[SCL] ellipsis for seqvar notation

[Mark Stickel]

Pat Hayes also mentioned the possibility of "z..." instead of "...z".
Personally, I don't find one much more intuitive than the other,
but if some do, I don't see any reason in priniciple that seqvars
have to be marked by an initial "..." (or "@") versus a final one.

Moreover, to accomodate all tastes, we could define seqvar by
  seqvar = {char} "..." | "..." {char};
or even
  seqvar = {char} "..." {char};

Mark

Pat Hayes wrote:

> Comments requested on the following proposed change.
>
> Mark Stickel suggests that we adopt the ellipsis (three dots, ...) as 
> the distinctive prefix for a seqvar, rather than the @ symbol.  This 
> is quite attractive, as it more directly conveys the sense of 'and so 
> on' that is captured by the use of seqvars, and it frees up a symbol 
> which already has other uses in some contexts, most notably in email 
> address formats.  So
>
> (R x y @z)
>
> becomes
>
> (R x y ...z)
>
> Mark also suggests that the syntax be allowed to use just the ellipsis 
> as a seqvar, so that unless one uses two in a single expression, there 
> would be no need to decorate the ellipsis with any further lexical 
> stuff. The result is even more elegant:
>
> (R x y ...)
>
> Any objections?? If I don't hear any I will make this change to the 
> core syntax.
>
> Pat
>
>