Error

The Error class is globally available — no import is needed. It provides structured error objects with a message, optional error code, and optional data payload.

Creating Errors

// Simple error with a message
throw new Error("something went wrong");

// Error with a code
throw new Error("not found", 404);

// Error with a code and additional data
throw new Error("validation failed", "VALIDATION_ERROR", { "field": "age" });

Properties

Property	Type	Description
`message`	`string`	The error message (required)
`code`	`any`	Optional error code (e.g. `404`, `"NOT_FOUND"`)
`data`	`any`	Optional additional data
`stack`	`string`	Stack trace (reserved for future use)

Methods

`toString(): string`

Returns a string representation of the error.

const err = new Error("file not found", 404);
println(err.toString()); // "Error: file not found"

Error Handling with try/catch

function divide(a: int, b: int): int {
    if (b == 0) {
        throw new Error("division by zero", "MATH_ERROR");
    }
    return a / b;
}

function main() {
    try {
        const result = divide(10, 0);
        println(result);
    } catch (e) {
        println(e.message); // "division by zero"
        println(e.code);    // "MATH_ERROR"
    }
}

Custom Error Patterns

Since code and data are flexible, you can build rich error objects:

// HTTP-style errors
throw new Error("Unauthorized", 401, { "required": "Bearer token" });

// Validation errors with field details
throw new Error("Invalid input", "VALIDATION", {
    "field": "email",
    "reason": "must be a valid email address"
});

Checking Error Properties

try {
    // ... something that might fail
} catch (e) {
    if (e.code == 404) {
        println("Not found: " + e.message);
    } else if (e.code == "VALIDATION") {
        println("Validation error in field: " + e.data["field"]);
    } else {
        println("Unexpected error: " + e.toString());
    }
}