[R6RS] fixnum operators and overflow detection

[William D Clinger]

> > I'd like to see both the first and the third in R6RS. =20
> 
> I'll just point out that the current draft already has the second
> option (fixnum operations with carry).

It has fx+/carry, fx-/carry, and fx*/carry, but doesn't
have /carry versions of the shift operations.  I'd just
as soon continue to leave those out.

If the editors agree with

1. adding the third option (fixnum operations that raise an
exception on overflow), and
2. renaming the SRFI's fixnum operations to fixnum+, fixnum-,
fixnum-bitwise-and etc, and
3. adding operations fx+, fx-, etc that raise an exception
on overflow,

then

4. should I go ahead and perform that surgery on the SRFI
and on its reference implementation?

Will