Use suin/json's encoder in JsonMarshaller.

[suin]

Unmarshalling uses suin/json's decoder.

php-marshaller/src/JsonMarshaller.php

Lines 40 to 48 in 1d984eb

	/**
	* @param mixed $data
	* @param string $typeExpression
	* @return array|object
	*/
	public function unmarshal($data, string $typeExpression)
	{
	return (new ConstructorUnmarshaller($this->protocol))->unmarshal($this->decoder->decode($data), $typeExpression);
	}

On the other hand, marshalling does not.

php-marshaller/src/JsonMarshaller.php

Lines 30 to 38 in 1d984eb

	/**
	* @param array|object $value
	* @param int $options
	* @return mixed
	*/
	public function marshal($value, $options = 0)
	{
	return json_encode((new Marshaller($this->protocol))->marshall($value), $options);
	}

Since suin/json's encoder throws exceptions, it would be safer than built-in function, when some errors occur.