vi is very handy when doing a lot of config file editing and can save you time over using the mouse or using the x or delete keys to manually delete.
Solution:
If you don't want it to stop deleting when encountering things like - or _, then you want this:
d$
Or if you want it to stop on - and _ then use this:
dw
Remember both commands are in "non-input mode" so not when you're........