Problem :
E.g. Alt-d deletes word until next word boundary. There’s also a shortcut to delete until previous word boundary IIRC, but I’d like to delete word UNDER cursor (i.e. to current word left boundary and next word boundary).
Is this even available in readline?
Solution :
OK found it: you can create key bindings to “macros”: http://manpages.ubuntu.com/manpages/trusty/en/man3/readline.3readline.html
First, choose a key combination you want to use for this “kill whole word” operation — peruse bind -sp | sort | less to see what’s in use.
Suppose Ctrl-xCtrl-w is OK, then
echo '"C-xC-w": "edeC-h"' >> ~/.inputrc
Start a new shell, and you should be good to go.
Although Ctrl-xCtrl-w is just as easy/awkward as Alt-dAlt-Backspace