Introduction

Bnlang is a dual-language programming language and runtime. You can write the same program in English or Bangla — the parser maps both keyword sets to the same syntax tree, so the language itself is a single, predictable thing.

Bnlang is native: a tree-walking interpreter written in modern C++ with a libuv event loop. There is no transpilation step and no JavaScript engine — bnl runs your .bnl file directly.

Design principles

Predictable semantics. Small, regular syntax. Fixed-arity functions. No surprising overloads, no implicit type coercions worth memorizing.
One way to do it. No let/const/var trio — just var. No === and == debate — just ==. No null and undefined split — just null.
Batteries included. File I/O, HTTP/WebSocket server and client, templating, SQLite/PostgreSQL/MySQL/MongoDB, crypto, timers, JSON, regex — all in the standard library.
Extensible. Drop a .dll / .so / .dylib next to a bnl.json and import it like any other module. Plugins use a single drop-in C header — they can be written in C, C++, Rust, Go, Zig, or anything with a C ABI.

Runtime stack (under the hood)

C++20 — the interpreter, value model, and every built-in module.
libuv — cross-platform event loop and async I/O primitives.
OpenSSL — TLS for HTTPS / WebSocket-over-TLS, plus hashing, HMAC, base64/hex codecs.
llhttp — fast HTTP/1.1 parser used by the built-in web server and client.
SQLite / libpq / libmariadb / mongo-c-driver — embedded SQLite and first-class clients for PostgreSQL, MySQL/MariaDB, MongoDB.
zlib — gzip/deflate.

Hello, Bnlang (two ways)

// English
print("Hello, Bnlang!");

// Bangla
লিখুন("হ্যালো, Bnlang!");

Both produce the same output. The lexer maps print and লিখুন to the same built-in.

Installation

Download the latest binary for your platform from the Releases page — Windows (.exe / .zip), Linux (.tar.gz), macOS (.pkg / .tar.gz).
Make sure bnl is on your PATH.
Verify:

bnl --version
# Bnlang (bnl) 1.0.0 (windows)

Project layout

my-app/
  ├─ src/
  │  └─ main.bnl
  ├─ bnl.json        # project manifest (managed by bpm)
  ├─ bnl.lock        # lockfile (generated)
  └─ deps/           # installed packages

Versioning and docs

Versions follow vMAJOR.MINOR.PATCH. Docs are versioned at /docs/v1.0.0/... with English and Bangla locales.