# `Agentic.Cldr.Money`

A backend module for Money.

This module provides the same api as the Money
module however:

* It matches the standard behaviour of other
`ex_cldr` based libraries in maintaining the
main public API on the backend module

* It does not require the `:backend` option to
be provided since that is implied through the
use of the backend module.

All the functions in this module delegate to
the functions in `Money`.

# `abs`

```elixir
@spec abs(money :: Money.t()) :: Money.t()
```

The absolute value of a `Money` amount.
Returns a `Money` type with a positive sign for the amount.

## Arguments

* `money` is any valid `t:Money.t/0` type returned
  by `Money.new/2`

## Returns

* a `t:Money.t/0`

## Example

    iex> m = Agentic.Cldr.Money.new("USD", -100)
    iex> Agentic.Cldr.Money.abs(m)
    Money.new(:USD, "100")

# `add`

```elixir
@spec add(money_1 :: Money.t(), money_2 :: Money.t()) ::
  {:ok, Money.t()} | {:error, {module(), String.t()}}
```

Add two `Money` values.

## Arguments

* `money_1` and `money_2` are any valid `t:Money.t/0` types returned
  by `Money.new/2`

## Returns

* `{:ok, money}` or

* `{:error, reason}`

## Example

    iex> Agentic.Cldr.Money.add Money.new(:USD, 200), Money.new(:USD, 100)
    {:ok, Money.new(:USD, 300)}

    iex> Agentic.Cldr.Money.add Money.new(:USD, 200), Money.new(:AUD, 100)
    {:error, {ArgumentError, "Cannot add monies with different currencies. " <>
      "Received :USD and :AUD."}}

# `add!`

Add two `Money` values and raise on error.

## Arguments

* `money_1` and `money_2` are any valid `t:Money.t/0` types returned
  by `Money.new/2`

## Returns

* `{:ok, money}` or

* raises an exception

## Examples

    iex> Agentic.Cldr.Money.add! Money.new(:USD, 200), Money.new(:USD, 100)
    Money.new(:USD, "300")

    Agentic.Cldr.Money.add! Money.new(:USD, 200), Money.new(:CAD, 500)
    ** (ArgumentError) Cannot add two `t:Money.t/0` with different currencies. Received :USD and :CAD.

# `cmp`

```elixir
@spec cmp(money_1 :: Money.t(), money_2 :: Money.t()) ::
  -1 | 0 | 1 | {:error, {module(), String.t()}}
```

Compares two `Money` values numerically. If the first number is greater
than the second #Integer<1> is returned, if less than Integer<-1> is
returned. Otherwise, if both numbers are equal Integer<0> is returned.

## Arguments

* `money_1` and `money_2` are any valid `t:Money.t/0` types returned
  by `Money.new/2`.

## Returns

*  `-1` | `0` | `1` or

* `{:error, {module(), String.t}}`

## Examples

    iex> Agentic.Cldr.Money.cmp Money.new(:USD, 200), Money.new(:USD, 100)
    1

    iex> Agentic.Cldr.Money.cmp Money.new(:USD, 200), Money.new(:USD, 200)
    0

    iex> Agentic.Cldr.Money.cmp Money.new(:USD, 200), Money.new(:USD, 500)
    -1

    iex> Agentic.Cldr.Money.cmp Money.new(:USD, 200), Money.new(:CAD, 500)
    {:error,
     {ArgumentError,
      "Cannot compare monies with different currencies. Received :USD and :CAD."}}

# `cmp!`

Compares two `Money` values numerically and raises on error.

## Arguments

* `money_1` and `money_2` are any valid `t:Money.t/0` types returned
  by `Money.new/2`.

## Returns

*  `-1` | `0` | `1` or

* raises an exception.

## Examples

    Agentic.Cldr.Money.cmp! Money.new(:USD, 200), Money.new(:CAD, 500)
    ** (ArgumentError) Cannot compare monies with different currencies. Received :USD and :CAD.

# `compare`

```elixir
@spec compare(money_1 :: Money.t(), money_2 :: Money.t()) ::
  :gt | :eq | :lt | {:error, {module(), String.t()}}
```

Compares two `Money` values numerically. If the first number is greater
than the second :gt is returned, if less than :lt is returned, if both
numbers are equal :eq is returned.

## Arguments

* `money_1` and `money_2` are any valid `t:Money.t/0` types returned
  by `Money.new/2`.

## Returns

*  `:gt` | `:eq` | `:lt` or

* `{:error, {module(), String.t}}`.

## Examples

    iex> Agentic.Cldr.Money.compare Money.new(:USD, 200), Money.new(:USD, 100)
    :gt

    iex> Agentic.Cldr.Money.compare Money.new(:USD, 200), Money.new(:USD, 200)
    :eq

    iex> Agentic.Cldr.Money.compare Money.new(:USD, 200), Money.new(:USD, 500)
    :lt

    iex> Agentic.Cldr.Money.compare Money.new(:USD, 200), Money.new(:CAD, 500)
    {:error,
     {ArgumentError,
      "Cannot compare monies with different currencies. Received :USD and :CAD."}}

# `compare!`

Compares two `Money` values numerically and raises on error.

## Arguments

* `money_1` and `money_2` are any valid `t:Money.t/0` types returned
  by `Money.new/2`.

## Returns

*  `:gt` | `:eq` | `:lt` or

* raises an exception.

## Examples

    Agentic.Cldr.Money.compare! Money.new(:USD, 200), Money.new(:CAD, 500)
    ** (ArgumentError) Cannot compare monies with different currencies. Received :USD and :CAD.

# `cross_rate`

```elixir
@spec cross_rate(
  Money.t() | Cldr.Currency.currency_reference(),
  Cldr.Currency.currency_reference(),
  Money.ExchangeRates.t() | {:ok, Money.ExchangeRates.t()}
) :: {:ok, Decimal.t()} | {:error, {module(), String.t()}}
```

Returns the effective cross-rate to convert from one currency
to another.

## Arguments

* `from` is any `t:Money.t/0` struct returned by `Cldr.Currency.new/2` or a valid
   currency code

* `to_currency` is a valid currency code into which the `money` is converted

* `rates` is a `Map` of currency rates where the map key is an upcased
  atom or string and the value is a Decimal conversion factor.  The default is the
  latest available exchange rates returned from `Money.ExchangeRates.latest_rates()`

## Examples

    Agentic.Cldr.Money.cross_rate(Money.new(:USD, 100), :AUD, %{USD: Decimal.new(1), AUD: Decimal.new("0.7345")})
    {:ok, Decimal.new("0.7345")}

    Agentic.Cldr.Money.cross_rate Money.new(:USD, 100), :ZZZ, %{USD: Decimal.new(1), AUD: Decimal.new(0.7345)}
    ** (Cldr.UnknownCurrencyError) Currency :ZZZ is not known

# `cross_rate!`

```elixir
@spec cross_rate!(
  Money.t() | Cldr.Currency.currency_reference(),
  Cldr.Currency.currency_reference(),
  Money.ExchangeRates.t() | {:ok, Money.ExchangeRates.t()}
) :: Decimal.t() | no_return()
```

Returns the effective cross-rate to convert from one currency
to another.

## Arguments

* `from` is any `t:Money.t/0` struct returned by `Cldr.Currency.new/2` or a valid
   currency code

* `to_currency` is a valid currency code into which the `money` is converted

* `rates` is a `Map` of currency rates where the map key is an upcased
  atom or string and the value is a Decimal conversion factor.  The default is the
  latest available exchange rates returned from `Money.ExchangeRates.latest_rates()`

## Examples

    iex> Agentic.Cldr.Money.cross_rate!(Money.new(:USD, 100), :AUD, %{USD: Decimal.new(1), AUD: Decimal.new("0.7345")})
    Decimal.new("0.7345")

    iex> Agentic.Cldr.Money.cross_rate!(:USD, :AUD, %{USD: Decimal.new(1), AUD: Decimal.new("0.7345")})
    Decimal.new("0.7345")

    Agentic.Cldr.Money.cross_rate Money.new(:USD, 100), :ZZZ, %{USD: Decimal.new(1), AUD: Decimal.new("0.7345")}
    ** (Cldr.UnknownCurrencyError) Currency :ZZZ is not known

# `div`

```elixir
@spec div(Money.t(), Cldr.Math.number_or_decimal()) ::
  {:ok, Money.t()} | {:error, {module(), String.t()}}
```

Divide a `Money` value by a number.

## Arguments

* `money` is any valid `t:Money.t/0` types returned.
  by `Money.new/2`

* `number` is an integer, float or `t:Decimal.t/0`.

> Note that dividing one `t:Money.t/0` by another is not supported.

## Returns

* `{:ok, money}` or

* `{:error, reason}`

## Example

    iex> Agentic.Cldr.Money.div Money.new(:USD, 200), 2
    {:ok, Money.new(:USD, 100)}

    iex> Agentic.Cldr.Money.div(Money.new(:USD, 200), "xx")
    {:error, {ArgumentError, "Cannot divide money by \"xx\""}}

# `div!`

Divide a `Money` value by a number and raise on error.

## Arguments

* `money` is any valid `t:Money.t/0` types returned
  by `Money.new/2`

* `number` is an integer, float or `t:Decimal.t/0`

## Returns

* a `t:Money.t/0` struct or

* raises an exception

## Examples

    iex> Agentic.Cldr.Money.div Money.new(:USD, 200), 2
    {:ok, Money.new(:USD, 100)}

    Agentic.Cldr.Money.div(Money.new(:USD, 200), "xx")
    ** (ArgumentError) "Cannot divide money by \"xx\""]}}

# `equal?`

```elixir
@spec equal?(money_1 :: Money.t(), money_2 :: Money.t()) :: boolean()
```

Returns a boolean indicating if two `Money` values are equal

## Arguments

* `money_1` and `money_2` are any valid `t:Money.t/0` types returned
  by `Money.new/2`

## Returns

* `true` or `false`

## Example

    iex> Agentic.Cldr.Money.equal? Money.new(:USD, 200), Money.new(:USD, 200)
    true

    iex> Agentic.Cldr.Money.equal? Money.new(:USD, 200), Money.new(:USD, 100)
    false

# `from_float`
*since 2.0.0* 

```elixir
@spec from_float(
  float() | Cldr.Currency.currency_reference(),
  float() | Cldr.Currency.currency_reference(),
  Keyword.t()
) :: Money.t() | {:error, {module(), String.t()}}
```

Returns a `t:Money.t/0` struct from a currency code and a float amount, or
an error tuple of the form `{:error, {exception, message}}`.

Floats are fraught with danger in computer arithmetic due to the
unexpected loss of precision during rounding. The IEEE754 standard
indicates that a number with a precision of 16 digits should
round-trip convert without loss of fidelity. This function supports
numbers with a precision up to 15 digits and will error if the
provided amount is outside that range.

**Note** that `Money` cannot detect lack of precision or rounding errors
introduced upstream. This function therefore should be used with
great care and its use should be considered potentially harmful.

## Arguments

* `currency_code` is an [ISO4217](https://en.wikipedia.org/wiki/ISO_4217)
  binary or atom currency code or an
  [ISO 24165](https://www.iso.org/standard/80601.html) token identifier or shortname.

* `amount` is a float

## Examples

    iex> Agentic.Cldr.Money.from_float 1.23456, :USD
    Money.new(:USD, "1.23456")

    iex> Agentic.Cldr.Money.from_float 1.234567890987656, :USD
    {:error,
      {Money.InvalidAmountError,
        "The precision of the float 1.234567890987656 is " <>
        "greater than 15 which could lead to unexpected results. " <>
        "Reduce the precision or call Money.new/2 with a Decimal or String amount"}}

# `from_float!`

```elixir
@spec from_float!(
  float() | Cldr.Currency.currency_reference(),
  float() | Cldr.Currency.currency_reference(),
  Keyword.t()
) :: Money.t() | no_return()
```

Returns a `t:Money.t/0` struct from a currency code and a float amount, or
raises an exception if the currency code is invalid.

See `Money.from_float/2` for further information.

**Note** that `Money` cannot detect lack of precision or rounding errors
introduced upstream. This function therefore should be used with
great care and its use should be considered potentially harmful.

## Arguments

* `currency_code` is an ISO4217 three-character upcased binary or atom

* `amount` is a float

* `options` is a keyword list of options passed
  to `Money.new/3`. The default is `[]`.

## Examples

    iex> Agentic.Cldr.Money.from_float!(:USD, 1.234)
    Money.new(:USD, "1.234")

    Money.from_float!(:USD, 1.234567890987654)
    #=> ** (Money.InvalidAmountError) The precision of the float 1.234567890987654 is greater than 15 which could lead to unexpected results. Reduce the precision or call Money.new/2 with a Decimal or String amount
        (ex_money) lib/money.ex:293: Money.from_float!/2

# `from_integer`

```elixir
@spec from_integer(integer(), Cldr.Currency.currency_reference(), Keyword.t()) ::
  Money.t() | {:error, {module(), String.t()}}
```

Convert an integer representation of money into a `Money` struct.

This is the inverse operation of `Money.to_integer_exp/1`. Note
that the ISO definition of currency digits (subunit) is *always*
used.  This is, in some cases like the Colombian Peso (COP)
different to the CLDR definition.

## Options

* `integer` is an integer representation of a mooney item including
  any decimal digits.  ie. 20000 would interpreted to mean $200.00

* `currency` is the currency code for the `integer`.  The assumed
  decimal places is derived from the currency code.

## Returns

* A `Money` struct or

* `{:error, {Cldr.UnknownCurrencyError, message}}`

## Examples

    iex> Agentic.Cldr.Money.from_integer(20000, :USD)
    Money.new(:USD, "200.00")

    iex> Agentic.Cldr.Money.from_integer(200, :JPY)
    Money.new(:JPY, "200")

    iex> Agentic.Cldr.Money.from_integer(20012, :USD)
    Money.new(:USD, "200.12")

    iex> Agentic.Cldr.Money.from_integer(20012, :COP)
    Money.new(:COP, "200.12")

# `known_currencies`

# `known_current_currencies`

# `known_historic_currencies`

# `known_tender_currencies`

# `mult`

```elixir
@spec mult(Money.t(), Cldr.Math.number_or_decimal()) ::
  {:ok, Money.t()} | {:error, {module(), String.t()}}
```

Multiply a `Money` value by a number.

## Arguments

* `money` is any valid `t:Money.t/0` type returned
  by `Money.new/2`.

* `number` is an integer, float or `t:Decimal.t/0`.

> Note that multipling one `t:Money.t/0` by another is not supported.

## Returns

* `{:ok, money}` or

* `{:error, reason}`

## Example

    iex> Agentic.Cldr.Money.mult(Money.new(:USD, 200), 2)
    {:ok, Money.new(:USD, 400)}

    iex> Agentic.Cldr.Money.mult(Money.new(:USD, 200), "xx")
    {:error, {ArgumentError, "Cannot multiply money by \"xx\""}}

# `mult!`

```elixir
@spec mult!(Money.t(), Cldr.Math.number_or_decimal()) :: Money.t() | none()
```

Multiply a `Money` value by a number and raise on error.

## Arguments

* `money` is any valid `t:Money.t/0` types returned
  by `Money.new/2`.

* `number` is an integer, float or `Decimal.t`

## Returns

* a `t:Money.t/0` or

* raises an exception

## Examples

    iex> Agentic.Cldr.Money.mult!(Money.new(:USD, 200), 2)
    Money.new(:USD, "400")

    Agentic.Cldr.Money.mult!(Money.new(:USD, 200), :invalid)
    ** (ArgumentError) Cannot multiply money by :invalid

# `new`

```elixir
@spec new(
  Money.amount() | Cldr.Currency.currency_reference(),
  Money.amount() | Cldr.Currency.currency_reference(),
  Keyword.t()
) :: Money.t() | {:error, {module(), String.t()}}
```

Returns a `t:Money.t/0` struct from a currency code and a currency amount or
an error tuple of the form `{:error, {exception, message}}`.

## Arguments

* `currency_code` is an [ISO4217](https://en.wikipedia.org/wiki/ISO_4217)
  binary or atom currency code or an
  [ISO 24165](https://www.iso.org/standard/80601.html) token identifier or shortname.

* `amount` is an integer, string or Decimal

## Options

`:locale` is any known locale.  The locale is used to normalize any
binary (String) amounts to a form that can be consumed by `Decimal.new/1`.
This consists of removing any localised grouping characters and replacing
the localised decimal separator with a ".".

Note that the `currency_code` and `amount` arguments can be supplied in
either order,

## Examples

    iex> Agentic.Cldr.Money.new(:USD, 100)
    Money.new(:USD, "100")

    iex> Agentic.Cldr.Money.new(100, :USD)
    Money.new(:USD, "100")

    iex> Agentic.Cldr.Money.new("USD", 100)
    Money.new(:USD, "100")

    iex> Agentic.Cldr.Money.new("thb", 500)
    Money.new(:THB, "500")

    iex> Agentic.Cldr.Money.new("EUR", Decimal.new(100))
    Money.new(:EUR, "100")

    iex> Agentic.Cldr.Money.new(:EUR, "100.30")
    Money.new(:EUR, "100.30")

    iex> Agentic.Cldr.Money.new(:XYZZ, 100)
    {:error, {Money.UnknownCurrencyError, "The currency :XYZZ is unknown"}}

    iex> Agentic.Cldr.Money.new("1.000,99", :EUR, locale: "de")
    Money.new(:EUR, "1000.99")

    iex> Agentic.Cldr.Money.new 123.445, :USD
    {:error,
     {Money.InvalidAmountError,
      "Float amounts are not supported in new/2 due to potenial " <>
      "rounding and precision issues.  If absolutely required, " <>
      "use Money.from_float/2"}}

# `new!`

```elixir
@spec new!(
  Money.amount() | Cldr.Currency.currency_reference(),
  Money.amount() | Cldr.Currency.currency_reference(),
  Keyword.t()
) :: Money.t() | no_return()
```

Returns a `t:Money.t/0` struct from a currency code and a currency amount. Raises an
exception if the current code is invalid.

## Arguments

* `currency_code` is an ISO4217 three-character upcased binary or atom

* `amount` is an integer, float or Decimal

## Examples

    Money.new!(:XYZZ, 100)
    ** (Money.UnknownCurrencyError) Currency :XYZZ is not known
      (ex_money) lib/money.ex:177: Money.new!/2

# `normalize`
*since 5.0.0* 

```elixir
@spec normalize(Money.t()) :: Money.t()
```

Normalizes the underlying `Decimal` amount on the
given `t:Money.t/0`.

This will normalize the coefficient and exponent of the
decimal amount in a standard way that may aid in
native comparison of `t:Money.t/0` items.

## Example

    iex> x = %Money{currency: :USD, amount: %Decimal{sign: 1, coef: 42, exp: 0}}
    Money.new(:USD, "42")
    iex> y = %Money{currency: :USD, amount: %Decimal{sign: 1, coef: 4200000000, exp: -8}}
    Money.new(:USD, "42.00000000")
    iex> x == y
    false
    iex> y = Money.normalize(x)
    Money.new(:USD, "42")
    iex> x == y
    true

# `parse`
*since 3.2.0* 

```elixir
@spec parse(String.t(), Keyword.t()) :: Money.t() | {:error, {module(), String.t()}}
```

Parse a string and return a `t:Money.t/0` or an error.

The string to be parsed is required to have a currency
code and an amount.  The currency code may be placed
before the amount or after, but not both.

Parsing is strict.  Additional text surrounding the
currency code and amount will cause the parse to
fail.

## Arguments

* `string` is a string to be parsed

* `options` is a keyword list of options that is
  passed to `Money.new/3` with the exception of
  the options listed below

## Options

* `backend` is any module() that includes `use Cldr` and therefore
  is a `Cldr` backend module(). The default is `Money.default_backend!/0`

* `locale_name` is any valid locale name returned by `Cldr.known_locale_names/1`
  or a `Cldr.LanguageTag` struct returned by `Cldr.Locale.new!/2`
  The default is `<backend>.get_locale()`

* `currency_filter` is an `atom` or list of `atoms` representing the
  currency types to be considered for a match. If a list of
  atoms is given, the currency must meet all criteria for
  it to be considered.

  * `:all`, the default, considers all currencies

  * `:current` considers those currencies that have a `:to`
    date of nil and which also is a known ISO4217 currency

  * `:historic` is the opposite of `:current`

  * `:tender` considers currencies that are legal tender

  * `:unannotated` considers currencies that don't have
    "(some string)" in their names.  These are usually
    financial instruments.

* `fuzzy` is a float greater than `0.0` and less than or
  equal to `1.0` which is used as input to the
  `String.jaro_distance/2` to determine is the provided
  currency string is *close enough* to a known currency
  string for it to identify definitively a currency code.
  It is recommended to use numbers greater than `0.8` in
  order to reduce false positives.

* `:default_currency` is any valid currency code or `false`
  that will used if no currency code, symbol or description is
  indentified in the parsed string. The default is `nil`
  which means that the default currency associated with
  the `:locale` option will be used. If `false` then the
  currency assocated with the `:locale` option will not be
  used and an error will be returned if there is no currency
  in the string being parsed.

## Returns

* a `t:Money.t/0` if parsing is successful or

* `{:error, {exception, reason}}` if an error is
  detected.

## Examples

    iex> Agentic.Cldr.Money.parse("USD 100")
    Money.new(:USD, "100")

    iex> Agentic.Cldr.Money.parse "USD 100,00", locale: "de"
    Money.new(:USD, "100.00")

    iex> Agentic.Cldr.Money.parse("100 USD")
    Money.new(:USD, "100")

    iex> Agentic.Cldr.Money.parse("100 eurosports", fuzzy: 0.8)
    Money.new(:EUR, "100")

    iex> Agentic.Cldr.Money.parse("100 eurosports", fuzzy: 0.9)
    {:error,
      {Money.UnknownCurrencyError, "The currency \"eurosports\" is unknown or not supported"}}

    iex> Agentic.Cldr.Money.parse("100 afghan afghanis")
    Money.new(:AFN, "100")

    iex> Agentic.Cldr.Money.parse("100", default_currency: false)
    {:error,
      {Money.Invalid, "A currency code, symbol or description must be specified but was not found in \"100\""}}

    iex> Agentic.Cldr.Money.parse("USD 100 with trailing text")
    {:error,
      {Money.ParseError, "Could not parse \"USD 100 with trailing text\"."}}

# `put_fraction`

Set the fractional part of a `Money`.

## Arguments

* `money` is a ``t:Money.t/0`` struct

* `fraction` is an integer amount that will be set
  as the fraction of the `money`

## Notes

The fraction can only be set if it matches the number of
decimal digits for the currency associated with the `money`.
Therefore, for a currency with 2 decimal digits, the
maximum for `fraction` is `99`.

## Examples

    iex> Agentic.Cldr.Money.put_fraction Money.new(:USD, "2.49"), 99
    Money.new(:USD, "2.99")

    iex> Agentic.Cldr.Money.put_fraction Money.new(:USD, "2.49"), 0
    Money.new(:USD, "2.0")

    iex> Agentic.Cldr.Money.put_fraction Money.new(:USD, "2.49"), 999
    {:error,
     {Money.InvalidAmountError, "Rounding up to 999 is invalid for currency :USD"}}

# `reduce`

> This function is deprecated. Use Agentic.Cldr.Money.normalize/1 instead..

# `round`

```elixir
@spec round(Money.t(), Keyword.t()) :: Money.t() | {:error, {module(), binary()}}
```

Round a `Money` value into the acceptable range for the requested currency.

## Arguments

* `money` is a `t:Money.t/0` struct.

* `options` is a keyword list of options.

## Options

  * `:rounding_mode` that defines how the number will be rounded.  See
    `Decimal.Context`.  The default is `:half_even` which is also known
    as "banker's rounding".

  * `:currency_digits` which determines the rounding increment.
    The valid options are `:cash`, `:accounting` and `:iso` or
    an integer value representing the rounding factor.  The
    default is `:iso`.

## Notes

There are two kinds of rounding applied:

1. Round to the appropriate number of fractional digits.

3. Apply an appropriate rounding increment.  Most currencies
   round to the same precision as the number of decimal digits, but some
   such as `:CHF` round to a minimum such as `0.05` when its a cash
   amount. The rounding increment is applied when the option
   `:currency_digits` is set to `:cash`.

## Examples

    iex> Agentic.Cldr.Money.round Money.new("123.73", :CHF), currency_digits: :cash
    Money.new(:CHF, "123.75")

    iex> Agentic.Cldr.Money.round Money.new("123.73", :CHF), currency_digits: 0
    Money.new(:CHF, "124")

    iex> Agentic.Cldr.Money.round Money.new("123.7456", :CHF)
    Money.new(:CHF, "123.75")

    iex> Agentic.Cldr.Money.round Money.new("123.7456", :JPY)
    Money.new(:JPY, "124")

# `split`

```elixir
@spec split(Money.t(), non_neg_integer()) :: {Money.t(), Money.t()}
```

Split a `Money` value into a number of parts maintaining the currency's
precision and rounding and ensuring that the parts sum to the original
amount.

## Arguments

* `money` is any `t:Money.t/0` struct

* `parts` is an integer number of parts into which the `money` is split

Returns a tuple `{dividend, remainder}` as the function result
derived as follows:

1. Round the money amount to the required currency precision using
`Money.round/1`.

2. Divide the result of step 1 by the integer divisor.

3. Round the result of the division to the precision of the currency
using `Money.round/1`.

4. Return two numbers: the result of the division and any remainder
that could not be applied given the precision of the currency.

## Examples

    Agentic.Cldr.Money.split Money.new(123.5, :JPY), 3
    {¥41, ¥1}

    Agentic.Cldr.Money.split Money.new(123.4, :JPY), 3
    {¥41, ¥0}

    Agentic.Cldr.Money.split Money.new(123.7, :USD), 9
    {$13.74, $0.04}

# `sub`

```elixir
@spec sub(money_1 :: Money.t(), money_2 :: Money.t()) ::
  {:ok, Money.t()} | {:error, {module(), String.t()}}
```

Subtract one `Money` value struct from another.

## Options

* `money_1` and `money_2` are any valid `t:Money.t/0` types returned
  by `Money.new/2`.

## Returns

* `{:ok, money}` or

* `{:error, reason}`.

## Example

    iex> Agentic.Cldr.Money.sub Money.new(:USD, 200), Money.new(:USD, 100)
    {:ok, Money.new(:USD, 100)}

# `sub!`

```elixir
@spec sub!(money_1 :: Money.t(), money_2 :: Money.t()) :: Money.t() | none()
```

Subtract one `Money` value struct from another and raise on error.

Returns either `{:ok, money}` or `{:error, reason}`.

## Arguments

* `money_1` and `money_2` are any valid `t:Money.t/0` types returned
  by `Money.new/2`.

## Returns

* a `t:Money.t/0` struct or

* raises an exception

## Examples

    iex> Agentic.Cldr.Money.sub! Money.new(:USD, 200), Money.new(:USD, 100)
    Money.new(:USD, "100")

    Agentic.Cldr.Money.sub! Money.new(:USD, 200), Money.new(:CAD, 500)
    ** (ArgumentError) Cannot subtract monies with different currencies. Received :USD and :CAD.

# `to_currency`

```elixir
@spec to_currency(
  Money.t(),
  Cldr.Currency.currency_reference(),
  Money.ExchangeRates.t()
  | {:ok, Money.ExchangeRates.t()}
  | {:error, {module(), String.t()}}
) :: {:ok, Money.t()} | {:error, {module(), String.t()}}
```

Convert `money` from one currency to another.

## Arguments

* `money` is any `t:Money.t/0` struct returned by `Cldr.Currency.new/2`

* `to_currency` is a valid currency code into which the `money` is converted

* `rates` is a `Map` of currency rates where the map key is an upcased
  atom or string and the value is a Decimal conversion factor.  The default is the
  latest available exchange rates returned from `Money.ExchangeRates.latest_rates()`

## Examples

    Agentic.Cldr.Money.to_currency(Money.new(:USD, 100), :AUD, %{USD: Decimal.new(1), AUD: Decimal.from_float(0.7345)})
    {:ok, Money.new(:AUD, "73.4500")}

    Agentic.Cldr.Money.to_currency(Money.new("USD", 100), "AUD", %{"USD" => Decimal.new(1), "AUD" => Decimal.from_float(0.7345)})
    {:ok, Money.new(:AUD, "73.4500")}

    iex> Agentic.Cldr.Money.to_currency Money.new(:USD, 100), :AUDD, %{USD: Decimal.new(1), AUD: Decimal.from_float(0.7345)}
    {:error, {Cldr.UnknownCurrencyError, "The currency :AUDD is unknown"}}

    iex> Agentic.Cldr.Money.to_currency Money.new(:USD, 100), :CHF, %{USD: Decimal.new(1), AUD: Decimal.from_float(0.7345)}
    {:error, {Money.ExchangeRateError, "No exchange rate is available for currency :CHF"}}

# `to_currency!`

```elixir
@spec to_currency!(
  Money.t(),
  Cldr.Currency.currency_reference(),
  Money.ExchangeRates.t()
  | {:ok, Money.ExchangeRates.t()}
  | {:error, {module(), String.t()}}
) :: Money.t() | no_return()
```

Convert `money` from one currency to another and raises on error

## Arguments

* `money` is any `t:Money.t/0` struct returned by `Cldr.Currency.new/2`

* `to_currency` is a valid currency code into which the `money` is converted

* `rates` is a `Map` of currency rates where the map key is an upcased
  atom or string and the value is a Decimal conversion factor.  The default is the
  latest available exchange rates returned from `Money.ExchangeRates.latest_rates()`

## Examples

    iex> Agentic.Cldr.Money.to_currency! Money.new(:USD, 100), :AUD, %{USD: Decimal.new(1), AUD: Decimal.from_float(0.7345)}
    Money.new(:AUD, "73.4500")

    iex> Agentic.Cldr.Money.to_currency! Money.new("USD", 100), "AUD", %{"USD" => Decimal.new(1), "AUD" => Decimal.from_float(0.7345)}
    Money.new(:AUD, "73.4500")

    Agentic.Cldr.Money.to_currency! Money.new(:USD, 100), :ZZZ, %{USD: Decimal.new(1), AUD: Decimal.from_float(0.7345)}
    ** (Cldr.UnknownCurrencyError) Currency :ZZZ is not known

# `to_decimal`

```elixir
@spec to_decimal(money :: Money.t()) :: Decimal.t()
```

Returns the amount part of a `Money` type as a `Decimal`

## Arguments

* `money` is any valid `t:Money.t/0` type returned
  by `Money.new/2`

## Returns

* a `Decimal.t`

## Example

    iex> m = Agentic.Cldr.Money.new("USD", 100)
    iex> Agentic.Cldr.Money.to_decimal(m)
    Decimal.new("100")

# `to_integer_exp`

Returns a tuple comprising the currency code, integer amount,
exponent and remainder

Some services require submission of money items as an integer
with an implied exponent that is appropriate to the currency.

Rather than return only the integer, `Money.to_integer_exp`
returns the currency code, integer, exponent and remainder.
The remainder is included because to return an integer
money with an implied exponent the `Money` has to be rounded
potentially leaving a remainder.

## Arguments

* `money` is any `t:Money.t/0` struct returned by `Cldr.Currency.new/2`

## Notes

* Since the returned integer is expected to have the implied fractional
digits the `Money` needs to be rounded which is what this function does.

## Example

    iex> m = Agentic.Cldr.Money.new(:USD, "200.012356")
    Money.new(:USD, "200.012356")
    iex> Agentic.Cldr.Money.to_integer_exp(m)
    {:USD, 20001, -2, Money.new(:USD, "0.002356")}

    iex> m = Agentic.Cldr.Money.new(:USD, "200.00")
    Money.new(:USD, "200.00")
    iex> Agentic.Cldr.Money.to_integer_exp(m)
    {:USD, 20000, -2, Money.new(:USD, "0.00")}

# `to_string`

```elixir
@spec to_string(Money.t(), Keyword.t() | Cldr.Number.Format.Options.t()) ::
  {:ok, String.t()} | {:error, {atom(), String.t()}}
```

Returns a formatted string representation of a `Money{}`.

Formatting is performed according to the rules defined by CLDR. See
`Cldr.Number.to_string/2` for formatting options.  The default is to format
as a currency which applies the appropriate rounding and fractional digits
for the currency.

## Arguments

* `money` is any valid `t:Money.t/0` type returned
  by `Money.new/2`

* `options` is a keyword list of options

## Returns

* `{:ok, string}` or

* `{:error, reason}`

## Options

* `:backend` is any CLDR backend module.  The default is
  `Money.default_backend!/0`.

* Any other options are passed to `Cldr.Number.to_string/3`

## Examples

    iex> Agentic.Cldr.Money.to_string Money.new(:USD, 1234)
    {:ok, "$1,234.00"}

    iex> Agentic.Cldr.Money.to_string Money.new(:JPY, 1234)
    {:ok, "¥1,234"}

    iex> Agentic.Cldr.Money.to_string Money.new(:THB, 1234)
    {:ok, "THB 1,234.00"}

    iex> Agentic.Cldr.Money.to_string Money.new(:USD, 1234), format: :long
    {:ok, "1,234 US dollars"}

# `to_string!`

```elixir
@spec to_string!(Money.t(), Keyword.t()) :: String.t() | no_return()
```

Returns a formatted string representation of a `t:Money.t/0` or raises if
there is an error.

Formatting is performed according to the rules defined by CLDR. See
`Cldr.Number.to_string!/2` for formatting options.  The default is to format
as a currency which applies the appropriate rounding and fractional digits
for the currency.

## Arguments

* `money` is any valid `t:Money.t/0` type returned
  by `Money.new/2`

* `options` is a keyword list of options

## Options

* `:backend` is any CLDR backend module.  The default is
  `Money.default_backend!/0`.

* Any other options are passed to `Cldr.Number.to_string/3`

## Examples

    iex> Agentic.Cldr.Money.to_string! Money.new(:USD, 1234)
    "$1,234.00"

    iex> Agentic.Cldr.Money.to_string! Money.new(:JPY, 1234)
    "¥1,234"

    iex> Agentic.Cldr.Money.to_string! Money.new(:THB, 1234)
    "THB 1,234.00"

    iex> Agentic.Cldr.Money.to_string! Money.new(:USD, 1234), format: :long
    "1,234 US dollars"

# `validate_currency`

# `zero`

```elixir
@spec zero(Cldr.Currency.currency_reference() | Money.t(), Keyword.t()) ::
  Money.t() | {:error, {module(), binary()}}
```

Return a zero amount `t:Money` in the given currency.

## Arguments

* `money_or_currency` is either a `t:Money` or
  a currency code

* `options` is a keyword list of options passed
  to `Money.new/3`. The default is `[]`.

## Example

    iex> Agentic.Cldr.Money.zero(:USD)
    Money.new(:USD, "0")

    iex> money = Money.new(:USD, 200)
    iex> Agentic.Cldr.Money.zero(money)
    Money.new(:USD, "0")

    iex> Agentic.Cldr.Money.zero :ZZZ
    {:error, {Cldr.UnknownCurrencyError, "The currency :ZZZ is unknown"}}

---

*Consult [api-reference.md](api-reference.md) for complete listing*