<?php

namespace Arma\Internal;

use Arma\ {
    MapVal,
    SvCol, SvRow, SvMat,
    DiagView
};

/**
 * Interface for dense matrices.
 *
 * @package Arma
 */
interface DenseMatrix extends Dense, Matrix
{
    // Subview

    /**
     * {@inheritdoc}
     *
     * @param int $i
     * @param int $j[optional]
     * @return MapVal
     */
    function __invoke($i, $j);

    /**
     * {@inheritdoc}
     *
     * @param int $i
     * @param int $j[optional]
     * @return MapVal
     */
    function at($i, $j);

    /**
     * {@inheritdoc}
     *
     * @param int $col_number
     * @return SvCol
     */
    function col($col_number);

    /**
     * {@inheritdoc}
     *
     * @param int $row_number
     * @return SvRow
     */
    function row($row_number);

    /**
     * {@inheritdoc}
     *
     * @param int $first_col
     * @param int $last_col
     * @return SvMat
     */
    function cols($first_col, $last_col);

    /**
     * {@inheritdoc}
     *
     * @param int $first_row
     * @param int $last_row
     * @return SvMat
     */
    function rows($first_row, $last_row);

    /**
     * {@inheritdoc}
     *
     * @param int $first_row
     * @param int $first_col
     * @param int $last_row
     * @param int $last_col
     * @return SvMat
     */
    function submat($first_row, $first_col, $last_row, $last_col);

    /**
     * {@inheritdoc}
     *
     * @param int $k[optional]
     * @return DiagView
     */
    function diag($k = 0);

    // Iteration

    /**
     * Apply a callback function to each row of the matrix.
     *
     * @param callable $action (SvRow) -> void
     * @return void
     */
    function eachRow($action);

    /**
     * Apply a callback function to each column of the matrix.
     *
     * @param callable $action (SvCol) -> void
     * @return void
     */
    function eachCol($action);

    // Transform

    /**
     * Returns an inverse of the matrix.
     *
     * If matrix is know to be symmetric positive definite, it's faster when $inv_sympd is true.
     *
     * @param bool $inv_sympd[optional]
     * @return DenseMatrix
     */
    function i($inv_sympd = false);

    /**
     * Check whether the matrix is symmetric/hermitian positive definite within the tolerance given by $tol.
     *
     * @param number $tol[optional]
     * @return bool
     */
    function isSympd($tol);
}