@spec base_unit_order() :: [String.t()]

Returns the canonical ordering of base units from unitQuantities.

This ordering is used to reconstruct canonical base unit strings.

Returns

• A list of base unit strings in canonical order.

@spec base_unit_to_quantity() :: %{required(String.t()) => String.t()}

Returns a map from base unit string to its CLDR quantity name.

Returns

• A map such as %{"meter" => "length", "kilogram" => "mass", ...}.

@spec base_units() :: [String.t()]

Returns the list of known base unit names from CLDR conversion data.

Returns

• A list of strings such as ["meter", "kilogram", "second", ...].

@spec categories() :: [String.t()]

Returns the list of known unit categories.

Returns

• A list of strings such as ["acceleration", "angle", "area", ...].

@spec conversion(String.t()) :: String.t() | nil

Returns the base unit for a unit, checking custom registry first.

@spec conversion_factor(String.t()) ::
  %{factor: number() | :special, offset: number()} | nil

Returns the conversion factor for a unit, checking custom registry first.

@spec conversion_factors() :: %{
  required(String.t()) => %{factor: float() | :special, offset: float()}
}

Returns the conversion factor and offset for each source unit.

The conversion from source to base unit is: base_value = value * factor + offset.

Returns

• A map such as %{"foot" => %{factor: 0.3048, offset: 0.0}, ...}.

@spec conversions() :: %{required(String.t()) => String.t()}

Returns a map from source unit name to its CLDR base unit string.

Returns

• A map such as %{"foot" => "meter", "newton" => "kilogram-meter-per-square-second", ...}.

@spec deprecated_unit_identifiers() :: [String.t()]

Returns all deprecated CLDR unit identifiers.

Returns

• A list of strings.

@spec power_components() :: [String.t()]

Returns the list of power components.

Returns

• A list of strings such as ["square", "cubic", "pow2", ...].

@spec prefix_components() :: [String.t()]

Returns the list of unit ID prefix components.

Returns

• A list of strings such as ["arc", "british", "dessert", ...].

@spec si_prefix_data() :: [
  %{
    type: String.t(),
    symbol: String.t(),
    power10: String.t(),
    power2: String.t()
  },
  ...
]

Returns detailed SI prefix data including symbols and powers.

Returns

• A list of maps with keys :type, :symbol, :power10, and :power2.

@spec si_prefix_multipliers() :: %{required(String.t()) => float()}

Returns SI prefix multipliers as a map of prefix name to numeric multiplier.

Returns

• A map such as %{"kilo" => 1000.0, "milli" => 0.001, ...}.

@spec si_prefix_names() :: [String.t()]

Returns the list of SI prefix names.

Returns

• A list of strings such as ["kilo", "milli", "mega", ...].

@spec simple_base_units() :: [String.t()]

Returns the list of fundamental (simple) base units.

These are the units with status='simple' in the CLDR unitQuantities data and form the atoms of the dimensional decomposition system.

Returns

• A list of strings such as ["candela", "kilogram", "meter", "second", ...].

@spec suffix_components() :: [String.t()]

Returns the list of unit ID suffix components.

Returns

• A list of strings such as ["force", "imperial", ...].

@spec unit_constants() :: %{required(String.t()) => float()}

Returns the resolved unit constants as a map of name to float value.

Returns

• A map such as %{"ft_to_m" => 0.3048, "lb_to_kg" => 0.45359237, ...}.

@spec unit_preferences() :: [
  %{category: String.t(), usage: String.t(), preferences: [map(), ...]},
  ...
]

Returns the CLDR unit preference data.

Each entry specifies preferred units for a category/usage/region combination.

Returns

• A list of maps with keys :category, :usage, and :preferences.

@spec valid_unit_identifiers() :: [String.t()]

Returns all valid CLDR unit identifiers with regular status.

Returns

• A list of strings such as ["length-kilometer", "mass-kilogram", ...].