Canon

Language support for Canon — a programming language that compiles directly to WebAssembly components.

Features

• Syntax highlighting for .can files (TextMate grammar)
• Diagnostics as you type: lex errors, parse errors, sort-order violations, and type-check errors
• Hover documentation for built-in types and well-known constructors
• Go to definition
• Formatting via canon fmt (enable format-on-save for the canon language to get auto-sorted declarations)

All language features are powered by the compiler's built-in language server (canon lsp) — there is no separate LSP binary to install.

Getting the canon binary

The extension resolves the compiler in this order:

1. The canon.serverPath setting, if set
2. canon on your PATH
3. ~/.cargo/bin/canon
4. A previously downloaded binary

If none is found, the extension offers to download a prebuilt binary from GitHub releases automatically. You can also trigger this manually with the Canon: Download Language Server command, or install the compiler yourself:

curl -fsSL https://raw.githubusercontent.com/Almaju/canon/main/install.sh | sh

Settings

Commands

About Canon

Canon presents a small surface area — no let, no if/else, no comments, no local variables. Branching is dispatch on a union. Effects are passed as capabilities. Wherever ordering is discretionary, the compiler enforces alphabetical order.

Bool = False + True
User = Birthday * Username

main = () -> Unit {
    "hello".print()
}

See the language guide for more.