title: how to predict if DOM keydown will cause a character input
body: <p>Given a <code>keydown</code> event in the browser, how can I predict whether that key event will result in character input? For example, hitting the left arrow doesn't input characters but hitting the <kbd>a</kbd> key inputs an A (unless <kbd>ctrl</kbd> or <kbd>alt</kbd> is down).</p>
  
  <p>I don't need to know what character will be input, just whether the key event will result in an input.</p>
  
  <p>I'm targeting Chrome. Bonus points if your solution works in an IME.</p>
  
  <p>Note: I'm asking about the <code>keydown</code> event, not a downstream event like <code>keypress</code> or <code>oninput</code>.</p>