cashrb

cashrb

Lightweight money and currency handler for working with financial calculations. Ensures precision without sacrificing speed. Eschews complexity by only providing what you need to get your job done.

Usage

require 'cashrb'

# Works with cents to avoid Floating point errors
n = Cash.new(100)
n.cents #=> 100
n.to_s  #=> "1.00"
n.to_f  #=> 1.0

# Don't like passing cents, set :from => :decimal and use a decimal value
n = Cash.new(1.11, from: :decimal)
n.cents #=> 111
n.to_s  #=> "1.11"
n.to_f  #=> 1.11

# Hate cents and always want to pass a decimal, just set the default
Cash.default_from = :decimal
n = Cash.new(1.11)
n.cents #=> 111

# Define currency as you see fit.
a = Cash.new(100, currency: :usd)
b = Cash.new(100, currency: :eur)
a + b #=> Error! Cash::IncompatibleCurrency

# Default is 100 cents in a dollar. Is your currency different, then just
# tell it.
n = Cash.new(100, cents_in_dollar: 5)
n.cents #=> 100
n.to_s  #=> "20.0"
n.to_f  #=> 20.0

n = Cash.new(100, cents_in_dollar: 10)
n.cents #=> 100
n.to_s  #=> "10.0"
n.to_f  #=> 10.0

n = Cash.new(100, cents_in_dollar: 1)
n.cents #=> 100
n.to_s  #=> "100"
n.to_f  #=> 100.0

# The default rounding method when dealing with fractional cents is
# BigDecimal::ROUND_HALF_UP. Would you rather use bankers rounding; just
# pass it as an argument.
n = Cash.new(2.5)
n.cents #=> 3

n = Cash.new(2.5, rounding_method: BigDecimal::ROUND_HALF_EVEN)
n.cents #=> 2

# Sick of specifying :cents_in_whole, :rounding_method and :currency; just
# set their defaults.
Cash.default_cents_in_whole  = 10
Cash.default_rounding_method = BigDecimal::ROUND_DOWN
Cash.default_currency        = :EUR

n = Cash.new(100)
n.to_s     #=> "10.0"
n.to_f     #=> 10.0
n.currency #=> :EUR

n = Cash.new(1.9)
n.cents #=> 1

# If your currency object implements :cents_in_whole, we'll go ahead and
# use that.

module MyCurrency
  def self.cents_in_whole
    10
  end
end

n = Cash.new(9, :currency => MyCurrency)
n.to_f #=> 0.9