[racket] macro question

On 10/02/2014 09:19 PM, Kevin Forchione wrote:
> Hi guys,
> Why does this appear to work? I assume it’s not a recommended approach.
>
> #lang racket
>
> (require (for-syntax syntax/parse))
>
> (define-syntax (mylet stx)
>    (let ([val (syntax-case stx ()
>                 [(_ x) #'x]
>                 [(_ x xs ...) #'(cons x (mylet xs ...))])])
>      val))
>
> (mylet 1 2 3) => ‘(1 2 3)

It doesn't return '(1 2 3); it returns '(1 2 . 3).

Other than that, the let is unnecessary, but it's just a straightforward 
recursive macro.

Maybe the answer to your question is that syntax-case is nothing 
special; it's basically a version of match specialized to dealing with 
syntax objects. You can use it inside of other expressions. See 
http://www.greghendershott.com/fear-of-macros/ for an explanation of how 
not-special syntax-case is.

Ryan