Which values may be map keys (DXN.md §1.6): a string, keyword,
integer, uuid, objectid, date, bytes, symbol or char. Anything else is
refused as key/not-allowed -- in text, in binary and when encoding.
The allowed types are those whose identity is exact and obvious in
every language: two keys are the same exactly when their canonical
forms are. Floats, decimals and rationals are not (1 against 1.0,
0.0 against -0.0, 1.0M against 1.00M); neither are times, URIs
or collections; nil and the booleans collide with other keys in some
languages and are rare as keys anyway.
Judged by value, with one thing a value cannot say. NaN and the
infinities are the atoms :nan, :positive_infinity and
:negative_infinity here, which is also what the keywords of those
names decode to. So an atom is allowed as a keyword, and the readers
refuse a float key by what it was written as: the text decoder by its
token, the binary decoder by its CBOR major type.
Summary
Functions
:ok when key may be a map key, or a key/not-allowed error naming
it.
:ok when every key of pairs may be a map key, or the first refusal.
The error for a key that is not allowed, naming it as Dextrin.encode/2
writes it, or as Elixir does when DXN cannot write it.
Functions
@spec check(term()) :: :ok | {:error, Dextrin.Error.t()}
:ok when key may be a map key, or a key/not-allowed error naming
it.
Dextrin.MapKey.check("a") #=> :ok
Dextrin.MapKey.check(1.5) #=> {:error, %Dextrin.Error{category: "key/not-allowed", ...}}@spec check_pairs([{term(), term()}]) :: :ok | {:error, Dextrin.Error.t()}
:ok when every key of pairs may be a map key, or the first refusal.
@spec refusal(term()) :: Dextrin.Error.t()
The error for a key that is not allowed, naming it as Dextrin.encode/2
writes it, or as Elixir does when DXN cannot write it.