[QDP] Rust code quality and website improvements for Apache Mahout (QDP & site)

[rich7420]

Background

• QDP: GPU-accelerated quantum state encoding with a Rust core (qdp-core), CUDA kernels (qdp-kernels), and PyO3 bindings (qumat.qdp / _qdp). Keeping the Rust stack in good shape and visible (e.g. via rustdoc) is part of project health.
• Website: Built with Docusaurus; docs/ is the source of truth. Work here includes site code (config, scripts, components), fixing link and nav issues, integrating API docs, and CI.

Project context

• QDP encodings: qdp/qdp-core/src/gpu/encodings/ — QuantumEncoder trait, get_encoder, encodings: amplitude, angle, basis, iqp.
• Website: Docusaurus 3.x; source of truth docs/ (sync script copies into website/ before build).
• QDP API: Encoding methods "amplitude" | "angle" | "basis" | "iqp" | "iqp-z"; see docs/qdp/api.md.

Concrete improvements

Rust (QDP)

• Unsafe scope refactor: Narrow unsafe blocks; keep setup/teardown outside; add // SAFETY: where needed; avoid new broad unsafe regions.
• Doc coverage: Add or fix /// / //! for public items (first-line summary; optional # Examples / # Panics). Use cargo doc --no-deps → target/doc/.
• Lints and style: Fix cargo clippy warnings; remove dead code and unused imports; rustfmt.
• Small refactors: Extract helpers, clarify names, shorten long functions; no behavior change.
• Tests: Add or tighten unit tests where coverage is low; keep tests fast and deterministic.

Website

• Link errors: Fix broken links, wrong URLs, and redirect issues in docs/ and the built site.
• Site programming: Fix or improve Docusaurus config, sync scripts, or components.
• Nav and sidebar: Align labels and order with content; fix inconsistencies.
• Doc build in CI: Run cargo doc --no-deps (and optionally Python doc generation); fail on errors.
• Placeholders: Replace "TODO: Add API reference" with a link or short summary.

Deliverables (suggested)

• Rust: At least one concrete improvement (e.g. unsafe refactor, doc coverage, or small refactor) with tests; notes in PR where useful.
• Rust docs: Public API in qdp-core documented for cargo doc --no-deps; optionally wired into the doc pipeline.
• Website: At least one of: site programming, link fixes, API doc integration, or CI doc builds.
• Docs: Short note in docs/ or CONTRIBUTING on Rust doc conventions and where to find rustdoc.

References (official dev docs)

Resource	URL
Rust	doc.rust-lang.org
rustdoc	doc.rust-lang.org/rustdoc/
How to write documentation	doc.rust-lang.org/rustdoc/how-to-write-documentation.html
cargo doc	doc.rust-lang.org/cargo/commands/cargo-rustdoc.html
RFC 505 (API comments)	rust-lang.github.io/rfcs/0505-api-comment-conventions.html
Rust CUDA (guide)	rust-gpu.github.io/rust-cuda
NVIDIA CUDA best practices	docs.nvidia.com/cuda/cuda-c-best-practices-guide
Docusaurus	docusaurus.io

[0lai0]

Hi @rich7420 ,

I would love to take on this GSoC project and help drive these improvements.

I’ve already contributed a few PRs to Apache Mahout and have been deeply exploring the Rust codebase and website infrastructure. Because of this, I am fairly familiar with the current architecture, existing documentation gaps.

I’ve started thinking about possible approaches and drafted a preliminary plan:

• Rust Cleanup: Resolving lints, removing dead code, and boosting unit test coverage for stability.
• Safety & Docs: Scoping down unsafe blocks with strict annotations and enriching public API Rustdocs.
• Site Integration: Fixing broken links, resolving Docusaurus issues.

I am happy to discuss this further or start with a small PoC if that would be helpful.

Thanks :- )

[400Ping]

@rich7420 I think some of the scope are the same with the API documentation issue, may discuss in community sync.