ways to declare empty set variable

[bearophileHUGS at lycos.com]

Ben Finney:
> Generator literals do not require the
> parens at all. However, the syntax of where the generator literal
> *appears* can make it necessary to explicitly group the expression
> using parens.

Have you taken a look at Boo?
In Python this isn't possible:
s = char for char in string.digits
You need ( ) there, while in Boo they aren't necessary there.

Bye,
bearophile