Tempura

Tempura is a library for temperature arithmetic, comparison, and conversion. Currently supported scales are Fahrenheit, Celsius, Kelvin, Delisle, Newton, Rankine, Réaumer, and Rømer.

Temperature objects may be instantiated directly—

Tempura::Celsius.new(100)

—or by using the methods defined on Numeric:

212.degrees_fahrenheit

Usage

Instantiation

Direct instantiation:

Tempura::Fahrenheit.new(212)

Via Numeric:

100.degrees_celsius

Conversion

Tempura::Temperature (each scales parent object) implements #to, which returns a Tempura::Conversion, which then may receive the name of a scale to convert to:

212.degrees_fahrenheit.to.celsius #=> <Tempura::Celsius...

Arithmetic

Subtract other temperatures of any scale, or native degrees:

it 'subtracts another temperature' do
  fahrenheit = Tempura::Fahrenheit.new(212)
  celsius = Tempura::Celsius.new(0)
  result = fahrenheit - celsius
  expect(result).to eq(180)
  expect(result).to be_a(Tempura::Fahrenheit)
end

it 'subtracts native degrees' do
  fahrenheit = Tempura::Fahrenheit.new(212)
  result = fahrenheit - 32
  expect(result).to eq(180)
  expect(result).to be_a(Tempura::Fahrenheit)
end

Add temperatures of any scale, or native degrees:

it 'adds another temperature' do
  fahrenheit = Tempura::Fahrenheit.new(212)
  celsius = Tempura::Celsius.new(0)
  result = fahrenheit + celsius
  expect(result).to eq(244)
  expect(result).to be_a(Tempura::Fahrenheit)
end

it 'adds native degrees' do
  fahrenheit = Tempura::Fahrenheit.new(212)
  result = fahrenheit + 32
  expect(result).to eq(244)
  expect(result).to be_a(Tempura::Fahrenheit)
end

Divide a temperature by a numeric:

it 'divides by a Numeric' do
  fahrenheit = Tempura::Fahrenheit.new(212)
  result = fahrenheit / 2
  expect(result).to eq(106)
  expect(result).to be_a(Tempura::Fahrenheit)
end

it 'can average an array of temperatures' do
  f = Tempura::Fahrenheit.new(212)
  c = Tempura::Celsius.new(100)
  r = Tempura::Rømer.new(60)
  k = Tempura::Kelvin.new(373.15)
  result = ((f + c + r + k) / 4 ).to_delisle
  expect(result).to eq(0)
  expect(result).to be_a(Tempura::Delisle)
end

Multiply a temperature by a numeric:

it 'multiplies by a Numeric' do
  fahrenheit = Tempura::Fahrenheit.new(212)
  result = fahrenheit * 2
  expect(result).to eq(424)
  expect(result).to be_a(Tempura::Fahrenheit)
end

Comparison

>, <, <=, >=, <=>, and == are supported. Temperatures of the same or different scales may be compared, or a temperature may be compared with native degrees.

Tempura::Fahrenheit.new(212) > Tempura::Celsius.new(99)
Tempura::Fahrenheit.new(212) < Tempura::Celsius.new(101)
Tempura::Fahrenheit.new(212) >= Tempura::Celsius.new(99)
Tempura::Fahrenheit.new(212) <= Tempura::Celsius.new(101)

scales = [
	   Tempura::Celsius.new(100),
	   Tempura::Delisle.new(0),
	   Tempura::Fahrenheit.new(212),
	   Tempura::Newton.new(33),
	   Tempura::Rankine.new(671.67),
	   Tempura::Réaumur.new(80),
	   Tempura::Rømer.new(60),
	 ]

scales.all? { |s1| scales.each { |s2| s1 == s2 } }
#=> true

Casting

Tempura::Fahrenheit.new(212).to_f
Tempura::Kelvin.new(373.15).to_i
Tempura::Celsius.new(100).to_d

Installation

Add this line to your application's Gemfile:

gem 'tempura'

And then execute:

$ bundle

Or install it yourself as:

$ gem install tempura

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request