lib/unit_measurements/measurement.rb in unit_measurements-4.9.0 vs lib/unit_measurements/measurement.rb in unit_measurements-4.10.0

@@ -1,56 +1,180 @@
 # -*- encoding: utf-8 -*-
 # -*- frozen_string_literal: true -*-
 # -*- warn_indent: true -*-
 
 module UnitMeasurements
+  # @abstract
+  # The +UnitMeasurements::Measurement+ is the abstract class and serves as superclass
+  # for all the unit groups. It includes several modules that provide mathematical
+  # operations, comparison, conversion, formatting, and other functionalities.
+  #
+  # This class provides a comprehensive set of methods and functionality for working
+  # with measurements in different units. It includes robust error handling and
+  # supports conversion between units. Additionally, it ensures that measurements
+  # are consistently represented.
+  #
+  # You should not directly initialize a +Measurement+ instance. Instead, create
+  # specialized measurement types by subclassing +Measurement+ and providing
+  # specific units and conversions through the +build+ method defined in the
+  # +UnitMeasurements+ module.
+  #
+  # @see Arithmetic
+  # @see Comparison
+  # @see Conversion
+  # @see Formatter
+  # @see Math
+  # @author {Harshal V. Ladhe}[https://shivam091.github.io/]
+  # @since 1.0.0
   class Measurement
     include Arithmetic
     include Comparison
     include Conversion
     include Formatter
     include Math
 
+    # Regular expression to match conversion strings.
     CONVERSION_STRING_REGEXP = /(.+?)\s?(?:\s+(?:in|to|as)\s+(.+)|\z)/i.freeze
 
-    attr_reader :quantity, :unit
+    # Quantity of the measurement.
+    attr_reader :quantity
 
+    # The unit associated with the measurement.
+    attr_reader :unit
+
+    # Initializes a new instance of +Measurement+ with a specified +quantity+
+    # and +unit+.
+    #
+    # This method is intended to be overridden by subclasses and serves as a
+    # placeholder for common initialization logic. It raises an error if called
+    # directly on the abstract +Measurement+ class.
+    #
+    # @example Initializing the measurement with scientific number and unit:
+    #   UnitMeasurements::Length.new(BigDecimal(2), "km")
+    #   => 2.0 km
+    #
+    #   UnitMeasurements::Length.new("2e+2", "km")
+    #   => 200.0 km
+    #
+    # @example Initializing the measurement with complex number and unit:
+    #   UnitMeasurements::Length.new(Complex(2, 3), "km")
+    #   => 2+3i km
+    #
+    #   UnitMeasurements::Length.new("2+3i", "km")
+    #   => 2.0+3.0i km
+    #
+    # @example Initializing the measurement with rational or mixed rational number and unit:
+    #   UnitMeasurements::Length.new(Rational(2, 3), "km")
+    #   => 0.6666666666666666 km
+    #
+    #   UnitMeasurements::Length.new(2/3r, "km")
+    #   => 2/3 km
+    #
+    #   UnitMeasurements::Length.new("2/3", "km")
+    #   => 0.6666666666666666 km
+    #
+    #   UnitMeasurements::Length.new("½", "km")
+    #   => 0.5 km
+    #
+    # @example Initializing the measurement with ratio and unit:
+    #   UnitMeasurements::Length.new("1:2", "km")
+    #   => 0.5 km
+    #
+    # @param [Numeric|String] quantity The quantity of the measurement.
+    # @param [String|Unit] unit The unit of the measurement.
+    #
+    # @raise [BaseError] If +quantity+ or +unit+ is blank.
+    #
+    # @see BaseError
+    # @author {Harshal V. Ladhe}[https://shivam091.github.io/]
+    # @since 1.0.0
     def initialize(quantity, unit)
       raise BaseError, "Quantity cannot be blank." if quantity.blank?
       raise BaseError, "Unit cannot be blank." if unit.blank?
 
       @quantity = convert_quantity(quantity)
       @unit = unit_from_unit_or_name!(unit)
     end
 
+    # Converts the measurement to a +target_unit+.
+    #
+    # @example
+    #   UnitMeasurements::Length.new(1, "m").convert_to("cm")
+    #   => 100.0 cm
+    #
+    # @param [String|Symbol] target_unit The target unit for conversion.
+    #
+    # @return [Measurement]
+    #   A new +Measurement+ instance with the converted +quantity+ and
+    #   +target unit+.
+    #
+    # @author {Harshal V. Ladhe}[https://shivam091.github.io/]
+    # @since 1.0.0
     def convert_to(target_unit)
       target_unit = unit_from_unit_or_name!(target_unit)
 
       return self if target_unit == unit
 
       conversion_factor = (unit.conversion_factor / target_unit.conversion_factor)
 
       self.class.new((quantity * conversion_factor), target_unit)
     end
-    [:to, :in, :as].each { |method_alias| alias_method method_alias, :convert_to }
+    alias_method :to, :convert_to
+    alias_method :in, :convert_to
+    alias_method :as, :convert_to
 
+    # Converts the measurement to a +target_unit+ and updates the current instance.
+    #
+    # @example
+    #   UnitMeasurements::Length.new(1, "m").convert_to!("cm")
+    #   => 100.0 cm
+    #
+    # @param [String|Symbol] target_unit The target unit for conversion.
+    #
+    # @return [Measurement]
+    #   The current +Measurement+ instance with updated +quantity+ and +unit+.
+    #
+    # @author {Harshal V. Ladhe}[https://shivam091.github.io/]
+    # @since 1.0.0
     def convert_to!(target_unit)
       measurement = convert_to(target_unit)
       @quantity, @unit = measurement.quantity, measurement.unit
 
       self
     end
-    [:to!, :in!, :as!].each { |method_alias| alias_method method_alias, :convert_to! }
+    alias_method :to!, :convert_to!
+    alias_method :in!, :convert_to!
+    alias_method :as!, :convert_to!
 
+    # Returns an object representation of the +Measurement+.
+    #
+    # @param [TrueClass|FalseClass] dump If +true+, returns the dump representation.
+    #
+    # @return [Object] An object representation of the +Measurement+.
+    #
+    # @author {Harshal V. Ladhe}[https://shivam091.github.io/]
+    # @since 1.0.0
     def inspect(dump: false)
       dump ? super() : to_s
     end
 
+    # Returns a string representation of the +Measurement+.
+    #
+    # @return [String] A string representation of the +Measurement+.
+    #
+    # @author {Harshal V. Ladhe}[https://shivam091.github.io/]
+    # @since 1.0.0
     def to_s
       "#{quantity} #{unit}"
     end
 
+    # Returns the +quantity+ of the +measurement+.
+    #
+    # @return [Numeric] Quantity of the measurement.
+    #
+    # @author {Harshal V. Ladhe}[https://shivam091.github.io/]
+    # @since 1.5.0
     def quantity
       case @quantity
       when Rational
         @quantity.denominator == 1 ? @quantity.numerator : @quantity
       else
@@ -59,36 +183,145 @@
     end
 
     class << self
       extend Forwardable
 
-      def unit_group
-        raise BaseError, "`Measurement` does not have a `unit_group` object. You cannot directly use `Measurement`. Instead, build a new unit group by calling `UnitMeasurements.build`."
-      end
-
+      # Methods delegated from the unit group.
       def_delegators :unit_group, :primitive, :units, :unit_names, :unit_with_name_and_aliases,
                      :unit_names_with_aliases, :unit_for, :unit_for!, :defined?,
                      :unit_or_alias?, :[]
 
+      # Parses an input string and returns a +Measurement+ instance depending on
+      # the input string. This method first normalizes the +input+ internally,
+      # using the +Normalizer+ before parsing it using the +Parser+.
+      #
+      # If only the source unit is provided, it returns a new +Measurement+
+      # instance with the quantity in the source unit.If both source and target
+      # units are provided in the input string, it returns a new +Measurement+
+      # instance with the quantity converted to the target unit.
+      #
+      # @example Parsing string representing a complex number and source unit:
+      #   UnitMeasurements::Length.parse("2+3i km")
+      #   => 2.0+3.0i km
+      #
+      # @example Parsing string representing a complex number, source, and target units:
+      #   UnitMeasurements::Length.parse("2+3i km to m")
+      #   => 2000.0+3000.0i m
+      #
+      # @example Parsing string representing a rational or mixed rational number and source unit:
+      #   UnitMeasurements::Length.parse("½ km")
+      #   => 0.5 km
+      #
+      #   UnitMeasurements::Length.parse("2/3 km")
+      #   => 0.666666666666667 km
+      #
+      #   UnitMeasurements::Length.parse("2 ½ km")
+      #   => 2.5 km
+      #
+      #   UnitMeasurements::Length.parse("2 1/2 km")
+      #   => 2.5 km
+      #
+      # @example Parsing string representing a rational or mixed rational number, source, and target units:
+      #   UnitMeasurements::Length.parse("½ km to m")
+      #   => 500.0 km
+      #
+      #   UnitMeasurements::Length.parse("2/3 km to m")
+      #   => 666.666666666667 m
+      #
+      #   UnitMeasurements::Length.parse("2 ½ km to m")
+      #   => 2500.0 m
+      #
+      #   UnitMeasurements::Length.parse("2 1/2 km to m")
+      #   => 2500.0 m
+      #
+      # @example Parsing string representing a scientific number and source unit:
+      #   UnitMeasurements::Length.parse("2e² km")
+      #   => 200.0 km
+      #
+      #   UnitMeasurements::Length.parse("2e+2 km")
+      #   => 200.0 km
+      #
+      #   UnitMeasurements::Length.parse("2e⁻² km")
+      #   => 0.02 km
+      #
+      # @example Parsing string representing a scientific number, source, and target units:
+      #
+      #   UnitMeasurements::Length.parse("2e+2 km to m")
+      #   => 200000.0 m
+      #
+      #   UnitMeasurements::Length.parse("2e⁻² km to m")
+      #   => 20.0 m
+      #
+      # @example Parsing string representing a ratio and source unit:
+      #   UnitMeasurements::Length.parse("1:2 km")
+      #   => 0.5 km
+      #
+      # @example Parsing string representing a ratio, source, and target units:
+      #   UnitMeasurements::Length.parse("1:2 km to m")
+      #   => 500.0 m
+      #
+      # @param [String] input The input string to be parsed.
+      #
+      # @return [Measurement] The +Measurement+ instance.
+      #
+      # @see Parser
+      # @see Normalizer
+      # @see CONVERSION_STRING_REGEXP
+      # @see _parse
+      # @author {Harshal V. Ladhe}[https://shivam091.github.io/]
+      # @since 1.0.0
       def parse(input)
         input = Normalizer.normalize(input)
         source, target = input.match(CONVERSION_STRING_REGEXP)&.captures
 
         target ? _parse(source).convert_to(target) : _parse(source)
       end
 
       private
 
+      # @private
+      # The class attribute representing an instance of +UnitGroup+.
+      #
+      # @return [UnitGroup] An instance of +UnitGroup+.
+      #
+      # @raise [BaseError]
+      #   If directly invoked on +Measurement+ rather than its subclasses.
+      #
+      # @see UnitGroup
+      # @author {Harshal V. Ladhe}[https://shivam091.github.io/]
+      # @since 1.0.0
+      def unit_group
+        raise BaseError, "`Measurement` does not have a `unit_group` instance. You cannot directly use `Measurement`. Instead, build a new unit group by calling `UnitMeasurements.build`."
+      end
+
+      # @private
+      # Parses the normalized string to return the +Measurement+ instance.
+      #
+      # @param [String] string String to be parsed.
+      #
+      # @return [Measurement] The +Measurement+ instance.
+      #
+      # @author {Harshal V. Ladhe}[https://shivam091.github.io/]
+      # @since 1.0.0
       def _parse(string)
         quantity, unit = Parser.parse(string)
 
         new(quantity, unit)
       end
     end
 
     private
 
+    # @private
+    # Converts the measurement quantity to a suitable format for internal use.
+    #
+    # @param [Numeric|String] quantity The quantity of the measurement.
+    #
+    # @return [Numeric] The converted quantity.
+    #
+    # @author {Harshal V. Ladhe}[https://shivam091.github.io/]
+    # @since 1.0.0
     def convert_quantity(quantity)
       case quantity
       when Float
         BigDecimal(quantity, Float::DIG)
       when Integer
@@ -101,10 +334,20 @@
       else
         quantity
       end
     end
 
+    # @private
+    # Returns the +Unit+ instance associated with the +value+ provided.
+    #
+    # @param [String|Unit] value
+    #   The value representing a unit name or +Unit+ instance.
+    #
+    # @return [Unit] The +Unit+ instance associated with +value+.
+    #
+    # @author {Harshal V. Ladhe}[https://shivam091.github.io/]
+    # @since 1.0.0
     def unit_from_unit_or_name!(value)
-      value.is_a?(Unit) ? value : self.class.unit_group.unit_for!(value)
+      value.is_a?(Unit) ? value : self.class.send(:unit_group).unit_for!(value)
     end
   end
 end