Haskell Formatter

The tool formats Haskell source code to a consistent, readable style without altering program logic. It focuses on indentation, alignment, and line wrapping while preserving comments, pragmas, and module headers. The process is deterministic, producing the same output for identical input, which simplifies code reviews and diffs. It is designed to work with standard Haskell 98/2010 syntax and common extensions.
Conceptually, the formatter tokenizes the input, builds an internal representation of declarations and expressions, and applies layout rules. It can respect a user-specified line length, choose between profiles, and handle do-notation, case expressions, and where blocks. The aim is to produce clean, idiomatic code that remains faithful to the original semantics.
Who benefits: developers seeking consistent style, code reviewers who rely on stable diffs, educators preparing examples, and teams enforcing a shared formatting standard. Use cases include preparing commits, producing readable samples for documentation, and ensuring multi-developer repositories maintain uniform formatting across modules.
Unique value: fast, language-aware formatting with predictable outputs and safe handling of large files. It supports multiple profiles, partial formatting, and non-destructive edits. Output can be copied into editors, CI pipelines, or integrated into build steps, enabling reliable formatting without requiring a local formatter installation.