Asymmetry in movement bindings

There’s a two-by-two of start-end order and word-space order for movement commands:

  • b: end word space start
  • e: start space word end
  • w: start word space end
  • Alt-fSpace: end space word start

But the end space word start command needs three keypresses instead of one. I’m guessing somebody has studied this issue and decided this is right given e.g. the relative frequencies of these operations.

I’m curious what is known about this issue and what design considerations led to the decision. Thanks!

The b, e, and w movement commands are inherited from Vim, so they are defined as they are for historical reasons (I think). The last key sequence you mention, <a-f><space>, is unrelated to b, e, and w, and involves extension to a target character (which you chose to be a space, but could have been anything).