Error Handling

Sun uses error unions for explicit error handling with try/catch blocks.

Error-Returning Functions

Functions declare they may error with , IError suffix:

function divide(a: i32, b: i32) i32, IError {
    if (b == 0) { throw 1; }
    return a / b;
}

Handling Errors with try/catch

Use try/catch to handle potential errors:

function main() i32 {
    try {
        var result = divide(10, 2);
        return result;  // Success: returns 5
    } catch (e: IError) {
        return -1;  // Error path
    }
}

Error Unions

Internally, error-returning functions return an error union struct:

{ i1 isError, T value }

This allows the caller to check if an error occurred and handle it appropriately.

Best Practices

1. Always handle errors: Use try/catch when calling functions that may error
2. Propagate errors: If your function can't handle an error, declare it as error-returning and let the caller handle it
3. Use meaningful error codes: The throw statement accepts an error code that can be checked in the catch block