Class: TireSwing::NodeCreator

Inherits:
Object
  • Object
show all
Defined in:
lib/tire_swing/node_creator.rb

Instance Method Summary collapse

Constructor Details

#initialize(node_name, node_class) ⇒ NodeCreator

Creates a node creator for the given node type and class. This is meant to act as a stand-in for the treetop syntax node class. The node_name, although somewhat redundant, is used for filtering later on (see: array_of)



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# File 'lib/tire_swing/node_creator.rb', line 8

def initialize(node_name, node_class)
  @node_name, @node_class = node_name, node_class
end

Instance Method Details

#new(*args) ⇒ Object

Returns a new treetop syntax node to act as a standin for a normal syntax node. Before returning the node, this defines a build method on the syntax node that will instantiate the node class using the auto-build functionality. If this build method isn’t enough, you’ll have to define one yourself inline in the treetop gramamr.



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# File 'lib/tire_swing/node_creator.rb', line 17

def new(*args)
  parsed_node = Treetop::Runtime::SyntaxNode.new(*args)

  node_name, node_class = @node_name, @node_class # local scope for the block below

  # so the node knows how to build itself:
  parsed_node.meta_def :build do
    node_class.new(self)
  end

  # so the node can be filtered based on what kind of AST node it will build
  parsed_node.meta_def :node_to_build do
    node_name
  end

  parsed_node
end