fling_units 1.1.1

Dependency-free, type-safe Dart unit conversion library. Decouple specific unit types you need to work with from the rest of your code.

A type safe Dart library for unit conversion. Pass around fully abstracted measurements safely and easily to keep your code simple!

Usage

Create an instance of the dimension type you want to measure:

Distance distanceToSeattle = Distance.ofKilometers(246);
Distance distanceToTheMoon = Distance.ofImperial(miles: 238900, feet: 42, inches: 6.3);

Convert to any other measurement type within that dimension:

double distanceToSeattleInMiles = distanceToSeattle.asMiles;
double distanceToSeattleInInches = distanceToSeattle.asInches;

Perform basic arithmetic:

Distance distanceToSeattleAndBack = distanceToSeattle * 2;
Distance distanceToTheMoon = distanceToUpperAtmosphere + distanceFromAtmosphereToMoon;
Distance distanceToTheEndsOfTheUniverse = Distance.infinite();
bool useTheCar = distanceToTravel >= Distance.ofMiles(1.5);

Built-in ordering:

[Distance.zero(), Distance.infinite(), Distance.ofMeters(3), Distance.ofFeet(3), Distance.ofYards(-2)].sort();
// produces [yards(-2), zero(), feet(3), meters(3), infinite()]

Abstract away the specific units your code needs by passing around the encapsulated types. It doesn't matter which units each portion of your code requires, they can be combined seamlessly:

Distance computeTotalDistanceWithWiggleRoom(final Distance targetDistance) {
  return targetDistance + Distance.ofMeters(3.0);
}

Ensure type safety:

var nonsense = distanceToSeattle + temperatureInNewYork;  // won't compile!

Express the certainty in your measurements correctly by setting a precision. Conversions will automatically provide appropriate significant digits:

var myHeight = Distance.ofMeters(1.5, precision: Precision(2));
var myHeightInInches = myHeight.asInches;  // 59.0

Supported Features

Operations

With few exceptions (due to the nature of those measurements), all measurements support:

• customizable precision for each measurement
• implement Comparable for built-in ordering among similar measurements
• compare two similar measurements (>, <, ==, !=, >=, <=)
• add or subtract two similar measurements (+, -)
• multiply or divide measurements by a scalar (*, /)
• negate measurements (unary -)
• compare magnitude of two measurements (~/, compareMagnitude)

Distance Units

Metric:

• picometers
• nanometers
• micrometers
• millimeters
• centimeters
• decimeters
• meters
• dekameters
• hectometers
• kilometers

Imperial:

• inches
• feet
• yards
• miles

Nautical:

• nautical miles

Area Units

Metric:

• square millimeters
• square centimeters
• square meters
• square kilometers

Imperial:

• square inches
• square feet
• square yards
• square miles

Volume Units

Metric:

• milliliters
• centiliters
• deciliters
• liters
• dekaliters
• hectoliters
• kiloliters
• cubic meter

Imperial:

• teaspoon
• tablespoon
• fluid ounce
• cup
• pint
• quart
• gallon
• cubic foot
• cubic inch

US:

• teaspoon
• tablespoon
• fluid ounce
• cup
• pint
• quart
• gallon
• legal cup

Temperature Units

• kelvin
• celcius
• fahrenheit

Time units

• picoseconds
• nanoseconds
• microseconds
• milliseconds
• seconds
• minutes
• hours
• days

Mass units

• milligrams
• centigrams
• decigrams
• grams
• dekagrams
• hectograms
• kilograms
• tonnes
• ounces
• pounds
• short (US) tons
• long (UK) tons