class Containers::Queue
A Queue
is a container that keeps elements in a first-in first-out (FIFO) order. Because of its properties, it is often used as a buffer.
This implementation uses a doubly-linked list, guaranteeing O(1) complexity for all operations.
Public Class Methods
new(ary=[])
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Create a new queue. Takes an optional array argument to initialize the queue.
q = Containers::Queue.new([1, 2, 3]) q.pop #=> 1 q.pop #=> 2
# File lib/containers/queue.rb 17 def initialize(ary=[]) 18 @container = Containers::Deque.new(ary) 19 end
Public Instance Methods
each(&block)
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Iterate over the Queue
in FIFO order.
# File lib/containers/queue.rb 64 def each(&block) 65 @container.each_forward(&block) 66 end
empty?()
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Returns true if the queue is empty, false otherwise.
# File lib/containers/queue.rb 59 def empty? 60 @container.empty? 61 end
next()
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Returns the next item from the queue but does not remove it.
q = Containers::Queue.new([1, 2, 3]) q.next #=> 1 q.size #=> 3
# File lib/containers/queue.rb 26 def next 27 @container.front 28 end
pop()
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Removes the next item from the queue and returns it.
q = Containers::Queue.new([1, 2, 3]) q.pop #=> 1 q.size #=> 2
# File lib/containers/queue.rb 46 def pop 47 @container.pop_front 48 end
push(obj)
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Adds an item to the queue.
q = Containers::Queue.new([1]) q.push(2) q.pop #=> 1 q.pop #=> 2
# File lib/containers/queue.rb 36 def push(obj) 37 @container.push_back(obj) 38 end
Also aliased as: <<
size()
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Return the number of items in the queue.
q = Containers::Queue.new([1, 2, 3]) q.size #=> 3
# File lib/containers/queue.rb 54 def size 55 @container.size 56 end