Middle.Fun_kindTypes for function kinds, e.g. StanLib or UserDefined, and function suffix types, e.g. foo_ldfp, bar_lp
val sexp_of_propto : propto -> Sexplib0.Sexp.tval sexp_of_support : support -> Sexplib0.Sexp.tval sexp_of_suffix : suffix -> Sexplib0.Sexp.ttype 'e t = | StanLib of string * suffix| Operator of Operator.t| CompilerInternal of 'e Internal_fun.t| UserDefined of string * suffixval sexp_of_t : 'e. ('e -> Sexplib0.Sexp.t) -> 'e t -> Sexplib0.Sexp.tval fold : ('a -> 'b -> 'a) -> 'a -> 'b t -> 'aval suffix_from_name : string -> suffixval pp : 'a Fmt.t -> Stdlib.Format.formatter -> 'a t -> unitval collect_exprs : 'a t -> 'a list