just compile it from Git

Hi, I’m wondering if I could use +nan.0 or -0.0 to represent a missing value in a (Array Flonum+missing) type. Is that ok, or will it conflict too much with the language (if Racket computations often yield or use +nan.0 or -0.0)?

You can use the undefined constant. It is only eq? to itself. https://docs.racket-lang.org/reference/undefined.html\|https://docs.racket-lang.org/reference/undefined.html

Thanks, I did not know about that!

You could also use #false, it’s pretty common in racket code to see values of the type “the thing you’re expecting or else false”