretchable-width #t)))
>> (define-syntax (mk-but stx)
>>   (syntax-case stx ()
>>     [(_ data)
>>      #'(let ()
>>          (match-define (cons label others) data)
>>          (define button (make-object button% (second label) frame))
>>          (for ((o others))
>>            (match-define (list m val) o)
>>            (dynamic-send button m val)))]))
>> (define frame (new frame% [label "test"]))
>> (mk-but data)
>> (send frame show #t)

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