[racket-dev] shared no longer works on cons?!?

On 10/20/2011 09:24 PM, Robby Findler wrote:
> On Thu, Oct 20, 2011 at 10:11 PM, Ryan Culpepper<ryan at cs.utah.edu>  wrote:
>> Looks like it works in 5.0.2 (November 2010) but fails in 5.1 (February
>> 2011).
>
> You're talking about in the teaching languages, right?

Right, I was talking about just the teaching languages.

 > In #lang
> racket, I see the first-produces-error behavior back to 5.0:
>
> [robby at penghu] /Applications/Racket v5.0.2/bin$ ./racket
> Welcome to Racket v5.0.2.
>>   (first (shared ((x (cons 1 x))) x))
> first: expected argument of type<non-empty list>; given #0='(1 . #0#)
>
> At least for the racket language, this seems to go back at least as far as 5.0:
>
> [robby at penghu] /Applications$ ./Racket\ v5.0/bin/racket
> Welcome to Racket v5.0.
>> (first (shared ((x (cons 1 x))) x))
> first: expected argument of type<non-empty list>; given #0='(1 . #0#)

This behavior in the racket/scheme languages goes back to at least PLT 
Scheme 4.2, and probably as long as scheme/list has existed.

Ryan