Editor Setup (VS Code)

FScript has an official VS Code extension with Language Server support.

Install

Choose your marketplace:

• VS Code Marketplace: https://marketplace.visualstudio.com/items?itemName=MagnusOpera.fscript
• Open VSX: https://open-vsx.org/extension/MagnusOpera/fscript

What you get

The extension provides:

• syntax highlighting,
• diagnostics,
• completion,
• hover,
• document symbols,
• go-to-definition and references,
• rename,
• semantic tokens,
• inlay hints.

Runtime requirement

The extension uses .NET runtime acquisition via .NET Install Tool when needed and can also use dotnet from your PATH.

Recommended first workflow

1. Install the extension.
2. Open a folder containing .fss files.
3. Create hello.fss and type a small function.
4. Confirm diagnostics/completion are active.
5. Run the script from terminal with fscript hello.fss.

Related docs

• Continue with Language Tour.
• Go deeper in Language chapters.

Numeric signatures

The extension highlights numeric annotations and shows inferred arithmetic signatures such as (x: numeric) -> (y: numeric) -> numeric. An int or float annotation specializes a shared arithmetic type. Mixed numeric types and nonnumeric calls are reported as errors.

See Type System for examples and the type hierarchy.