<pre class="language-javascript"><code class="language-javascript">
/**
 * @param {string} str
 * @return {Generator}
 */
function* tokenize(str) {
 str = str.match(/\d+|[\+\-\*\/\(\)]/g).reverse();
 while(str.length){
 // pop is better that shift from time complexity aspect
 yield str.pop();
 }
}</code></pre>

5 Lines Solution with RegExp

> Given a character sequence and a defined document unit, tokenization is the task of chopping it up into pieces, called tokens , perhaps at the same …

120. create `isPrime()`

120. `isPrime()`を実装する