Trying to use match in type Racket, I wonder if there is a match pattern that can test the type of a value?
If I have define a type Frummich, is there a math pattern I can use to tell whether value being matched is in fact a valueof type Frummich?
Racket and Scheme don't have a way to ask a value what type it is (unlike Common Lisp), just allowing asking if a value is of a specific type via an appropriate predicate function. So if you have a frummich? function you can branch off of it (See the Typed Racket Guide entry on propositions and predicates for how to write ones that interact with the TR type system):
(match foo
[(? frummich? frum) ...]
; etc
)