Guile Formatter

Purpose-built tool for Guile/Lisp code that enforces a deterministic formatting style. It parses code into an abstract syntax tree and outputs a consistently indented, line-broken source while preserving comments. This reduces cognitive load during reviews and simplifies large-scale refactors. The formatter integrates with local workflows and CI pipelines, enabling pre-commit or pre-merge checks to enforce style standards without manual intervention.
Core behavior focuses on readability and maintainability: indent all nested forms by a configurable amount, align closing parens with their opening, and respect existing comments. It handles common Guile and Lisp constructs like let, define, if, cond, and lambda forms with language-aware rules. When a form spans multiple lines, each argument can be placed on its own line or grouped under the opening brace, depending on settings.
It differentiates itself by offering precise control over continuation lines, max line length, and trailing whitespace handling, while preserving semantics and avoiding macro or macro-expander changes. The results are reproducible across environments given the same inputs and settings, supporting reproducible code reviews and easier onboarding for new contributors.
Typical use cases include standardizing a legacy Guile codebase, preparing patches for review with a clean diff, or enforcing a project-wide style guide across multiple repositories; teams can adopt the tool as a local pre-commit hook or CI step, ensuring new changes comply with the chosen formatting policy.