v0.2.0 - Separating Architecture and Implementation

Release Notes — v0.2.0 (2026-05-27)

This release is a major restructuring of the project since v0.1.0: the repository has been split into a Cargo workspace. dataset-core now contains only the architecture layer, while a new companion crate dataset-ml houses all built-in dataset loaders. The two crates are published to crates.io independently.

Crate	Version
dataset-core	0.1.0 → 0.2.0
dataset-ml	0.1.0 (initial release)

⚠️ Breaking Changes

• Workspace split: dataset-core now only ships Dataset<T>, the utils module, and the error module. All built-in dataset loaders have moved to the new dataset-ml crate.

• datasets feature removed: the former datasets feature on dataset-core is gone. Use dataset-ml instead.

• Import path changes (loaders moved to dataset-ml):

  Old path (dataset-core 0.1.x)	New path (dataset-ml 0.1.0)
  dataset_core::datasets::iris::Iris	dataset_ml::iris::Iris
  dataset_core::datasets::boston_housing::BostonHousing	dataset_ml::boston_housing::BostonHousing
  dataset_core::datasets::diabetes::Diabetes	dataset_ml::diabetes::Diabetes
  dataset_core::datasets::titanic::Titanic	dataset_ml::titanic::Titanic
  dataset_core::datasets::wine_quality::red_wine_quality::RedWineQuality	dataset_ml::wine_quality::red_wine_quality::RedWineQuality
  dataset_core::datasets::wine_quality::white_wine_quality::WhiteWineQuality	dataset_ml::wine_quality::white_wine_quality::WhiteWineQuality

  There is no longer a datasets:: namespace — modules sit directly at the dataset_ml crate root, and every dataset struct is also re-exported at the crate root for convenience.

• utils function renames:

  • prepare_download_dir → evaluate_storage
  • download_dataset_with → acquire_dataset

• Download backend swap: replaced downloader with ureq. The download_to API was refactored and now supports an optional custom filename.

• Slimmer error payloads: DataFormatError no longer formats the offending record into the error message. Error output is more compact and avoids echoing raw data.

✨ Added

• Structured error handling: thiserror is now used to derive DatasetError / DataFormatErrorKind. Detailed variants, a consistent [dataset_name] ... prefix, and From impls for UreqError, ZipError, and std::io::Error mean ? just works inside loader closures.
• dataset-ml initial release: ships loaders for Iris, Boston Housing, Diabetes, Titanic, and Red / White Wine Quality. Wine Quality is split into red and white submodules that share parse_wine_data_to_array.
• Semantic tests across the board: dataset integration tests now assert value constraints, consistency checks, and finiteness — not just shapes.
• Documentation upgrades: each dataset module gained detailed module-level docs covering features, target variable, sample count, applications, and source.
• Chinese localization: README.zh-CN.md added for dataset-core, dataset-ml, and the workspace root.

🔧 Changed

• Dependency bumps: ureq → 3.3.0, thiserror → 2.0.18, zip → 8.5.1.
• Shared metadata (edition, rust-version, authors, license, repository) lifted into [workspace.package]; shared dependency versions live in [workspace.dependencies].
• Doctests that create files on disk are now marked no_run, so cargo test --doc no longer leaves stray artifacts behind.
• Removed redundant module-level docs from error.rs and stale markdown links in utils docs.

📦 Installation

[dependencies]
dataset-core = "0.2.0"           # architecture layer: Dataset<T> + utils + error
dataset-ml   = "0.1.0"           # add this only if you want the built-in loaders

If you only need the Dataset<T> container (zero external dependencies), no features are required. Enable features = ["utils"] to pull in acquire_dataset / download_to / unzip / SHA-256 helpers. dataset-ml transitively enables dataset-core/utils, so you don't need to configure it manually.