tree-sitter-bmb

Tree-sitter grammar for BMB (Bare-Metal-Banter) programming language.

Status

✅ v0.1.0 - Core grammar complete

Features

• Full BMB syntax support (functions, structs, enums, contracts)
• Syntax highlighting queries
• Code folding support
• Indentation queries
• Node.js and Rust bindings

Installation

Node.js

npm install tree-sitter-bmb

Rust

Add to your Cargo.toml:

[dependencies]
tree-sitter-bmb = "0.1"

Usage

Node.js

const Parser = require('tree-sitter');
const BMB = require('tree-sitter-bmb');

const parser = new Parser();
parser.setLanguage(BMB);

const sourceCode = `
fn add(a: i32, b: i32) -> i32
  pre a >= 0 and b >= 0
  post ret == a + b
= a + b;
`;

const tree = parser.parse(sourceCode);
console.log(tree.rootNode.toString());

Rust

use tree_sitter::Parser;
use tree_sitter_bmb::LANGUAGE;

fn main() {
    let mut parser = Parser::new();
    parser.set_language(&LANGUAGE.into()).unwrap();

    let source = r#"
        fn factorial(n: i64) -> i64
          pre n >= 0
          post ret >= 1
        = if n <= 1 then 1 else n * factorial(n - 1);
    "#;

    let tree = parser.parse(source, None).unwrap();
    println!("{}", tree.root_node().to_sexp());
}

Neovim

-- In your Neovim config
require('nvim-treesitter.configs').setup {
  ensure_installed = { 'bmb' },
  highlight = { enable = true },
}

Helix

Add to languages.toml:

[[language]]
name = "bmb"
scope = "source.bmb"
file-types = ["bmb"]
roots = []

Development

Prerequisites

• Node.js (v18+)
• tree-sitter CLI

Build

# Install dependencies
npm install

# Generate parser from grammar
npm run generate

# Build native module
npm run build

# Build WASM module
npm run build-wasm

Test

# Run tree-sitter tests
npm test

# Parse a file
tree-sitter parse example.bmb

Structure

tree-sitter-bmb/
├── grammar.js          # Grammar definition
├── package.json        # npm package
├── binding.gyp         # Node.js native binding
├── bindings/
│   ├── node/           # Node.js bindings
│   └── rust/           # Rust bindings
├── queries/
│   ├── highlights.scm  # Syntax highlighting
│   ├── folds.scm       # Code folding
│   └── indents.scm     # Auto-indentation
└── src/                # Generated parser (after build)
    └── parser.c

Query Files

File	Purpose
queries/highlights.scm	Syntax highlighting rules
queries/folds.scm	Code folding regions
queries/indents.scm	Automatic indentation

Supported Syntax

Definitions

• Functions (fn)
• Structs (struct)
• Enums (enum)
• Use statements (use)
• Attributes (@attr)

Types

• Primitives: i32, i64, f64, bool, String
• Unit: ()
• References: &T, &mut T
• Arrays: [T; N]
• Refinement types: i32{it > 0}

Expressions

• Control flow: if-then-else, match, while, for
• Binary operators: +, -, *, /, %, ==, !=, <, >, <=, >=, and, or
• Unary operators: -, not, &, &mut, *
• Ranges: ..<, ..=, ..
• Method calls: expr.method(args)
• Field access: expr.field
• Index access: expr[index]

Contracts

• Preconditions: pre <expr>
• Postconditions: post <expr>
• Where blocks: where { name: condition, ... }
• State references: x.pre, x.post

Special Keywords

• ret - Return value in postconditions
• it - Self-reference in refinement types
• new - Struct initialization

Related

• BMB Compiler - Main compiler repository
• VS Code Extension - VS Code support

License

MIT