keyed_lens 0.1.0

Composable total and affine lenses for immutable aggregates, each carrying a stable, serializable FieldKey identity that addresses a field for reads, writes, diffs and patches.

0.1.0

Initial release.

• FieldKey + sealed Segment (NameSegment / IdSegment) — stable, serializable field identity with a frozen toPath() / parse() wire codec. hashCode is cached (a key is immutable and used as a Map / Set key on every validation, touch check and error lookup); == early-outs on a hash mismatch.
• Lens (total) / AffineLens (affine) with then / thenTotal composition; affine set / update no-op on a non-resolving path.
• ListItemLens + .at(id, matches) — by-id list-row access.
• Prism — minimal type-narrowing optic for sum types.
• whenPresent(), Opt (Some / None), KeyedRow.