Automattic\WooCommerce\Vendor\GraphQL\Utils

LexicalDistance::measure │ public │ WC 1.0

Method of the class: LexicalDistance{}

No Hooks.

Returns

null. Nothing (null).

Usage

$LexicalDistance = new LexicalDistance();
$LexicalDistance->measure( $option, $threshold ): ?int;

$option(string) (required)

.

$threshold(float) (required)

.

LexicalDistance::measure() LexicalDistance::measure code ^{WC 10.9.1}

public function measure(string $option, float $threshold): ?int
{
    if ($this->input === $option) {
        return 0;
    }

    $optionLowerCase = strtolower($option);

    // Any case change counts as a single edit
    if ($this->inputLowerCase === $optionLowerCase) {
        return 1;
    }

    $a = self::stringToArray($optionLowerCase);
    $b = $this->inputArray;

    if (count($a) < count($b)) {
        $tmp = $a;
        $a = $b;
        $b = $tmp;
    }

    $aLength = count($a);
    $bLength = count($b);

    if ($aLength - $bLength > $threshold) {
        return null;
    }

    /** @var array<array<int>> $rows */
    $rows = [];
    for ($i = 0; $i <= $bLength; ++$i) {
        $rows[0][$i] = $i;
    }

    for ($i = 1; $i <= $aLength; ++$i) {
        $upRow = &$rows[($i - 1) % 3];
        $currentRow = &$rows[$i % 3];

        $smallestCell = ($currentRow[0] = $i);
        for ($j = 1; $j <= $bLength; ++$j) {
            $cost = $a[$i - 1] === $b[$j - 1] ? 0 : 1;

            $currentCell = min(
                $upRow[$j] + 1, // delete
                $currentRow[$j - 1] + 1, // insert
                $upRow[$j - 1] + $cost, // substitute
            );

            if ($i > 1 && $j > 1 && $a[$i - 1] === $b[$j - 2] && $a[$i - 2] === $b[$j - 1]) {
                // transposition
                $doubleDiagonalCell = $rows[($i - 2) % 3][$j - 2];
                $currentCell = min($currentCell, $doubleDiagonalCell + 1);
            }

            if ($currentCell < $smallestCell) {
                $smallestCell = $currentCell;
            }

            $currentRow[$j] = $currentCell;
        }

        // Early exit, since distance can't go smaller than smallest element of the previous row.
        if ($smallestCell > $threshold) {
            return null;
        }
    }

    $distance = $rows[$aLength % 3][$bLength];

    return $distance <= $threshold ? $distance : null;
}