/**
 * Control Flow Signals
 *
 * Signals thrown to unwind the call stack for control flow.
 * These are part of the public API for host applications that
 * need to catch and handle control flow.
 */
import type { RillValue } from './types/structures.js';
/**
 * Abstract base for all control-flow signals.
 * Subclasses pass their name and message to the protected constructor.
 * Never instantiated directly.
 */
export declare abstract class ControlSignal extends Error {
    readonly value: RillValue;
    protected constructor(name: string, message: string, value: RillValue);
}
/** Signal thrown by `break` to exit loops */
export declare class BreakSignal extends ControlSignal {
    constructor(value: RillValue);
}
/** Signal thrown by `return` to exit blocks */
export declare class ReturnSignal extends ControlSignal {
    constructor(value: RillValue);
}
/** Signal thrown when a stream yields a chunk value */
export declare class YieldSignal extends ControlSignal {
    constructor(value: RillValue);
}