A tool for suggesting possible improvements to Haskell code, such as using alternative functions, simplifying code, and spotting redundancies.
HLint is a tool for suggesting possible improvements to Haskell code. It analyzes Haskell source files and provides hints about alternative functions, simplifications, and redundancies. The tool helps developers write more idiomatic and maintainable Haskell by highlighting areas where code can be cleaned up or optimized for readability.
Haskell developers of all levels, from beginners learning best practices to experienced programmers maintaining large codebases. It is particularly useful for teams enforcing consistent coding standards.
Developers choose HLint because it integrates seamlessly into their workflow, offers extensive customization, and focuses on teaching better Haskell style rather than just enforcing rules. Its ability to work with editors, CI systems, and refactoring tools makes it a versatile addition to any Haskell project.
Haskell source code suggestions
Open-Awesome is built by the community, for the community. Submit a project, suggest an awesome list, or help improve the catalog on GitHub.
Allows users to ignore, modify, or add project-specific hints via .hlint.yaml files, with examples like banning unsafePerformIO or enabling extra hint groups.
Works with editors, IDEs, CI systems, and refactoring tools, including Emacs plugins, GitHub actions, and automatic application of suggestions using --refactor.
Classifies hints as warnings (always desirable) or suggestions (require judgment), encouraging developers to think critically about code style rather than blindly following rules.
Supports fast analysis on multi-core systems with flags like -j4, and can fetch pre-compiled binaries for CI to avoid compilation overhead.
Analyzes each module in isolation without type information or knowledge of imports, leading to potential issues with fixity declarations or scoped names, as admitted in the bugs section.
Fails to parse code using custom preprocessors or certain GHC extensions like Strict or RebindableSyntax, requiring manual disabling and causing parse errors.
Some hints, such as eta reduction, can change program semantics in the presence of seq or type defaults, and the tool warns about increased laziness or removed errors.