CompoundID.php

<?php
declare(strict_types=1);

namespace PrinsFrank\Transliteration\Syntax\FormalId;

use PrinsFrank\Transliteration\Syntax\Enum\Literal;
use PrinsFrank\Transliteration\Exception\InvalidArgumentException;
use PrinsFrank\Transliteration\Syntax\FormalId\Components\Filter;

/**
 * @internal
 *
 * @see https://unicode-org.github.io/icu/userguide/transforms/general/#formal-id-syntax
 */
final class CompoundID implements ID
{
    /**
     * @param list<SingleID> $singleIds
     * @throws InvalidArgumentException
     */
    public function __construct(
        public readonly array       $singleIds,
        public readonly Filter|null $globalFilter = null,
    ) {
        foreach ($this->singleIds as $singleId) {
            $singleId instanceof SingleID === true || throw new InvalidArgumentException('Param $singleIds should be an array of "' . SingleID::class . '"');
        }
    }

    public function __toString()
    {
        $string = '';
        if ($this->globalFilter !== null) {
            $string .= $this->globalFilter->__toString() . Literal::Semicolon->value;
        }

        foreach ($this->singleIds as $singleId) {
            $string .= $singleId->__toString() . Literal::Semicolon->value;
        }

        return $string;
    }
}