Haydnで結果に含めるかどうかを行ごとにオンデマンドで判定する

.gitignore

vendor/
composer.lock

composer.json

{
    "name": "hidenorigoto/haydn-select-returnnull",
    "authors": [
        {
            "name": "hidenorigoto",
            "email": "hidenorigoto@gmail.com"
        }
    ],
    "require": {
        "quartet/haydn": "^1.3"
    }
}

test.php

<?php
require_once __DIR__.'/vendor/autoload.php';

$data = [
    ['name' => 'りんご', 'available' => true],
    ['name' => 'バナナ', 'available' => false],
    ['name' => 'みかん', 'available' => true],
];

$set = new \Quartet\Haydn\Set(new \Quartet\Haydn\IO\Source\ArraySource('fruit', $data, new \Quartet\Haydn\IO\ColumnMapper\HashKeyColumnMapper()));

$set = new \Quartet\Haydn\Set\GroupingSet($set,
    null,
    function($row) {
        return $row['available'] ?
            new \Quartet\Haydn\Set(new \Quartet\Haydn\IO\Source\SingleRowSource('fruit', $row)) :
            new \Quartet\Haydn\Set\EmptySet();
    },
    null
);

$result = $set->toArray();
var_dump($result);