[racket] Onlisp's condlet macro in Racket

I meant to rewrite with syntax-parse before emailing out to show error checking. Out of time. 


On Jan 2, 2013, at 11:37 AM, Robby Findler wrote:

> 
> 
> 
> On Wed, Jan 2, 2013 at 10:33 AM, Matthias Felleisen <matthias at ccs.neu.edu> wrote:
> 
> Sean, it took me a while to figure out condlet but here is how a Racketeer would write this (questionable) macro: 
> 
> (define-syntax (condlet stx)
>   (syntax-case stx ()
>     [(condlet ((c (x e) ...) ...) body ...)
>      #'(cond
>          [c (let* ((x '()) ... ...)
>               (let ((x e) ...)
>                 body ...))] 
>           ...)]))
> 
> As Stephan points out, a let* suffices here because it simply doesn't matter because it simply doesn't matter which x binding body ... sees. 
> 
> 
> This could be define-syntax-rule, no (since there's no error checking)?
> 
> Robby
> 

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