Class: Dasht::List

Inherits:
Object
  • Object
show all
Defined in:
lib/dasht/list.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ List

Returns a new instance of List.



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# File 'lib/dasht/list.rb', line 20

def initialize
  @offset = 0
  @values = []
end

Instance Attribute Details

#offset ⇒ Object

Returns the value of attribute offset.



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# File 'lib/dasht/list.rb', line 18

def offset
  @offset
end

#values ⇒ Object

Returns the value of attribute values.



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# File 'lib/dasht/list.rb', line 17

def values
  @values
end

Instance Method Details

#append(data) ⇒ Object

Public: Add data to the list. Returns a pointer to the new data.



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# File 'lib/dasht/list.rb', line 61

def append(data)
  pointer = self.tail_pointer
  @values << data
  return pointer
end

#enum(start_pointer = nil, end_pointer = nil) ⇒ Object

Public: Return an enumerator that walks through the list, yielding data.



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# File 'lib/dasht/list.rb', line 48

def enum(start_pointer = nil, end_pointer = nil)
  index = _pointer_to_index(start_pointer || head_pointer)
  end_index = _pointer_to_index(end_pointer || tail_pointer)
  return Enumerator.new do |yielder|
    while index < end_index
      yielder << @values[index]
      index += 1
    end
  end
end

#get(pointer) ⇒ Object

Public: Get the value at a given pointer, or nil if the pointer is no longer valid.



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# File 'lib/dasht/list.rb', line 41

def get(pointer)
  index = _pointer_to_index(pointer)
  return @values[index]
end

#head_pointer ⇒ Object

Public: Get a pointer to the first value.



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# File 'lib/dasht/list.rb', line 30

def head_pointer
  return offset
end

#tail_pointer ⇒ Object

Public: Get a pointer to right after the last value.



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# File 'lib/dasht/list.rb', line 35

def tail_pointer
  return offset + @values.length
end

#to_s ⇒ Object 



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# File 'lib/dasht/list.rb', line 25

def to_s
  return @values.to_s
end

#trim_to(pointer) ⇒ Object

Public: Remove data up to (but not including) the specified pointer.



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# File 'lib/dasht/list.rb', line 68

def trim_to(pointer)
  return if pointer.nil?
  index = _pointer_to_index(pointer)
  @offset += index
  @values = @values.slice(index, @values.length)
  return
end

#trim_while(&block) ⇒ Object

Public: Walk through the list, removing links from the list while the block returns true. Stop when it returns false.



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# File 'lib/dasht/list.rb', line 78

def trim_while(&block)
  while (@values.length > 0) && yield(@values.first)
    @values.shift
    @offset += 1
  end
  return
end