Crosscut

This is roughly how you define a function in Crosscut:

fn
    _  # parameter
    {} # body

(I say "roughly", because parameters aren't fully implemented yet, and _ isn't a valid placeholder for one. And {} is not yet valid syntax for an empty body that returns nothing. It's a work in progress, but this should suffice as an example.)

This should work great with restricted structural editing. You type fn, and the placeholders for parameter and body are added automatically. You navigate down to edit the parameter, and further down to edit the body. Then you continue on, in the same direction, to whatever you add next.

It wouldn't be quite as smooth with postfix syntax. Tomorrow, let's take a look at that.