function Differ::coalesceReplacements

Same name in this branch

11.1.x vendor/phpstan/phpdoc-parser/src/Printer/Differ.php \PHPStan\PhpDocParser\Printer\Differ::coalesceReplacements()

Coalesce equal-length sequences of remove+add into a replace operation.

Parameters

DiffElem[] $diff:

Return value

DiffElem[]

1 call to Differ::coalesceReplacements()

Differ::diffWithReplacements in vendor/nikic/php-parser/lib/PhpParser/Internal/Differ.php: Calculate diff, including "replace" operations.

File

vendor/nikic/php-parser/lib/PhpParser/Internal/Differ.php, line 142

Class

Differ: Implements the Myers diff algorithm.

Namespace

PhpParser\Internal

Code

private function coalesceReplacements(array $diff) : array {
    $newDiff = [];
    $c = \count($diff);
    for ($i = 0; $i < $c; $i++) {
        $diffType = $diff[$i]->type;
        if ($diffType !== DiffElem::TYPE_REMOVE) {
            $newDiff[] = $diff[$i];
            continue;
        }
        $j = $i;
        while ($j < $c && $diff[$j]->type === DiffElem::TYPE_REMOVE) {
            $j++;
        }
        $k = $j;
        while ($k < $c && $diff[$k]->type === DiffElem::TYPE_ADD) {
            $k++;
        }
        if ($j - $i === $k - $j) {
            $len = $j - $i;
            for ($n = 0; $n < $len; $n++) {
                $newDiff[] = new DiffElem(DiffElem::TYPE_REPLACE, $diff[$i + $n]->old, $diff[$j + $n]->new);
            }
        }
        else {
            for (; $i < $k; $i++) {
                $newDiff[] = $diff[$i];
            }
        }
        $i = $k - 1;
    }
    return $newDiff;
}