Foldable.Basic
The Basic
definition for type constructors with a single type variable.
This signature just says that you have some type 'a t
and a function fold
with type:
fold: ('b -> 'a -> 'b) -> 'b -> 'a t -> 'b
This function can be derived using ppx_deriving
.
val fold : ('b -> 'a -> 'b) -> 'b -> 'a t -> 'b