`$.` could default to `$.0`

[randomra]

E.g. using

.+
$.

instead of

.+
$.0

[m-ender]

I'll think about it. I don't want to go too overboard with these shorthands, but this one seems useful.

[m-ender]

For your specific example it's shorter to do M`. though, or M%`. if there can be multiple lines in the input.