Ptime.Span
POSIX time spans.
WARNING. A POSIX time span is not equal to an SI second based time span see the basics.
type t = span
The type for signed, picosecond precision, POSIX time spans.
val v : (int * int64) -> span
val of_d_ps : (int * int64) -> span option
of_d_ps (d, ps)
is a span for the signed POSIX picosecond span d
* 86_400e12 + ps
. d
is a signed number of POSIX days and ps
a number of picoseconds in the range [0
;86_399_999_999_999_999L
]. None
is returned if ps
is not in the right range.
val to_d_ps : span -> int * int64
to_d_ps d
is the span d
as a pair (d, ps)
expressing the POSIX picosecond span d
* 86_400e12 + ps
with ps
in the range [0
;86_399_999_999_999_999L
]
val of_int_s : int -> span
of_int_s secs
is a span from the signed integer POSIX second span secs
.
val to_int_s : span -> int option
to_int_s d
is the span d
as a signed integer POSIX second span, if int
's range can represent it (note that this depends on Sys.word_size
). Subsecond precision numbers are truncated.
val of_float_s : float -> span option
of_float_s secs
is a span from the signed floating point POSIX second span d
. Subpicosecond precision numbers are truncated.
None
is returned if secs
cannot be represented as a span. This occurs on Stdlib.nan
or if the duration in POSIX days cannot fit on an int
(on 32-bit platforms this means the absolute magnitude of the duration is greater than ~2'941'758 years).
val to_float_s : span -> float
to_float_s s
is the span d
as floating point POSIX seconds.
Warning. The magnitude of s
may not be represented exactly by the floating point value.
compare d d'
is a total order on durations that is compatible with signed time span order.
Note. The following functions rollover on overflows.
round ~frac_s t
is t
rounded to the frac_s
decimal fractional second. Ties are rounded away from zero. frac_s
is clipped to the range [0
;12
].
truncate ~frac_s t
is t
truncated to the frac_s
decimal fractional second. frac_s
is clipped to the range [0
;12
].
val pp : Stdlib.Format.formatter -> span -> unit
pp ppf d
prints an unspecified, approximative, representation of d
on ppf
.
The representation is not fixed-width, depends on the magnitude of d
and uses locale independent SI prefixes on seconds and accepted non-SI units. Years are counted in Julian years (365.25 SI-accepted days) as defined by the International Astronomical Union (IUA).
The representation is approximative. In particular beyond 60 seconds it only keeps the two most significant time units and rounds towards the infinity. The latter means that case arising, it always over approximates durations.
Warning Becomes unprecise (but does not overflow) if the absolute number of POSIX days in the time span is greater than max_int /
4
(on 32-bit platforms this is ~735'439 years)
val dump : Stdlib.Format.formatter -> span -> unit
dump ppf s
prints an unspecified raw representation of d
on ppf
.