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Contents
# -*- coding: utf-8 -*-
module TreeRb
#
# Executes a block when enter in a node
# The block are defined from on_enter_X methods
# The blocks take as argument the node and the parent_node
#
class CallbackTreeNodeVisitor2
attr_reader :root
def initialize(delegate = nil)
super()
@stack = []
@root = nil
@delegate = delegate
end
def on_enter_node(&block)
raise "already defined a delegate" if @delegate
@action_enter_tree_node = block
end
def on_visit_leaf(&block)
raise "already defined a delegate" if @delegate
@action_visit_leaf_node = block
end
def enter_node(src_tree_node)
dst_parent_node = @stack.empty? ? nil : @stack.last
dst_tree_node = @action_enter_tree_node.call(src_tree_node, dst_parent_node) if @action_enter_tree_node
dst_tree_node = @delegate.enter_node(src_tree_node, dst_parent_node) if @delegate and @delegate.respond_to? :enter_node
@root = dst_tree_node if @stack.empty?
@stack.push(dst_tree_node)
end
def exit_node(src_tree_node)
@stack.pop
end
#
# called when the tree node is not accessible or an exception is raise when the node is accessed
#
def cannot_enter_node( tree_node, error)
end
def visit_leaf(src_leaf_node)
parent_node = @stack.last
@action_visit_leaf_node.call(src_leaf_node, parent_node) if @action_visit_leaf_node
@delegate.visit_leaf(src_leaf_node, parent_node) if @delegate and @delegate.respond_to? :visit_leaf
end
end
end
Version data entries
10 entries across 10 versions & 1 rubygems