Flix for Visual Studio Code

The official Visual Studio Code extension for the Flix Programming Language (flix.dev).

Flix is a next-generation reliable, safe, concise, and functional-first programming language.

Flix aims to have world-class Visual Studio Code support and our extension is based on the real Flix compiler infrastructure.

Features

• Semantic Syntax Highlighting

  • Code highlighting for *.flix files. This work best with the official vscode theme.

• Diagnostics

  • Compiler error messages.

• Auto-complete

  • Auto-complete as you type.
  • Auto-completion is context aware.
  • Type-directed completion of program holes.

• Snippets

  • Auto-complete common code constructs.

• Inlay Hints

  • Shows inline type information.

• Type and Effect Hovers

  • Hover over any expression to see its type and effect.
  • Hover over any local variable or formal parameter to see its type.
  • Hover over any function to see its type signature and documentation.

• Jump to Definition

  • Jump to the definition of any function.
  • Jump to the definition of any local variable or formal parameter.
  • Jump to the definition of any enum case.

• Find References

  • Find all references to a function.
  • Find all references to a local variable or formal parameter.
  • Find all references to an enum case.
  • Find all implementations of a trait.

• Symbols

  • List all document symbols.
  • List all workspace symbols.

• Rename

  • Rename local variables or formal parameters.
  • Rename functions.

• Code Lenses

  • Run main from within the editor.
  • Run tests from within the editor.

• Highlight

  • Highlights semantically related symbols.

• Semantic Tokens

  • Additional code highlighting hints provided by the compiler.

Installation

• Install the Flix Visual Studio Code extension.
  • The extension will automatically download the Flix compiler.

Alternative (for advanced users):

• Upon startup, the extension with look for a flix.jar compiler in the project root and use that if available.
  • This can be used to run a nightly (or custom-built) version of the compiler.

Requirements

• Requires Java 21 (or later).
  • Ensure that the java command is on your path.

For Developers

Information about running, debugging, and packaging the extension is available in DEV.md.