Class: DoubleLinkedList::Element

Inherits:
Struct
  • Object
show all
Includes:
Enumerable
Defined in:
lib/double_linked_list/element.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#_next ⇒ Object Also known as: next

Returns the value of attribute _next

Returns:

  • (Object) —

    the current value of _next



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# File 'lib/double_linked_list/element.rb', line 2

def _next
  @_next
end

#datum ⇒ Object

Returns the value of attribute datum

Returns:

  • (Object) —

    the current value of datum



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# File 'lib/double_linked_list/element.rb', line 2

def datum
  @datum
end

#previous ⇒ Object Also known as: prev

Returns the value of attribute previous

Returns:

  • (Object) —

    the current value of previous



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# File 'lib/double_linked_list/element.rb', line 2

def previous
  @previous
end

Instance Method Details

#_each(&block) ⇒ Object

Avoid calling myself on finds



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# File 'lib/double_linked_list/element.rb', line 13

def _each(&block)
  _next.each(&block) if _next
end

#_reverse_each(&block) ⇒ Object

This is done to avoid calling self in the block For not finding myself as the first element in the list



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# File 'lib/double_linked_list/element.rb', line 35

def _reverse_each(&block)
  previous.reverse_each(&block) if previous
end

#append(datum) ⇒ Object 



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# File 'lib/double_linked_list/element.rb', line 44

def append(datum)
  new_last = Element.new(datum, self, nil)
  self._next = new_last
  new_last
end

#chunk_by(acc, &block) ⇒ Object 



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# File 'lib/double_linked_list/element.rb', line 50

def chunk_by(acc, &block)
  if acc.empty?
    acc << DoubleLinkedList.from_a(self.datum)
  else
    if block.call(self, acc.last, acc)
      acc << DoubleLinkedList.from_a(self.datum)
    else
      acc.last << self.datum
    end
  end
  _next ? _next.chunk_by(acc, &block) : acc
end

#each(&block) ⇒ Object 



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# File 'lib/double_linked_list/element.rb', line 7

def each(&block)
  block.call self
  _next.each(&block) if _next
end

#find(datum) ⇒ Object 



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# File 'lib/double_linked_list/element.rb', line 17

def find(datum)
  find_next_by do |elem|
    elem.datum == datum
  end
end

#find_next_by(exclude_self = true, &block) ⇒ Object 



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# File 'lib/double_linked_list/element.rb', line 28

def find_next_by(exclude_self = true, &block)
  method = exclude_self ? :_each : :each
  _finder(method, &block)
end

#find_previous_by(exclude_self = true, &block) ⇒ Object 



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# File 'lib/double_linked_list/element.rb', line 23

def find_previous_by(exclude_self = true, &block)
  method = exclude_self ? :_reverse_each : :reverse_each
  _finder(method, &block)
end

#reverse_each(&block) ⇒ Object 



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# File 'lib/double_linked_list/element.rb', line 39

def reverse_each(&block)
  block.call self
  previous.reverse_each(&block) if previous
end

#select_by(&block) ⇒ Object 



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# File 'lib/double_linked_list/element.rb', line 63

def select_by(&block)
  sequences = []
  find_multiple do |e|
    head_tail = block.call(e)
    if head_tail
      sequences << head_tail
    end
    head_tail
  end
  extract_sequences(sequences)
end