用于计算和转换测量值的简单 Ruby gem_Ruby_代码_相关文件_下载

# Measurement [](https://github.com/mhuggins/ruby-measurement/actions/workflows/CI.yml) [](https://codeclimate.com/github/mhuggins/ruby-measurement) [ruby-measurement](https://github.com/mhuggins/ruby-measurement) is a simple Ruby gem for calculating and converting units of measure. ## Installation Add this line to your application's Gemfile: gem 'ruby-measurement' And then execute: $ bundle Or install it yourself as: $ gem install ruby-measurement ## Usage The `Measurement` class is responsible for parsing strings to determine the quantity entered as well as the unit of measure. This can be done through the `parse` method, which returns a `Measurement` object. Measurement.parse('3 feet') # => 3.0 ft. Measurement.parse('25 fl oz') # => 25.0 fl. oz. Measurement.parse('12 tonnes') # => 12.0 t Measurement.parse('25 "') # => 25.0 in. A measurement includes both a quantity and a unit. Refer to the "Units" section below for more details on how to interact with a unit. measurement = Measurement.parse('12 yd') # => 12.0 yd. measurement.quantity # => 12.0 measurement.unit # => yd. The `String` and `Numeric` classes have also been extended to simplify the parsing of measurement values. '12 yd'.to_measurement # => 12.0 yd. 20.to_measurement # => 20.0 count ### Units The `Measurement::Unit` class is used to represent the units for a measurement. Predefined units can be looked up via `Measurement::Unit[]`. unit = Measurement::Unit[:dozen] # => doz Similarly, the `String#to_unit` and `Symbol#to_unit` method can be used to accomplish the same thing. unit = 'dozen'.to_unit # => doz unit = :dozen.to_unit # => doz Units provide access to their names and aliases. unit.name # => "yd." unit.aliases # => ["yd.", "yd", "yard", "yards"] ### Converting units This gem allows you to convert among compatible units as long as a conversion has been supplied when defining a unit. The default supplied units include conversions among the same unit types (e.g.: converting feet to yards or meters to kilometers). measurement = Measurement.parse('3 feet') # => 3.0 ft. measurement.convert_to(:yards) # => 1.0 yd. measurement.convert_to(:in) # => 36.0 in. measurement.convert_to(:inches) # => 36.0 in. NOTE: Converting between metric and U.S. customary systems is currently not included by default. It is intended to be shipped in a future release. ### Calculations This gem allows you to add, subtract, multiply, or divide measurements that can be converted into one-another. measurement1 = Measurement.parse('3 feet') # => 3.0 ft. measurement2 = Measurement.parse('6 inch') # => 6.0 in. measurement1 + measurement2 # => 3.5 ft. Additionally, measurements can have basic math operations performed using basic numeric values. measurement = Measurement.parse('2 yards') # => 2.0 yd. measurement * 6 # => 12.0 yd. measurement / 5 # => 0.4 yd. measurement + 3 # => 5.0 yd. measurement - 1 # => 1.0 yd. measurement ** 2 # => 4.0 yd. ### Specifying units By default, ruby-measurement ships with common areas, lengths, volumes, and weights/masses for the metric and U.S. customary systems. This happens automatically when requiring the gem in the following manner. require 'ruby-measurement' To include just one of these systems of measure, require the gem in per the following. require 'ruby-measurement/measurement' # Metric units/conversions require 'ruby-measurement/definitions/metric' # U.S. customary units/conversions require 'ruby-measurement/definitions/us_customary' Additionally, specific categories of units of measure can be included per system. require 'ruby-measurement/measurement' # Metric units/conversions require 'ruby-measurement/definitions/metric/area' require 'ruby-measurement/definitions/metric/length' require 'ruby-measurement/definitions/metric/volume' require 'ruby-measurement/definitions/metric/weight' # U.S. customary units/conversions require 'ruby-measurement/definitions/us_customary/area' require 'ruby-measurement/definitions/us_customary/length' require 'ruby-measurement/definitions/us_customary/volume' require 'ruby-measurement/definitions/us_customary/weight' ### Defining custom units & conversions This gem also enabled you to define units of measure that aren't included by default. Measurement.define(:day) do |unit| unit.alias :days unit.convert_to(:week) { |value| value / 7.0 } unit.convert_to(:year) { |value| value / 365.0 } end Measurement.define(:wk) do |unit| unit.alias :week, :weeks unit.convert_to(:day) { |value| value * 7.0 } unit.convert_to(:year) { |value| value / 52.0 } end Measurement.define(:yr) do |unit| unit.alias :year, :years unit.convert_to(:day) { |value| value * 365.0 } unit.convert_to(:week) { |value| value * 52.0 } end Note that the first value passed to `Measurement.define` is the unit format that will be used when displaying a measurement. Measurement.parse('3 yr') # => 3.0 yr Measurement.parse('3 year') # => 3.0 yr Measurement.parse('3 years') # => 3.0 yr ### List all units names defined List all keys you can use as unit Measurement::Unit.names # => ['count','doz','dozen',...] ## 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 ## License ruby-measurement is released under the [MIT License](http://www.opensource.org/licenses/MIT).