[plt-scheme] Does `(a,b'c) follow r6rs formal grammar?

Plt seems to accept `(a,b'c) as legal r6rs and gives you (a 4 (quote c)) 
assuming b is defined to be 4 as in the previous message. 

On the other hand I have just now built ikarus and see that it rejects the 
expression as having an ill-formed identifier. 

My initial reading of the the standard is that ikarus is right to reject the 
expression and plt is wrong to accept it. 

But I'm kind of a scheme newbie (just trying to be portable) so I'm not sure. 

Jon 


On Sunday 28 June 2009 11:10:19 am Jos Koot wrote: 
> I think 4.2.1 Formal account excludes quotes and commas from identifiers 
> (except when escaped, of course) They are listed as seperate lexemes. 
> Jos 
> 
> ----- Original Message ----- 
> From: "Jon Stenerson" <jonstenerson at comcast.net> 
> To: "Abdulaziz Ghuloum" <aghuloum at gmail.com> 
> Cc: <plt-scheme at list.cs.brown.edu> 
> Sent: Sunday, June 28, 2009 5:29 PM 
> Subject: Re: [plt-scheme] Does `(a,b'c) follow r6rs formal grammar? 
> 
> > Then is it a bug in plt scheme that this is accepted? 
> > 
> > #!r6rs 
> > (import (rnrs)) 
> > (define b 4) 
> > (display `(a,b'c)) 
> > 
> > Using drscheme, the module language, and entering above into definitions 
> > window. 
> > 
> > On Sunday 28 June 2009 02:06:59 am Abdulaziz Ghuloum wrote: 
> >> On Jun 27, 2009, at 8:36 PM, Jon Stenerson wrote: 
> >> > Is the expression `(a,b'c) lexically valid according to r6rs? It says 
> >> > (section 4.2) that identifiers must be terminated by a delimiter or 
> >> > end of 
> >> > input, but this is not true for the identifiers a and b since 
> >> > neither the 
> >> > comma nor quote are listed as delimiters. 
> >> 
> >> You gave the question and the answer. 
> >> 
> >> Aziz,,, 
> > 
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