[whatwg] Control over selection direction

> If you don't need the TextRange-like character-based modification, you
> can instead use the selection's extend() method (supported in Mozilla,
> WebKit and Opera for years) to create a backwards selection:

Maybe that is what you meant by this not working for TextRange-like
things, but, unfortunately, the regular selection primitives do not
appear to treat the content of text input and textarea elements as
separate elements. I can use this trick to create a reversed selection
that starts at the start of the textarea, but not one starting at an
arbitrary character.