Re: [PHP-DEV] [RFC] Duration class

Hi

On 2026-07-14 10:45, Pierre Joye wrote:
>> > - it is awkward to have nanoseconds in setSeconds out of nowhere. I
>> > understand some external factor (other entities) leading to that
>> > decision but that creates illogical, inconsistent and confusing
>> > semantic boundaries. A box can contain apples does not mean
>> > setDimension should use apples with a limit on top. Or an apple can be
>> > used with a box that does not make an apple's unit in square feet.
>> 
>> As outlined above, I believe this special casing of the “subsecond
>> boundary” is common in the real world and human communication.
> 
> The human communication part is how the Duration provides its
> information. That's not correlated to how they are or can be provided.
> It is just as common in the real world to have duration information in
> one unit only and decimal. F.e. 234.54ms. or 3.4 hours, etc. the

I'm not typically seeing decimals being used for units smaller than 
seconds. 234.54ms would typically be communicated as either 234_540 
microseconds with an explicit ±10 microseconds to indicate the number of 
significant figures, or as 0.23454s. But this might be another case of 
“we made different experiences and thus feel the design should be 
different”.

Allowing the latter would effectively be a floating point 
representation, which is planned to be supported as an input for future 
scope. It needs some more thought than the fixed-point (seconds + nanos) 
decimal, because of the finite precision of IEEE-754 double precision 
representation.

> set<Unit> method can extremely easily handle this. And the

Small terminology note: There are no, and will be no setters. There's 
just the named constructors (`from<Unit>`).

> inconsistency of having nanoseconds, and only nanoseconds, on top of
> that makes it worse.

Best regards
Tim Düsterhus