choose-arbitrary

[jackfirth]

I wanted a simple arbitrary-datum, which would be an arbitrary atomic Racket datum, such as:

• A number
• A character
• A symbol
• A boolean

It would be nice if there was a choose-arbitrary function that accepted a variable number of arbitrary? instances and returned an arbitrary? that produced values from one of them. I don't know how that interacts with the trans narrowing filter functions though.