Add Cldr.Currency.current_territory_currencies/1

CHANGELOG.md

@@ -1,5 +1,13 @@
 # Changelog
 
+## Cldr_Currencies v2.15.0
+
+This is the changelog for Cldr_Currencies v2.15.0 released on January 28th, 2023.  For older changelogs please consult the release tag on [GitHub](https://github.com/elixir-cldr/cldr_currencies/tags)
+
+### Enhancements
+
+* Add `Cldr.Currency.current_territory_currencies/1` and `MyApp.Cldr.Currency.current_territory_currencies/0` that returns a mapping from territory code from currency type for all territories that have a current currency.  Thanks for @lawik for the inspiration.
+
 ## Cldr_Currencies v2.14.3
 
 This is the changelog for Cldr_Currencies v2.14.3 released on January 27th, 2023.  For older changelogs please consult the release tag on [GitHub](https://github.com/elixir-cldr/cldr_currencies/tags)

lib/cldr/backend.ex

@@ -591,6 +591,30 @@ defmodule Cldr.Currency.Backend do
           {:error, Cldr.Locale.locale_error(locale)}
         end
 
+        @doc """
+        Returns a mapping from a territory code to its
+        current currency code.
+
+        If a territory has no current currency (like
+        Antartica, territory code `:AQ`) then no
+        mapping is returned for that territory.
+
+        ## Returns
+
+        * A map of `{territory_code => Cldr.Currency.t}`
+
+        ## Example
+
+            iex> #{inspect __MODULE__}.current_territory_currencies()
+
+        """
+        @doc since: "2.15.0"
+
+        @spec current_territory_currencies() :: %{Cldr.Locale.territory_code() => Cldr.Currency.t()}
+        def current_territory_currencies do
+          Cldr.Currency.current_territory_currencies(unquote(backend))
+        end
+
         @doc """
         Returns a map of the metadata for all currencies for
         a given locale and raises on error.

lib/cldr/currency.ex

@@ -757,6 +757,47 @@ defmodule Cldr.Currency do
     end
   end
 
+  @doc """
+  Returns a mapping from a territory code to its
+  current currency code.
+
+  If a territory has no current currency (like
+  Antartica, territory code `:AQ`) then no
+  mapping is returned for that territory.
+
+  ## Arguments
+
+  * `backend` is any module that includes `use Cldr` and therefore
+    is a `Cldr` backend module. The default is `Cldr.default_backend!/0`
+
+  ## Returns
+
+  * A map of `{territory_code => Cldr.Currency.t}`
+
+  """
+  @doc since: "2.15.0"
+
+  @spec current_territory_currencies() :: %{Cldr.Locale.territory_code() => t()}
+  def current_territory_currencies(backend \\ Cldr.default_backend!()) do
+    territory_currencies()
+    |> Enum.map(fn
+      {:ZZ, _currencies} ->
+        nil
+
+      {territory, _currencies} ->
+        case current_currency_for_territory(territory) do
+          nil -> {territory, nil}
+          currency -> {territory, currency_for_code!(currency, backend)}
+        end
+    end)
+    |> Enum.reject(fn
+      {_territory, nil} -> true
+      nil -> true
+      _other -> false
+    end)
+    |> Map.new()
+  end
+
   @doc """
   Returns a list of historic and the current
   currency for a given locale.
@@ -882,9 +923,10 @@ defmodule Cldr.Currency do
       of an ISO 4217 currency code, or a `t:Cldr.Currency` struct.
 
   * `backend` is any module that includes `use Cldr` and therefore
-    is a `Cldr` backend module
+    is a `Cldr` backend module. The default is `Cldr.default_backend!/0`.
 
-  * `options` is a `Keyword` list of options.
+  * `options` is a `Keyword` list of options. The default is
+    `[]`.
 
   ## Options
 
@@ -936,13 +978,13 @@ defmodule Cldr.Currency do
   @spec currency_for_code(code() | t(), Cldr.backend(), Keyword.t()) ::
           {:ok, t()} | {:error, {module(), String.t()}}
 
-  def currency_for_code(currency_or_currency_code, backend, options \\ [])
+  def currency_for_code(currency_or_currency_code, backend \\ Cldr.default_backend!(), options \\ [])
 
   def currency_for_code(%__MODULE__{} = currency, _backend, _options) do
     {:ok, currency}
   end
 
-  def currency_for_code(currency_code, backend, options) do
+  def currency_for_code(currency_code, backend, options) when is_atom(backend) and is_list(options) do
     {locale, backend} = Cldr.locale_and_backend_from(options[:locale], backend)
 
     with {:ok, code} <- Cldr.validate_currency(currency_code),
@@ -952,6 +994,10 @@ defmodule Cldr.Currency do
     end
   end
 
+  def currency_for_code(currency_code, nil, [] = options) when is_list(options) do
+    currency_for_code(currency_code, nil, options)
+  end
+
   @doc """
   Returns the currency metadata for the requested currency code.
 
@@ -1014,7 +1060,7 @@ defmodule Cldr.Currency do
   @spec currency_for_code!(code() | t(), Cldr.backend(), Keyword.t()) ::
           t() | no_return()
 
-  def currency_for_code!(currency_or_currency_code, backend, options \\ []) do
+  def currency_for_code!(currency_or_currency_code, backend \\ nil, options \\ []) do
     case currency_for_code(currency_or_currency_code, backend, options) do
       {:ok, currency} -> currency
       {:error, {exception, reason}} -> raise exception, reason

mix.exs

@@ -1,7 +1,7 @@
 defmodule Cldr.Currencies.MixProject do
   use Mix.Project
 
-  @version "2.14.3"
+  @version "2.15.0"
 
   def project do
     [