I like that a lot, but the `to` syntax bugs me. Why not a colon, or Scala's `->`?

You type "->" faster and easier then "to"?

No, but it's visually clearer to me at a glance. It feels weird using letters, let alone full English words, to describe a mapping or anything else that I think a symbol is more suited for.

To me it would feel like assigning a variable with:

   a equals 6
   n equals "A"

Just feels icky, somehow.

Again, that wouldn't dissuade me from using the language whatsoever. It's only a minor irritation.

Because "to" isn't actually syntax at all. It's an infix function that creates a Pair. You can alt-click it in the IDE to go to the definition.

`->` in Scala is also just a method, but I think it's fair to call such things syntax even if they're not true "baked-in" language syntax.