Re: Support for sub-second time in decoded time

[Stefan Monnier <monnier@iro.umontreal.ca>]

Lars Ingebrigtsen [2019-07-29 16:12:34] wrote:

> Stefan Monnier <monnier@iro.umontreal.ca> writes:
>
>>> `current-time' returns its data as (HIGH LOW USEC PSEC), but now that we
>>> have bignum support, perhaps we don't need to do it this way.  What
>>> about just having a field in decoded times that's the fraction of a
>>> second?  So 34.5603 seconds would be represented as
>>>
>>> (34 ... 5603)
>>
>> `encode-time` uses a fraction-representation (NOM . DENOM), which is
>> probably easier to manipulate.
>
> You mean internally?

No, as yet-another format.

> It doesn't seem to be mentioned in the doc string,
> but it's an entire essay now...

It's here:

    If FORM is a positive integer, the time is returned as a pair of
    integers (TICKS . FORM), where TICKS is the number of clock ticks and FORM
    is the clock frequency in ticks per second.  (Currently the positive
    integer should be at least 65536 if the returned value is expected to
    be given to standard functions expecting Lisp timestamps.)  If FORM is
    t, the time is returned as (TICKS . PHZ), where PHZ is a platform dependent
    clock frequency in ticks per second.  If FORM is ‘integer’, the time is


-- Stefan