Class: UnitMeasurements::Unit

Inherits:
Object
  • Object
show all
Defined in:
lib/unit_measurements/unit.rb

Overview

The UnitMeasurements::Unit class represents a unit of measurement and provides methods to interact with its properties and conversion factors.

Author:

Since:

  • 1.0.0

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, value:, aliases:, system:, unit_group: nil) ⇒ Unit

Initializes a new Unit instance.

Parameters:

  • name (String|Symbol) —

    The name of the unit.

  • value (String|Numeric) —

    The conversion value of the unit.

  • aliases (Array<String|Symbol>) —

    Alternative names for the unit.

  • system (String|Symbol|NilClass) —

    The system to which the unit belongs.

  • unit_group (UnitGroup|NilClass) (defaults to: nil) —

    The unit group to which the unit belongs.

Author:

Since:

  • 1.0.0



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# File 'lib/unit_measurements/unit.rb', line 66

def initialize(name, value:, aliases:, system:, unit_group: nil)
  @name = name.to_s.freeze
  @value = value
  @aliases = Set.new(aliases.map(&:to_s).sort.map(&:freeze)).freeze
  @system = system.to_s.freeze
  @unit_group = unit_group
end

Instance Attribute Details

#aliases ⇒ Set<String> (readonly)

A set of alternative names for the unit.

Returns:

  • (Set<String>) —

    A set of alternative names.

Author:

Since:

  • 1.0.0



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# File 'lib/unit_measurements/unit.rb', line 38

def aliases
  @aliases
end

#name ⇒ String (readonly)

The name of the unit.

Returns:

  • (String) —

    Name of the unit.

Author:

Since:

  • 1.0.0



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# File 'lib/unit_measurements/unit.rb', line 20

def name
  @name
end

#system ⇒ String (readonly)

The system to which the unit belongs (e.g., “metric”, “imperial”).

Returns:

  • (String) —

    Unit system in which the unit belongs.

Author:

Since:

  • 4.0.0



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# File 'lib/unit_measurements/unit.rb', line 46

def system
  @system
end

#unit_group ⇒ UnitGroup (readonly)

The unit group to which the unit belongs.

Returns:

  • (UnitGroup) —

    Unit group in which the unit belongs.

Author:

Since:

  • 1.0.0



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# File 'lib/unit_measurements/unit.rb', line 54

def unit_group
  @unit_group
end

#value ⇒ String|Numeric|Array<Numeric, String> (readonly)

The conversion value of the unit. It can be a numeric value or a string in the form of a number followed by a unit name (e.g., “10 m”).

Returns:

  • (String|Numeric|Array<Numeric, String>) —

    Conversion value of the unit.

Author:

Since:

  • 1.0.0



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# File 'lib/unit_measurements/unit.rb', line 30

def value
  @value
end

Instance Method Details

#conversion_factor ⇒ Numeric

Calculates the conversion factor for the unit. This method is recursively invoked to calculate the conversion factor of the unit, if unit conversion value is specified with respect to the other unit.

This method uses parse_value method to extract the conversion value and the unit.

Returns:

  • (Numeric) —

    The conversion factor as a numeric value.

See Also:

  • #parse_value

Author:

Since:

  • 1.0.0



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# File 'lib/unit_measurements/unit.rb', line 148

def conversion_factor
  return value if value.is_a?(Numeric)

  measurement_value, measurement_unit = parse_value(value)
  conversion_factor = unit_group.unit_for!(measurement_unit).conversion_factor

  conversion_factor * measurement_value
end

#inspect ⇒ Object

Returns an object representation of the unit, including its aliases if present.

Returns:

  • (Object) —

    An object representation of the unit.

Author:

Since:

  • 1.0.0



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# File 'lib/unit_measurements/unit.rb', line 131

def inspect
  aliases = "(#{@aliases.join(", ")})" if @aliases.any?
  "#<#{self.class.name}: #{name} #{aliases}>"
end

#names ⇒ Array<String>

Returns an array containing the name of the unit and its aliases, sorted alphabetically.

Examples:

UnitMeasurements::Length.new(1, "m").unit.names
=> ["m", "meter", "meters", "metre", "metres"]

Returns:

  • (Array<String>) —

    An array of unit names.

Author:

Since:

  • 1.0.0



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# File 'lib/unit_measurements/unit.rb', line 107

def names
  (aliases + [name]).sort.freeze
end

#to_s ⇒ String

Returns the name of the unit as a string.

Examples:

UnitMeasurements::Length.new(1, "m").unit.to_s
=> "m"

Returns:

  • (String) —

    The name of the unit.

Author:

Since:

  • 1.0.0



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# File 'lib/unit_measurements/unit.rb', line 121

def to_s
  name
end

#with(name: nil, value: nil, aliases: nil, system: nil, unit_group: nil) ⇒ Unit

Returns a new Unit instance with specified attributes.

Parameters:

  • name (String|Symbol) (defaults to: nil) —

    The new name of the unit.

  • value (String|Numeric) (defaults to: nil) —

    The new conversion value of the unit.

  • aliases (Set<String>) (defaults to: nil) —

    New alternative names for the unit.

  • system (String|Symbol|NilClass) (defaults to: nil) —

    The new system to which the unit belongs.

  • unit_group (UnitGroup|NilClass) (defaults to: nil) —

    The new unit group to which the unit belongs.

Returns:

  • (Unit) —

    A new unit with specified parameters.

Author:

Since:

  • 1.0.0



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# File 'lib/unit_measurements/unit.rb', line 86

def with(name: nil, value: nil, aliases: nil, system: nil, unit_group: nil)
  self.class.new(
    (name || self.name),
    value: (value || self.value),
    aliases: (aliases || self.aliases),
    system: (system || self.system),
    unit_group: (unit_group || self.unit_group)
  )
end