Public API gains:
History::add_events<I: IntoIterator<Item = Event<T, K>>>(events)
-> Result<(), InferenceError>
which accepts the typed Event<T, K> shape added in Task 10. Ranks
from Outcome::Ranked are mapped to the legacy "higher f64 = better"
results internally.
add_events_with_prior now takes Vec<T> for times (was Vec<i64>),
generifying the whole internal path over T in a single fully-generic
impl<T: Time, D: Drift<T>, O: Observer<T>, K> block. The i64-specific
block is gone; record_winner/record_draw are now generic over T.
add_events_with_prior stays pub (not pub(crate)) because the ATP
example calls it directly with pre-built Index-based composition;
the new typed add_events is the primary public API going forward.
In-crate tests updated to call add_events_with_prior with an empty
HashMap. tests/api_shape.rs added with 3 integration tests covering
bulk ingest, draw, and mismatched-outcome error.
Part of T2 of docs/superpowers/specs/2026-04-23-trueskill-engine-redesign-design.md.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
InferenceError gains MismatchedShape (user-input length mismatches),
InvalidProbability (p_draw out of [0, 1]), and ConvergenceFailed
(exceeded max_iter without hitting epsilon). NegativePrecision stays.
History::add_events_with_prior and History::add_events now return
Result<(), InferenceError>. The previous assert! macros checking
composition/results/times/weights shape are replaced by matched
error returns.
Internal debug_assert! macros for arithmetic invariants stay; this
change only affects boundary validation of user input.
Tests updated to call .unwrap() on the Result. The old signatures
will be fully replaced in Task 15 (typed add_events(iter)) and the
nested-Vec wrapper removed in Task 20.
Part of T2 of docs/superpowers/specs/2026-04-23-trueskill-engine-redesign-design.md.
The former name collided with the popular indexmap crate. KeyTable
lives in its own module. Public API unchanged beyond the rename.
Part of T2 of docs/superpowers/specs/2026-04-23-trueskill-engine-redesign-design.md.
Mul and Div become two f64 adds/subs with no sqrt in the hot path.
mu() and sigma() are computed on demand from stored pi/tau.
Key implementation notes:
- exclude() returns N00 when var <= 0 to avoid inf/inf = NaN when
two Gaussians have the same precision (ULP-level round-trip error
from the pi→sigma accessor).
- Mul<f64> by 0.0 returns N00 (point mass at 0), matching old behavior.
- from_ms(0, 0) == N00 {pi:inf, tau:0}; from_ms(0, inf) == N_INF {pi:0, tau:0}.
Golden values in test_1vs1vs1_draw updated: nat-param arithmetic
rounds mu to 25.0 (was 24.999999) and shifts sigma by ~3e-7.
Both differences are bounded and validated against the original Python
reference values.
Part of T0 engine redesign.
