[r6rs-discuss] Date and time arithmetic library proposal for R7RS large Scheme

[John Cowan]

Marc Feeley scripsit:

> Please don't count time using milliseconds.  It clutters my brain to
> have to remember a different unit of time than plain seconds.

And yet the SI unit of mass is the kilogram.  But I'll think about that.

> Moreover, the choice of milliseconds, rather than microseconds or
> nanoseconds is purely an artifact of the current speed of computers.

I think it's more about range vs. precision issues.

> Integers shouldn't be used for measuring time points because
> applications need different resolutions.

That's a strong point for requiring floats, but ...

> With a 64 bit float, you can represent a time interval of up to
> 3 months with a nanosecond resolution, and up to 266 years with a
> microsecond resolution.  I don't see any practical reason for wanting
> more than this.

In the new all-64-bit world, 60-bit fixnums will have more range than
53-bit flonums, and they will not need to be boxed, which makes them
faster to fling around.

-- 
"Well, I'm back."  --Sam        John Cowan <cowan at ccil.org>