ucal-core

Ticks, tiers, text and binary forms, UCIDs, exact rationals and certified intervals.

Part of ucal, an implementation of RFC UCAL-1: absolute time as an unsigned integer count of Planck-time units since a stipulated datum, with a positional base-5 calendar over it.

The foundation crate: the tick type, the base-5 tier grid, the two text forms and the fixed 64-byte binary form, UCIDs, exact rational and interval arithmetic, and profile UC-1.

Two interchangeable integer backends sit behind one trait — bnum::U512 by default (stack-allocated, Copy, const-constructible) and num_bigint::BigUint under --features bigint. Both accept and reject exactly the same values.

Builds no_std with no allocator at all; what goes with the allocator is radix formatting — the text codecs and the continued-fraction expansions. The tick type, all of the checked arithmetic, Ratio, RatInterval, the tier grid and the binary codec remain.

use ucal_core::{Instant, UC1, Profile};

let t = UC1::bridge_epoch()?;
println!("{}", t.ticks());

Properties

• Unsigned. Tick 0 is the datum; nothing precedes it. Subtraction that would go negative is an error, not a wrap.
• No floats. Anywhere. Enforced by a workspace lint that also reports every exemption it honours.
• Uncertainty kept. A value stated to a coarser tier is an interval, and the type carries it.

Status

Early — the API is not yet stable.

Licence

Mozilla Public License 2.0 — see LICENSE.