Un-Expand/Shrink word-wise selection and navigation in mark mode

[golk (groutoutlook)]

as I want a way to map other key that do the same thing as a ctrl+left when selecting in map mode.

as I already map my expandSelectionToWord to w, I hope there is a chance shrinkSelectionByWord (name suggestion, dont mind me here) can be remapped to b or something quite similar in that manner. ctrl+left hurt my pinky.

Vim-like keybind inspired.

PS. there is another case of user swap selection anchor position, in that case I really meant expanding selection by left direction.

but actually right now only ctrl+ work so I hope this can be implemented to be remappable.