Fjord

Fjord is a strict programming language that compiles to JavaScript.

Features

• JavaScript interop via .d.fj-definition files, a human-readable format that uses the same type notation as Fjord to describe the types of JavaScript dependencies.
• Enum types, also known as algebraic data types or (disjoint) union types. Like Scala 3 and Rust, Fjord uses the enum keyword to declare a type with multiple data constructors.
  • Pattern matching on enum types.
• Custom operators with precedence based on the first token, like Scala.
• Primitive value types
  • Integer type and integer literals
  • String type and string literals
  • Floating-point value literals.
  • Array type and array literals.
  • Escaped characters in string literals.
• Modules.
  • Importing all members of another module into the global scope.
  • Selectively importing functions, operators, and types from other modules.
  • Aliasing imported functions, operators, and types.
  • Aliasing imported modules.
• Tuples.
  • Type-system support.
  • Tuple value construction.
  • Destructuring in let bindings.
• Implicit values.
  • Resolution of concrete and polymorphic types.
  • Higher-order implicit value construction.
• Records, also known as structs, containing named data fields.
  • Shared record field access.
  • Record destructuring in let bindings.
  • Type and lifetime-safe record mutation.
• Typed holes, ?-prefixed identifiers where the compiler tells you what type of value it is missing for that identifier.
• Lifetime checking for sharing unique values safely, especially in partially applied or curried functions.
• Compiler optimizations for common patterns in functions and data structures.
  • Inline functions when deemed appropriate.