import { QueryNode } from './base';
/**
 * A query that evaluates to true if a value is of a certain type, or false otherwise
 */
export declare class TypeCheckQueryNode extends QueryNode {
    readonly valueNode: QueryNode;
    type: BasicType;
    constructor(valueNode: QueryNode, type: BasicType);
    private describeType;
    describe(): string;
}
export declare enum BasicType {
    OBJECT = 0,
    LIST = 1,
    SCALAR = 2,
    /**
     * The single NULL type (note that there is nothing like undefined - missing properties should evaluate to NULL)
     */
    NULL = 3
}
/**
 * A query node that evaluates to node if it's a list, or to an empty list if it's not
 *
 * This could be reduced to a conditional node and a TypeCheck node, but it eases database-specific optimizations
 */
export declare class SafeListQueryNode extends QueryNode {
    readonly sourceNode: QueryNode;
    constructor(sourceNode: QueryNode);
    describe(): string;
}