Re: [RFC] Duration class

On 2026-07-02 05:22, Tim Düsterhus wrote:

To close this out ourselves: While having a static sum() method works for Durations, since the Duration with addition forms an abelian group, this doesn't work for the other future-scope classes where addition doesn't form an (abelian) group. More specifically: Adding two Instants together is not a meaningful operation. Adding a Duration to an Instant however is. If you want the appropriate mathematical structure, the timeline models a one-dimensional real affine space, in which Durations are vectors and Instants are points; it's a vector space that has forgotten its origin (the choice of epoch is arbitrary and not a distinguished point of the space - as evidenced by how many of them there are).