What Beans is

Beans is a small, general-purpose programming language with explicit types, predictable ownership, and direct systems access.

It supports standalone functions and closures, structs and enums, and classes with interfaces and inheritance. Structs copy by value; classes have reference semantics. You can write a complete program with functions, without defining a class.

Source files end in .b.

Types, arithmetic, and errors

• Mandatory explicit types. Declarations state their types.
• Exact decimal arithmetic. Base-10 arithmetic gives 19.99 * 3 as 59.97 exactly.
• No null and no exceptions. Missing values use Option<T>; failures use Result<T>.

Memory and systems access

• Sized integers like i32 and u64, and value types (struct, union).
• An unsafe layer with raw memory and C interop.
• Automatic memory management. Memory uses automatic reference counting with a cycle collector, rather than a tracing garbage collector.

One tool: beansc

There is a single command, beansc, and it is the whole toolchain:

• a type checker that verifies your program,
• a reference interpreter that runs it with no build step,
• a native LLVM backend that compiles it to a real binary,
• a package manager (beansc pot),
• a language server (LSP) for editors, and
• a debugger (DAP).

beansc is self-hosted: the Beans compiler is written in Beans and compiles itself.

A tiny example

Here is a complete Beans program. Save it as hello.b.

import std.io

fn main() {
    let name: string = "beans"
    io.println("hello from {name}")
}

{name} inside the string is interpolation: it prints the value of name. Run it with:

beansc run hello.b

hello from beans

Next, read the language philosophy for the rules behind these choices, or install Beans and run your first program.