Exceptions & Error Handling Reference

Kyna features a robust, structured exception model using try, catch, finally, and throw. Both runtime errors and user-thrown exceptions flow through this unified mechanism.

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The Error Object Model

Every exception caught in Kyna exposes standard diagnostic fields:

• code: A machine-readable error code string (e.g., KVM2301, KNET2001, K5100).
• message: A human-readable description of the failure.
• cause: The underlying exception or value, if chained.

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try / catch Blocks

To protect against errors, wrap risky operations in a try block:

try {
    const response = fetch("https://api.kyna.dev/v1/data", { timeout: 3000 });
    const payload = jsonParse(response);
    print("Received payload:", payload);
} catch (err) {
    print("Operation failed!");
    print("Code:", err.code);
    print("Message:", err.message);
}

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The finally Clause

A finally block always executes regardless of whether an exception occurred, was caught, or returned early:

fn processTransaction(): bool {
    var lockAcquired = true;
    print("Acquiring resource lock...");

    try {
        # Risky transactional work
        throw new Error("DB_TIMEOUT", "Database failed to respond within deadline");
        return true;
    } catch (err) {
        print("Caught transaction error:", err.message);
        return false;
    } finally {
        lockAcquired = false;
        print("Resource lock released.");
    }
}

processTransaction();

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Throwing Custom Errors

Use throw with an Error instance or custom message:

fn validateAge(age: int) {
    if (age < 0) {
        throw new Error("VAL1001", "Age cannot be negative: " + age);
    }
    if (age > 150) {
        throw new Error("VAL1002", "Age exceeds plausible threshold: " + age);
    }
}

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Common Compiler & Runtime Error Codes

Code Prefix	Subsystem	Examples
K1000–K1999	Compiler & Static Type Checker	K1001 Unbound variable, K1002 Const reassignment
KVM2000–KVM2999	Virtual Machine Execution	KVM2301 Type cast failure, KVM2302 Division by zero
KNET1000–KNET2999	Networking & HTTP	KNET2001 Connection timeout / DNS failure
K5100	JSON / Serialization	K5100 Malformed JSON parsing error