Module: Flutterby::TreeWalker

Extended by:
TreeWalker
Included in:
TreeWalker
Defined in:
lib/flutterby/tree_walker.rb

Overview

A helper module with methods to walk across a node tree in various directions and variations and perform a block of code on each passed node.

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.walk_down(node, val = nil, &blk) ⇒ Object

Walk the graph from the root to the specified node. Just like #walk_up, except the block will be called on higher level nodes first.



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# File 'lib/flutterby/tree_walker.rb', line 19

def walk_down(node, val = nil, &blk)
  val = node.parent ? walk_up(node.parent, val, &blk) : val
  blk.call(node, val)
end

.walk_tree(node, val = nil, &blk) ⇒ Object

Walk the entire tree, top to bottom, starting with its root, and then descending into its child layers.



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# File 'lib/flutterby/tree_walker.rb', line 27

def walk_tree(node, val = nil, &blk)
  val = blk.call(node, val)

  node.children.each do |child|
    val = walk_tree(child, val, &blk)
  end

  val
end

.walk_up(node, val = nil, &blk) ⇒ Object

Walk the tree up, invoking the passed block for every node found on the way, passing the node as its only argument.



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# File 'lib/flutterby/tree_walker.rb', line 11

def walk_up(node, val = nil, &blk)
  val = blk.call(node, val)
  node.parent ? walk_up(node.parent, val, &blk) : val
end

Instance Method Details

#walk_down(node, val = nil, &blk) ⇒ Object

Walk the graph from the root to the specified node. Just like #walk_up, except the block will be called on higher level nodes first.



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# File 'lib/flutterby/tree_walker.rb', line 19

def walk_down(node, val = nil, &blk)
  val = node.parent ? walk_up(node.parent, val, &blk) : val
  blk.call(node, val)
end

#walk_tree(node, val = nil, &blk) ⇒ Object

Walk the entire tree, top to bottom, starting with its root, and then descending into its child layers.



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# File 'lib/flutterby/tree_walker.rb', line 27

def walk_tree(node, val = nil, &blk)
  val = blk.call(node, val)

  node.children.each do |child|
    val = walk_tree(child, val, &blk)
  end

  val
end

#walk_up(node, val = nil, &blk) ⇒ Object

Walk the tree up, invoking the passed block for every node found on the way, passing the node as its only argument.



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# File 'lib/flutterby/tree_walker.rb', line 11

def walk_up(node, val = nil, &blk)
  val = blk.call(node, val)
  node.parent ? walk_up(node.parent, val, &blk) : val
end