Example 6-22. Throwing errors with the iterator

function* languages() {
	try {
		yield 'English';
		yield 'French';
		yield 'German';
		yield 'Spanish';
	} catch (error) {
		console.log(error.message);
	}
}

var greetings = {
	English: 'Hello',
	French: 'Bonjour',
	Spanish: 'Hola'
};

var iterator = languages();
var result;
var word;

while ((result = iterator.next()).done !== true) {
	word = greetings[result.value];
	if (word) console.log(word);
	else iterator.throw(Error('Missing translation for ' + result.value));
}

// Console output:
// Hello
// Bonjour
// Missing translation for German