`History` takes its observer by value and never hands it back, so a
caller who wanted to read what an observer recorded had no way to keep a
handle to it. The natural spelling did not compile:
let recorder = Arc::new(Recorder::default());
History::builder().observer(Arc::clone(&recorder))
// error[E0277]: `Arc<Recorder>: Observer<i64>` is not satisfied
The workaround was for every observer to wrap each of its own fields in
an `Arc` and derive `Clone` — one allocation and one lock per field, a
pattern each implementor had to rediscover, and nothing documenting it.
Adds blanket `Observer` impls for `Arc<O>`, `Box<O>` and `&O`. All are
`?Sized`, so `Arc<dyn Observer<T>>` and `Box<dyn Observer<T>>` work too
and an observer can be chosen at runtime. Also adds
`History::observer()` and `into_observer()`, so a non-shared observer's
state can be inspected in place or reclaimed after `converge` without
needing interior mutability at all.
`tests/observer.rs` is simplified to the shared spelling, so the
recommended pattern is the one demonstrated rather than the workaround.
Closes#40
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011hcFjNDmHXZF8URGLku5zZ
Three unrelated small defects, all requiring signature changes:
- `Game::one_v_one` hardcoded `GameOptions::default()`, so a 1v1 could
never set `p_draw` or convergence options — and a drawn 1v1 was
therefore unreachable through it, since the default `p_draw` is zero.
It now takes `&GameOptions` like every other constructor.
- `Observer::on_batch_processed` was declared on the trait and never
called from anywhere: implementors wired up a callback that could not
fire. It is now called after each slice sweep, and renamed
`on_slice_processed` to match the vocabulary the codebase adopted in
T2 — the unit of work is a `TimeSlice`, not a batch. A slice is swept
once travelling backward and once forward, so a multi-slice history
fires it twice per slice per iteration; the doc comment says so.
- `pub mod factors` sat beside `pub(crate) mod factor`, two module paths
differing by one character with only one of them importable. The
public facade is now `graph`.
Tests cover each as a behaviour rather than a compile check: a drawn 1v1
succeeds only when p_draw is supplied, and the observer tests fail if
any callback stops firing.
BREAKING CHANGE: `Game::one_v_one` takes a fourth `&GameOptions`
argument; `Observer::on_batch_processed` is renamed
`on_slice_processed`; the `factors` module is renamed `graph`.
Closes#21
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011hcFjNDmHXZF8URGLku5zZ
logaritmiskandClaude Opus 5