syntax/parse can do that:
#lang racket
(require (for-syntax racket/base syntax/parse
syntax/parse/experimental/template))
(define-syntax quote-even
(syntax-parser
[(quote-even (~seq att val) ...)
(template (list (?@ 'att val) ...))]))
(quote-even a 1 b 2) ; '(a 1 b 2)
On Jan 26, 2015, at 4:48 PM, Peter Samarin <petrsama...@gmail.com> wrote:
> Hello all,
>
> I want to quote every even and evaluate every odd variable of the input and
> assemble everything in a list.
> So I wrote the following macro to do it:
>
> (define-syntax quote-even
> (syntax-rules ()
> [(quote-even att val ...)
> (list 'att val ...)]))
>
> But in the resulting list, only the very first attribute is quoted:
>
> (syntax->datum
> (expand-once
> '(quote-even a 10 b 20 c 30)))
>
> > (list 'a 10 b 20 c 30)
>
> (quote-even a 10 b 20 c 30)
> > b: undefined;
>
>
> Is there a way to do do it?
>
> Cheers,
> Peter Samarin
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