Crate panproto_lens 

panproto-lens

Bidirectional lenses via protolens (schema-independent lens families).

Every schema migration is a lens with a get direction (= restrict, projecting data forward) and a put direction (= restore from complement, bringing modifications back). The lens laws (GetPut and PutGet) guarantee round-trip fidelity.

This crate provides:

• Lens: An asymmetric lens backed by a compiled migration.
• get / put: Forward and backward lens directions.
• Complement: Data discarded by get, needed by put.
• Protolens: A dependent function from schemas to lenses (Π(S : Schema | P(S)). Lens(F(S), G(S))).
• ProtolensChain: Composable sequence of protolenses.
• auto_generate: Automatic protolens generation from two schemas.
• compose(): Compose two lenses sequentially.
• check_laws: Verify GetPut and PutGet on a test instance.

The mathematical foundations are based on asymmetric lenses with complement (Diskin et al., 2011), GAT-based protolenses (natural transformations between theory endofunctors), and Cambria’s approach to schema evolution (Ink & Switch, 2020).

Re-exports

pub use asymmetric::Complement;

pub use asymmetric::get;

pub use asymmetric::put;

pub use auto_lens::AutoLensConfig;

pub use auto_lens::AutoLensResult;

pub use auto_lens::Stringency;

pub use auto_lens::auto_generate;

pub use auto_lens::auto_generate_candidates;

pub use auto_lens::auto_generate_candidates_with_hints;

pub use auto_lens::auto_generate_with_hints;

pub use candidate::CandidateStep;

pub use candidate::LensCandidate;

pub use complement_type::CapturedField;

pub use complement_type::ComplementKind;

pub use complement_type::ComplementSpec;

pub use complement_type::DefaultRequirement;

pub use complement_type::chain_complement_spec;

pub use complement_type::complement_spec_at;

pub use compose::compose;

pub use cost::chain_cost;

pub use cost::complement_cost;

pub use cost::verify_identity_cost;

pub use cost::verify_subadditivity;

pub use diff_to_protolens::DiffSpec;

pub use diff_to_protolens::KindChange;

pub use diff_to_protolens::diff_to_lens;

pub use diff_to_protolens::diff_to_protolens;

pub use edit_error::EditLensError;

pub use edit_lens::EditLens;

pub use edit_pipeline::EditPipeline;

pub use edit_provenance::EditProvenance;

pub use error::LawViolation;

pub use error::LensError;

pub use graph::LensGraph;

pub use laws::check_get_put;

pub use laws::check_laws;

pub use laws::check_put_get;

pub use optic::OpticKind;

pub use optic::classify_transform;

pub use optic::refine_scoped_optic;

pub use protolens::ComplementConstructor;

pub use protolens::FleetResult;

pub use protolens::Protolens;

pub use protolens::ProtolensChain;

pub use protolens::SchemaConstraint;

pub use protolens::apply_to_fleet;

pub use protolens::combinators;

pub use protolens::elementary;

pub use protolens::horizontal_compose as protolens_horizontal;

pub use protolens::lift_chain;

pub use protolens::lift_protolens;

pub use protolens::vertical_compose as protolens_vertical;

pub use symbolic::SymbolicStep;

pub use symbolic::simplify_steps;

pub use symmetric::CoherenceViolation;

pub use symmetric::SymmetricLens;

Modules

asymmetric

Asymmetric lens operations: get and put with complement tracking.

auto_lens

Automatic protolens generation pipeline.

candidate

Ranked candidate lenses with per-step explanations.

coercion_laws

Sample-based verification of declared coercion classes.

complement_type

Complement type system for protolenses.

compose

Lens composition.

cost

Complement cost computation forming a Lawvere metric on lens graphs.

diff_to_protolens

Convert schema diffs into protolens chains.

edit_error

Error types for edit lens operations.

edit_laws

Edit lens law verification.

edit_lens

Edit lens: translates individual edits between source and view schemas.

edit_pipeline

Per-pipeline-step edit translation for the edit lens.

edit_provenance

Provenance tracking for translated edits.

enrichment_registry

Cross-crate extension point for schema-enrichment synthesis.

error

Error types for lens operations.

fibration

Grothendieck fibration structure for the protolens framework.

graph

Weighted lens graph with Floyd-Warshall shortest paths.

hint

Forward-chaining hint propagation for auto-lens generation.

laws

Round-trip law verification for lenses.

layout_complement

The operational layout complement: the per-vertex fibres the emit review (put-direction) consumes.

optic

Optic classification for protolens chains.

protolens

Protolenses: schema-parameterized families of lenses.

symbolic

Symbolic simplification of protolens chains.

symmetric

Symmetric lenses via span composition.

Structs

Lens

An asymmetric lens with complement tracking.