Fusion Lang

A toy language to continue learning antlr4 and mlir/llvm and see where I go

Setting up environment

If you are on macos then I have made a simple install script which will install all requirements/dependencies needed to develop with antlr and mlir, located here

Building

mkdir build
cd build
cmake ..
make

Running

cd bin
./fuse <filename>.fuse

Documentation

Declarations

The let keyword signifies that the variable can be later changed. The const keyword signifies that the variable cannot be later changed;

let x: i32 = 5;
const y: i32 = x;

Types

• i32: 32-bit integer
• i64: 64-bit integer
• ch: 8-bit ascii character
• bool: 1-bit boolean(true/false)

Functions

fn foo(let x: i32, let y: ch): i32 {
    print(x);
    print(y);

    return x + 1;
}

fn main(): i32 {
    foo(5, '\n');
    return 0;
}

Builtin Functions

main

Must be defined by the user, is the entry point to the fusion program

fn main(): i32 {
    // do stuff
    return 0;
}

print

Prints the argument passed to stdout

print(5);

println

Prints the argument passed to stdout with a newline at the end

println(100);

Arithmetic

• addition: +
• subtraction: -
• power: ^
• multiplication: *
• division: /
• modulus: %
• greater than(eq): >, >=
• less than(eq): <, <=
• equal: ==
• not equal: !=
• and: &&
• or: ||

fn main(): i32 {
    let a: i32 = 5 + 5;
    let s: i32 = 5 - 5;
    let p: i32 = 5 ^ 5;
    let m: i32 = 5 * 5;
    let d: i32 = 5 / 5;
    let r: i32 = 5 % 5;

    let gt: bool = 5 > 4;
    let lt: bool = 4 < 5;
    let gte: bool = 5 >= 5;
    let lte: bool = 5 >= 5;
    let eq: bool = 5 == 5;
    let ne: bool = 5 != 5;
    let o: bool = 5 != 5 || 5 == 5;
    let a: bool = 5 != 5 && 5 == 5;
}

Conditionals

Just like if/else statements in most languages

let x: i32 = 5;
if(x == 4){
    println(0);
} else if(x == 5) {
    println(10);
} else {
    println(x);
}

Conditions must be booleans

Loops

Similar to c-style for loops, they are composed of 4 parts

• Variable declaration
• Loop condition
• Variable assignment
• Body

for(let i: i32 = 0; i < 5; i = i + 1){
    println(i);
}

Loops also allow for control flow:

• continue: goes to the next iteration of the loop
• break: exits the loop early