[whatwg] Control over selection direction

[Marijn Haverbeke]

> If you accept that other selection APIs can't be used in textarea / input,
> then why would you expect your property/method to specify direction can be?

Because I proposed it as *only* working for input fields.

>  Specifically that this direction property/method works for textarea / input
> and other properties/method doesn't is very inconsistent,

This is exactly the situation we have now with the selectionStart and
selectionEnd properties. I'm merely working in the spirit of the
existing situation.