Open Source Haskell Code Formatters

nixfmt is a code formatter for the Nix expression language, aiming to provide consistent and idiomatic formatting for Nix files. It is written in Haskell and designed to be fast, predictable, and fully automatic with zero configuration. nixfmt helps Nix developers maintain readability and code consistency across large codebases, facilitating collaboration and version control workflows.

elm-format formats Elm source code according to a standard set of rules based on the official Elm Style Guide. It makes code easier to write, because you never have to worry about minor formatting concerns while powering out new code. It makes code easier to read, because there are no longer distracting minor stylistic differences between different code bases. As such, your brain can map more efficiently from source to mental model. It makes code easier to maintain because you can no longer have diffs related only to formatting; every diff necessarily involves a material change. It saves your team time debating how to format things because there is a standard tool that formats everything the same way. It saves you time because you don't have to nitpick over formatting details of your code.