Rust crate conventions

Coding conventions

• •Colocated tests: foo.rs has foo_test.rs in the same directory. Submodule tests use #[path = "foo_test.rs"].
• •A source file may have multiple test files (e.g. foo_math_test.rs, foo_test.rs)
• •Functional programming style
• •Types encode mathematical invariants, validated at construction
• •nalgebra for linear algebra, proptest for property-based testing

Mathematical documentation

• •Definitions, lemmas, and proofs live as doc comments on the corresponding types/functions
• •Long proofs are outsourced to colocated *_proof.md files
• •The Rust crates are self-contained mathematically — no dependency on thesis/. The thesis is downstream
• •Quality bar: specific, correct, detailed, clearly written enough that (1) Jörn can verify with low effort and (2) agents can rely on them when implementing

Testing philosophy

Two classes of tests, both applied excessively:

1. •Math proposition tests (due diligence falsification): proptest generators approximate mathematical quantifiers ("∀ polytopes K", "∀ A ∈ Sp(4)", etc.). Properties under test are mathematical propositions (e.g. J^2 = -I, symplectomorphisms preserve capacity).
2. •Standard correctness tests: Rust best practices for correctness-critical code — edge cases, invariant checking, regression tests.