Class: TypeIsEnum::Enum

Inherits:
Object
  • Object
show all
Includes:
Comparable
Defined in:
lib/type_is_enum/enum.rb

Overview

Base class for typesafe enum classes.

Direct Known Subclasses

ValueEnum

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#key ⇒ Symbol (readonly)

The symbol key for the enum instance

Returns:

  • (Symbol) —

    the key



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# File 'lib/type_is_enum/enum.rb', line 103

def key
  @key
end

#ord ⇒ Integer (readonly)

The ordinal of the enum instance, in declaration order

Returns:

  • (Integer) —

    the ordinal



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# File 'lib/type_is_enum/enum.rb', line 107

def ord
  @ord
end

Class Method Details

.each {|self| ... } ⇒ Array<self>

Iterates over the set of enum instances

Yields:

  • (self) —

    Each instance of this enum, in declaration order

Returns:

  • (Array<self>) —

    All instances of this enum, in declaration order



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# File 'lib/type_is_enum/enum.rb', line 25

def each(&block)
  to_a.each(&block)
end

.each_with_index {|self, Integer| ... } ⇒ Array<self>

Iterates over the set of enum instances

Yields:

  • (self, Integer) —

    Each instance of this enum, in declaration order, with its ordinal index

Returns:

  • (Array<self>) —

    All instances of this enum, in declaration order



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# File 'lib/type_is_enum/enum.rb', line 33

def each_with_index(&block)
  to_a.each_with_index(&block)
end

.find_by_key(key) ⇒ self?

Looks up an enum instance based on its key

Parameters:

  • key (Symbol) —

    the key to look up

Returns:

  • (self, nil) —

    the corresponding enum instance, or nil



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# File 'lib/type_is_enum/enum.rb', line 48

def find_by_key(key)
  by_key[key]
end

.find_by_ord(ord) ⇒ self?

Looks up an enum instance based on its ordinal

Parameters:

  • ord (Integer) —

    the ordinal to look up

Returns:

  • (self, nil) —

    the corresponding enum instance, or nil



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# File 'lib/type_is_enum/enum.rb', line 55

def find_by_ord(ord)
  return nil if ord < 0 || ord > size
  as_array[ord]
end

.map {|self| ... } ⇒ Array

Iterates over the set of enum instances

Yields:

  • (self) —

    Each instance of this enum, in declaration order

Returns:

  • (Array) —

    An array containing the result of applying &block to each instance of this enum, in instance declaration order



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# File 'lib/type_is_enum/enum.rb', line 41

def map(&block)
  to_a.map(&block)
end

.size ⇒ Integer

Returns the number of enum instances

Returns:

  • (Integer) —

    the number of instances



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# File 'lib/type_is_enum/enum.rb', line 18

def size
  as_array ? as_array.length : 0
end

.to_a ⇒ Array<self>

Returns an array of the enum instances in declaration order

Returns:

  • (Array<self>) —

    All instances of this enum, in declaration order



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# File 'lib/type_is_enum/enum.rb', line 12

def to_a
  as_array.dup
end

Instance Method Details

#<=>(other) ⇒ Integer?

Compares two instances of the same enum class based on their declaration order

Parameters:

  • other (self) —

    the enum instance to compare

Returns:

  • (Integer, nil) —

    -1 if this value precedes other; 0 if the two are the same enum instance; 1 if this value follows other; nil if other is not an instance of this enum class



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# File 'lib/type_is_enum/enum.rb', line 114

def <=>(other)
  ord <=> other.ord if self.class == other.class
end

#hash ⇒ Fixnum

Generates a Fixnum hash value for this enum instance

Returns:

  • (Fixnum) —

    the hash value



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# File 'lib/type_is_enum/enum.rb', line 120

def hash
  @hash ||= begin
    result = 17
    result = 31 * result + self.class.hash
    result = 31 * result + ord
    result.is_a?(Fixnum) ? result : result.hash
  end
end

#name ⇒ Object 



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# File 'lib/type_is_enum/enum.rb', line 129

def name
  key.to_s
end

#to_s ⇒ Object 



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# File 'lib/type_is_enum/enum.rb', line 133

def to_s
  "#{self.class}::#{key} [#{ord}]"
end