[SCL] ellipsis for seqvar notation

[Mark Stickel]

Upon further reflection, I recommend seqvar be defined by
  seqvar = {char} "..." {char}

This allows "x1...xn" to be a seqvar, for example.

Mark

Mark Stickel wrote:

> 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
>>
>>
>
>
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