Formatter Rules

braid-fmt Tool

The braid-fmt tool automatically formats Braid source code according to the canonical style. Run it on any .br or .bd file:

braid-fmt source.br        # Print formatted to stdout
braid-fmt source.br -i     # Format in-place
braid-fmt --check src/     # Check formatting (exit 1 if unformatted)

Formatting Rules

Indentation: 4 Spaces

Use 4 spaces per indentation level. No tabs. This matches the C codegen output in CCodegen.cpp:

std::string CCodegen::indent() const {
    return std::string(indent_ * 4, ' ');
}

Brace Placement: Same-Line (K&R Style)

Opening braces go on the same line as the declaration or statement. Closing braces are on their own line:

fn main() {
    let x = 10;
    if x > 5 {
        print("greater");
    } else {
        print("less or equal");
    }
}

Semicolons Required

Statement-ending semicolons are mandatory. The parser expects them after expression statements, variable declarations, and return statements:

// ✓ Correct
let x = 10;
x = x + 1;
return x;

// ✗ Incorrect - missing semicolons
let x = 10
x = x + 1
return x

Spacing Around Operators

Binary operators must have a single space on each side:

// ✓ Correct
let sum = a + b;
let eq = x == y;
let cond = a && b;

// ✗ Incorrect
let sum = a+b;
let eq = x==y;
let cond = a&&b;

Other Rules

• No trailing whitespace at end of lines
• One blank line between function definitions
• Commas in struct literals and function calls followed by a space: fn(a, b, c)
• No space before parentheses in function calls: foo(), not foo ()
• Type annotations use a single space after the colon: x: int

Example: Formatted vs Unformatted

Unformatted:

fn   add(x:int,y:int)->int{
return x+y;
}
let   values=[1,2,3];

Formatted:

fn add(x: int, y: int) -> int {
    return x + y;
}

let values = [1, 2, 3];