php generators example

old.php

<?php
/**
 * Plugin Name: Paul Test
 */

namespace PaulGibbs;

use Generator;
use WP_Query;

/**
 * A generator for WP_Query/get_posts().
 *
 * @param array $args        Options for WP_Query.
 * @param int   $page_offset Results pagination offset. Passed by reference.
 *
 * @return Generator Yields a result from WP_Query.
 */
function get_many_posts( array $args, int &$page_offset = 0 ) : Generator {
	$query = new WP_Query();

	while ( $page_offset === 1 || $query->paged < $query->max_num_pages ) {
		yield $query->query( array_merge( $args, [ 'paged' => $page_offset ] ) );
		$page_offset++;
	}

	return;
}

add_action(
	'init',

	function() {
		$page = 1;
		$args = [
			'posts_per_page' => 5,
		];

		foreach ( get_many_posts( $args, $page ) as $posts ) {
			echo '<p>Query results:</p><ul>';

			foreach ( $posts as $post ) {
				printf( '<li>ID: %d</li>', $post->ID );
			}

			echo '</ul></p>';
		}

		die;
	}
);