('key, 'value, cmp) Map.t where every value of type
'key is present.
This is intended to be used on
'key types where there is a full enumeration of the
type. In the common use case,
'key will be a simple variant type with
compare, enumerate]. For example:
module Arrow_key = struct module T = struct type t = | Up | Down | Left | Right [@@deriving sexp, bin_io, compare, enumerate] end include T module Total_map = Total_map.Make (T) end
In such a case, a
t is semantically equivalent to a pure function from
'value. The differences are that it is serializable and that mapping or changing a
t will produce a
t using the same amount of space as the original.
However, in theory you could also modify the comparison function and enumeration, so long as the enumeration contains at least one representative of each equivalence class determined by the comparison function.
Many of the functions below have types reflecting the fact that the maps are total
find does not return an option). The fact that they won't raise exceptions
relies on the enumeration passed to
Make being complete.
The only reason that the Applicative interface isn't included here is that we don't