title: How to parse & process mathematical expressions in JavaScript Calculator?
body: <p>Whats the best approach with javascript to evaluate an expression like <code>3+1*sin(20)*e^3</code>?</p>
  
  <p>First of all, I do not want to use built-in math-functions. In fact, I have already defined my own functions for <code>power</code>, <code>square root</code>, <code>sin</code>, <code>cos</code>, <code>exponential</code>, etc.</p>
  
  <p>What I'm looking for, is a good way to parse an expression so I can pass them to these functions I created. I know there is an <code>eval()</code> function available in JavaScript for evaluating input expressions, but I'm not sure if that's suitable for this context.</p>
  
  <p>Should I use <code>eval()</code>? If yes, how do I use it in this context? If no, what's a more suitable way to parse mathematical expressions?!
  It's not an school assignment, its just a doubt.</p>