Why tuple with one item is no tuple

[Jeremy Bowers]

On Wed, 16 Mar 2005 17:28:51 -0800, James Stroud wrote:

> On Wednesday 16 March 2005 04:45 pm, Robert Kern wrote:
>> > This would be very unambiguous.
>>
>> Not entirely.
>>
>> > Then, the purity would manifest itself the naked comma being an empty
>> > tuple. Think about the zen of:
>> >
>> >    ,
>>
>> Is that a tuple or grit on my monitor?  :-)
> 
> OK, OK, I'll give up on the commas. Maybe we should just use dollar signs :?

No, using symbols like that is bad. Clearly we need a new parser constant,
THE_ZERO_LENGTH_EMPTY_TUPLE. 

We will, of course, have to forbid assigning any other name to that
constant (more language changes) so that people don't start creating their
own inconsistent name... *especially* shorter ones.