BR Language Server

VS Code extension providing language intelligence, compile/run, and decompile support for the Business Rules (BR) programming language.

Features

Language Intelligence

Diagnostics — syntax errors, function issues, undefined functions, unused variables
Completions with resolve support
Hover — builtin and user-defined function signatures
Signature help — parameter hints for builtin and user-defined functions as you type
Go to definition
Find references — scope-aware variable resolution
Rename — workspace-wide, scope-aware
Document & workspace symbols
Code actions — quick fixes
Semantic token highlighting

Compile & Run

Compile .brs/.wbs to .br/.wb via the Lexi preprocessor (Ctrl+Shift+B)
Auto-compile on save with status bar toggle
Run with integrated terminal (Ctrl+Shift+R)
Launch configurations via .vscode/launch.json
Selectable bundled runtime: BR 4.3 or BR 4.2, from the status bar
Cross-platform: Windows (brnative.exe, brnative.42.exe) and Linux (brlinux)

Decompile

Decompile .br/.bro/.wb/.wbo back to source
Batch decompile entire folders
Auto-decompile when opening compiled files
Configurable style formatting
Explorer context menu integration

Editor Enhancements

Auto line numbering on Enter (configurable increment and padding)
Next/previous occurrence navigation (Ctrl+Shift+Down/Up)
Tree-sitter node inspector for debugging language parsing (Ctrl+Shift+Alt+I)
Workspace-wide diagnostic scan with CSV export (Ctrl+Alt+7)
Code snippets for file I/O, Lexi, loops, and statements

Getting Started

Requirements

VS Code 1.66+

Windows is fully supported. Remote SSH to Linux is experimental.

Development

pnpm i && cargo build
Press F5 in VS Code to launch the Extension Development Host
Open a .brs or .wbs file

Settings

Setting	Type	Default	Description
`br.autoLineNumbers.enabled`	`boolean`	`true`	Auto-add line numbers on Enter
`br.autoLineNumbers.increment`	`number`	`10`	Default line number increment
`br.autoLineNumbers.zeroPadding`	`number`	`5`	Digits for line numbers (e.g. 5 → `00100`)
`br.diagnostics.syntax`	`boolean`	`true`	Report syntax errors
`br.diagnostics.functions`	`boolean`	`true`	Report function diagnostics
`br.diagnostics.undefinedFunctions`	`boolean`	`true`	Report undefined function calls
`br.diagnostics.unusedVariables`	`boolean`	`true`	Report unused DIM variables and LIBRARY imports
`br.runtimeVersion`	`string`	`"4.3"`	Bundled BR runtime used to compile and run (`"4.3"` or `"4.2"`)
`br.executable`	`string`	`""`	Path to a BR executable. Overrides `br.runtimeVersion`
`br.wbconfig`	`string`	`""`	Wbconfig passed to compile/decompile operations
`br.decompile.sourceExtensions`	`object`	`{".br":".brs", ...}`	Compiled → source extension mapping
`br.decompile.styleCommand`	`string`	`"indent 2 45 keywords lower..."`	Style command applied after decompiling
`br.trace.server`	`string`	`"off"`	Trace communication with the language server

Runtime Version

The extension bundles two BR runtimes. The status bar shows which one is active — click it (or run BR: Select Runtime Version) to switch between BR 4.3 and BR 4.2. The choice is stored in br.runtimeVersion and applies to everything that spawns BR: compile, run, decompile, line numbering, proc search, and BR: Show Runtime Info.

BR 4.2 is bundled for Windows only; the bundled Linux runtime is 4.3.
Setting br.executable overrides the selection entirely — the status bar then reads BR (custom).
An explicit executable in a br launch configuration overrides it for BR: Run only, so a launch config that pins a runtime can compile with one version and run with another. Omit executable to follow the setting.
Compiled .br/.wb objects are version-specific; recompile after switching.

Launch Configuration

Add a br configuration to .vscode/launch.json:

{
  "version": "0.2.0",
  "configurations": [
    {
      "type": "br",
      "request": "launch",
      "name": "Run BR",
      "executable": "",
      "wbconfig": "",
      "wsid": "",
      "cwd": "${fileDirname}"
    }
  ]
}

Property	Description
`name`	Label shown when choosing between configurations.
`executable`	Path to BR executable. Omit to use the bundled runtime selected by `br.runtimeVersion`.
`wbconfig`	Path to wbconfig file (passed as `-[filename]`).
`wsid`	Workstation ID (e.g. `42`, `42+`, `21+5`, `WSIDCLEAR`).
`cwd`	Working directory. Defaults to `${fileDirname}`.

executable, wbconfig, and cwd support VS Code variables: ${workspaceFolder}, ${extensionPath}, ${file}, ${fileDirname}, ${fileBasename}, ${fileBasenameNoExtension}. A path that is still relative after substitution is resolved against the workspace root. wsid is passed to BR verbatim — variables are not expanded there.

With more than one br configuration, BR: Select Launch Configuration picks the active one, and the choice is remembered per workspace. BR: Run Program prompts on first use if nothing has been picked yet.

Keybindings

Keybinding	Command	Context
`Ctrl+Alt+7`	Scan All Project Source	Global
`Ctrl+Shift+Down`	Next Occurrence	BR editor
`Ctrl+Shift+Up`	Previous Occurrence	BR editor
`Ctrl+Shift+B`	Compile Program	BR editor
`Ctrl+Shift+R`	Run Program	BR editor
`Enter`	Auto Insert Line Number	BR editor (no widget open)
`Ctrl+Shift+Alt+I`	Toggle Tree-Sitter Inspector	BR editor

License

MIT

BR Language Extension

Christopher Shields