named – keyword arguments for Haskell
named is a lightweight library for named function parameters (keyword
arguments) based on overloaded labels. Keyword arguments have several
advantages over positional arguments:
- they can be supplied in arbitrary order
- their names serve as documentation at call site
- it is impossible to accidentally mix them up
Unlike newtype wrappers, keyword arguments don't pollute the global namespace, don't require top-level definitions, and don't need to be exported.
This implementation of named parameters is typesafe, provides good type inference, descriptive type errors, and has no runtime overhead.
import Named createSymLink :: "from" :! FilePath -> "to" :! FilePath -> IO () createSymLink (Arg from) (Arg to) = ... main = createSymLink ! #from "/path/to/source" ! #to "/target/path"