<?php declare(strict_types = 1); namespace TheSeer\Tokenizer; class NamespaceUri { /** @var string */ private $value; public function __construct(string $value) { $this->ensureValidUri($value); $this->value = $value; } public function asString(): string { return $this->value; } private function ensureValidUri($value): void { if (\strpos($value, ':') === false) { throw new NamespaceUriException( \sprintf("Namespace URI '%s' must contain at least one colon", $value) ); } } }