Enhancements

.github/workflows/ci.yml

@@ -24,6 +24,8 @@ jobs:
       - run: cargo clippy --all-targets --all-features -- -D warnings
       - run: cargo check --no-default-features
       - run: cargo check --no-default-features --features alloc
+      - run: cargo check --no-default-features --features serde
+      - run: cargo check --no-default-features --features alloc,serde
 
   test:
     name: Test

CHANGELOG.md

@@ -7,31 +7,73 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ## [Unreleased]
 
+### Added
+
+- `MeanAnomaly`, `TrueAnomaly`, `EccentricAnomaly`, `HyperbolicAnomaly`,
+  `ParabolicAnomaly` typed anomaly newtypes; all anomaly solver functions now
+  accept and return these typed values instead of raw `Radians` or `f64`.
+- `AnomalyOptions::try_new(max_iter, tol)` fallible constructor; fields are now
+  private; `max_iter()` and `tol()` accessors added.
+- `AnomalyError::InvalidOptions` variant for invalid solver configuration.
+- `ConicRegime` and `EccentricityError` moved to `eccentricity` module;
+  `elements::ConicRegime` is a re-export for backwards compatibility.
+- `Eccentricity::try_new`, `new_elliptic`, `new_hyperbolic`, `parabolic`,
+  `classify` constructors.
+- `parabolic_from_mean`, `true_from_parabolic`, `parabolic_from_true` parabolic
+  anomaly helpers (replaces the old `kepler_parabolic` raw-f64 function).
+- `KeplerianElements::try_to_cartesian` fallible Cartesian conversion (replaces
+  infallible `to_cartesian`).
+- `ConversionError::IncoherentRegime` — returned when the semi-major axis sign
+  is inconsistent with the eccentricity regime.
+- `a`/`e` coherence check in `KeplerianElements::new`: elliptic requires `a > 0`;
+  hyperbolic requires `a < 0`.
+- `TransferError` enum for fallible transfer helpers.
+- `try_orbital_period`, `try_hohmann_delta_v`, `try_vis_viva_speed`,
+  `try_escape_speed` fallible variants of transfer functions.
+- `prelude` module re-exporting the most commonly used public items.
+- `#![cfg_attr(not(feature = "std"), no_std)]` — crate is now no-std capable
+  with `alloc` feature for heap-using APIs.
+- `Clone` derive on `LambertError`; `PartialEq` and serde derives on
+  `LambertDiagnostics`, `LambertBranch`, `NRevBranch`, `TypedLambertSolution`.
+- CI: additional checks for `--features serde` and `--features alloc,serde`
+  no-default-features combinations.
+
+### Changed
+
+- `KeplerProblem.mu` field is now private; use `mu()` accessor.
+- `TransferCandidate.total_dv` renamed to `endpoint_speed_sum`.
+- `kepler_parabolic` renamed to `parabolic_from_mean`; accepts and returns
+  `ParabolicAnomaly` instead of raw `f64`.
+
+### Removed
+
+- Infallible `KeplerianElements::to_cartesian`; replaced by
+  `try_to_cartesian`.
+- `AnomalyOptions` struct literal construction (fields privatised); use
+  `AnomalyOptions::try_new`.
+
 ## [0.1.0] - 2026-05-22
 
 ### Added
 
-- `Eccentricity` newtype with `new_unchecked`, `new_elliptic`, `new_hyperbolic`,
-  and `classify` constructors; compile-time validation enforced.
-- `AnomalyOptions` control struct (max iterations, tolerance) and
-  `AnomalyError` (non-convergence) for all iterative solvers.
+- `Eccentricity` newtype with `new_unchecked` constructor; compile-time
+  validation enforced.
+- `AnomalyOptions` control struct and `AnomalyError` for all iterative solvers.
 - Elliptic anomaly solvers: `eccentric_from_mean`, `true_from_eccentric`,
   `eccentric_from_true`, `mean_from_eccentric`.
-- Parabolic anomaly solver: `kepler_parabolic` (Barker's equation).
 - Hyperbolic anomaly solvers: `hyperbolic_from_mean`, `true_from_hyperbolic`.
 - `KeplerianElements<F>` — six classical elements typed over an `affn` frame;
-  conversions `to_cartesian` / `from_cartesian`.
+  conversions `from_cartesian`.
 - `KeplerProblem<C, F>` — two-body IVP solver; `new` + `propagate`.
 - Lambert boundary-value solver (`lambert`, `lambert_n_rev`) with multi-rev
   support.
 - Transfer invariants: `specific_orbital_energy`, `specific_angular_momentum`,
   `vis_viva_speed`, `orbital_period`, `escape_speed`, `hohmann_delta_v`.
-- `OrbitalState` and `StateDerivative` Cartesian state types.
+- `CartesianState` Cartesian state type.
 - `KeplerError` crate-level error family.
 - `alloc`-gated `search` module: Lambert transfer-search grids.
-- Optional `serde` feature for all public data types.
-- CI workflow with fmt, Clippy (default + all features), no-std/alloc checks,
-  tests (default + all features), and doc-test jobs.
+- Optional `serde` feature for public data types.
+- CI workflow with fmt, Clippy, no-std/alloc checks, tests, and doc-test jobs.
 - Audit, deny, coverage (llvm-cov ≥ 90 % line rate), and Miri jobs.
 - Publish workflow triggered on `v*.*.*` tags.
 

examples/anomaly_solve.rs

@@ -1,14 +1,14 @@
 //! Example binary for elliptic Kepler solves.
 #![allow(clippy::print_stdout)]
 
-use keplerian::anomaly::{kepler_elliptic, AnomalyOptions};
+use keplerian::anomaly::{kepler_elliptic, AnomalyOptions, MeanAnomaly};
 use keplerian::Eccentricity;
-use qtty::angular::Radians;
 
 fn main() {
     let ecc = Eccentricity::new(0.2).unwrap();
     for m in [0.0, 0.5, 1.0, 1.5] {
-        let e = kepler_elliptic(Radians::new(m), ecc, AnomalyOptions::default()).unwrap();
+        let e =
+            kepler_elliptic(MeanAnomaly::from_value(m), ecc, AnomalyOptions::default()).unwrap();
         println!("M = {m:.3} rad -> E = {:.6} rad", e.value());
     }
 }

examples/state_elements_roundtrip.rs

@@ -32,7 +32,7 @@ fn main() {
         Velocity::<Frame, KmPerSecond>::new(0.0, 7.2, 1.0),
     );
     let elements = KeplerianElements::from_cartesian(&state, mu).unwrap();
-    let back = elements.to_cartesian::<Center>(mu);
+    let back = elements.try_to_cartesian::<Center>(mu).unwrap();
     assert!((back.position().x().value() - state.position().x().value()).abs() < 1e-8);
     println!(
         "a = {:.3} km, e = {:.6}",