Introducing the Buffer instance

[nyamsprod]

The League\Csv\Buffer class enables doing the following:

use League\Csv\Buffer;
use League\Csv\Query\Constraint\Column;
use League\Csv\Reader;
use League\Csv\Writer;

$csv = <<<CSV
rating,title,author,type,asin,tags,review
...
...
CSV;

$document = Reader::createFromString($csv);
$document->setHeaderOffset(0);

$buffer = Buffer::from($document->slice(0, 50));
$buffer->delete(Column::filterOn('rating', '=', ''));
$buffer->update(Column::filterOn('tags', '=', ''), ['tags' => 'book sci-fi']);
$buffer->insertOne([
    'rating' => 3,
    'author' => 'Echiro Oda',
    'title' => 'One Piece',
    'type' => 'Manga',
    'asin' => '000254123',
    'tags' => 'book manga sci-fi shonen  fights pirates',
    'review' => 'still need to read at least 1100 chapters before making my mind.',
]);

$newDocument = Writer::createFromString();
$newDocument->setDelimiter(";");
$newDocument->forceEnclosure();
$buffer->to($newDocument);

echo $newDocument->toString(), PHP_EOL;

//display

rating,title,author,type,asin,tags,review
...
...
"3";"One Piece";"Echiro Oda";"Manga";"000254123";"book manga sci-fi shonen  fights pirates";"still need to read at least 1100 chapters before making my mind."