Unicode mathematical notation using `conceal`
Inspired by (and based on) vim-cute-python.
After enabling g:coffee_cute, certain keywords are replaced with their equivalent mathematical notation (such as ∈, ∧ and ∨) and function arrows are converted to unicode as well.
CoffeeScript is pretty terse already, so I doubt anyone will use this, but it's a nice showcase of conceal, don't you think?
I like it, other than the places that have provisions for is not, which is not a special production in CoffeeScript. Those should be removed.
Related: jashkenas/coffee-script#1679
I think this is a great feature. I use and contribute to vim-cute-python. But in the interests of separating code, I think this should be a distinct vim plugin.