[R6RS] How to make -> a valid identifier [was: 3 things we may want to vote on]

Marc Feeley feeley
Wed Jun 8 11:18:10 EDT 2005

On 8-Jun-05, at 10:10 AM, dyb at cs.indiana.edu wrote:

>> At Wed, 08 Jun 2005 09:12:00 +0200, Michael Sperber wrote:
>>> ... and then saying that any <token> that also matches <number> is
>>> indeed a number, and the rest are identifiers.
>> This is how MzScheme defines symbols, too.
> Chez Scheme as well.  If I'm not mistaken, the same is also true for
> Common Lisp.  I also recall some RnRS authors being adamantly  
> opposed to
> such a definition, and it does lead to some poor feedback when someone
> tries to type in a complicated numeric literal and barely misses,  
> like:
>  +1.3482767e21 at 2.22001e26i
> Kent
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Gambit does as well (i.e. symbol = not a number and not a keyword).   
The other problem with defining it this way in the R6RS is that  
future revisions of the standard may have important backward  
compatibility problems if the syntax of numbers is changed.  So  
although "symbol = not a number and not a keyword" is fine for an  
implementation of Scheme, it is not OK for the specification of Scheme.


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