import type { RuntimeContext } from '../types/runtime.js';
import type { TypeStructure, RillValue, RillStream } from '../types/structures.js';
import type { StreamChannel } from './invocation/stream-closures.js';
import type { CallableInvocationStrategy } from './invocation/callable-strategy.js';
/**
 * EvalState — the shared evaluation state threaded through all module-level
 * eval functions.
 *
 * Concrete data shape (no methods): `ctx` plus the per-context mutable
 * fields formerly held on the composed Evaluator instance.
 */
export interface EvalState {
    ctx: RuntimeContext;
    activeStreamChannel: (StreamChannel & {
        readonly resolution: RillValue;
    }) | null;
    activeStreamChunkType: TypeStructure | null;
    streamScopeStack: RillStream[][];
    invocationStrategy: CallableInvocationStrategy | undefined;
}
/**
 * Get or create the EvalState for a given RuntimeContext.
 *
 * EvalState instances are cached per context to avoid recreating the same
 * state multiple times during script execution.
 *
 * @param ctx - The runtime context
 * @returns EvalState (cached or newly created)
 *
 * @internal — not exported from packages/core/src/index.ts.
 */
export declare function getEvalState(ctx: RuntimeContext): EvalState;