import type { ContextStack } from '../evaluator/ContextStack';
import type { AstNode, BindingTarget } from '../parser/types';
import type { SourceCodeInfo } from '../tokenizer/token';
import type { Builtin } from './interface';
/**
 * Formatting hint stored in Function node payloads.
 * Set at parse time to preserve the shorthand lambda form through formatting.
 */
export interface FunctionHints {
    /** True when authored as shorthand: `-> $ + 1` rather than `($) -> $ + 1`. */
    isShorthand?: boolean;
}
export type Function = [BindingTarget[], AstNode[], FunctionHints?];
export declare function assertNameNotDefined<T>(name: T, contextStack: ContextStack, builtin: Builtin, sourceCodeInfo?: SourceCodeInfo): asserts name is T;