/**
 * @license
 * Copyright (c) 2025 Handsoncode. All rights reserved.
 */
import { ProcedureAst } from '../../parser';
import { InterpreterState } from '../InterpreterState';
import { InterpreterValue } from '../InterpreterValue';
import { FunctionPlugin, FunctionPluginTypecheck, ImplementedFunctions } from './FunctionPlugin';
/**
 * Interpreter plugin for percentile and quartile statistical functions.
 *
 * Implements inclusive (INC) and exclusive (EXC) interpolation variants.
 * QUARTILE functions delegate to PERCENTILE by converting quart index to
 * a percentile fraction (quart / 4) after truncating to integer.
 */
export declare class PercentilePlugin extends FunctionPlugin implements FunctionPluginTypecheck<PercentilePlugin> {
    static implementedFunctions: ImplementedFunctions;
    static aliases: {
        PERCENTILE: string;
        QUARTILE: string;
    };
    /**
     * Corresponds to PERCENTILE(array, k) and PERCENTILE.INC(array, k).
     *
     * Returns the k-th percentile of values in a range using inclusive interpolation.
     *
     * @param ast - procedure AST node
     * @param state - interpreter state
     * @returns interpolated percentile value, or CellError on invalid input
     */
    percentile(ast: ProcedureAst, state: InterpreterState): InterpreterValue;
    /**
     * Corresponds to PERCENTILE.EXC(array, k).
     *
     * Returns the k-th percentile of values in a range using exclusive interpolation.
     *
     * @param ast - procedure AST node
     * @param state - interpreter state
     * @returns interpolated percentile value, or CellError on invalid input
     */
    percentileExc(ast: ProcedureAst, state: InterpreterState): InterpreterValue;
    /**
     * Corresponds to QUARTILE(array, quart) and QUARTILE.INC(array, quart).
     *
     * Returns the quartile of a data set using inclusive interpolation.
     * quart is truncated to an integer and validated in [0, 4].
     *
     * @param ast - procedure AST node
     * @param state - interpreter state
     * @returns quartile value, or CellError on invalid input
     */
    quartile(ast: ProcedureAst, state: InterpreterState): InterpreterValue;
    /**
     * Corresponds to QUARTILE.EXC(array, quart).
     *
     * Returns the quartile of a data set using exclusive interpolation.
     * quart is truncated to an integer and validated in [1, 3].
     *
     * @param ast - procedure AST node
     * @param state - interpreter state
     * @returns quartile value, or CellError on invalid input
     */
    quartileExc(ast: ProcedureAst, state: InterpreterState): InterpreterValue;
    /**
     * Extracts numeric values from a range, filters non-numbers, and returns them sorted.
     * Returns CellError if the range contains an error, or if no numeric values exist.
     *
     * @param range - input range from the spreadsheet
     * @returns sorted numeric values (ascending), or CellError
     */
    private getSortedValues;
}