1. You should make your macro robust and deal with fewer than two elements in
your uses.
2. Here is the same idea w/ syntax-rules:
#lang racket
(define-syntax quote-even
(syntax-rules ()
[(_) '()]
[(_ zero) (list 'zero)]
[(_ zero one two ...) (list* 'zero one (quote-even two .
Great, thanks!
On 01/26/2015 10:57 PM, Alexander D. Knauth wrote:
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 (?@ 'a
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
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
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