Contents

module TireSwing
  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)
    #
    def initialize(node_name, node_class)
      @node_name, @node_class = node_name, node_class
    end

    # 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.
    #
    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

  end
end

Version data entries

4 entries across 4 versions & 1 rubygems

Version	Path
aniero-tire_swing-0.0.3	lib/tire_swing/node_creator.rb
aniero-tire_swing-0.0.4	lib/tire_swing/node_creator.rb
aniero-tire_swing-0.0.5	lib/tire_swing/node_creator.rb
aniero-tire_swing-0.0.6	lib/tire_swing/node_creator.rb