Sobakasu Language

Visual Studio Code language support for Sobakasu and Udon Assembly (UASM).

Sobakasu is a Udon-first programming language and compiler designed for developing VRChat worlds without depending on C# or UdonSharp.

Features

Sobakasu

Language support for .sobakasu files:

• Syntax highlighting
• // line comments
• /* ... */ block comments
• Bracket matching
• Automatic closing of brackets and quotes
• Automatic indentation

state {
  count: i32 = 0;
}

behavior {
  on interact(state) {
    state.count += 1;
  }
}

Udon Assembly

Syntax highlighting for .uasm files is also included.

.data_start

.data_end

.code_start

    PUSH, 0x00000000
    EXTERN, "UnityEngineDebug.__Log__SystemObject__SystemVoid"

.code_end

About Sobakasu

Sobakasu is a programming language and toolchain designed specifically for the VRChat Udon VM.

Its main goals are:

• Udon-first — designed around Udon rather than adapting an existing general-purpose language
• C#-independent — not constrained by C# syntax or language semantics
• Unity integration — intended to integrate directly with the VRChat world development workflow
• Higher-level language features — providing a more expressive language while compiling to Udon Assembly

Sobakasu is currently under active development and is not yet recommended for production use.

Installation

Install Sobakasu Language from the Visual Studio Code Marketplace.

For local development, the extension can also be installed from a .vsix package:

code --install-extension sobakasu-<version>.vsix

Supported File Types

Compiler and Unity Package

This extension provides Visual Studio Code language support.

The Sobakasu compiler and Unity integration are distributed as part of the main Sobakasu project.

See the main repository for installation instructions and documentation:

github.com/skytomo221/Sobakasu

Documentation

• Sobakasu website
• GitHub repository
• Issue tracker

Development Status

Run the TextMate tokenization regression tests with Node.js and npm from this directory:

npm ci
npm test
npm run package:check

npm run package creates a local VSIX. Test and packaging tools are development dependencies only.

The tests use vscode-textmate and vscode-oniguruma, check the compiler's hard keyword vocabulary, and verify identifier coverage against its Unicode 16.0 XID tables. Identifier patterns use Oniguruma's XID_Start / XID_Continue properties with _ and an unassigned-character (Cn) fallback: older engine Unicode tables can then keep newer Sobakasu identifiers intact. Four newer XID continuation characters (U+200C, U+200D, U+30FB, U+FF65) are also included explicitly. This intentionally permits some names that the compiler rejects; highlighting does not validate source code.

maybe is highlighted inside function extern bindings, including maybe out ABI parameters. Ordinary identifiers named maybe keep their identifier scope. Synchronization modes are highlighted only inside sync(...).

Sobakasu and this extension are still under development.

Language syntax and editor support may change as the language evolves.

License

MIT License