Class: Async::Node

Inherits:
Object
  • Object
show all
Defined in:
lib/async/node.rb

Overview

Represents a node in a tree, used for nested Task instances.

Direct Known Subclasses

Reactor, Task

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(parent = nil) ⇒ Node

Create a new node in the tree.

Parameters:

  • parent (Node, nil) (defaults to: nil) —

    This node will attach to the given parent.



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# File 'lib/async/node.rb', line 28

def initialize(parent = nil)
	@children = nil
	@parent = nil
	
	@annotation = nil
	@object_name = nil
	
	if parent
		self.parent = parent
	end
end

Instance Attribute Details

#annotation ⇒ Object (readonly)

A useful identifier for the current node.



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# File 'lib/async/node.rb', line 47

def annotation
  @annotation
end

#children ⇒ Object (readonly) 



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# File 'lib/async/node.rb', line 44

def children
  @children
end

#parent ⇒ Object 



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# File 'lib/async/node.rb', line 41

def parent
  @parent
end

Instance Method Details

#annotate(annotation) ⇒ Object 



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# File 'lib/async/node.rb', line 49

def annotate(annotation)
	if block_given?
		previous_annotation = @annotation
		@annotation = annotation
		yield
		@annotation = previous_annotation
	else
		@annotation = annotation
	end
end

#consume ⇒ Object

If the node has a parent, and is #finished?, then remove this node from the parent.



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# File 'lib/async/node.rb', line 107

def consume
	if @parent and finished?
		@parent.reap(self)
		@parent.consume
		@parent = nil
	end
end

#description ⇒ Object 



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# File 'lib/async/node.rb', line 60

def description
	@object_name ||= "#{self.class}:0x#{object_id.to_s(16)}"
	
	if @annotation
		"#{@object_name} #{@annotation}"
	else
		@object_name
	end
end

#finished? ⇒ Boolean

Whether the node can be consumed safely. By default, checks if the children set is empty.

Returns:

  • (Boolean) 


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# File 'lib/async/node.rb', line 101

def finished?
	@children.nil? or @children.empty?
end

#print_hierarchy(out = $stdout) ⇒ Object 



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# File 'lib/async/node.rb', line 131

def print_hierarchy(out = $stdout)
	self.traverse do |node, level|
		out.puts "#{"\t" * level}#{node}"
	end
end

#reap(child) ⇒ Object

Remove a given child node.

Parameters:



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# File 'lib/async/node.rb', line 117

def reap(child)
	@children.delete(child)
end

#to_s ⇒ Object 



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# File 'lib/async/node.rb', line 70

def to_s
	"\#<#{description}>"
end

#traverse(level = 0) {|node, level| ... } ⇒ Object

Traverse the tree.

Yields:

  • (node, level) —

    The node and the level relative to the given root.



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# File 'lib/async/node.rb', line 123

def traverse(level = 0, &block)
	yield self, level
	
	@children&.each do |child|
		child.traverse(level + 1, &block)
	end
end