Crux is a work in progress. Roughly, its current state is as follows. You can also look at the GitHub issues.

Working

  • Type inference
  • Sum types
  • Tuples
  • Flow control (if, while, match, for)
  • Row-polymorphic records
  • Type aliases
  • Mutable locals and record fields
  • Generics, including weak polymorphism under mutability
  • Traits
  • Modules
  • Exceptions
  • JS FFI
  • Build system

Not Done

  • Standard library
  • DOM APIs
  • JSX / React integration
  • async/await
  • Associated types
  • Package manager
  • Optimizing compiler
  • Amazing error messages
  • npm package output