YACLib / YACLib / 27293293670

99%

Build Type

push

github

Committed by web-flow

Commit Message

Trait-based error handling for all abstractions (#276)

Supersedes #258 (same idea, rebuilt on current main: SharedFuture,
UniqueCore/SharedCore split and the reworked combinators are covered).

### Purpose

Refactor yaclib's core primitives to support custom result types
natively. Instead of the hardcoded `std::variant`-based `Result<V, E>`,
every abstraction (`Future`, `Promise`, `Task`, `SharedFuture`,
combinators, coroutines) takes a **result trait** `T` (default
`DefaultTrait`) that defines the result container and error handling —
making yaclib interoperable with `std::expected`/`absl::StatusOr`-style
types with zero overhead and zero wrappers.

### Key changes

- `Future<V, E = StopError>` → `Future<V, T = DefaultTrait>` everywhere.
- New default `Result<V>`: `exception_ptr` + value union, single error
channel. `sizeof(Result<void>) == sizeof(std::exception_ptr)` (8 bytes,
was 16) where `no_unique_address` is supported.
- Cancellation is a cached `StopException` `exception_ptr`
(`StopPtr()`/`IsStop()`): no allocation per cancellation, no extra
atomics on the value path.
- `StopError`/`ResultError`/`ResultState` removed: the
Exception-vs-Error split unifies into one channel. **Behavior change**:
`[](std::exception_ptr)` recovery callbacks now also fire on
cancellation — use `yaclib::IsStop()` to distinguish.
- Trait interface (see `ResultTrait` docs in
`<yaclib/util/result.hpp>`): `Result<V>`/`Error` aliases, `MakeResult`,
`Ok`, `GetValue`/`GetError` (value-category-preserving accessors), `Get`
(value-or-throw, used by coroutine awaiters — containers need no
yaclib-specific members), `IsStop` (stop inspection in the trait's own
error vocabulary).

### yaclib_ext

New `include/yaclib_ext/` for integrations that require specific
libraries or standards, proving the flexibility claim with **raw**
vocabulary types:

- `yaclib_ext/std/expected.hpp` — `ExpectedTrait<E>`: `std::expected<V,
E>` as the container (C++23, including native `expected<void, E>... (continued)

Coverage Stats

296 of 296 new or added lines in 32 files covered. (100.0%)

6 existing lines in 3 files now uncovered.

2110 of 2122 relevant lines covered (99.43%)

1857961.08 hits per line