Monetized

As a general rule, using floats to store money is a bad idea.

Integers on the other hand are great.

However, in order for it to be an actual viable option we must first lay some groundwork and this is why Monetized library exists.

Usage

alias Monetized.Money
alias Monetized.Math

# Create with a string
item_one = Money.make("£ 200.50")
item_one == %Monetized.Money{currency: "GBP", units: 20050}

# Or a float
item_two = Money.make(10.25, [currency: "GBP"])
item_two == %Monetized.Money{currency: "GBP", units: 1025}

# Adding two moneys together
Math.add(item_one, item_two) == %Monetized.Money{currency: "GBP", units: 21075}

# Or an integer
balance = Money.make(100_000_00, [units: true])

# Substracting from money
result = Math.sub(balance, 50_000)
result == %Monetized.Money{currency: "USD", units: 5000000}

# Getting the string representation
Money.to_string(result, [show_currency: true]) == "$ 50,000.00"

# You can also use `from_integer/2`, `from_float/2` and `from_string/2`
# respectively if the desired behavior is to raise when the amount is 
# not of the expected type.

# If either the symbol or the currency key is found within the string,
# that currency will be used. However, if a different currency is given in the
# options, it will take precedence.
Money.from_string("£ 200") == %Monetized.Money{currency: "GBP", units: 20000}
Money.from_string("200 EUR") == %Monetized.Money{currency: "EUR", units: 20000}

# Passing `units: true` in the options will make it assume the amount is
# already in the basic fractional unit format
Money.from_integer(20050, [units: true]) == %Monetized.Money{currency: "USD", units: 20050}

Money.from_float(200.50) == %Monetized.Money{currency: "USD", units: 20050}

Money.from_integer("10") # This will raise FunctionClauseError

Check the docs for more examples

Note

Although you can give Money.make/2 a float to create a money struct, serves only as a convenience utility and none of the internal operactions are done on floats but rather on the basic fractional units (integers).

Config

config :monetized, config: [
  delimiter: ",",
  separator: ".",
  currency: "USD",
  format: "%c %n%s%d"
]

Installation

Add monetized to your list of dependencies in mix.exs:

def deps do
  [{:monetized, "~> 0.2.0"}]
end

Contributing

See CONTRIBUTING.md for details.

Licensing

See LICENSE.md