Re: Implementing an "in" operator

Ed Davis <ed_davis2@yahoo.com> wrote:
>Any ideas on how one would implement an "in" operator?
>
>As in (no pun intended):
>
> if (a in b,c,d..e)
> statements;
>
>translates to:
>
> if (a == b or a == c or (a >= d and a <=e))
> statements;


I'd be inclined to make 'b,c,d..e' be a literal of some appripriate
type and make 'in' a binary operator taking an object of type T as its
left operand and an object of type 'list of T', 'set of T' or suchlike
as it right operanad. This would also allow constructs like:


x = <nasty complex range specification>
if (a in x) {
...
} else if (b in x) {
...
}


making it a lot clearer that the same list of ranges is used twice.

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